From 752ec621ef5c30777958cc5eb5f1cf394f7733f4 Mon Sep 17 00:00:00 2001 From: Li Huafei Date: Fri, 26 Aug 2022 09:08:46 +0100 Subject: ARM: 9234/1: stacktrace: Avoid duplicate saving of exception PC value Because an exception stack frame is not created in the exception entry, save_trace() does special handling for the exception PC, but this is only needed when CONFIG_FRAME_POINTER_UNWIND=y. When CONFIG_ARM_UNWIND=y, unwind annotations have been added to the exception entry and save_trace() will repeatedly save the exception PC: [0x7f000090] hrtimer_hander+0x8/0x10 [hrtimer] [0x8019ec50] __hrtimer_run_queues+0x18c/0x394 [0x8019f760] hrtimer_run_queues+0xbc/0xd0 [0x8019def0] update_process_times+0x34/0x80 [0x801ad2a4] tick_periodic+0x48/0xd0 [0x801ad3dc] tick_handle_periodic+0x1c/0x7c [0x8010f2e0] twd_handler+0x30/0x40 [0x80177620] handle_percpu_devid_irq+0xa0/0x23c [0x801718d0] generic_handle_domain_irq+0x24/0x34 [0x80502d28] gic_handle_irq+0x74/0x88 [0x8085817c] generic_handle_arch_irq+0x58/0x78 [0x80100ba8] __irq_svc+0x88/0xc8 [0x80108114] arch_cpu_idle+0x38/0x3c [0x80108114] arch_cpu_idle+0x38/0x3c <==== duplicate saved exception PC [0x80861bf8] default_idle_call+0x38/0x130 [0x8015d5cc] do_idle+0x150/0x214 [0x8015d978] cpu_startup_entry+0x18/0x1c [0x808589c0] rest_init+0xd8/0xdc [0x80c00a44] arch_post_acpi_subsys_init+0x0/0x8 We can move the special handling of the exception PC in save_trace() to the unwind_frame() of the frame pointer unwinder. Signed-off-by: Li Huafei Reviewed-by: Linus Waleij Signed-off-by: Russell King (Oracle) --- arch/arm/include/asm/stacktrace.h | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'arch/arm/include/asm') diff --git a/arch/arm/include/asm/stacktrace.h b/arch/arm/include/asm/stacktrace.h index dd19a46f781a..36b2ff44fcbb 100644 --- a/arch/arm/include/asm/stacktrace.h +++ b/arch/arm/include/asm/stacktrace.h @@ -21,6 +21,9 @@ struct stackframe { struct llist_node *kr_cur; struct task_struct *tsk; #endif +#ifdef CONFIG_UNWINDER_FRAME_POINTER + bool ex_frame; +#endif }; static __always_inline @@ -34,6 +37,9 @@ void arm_get_current_stackframe(struct pt_regs *regs, struct stackframe *frame) frame->kr_cur = NULL; frame->tsk = current; #endif +#ifdef CONFIG_UNWINDER_FRAME_POINTER + frame->ex_frame = in_entry_text(frame->pc); +#endif } extern int unwind_frame(struct stackframe *frame); -- cgit v1.2.3-59-g8ed1b