6.6-stable review patch. If anyone has any objections, please let me know.
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From: Anand Moon linux.amoon@gmail.com
[ Upstream commit 097469a2b0f12b91b4f27b9e9e4f2c46484cde30 ]
The Amlogic DDR PMU driver meson_ddr_pmu_create() function incorrectly uses smp_processor_id(), which assumes disabled preemption. This leads to kernel warnings during module loading because meson_ddr_pmu_create() can be called in a preemptible context.
Following kernel warning and stack trace: [ 31.745138] [ T2289] BUG: using smp_processor_id() in preemptible [00000000] code: (udev-worker)/2289 [ 31.745154] [ T2289] caller is debug_smp_processor_id+0x28/0x38 [ 31.745172] [ T2289] CPU: 4 UID: 0 PID: 2289 Comm: (udev-worker) Tainted: GW 6.14.0-0-MANJARO-ARM #1 59519addcbca6ba8de735e151fd7b9e97aac7ff0 [ 31.745181] [ T2289] Tainted: [W]=WARN [ 31.745183] [ T2289] Hardware name: Hardkernel ODROID-N2Plus (DT) [ 31.745188] [ T2289] Call trace: [ 31.745191] [ T2289] show_stack+0x28/0x40 (C) [ 31.745199] [ T2289] dump_stack_lvl+0x4c/0x198 [ 31.745205] [ T2289] dump_stack+0x20/0x50 [ 31.745209] [ T2289] check_preemption_disabled+0xec/0xf0 [ 31.745213] [ T2289] debug_smp_processor_id+0x28/0x38 [ 31.745216] [ T2289] meson_ddr_pmu_create+0x200/0x560 [meson_ddr_pmu_g12 8095101c49676ad138d9961e3eddaee10acca7bd] [ 31.745237] [ T2289] g12_ddr_pmu_probe+0x20/0x38 [meson_ddr_pmu_g12 8095101c49676ad138d9961e3eddaee10acca7bd] [ 31.745246] [ T2289] platform_probe+0x98/0xe0 [ 31.745254] [ T2289] really_probe+0x144/0x3f8 [ 31.745258] [ T2289] __driver_probe_device+0xb8/0x180 [ 31.745261] [ T2289] driver_probe_device+0x54/0x268 [ 31.745264] [ T2289] __driver_attach+0x11c/0x288 [ 31.745267] [ T2289] bus_for_each_dev+0xfc/0x160 [ 31.745274] [ T2289] driver_attach+0x34/0x50 [ 31.745277] [ T2289] bus_add_driver+0x160/0x2b0 [ 31.745281] [ T2289] driver_register+0x78/0x120 [ 31.745285] [ T2289] __platform_driver_register+0x30/0x48 [ 31.745288] [ T2289] init_module+0x30/0xfe0 [meson_ddr_pmu_g12 8095101c49676ad138d9961e3eddaee10acca7bd] [ 31.745298] [ T2289] do_one_initcall+0x11c/0x438 [ 31.745303] [ T2289] do_init_module+0x68/0x228 [ 31.745311] [ T2289] load_module+0x118c/0x13a8 [ 31.745315] [ T2289] __arm64_sys_finit_module+0x274/0x390 [ 31.745320] [ T2289] invoke_syscall+0x74/0x108 [ 31.745326] [ T2289] el0_svc_common+0x90/0xf8 [ 31.745330] [ T2289] do_el0_svc+0x2c/0x48 [ 31.745333] [ T2289] el0_svc+0x60/0x150 [ 31.745337] [ T2289] el0t_64_sync_handler+0x80/0x118 [ 31.745341] [ T2289] el0t_64_sync+0x1b8/0x1c0
Changes replaces smp_processor_id() with raw_smp_processor_id() to ensure safe CPU ID retrieval in preemptible contexts.
Cc: Jiucheng Xu jiucheng.xu@amlogic.com Fixes: 2016e2113d35 ("perf/amlogic: Add support for Amlogic meson G12 SoC DDR PMU driver") Signed-off-by: Anand Moon linux.amoon@gmail.com Link: https://lore.kernel.org/r/20250407063206.5211-1-linux.amoon@gmail.com Signed-off-by: Will Deacon will@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/perf/amlogic/meson_ddr_pmu_core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/perf/amlogic/meson_ddr_pmu_core.c b/drivers/perf/amlogic/meson_ddr_pmu_core.c index bbc7285fd934a..5f8699612a9ad 100644 --- a/drivers/perf/amlogic/meson_ddr_pmu_core.c +++ b/drivers/perf/amlogic/meson_ddr_pmu_core.c @@ -510,7 +510,7 @@ int meson_ddr_pmu_create(struct platform_device *pdev)
fmt_attr_fill(pmu->info.hw_info->fmt_attr);
- pmu->cpu = smp_processor_id(); + pmu->cpu = raw_smp_processor_id();
name = devm_kasprintf(&pdev->dev, GFP_KERNEL, DDR_PERF_DEV_NAME); if (!name)