brain-hackers_pepepper-mirror
/
linux-brain
mirror of https://github.com/brain-hackers/linux-brain.git
1
0
Fork 0
Code Issues Projects Releases Wiki Activity

perf/x86/regs: Check reserved bits 

The perf fuzzer triggers a warning which map to:

        if (WARN_ON_ONCE(idx >= ARRAY_SIZE(pt_regs_offset)))
                return 0;

The bits between XMM registers and generic registers are reserved.
But perf_reg_validate() doesn't check these bits.

Add PERF_REG_X86_RESERVED for reserved bits on X86.
Check the reserved bits in perf_reg_validate().

Reported-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: 878068ea27 ("perf/x86: Support outputting XMM registers")
Link: https://lkml.kernel.org/r/1559081314-9714-2-git-send-email-kan.liang@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Kan Liang 2019-05-28 15:08:31 -07:00 committed by Ingo Molnar
parent e321d02db8
commit 90d424915a
1 changed files with 5 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

7
arch/x86/kernel/perf_regs.c
View File

@ -74,6 +74,9 @@ u64 perf_reg_value(struct pt_regs *regs, int idx)
return regs_get_register(regs, pt_regs_offset[idx]);
}
#define PERF_REG_X86_RESERVED (((1ULL << PERF_REG_X86_XMM0) - 1) & \
~((1ULL << PERF_REG_X86_MAX) - 1))
#ifdef CONFIG_X86_32
#define REG_NOSUPPORT ((1ULL << PERF_REG_X86_R8) | \
(1ULL << PERF_REG_X86_R9) | \
@ -86,7 +89,7 @@ u64 perf_reg_value(struct pt_regs *regs, int idx)
int perf_reg_validate(u64 mask)
{
if (!mask || (mask & REG_NOSUPPORT))
if (!mask || (mask & (REG_NOSUPPORT | PERF_REG_X86_RESERVED)))
return -EINVAL;
return 0;
@ -112,7 +115,7 @@ void perf_get_regs_user(struct perf_regs *regs_user,
int perf_reg_validate(u64 mask)
{
if (!mask || (mask & REG_NOSUPPORT))
if (!mask || (mask & (REG_NOSUPPORT | PERF_REG_X86_RESERVED)))
return -EINVAL;
return 0;