linux-sg2042/arch
Thomas Gleixner d2753e6b48 perf/x86/amd/ibs: Don't access non-started event
Paul Menzel reported the following bug:

> Enabling the undefined behavior sanitizer and building GNU/Linux 4.18-rc5+
> (with some unrelated commits) with GCC 8.1.0 from Debian Sid/unstable, the
> warning below is shown.
>
> > [    2.111913]
> > ================================================================================
> > [    2.111917] UBSAN: Undefined behaviour in arch/x86/events/amd/ibs.c:582:24
> > [    2.111919] member access within null pointer of type 'struct perf_event'
> > [    2.111926] CPU: 0 PID: 144 Comm: udevadm Not tainted 4.18.0-rc5-00316-g4864b68cedf2 #104
> > [    2.111928] Hardware name: ASROCK E350M1/E350M1, BIOS TIMELESS 01/01/1970
> > [    2.111930] Call Trace:
> > [    2.111943]  dump_stack+0x55/0x89
> > [    2.111949]  ubsan_epilogue+0xb/0x33
> > [    2.111953]  handle_null_ptr_deref+0x7f/0x90
> > [    2.111958]  __ubsan_handle_type_mismatch_v1+0x55/0x60
> > [    2.111964]  perf_ibs_handle_irq+0x596/0x620

The code dereferences event before checking the STARTED bit. Patch
below should cure the issue.

The warning should not trigger, if I analyzed the thing correctly.
(And Paul's testing confirms this.)

Reported-by: Paul Menzel <pmenzel@molgen.mpg.de>
Tested-by: Paul Menzel <pmenzel@molgen.mpg.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul Menzel <pmenzel+linux-x86@molgen.mpg.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Link: http://lkml.kernel.org/r/alpine.DEB.2.21.1807200958390.1580@nanos.tec.linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-24 09:51:10 +02:00
..
alpha alpha: fix osf_wait4() breakage 2018-07-22 11:51:30 -07:00
arc ARC fixes for 4.18-rc6 2018-07-20 11:33:22 -07:00
arm ARM: SoC fixes for 4.18-rc 2018-07-21 17:27:42 -07:00
arm64 arm64: neon: Fix function may_use_simd() return error status 2018-07-11 17:02:02 +01:00
c6x Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-06-04 20:27:54 -07:00
h8300 Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-06-04 20:27:54 -07:00
hexagon hexagon: drop the unused variable zero_page_mask 2018-06-15 07:55:25 +09:00
ia64 mm: make vm_area_alloc() initialize core fields 2018-07-21 15:24:03 -07:00
m68k m68k: fix "bad page state" oops on ColdFire boot 2018-07-02 10:05:13 +10:00
microblaze Microblaze patches for 4.18-rc3 2018-06-27 09:49:30 -07:00
mips MIPS: Fix ioremap() RAM check 2018-07-05 14:43:21 -07:00
nds32 nds32: fix build error "relocation truncated to fit: R_NDS32_25_PCREL_RELA" when 2018-07-05 16:13:47 +08:00
nios2 Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-06-04 20:27:54 -07:00
openrisc openrisc: entry: Fix delay slot exception detection 2018-07-01 16:48:24 +09:00
parisc parisc: Build kernel without -ffunction-sections 2018-06-29 17:27:20 +02:00
powerpc powerpc/powernv: Fix save/restore of SPRG3 on entry/exit from stop (idle) 2018-07-18 20:40:17 +10:00
riscv RISC-V: Fix the rv32i kernel build 2018-07-04 14:12:53 -07:00
s390 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux 2018-07-06 09:14:34 -07:00
sh arch/*: Kconfig: fix documentation for NMI watchdog 2018-06-15 12:48:59 -03:00
sparc arch/*: Kconfig: fix documentation for NMI watchdog 2018-06-15 12:48:59 -03:00
um Solve a series of broken links for files under Documentation: 2018-06-17 05:25:18 +09:00
unicore32 docs: Fix some broken references 2018-06-15 18:10:01 -03:00
x86 perf/x86/amd/ibs: Don't access non-started event 2018-07-24 09:51:10 +02:00
xtensa docs: Fix some broken references 2018-06-15 18:10:01 -03:00
.gitignore
Kconfig docs: Fix some broken references 2018-06-15 18:10:01 -03:00