[014/118] perf/x86: Fix offcore_rsp valid mask for SNB/IVB

Message ID 1367933964-1564-15-git-send-email-luis.henriques@canonical.com
State New
Headers show

Commit Message

Luis Henriques May 7, 2013, 1:37 p.m. -stable review patch.  If anyone has any objections, please let me know.


From: Stephane Eranian <eranian@google.com>

commit f1923820c447e986a9da0fc6bf60c1dccdf0408e upstream.

The valid mask for both offcore_response_0 and
offcore_response_1 was wrong for SNB/SNB-EP,
IVB/IVB-EP. It was possible to write to
reserved bit and cause a GP fault crashing
the kernel.

This patch fixes the problem by correctly marking the
reserved bits in the valid mask for all the processors
mentioned above.

A distinction between desktop and server parts is introduced
because bits 24-30 are only available on the server parts.

This version of the  patch is just a rebase to perf/urgent tree
and should apply to older kernels as well.

Signed-off-by: Stephane Eranian <eranian@google.com>
Cc: peterz@infradead.org
Cc: jolsa@redhat.com
Cc: gregkh@linuxfoundation.org
Cc: security@kernel.org
Cc: ak@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
[ luis: backport to 3.5: dropped IvyBridge changes ]
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
 arch/x86/kernel/cpu/perf_event_intel.c | 15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)


diff --git a/arch/x86/kernel/cpu/perf_event_intel.c b/arch/x86/kernel/cpu/perf_event_intel.c
index 187c294..54082f7 100644
--- a/arch/x86/kernel/cpu/perf_event_intel.c
+++ b/arch/x86/kernel/cpu/perf_event_intel.c
@@ -126,8 +126,14 @@  static struct event_constraint intel_gen_event_constraints[] __read_mostly =
 static struct extra_reg intel_snb_extra_regs[] __read_mostly = {
-	INTEL_EVENT_EXTRA_REG(0xb7, MSR_OFFCORE_RSP_0, 0x3fffffffffull, RSP_0),
-	INTEL_EVENT_EXTRA_REG(0xbb, MSR_OFFCORE_RSP_1, 0x3fffffffffull, RSP_1),
+	INTEL_EVENT_EXTRA_REG(0xb7, MSR_OFFCORE_RSP_0, 0x3f807f8fffull, RSP_0),
+	INTEL_EVENT_EXTRA_REG(0xbb, MSR_OFFCORE_RSP_1, 0x3f807f8fffull, RSP_1),
+static struct extra_reg intel_snbep_extra_regs[] __read_mostly = {
+	INTEL_EVENT_EXTRA_REG(0xb7, MSR_OFFCORE_RSP_0, 0x3fffff8fffull, RSP_0),
+	INTEL_EVENT_EXTRA_REG(0xbb, MSR_OFFCORE_RSP_1, 0x3fffff8fffull, RSP_1),
@@ -1920,7 +1926,10 @@  __init int intel_pmu_init(void)
 		x86_pmu.event_constraints = intel_snb_event_constraints;
 		x86_pmu.pebs_constraints = intel_snb_pebs_event_constraints;
 		x86_pmu.pebs_aliases = intel_pebs_aliases_snb;
-		x86_pmu.extra_regs = intel_snb_extra_regs;
+		if (boot_cpu_data.x86_model == 45)
+			x86_pmu.extra_regs = intel_snbep_extra_regs;
+		else
+			x86_pmu.extra_regs = intel_snb_extra_regs;
 		/* all extra regs are per-cpu when HT is on */
 		x86_pmu.er_flags |= ERF_HAS_RSP_1;
 		x86_pmu.er_flags |= ERF_NO_HT_SHARING;