From: Li RongQing Date: Tue, 16 Jun 2026 07:26:17 +0000 (+0800) Subject: ACPI: processor_idle: Mark LPI enter functions as __cpuidle X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=956ca5d72c76504824c8eb601879da9476973e15;p=thirdparty%2Fkernel%2Flinux.git ACPI: processor_idle: Mark LPI enter functions as __cpuidle When function tracing or Kprobes is enabled, entering an ACPI Low Power Idle (LPI) state triggers the following RCU splat: RCU not on for: acpi_idle_lpi_enter+0x4/0xd8 WARNING: CPU: 8 PID: 0 at include/linux/trace_recursion.h:162 function_trace_call+0x1e8/0x228 The acpi_idle_lpi_enter() function is invoked within the cpuidle path after RCU has already been disabled for the current local CPU. Consequently, ftrace's function_trace_call() expects RCU to be actively watching before recording trace data, emitting a warning if it is not. Fix this by annotating acpi_idle_lpi_enter(), the generic __weak stub, and the RISC-V implementation of acpi_processor_ffh_lpi_enter() with __cpuidle. This moves these functions into the '.cpuidle.text' section, implicitly disabling ftrace instrumentation (notrace) along this sensitive path and preventing trace-induced RCU warnings during idle entry. Fixes: a36a7fecfe60 ("ACPI / processor_idle: Add support for Low Power Idle(LPI) states") Signed-off-by: Li RongQing Acked-by: lihuisong@huawei.com Link: https://patch.msgid.link/20260616072617.2272-1-lirongqing@baidu.com Signed-off-by: Rafael J. Wysocki --- diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c index 390ab5f1d3137..4482cf28f56ae 100644 --- a/drivers/acpi/processor_idle.c +++ b/drivers/acpi/processor_idle.c @@ -1143,7 +1143,7 @@ static int acpi_processor_get_lpi_info(struct acpi_processor *pr) return 0; } -int __weak acpi_processor_ffh_lpi_enter(struct acpi_lpi_state *lpi) +int __weak __cpuidle acpi_processor_ffh_lpi_enter(struct acpi_lpi_state *lpi) { return -ENODEV; } @@ -1156,7 +1156,7 @@ int __weak acpi_processor_ffh_lpi_enter(struct acpi_lpi_state *lpi) * * Return: 0 for success or negative value for error */ -static int acpi_idle_lpi_enter(struct cpuidle_device *dev, +static int __cpuidle acpi_idle_lpi_enter(struct cpuidle_device *dev, struct cpuidle_driver *drv, int index) { struct acpi_processor *pr; diff --git a/drivers/acpi/riscv/cpuidle.c b/drivers/acpi/riscv/cpuidle.c index 624f9bbdb58c4..c76dbabff702e 100644 --- a/drivers/acpi/riscv/cpuidle.c +++ b/drivers/acpi/riscv/cpuidle.c @@ -66,7 +66,7 @@ int acpi_processor_ffh_lpi_probe(unsigned int cpu) return acpi_cpu_init_idle(cpu); } -int acpi_processor_ffh_lpi_enter(struct acpi_lpi_state *lpi) +int __cpuidle acpi_processor_ffh_lpi_enter(struct acpi_lpi_state *lpi) { u32 state = lpi->address;