linux/arch
Andy Lutomirski a27507ca2d x86/nmi/64: Reorder nested NMI checks
Check the repeat_nmi .. end_repeat_nmi special case first.  The
next patch will rework the RSP check and, as a side effect, the
RSP check will no longer detect repeat_nmi .. end_repeat_nmi, so
we'll need this ordering of the checks.

Note: this is more subtle than it appears.  The check for
repeat_nmi .. end_repeat_nmi jumps straight out of the NMI code
instead of adjusting the "iret" frame to force a repeat.  This
is necessary, because the code between repeat_nmi and
end_repeat_nmi sets "NMI executing" and then writes to the
"iret" frame itself.  If a nested NMI comes in and modifies the
"iret" frame while repeat_nmi is also modifying it, we'll end up
with garbage.  The old code got this right, as does the new
code, but the new code is a bit more explicit.

If we were to move the check right after the "NMI executing"
check, then we'd get it wrong and have random crashes.

( Because the "NMI executing" check would jump to the code that would
  modify the "iret" frame without checking if the interrupted NMI was
  currently modifying it. )

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Borislav Petkov <bp@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-07-17 12:50:12 +02:00
..
alpha TTY/Serial driver patches for 4.2-rc1 2015-06-26 15:53:22 -07:00
arc ARCv2: support HS38 releases 2015-07-13 13:33:23 +05:30
arm Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2015-07-13 11:18:25 -07:00
arm64 ARM: SoC: fixes for v4.2-rc2 2015-07-11 10:20:36 -07:00
avr32 Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2015-07-01 15:19:35 -07:00
blackfin Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2015-07-04 19:36:06 -07:00
c6x Merge branch 'for-4.2/sg' of git://git.kernel.dk/linux-block 2015-06-25 15:22:36 -07:00
cris cris: Replace do_posix_clock_monotonic_gettime() 2015-07-09 10:51:46 +02:00
frv Fix up implicit <module.h> users that will break later. 2015-07-02 10:25:22 -07:00
h8300 h8300: Always build dtb 2015-06-23 13:36:00 +09:00
hexagon Merge branch 'for-4.2/sg' of git://git.kernel.dk/linux-block 2015-06-25 15:22:36 -07:00
ia64 remove some boot noise from a now-invalid check that pages are reserved 2015-07-02 14:46:15 -07:00
m32r Merge branch 'for-4.2/sg' of git://git.kernel.dk/linux-block 2015-06-25 15:22:36 -07:00
m68k m68k: enable PCI support for m5475evb defconfig 2015-07-13 09:34:40 +10:00
metag Merge branch 'akpm' (patches from Andrew) 2015-06-26 09:52:05 -07:00
microblaze Merge branch 'for-4.2/sg' of git://git.kernel.dk/linux-block 2015-06-25 15:22:36 -07:00
mips MIPS: O32: Use compat_sys_getsockopt. 2015-07-10 11:02:22 +02:00
mn10300 Replace module_init with equivalent device_initcall in non modules. 2015-07-02 10:30:48 -07:00
nios2 nios2 update for v4.2 2015-07-03 12:22:49 -07:00
openrisc Merge branch 'for-4.2/sg' of git://git.kernel.dk/linux-block 2015-06-25 15:22:36 -07:00
parisc parisc: Fix some PTE/TLB race conditions and optimize __flush_tlb_range based on timing results 2015-07-10 21:47:47 +02:00
powerpc powerpc/perf/24x7: Fix lockdep warning 2015-07-08 15:18:04 +10:00
s390 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux 2015-07-15 13:12:44 -07:00
score Merge branch 'for-4.2/sg' of git://git.kernel.dk/linux-block 2015-06-25 15:22:36 -07:00
sh Replace module_init with equivalent device_initcall in non modules. 2015-07-02 10:30:48 -07:00
sparc Merge branch 'akpm' (patches from Andrew) 2015-06-26 09:52:05 -07:00
tile modpost: work correctly with tile coldtext sections 2015-07-08 18:53:49 -04:00
um Minor merge needed, due to function move. 2015-07-01 10:49:25 -07:00
unicore32 arch/unicore32/kernel/fpu-ucf64.c: remove unnecessary KERN_ERR 2015-06-30 19:44:59 -07:00
x86 x86/nmi/64: Reorder nested NMI checks 2015-07-17 12:50:12 +02:00
xtensa Replace module_init with equivalent device_initcall in non modules. 2015-07-02 10:30:48 -07:00
.gitignore
Kconfig clone: support passing tls argument via C rather than pt_regs magic 2015-06-25 17:00:38 -07:00