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