This patch fixes a crash caused by an interrupt coming in when an IRQ stack
is being torn down. When this happens, handle_signal will loop, setting up
the IRQ stack again because the tearing down had finished, and handling
whatever signals had come in.
However, to_irq_stack returns a mask of pending signals to be handled, plus
bit zero is set if the IRQ stack was already active, and thus shouldn't be
torn down. This causes a problem because when handle_signal goes around
the loop, sig will be zero, and to_irq_stack will duly set bit zero in the
returned mask, faking handle_signal into believing that it shouldn't tear
down the IRQ stack and return thread_info pointers back to their original
values.
This will eventually cause a crash, as the IRQ stack thread_info will
continue pointing to the original task_struct and an interrupt will look
into it after it has been freed.
The fix is to stop passing a signal number into to_irq_stack. Rather, the
pending signals mask is initialized beforehand with the bit for sig already
set. References to sig in to_irq_stack can be replaced with references to
the mask.
[akpm@linux-foundation.org: use UL]
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
I found a type mismatch in UML that makes host block devices unusable as ubd
devices on x86_64 and other 64 bits systems (segfault of the mm subsystem):
In block/ioctl.c, the following lines show that the BLKGETSIZE ioctl expects
a pointer to a long:
case BLKGETSIZE:
if ((bdev->bd_inode->i_size >> 9) > ~0UL)
return -EFBIG;
return put_ulong(arg, bdev->bd_inode->i_size >> 9);
In arch/um/os-Linux/file.c, os_file_size calls it with an int.
The ioctl_list man page should be fixed as well.
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Stop UML crashing when trying to dump a process core on x86_64. This is the
minimal fix to stop the crash - more things are broken here, and patches are
forthcoming.
The immediate thing to do is define ELF_CORE_COPY_REGS and
ELF_CORE_COPY_FPREGS. Defining ELF_CORE_COPY_FPREGS allows dump_fpu to go
away. It is defined in terms of save_fp_registers, so that needs to be added.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2.6.23-rc1 turned up another batch of references from non-__init code to
__init code. In most cases, these were missing __init annotations. In one
case (os_drop_memory), the annotation was present but wrong.
init_maps is __init, but for some reason was being very careful about the
mechanism by which it allocated memory, checking whether it was OK to use
kmalloc (at this point in the boot, it definitely isn't) and using either
alloc_bootmem_low_pages or kmalloc/vmalloc. So, the kmalloc/vmalloc code is
removed.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Restructure do_aio thanks to commments from Ulrich and Al.
Uli started this by seeing that UML's initialization of a struct iocb
initialized fields that it shouldn't.
Al followed up by adding the following cleanups:
eliminating a variable by just using an anonymous structure in
its place.
hoisting a duplicated line out of the switch.
simplifying the error checking at the end.
I added a severity to the printk.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Ulrich Drepper <drepper@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In 2.6.23-rc1, i386 fiddled its string support such that UML started getting
undefined references from modules. The UML asm/string.h was including the
i386 string.h, which defined __HAVE_ARCH_STR*, but the corresponding
implementations weren't being pulled in.
This is fixed by adding arch/i386/lib/string.h to the list of host
architecture files to be pulled in to UML.
A complication is that the libc exports file assumed that the generic strlen
and strstr weren't in use (i.e. __HAVE_ARCH_STR is defined), then they aren't
exported. This is untrue for strlen, which is exported in either case, so
this logic is not needed.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add some exports for hostfs that are required after Alberto Bertogli's fixes
for accessing unlinked host files.
Also did some style cleanups while I was here.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
UML had two wrapper procedures for kmalloc, um_kmalloc and um_kmalloc_atomic
because the flag constants weren't available in userspace code.
kern_constants.h had made kernel constants available for a long time, so there
is no need for these wrappers any more. Rather, userspace code calls kmalloc
directly with the userspace versions of the gfp flags.
kmalloc isn't a real procedure, so I had to essentially copy the inline
wrapper around __kmalloc.
vmalloc also had its own wrapper for no good reason. This is now gone.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
run_helper and run_helper_thread had arguments which were the same in all
callers. run_helper's stack_out was always NULL and run_helper_thread's
stack_order was always 0. These are now gone, and the constants folded
into the code.
Also fixed leaks of the helper stack in the AIO and SIGIO code.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Cleanup of the SIGWINCH support.
Some code and comment reformatting.
The stack used for SIGWINCH threads was leaked. This is now fixed by storing
it with the pid and other information, and freeing it when the thread is
killed.
If something goes wrong with a WIGWINCH thread, and this is discovered in the
interrupt handler, the winch record would leak. It is now freed, except that
the IRQ isn't freed. This is hard to do from interrupt context. This has the
side-effect that the IRQ system maintains a reference to the freed structure,
but that shouldn't cause a problem since the descriptor is disabled.
register_winch_irq is now much better about cleaning up after an
initialization failure.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Distros seem to be removing PAGE_SIZE from asm/page.h. So, the libc side of
UML should stop using it.
I replace it with UM_KERN_PAGE_SIZE, which is defined to be the same as
PAGE_SIZE on the kernel side of the house. I could also use getpagesize(),
but it's more important that UML have the same value of PAGE_SIZE everywhere.
It's conceivable that it could be built with a larger PAGE_SIZE, and use of
getpagesize() would break that badly.
PAGE_MASK got the same treatment, as it is closely tied to PAGE_SIZE.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Make the PTRACE_SYSEMU checking more robust. It will make sure that system
call numbers are reported correctly. If there is a problem, it will disable
PTRACE_SYSEMU use and use PTRACE_SYSCALL instead.
Thanks to Balaji G for helping reproduce this problem.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add a separate IRQ stack. This differs from i386 in having the entire
interrupt run on a separate stack rather than starting on the normal kernel
stack and switching over once some preparation has been done. The underlying
mechanism, is of course, sigaltstack.
Another difference is that interrupts that happen in userspace are handled on
the normal kernel stack. These cause a wait wakeup instead of a signal
delivery so there is no point in trying to switch stacks for these. There's
no other stuff on the stack, so there is no extra stack consumption.
This quirk makes it possible to have the entire interrupt run on a separate
stack - process preemption (and calls to schedule()) happens on a normal
kernel stack. If we enable CONFIG_PREEMPT, this will need to be rethought.
The IRQ stack for CPU 0 is declared in the same way as the initial kernel
stack. IRQ stacks for other CPUs will be allocated dynamically.
An extra field was added to the thread_info structure. When the active
thread_info is copied to the IRQ stack, the real_thread field points back to
the original stack. This makes it easy to tell where to copy the thread_info
struct back to when the interrupt is finished. It also serves as a marker of
a nested interrupt. It is NULL for the first interrupt on the stack, and
non-NULL for any nested interrupts.
Care is taken to behave correctly if a second interrupt comes in when the
thread_info structure is being set up or taken down. I could just disable
interrupts here, but I don't feel like giving up any of the performance gained
by not flipping signals on and off.
If an interrupt comes in during these critical periods, the handler can't run
because it has no idea what shape the stack is in. So, it sets a bit for its
signal in a global mask and returns. The outer handler will deal with this
signal itself.
Atomicity is had with xchg. A nested interrupt that needs to bail out will
xchg its signal mask into pending_mask and repeat in case yet another
interrupt hit at the same time, until the mask stabilizes.
The outermost interrupt will set up the thread_info and xchg a zero into
pending_mask when it is done. At this point, nested interrupts will look at
->real_thread and see that no setup needs to be done. They can just continue
normally.
Similar care needs to be taken when exiting the outer handler. If another
interrupt comes in while it is copying the thread_info, it will drop a bit
into pending_mask. The outer handler will check this and if it is non-zero,
will loop, set up the stack again, and handle the interrupt.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Some tidying of the irq code before introducing irq stacks. Mostly
style fixes, but the timer handler calls the timer code directly
rather than going through the generic sig_handler_common_skas.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Now that we have UM_THREAD_SIZE, we can replace the calculations in
user-space code (an earlier patch took care of the kernel side of the
house).
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Replaced task_protections with stack_protections since they do the same
thing, and task_protections was misnamed anyway.
This needs THREAD_SIZE, so that's imported via common-offsets.h
Also tidied up the code in the vicinity.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
These haven't been fixed for ages. Just make comments out of them.
arch/um/kernel/skas/process.c:181:2: warning: #warning Need to look up
+userspace_pid by cpu
arch/um/kernel/skas/process.c:187:2: warning: #warning Need to look up
+userspace_pid by cpu
arch/um/kernel/skas/process.c:194:2: warning: #warning need to loop over
+userspace_pids in kill_off_processes_skas
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Mark another function as tt-mode only.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
More trimming of the page fault path.
Permissions are passed around in a single int rather than one bit per
int. The permission values are copied from libc so that they can be
passed to mmap and mprotect without any further conversion.
The register sets used by do_syscall_stub and copy_context_skas0 are
initialized once, at boot time, rather than once per call.
wait_stub_done checks whether it is getting the signals it expects by
comparing the wait status to a mask containing bits for the signals of
interest rather than comparing individually to the signal numbers. It
also has one check for a wait failure instead of two. The caller is
expected to do the initial continue of the stub. This gets rid of an
argument and some logic. The fname argument is gone, as that can be
had from a stack trace.
user_signal() is collapsed into userspace() as it is basically one or
two lines of code afterwards.
The physical memory remapping stuff is gone, as it is unused.
flush_tlb_page is inlined.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Give the page fault code a specialized path. There is only one page to look
at, so there's no point in going into the general page table walking code.
There's only going to be one host operation, so there are no opportunities for
merging. So, we go straight to the pte we want, figure out what needs doing,
and do it.
While I was in here, I fixed the wart where the address passed to unmap was a
void *, but an unsigned long to map and protect.
This gives me just under 10% on a kernel build.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Allow deadlocks to be avoided in the AIO code by setting the pipe to the I/O
thread non-blocking.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Rename os_{read_write}_file_k back to os_{read_write}_file, delete
the originals and their bogus infrastructure, and fix all the callers.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Code running on the initial UML stack can't receive or process signals since
current must be valid when IRQs are handled, and there is no current for this
stack.
So, instead of using UML_LONGJMP and UML_SETJMP, which are careful to save and
restore signal state, and, as a side-effect, handle any deferred signals,
start_idle_thread must use the bare equivalents, which don't do anything with
signals.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Dump core after a panic. This will provide better debugging information than
is currently available.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch converts calls in the os layer to os_{read,write}_file to calls
directly to libc read() and write() where it is clear that the I/O buffer is
in the kernel.
We can do that here instead of calling os_{read,write}_file_k since we are in
libc code and can call libc directly.
With the change in the calls, error handling needs to be changed to refer to
errno directly rather than the return value of the call.
CATCH_EINTR wrappers were also added where needed.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch lays some groundwork for the next one, which converts calls to
os_{read,write}_file into {read,write}, by doing some tidying in the affected
areas.
do_not_aio gets restructured to make the final result a bit cleaner.
There are also whitespace and other formatting fixes, fixes in error messages,
and a typo fix.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch starts the removal of a very old, very broken piece of code. This
stems from the problem of passing a userspace buffer into read() or write() on
the host. If that buffer had not yet been faulted in, read and write will
return -EFAULT.
To avoid this problem, the solution was to fault the buffer in before the
system call by touching the pages that hold the buffer by doing a copy-user of
a byte to each page. This is obviously bogus, but it does usually work, in tt
mode, since the kernel and process are in the same address space and userspace
addresses can be accessed directly in the kernel.
In skas mode, where the kernel and process are in separate address spaces, it
is completely bogus because the userspace address, which is invalid in the
kernel, is passed into the system call instead of the corresponding physical
address, which would be valid. Here, it appears that this code, on every host
read() or write(), tries to fault in a random process page. This doesn't seem
to cause any correctness problems, but there is a performance impact. This
patch, and the ones following, result in a 10-15% performance gain on a kernel
build.
This code can't be immediately tossed out because when it is, you can't log
in. Apparently, there is some code in the console driver which depends on
this somehow.
However, we can start removing it by switching the code which does I/O using
kernel addresses to using plain read() and write(). This patch introduces
os_read_file_k and os_write_file_k for use with kernel buffers and converts
all call locations which use obvious kernel buffers to use them. These
include I/O using buffers which are local variables which are on the stack or
kmalloc-ed. Later patches will handle the less obvious cases, followed by a
mass conversion back to the original interface.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Provide a register dump if handle_trap fails. Abstract out ptrace_dump_regs
since it now has two callers.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If there's a segfault inside the kernel, we want a dump of the registers at
the point of the segfault, not the registers at the point of calling panic or
the last userspace registers.
sig_handler_common_skas now uses a static register set in the case of a
SIGSEGV to avoid messing up the process registers if the segfault turns out to
be non-fatal.
The architecture sigcontext-to-pt_regs copying code was repurposed to copy
data out of the SEGV stack frame.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Tidying in preparation for the segfault register dumping patch which follows.
void * pointers are changed to union uml_pt_regs *. This makes the types
match reality, except in arch_fixup, which is changed to operate on a union
uml_pt_regs. This fixes a bug in the call from segv_handler, which passes a
union uml_pt_regs, to segv, which expects to pass a struct sigcontext to
arch_fixup.
Whitespace and other style fixes.
There's also a errno printk fix.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
userspace code used to have to call the kernelspace function page_size() in
order to determine the value of the kernel's PAGE_SIZE. Since this is now
available directly from kern_constants.h as UM_KERN_PAGE_SIZE, page_size() can
be deleted and calls changed to use the constant.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The build started finding calls from non-init to init functions. These are
just cases of init functions not being properly marked, so this patch fixes
that.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
user_util.h isn't needed any more, so delete it and remove all includes of it.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Rescue the useful contents of the soon-to-be-gone user-util.h.
pty.c now gets ptsname from stdlib.h like it should have always done.
CATCH_EINTR is now in os.h, although perhaps all usage should be under
os-Linux at some point.
get_pty is also in os.h.
This patch restores the old definition of ARRAY_SIZE in user.h. This file is
included only in userspace files, so there will be no conflict with the
kernel's new ARRAY_SIZE. The copy of the kernel's ARRAY_SIZE and associated
infrastructure is now gone.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch moves all the the symbols defined in um_arch.c, which are mostly
boundaries between different parts of the UML kernel address space, to a new
header, as-layout.h. There are also a few things here which aren't really
related to address space layout, but which don't really have a better place to
go.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch narrows the sigio interface. The boot-time SIGIO testing used to
be in start_up.c, which meant that pty_output_sigio and pty_close_sigio needed
to be global. By moving that code here, those can become static and the
declarations moved from user_util.h.
os_check_bugs is also here because it only does the SIGIO checking. If it
does more, it'll probably move back to start_up.c.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This fixes a number of problems associated with network interface hotplug.
The userspace initialization function can fail in some cases, but the
failure was never passed back to eth_configure, which proceeded with the
configuration. This results in a zombie device that is present, but can't
work. This is fixed by allowing the initialization routines to return an
error, which is checked, and the configuration aborted on failure.
eth_configure failed to check for many failures. Even when it did check,
it didn't undo whatever initializations has already happened, so a present,
but partially initialized and non-working device could result. It now
checks everything that can fail, and bails out, undoing whatever had been
done.
The return value of eth_configure was always ignored, so it is now just
void.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Jeff Garzik <jeff@garzik.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix a bunch of formatting violations in the drivers:
return(n) -> return n
whitespace fixes
emacs formatting comment removal
breaking if(foo) return(n) into two lines
There are also a couple of errno use bugs:
using errno in a printk when the failure put errno into a local variable
saving errno after a printk, which can change it
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Print out core dump limits at boot time. This is to allow core dumps
to be collected if something goes very wrong and to tell if a core
dump isn't going to happen because of a resource limit.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Move the host_info string from util.c to um_arch.c, where it is
actually initialized and used. Also document its lack of locking.
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Get rid of a bunch of unused stuff -
cpu_feature had no users
linux_prog is little-used, so its declaration is moved to the
user for easy deletion when the whole file goes away
a long-unused debugging aid in helper.c is gone
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
For the places where we need a pointer to the mac header, it is still legal to
touch skb->mac.raw directly if just adding to, subtracting from or setting it
to another layer header.
This one also converts some more cases to skb_reset_mac_header() that my
regex missed as it had no spaces before nor after '=', ugh.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch uses MAX_REG_NR consistently to refer to the register file size.
FRAME_SIZE isn't sufficient because on x86_64, it is smaller than the
ptrace register file size. MAX_REG_NR was introduced as a consistent way
to get the number of registers, but wasn't used everywhere it should be.
When this causes a problem, it makes PTRACE_SETREGS fail on x86_64 because
of a corrupted segment register value in the known-good register file. The
patch also adds a register dump at that point in case there are any future
problems here.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
os_usr1_signal() is totally unused, os_usr1_process() is used only by TT mode.
Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Acked-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Comment the fact that sig_info is initialized early in boot, and thus doesn't
need any locking.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add a debugging message in the case that mapping a stub fails.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This fixes a problem seen by a number of people running UML on newer host
kernels. init would hang with an infinite segfault loop.
It turns out that the host kernel was providing a AT_SYSINFO_EHDR of
0xffffe000, which faked UML into believing that the host VDSO page could be
reused. However, AT_SYSINFO pointed into the middle of the address space, and
was unmapped as a result. Because UML was providing AT_SYSINFO_EHDR and
AT_SYSINFO to its own processes, these would branch to nowhere when trying to
use the VDSO.
The fix is to also check the location of AT_SYSINFO when deciding whether to
use the host's VDSO.
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In the 2.6.20 hang patch, I accidentally threw out an error message.
This puts it back.
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
A previous cleanup misused need_poll, which had a fairly broken interface.
It implemented a growable array, changing the used elements count itself,
but leaving it up to the caller to fill in the actual elements, including
the entire array if the array had to be reallocated. This worked because
the previous users were switching between two such structures, and the
elements were copied from the inactive array to the active array after
making sure the active array had enough room.
maybe_sigio_broken was made to use need_poll, but it was operating on a
single array, so when the buffer was reallocated, the previous contents
were lost.
This patch makes need_poll implement more sane semantics. It merely
assures that the array is of the proper size and that the contents are
preserved. It is up to the caller to adjust the used elements count and to
ensure that the proper elements are resent.
This manifested itself as a hang in 2.6.20 as the uninitialized buffer
convinced UML that one of its own file descriptors didn't support SIGIO and
needed to be watched by poll in a separate thread. The result was an
interrupt flood as control traffic over this descriptor sparked interrupts,
which resulted in more control traffic, ad nauseum.
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Jeff Dike
Nicolas George
Miklos Szeredi
Arnaldo Carvalho de Melo
Paolo 'Blaisorblade' Giarrusso