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Linus Torvalds d665ea6ea8 This pull request contains the following changes for UML:
- Disable CONFIG_GCOV when built with modules
 - Many fixes for W=1 related warnings
 - Code cleanup
 
 Due to lack of time I was unable to prepare a bigger pull request.
 PR for the next merge window will contain more interesting material, I promise. :-)
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Merge tag 'for-linus-5.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml

Pull UML updates from Richard Weinberger:

 - Disable CONFIG_GCOV when built with modules

 - Many fixes for W=1 related warnings

 - Code cleanup

* tag 'for-linus-5.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml:
  um: Fix W=1 missing-include-dirs warnings
  um: elf.h: Fix W=1 warning for empty body in 'do' statement
  um: pgtable.h: Fix W=1 warning for empty body in 'do' statement
  um: Remove unused including <linux/version.h>
  um: Add 2 missing libs to fix various build errors
  um: Replace if (cond) BUG() with BUG_ON()
  um: Disable CONFIG_GCOV with MODULES
  um: Remove unneeded variable 'ret'
  um: Mark all kernel symbols as local
  um: Fix tag order in stub_32.h
2021-05-04 18:15:10 -07:00
Kefeng Wang 1f9d03c5e9 mm: move mem_init_print_info() into mm_init()
mem_init_print_info() is called in mem_init() on each architecture, and
pass NULL argument, so using void argument and move it into mm_init().

Link: https://lkml.kernel.org/r/20210317015210.33641-1-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>	[x86]
Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr>	[powerpc]
Acked-by: David Hildenbrand <david@redhat.com>
Tested-by: Anatoly Pugachev <matorola@gmail.com>	[sparc64]
Acked-by: Russell King <rmk+kernel@armlinux.org.uk>	[arm]
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Guo Ren <guoren@kernel.org>
Cc: Yoshinori Sato <ysato@users.osdn.me>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: "Peter Zijlstra" <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-04-30 11:20:42 -07:00
Linus Torvalds 7f3d08b255 printk changes for 5.13
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Merge tag 'printk-for-5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux

Pull printk updates from Petr Mladek:

 - Stop synchronizing kernel log buffer readers by logbuf_lock. As a
   result, the access to the buffer is fully lockless now.

   Note that printk() itself still uses locks because it tries to flush
   the messages to the console immediately. Also the per-CPU temporary
   buffers are still there because they prevent infinite recursion and
   serialize backtraces from NMI. All this is going to change in the
   future.

 - kmsg_dump API rework and cleanup as a side effect of the logbuf_lock
   removal.

 - Make bstr_printf() aware that %pf and %pF formats could deference the
   given pointer.

 - Show also page flags by %pGp format.

 - Clarify the documentation for plain pointer printing.

 - Do not show no_hash_pointers warning multiple times.

 - Update Senozhatsky email address.

 - Some clean up.

* tag 'printk-for-5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux: (24 commits)
  lib/vsprintf.c: remove leftover 'f' and 'F' cases from bstr_printf()
  printk: clarify the documentation for plain pointer printing
  kernel/printk.c: Fixed mundane typos
  printk: rename vprintk_func to vprintk
  vsprintf: dump full information of page flags in pGp
  mm, slub: don't combine pr_err with INFO
  mm, slub: use pGp to print page flags
  MAINTAINERS: update Senozhatsky email address
  lib/vsprintf: do not show no_hash_pointers message multiple times
  printk: console: remove unnecessary safe buffer usage
  printk: kmsg_dump: remove _nolock() variants
  printk: remove logbuf_lock
  printk: introduce a kmsg_dump iterator
  printk: kmsg_dumper: remove @active field
  printk: add syslog_lock
  printk: use atomic64_t for devkmsg_user.seq
  printk: use seqcount_latch for clear_seq
  printk: introduce CONSOLE_LOG_MAX
  printk: consolidate kmsg_dump_get_buffer/syslog_print_all code
  printk: refactor kmsg_dump_get_buffer()
  ...
2021-04-27 18:09:44 -07:00
Yang Li 24271ffed7 um: Replace if (cond) BUG() with BUG_ON()
Fix the following coccinelle reports:
./arch/um/kernel/mem.c:77:3-6: WARNING: Use BUG_ON instead of if
condition followed by BUG.

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Yang Li <yang.lee@linux.alibaba.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2021-04-15 23:10:37 +02:00
Johannes Berg ad3d199116 um: Disable CONFIG_GCOV with MODULES
CONFIG_GCOV doesn't work with modules, and for various reasons
it cannot work, see also
https://lore.kernel.org/r/d36ea54d8c0a8dd706826ba844a6f27691f45d55.camel@sipsolutions.net

Make CONFIG_GCOV depend on !MODULES to avoid anyone
running into issues there. This also means we need
not export the gcov symbols.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2021-04-15 23:10:33 +02:00
Johannes Berg d5027ca63e um: Mark all kernel symbols as local
Ritesh reported a bug [1] against UML, noting that it crashed on
startup. The backtrace shows the following (heavily redacted):

(gdb) bt
...
 #26 0x0000000060015b5d in sem_init () at ipc/sem.c:268
 #27 0x00007f89906d92f7 in ?? () from /lib/x86_64-linux-gnu/libcom_err.so.2
 #28 0x00007f8990ab8fb2 in call_init (...) at dl-init.c:72
...
 #40 0x00007f89909bf3a6 in nss_load_library (...) at nsswitch.c:359
...
 #44 0x00007f8990895e35 in _nss_compat_getgrnam_r (...) at nss_compat/compat-grp.c:486
 #45 0x00007f8990968b85 in __getgrnam_r [...]
 #46 0x00007f89909d6b77 in grantpt [...]
 #47 0x00007f8990a9394e in __GI_openpty [...]
 #48 0x00000000604a1f65 in openpty_cb (...) at arch/um/os-Linux/sigio.c:407
 #49 0x00000000604a58d0 in start_idle_thread (...) at arch/um/os-Linux/skas/process.c:598
 #50 0x0000000060004a3d in start_uml () at arch/um/kernel/skas/process.c:45
 #51 0x00000000600047b2 in linux_main (...) at arch/um/kernel/um_arch.c:334
 #52 0x000000006000574f in main (...) at arch/um/os-Linux/main.c:144

indicating that the UML function openpty_cb() calls openpty(),
which internally calls __getgrnam_r(), which causes the nsswitch
machinery to get started.

This loads, through lots of indirection that I snipped, the
libcom_err.so.2 library, which (in an unknown function, "??")
calls sem_init().

Now, of course it wants to get libpthread's sem_init(), since
it's linked against libpthread. However, the dynamic linker
looks up that symbol against the binary first, and gets the
kernel's sem_init().

Hajime Tazaki noted that "objcopy -L" can localize a symbol,
so the dynamic linker wouldn't do the lookup this way. I tried,
but for some reason that didn't seem to work.

Doing the same thing in the linker script instead does seem to
work, though I cannot entirely explain - it *also* works if I
just add "VERSION { { global: *; }; }" instead, indicating that
something else is happening that I don't really understand. It
may be that explicitly doing that marks them with some kind of
empty version, and that's different from the default.

Explicitly marking them with a version breaks kallsyms, so that
doesn't seem to be possible.

Marking all the symbols as local seems correct, and does seem
to address the issue, so do that. Also do it for static link,
nsswitch libraries could still be loaded there.

[1] https://bugs.debian.org/983379

Reported-by: Ritesh Raj Sarraf <rrs@debian.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Acked-By: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Tested-By: Ritesh Raj Sarraf <rrs@debian.org>
Signed-off-by: Richard Weinberger <richard@nod.at>
2021-04-15 23:10:29 +02:00
John Ogness f9f3f02db9 printk: introduce a kmsg_dump iterator
Rather than storing the iterator information in the registered
kmsg_dumper structure, create a separate iterator structure. The
kmsg_dump_iter structure can reside on the stack of the caller, thus
allowing lockless use of the kmsg_dump functions.

Update code that accesses the kernel logs using the kmsg_dumper
structure to use the new kmsg_dump_iter structure. For kmsg_dumpers,
this also means adding a call to kmsg_dump_rewind() to initialize
the iterator.

All this is in preparation for removal of @logbuf_lock.

Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Kees Cook <keescook@chromium.org> # pstore
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20210303101528.29901-13-john.ogness@linutronix.de
2021-03-08 11:43:27 +01:00
John Ogness fdd2c1f4e2 um: synchronize kmsg_dumper
The kmsg_dumper can be called from any context and CPU, possibly
from multiple CPUs simultaneously. Since a static buffer is used
to retrieve the kernel logs, this buffer must be protected against
simultaneous dumping. Skip dumping if another context is already
dumping.

Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20210303101528.29901-2-john.ogness@linutronix.de
2021-03-08 11:42:37 +01:00
Jens Axboe 4727dc20e0 arch: setup PF_IO_WORKER threads like PF_KTHREAD
PF_IO_WORKER are kernel threads too, but they aren't PF_KTHREAD in the
sense that we don't assign ->set_child_tid with our own structure. Just
ensure that every arch sets up the PF_IO_WORKER threads like kthreads
in the arch implementation of copy_thread().

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-02-21 17:25:22 -07:00
Johannes Berg dde8b58d51 um: add a pseudo RTC
Add a pseudo RTC that simply is able to send an alarm signal
waking up the system at a given time in the future.

Since apparently timerfd_create() FDs don't support SIGIO, we
use the sigio-creating helper thread, which just learned to do
suspend/resume properly in the previous patch.

For time-travel mode, OTOH, just add an event at the specified
time in the future, and that's already sufficient to wake up
the system at that point in time since suspend will just be in
an "endless wait".

For s2idle support also call pm_system_wakeup().

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2021-02-12 21:38:52 +01:00
Johannes Berg bfc58e2b98 um: remove process stub VMA
This mostly reverts the old commit 3963333fe6 ("uml: cover stubs
with a VMA") which had added a VMA to the existing PTEs. However,
there's no real reason to have the PTEs in the first place and the
VMA cannot be 'fixed' in place, which leads to bugs that userspace
could try to unmap them and be forcefully killed, or such. Also,
there's a bit of an ugly hole in userspace's address space.

Simplify all this: just install the stub code/page at the top of
the (inner) address space, i.e. put it just above TASK_SIZE. The
pages are simply hard-coded to be mapped in the userspace process
we use to implement an mm context, and they're out of reach of the
inner mmap/munmap/mprotect etc. since they're above TASK_SIZE.

Getting rid of the VMA also makes vma_merge() no longer hit one of
the VM_WARN_ON()s there because we installed a VMA while the code
assumes the stack VMA is the first one.

It also removes a lockdep warning about mmap_sem usage since we no
longer have uml_setup_stubs() and thus no longer need to do any
manipulation that would require mmap_sem in activate_mm().

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2021-02-12 21:37:38 +01:00
Johannes Berg 9f0b4807a4 um: rework userspace stubs to not hard-code stub location
The userspace stacks mostly have a stack (and in the case of the
syscall stub we can just set their stack pointer) that points to
the location of the stub data page already.

Rework the stubs to use the stack pointer to derive the start of
the data page, rather than requiring it to be hard-coded.

In the clone stub, also integrate the int3 into the stack remap,
since we really must not use the stack while we remap it.

This prepares for putting the stub at a variable location that's
not part of the normal address space of the userspace processes
running inside the UML machine.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2021-02-12 21:35:02 +01:00
Johannes Berg 84b2789d61 um: separate child and parent errors in clone stub
If the two are mixed up, then it looks as though the parent
returned an error if the child failed (before) the mmap(),
and then the resulting process never gets killed. Fix this
by splitting the child and parent errors, reporting and
using them appropriately.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2021-02-12 21:34:33 +01:00
Johannes Berg a7d48886ca um: defer killing userspace on page table update failures
In some cases we can get to fix_range_common() with mmap_sem held,
and in others we get there without it being held. For example, we
get there with it held from sys_mprotect(), and without it held
from fork_handler().

Avoid any issues in this and simply defer killing the task until
it runs the next time. Do it on the mm so that another task that
shares the same mm can't continue running afterwards.

Cc: stable@vger.kernel.org
Fixes: 468f65976a ("um: Fix hung task in fix_range_common()")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2021-02-12 21:32:04 +01:00
Johannes Berg 47da29763e um: mm: check more comprehensively for stub changes
If userspace tries to change the stub, we need to kill it,
because otherwise it can escape the virtual machine. In a
few cases the stub checks weren't good, e.g. if userspace
just tries to

	mmap(0x100000 - 0x1000, 0x3000, ...)

it could succeed to get a new private/anonymous mapping
replacing the stubs. Fix this by checking everywhere, and
checking for _overlap_, not just direct changes.

Cc: stable@vger.kernel.org
Fixes: 3963333fe6 ("uml: cover stubs with a VMA")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2021-02-12 21:31:08 +01:00
Johannes Berg c8177aba37 um: time-travel: rework interrupt handling in ext mode
In external time-travel mode, where time is controlled via the
controller application socket, interrupt handling is a little
tricky. For example on virtio, the following happens:
 * we receive a message (that requires an ACK) on the vhost-user socket
 * we add a time-travel event to handle the interrupt
   (this causes communication on the time socket)
 * we ACK the original vhost-user message
 * we then handle the interrupt once the event is triggered

This protocol ensures that the sender of the interrupt only continues
to run in the simulation when the time-travel event has been added.

So far, this was only done in the virtio driver, but it was actually
wrong, because only virtqueue interrupts were handled this way, and
config change interrupts were handled immediately. Additionally, the
messages were actually handled in the real Linux interrupt handler,
but Linux interrupt handlers are part of the simulation and shouldn't
run while there's no time event.

To really do this properly and only handle all kinds of interrupts in
the time-travel event when we are scheduled to run in the simulation,
rework this to plug in to the lower interrupt layers in UML directly:

Add a um_request_irq_tt() function that let's a time-travel aware
driver request an interrupt with an additional timetravel_handler()
that is called outside of the context of the simulation, to handle
the message only. It then adds an event to the time-travel calendar
if necessary, and no "real" Linux code runs outside of the time
simulation.

This also hooks in with suspend/resume properly now, since this new
timetravel_handler() can run while Linux is suspended and interrupts
are disabled, and decide to wake up (or not) the system based on the
message it received. Importantly in this case, it ACKs the message
before the system even resumes and interrupts are re-enabled, thus
allowing the simulation to progress properly.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2021-02-12 21:24:27 +01:00
Johannes Berg 7f3414226b um: time: fix initialization in time-travel mode
In time-travel mode, since my previous patch, the start time was
initialized too late, so that the system would read it before we
set it, thus always starting system time at 0 (1970-01-01). This
happens because timekeeping_init() reads the time and is called
before time_init().

Unfortunately, I didn't see this before because I was testing it
only with the RTC patch applied (and enabled), and then the time
is read again by the RTC a little - after time_init() this time.

Fix this by just doing the initialization whenever necessary.

Fixes: 2701c1bd91 ("um: time: Fix read_persistent_clock64() in time-travel")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2021-01-26 22:11:38 +01:00
Johannes Berg a31e9c4e72 Revert "um: support some of ARCH_HAS_SET_MEMORY"
This reverts commit 963285b0b4 ("um: support some of
ARCH_HAS_SET_MEMORY"), as it turns out that it's not only not
working (due to um never using the protection bits in the
page tables) but also corrupts the page tables if used on a
non-vmalloc page, since um never allocates proper page tables
for the 'physmem' in the first place.

Fixing all this will take more effort, so for now revert it.

Reported-by: Benjamin Berg <benjamin@sipsolutions.net>
Fixes: 963285b0b4 ("um: support some of ARCH_HAS_SET_MEMORY")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2021-01-26 22:11:38 +01:00
Johannes Berg 2fcb4090cd Revert "um: allocate a guard page to helper threads"
This reverts commit ef4459a6da ("um: allocate a guard page to
helper threads"), it's broken in multiple ways:

 1) the free no longer matches the alloc; and

 2) more importantly, the set_memory_ro() causes allocation of
    page tables for the normal memory that doesn't have any,
    and that later causes corruption and crashes (usually but
    not always in vfree()).

We could fix the first bug and use vmalloc() to work around the
second, but set_memory_ro() actually doesn't do anything either
so I'll just revert that as well.

Reported-by: Benjamin Berg <benjamin@sipsolutions.net>
Fixes: ef4459a6da ("um: allocate a guard page to helper threads")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2021-01-26 22:11:38 +01:00
Thomas Meyer e23fe90dec um: kmsg_dumper: always dump when not tty console
With the addition of the ttynull console driver, the chance that a
console driver was already registerd did increase. Refine the logic when
to dump the kernel message buffer: always dump the buffer, when the UML
stdio console driver is not active and the preferred console.

Signed-off-by: Thomas Meyer <thomas@m3y3r.de>
Signed-off-by: Richard Weinberger <richard@nod.at>
2021-01-26 22:11:37 +01:00
Thomas Meyer d7ffac3363 um: stdio_console: Make preferred console
The addition of the "ttynull" console driver did break the ordering of the
UML stdio console driver.
The UML stdio console driver is added in late_initcall (7), whereby the
ttynull driver is added in device_initcall (6), which always does make the
ttynull driver the default console.

Fix it by explicitly adding the UML stdio console as the preferred console,
in case no 'console=' command line option was specified.

Signed-off-by: Thomas Meyer <thomas@m3y3r.de>
Signed-off-by: Richard Weinberger <richard@nod.at>
2021-01-26 22:11:37 +01:00
Johannes Berg 1fb1abc836 um: Fix build w/o CONFIG_PM_SLEEP
uml_pm_wake() is unconditionally called from the SIGUSR1 wakeup
handler since that's in the userspace portion of UML, and thus
a bit tricky to ifdef out. Since pm_system_wakeup() can always
be called (but may be an empty inline), also simply always have
uml_pm_wake() to fix the build.

Reported-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Randy Dunlap <rdunlap@infradead.org> # build-tested
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2020-12-14 21:15:32 +01:00
Johannes Berg 11385539c0 um: time-travel: Correct time event IRQ delivery
Lockdep (on 5.10-rc) points out that we're delivering IRQs while IRQs
are not even enabled, which clearly shouldn't happen. Defer the time
event IRQ delivery until they actually are enabled.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2020-12-13 22:42:06 +01:00
Johannes Berg cae20ba0a1 um: irq/sigio: Support suspend/resume handling of workaround IRQs
If the sigio workaround needed to be applied to a file descriptor,
set_irq_wake() wouldn't work for it since it would get polled by
the thread instead of causing SIGIO, and thus could never really
cause a wakeup, since the thread notification FD wasn't marked as
being able to wake up the system.

Fix this by marking the thread's notification FD explicitly as a
wake source FD, i.e. not suppressing SIGIO for it in suspend. In
order to not cause spurious wakeups, we then need to remove all
FDs that shouldn't wake up the system from the polling thread. In
order to do this, add unlocked versions of ignore_sigio_fd() and
add_sigio_fd() (nothing else is happening in suspend, so this is
fine), and also modify ignore_sigio_fd() to return -ENOENT if the
FD wasn't originally in there. This doesn't matter because nothing
else currently checks the return value, but the irq code needs to
know which ones to restore the workaround for.

All told, this lets us use a timerfd for the RTC clock in the next
patch, which doesn't send SIGIO.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2020-12-13 22:42:01 +01:00
Johannes Berg 452f94cecf um: time-travel: Actually apply "free-until" optimisation
Due a bug - we never checked the time_travel_ext_free_until value - we
were always requesting time for every single scheduling. This adds up
since we make reading time cost 256ns, and it's a fairly common call.
Fix this.

While at it, also make reading time only cost something when we're not
currently waiting for our scheduling turn - otherwise things get mixed
up in a very confusing way. We should never get here, since we're not
actually running, but it's possible if you stick printk() or such into
the virtio code that must handle the external interrupts.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2020-12-13 22:41:56 +01:00
Johannes Berg ef4459a6da um: allocate a guard page to helper threads
We've been running into stack overflows in helper threads
corrupting memory (e.g. because somebody put printf() or
os_info() there), so to avoid those causing hard-to-debug
issues later on, allocate a guard page for helper thread
stacks and mark it read-only.

Unfortunately, the crash dump at that point is useless as
the stack tracer will try to backtrace the *kernel* thread,
not the helper thread, but at least we don't survive to a
random issue caused by corruption.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2020-12-13 22:38:06 +01:00
Johannes Berg 963285b0b4 um: support some of ARCH_HAS_SET_MEMORY
For now, only support set_memory_ro()/rw() which we need for
the stack protection in the next patch.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2020-12-13 22:38:06 +01:00
Johannes Berg 58b09f6869 um: time-travel: avoid multiple identical propagations
If there is some kind of interrupt negotation or such then
it may happen that we send an update message multiple times,
avoid that in the interest of efficiency by storing the last
transmitted value and only sending a new update if it's not
the same as the last update.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2020-12-13 22:38:06 +01:00
Johannes Berg a374b7cb1e um: Support suspend to RAM
With all the previous bits in place, we can now also support
suspend to RAM, in the sense that everything is suspended,
not just most, including userspace, processes like in s2idle.

Since um_idle_sleep() now waits forever, we can simply call
that to "suspend" the system.

As before, you can wake it up using SIGUSR1 since we're just
in a pause() call that only needs to return.

In order to implement selective resume from certain devices,
and not have any arbitrary device interrupt wake up, suspend
interrupts by removing SIGIO notification (O_ASYNC) from all
the FDs that are not supposed to wake up the system. However,
swap out the handler so we don't actually handle the SIGIO as
an interrupt.

Since we're in pause(), the mere act of receiving SIGIO wakes
us up, and then after things have been restored enough, re-set
O_ASYNC for all previously suspended FDs, reinstall the proper
SIGIO handler, and send SIGIO to self to process anything that
might now be pending.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2020-12-13 22:22:49 +01:00
Johannes Berg 92dcd3d318 um: Allow PM with suspend-to-idle
In order to be able to experiment with suspend in UML, add the
minimal work to be able to suspend (s2idle) an instance of UML,
and be able to wake it back up from that state with the USR1
signal sent to the main UML process.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Acked-By: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2020-12-13 22:22:46 +01:00
Johannes Berg 2701c1bd91 um: time: Fix read_persistent_clock64() in time-travel
In time-travel mode, we've relied on read_persistent_clock64()
being called only once at system startup, but this is both the
right thing to call from the pseudo-RTC, and also gets called
by the timekeeping core during suspend/resume.

Thus, fix this to always fall make use of the time_travel_time
in any time-travel mode, initializing time_travel_start at boot
to the right value depending on the time-travel mode.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Acked-By: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2020-12-13 22:22:41 +01:00
Johannes Berg 49da38a3ef um: Simplify os_idle_sleep() and sleep longer
There really is no reason to pass the amount of time we should
sleep, especially since it's just hard-coded to one second.

Additionally, one second isn't really all that long, and as we
are expecting to be woken up by a signal, we can sleep longer
and avoid doing some work every second, so replace the current
clock_nanosleep() with just an empty select() that can _only_
be woken up by a signal.

We can also remove the deliver_alarm() since we don't need to
do that when we got e.g. SIGIO that woke us up, and if we got
SIGALRM the signal handler will actually (have) run, so it's
just unnecessary extra work.

Similarly, in time-travel mode, just program the wakeup event
from idle to be S64_MAX, which is basically the most you could
ever simulate to. Of course, you should already have an event
in the list that's earlier and will cause a wakeup, normally
that's the regular timer interrupt, though in suspend it may
(later) also be an RTC event. Since actually getting to this
point would be a bug and you can't ever get out again, panic()
on it in the time control code.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Acked-By: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2020-12-13 22:22:37 +01:00
Johannes Berg 3032b94587 um: Simplify IRQ handling code
Reduce dynamic allocations (and thereby cache misses) by simply
embedding the registration data for IRQs in the irq_entry, we
never supported these being really dynamic anyway as only one
was ever allowed ("Trying to reregister ...").

Lockless behaviour is preserved by removing the FD from the poll
set appropriately, but we use reg->events to indicate whether or
not this entry is used, rather than dynamically allocating them.

Also port the list of IRQ entries to list_head instead of the
current open-coded singly-linked list implementation, just for
sanity.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Acked-By: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2020-12-13 22:22:33 +01:00
Johannes Berg 2fccfcc0c7 um: Remove IRQ_NONE type
We don't actually use this in um_request_irq(), so it can
never be assigned. It's also not clear what that would be
useful for, so just remove it.

This results in quite a number of cleanups, all the way to
removing the "SIGIO on close" startup check, since the data
it assigns (pty_close_sigio) is not used anymore.

While at it, also make this an enum so we get a minimum of
type checking, and remove the IRQ_NONE hack in virtio since
we now no longer have the name twice.

Acked-By: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Acked-By: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2020-12-13 22:22:29 +01:00
Johannes Berg 0737402f42 um: irq: Reduce irq_reg allocation
We don't need an array of 4 entries to capture three and the
name 'MAX_IRQ_TYPE' really gets confusing as well. Remove it
and add a correct NUM_IRQ_TYPES, and use that correctly.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Acked-By: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2020-12-13 22:22:23 +01:00
Johannes Berg 458e1f7da0 um: irq: Clean up and rename struct irq_fd
This really shouldn't be called "irq_fd" since it doesn't
carry an fd. Well, it used to, apparently, but that struct
member is unused.

Rename it to "irq_reg" since it more accurately reflects a
registered interrupt, and remove the unused 'next' and 'fd'
members from the struct as well.

While at it, also move it to the implementation, it's not
used anywhere else, and the header file is shared with the
userspace components.

Acked-By: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Acked-By: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2020-12-13 22:22:19 +01:00
Johannes Berg 0ede3c05ee um: Clean up alarm IRQ chip name
We don't use "SIGVTALRM", it's just SIGALRM. Clean up the naming.
While at it, fix the comment's grammar.

Acked-By: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Acked-By: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2020-12-13 22:22:15 +01:00
Johannes Berg 36d46a5907 um: Support dynamic IRQ allocation
It's cumbersome and error-prone to keep adding fixed IRQ numbers,
and for proper device wakeup support for the virtio/vhost-user
support we need to have different IRQs for each device. Even if
in theory two IRQs (with and without wake) might be sufficient,
it's much easier to reason about it when we have dynamic number
assignment. It also makes it easier to add new devices that may
dynamically exist or depending on the configuration, etc.

Add support for this, up to 64 IRQs (the same limit as epoll FDs
we have right now). Since it's not easy to port all the existing
places to dynamic allocation (some data is statically initialized)
keep the low numbers are reserved for the existing hard-coded IRQ
numbers.

Acked-By: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Acked-By: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2020-12-13 22:22:08 +01:00
Johannes Berg ff9632d2a6 um: Fix time-travel mode
Since the time-travel rework, basic time-travel mode hasn't worked
properly, but there's no longer a need for this WARN_ON() so just
remove it and thereby fix things.

Cc: stable@vger.kernel.org
Fixes: 4b786e24ca ("um: time-travel: Rewrite as an event scheduler")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2020-12-13 22:21:46 +01:00
Jens Axboe 09041c92f0 um: Add support for TIF_NOTIFY_SIGNAL
Wire up TIF_NOTIFY_SIGNAL handling for um.

Cc: linux-um@lists.infradead.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Acked-By: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2020-12-13 22:21:02 +01:00
Peter Zijlstra 58c644ba51 sched/idle: Fix arch_cpu_idle() vs tracing
We call arch_cpu_idle() with RCU disabled, but then use
local_irq_{en,dis}able(), which invokes tracing, which relies on RCU.

Switch all arch_cpu_idle() implementations to use
raw_local_irq_{en,dis}able() and carefully manage the
lockdep,rcu,tracing state like we do in entry.

(XXX: we really should change arch_cpu_idle() to not return with
interrupts enabled)

Reported-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lkml.kernel.org/r/20201120114925.594122626@infradead.org
2020-11-24 16:47:35 +01:00
Linus Torvalds bf9a76a470 arch/um: partially revert the conversion to __section() macro
A couple of um files ended up not including the header file that defines
the __section() macro, and the simplest fix is to just revert the change
for those files.

Fixes: 33def8498f treewide: Convert macro and uses of __section(foo) to __section("foo")
Reported-and-tested-by: Guenter Roeck <linux@roeck-us.net>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-26 15:39:37 -07:00
Joe Perches 33def8498f treewide: Convert macro and uses of __section(foo) to __section("foo")
Use a more generic form for __section that requires quotes to avoid
complications with clang and gcc differences.

Remove the quote operator # from compiler_attributes.h __section macro.

Convert all unquoted __section(foo) uses to quoted __section("foo").
Also convert __attribute__((section("foo"))) uses to __section("foo")
even if the __attribute__ has multiple list entry forms.

Conversion done using the script at:

    https://lore.kernel.org/lkml/75393e5ddc272dc7403de74d645e6c6e0f4e70eb.camel@perches.com/2-convert_section.pl

Signed-off-by: Joe Perches <joe@perches.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@gooogle.com>
Reviewed-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-25 14:51:49 -07:00
Linus Torvalds 4a22709e21 arch-cleanup-2020-10-22
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Merge tag 'arch-cleanup-2020-10-22' of git://git.kernel.dk/linux-block

Pull arch task_work cleanups from Jens Axboe:
 "Two cleanups that don't fit other categories:

   - Finally get the task_work_add() cleanup done properly, so we don't
     have random 0/1/false/true/TWA_SIGNAL confusing use cases. Updates
     all callers, and also fixes up the documentation for
     task_work_add().

   - While working on some TIF related changes for 5.11, this
     TIF_NOTIFY_RESUME cleanup fell out of that. Remove some arch
     duplication for how that is handled"

* tag 'arch-cleanup-2020-10-22' of git://git.kernel.dk/linux-block:
  task_work: cleanup notification modes
  tracehook: clear TIF_NOTIFY_RESUME in tracehook_notify_resume()
2020-10-23 10:06:38 -07:00
Linus Torvalds 9453b2d469 This pull request contains the following changes for UML:
- Improve support for non-glibc systems
 - Vector: Add support for scripting and dynamic tap devices
 - Various fixes for the vector networking driver
 - Various fixes for time travel mode
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Merge tag 'for-linus-5.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml

Pull UML updates from Richard Weinberger:

 - Improve support for non-glibc systems

 - Vector: Add support for scripting and dynamic tap devices

 - Various fixes for the vector networking driver

 - Various fixes for time travel mode

* tag 'for-linus-5.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml:
  um: vector: Add dynamic tap interfaces and scripting
  um: Clean up stacktrace dump
  um: Fix incorrect assumptions about max pid length
  um: Remove dead usage of TIF_IA32
  um: Remove redundant NULL check
  um: change sigio_spinlock to a mutex
  um: time-travel: Return the sequence number in ACK messages
  um: time-travel: Fix IRQ handling in time_travel_handle_message()
  um: Allow static linking for non-glibc implementations
  um: Some fixes to build UML with musl
  um: vector: Use GFP_ATOMIC under spin lock
  um: Fix null pointer dereference in vector_user_bpf
2020-10-18 10:03:23 -07:00
Jens Axboe 3c532798ec tracehook: clear TIF_NOTIFY_RESUME in tracehook_notify_resume()
All the callers currently do this, clean it up and move the clearing
into tracehook_notify_resume() instead.

Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-17 15:04:36 -06:00
Linus Torvalds 34eb62d868 Orphan link sections were a long-standing source of obscure bugs,
because the heuristics that various linkers & compilers use to handle them
 (include these bits into the output image vs discarding them silently)
 are both highly idiosyncratic and also version dependent.
 
 Instead of this historically problematic mess, this tree by Kees Cook (et al)
 adds build time asserts and build time warnings if there's any orphan section
 in the kernel or if a section is not sized as expected.
 
 And because we relied on so many silent assumptions in this area, fix a metric
 ton of dependencies and some outright bugs related to this, before we can
 finally enable the checks on the x86, ARM and ARM64 platforms.
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'core-build-2020-10-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull orphan section checking from Ingo Molnar:
 "Orphan link sections were a long-standing source of obscure bugs,
  because the heuristics that various linkers & compilers use to handle
  them (include these bits into the output image vs discarding them
  silently) are both highly idiosyncratic and also version dependent.

  Instead of this historically problematic mess, this tree by Kees Cook
  (et al) adds build time asserts and build time warnings if there's any
  orphan section in the kernel or if a section is not sized as expected.

  And because we relied on so many silent assumptions in this area, fix
  a metric ton of dependencies and some outright bugs related to this,
  before we can finally enable the checks on the x86, ARM and ARM64
  platforms"

* tag 'core-build-2020-10-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (36 commits)
  x86/boot/compressed: Warn on orphan section placement
  x86/build: Warn on orphan section placement
  arm/boot: Warn on orphan section placement
  arm/build: Warn on orphan section placement
  arm64/build: Warn on orphan section placement
  x86/boot/compressed: Add missing debugging sections to output
  x86/boot/compressed: Remove, discard, or assert for unwanted sections
  x86/boot/compressed: Reorganize zero-size section asserts
  x86/build: Add asserts for unwanted sections
  x86/build: Enforce an empty .got.plt section
  x86/asm: Avoid generating unused kprobe sections
  arm/boot: Handle all sections explicitly
  arm/build: Assert for unwanted sections
  arm/build: Add missing sections
  arm/build: Explicitly keep .ARM.attributes sections
  arm/build: Refactor linker script headers
  arm64/build: Assert for unwanted sections
  arm64/build: Add missing DWARF sections
  arm64/build: Use common DISCARDS in linker script
  arm64/build: Remove .eh_frame* sections due to unwind tables
  ...
2020-10-12 13:39:19 -07:00
Johannes Berg 273fe1b676 um: Clean up stacktrace dump
We currently get a few stray newlines, due to the interaction
between printk() and the code here. Remove a few explicit
newline prints to neaten the output.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2020-10-11 23:25:07 +02:00
Johannes Berg f2d05059e1 um: change sigio_spinlock to a mutex
Lockdep complains at boot:

=============================
[ BUG: Invalid wait context ]
5.7.0-05093-g46d91ecd597b #98 Not tainted
-----------------------------
swapper/1 is trying to lock:
0000000060931b98 (&desc[i].request_mutex){+.+.}-{3:3}, at: __setup_irq+0x11d/0x623
other info that might help us debug this:
context-{4:4}
1 lock held by swapper/1:
 #0: 000000006074fed8 (sigio_spinlock){+.+.}-{2:2}, at: sigio_lock+0x1a/0x1c
stack backtrace:
CPU: 0 PID: 1 Comm: swapper Not tainted 5.7.0-05093-g46d91ecd597b #98
Stack:
 7fa4fab0 6028dfd1 0000002a 6008bea5
 7fa50700 7fa50040 7fa4fac0 6028e016
 7fa4fb50 6007f6da 60959c18 00000000
Call Trace:
 [<60023a0e>] show_stack+0x13b/0x155
 [<6028e016>] dump_stack+0x2a/0x2c
 [<6007f6da>] __lock_acquire+0x515/0x15f2
 [<6007eb50>] lock_acquire+0x245/0x273
 [<6050d9f1>] __mutex_lock+0xbd/0x325
 [<6050dc76>] mutex_lock_nested+0x1d/0x1f
 [<6008e27e>] __setup_irq+0x11d/0x623
 [<6008e8ed>] request_threaded_irq+0x169/0x1a6
 [<60021eb0>] um_request_irq+0x1ee/0x24b
 [<600234ee>] write_sigio_irq+0x3b/0x76
 [<600383ca>] sigio_broken+0x146/0x2e4
 [<60020bd8>] do_one_initcall+0xde/0x281

Because we hold sigio_spinlock and then get into requesting
an interrupt with a mutex.

Change the spinlock to a mutex to avoid that.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2020-10-11 23:19:35 +02:00
Johannes Berg d080060913 um: time-travel: Return the sequence number in ACK messages
For external time travel, the protocol says to return the
incoming sequence number in the ACK message to aid debugging,
so do that.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Acked-By: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2020-10-11 23:13:27 +02:00
Johannes Berg ebef8ea2ba um: time-travel: Fix IRQ handling in time_travel_handle_message()
As the comment here indicates, we need to do the polling in the
idle loop without blocking interrupts, since interrupts can be
vhost-user messages that we must process even while in our idle
loop.

I don't know why I explained one thing and implemented another,
but we have indeed observed random hangs due to this, depending
on the timing of the messages.

Fixes: 88ce642492 ("um: Implement time-travel=ext")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Acked-By: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2020-10-11 23:13:20 +02:00
Kees Cook c604abc3f6 vmlinux.lds.h: Split ELF_DETAILS from STABS_DEBUG
The .comment section doesn't belong in STABS_DEBUG. Split it out into a
new macro named ELF_DETAILS. This will gain other non-debug sections
that need to be accounted for when linking with --orphan-handling=warn.

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: linux-arch@vger.kernel.org
Link: https://lore.kernel.org/r/20200821194310.3089815-5-keescook@chromium.org
2020-09-01 09:50:35 +02:00
Gustavo A. R. Silva df561f6688 treewide: Use fallthrough pseudo-keyword
Replace the existing /* fall through */ comments and its variants with
the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary
fall-through markings when it is the case.

[1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
2020-08-23 17:36:59 -05:00
Peter Xu a2beb5f1ef mm: clean up the last pieces of page fault accountings
Here're the last pieces of page fault accounting that were still done
outside handle_mm_fault() where we still have regs==NULL when calling
handle_mm_fault():

arch/powerpc/mm/copro_fault.c:   copro_handle_mm_fault
arch/sparc/mm/fault_32.c:        force_user_fault
arch/um/kernel/trap.c:           handle_page_fault
mm/gup.c:                        faultin_page
                                 fixup_user_fault
mm/hmm.c:                        hmm_vma_fault
mm/ksm.c:                        break_ksm

Some of them has the issue of duplicated accounting for page fault
retries.  Some of them didn't do the accounting at all.

This patch cleans all these up by letting handle_mm_fault() to do per-task
page fault accounting even if regs==NULL (though we'll still skip the perf
event accountings).  With that, we can safely remove all the outliers now.

There's another functional change in that now we account the page faults
to the caller of gup, rather than the task_struct that passed into the gup
code.  More information of this can be found at [1].

After this patch, below things should never be touched again outside
handle_mm_fault():

  - task_struct.[maj|min]_flt
  - PERF_COUNT_SW_PAGE_FAULTS_[MAJ|MIN]

[1] https://lore.kernel.org/lkml/CAHk-=wj_V2Tps2QrMn20_W0OJF9xqNh52XSGA42s-ZJ8Y+GyKw@mail.gmail.com/

Signed-off-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Cain <bcain@codeaurora.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Guo Ren <guoren@kernel.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: James E.J. Bottomley <James.Bottomley@HansenPartnership.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Ley Foon Tan <ley.foon.tan@intel.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Nick Hu <nickhu@andestech.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Rich Felker <dalias@libc.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vincent Chen <deanbo422@gmail.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Will Deacon <will@kernel.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Link: http://lkml.kernel.org/r/20200707225021.200906-25-peterx@redhat.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-12 10:58:04 -07:00
Peter Xu bce617edec mm: do page fault accounting in handle_mm_fault
Patch series "mm: Page fault accounting cleanups", v5.

This is v5 of the pf accounting cleanup series.  It originates from Gerald
Schaefer's report on an issue a week ago regarding to incorrect page fault
accountings for retried page fault after commit 4064b98270 ("mm: allow
VM_FAULT_RETRY for multiple times"):

  https://lore.kernel.org/lkml/20200610174811.44b94525@thinkpad/

What this series did:

  - Correct page fault accounting: we do accounting for a page fault
    (no matter whether it's from #PF handling, or gup, or anything else)
    only with the one that completed the fault.  For example, page fault
    retries should not be counted in page fault counters.  Same to the
    perf events.

  - Unify definition of PERF_COUNT_SW_PAGE_FAULTS: currently this perf
    event is used in an adhoc way across different archs.

    Case (1): for many archs it's done at the entry of a page fault
    handler, so that it will also cover e.g.  errornous faults.

    Case (2): for some other archs, it is only accounted when the page
    fault is resolved successfully.

    Case (3): there're still quite some archs that have not enabled
    this perf event.

    Since this series will touch merely all the archs, we unify this
    perf event to always follow case (1), which is the one that makes most
    sense.  And since we moved the accounting into handle_mm_fault, the
    other two MAJ/MIN perf events are well taken care of naturally.

  - Unify definition of "major faults": the definition of "major
    fault" is slightly changed when used in accounting (not
    VM_FAULT_MAJOR).  More information in patch 1.

  - Always account the page fault onto the one that triggered the page
    fault.  This does not matter much for #PF handlings, but mostly for
    gup.  More information on this in patch 25.

Patchset layout:

Patch 1:     Introduced the accounting in handle_mm_fault(), not enabled.
Patch 2-23:  Enable the new accounting for arch #PF handlers one by one.
Patch 24:    Enable the new accounting for the rest outliers (gup, iommu, etc.)
Patch 25:    Cleanup GUP task_struct pointer since it's not needed any more

This patch (of 25):

This is a preparation patch to move page fault accountings into the
general code in handle_mm_fault().  This includes both the per task
flt_maj/flt_min counters, and the major/minor page fault perf events.  To
do this, the pt_regs pointer is passed into handle_mm_fault().

PERF_COUNT_SW_PAGE_FAULTS should still be kept in per-arch page fault
handlers.

So far, all the pt_regs pointer that passed into handle_mm_fault() is
NULL, which means this patch should have no intented functional change.

Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Cain <bcain@codeaurora.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Guo Ren <guoren@kernel.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: James E.J. Bottomley <James.Bottomley@HansenPartnership.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Ley Foon Tan <ley.foon.tan@intel.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Nick Hu <nickhu@andestech.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Rich Felker <dalias@libc.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vincent Chen <deanbo422@gmail.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Will Deacon <will@kernel.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Link: http://lkml.kernel.org/r/20200707225021.200906-1-peterx@redhat.com
Link: http://lkml.kernel.org/r/20200707225021.200906-2-peterx@redhat.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-12 10:58:02 -07:00
Mike Rapoport f9cb654cb5 asm-generic: pgalloc: provide generic pgd_free()
Most architectures define pgd_free() as a wrapper for free_page().

Provide a generic version in asm-generic/pgalloc.h and enable its use for
most architectures.

Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Pekka Enberg <penberg@kernel.org>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>	[m68k]
Cc: Abdul Haleem <abdhalee@linux.vnet.ibm.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Satheesh Rajendran <sathnaga@linux.vnet.ibm.com>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Matthew Wilcox <willy@infradead.org>
Link: http://lkml.kernel.org/r/20200627143453.31835-7-rppt@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-07 11:33:26 -07:00
Mike Rapoport 1355c31eeb asm-generic: pgalloc: provide generic pmd_alloc_one() and pmd_free_one()
For most architectures that support >2 levels of page tables,
pmd_alloc_one() is a wrapper for __get_free_pages(), sometimes with
__GFP_ZERO and sometimes followed by memset(0) instead.

More elaborate versions on arm64 and x86 account memory for the user page
tables and call to pgtable_pmd_page_ctor() as the part of PMD page
initialization.

Move the arm64 version to include/asm-generic/pgalloc.h and use the
generic version on several architectures.

The pgtable_pmd_page_ctor() is a NOP when ARCH_ENABLE_SPLIT_PMD_PTLOCK is
not enabled, so there is no functional change for most architectures
except of the addition of __GFP_ACCOUNT for allocation of user page
tables.

The pmd_free() is a wrapper for free_page() in all the cases, so no
functional change here.

Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Pekka Enberg <penberg@kernel.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Abdul Haleem <abdhalee@linux.vnet.ibm.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Satheesh Rajendran <sathnaga@linux.vnet.ibm.com>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Link: http://lkml.kernel.org/r/20200627143453.31835-5-rppt@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-07 11:33:26 -07:00
Christian Brauner 714acdbd1c
arch: rename copy_thread_tls() back to copy_thread()
Now that HAVE_COPY_THREAD_TLS has been removed, rename copy_thread_tls()
back simply copy_thread(). It's a simpler name, and doesn't imply that only
tls is copied here. This finishes an outstanding chunk of internal process
creation work since we've added clone3().

Cc: linux-arch@vger.kernel.org
Acked-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>A
Acked-by: Stafford Horne <shorne@gmail.com>
Acked-by: Greentime Hu <green.hu@gmail.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>A
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
2020-07-04 23:41:37 +02:00
Christoph Hellwig fe557319aa maccess: rename probe_kernel_{read,write} to copy_{from,to}_kernel_nofault
Better describe what these functions do.

Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-17 10:57:41 -07:00
Christoph Hellwig 98a23609b1 maccess: always use strict semantics for probe_kernel_read
Except for historical confusion in the kprobes/uprobes and bpf tracers,
which has been fixed now, there is no good reason to ever allow user
memory accesses from probe_kernel_read.  Switch probe_kernel_read to only
read from kernel memory.

[akpm@linux-foundation.org: update it for "mm, dump_page(): do not crash with invalid mapping pointer"]

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20200521152301.2587579-17-hch@lst.de
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-09 09:39:15 -07:00
Christoph Hellwig eab0c6089b maccess: unify the probe kernel arch hooks
Currently architectures have to override every routine that probes
kernel memory, which includes a pure read and strcpy, both in strict
and not strict variants.  Just provide a single arch hooks instead to
make sure all architectures cover all the cases.

[akpm@linux-foundation.org: fix !CONFIG_X86_64 build]

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20200521152301.2587579-11-hch@lst.de
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-09 09:39:15 -07:00
Michel Lespinasse c1e8d7c6a7 mmap locking API: convert mmap_sem comments
Convert comments that reference mmap_sem to reference mmap_lock instead.

[akpm@linux-foundation.org: fix up linux-next leftovers]
[akpm@linux-foundation.org: s/lockaphore/lock/, per Vlastimil]
[akpm@linux-foundation.org: more linux-next fixups, per Michel]

Signed-off-by: Michel Lespinasse <walken@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Davidlohr Bueso <dbueso@suse.de>
Cc: David Rientjes <rientjes@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Laurent Dufour <ldufour@linux.ibm.com>
Cc: Liam Howlett <Liam.Howlett@oracle.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ying Han <yinghan@google.com>
Link: http://lkml.kernel.org/r/20200520052908.204642-13-walken@google.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-09 09:39:14 -07:00
Michel Lespinasse d8ed45c5dc mmap locking API: use coccinelle to convert mmap_sem rwsem call sites
This change converts the existing mmap_sem rwsem calls to use the new mmap
locking API instead.

The change is generated using coccinelle with the following rule:

// spatch --sp-file mmap_lock_api.cocci --in-place --include-headers --dir .

@@
expression mm;
@@
(
-init_rwsem
+mmap_init_lock
|
-down_write
+mmap_write_lock
|
-down_write_killable
+mmap_write_lock_killable
|
-down_write_trylock
+mmap_write_trylock
|
-up_write
+mmap_write_unlock
|
-downgrade_write
+mmap_write_downgrade
|
-down_read
+mmap_read_lock
|
-down_read_killable
+mmap_read_lock_killable
|
-down_read_trylock
+mmap_read_trylock
|
-up_read
+mmap_read_unlock
)
-(&mm->mmap_sem)
+(mm)

Signed-off-by: Michel Lespinasse <walken@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Reviewed-by: Laurent Dufour <ldufour@linux.ibm.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Davidlohr Bueso <dbueso@suse.de>
Cc: David Rientjes <rientjes@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Liam Howlett <Liam.Howlett@oracle.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ying Han <yinghan@google.com>
Link: http://lkml.kernel.org/r/20200520052908.204642-5-walken@google.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-09 09:39:14 -07:00
Mike Rapoport e05c7b1f2b mm: pgtable: add shortcuts for accessing kernel PMD and PTE
The powerpc 32-bit implementation of pgtable has nice shortcuts for
accessing kernel PMD and PTE for a given virtual address.  Make these
helpers available for all architectures.

[rppt@linux.ibm.com: microblaze: fix page table traversal in setup_rt_frame()]
  Link: http://lkml.kernel.org/r/20200518191511.GD1118872@kernel.org
[akpm@linux-foundation.org: s/pmd_ptr_k/pmd_off_k/ in various powerpc places]

Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Cain <bcain@codeaurora.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Greg Ungerer <gerg@linux-m68k.org>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Guo Ren <guoren@kernel.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Ley Foon Tan <ley.foon.tan@intel.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Nick Hu <nickhu@andestech.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Rich Felker <dalias@libc.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vincent Chen <deanbo422@gmail.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Will Deacon <will@kernel.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Link: http://lkml.kernel.org/r/20200514170327.31389-9-rppt@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-09 09:39:13 -07:00
Mike Rapoport e31cf2f4ca mm: don't include asm/pgtable.h if linux/mm.h is already included
Patch series "mm: consolidate definitions of page table accessors", v2.

The low level page table accessors (pXY_index(), pXY_offset()) are
duplicated across all architectures and sometimes more than once.  For
instance, we have 31 definition of pgd_offset() for 25 supported
architectures.

Most of these definitions are actually identical and typically it boils
down to, e.g.

static inline unsigned long pmd_index(unsigned long address)
{
        return (address >> PMD_SHIFT) & (PTRS_PER_PMD - 1);
}

static inline pmd_t *pmd_offset(pud_t *pud, unsigned long address)
{
        return (pmd_t *)pud_page_vaddr(*pud) + pmd_index(address);
}

These definitions can be shared among 90% of the arches provided
XYZ_SHIFT, PTRS_PER_XYZ and xyz_page_vaddr() are defined.

For architectures that really need a custom version there is always
possibility to override the generic version with the usual ifdefs magic.

These patches introduce include/linux/pgtable.h that replaces
include/asm-generic/pgtable.h and add the definitions of the page table
accessors to the new header.

This patch (of 12):

The linux/mm.h header includes <asm/pgtable.h> to allow inlining of the
functions involving page table manipulations, e.g.  pte_alloc() and
pmd_alloc().  So, there is no point to explicitly include <asm/pgtable.h>
in the files that include <linux/mm.h>.

The include statements in such cases are remove with a simple loop:

	for f in $(git grep -l "include <linux/mm.h>") ; do
		sed -i -e '/include <asm\/pgtable.h>/ d' $f
	done

Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Cain <bcain@codeaurora.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Greg Ungerer <gerg@linux-m68k.org>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Guo Ren <guoren@kernel.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Ley Foon Tan <ley.foon.tan@intel.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Nick Hu <nickhu@andestech.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Rich Felker <dalias@libc.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vincent Chen <deanbo422@gmail.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Will Deacon <will@kernel.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Link: http://lkml.kernel.org/r/20200514170327.31389-1-rppt@kernel.org
Link: http://lkml.kernel.org/r/20200514170327.31389-2-rppt@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-09 09:39:13 -07:00
Dmitry Safonov 9cb8f069de kernel: rename show_stack_loglvl() => show_stack()
Now the last users of show_stack() got converted to use an explicit log
level, show_stack_loglvl() can drop it's redundant suffix and become once
again well known show_stack().

Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/20200418201944.482088-51-dima@arista.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-09 09:39:13 -07:00
Dmitry Safonov 1ad87824f4 um: add show_stack_loglvl()
Currently, the log-level of show_stack() depends on a platform
realization.  It creates situations where the headers are printed with
lower log level or higher than the stacktrace (depending on a platform or
user).

Furthermore, it forces the logic decision from user to an architecture
side.  In result, some users as sysrq/kdb/etc are doing tricks with
temporary rising console_loglevel while printing their messages.  And in
result it not only may print unwanted messages from other CPUs, but also
omit printing at all in the unlucky case where the printk() was deferred.

Introducing log-level parameter and KERN_UNSUPPRESSED [1] seems an easier
approach than introducing more printk buffers.  Also, it will consolidate
printings with headers.

Introduce show_stack_loglvl(), that eventually will substitute
show_stack().

[1]: https://lore.kernel.org/lkml/20190528002412.1625-1-dima@arista.com/T/#u

Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
Link: http://lkml.kernel.org/r/20200418201944.482088-37-dima@arista.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-09 09:39:12 -07:00
Dmitry Safonov 3dd923f39a um/sysrq: remove needless variable sp
`sp' is a needless excercise here.

Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
Link: http://lkml.kernel.org/r/20200418201944.482088-36-dima@arista.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-09 09:39:12 -07:00
Linus Torvalds 9fb4c5250f Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/livepatching/livepatching
Pull livepatching updates from Jiri Kosina:

 - simplifications and improvements for issues Peter Ziljstra found
   during his previous work on W^X cleanups.

   This allows us to remove livepatch arch-specific .klp.arch sections
   and add proper support for jump labels in patched code.

   Also, this patchset removes the last module_disable_ro() usage in the
   tree.

   Patches from Josh Poimboeuf and Peter Zijlstra

 - a few other minor cleanups

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/livepatching/livepatching:
  MAINTAINERS: add lib/livepatch to LIVE PATCHING
  livepatch: add arch-specific headers to MAINTAINERS
  livepatch: Make klp_apply_object_relocs static
  MAINTAINERS: adjust to livepatch .klp.arch removal
  module: Make module_enable_ro() static again
  x86/module: Use text_mutex in apply_relocate_add()
  module: Remove module_disable_ro()
  livepatch: Remove module_disable_ro() usage
  x86/module: Use text_poke() for late relocations
  s390/module: Use s390_kernel_write() for late relocations
  s390: Change s390_kernel_write() return type to match memcpy()
  livepatch: Prevent module-specific KLP rela sections from referencing vmlinux symbols
  livepatch: Remove .klp.arch
  livepatch: Apply vmlinux-specific KLP relocations early
  livepatch: Disallow vmlinux.ko
2020-06-04 11:13:03 -07:00
Mike Rapoport fa3354e4ea mm: free_area_init: use maximal zone PFNs rather than zone sizes
Currently, architectures that use free_area_init() to initialize memory
map and node and zone structures need to calculate zone and hole sizes.
We can use free_area_init_nodes() instead and let it detect the zone
boundaries while the architectures will only have to supply the possible
limits for the zones.

Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tested-by: Hoan Tran <hoan@os.amperecomputing.com>	[arm64]
Reviewed-by: Baoquan He <bhe@redhat.com>
Cc: Brian Cain <bcain@codeaurora.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Greg Ungerer <gerg@linux-m68k.org>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Guo Ren <guoren@kernel.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Ley Foon Tan <ley.foon.tan@intel.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Nick Hu <nickhu@andestech.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Rich Felker <dalias@libc.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Link: http://lkml.kernel.org/r/20200412194859.12663-5-rppt@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-03 20:09:43 -07:00
Peter Zijlstra 88fc078a7a x86/module: Use text_poke() for late relocations
Because of late module patching, a livepatch module needs to be able to
apply some of its relocations well after it has been loaded.  Instead of
playing games with module_{dis,en}able_ro(), use existing text poking
mechanisms to apply relocations after module loading.

So far only x86, s390 and Power have HAVE_LIVEPATCH but only the first
two also have STRICT_MODULE_RWX.

This will allow removal of the last module_disable_ro() usage in
livepatch.  The ultimate goal is to completely disallow making
executable mappings writable.

[ jpoimboe: Split up patches.  Use mod state to determine whether
	    memcpy() can be used.  Implement text_poke() for UML. ]

Cc: x86@kernel.org
Suggested-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Joe Lawrence <joe.lawrence@redhat.com>
Acked-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2020-05-08 00:12:43 +02:00
Johannes Berg e6da5df0ee um: syscall.c: include <asm/unistd.h>
Without CONFIG_SECCOMP, we don't get this include recursively
through the existing includes, thus failing the build on not
having __NR_syscall_max defined. Add the necessary include to
fix this.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Acked-By: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2020-04-29 21:22:04 +02:00
Linus Torvalds 762a9f2f01 This pull request contains the following changes for UML:
- New mode for time travel, external via virtio
 - Fixes for ubd to make sure no requests can get lost
 - Fixes for vector networking
 - Allow CONFIG_STATIC_LINK only when possible
 - Minor cleanups and fixes
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Merge tag 'for-linus-5.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml

Pull UML updates from Richard Weinberger:

 - New mode for time travel, external via virtio

 - Fixes for ubd to make sure no requests can get lost

 - Fixes for vector networking

 - Allow CONFIG_STATIC_LINK only when possible

 - Minor cleanups and fixes

* tag 'for-linus-5.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml:
  um: Remove some unnecessary NULL checks in vector_user.c
  um: vector: Avoid NULL ptr deference if transport is unset
  um: Make CONFIG_STATIC_LINK actually static
  um: Implement cpu_relax() as ndelay(1) for time-travel
  um: Implement ndelay/udelay in time-travel mode
  um: Implement time-travel=ext
  um: virtio: Implement VHOST_USER_PROTOCOL_F_INBAND_NOTIFICATIONS
  um: time-travel: Rewrite as an event scheduler
  um: Move timer-internal.h to non-shared
  hostfs: Use kasprintf() instead of fixed buffer formatting
  um: falloc.h needs to be directly included for older libc
  um: ubd: Retry buffer read on any kind of error
  um: ubd: Prevent buffer overrun on command completion
  um: Fix overlapping ELF segments when statically linked
  um: Delete never executed timer
  um: Don't overwrite ethtool driver version
  um: Fix len of file in create_pid_file
  um: Don't use console_drivers directly
  um: Cleanup CONFIG_IOSCHED_CFQ
2020-04-07 12:36:09 -07:00
Peter Xu 4064b98270 mm: allow VM_FAULT_RETRY for multiple times
The idea comes from a discussion between Linus and Andrea [1].

Before this patch we only allow a page fault to retry once.  We achieved
this by clearing the FAULT_FLAG_ALLOW_RETRY flag when doing
handle_mm_fault() the second time.  This was majorly used to avoid
unexpected starvation of the system by looping over forever to handle the
page fault on a single page.  However that should hardly happen, and after
all for each code path to return a VM_FAULT_RETRY we'll first wait for a
condition (during which time we should possibly yield the cpu) to happen
before VM_FAULT_RETRY is really returned.

This patch removes the restriction by keeping the FAULT_FLAG_ALLOW_RETRY
flag when we receive VM_FAULT_RETRY.  It means that the page fault handler
now can retry the page fault for multiple times if necessary without the
need to generate another page fault event.  Meanwhile we still keep the
FAULT_FLAG_TRIED flag so page fault handler can still identify whether a
page fault is the first attempt or not.

Then we'll have these combinations of fault flags (only considering
ALLOW_RETRY flag and TRIED flag):

  - ALLOW_RETRY and !TRIED:  this means the page fault allows to
                             retry, and this is the first try

  - ALLOW_RETRY and TRIED:   this means the page fault allows to
                             retry, and this is not the first try

  - !ALLOW_RETRY and !TRIED: this means the page fault does not allow
                             to retry at all

  - !ALLOW_RETRY and TRIED:  this is forbidden and should never be used

In existing code we have multiple places that has taken special care of
the first condition above by checking against (fault_flags &
FAULT_FLAG_ALLOW_RETRY).  This patch introduces a simple helper to detect
the first retry of a page fault by checking against both (fault_flags &
FAULT_FLAG_ALLOW_RETRY) and !(fault_flag & FAULT_FLAG_TRIED) because now
even the 2nd try will have the ALLOW_RETRY set, then use that helper in
all existing special paths.  One example is in __lock_page_or_retry(), now
we'll drop the mmap_sem only in the first attempt of page fault and we'll
keep it in follow up retries, so old locking behavior will be retained.

This will be a nice enhancement for current code [2] at the same time a
supporting material for the future userfaultfd-writeprotect work, since in
that work there will always be an explicit userfault writeprotect retry
for protected pages, and if that cannot resolve the page fault (e.g., when
userfaultfd-writeprotect is used in conjunction with swapped pages) then
we'll possibly need a 3rd retry of the page fault.  It might also benefit
other potential users who will have similar requirement like userfault
write-protection.

GUP code is not touched yet and will be covered in follow up patch.

Please read the thread below for more information.

[1] https://lore.kernel.org/lkml/20171102193644.GB22686@redhat.com/
[2] https://lore.kernel.org/lkml/20181230154648.GB9832@redhat.com/

Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Suggested-by: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tested-by: Brian Geffon <bgeffon@google.com>
Cc: Bobby Powers <bobbypowers@gmail.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Denis Plotnikov <dplotnikov@virtuozzo.com>
Cc: "Dr . David Alan Gilbert" <dgilbert@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: "Kirill A . Shutemov" <kirill@shutemov.name>
Cc: Martin Cracauer <cracauer@cons.org>
Cc: Marty McFadden <mcfadden8@llnl.gov>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Maya Gokhale <gokhale2@llnl.gov>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Link: http://lkml.kernel.org/r/20200220160246.9790-1-peterx@redhat.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-04-02 09:35:30 -07:00
Peter Xu dde1607248 mm: introduce FAULT_FLAG_DEFAULT
Although there're tons of arch-specific page fault handlers, most of them
are still sharing the same initial value of the page fault flags.  Say,
merely all of the page fault handlers would allow the fault to be retried,
and they also allow the fault to respond to SIGKILL.

Let's define a default value for the fault flags to replace those initial
page fault flags that were copied over.  With this, it'll be far easier to
introduce new fault flag that can be used by all the architectures instead
of touching all the archs.

Signed-off-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tested-by: Brian Geffon <bgeffon@google.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Bobby Powers <bobbypowers@gmail.com>
Cc: Denis Plotnikov <dplotnikov@virtuozzo.com>
Cc: "Dr . David Alan Gilbert" <dgilbert@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: "Kirill A . Shutemov" <kirill@shutemov.name>
Cc: Martin Cracauer <cracauer@cons.org>
Cc: Marty McFadden <mcfadden8@llnl.gov>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Maya Gokhale <gokhale2@llnl.gov>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Link: http://lkml.kernel.org/r/20200220160238.9694-1-peterx@redhat.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-04-02 09:35:29 -07:00
Johannes Berg 0bc8fb4dda um: Implement ndelay/udelay in time-travel mode
In external or inf-cpu time-travel mode, ndelay/udelay currently
just waste CPU time since the simulation time doesn't advance.
Implement them properly in this case.

Note that the "if (time_travel_mode == ...)" parts compile out
if CONFIG_UML_TIME_TRAVEL_SUPPORT isn't set, time_travel_mode is
defined to TT_MODE_OFF in that case.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2020-03-29 23:29:52 +02:00
Johannes Berg 88ce642492 um: Implement time-travel=ext
This implements synchronized time-travel mode which - using a special
application on a unix socket - lets multiple machines take part in a
time-travelling simulation together.

The protocol for the unix domain socket is defined in the new file
include/uapi/linux/um_timetravel.h.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2020-03-29 23:29:08 +02:00
Johannes Berg 4b786e24ca um: time-travel: Rewrite as an event scheduler
Instead of tracking all the various timer configurations,
modify the time-travel mode to have an event scheduler and
use a timer event on the scheduler to handle the different
timer configurations.

This doesn't change the function right now, but it prepares
the code for having different kinds of events in the future
(i.e. interrupts coming from other devices that are part of
co-simulation.)

While at it, also move time_travel_sleep() to time.c to
reduce the externally visible API surface.

Also, we really should mark time-travel as incompatible with
SMP, even if UML doesn't support SMP yet.

Finally, I noticed a bug while developing this - if we move
time forward due to consuming time while reading the clock,
we might move across the next event and that would cause us
to go backward in time when we then handle that event. Fix
that by invoking the whole event machine in this case, but
in order to simplify this, make reading the clock only cost
something when interrupts are not disabled. Otherwise, we'd
have to hook into the interrupt delivery machinery etc. and
that's somewhat intrusive.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2020-03-29 23:28:51 +02:00
Johannes Berg f185063bff um: Move timer-internal.h to non-shared
This file isn't really shared, it's only used on the kernel side,
not on the user side. Remove the include from the user-side and
move the file to a better place.

While at it, rename it to time-internal.h, it's not really just
timers but all kinds of things related to timekeeping.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2020-03-29 23:28:43 +02:00
David Gow 598f563036 um: Fix overlapping ELF segments when statically linked
When statically linked, the .text section in UML kernels is not page
aligned, causing it to share a page with the executable headers. As
.text and the executable headers have different permissions, this causes
the kernel to wish to map the same page twice (once as headers with r--
permissions, once as .text with r-x permissions), causing a segfault,
and a nasty message printed to the host kernel's dmesg:

"Uhuuh, elf segment at 0000000060000000 requested but the memory is
mapped already"

By aligning the .text to a page boundary (as in the dynamically linked
version in dyn.lds.S), there is no such overlap, and the kernel runs
correctly.

Signed-off-by: David Gow <davidgow@google.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2020-03-29 23:21:29 +02:00
Andy Shevchenko 7d7c056828 um: Don't use console_drivers directly
console_drivers is kind of (semi-)private variable to the console code.
Direct use of it make us stuck with it being exported here and there.
Reduce use of console_drivers by replacing it with for_each_console().

Cc: Thomas Meyer <thomas@m3y3r.de>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2020-03-29 23:17:10 +02:00
Alexey Dobriyan 97a32539b9 proc: convert everything to "struct proc_ops"
The most notable change is DEFINE_SHOW_ATTRIBUTE macro split in
seq_file.h.

Conversion rule is:

	llseek		=> proc_lseek
	unlocked_ioctl	=> proc_ioctl

	xxx		=> proc_xxx

	delete ".owner = THIS_MODULE" line

[akpm@linux-foundation.org: fix drivers/isdn/capi/kcapi_proc.c]
[sfr@canb.auug.org.au: fix kernel/sched/psi.c]
  Link: http://lkml.kernel.org/r/20200122180545.36222f50@canb.auug.org.au
Link: http://lkml.kernel.org/r/20191225172546.GB13378@avx2
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-02-04 03:05:26 +00:00
Johannes Berg 87c9366e17 Revert "um: Enable CONFIG_CONSTRUCTORS"
This reverts commit 786b2384bf ("um: Enable CONFIG_CONSTRUCTORS").

There are two issues with this commit, uncovered by Anton in tests
on some (Debian) systems:

1) I completely forgot to call any constructors if CONFIG_CONSTRUCTORS
   isn't set. Don't recall now if it just wasn't needed on my system, or
   if I never tested this case.

2) With that fixed, it works - with CONFIG_CONSTRUCTORS *unset*. If I
   set CONFIG_CONSTRUCTORS, it fails again, which isn't totally
   unexpected since whatever wanted to run is likely to have to run
   before the kernel init etc. that calls the constructors in this case.

Basically, some constructors that gcc emits (libc has?) need to run
very early during init; the failure mode otherwise was that the ptrace
fork test already failed:

----------------------
$ ./linux mem=512M
Core dump limits :
	soft - 0
	hard - NONE
Checking that ptrace can change system call numbers...check_ptrace : child exited with exitcode 6, while expecting 0; status 0x67f
Aborted
----------------------

Thinking more about this, it's clear that we simply cannot support
CONFIG_CONSTRUCTORS in UML. All the cases we need now (gcov, kasan)
involve not use of the __attribute__((constructor)), but instead
some constructor code/entry generated by gcc. Therefore, we cannot
distinguish between kernel constructors and system constructors.

Thus, revert this commit.

Cc: stable@vger.kernel.org [5.4+]
Fixes: 786b2384bf ("um: Enable CONFIG_CONSTRUCTORS")
Reported-by: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Acked-by: Anton Ivanov <anton.ivanov@cambridgegreys.co.uk>

Signed-off-by: Richard Weinberger <richard@nod.at>
2020-01-19 22:42:06 +01:00
Amanieu d'Antras 457677c70c
um: Implement copy_thread_tls
This is required for clone3 which passes the TLS value through a
struct rather than a register.

Signed-off-by: Amanieu d'Antras <amanieu@gmail.com>
Cc: linux-um@lists.infradead.org
Cc: <stable@vger.kernel.org> # 5.3.x
Link: https://lore.kernel.org/r/20200104123928.1048822-1-amanieu@gmail.com
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
2020-01-07 13:31:29 +01:00
Mike Rapoport e19f97ed67 um: add support for folded p4d page tables
The UML port uses 4 and 5 level fixups to support higher level page
table directories in the generic VM code.

Implement primitives necessary for the 4th level folding, add walks of
p4d level where appropriate and drop usage of __ARCH_USE_5LEVEL_HACK.

Link: http://lkml.kernel.org/r/1572938135-31886-13-git-send-email-rppt@kernel.org
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Cc: Anatoly Pugachev <matorola@gmail.com>
Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Greg Ungerer <gerg@linux-m68k.org>
Cc: Helge Deller <deller@gmx.de>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Mark Salter <msalter@redhat.com>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Peter Rosin <peda@axentia.se>
Cc: Richard Weinberger <richard@nod.at>
Cc: Rolf Eike Beer <eike-kernel@sf-tec.de>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Russell King <rmk+kernel@armlinux.org.uk>
Cc: Sam Creasey <sammy@sammy.net>
Cc: Vincent Chen <deanbo422@gmail.com>
Cc: Vineet Gupta <Vineet.Gupta1@synopsys.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-12-04 19:44:15 -08:00
Mike Rapoport 4e65e76f1e um: remove unused pxx_offset_proc() and addr_pte() functions
The pxx_offset_proc() and addr_pte() functions are never used.  Remove
them.

Link: http://lkml.kernel.org/r/1572938135-31886-12-git-send-email-rppt@kernel.org
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Acked-by: Richard Weinberger <richard@nod.at>
Cc: Anatoly Pugachev <matorola@gmail.com>
Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Greg Ungerer <gerg@linux-m68k.org>
Cc: Helge Deller <deller@gmx.de>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Mark Salter <msalter@redhat.com>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Peter Rosin <peda@axentia.se>
Cc: Rolf Eike Beer <eike-kernel@sf-tec.de>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Russell King <rmk+kernel@armlinux.org.uk>
Cc: Sam Creasey <sammy@sammy.net>
Cc: Vincent Chen <deanbo422@gmail.com>
Cc: Vineet Gupta <Vineet.Gupta1@synopsys.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-12-04 19:44:15 -08:00
Christian Brauner fefad9ef58 seccomp: simplify secure_computing()
Afaict, the struct seccomp_data argument to secure_computing() is unused
by all current callers. So let's remove it.
The argument was added in [1]. It was added because having the arch
supply the syscall arguments used to be faster than having it done by
secure_computing() (cf. Andy's comment in [2]). This is not true anymore
though.

/* References */
[1]: 2f275de5d1 ("seccomp: Add a seccomp_data parameter secure_computing()")
[2]: https://lore.kernel.org/r/CALCETrU_fs_At-hTpr231kpaAd0z7xJN4ku-DvzhRU6cvcJA_w@mail.gmail.com

Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Drewry <wad@chromium.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-parisc@vger.kernel.org
Cc: linux-s390@vger.kernel.org
Cc: linux-um@lists.infradead.org
Cc: x86@kernel.org
Acked-by: Borislav Petkov <bp@suse.de>
Acked-by: Andy Lutomirski <luto@kernel.org>
Link: https://lore.kernel.org/r/20190924064420.6353-1-christian.brauner@ubuntu.com
Signed-off-by: Kees Cook <keescook@chromium.org>
2019-10-10 14:55:24 -07:00
Erel Geron 73625ed663 um: irq: Fix LAST_IRQ usage in init_IRQ()
LAST_IRQ was used incorrectly in init_IRQ.
Commit 09ccf0364c forgot to update the for loop.
Fix this.

Fixes: 49da7e64f3 ("High Performance UML Vector Network Driver")
Fixes: 09ccf0364c ("um: Fix off by one error in IRQ enumeration")
Signed-off-by: Erel Geron <erelx.geron@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Acked-by: Anton Ivanov <anton.ivanov@cambridgegreys.co.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>
2019-09-16 08:38:58 +02:00
Alex Dewar 0d1fb0a47c um: Add SPDX headers to files in arch/um/kernel/
Convert files to use SPDX header. All files are licensed under the
GPLv2.

Signed-off-by: Alex Dewar <alex.dewar@gmx.co.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>
2019-09-15 21:37:17 +02:00
Erel Geron 5d38f32499 um: drivers: Add virtio vhost-user driver
This module allows virtio devices to be used over a vhost-user socket.

Signed-off-by: Erel Geron <erelx.geron@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2019-09-15 21:37:15 +02:00
Johannes Berg 278911ee89 um: time-travel: Restrict time update in IRQ handler
We currently do the time updates in the timer handler, even if
we just call the timer handler ourselves. In basic mode we must
in fact do it there since otherwise the OS timer signal won't
move time forward, but in inf-cpu mode we don't need to, and
it's harder to understand.

Restrict the update there to basic mode, adding a comment, and
do it before calling the timer_handler() in inf-cpu mode.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2019-09-15 21:37:13 +02:00
Johannes Berg eec94b8acb um: time-travel: Fix periodic timers
Periodic timers are broken, because the also only fire once.
As it happens, Linux doesn't care because it only sets the
timer to periodic very briefly during boot, and then switches
it only between one-shot and off later.

Nevertheless, fix the logic (we shouldn't even be looking at
time_travel_timer_expiry unless the timer is enabled) and
change the code to fire the timer periodically in periodic
mode, in case it ever gets used in the future.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2019-09-15 21:37:13 +02:00
Johannes Berg 786b2384bf um: Enable CONFIG_CONSTRUCTORS
We do need to call the constructors for *modules*, and
at least for KASAN in the future, we must call even the
kernel constructors only later when the kernel has been
initialized.

Instead of relying on libc to call them, emit an empty
section for libc and let the kernel's CONSTRUCTORS code
do the rest of the job.

Tested that it indeed doesn't work in modules, and does
work after the fixes in both, with a few functions with
__attribute__((constructor)) in both dynamic and static
builds.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2019-09-15 21:37:13 +02:00
Johannes Berg 324f80cc3e um: Place (soft)irq text with macros
Otherwise it gets placed without the start/end markers.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2019-09-15 21:37:12 +02:00
Johannes Berg 0dafcbe128 um: Implement TRACE_IRQFLAGS_SUPPORT
UML enables TRACE_IRQFLAGS_SUPPORT but doesn't actually implement
it. It seems to have been added for lockdep support, but that can't
actually really work well without IRQ flags tracing, as is also
very noisily reported when enabling CONFIG_DEBUG_LOCKDEP.

Implement it now.

Fixes: 711553efa5 ("[PATCH] uml: declare in Kconfig our partial LOCKDEP support")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2019-09-15 21:37:11 +02:00
Masahiro Yamada 03e46a4d5b um: Remove meaningless clearing of clean-files
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2019-09-15 21:37:08 +02:00
Johannes Berg e0917f8795 um: fix time travel mode
Unfortunately, my build fix for when time travel mode isn't
enabled broke time travel mode, because I forgot that we need
to use the timer time after the timer has been marked disabled,
and thus need to leave the time stored instead of zeroing it.

Fix that by splitting the inline into two, so we can call only
the _mode() one in the relevant code path.

Fixes: b482e48d29 ("um: fix build without CONFIG_UML_TIME_TRAVEL_SUPPORT")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2019-08-23 00:39:53 +02:00
Linus Torvalds f2772a0e48 This pull request contains the following changes for UML:
- A new timer mode, time travel, for testing with UML
 - Many bugixes/improvements for the serial line driver
 - Various bugfixes
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Merge tag 'for-linus-5.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml

Pull UML updates from Richard Weinberger:

 - A new timer mode, time travel, for testing with UML

 - Many bugixes/improvements for the serial line driver

 - Various bugfixes

* tag 'for-linus-5.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml:
  um: fix build without CONFIG_UML_TIME_TRAVEL_SUPPORT
  um: Fix kcov crash during startup
  um: configs: Remove useless UEVENT_HELPER_PATH
  um: Support time travel mode
  um: Pass nsecs to os timer functions
  um: Remove drivers/ssl.h
  um: Don't garbage collect in deactivate_all_fds()
  um: Silence lockdep complaint about mmap_sem
  um: Remove locking in deactivate_all_fds()
  um: Timer code cleanup
  um: fix os_timer_one_shot()
  um: Fix IRQ controller regression on console read
2019-07-14 17:17:34 -07:00
Mike Rapoport f32848e169 um: switch to generic version of pte allocation
um allocates PTE pages with __get_free_page() and uses
GFP_KERNEL | __GFP_ZERO for the allocations.

Switch it to the generic version that does exactly the same thing for the
kernel page tables and adds __GFP_ACCOUNT for the user PTEs.

The pte_free() and pte_free_kernel() versions are identical to the generic
ones and can be simply dropped.

Link: http://lkml.kernel.org/r/1557296232-15361-14-git-send-email-rppt@linux.ibm.com
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Reviewed-by: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Acked-by: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Guo Ren <guoren@kernel.org>
Cc: Guo Ren <ren_guo@c-sky.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Ley Foon Tan <lftan@altera.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Palmer Dabbelt <palmer@sifive.com>
Cc: Paul Burton <paul.burton@mips.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Richard Kuo <rkuo@codeaurora.org>
Cc: Richard Weinberger <richard@nod.at>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Sam Creasey <sammy@sammy.net>
Cc: Vincent Chen <deanbo422@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-07-12 11:05:45 -07:00
Linus Torvalds 5ad18b2e60 Merge branch 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
Pull force_sig() argument change from Eric Biederman:
 "A source of error over the years has been that force_sig has taken a
  task parameter when it is only safe to use force_sig with the current
  task.

  The force_sig function is built for delivering synchronous signals
  such as SIGSEGV where the userspace application caused a synchronous
  fault (such as a page fault) and the kernel responded with a signal.

  Because the name force_sig does not make this clear, and because the
  force_sig takes a task parameter the function force_sig has been
  abused for sending other kinds of signals over the years. Slowly those
  have been fixed when the oopses have been tracked down.

  This set of changes fixes the remaining abusers of force_sig and
  carefully rips out the task parameter from force_sig and friends
  making this kind of error almost impossible in the future"

* 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (27 commits)
  signal/x86: Move tsk inside of CONFIG_MEMORY_FAILURE in do_sigbus
  signal: Remove the signal number and task parameters from force_sig_info
  signal: Factor force_sig_info_to_task out of force_sig_info
  signal: Generate the siginfo in force_sig
  signal: Move the computation of force into send_signal and correct it.
  signal: Properly set TRACE_SIGNAL_LOSE_INFO in __send_signal
  signal: Remove the task parameter from force_sig_fault
  signal: Use force_sig_fault_to_task for the two calls that don't deliver to current
  signal: Explicitly call force_sig_fault on current
  signal/unicore32: Remove tsk parameter from __do_user_fault
  signal/arm: Remove tsk parameter from __do_user_fault
  signal/arm: Remove tsk parameter from ptrace_break
  signal/nds32: Remove tsk parameter from send_sigtrap
  signal/riscv: Remove tsk parameter from do_trap
  signal/sh: Remove tsk parameter from force_sig_info_fault
  signal/um: Remove task parameter from send_sigtrap
  signal/x86: Remove task parameter from send_sigtrap
  signal: Remove task parameter from force_sig_mceerr
  signal: Remove task parameter from force_sig
  signal: Remove task parameter from force_sigsegv
  ...
2019-07-08 21:48:15 -07:00