4.14-stable review patch. If anyone has any objections, please let me know.
------------------
From: Andi Kleen ak@linux.intel.com
commit 2fe1bc1f501d55e5925b4035bcd85781adc76c63 upstream.
[ Note, this is a Git cherry-pick of the following commit:
a47ba4d77e12 ("perf/x86: Enable free running PEBS for REGS_USER/INTR")
... for easier x86 PTI code testing and back-porting. ]
Currently free running PEBS is disabled when user or interrupt registers are requested. Most of the registers are actually available in the PEBS record and can be supported.
So we just need to check for the supported registers and then allow it: it is all except for the segment register.
For user registers this only works when the counter is limited to ring 3 only, so this also needs to be checked.
Signed-off-by: Andi Kleen ak@linux.intel.com Signed-off-by: Peter Zijlstra (Intel) peterz@infradead.org Cc: Linus Torvalds torvalds@linux-foundation.org Cc: Peter Zijlstra peterz@infradead.org Cc: Thomas Gleixner tglx@linutronix.de Link: http://lkml.kernel.org/r/20170831214630.21892-1-andi@firstfloor.org Signed-off-by: Ingo Molnar mingo@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- arch/x86/events/intel/core.c | 4 ++++ arch/x86/events/perf_event.h | 24 +++++++++++++++++++++++- 2 files changed, 27 insertions(+), 1 deletion(-)
--- a/arch/x86/events/intel/core.c +++ b/arch/x86/events/intel/core.c @@ -2958,6 +2958,10 @@ static unsigned long intel_pmu_free_runn
if (event->attr.use_clockid) flags &= ~PERF_SAMPLE_TIME; + if (!event->attr.exclude_kernel) + flags &= ~PERF_SAMPLE_REGS_USER; + if (event->attr.sample_regs_user & ~PEBS_REGS) + flags &= ~(PERF_SAMPLE_REGS_USER | PERF_SAMPLE_REGS_INTR); return flags; }
--- a/arch/x86/events/perf_event.h +++ b/arch/x86/events/perf_event.h @@ -85,13 +85,15 @@ struct amd_nb { * Flags PEBS can handle without an PMI. * * TID can only be handled by flushing at context switch. + * REGS_USER can be handled for events limited to ring 3. * */ #define PEBS_FREERUNNING_FLAGS \ (PERF_SAMPLE_IP | PERF_SAMPLE_TID | PERF_SAMPLE_ADDR | \ PERF_SAMPLE_ID | PERF_SAMPLE_CPU | PERF_SAMPLE_STREAM_ID | \ PERF_SAMPLE_DATA_SRC | PERF_SAMPLE_IDENTIFIER | \ - PERF_SAMPLE_TRANSACTION | PERF_SAMPLE_PHYS_ADDR) + PERF_SAMPLE_TRANSACTION | PERF_SAMPLE_PHYS_ADDR | \ + PERF_SAMPLE_REGS_INTR | PERF_SAMPLE_REGS_USER)
/* * A debug store configuration. @@ -110,6 +112,26 @@ struct debug_store { u64 pebs_event_reset[MAX_PEBS_EVENTS]; };
+#define PEBS_REGS \ + (PERF_REG_X86_AX | \ + PERF_REG_X86_BX | \ + PERF_REG_X86_CX | \ + PERF_REG_X86_DX | \ + PERF_REG_X86_DI | \ + PERF_REG_X86_SI | \ + PERF_REG_X86_SP | \ + PERF_REG_X86_BP | \ + PERF_REG_X86_IP | \ + PERF_REG_X86_FLAGS | \ + PERF_REG_X86_R8 | \ + PERF_REG_X86_R9 | \ + PERF_REG_X86_R10 | \ + PERF_REG_X86_R11 | \ + PERF_REG_X86_R12 | \ + PERF_REG_X86_R13 | \ + PERF_REG_X86_R14 | \ + PERF_REG_X86_R15) + /* * Per register state. */