[PATCH 0/4] perf: Support multiple stacks (v3)

From: Arun Sharma
Date: Fri Apr 20 2012 - 18:52:52 EST

If userspace has two or more stacks and we happen to take a sample when
the stack pointer is pointing to a higher stack, we get truncated
callchains. This patch series tries to address that.


v3: add explicit checks to copy_from_user_nmi
v3: add explicit checks in perf_callchain_user*

v2: do this for compat32 as well
v2: improve safety checks and reduce max callchain size

Arun Sharma (4):
perf, x86: Allow multiple stacks
perf: Limit callchains to 127
perf, x86: Check if user fp is valid
x86: Check user address explicitly in copy_from_user_nmi()

arch/x86/include/asm/uaccess.h | 13 +++++++------
arch/x86/kernel/cpu/perf_event.c | 11 +++++++++--
arch/x86/lib/usercopy.c | 3 +++
include/linux/perf_event.h | 2 +-
4 files changed, 20 insertions(+), 9 deletions(-)


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