[PATCH 0/2] perf/x86/intel: Work around BTS leaking kernel addresses

From: Alexander Shishkin
Date: Thu Aug 27 2015 - 11:14:36 EST

Hi Peter,

Due to imprecise IP sampling, BTS may (and often does) leak kernel
addresses when kernel tracing is not even enabled, which results in
mostly syscall entry points and page_fault handler addresses being
exposed. This might be a security concern for the address
randomization, and it also makes life harder for gdb that makes use of
bts samples.

This patchset works around the old (DS) driver and disables the new
(intel_bts) for the unprivileged users on systems where perf paranoia
level prohibits kernel tracing.

Not sure if these should be treated as bugfixes.

Alexander Shishkin (2):
perf/x86/intel/ds: Work around BTS leaking kernel addresses
perf/x86/intel/bts: Disallow use by unprivileged users on paranoid

arch/x86/kernel/cpu/perf_event_intel_bts.c | 10 ++++++++
arch/x86/kernel/cpu/perf_event_intel_ds.c | 40 +++++++++++++++++++++++++-----
2 files changed, 44 insertions(+), 6 deletions(-)


To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/