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>
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>
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>
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>
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>
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>
`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>
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
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>
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>
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>
- 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
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
- 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
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>
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
...
When CONFIG_UML_TIME_TRAVEL_SUPPORT isn't set, the build was broken.
Fix this.
Fixes: 065038706f ("um: Support time travel mode")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Kcov fails to start when compiled with kcov. Disable KCOV on
arch/uml/kernel/skas.
$ gdb -q -ex r ./vmlinux
Program received signal SIGSEGV, Segmentation fault.
check_kcov_mode (t=<>, needed_mode=<>) at kernel/kcov.c:70
70 mode = READ_ONCE(t->kcov_mode);
Signed-off-by: Marek Majkowski <marek@cloudflare.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Sometimes it can be useful to run with "time travel" inside the
UML instance, for example for testing. For example, some tests
for the wireless subsystem and userspace are based on hwsim, a
virtual wireless adapter. Some tests can take a long time to
run because they e.g. wait for 120 seconds to elapse for some
regulatory checks. This obviously goes faster if it need not
actually wait that long, but time inside the test environment
just "bumps up" when there's nothing to do.
Add CONFIG_UML_TIME_TRAVEL_SUPPORT to enable code to support
such modes at runtime, selected on the command line:
* just "time-travel", in which time inside the UML instance
can move faster than real time, if there's nothing to do
* "time-travel=inf-cpu" in which time also moves slower and
any CPU processing takes no time at all, which allows to
implement consistent behaviour regardless of host CPU load
(or speed) or debug overhead.
An additional "time-travel-start=<seconds>" parameter is also
supported in this case to start the wall clock at this time
(in unix epoch).
With this enabled, the test mentioned above goes from a runtime
of about 140 seconds (with startup overhead and all) to being
CPU bound and finishing in 15 seconds (on my slow laptop).
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
This makes the code clearer and lets the time travel patch have
the actual time used for these functions in just one place.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
My previous commit didn't actually address the whole issue with
lockdep shutdown, I had another local modification that disabled
lockdep but that wasn't sufficient alone, so had to do the other
change.
Another issue remained though - during kfree() we acquire locks
and lockdep tries to annotate those with exactly the same issue
in the other patch - we no longer have "current".
So, just remove the garbage collection. There's no value in it
anyway since we're going to shut down anyway and marking a slab
object as free is now not very useful anymore.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Not only does the locking contradict the comment, and as
the comment says is pointless and actually harmful (all
the actual OS threads have exited already), but it also
causes crashes when lockdep is enabled, because calling
into the spinlock calls into lockdep, which then tries
to determine the current task, which no longer exists.
Remove the locking to let UML shut down cleanly in case
lockdep is enabled.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
There are some unused functions, and some others that have
unused arguments; clean up the timer code a bit.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
The conversion of UML to use epoll based IRQ controller claimed that
clone_one_chan() can safely call um_free_irq() while starting to ignore
the delay_free_irq parameter that explicitly noted that the IRQ cannot
be freed because this is being called from chan_interrupt(). This
resulted in free_irq() getting called in interrupt context ("Trying to
free IRQ 6 from IRQ context!").
Fix this by restoring previously used delay_free_irq processing.
Fixes: ff6a17989c ("Epoll based IRQ controller")
Signed-off-by: Jouni Malinen <j@w1.fi>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Christoph Hellwig
Michel Lespinasse
Mike Rapoport
Dmitry Safonov
Linus Torvalds
Peter Zijlstra
Johannes Berg
Peter Xu
David Gow
Andy Shevchenko
Alexey Dobriyan
Amanieu d'Antras
Christian Brauner
Erel Geron
Alex Dewar
Masahiro Yamada
Marek Majkowski
Jouni Malinen