Hi, > -----Original Message----- > From: madvenka@xxxxxxxxxxxxxxxxxxx <madvenka@xxxxxxxxxxxxxxxxxxx> > Sent: Friday, October 15, 2021 11:59 AM > To: mark.rutland@xxxxxxx; broonie@xxxxxxxxxx; jpoimboe@xxxxxxxxxx; ardb@xxxxxxxxxx; Nobuta, Keiya/信田 圭哉 > <nobuta.keiya@xxxxxxxxxxx>; sjitindarsingh@xxxxxxxxx; catalin.marinas@xxxxxxx; will@xxxxxxxxxx; jmorris@xxxxxxxxx; > linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; live-patching@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; > madvenka@xxxxxxxxxxxxxxxxxxx > Subject: [PATCH v10 06/11] arm64: Make profile_pc() use arch_stack_walk() > > From: "Madhavan T. Venkataraman" <madvenka@xxxxxxxxxxxxxxxxxxx> > > Currently, profile_pc() in ARM64 code walks the stack using > start_backtrace() and unwind_frame(). Make it use arch_stack_walk() instead. This makes maintenance easier. > > Signed-off-by: Madhavan T. Venkataraman <madvenka@xxxxxxxxxxxxxxxxxxx> > --- > arch/arm64/kernel/time.c | 22 +++++++++++++--------- > 1 file changed, 13 insertions(+), 9 deletions(-) > > diff --git a/arch/arm64/kernel/time.c b/arch/arm64/kernel/time.c index eebbc8d7123e..671b3038a772 100644 > --- a/arch/arm64/kernel/time.c > +++ b/arch/arm64/kernel/time.c > @@ -32,22 +32,26 @@ > #include <asm/stacktrace.h> > #include <asm/paravirt.h> > > +static bool profile_pc_cb(void *arg, unsigned long pc) { > + unsigned long *prof_pc = arg; > + > + if (in_lock_functions(pc)) > + return true; > + *prof_pc = pc; > + return false; > +} > + > unsigned long profile_pc(struct pt_regs *regs) { > - struct stackframe frame; > + unsigned long prof_pc = 0; > > if (!in_lock_functions(regs->pc)) > return regs->pc; > > - start_backtrace(&frame, regs->regs[29], regs->pc); > - > - do { > - int ret = unwind_frame(NULL, &frame); > - if (ret < 0) > - return 0; > - } while (in_lock_functions(frame.pc)); > + arch_stack_walk(profile_pc_cb, &prof_pc, current, regs); > > - return frame.pc; > + return prof_pc; > } > EXPORT_SYMBOL(profile_pc); > > -- > 2.25.1 I've got build error with CONFIG_ACPI=n: ==== arch/arm64/kernel/time.c: In function 'profile_pc': arch/arm64/kernel/time.c:52:2: error: implicit declaration of function 'arch_stack_walk' [-Werror=implicit-function-declaration] 52 | arch_stack_walk(profile_pc_cb, &prof_pc, current, regs); | ^~~~~~~~~~~~~~~ ==== I think it should include <linux/stacktrace.h> instead of <asm/stacktrace.h>. Thanks, Keiya