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Message-ID: <20250407063206.5211-1-linux.amoon@gmail.com>
Date: Mon, 7 Apr 2025 12:02:03 +0530
From: Anand Moon <linux.amoon@...il.com>
To: Jiucheng Xu <jiucheng.xu@...ogic.com>,
Will Deacon <will@...nel.org>,
Mark Rutland <mark.rutland@....com>,
Neil Armstrong <neil.armstrong@...aro.org>,
Kevin Hilman <khilman@...libre.com>,
Jerome Brunet <jbrunet@...libre.com>,
Martin Blumenstingl <martin.blumenstingl@...glemail.com>,
linux-amlogic@...ts.infradead.org (open list:AMLOGIC DDR PMU DRIVER),
linux-arm-kernel@...ts.infradead.org (moderated list:ARM PMU PROFILING AND DEBUGGING),
linux-perf-users@...r.kernel.org (open list:ARM PMU PROFILING AND DEBUGGING),
linux-kernel@...r.kernel.org (open list)
Cc: Anand Moon <linux.amoon@...il.com>
Subject: [PATCH v1] perf/amlogic: Replace smp_processor_id() with raw_smp_processor_id() in meson_ddr_pmu_create()
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@...ogic.com>
Fixes: 2016e2113d35 ("perf/amlogic: Add support for Amlogic meson G12 SoC DDR PMU driver")
Signed-off-by: Anand Moon <linux.amoon@...il.com>
---
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 07446d784a1a..c1e755c356a3 100644
--- a/drivers/perf/amlogic/meson_ddr_pmu_core.c
+++ b/drivers/perf/amlogic/meson_ddr_pmu_core.c
@@ -511,7 +511,7 @@ 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)
base-commit: 0af2f6be1b4281385b618cb86ad946eded089ac8
--
2.49.0
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