[PATCH] perf/x86: set pmu->module in Intel PMU modules

* [PATCH] perf/x86: set pmu->module in Intel PMU modules
@ 2016-12-23  1:17 David Carrillo-Cisneros
  2017-01-05 15:07 ` [tip:perf/urgent] perf/x86: Set " tip-bot for David Carrillo-Cisneros
  0 siblings, 1 reply; 5+ messages in thread
From: David Carrillo-Cisneros @ 2016-12-23  1:17 UTC (permalink / raw)
  To: linux-kernel
  Cc: x86, Ingo Molnar, Thomas Gleixner, Andi Kleen, Kan Liang,
	Peter Zijlstra, Borislav Petkov, Srinivas Pandruvada,
	Dave Hansen, Paul Turner, Stephane Eranian,
	David Carrillo-Cisneros

The conversion of Intel PMU drivers into modules did not include reference
counting. The machine will crash when attempting to  access deleted code
if an event from a module PMU is started and the module removed before the
event is destroyed.

i.e. this crashes the machine:

	$ insmod intel-rapl-perf.ko
	$ perf stat -e power/energy-cores/ -C 0 &
	$ rmmod intel-rapl-perf.ko

Set THIS_MODULE to pmu->module in Intel module PMUs so that generic code
can handle reference counting and deny rmmod while an event still exists.

Signed-off-by: David Carrillo-Cisneros <davidcc@google.com>
---
 arch/x86/events/intel/cstate.c | 2 ++
 arch/x86/events/intel/rapl.c   | 1 +
 arch/x86/events/intel/uncore.c | 1 +
 3 files changed, 4 insertions(+)

diff --git a/arch/x86/events/intel/cstate.c b/arch/x86/events/intel/cstate.c
index da51e5a..5c08fc7 100644
--- a/arch/x86/events/intel/cstate.c
+++ b/arch/x86/events/intel/cstate.c
@@ -434,6 +434,7 @@ static struct pmu cstate_core_pmu = {
 	.stop		= cstate_pmu_event_stop,
 	.read		= cstate_pmu_event_update,
 	.capabilities	= PERF_PMU_CAP_NO_INTERRUPT,
+	.module		= THIS_MODULE,
 };
 
 static struct pmu cstate_pkg_pmu = {
@@ -447,6 +448,7 @@ static struct pmu cstate_pkg_pmu = {
 	.stop		= cstate_pmu_event_stop,
 	.read		= cstate_pmu_event_update,
 	.capabilities	= PERF_PMU_CAP_NO_INTERRUPT,
+	.module		= THIS_MODULE,
 };
 
 static const struct cstate_model nhm_cstates __initconst = {
diff --git a/arch/x86/events/intel/rapl.c b/arch/x86/events/intel/rapl.c
index 0a535ce..6f2cbd5 100644
--- a/arch/x86/events/intel/rapl.c
+++ b/arch/x86/events/intel/rapl.c
@@ -697,6 +697,7 @@ static int __init init_rapl_pmus(void)
 	rapl_pmus->pmu.start		= rapl_pmu_event_start;
 	rapl_pmus->pmu.stop		= rapl_pmu_event_stop;
 	rapl_pmus->pmu.read		= rapl_pmu_event_read;
+	rapl_pmus->pmu.module		= THIS_MODULE;
 	return 0;
 }
 
diff --git a/arch/x86/events/intel/uncore.c b/arch/x86/events/intel/uncore.c
index dbaaf7dc..2fe525b 100644
--- a/arch/x86/events/intel/uncore.c
+++ b/arch/x86/events/intel/uncore.c
@@ -733,6 +733,7 @@ static int uncore_pmu_register(struct intel_uncore_pmu *pmu)
 			.start		= uncore_pmu_event_start,
 			.stop		= uncore_pmu_event_stop,
 			.read		= uncore_pmu_event_read,
+			.module		= THIS_MODULE,
 		};
 	} else {
 		pmu->pmu = *pmu->type->pmu;
-- 
2.8.0.rc3.226.g39d4020

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