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mirror of https://github.com/edk2-porting/linux-next.git synced 2024-12-24 13:13:57 +08:00
linux-next/arch
Josh Poimboeuf ff3f7e2475 x86/entry: Fix the end of the stack for newly forked tasks
When unwinding a task, the end of the stack is always at the same offset
right below the saved pt_regs, regardless of which syscall was used to
enter the kernel.  That convention allows the unwinder to verify that a
stack is sane.

However, newly forked tasks don't always follow that convention, as
reported by the following unwinder warning seen by Dave Jones:

  WARNING: kernel stack frame pointer at ffffc90001443f30 in kworker/u8:8:30468 has bad value           (null)

The warning was due to the following call chain:

  (ftrace handler)
  call_usermodehelper_exec_async+0x5/0x140
  ret_from_fork+0x22/0x30

The problem is that ret_from_fork() doesn't create a stack frame before
calling other functions.  Fix that by carefully using the frame pointer
macros.

In addition to conforming to the end of stack convention, this also
makes related stack traces more sensible by making it clear to the user
that ret_from_fork() was involved.

Reported-by: Dave Jones <davej@codemonkey.org.uk>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Miroslav Benes <mbenes@suse.cz>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/8854cdaab980e9700a81e9ebf0d4238e4bbb68ef.1483978430.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-01-12 09:28:29 +01:00
..
alpha clocksource: Use a plain u64 instead of cycle_t 2016-12-25 11:04:12 +01:00
arc 2nd round of ARC udpates for 4.10rc1 2016-12-23 10:22:47 -08:00
arm Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-12-25 14:30:04 -08:00
arm64 arm64: don't pull uaccess.h into *.S 2016-12-26 13:05:17 -05:00
avr32 clocksource: Use a plain u64 instead of cycle_t 2016-12-25 11:04:12 +01:00
blackfin Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-12-25 14:30:04 -08:00
c6x clocksource: Use a plain u64 instead of cycle_t 2016-12-25 11:04:12 +01:00
cris Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
frv Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
h8300 Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
hexagon clocksource: Use a plain u64 instead of cycle_t 2016-12-25 11:04:12 +01:00
ia64 clocksource: Use a plain u64 instead of cycle_t 2016-12-25 11:04:12 +01:00
m32r Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
m68k clocksource: Use a plain u64 instead of cycle_t 2016-12-25 11:04:12 +01:00
metag Merge branch 'smp-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-12-25 14:05:56 -08:00
microblaze clocksource: Use a plain u64 instead of cycle_t 2016-12-25 11:04:12 +01:00
mips Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-12-25 14:30:04 -08:00
mn10300 clocksource: Use a plain u64 instead of cycle_t 2016-12-25 11:04:12 +01:00
nios2 clocksource: Use a plain u64 instead of cycle_t 2016-12-25 11:04:12 +01:00
openrisc openrisc: Add _text symbol to fix ksym build error 2017-01-02 10:35:11 +09:00
parisc parisc: Add line-break when printing segfault info 2017-01-02 18:07:25 +01:00
powerpc powerpc: Fix build warning on 32-bit PPC 2016-12-25 16:12:20 -08:00
s390 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux 2017-01-02 09:08:45 -08:00
score Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
sh Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
sparc clocksource: Use a plain u64 instead of cycle_t 2016-12-25 11:04:12 +01:00
tile Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
um clocksource: Use a plain u64 instead of cycle_t 2016-12-25 11:04:12 +01:00
unicore32 clocksource: Use a plain u64 instead of cycle_t 2016-12-25 11:04:12 +01:00
x86 x86/entry: Fix the end of the stack for newly forked tasks 2017-01-12 09:28:29 +01:00
xtensa Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-12-25 14:30:04 -08:00
.gitignore
Kconfig powerpc: ima: get the kexec buffer passed by the previous kernel 2016-12-20 09:48:40 -08:00