From ec84d529b689f4ae31813cf74673f3271c36c83a Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Mon, 14 Nov 2011 16:12:52 +0000 Subject: [PATCH 1/4] ARM: PMU: re-export release_pmu symbol to modules Commit b0e89590 ("ARM: PMU: move CPU PMU platform device handling and init into perf") inadvertently removed the EXPORT_SYMBOL_GPL on release_pmu, so out-of-tree modules can no longer play nice with perf, even if they tried in the first place. This patch re-exports the symbol. Reported-by: Jon Medhurst (Tixy) Signed-off-by: Will Deacon --- arch/arm/kernel/pmu.c | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/arm/kernel/pmu.c b/arch/arm/kernel/pmu.c index 2c3407ee8576..2334bf8a650a 100644 --- a/arch/arm/kernel/pmu.c +++ b/arch/arm/kernel/pmu.c @@ -33,3 +33,4 @@ release_pmu(enum arm_pmu_type type) { clear_bit_unlock(type, pmu_lock); } +EXPORT_SYMBOL_GPL(release_pmu); From 14e25c5eeb90d4f61cc94933307d04a19738ad2f Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Wed, 16 Nov 2011 10:05:18 +0000 Subject: [PATCH 2/4] ARM: PMU: remove pmu_init declaration pmu_init no longer exists, so don't declare it in asm/pmu.h. Reported-by: Pawel Moll Signed-off-by: Will Deacon --- arch/arm/include/asm/pmu.h | 10 ---------- 1 file changed, 10 deletions(-) diff --git a/arch/arm/include/asm/pmu.h b/arch/arm/include/asm/pmu.h index 71d99b83cdb9..0bda22c094a6 100644 --- a/arch/arm/include/asm/pmu.h +++ b/arch/arm/include/asm/pmu.h @@ -55,16 +55,6 @@ reserve_pmu(enum arm_pmu_type type); extern void release_pmu(enum arm_pmu_type type); -/** - * init_pmu() - Initialise the PMU. - * - * Initialise the system ready for PMU enabling. This should typically set the - * IRQ affinity and nothing else. The users (oprofile/perf events etc) will do - * the actual hardware initialisation. - */ -extern int -init_pmu(enum arm_pmu_type type); - #else /* CONFIG_CPU_HAS_PMU */ #include From bce34d14428d35d9a06ddc10cd46ecef311764c9 Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Thu, 17 Nov 2011 15:05:14 +0000 Subject: [PATCH 3/4] ARM: perf: initialise used_mask for fake PMU during validation When validating an event group, we call pmu->get_event_idx for each group member in order to check that the group can be scheduled as a unit on an empty PMU. As a result of 3fc2c830 ("ARM: perf: remove event limit from pmu_hw_events"), the used_mask member of struct cpu_hw_events must be setup explicitly, something which we don't do for the fake cpu_hw_events used for validation. This patch sets up an empty used_mask for the fake validation cpu_hw_events, preventing NULL deferences when trying to get the event index. Reported-by: Pawel Moll Signed-off-by: Will Deacon --- arch/arm/kernel/perf_event.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/arch/arm/kernel/perf_event.c b/arch/arm/kernel/perf_event.c index 24e2347be6b1..e508066d3d64 100644 --- a/arch/arm/kernel/perf_event.c +++ b/arch/arm/kernel/perf_event.c @@ -343,8 +343,14 @@ validate_group(struct perf_event *event) { struct perf_event *sibling, *leader = event->group_leader; struct pmu_hw_events fake_pmu; + DECLARE_BITMAP(fake_used_mask, ARMPMU_MAX_HWEVENTS); - memset(&fake_pmu, 0, sizeof(fake_pmu)); + /* + * Initialise the fake PMU. We only need to populate the + * used_mask for the purposes of validation. + */ + memset(fake_used_mask, 0, sizeof(fake_used_mask)); + fake_pmu.used_mask = fake_used_mask; if (!validate_event(&fake_pmu, leader)) return -ENOSPC; From e5a21327644adba32816f74a415114d11c57f2e9 Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Tue, 22 Nov 2011 18:01:46 +0000 Subject: [PATCH 4/4] ARM: perf: check that we have a platform device when reserving PMU Attempting to use a hardware counter on a platform with a supported PMU but where the platform_device (defining the interrupts) has not been registered results in a NULL pointer dereference. This patch fixes the problem by checking that we actually have a platform device registered before attempting to grab the interrupts. Reported-by: Pawel Moll Signed-off-by: Will Deacon --- arch/arm/kernel/perf_event.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/arm/kernel/perf_event.c b/arch/arm/kernel/perf_event.c index e508066d3d64..c475379199b1 100644 --- a/arch/arm/kernel/perf_event.c +++ b/arch/arm/kernel/perf_event.c @@ -402,6 +402,9 @@ armpmu_reserve_hardware(struct arm_pmu *armpmu) int i, err, irq, irqs; struct platform_device *pmu_device = armpmu->plat_device; + if (!pmu_device) + return -ENODEV; + err = reserve_pmu(armpmu->type); if (err) { pr_warning("unable to reserve pmu\n");