From: Stephane Eranian Date: Thu, 6 Jun 2013 09:02:04 +0000 (+0200) Subject: perf: Fix hypervisor branch sampling permission check X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=e712209a9e0b70e78b13847738eb66fe37412515;p=linux-beck.git perf: Fix hypervisor branch sampling permission check Commit 2b923c8 perf/x86: Check branch sampling priv level in generic code was missing the check for the hypervisor (HV) priv level, so add it back. With this patch, we get the following correct behavior: # echo 2 >/proc/sys/kernel/perf_event_paranoid $ perf record -j any,k noploop 1 Error: You may not have permission to collect stats. Consider tweaking /proc/sys/kernel/perf_event_paranoid: -1 - Not paranoid at all 0 - Disallow raw tracepoint access for unpriv 1 - Disallow cpu events for unpriv 2 - Disallow kernel profiling for unpriv $ perf record -j any,hv noploop 1 Error: You may not have permission to collect stats. Consider tweaking /proc/sys/kernel/perf_event_paranoid: -1 - Not paranoid at all 0 - Disallow raw tracepoint access for unpriv 1 - Disallow cpu events for unpriv 2 - Disallow kernel profiling for unpriv Signed-off-by: Stephane Eranian Acked-by: Petr Matousek Signed-off-by: Peter Zijlstra Link: http://lkml.kernel.org/r/20130606090204.GA3725@quad Signed-off-by: Ingo Molnar --- diff --git a/kernel/events/core.c b/kernel/events/core.c index d0e0d0d2025f..aca95bce34c8 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -6573,8 +6573,8 @@ static int perf_copy_attr(struct perf_event_attr __user *uattr, */ attr->branch_sample_type = mask; } - /* kernel level capture: check permissions */ - if ((mask & PERF_SAMPLE_BRANCH_KERNEL) + /* privileged levels capture (kernel, hv): check permissions */ + if ((mask & PERF_SAMPLE_BRANCH_PERM_PLM) && perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN)) return -EACCES; }