From efe9711214e6138a5a2a46ca4068bfce50c03444 Mon Sep 17 00:00:00 2001 From: Neal Liu Date: Mon, 27 Jul 2020 11:25:46 +0800 Subject: cpuidle: change enter_s2idle() prototype Control Flow Integrity(CFI) is a security mechanism that disallows changes to the original control flow graph of a compiled binary, making it significantly harder to perform such attacks. init_state_node() assign same function callback to different function pointer declarations. static int init_state_node(struct cpuidle_state *idle_state, const struct of_device_id *matches, struct device_node *state_node) { ... idle_state->enter = match_id->data; ... idle_state->enter_s2idle = match_id->data; } Function declarations: struct cpuidle_state { ... int (*enter) (struct cpuidle_device *dev, struct cpuidle_driver *drv, int index); void (*enter_s2idle) (struct cpuidle_device *dev, struct cpuidle_driver *drv, int index); }; In this case, either enter() or enter_s2idle() would cause CFI check failed since they use same callee. Align function prototype of enter() since it needs return value for some use cases. The return value of enter_s2idle() is no need currently. Signed-off-by: Neal Liu Reviewed-by: Sami Tolvanen Signed-off-by: Rafael J. Wysocki --- drivers/acpi/processor_idle.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'drivers/acpi') diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c index 75534c5b5433..6ffb6c99c2de 100644 --- a/drivers/acpi/processor_idle.c +++ b/drivers/acpi/processor_idle.c @@ -655,8 +655,8 @@ static int acpi_idle_enter(struct cpuidle_device *dev, return index; } -static void acpi_idle_enter_s2idle(struct cpuidle_device *dev, - struct cpuidle_driver *drv, int index) +static int acpi_idle_enter_s2idle(struct cpuidle_device *dev, + struct cpuidle_driver *drv, int index) { struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu); @@ -674,6 +674,8 @@ static void acpi_idle_enter_s2idle(struct cpuidle_device *dev, } } acpi_idle_do_entry(cx); + + return 0; } static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr, -- cgit v1.2.3 From 0a398945d6f3e54f9f88ba2a17908674c659bfa4 Mon Sep 17 00:00:00 2001 From: Neal Liu Date: Fri, 31 Jul 2020 11:39:04 +0800 Subject: cpuidle: ACPI: fix 'return' with no value build warning Add return value to fix return-type build warning introduced by commit efe9711214e6 ("cpuidle: change enter_s2idle() prototype"). Fixes: efe9711214e6 ("cpuidle: change enter_s2idle() prototype") Signed-off-by: Neal Liu [ rjw: Subject & changelog edits, make acpi_idle_enter_s2idle() return 0 in all cases ] Signed-off-by: Rafael J. Wysocki --- drivers/acpi/processor_idle.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'drivers/acpi') diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c index 6ffb6c99c2de..0c65a09aec1b 100644 --- a/drivers/acpi/processor_idle.c +++ b/drivers/acpi/processor_idle.c @@ -664,11 +664,11 @@ static int acpi_idle_enter_s2idle(struct cpuidle_device *dev, struct acpi_processor *pr = __this_cpu_read(processors); if (unlikely(!pr)) - return; + return 0; if (pr->flags.bm_check) { acpi_idle_enter_bm(pr, cx, false); - return; + return 0; } else { ACPI_FLUSH_CPU_CACHE(); } -- cgit v1.2.3