drivers/perf: Fix kernel panic when rmmod PMU modules during perf sampling

When users try to remove PMU modules during perf sampling, kernel panic
will happen because the pmu->read() is a NULL pointer here.

INFO on HiSilicon hip08 platform as follow:
pc : hisi_uncore_pmu_event_update+0x30/0xa4 [hisi_uncore_pmu]
lr : hisi_uncore_pmu_read+0x20/0x2c [hisi_uncore_pmu]
sp : ffff800010103e90
x29: ffff800010103e90 x28: ffff0027db0c0e40
x27: ffffa29a76f129d8 x26: ffffa29a77ceb000
x25: ffffa29a773a5000 x24: ffffa29a77392000
x23: ffffddffe5943f08 x22: ffff002784285960
x21: ffff002784285800 x20: ffff0027d2e76c80
x19: ffff0027842859e0 x18: ffff80003498bcc8
x17: ffffa29a76afe910 x16: ffffa29a7583f530
x15: 16151a1512061a1e x14: 0000000000000000
x13: ffffa29a76f1e238 x12: 0000000000000001
x11: 0000000000000400 x10: 00000000000009f0
x9 : ffff8000107b3e70 x8 : ffff0027db0c1890
x7 : ffffa29a773a7000 x6 : 00000007f5131013
x5 : 00000007f5131013 x4 : 09f257d417c00000
x3 : 00000002187bd7ce x2 : ffffa29a38f0f0d8
x1 : ffffa29a38eae268 x0 : ffff0027d2e76c80
Call trace:
hisi_uncore_pmu_event_update+0x30/0xa4 [hisi_uncore_pmu]
hisi_uncore_pmu_read+0x20/0x2c [hisi_uncore_pmu]
__perf_event_read+0x1a0/0x1f8
flush_smp_call_function_queue+0xa0/0x160
generic_smp_call_function_single_interrupt+0x18/0x20
handle_IPI+0x31c/0x4dc
gic_handle_irq+0x2c8/0x310
el1_irq+0xcc/0x180
arch_cpu_idle+0x4c/0x20c
default_idle_call+0x20/0x30
do_idle+0x1b4/0x270
cpu_startup_entry+0x28/0x30
secondary_start_kernel+0x1a4/0x1fc

To solve the above issue, current module should be registered to kernel,
so that try_module_get() can be invoked when perf sampling starts. This
adds the reference counting of module and could prevent users from removing
modules during sampling.

Reported-by: Haifeng Wang <wang.wanghaifeng@huawei.com>
Signed-off-by: Qi Liu <liuqi115@huawei.com>
Reviewed-by: John Garry <john.garry@huawei.com>
Link: https://lore.kernel.org/r/1594891165-8228-1-git-send-email-liuqi115@huawei.com
Signed-off-by: Will Deacon <will@kernel.org>

diff --git a/drivers/perf/arm_smmuv3_pmu.c b/drivers/perf/arm_smmuv3_pmu.c
index 48e28ef93a7022f21258016d2c4a1cf109dc1539..90caba56dfbc141efb8b84759256705238b67f11 100644 (file)
--- a/drivers/perf/arm_smmuv3_pmu.c
+++ b/drivers/perf/arm_smmuv3_pmu.c
@@ -742,6 +742,7 @@ static int smmu_pmu_probe(struct platform_device *pdev)
        platform_set_drvdata(pdev, smmu_pmu);
 
        smmu_pmu->pmu = (struct pmu) {
+               .module         = THIS_MODULE,
                .task_ctx_nr    = perf_invalid_context,
                .pmu_enable     = smmu_pmu_enable,
                .pmu_disable    = smmu_pmu_disable,

diff --git a/drivers/perf/fsl_imx8_ddr_perf.c b/drivers/perf/fsl_imx8_ddr_perf.c
index 90884d14f95faea01082bfd82c587ecedbd31667..2aed2d96f8ae70b29c8df0d2a8bb8ec664a00247 100644 (file)
--- a/drivers/perf/fsl_imx8_ddr_perf.c
+++ b/drivers/perf/fsl_imx8_ddr_perf.c
@@ -512,6 +512,7 @@ static int ddr_perf_init(struct ddr_pmu *pmu, void __iomem *base,
 {
        *pmu = (struct ddr_pmu) {
                .pmu = (struct pmu) {
+                       .module       = THIS_MODULE,
                        .capabilities = PERF_PMU_CAP_NO_EXCLUDE,
                        .task_ctx_nr = perf_invalid_context,
                        .attr_groups = attr_groups,

diff --git a/drivers/perf/hisilicon/hisi_uncore_ddrc_pmu.c b/drivers/perf/hisilicon/hisi_uncore_ddrc_pmu.c
index 15713faaa07e77eeed9dbc5333f2bf77c228d924..71587f19fcd500d76eb370da4816acca532bf922 100644 (file)
--- a/drivers/perf/hisilicon/hisi_uncore_ddrc_pmu.c
+++ b/drivers/perf/hisilicon/hisi_uncore_ddrc_pmu.c
@@ -378,6 +378,7 @@ static int hisi_ddrc_pmu_probe(struct platform_device *pdev)
                              ddrc_pmu->sccl_id, ddrc_pmu->index_id);
        ddrc_pmu->pmu = (struct pmu) {
                .name           = name,
+               .module         = THIS_MODULE,
                .task_ctx_nr    = perf_invalid_context,
                .event_init     = hisi_uncore_pmu_event_init,
                .pmu_enable     = hisi_uncore_pmu_enable,

diff --git a/drivers/perf/hisilicon/hisi_uncore_hha_pmu.c b/drivers/perf/hisilicon/hisi_uncore_hha_pmu.c
index dcc5600788a9a271a2adaec47fa84703ec78fbfc..c199de7b219dd34ece30434c6b06597b1f53d86c 100644 (file)
--- a/drivers/perf/hisilicon/hisi_uncore_hha_pmu.c
+++ b/drivers/perf/hisilicon/hisi_uncore_hha_pmu.c
@@ -390,6 +390,7 @@ static int hisi_hha_pmu_probe(struct platform_device *pdev)
                              hha_pmu->sccl_id, hha_pmu->index_id);
        hha_pmu->pmu = (struct pmu) {
                .name           = name,
+               .module         = THIS_MODULE,
                .task_ctx_nr    = perf_invalid_context,
                .event_init     = hisi_uncore_pmu_event_init,
                .pmu_enable     = hisi_uncore_pmu_enable,

diff --git a/drivers/perf/hisilicon/hisi_uncore_l3c_pmu.c b/drivers/perf/hisilicon/hisi_uncore_l3c_pmu.c
index 7719ae4e2c561468a08c1c0a50d4e2fba411bac0..567d7e6f69d8122231e83f9ee6f1c4a0c7dab431 100644 (file)
--- a/drivers/perf/hisilicon/hisi_uncore_l3c_pmu.c
+++ b/drivers/perf/hisilicon/hisi_uncore_l3c_pmu.c
@@ -380,6 +380,7 @@ static int hisi_l3c_pmu_probe(struct platform_device *pdev)
                              l3c_pmu->sccl_id, l3c_pmu->index_id);
        l3c_pmu->pmu = (struct pmu) {
                .name           = name,
+               .module         = THIS_MODULE,
                .task_ctx_nr    = perf_invalid_context,
                .event_init     = hisi_uncore_pmu_event_init,
                .pmu_enable     = hisi_uncore_pmu_enable,