From 3e4196a5cc9cff50900f3dc8acc3d41e5963fd50 Mon Sep 17 00:00:00 2001 From: Max Filippov Date: Mon, 15 Apr 2013 09:20:48 +0400 Subject: [PATCH] xtensa: add stacktrace support Signed-off-by: Max Filippov Signed-off-by: Chris Zankel --- arch/xtensa/Kconfig | 3 + arch/xtensa/include/asm/stacktrace.h | 36 ++++++++++++ arch/xtensa/kernel/Makefile | 6 +- arch/xtensa/kernel/stacktrace.c | 87 ++++++++++++++++++++++++++++ arch/xtensa/kernel/traps.c | 49 ++++------------ 5 files changed, 140 insertions(+), 41 deletions(-) create mode 100644 arch/xtensa/include/asm/stacktrace.h create mode 100644 arch/xtensa/kernel/stacktrace.c diff --git a/arch/xtensa/Kconfig b/arch/xtensa/Kconfig index a9bdb1c5f13d..13280f2780c8 100644 --- a/arch/xtensa/Kconfig +++ b/arch/xtensa/Kconfig @@ -52,6 +52,9 @@ config HZ source "init/Kconfig" source "kernel/Kconfig.freezer" +config STACKTRACE_SUPPORT + def_bool y + config MMU def_bool n diff --git a/arch/xtensa/include/asm/stacktrace.h b/arch/xtensa/include/asm/stacktrace.h new file mode 100644 index 000000000000..6a05fcb0a20d --- /dev/null +++ b/arch/xtensa/include/asm/stacktrace.h @@ -0,0 +1,36 @@ +/* + * arch/xtensa/include/asm/stacktrace.h + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + * + * Copyright (C) 2001 - 2013 Tensilica Inc. + */ +#ifndef _XTENSA_STACKTRACE_H +#define _XTENSA_STACKTRACE_H + +#include + +struct stackframe { + unsigned long pc; + unsigned long sp; +}; + +static __always_inline unsigned long *stack_pointer(struct task_struct *task) +{ + unsigned long *sp; + + if (!task || task == current) + __asm__ __volatile__ ("mov %0, a1\n" : "=a"(sp)); + else + sp = (unsigned long *)task->thread.sp; + + return sp; +} + +void walk_stackframe(unsigned long *sp, + int (*fn)(struct stackframe *frame, void *data), + void *data); + +#endif /* _XTENSA_STACKTRACE_H */ diff --git a/arch/xtensa/kernel/Makefile b/arch/xtensa/kernel/Makefile index c433a56fbff9..1e7fc87a94bb 100644 --- a/arch/xtensa/kernel/Makefile +++ b/arch/xtensa/kernel/Makefile @@ -4,9 +4,9 @@ extra-y := head.o vmlinux.lds -obj-y := align.o entry.o irq.o coprocessor.o process.o ptrace.o \ - setup.o signal.o syscall.o time.o traps.o vectors.o platform.o \ - pci-dma.o +obj-y := align.o coprocessor.o entry.o irq.o pci-dma.o platform.o process.o \ + ptrace.o setup.o signal.o stacktrace.o syscall.o time.o traps.o \ + vectors.o obj-$(CONFIG_KGDB) += xtensa-stub.o obj-$(CONFIG_PCI) += pci.o diff --git a/arch/xtensa/kernel/stacktrace.c b/arch/xtensa/kernel/stacktrace.c new file mode 100644 index 000000000000..e3aff9575183 --- /dev/null +++ b/arch/xtensa/kernel/stacktrace.c @@ -0,0 +1,87 @@ +/* + * arch/xtensa/kernel/stacktrace.c + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + * + * Copyright (C) 2001 - 2013 Tensilica Inc. + */ +#include +#include +#include + +#include +#include + +void walk_stackframe(unsigned long *sp, + int (*fn)(struct stackframe *frame, void *data), + void *data) +{ + unsigned long a0, a1; + unsigned long sp_end; + + a1 = (unsigned long)sp; + sp_end = ALIGN(a1, THREAD_SIZE); + + spill_registers(); + + while (a1 < sp_end) { + struct stackframe frame; + + sp = (unsigned long *)a1; + + a0 = *(sp - 4); + a1 = *(sp - 3); + + if (a1 <= (unsigned long)sp) + break; + + frame.pc = MAKE_PC_FROM_RA(a0, a1); + frame.sp = a1; + + if (fn(&frame, data)) + return; + } +} + +#ifdef CONFIG_STACKTRACE + +struct stack_trace_data { + struct stack_trace *trace; + unsigned skip; +}; + +static int stack_trace_cb(struct stackframe *frame, void *data) +{ + struct stack_trace_data *trace_data = data; + struct stack_trace *trace = trace_data->trace; + + if (trace_data->skip) { + --trace_data->skip; + return 0; + } + if (!kernel_text_address(frame->pc)) + return 0; + + trace->entries[trace->nr_entries++] = frame->pc; + return trace->nr_entries >= trace->max_entries; +} + +void save_stack_trace_tsk(struct task_struct *task, struct stack_trace *trace) +{ + struct stack_trace_data trace_data = { + .trace = trace, + .skip = trace->skip, + }; + walk_stackframe(stack_pointer(task), stack_trace_cb, &trace_data); +} +EXPORT_SYMBOL_GPL(save_stack_trace_tsk); + +void save_stack_trace(struct stack_trace *trace) +{ + save_stack_trace_tsk(current, trace); +} +EXPORT_SYMBOL_GPL(save_stack_trace); + +#endif diff --git a/arch/xtensa/kernel/traps.c b/arch/xtensa/kernel/traps.c index 923db5c15278..cf065e165ceb 100644 --- a/arch/xtensa/kernel/traps.c +++ b/arch/xtensa/kernel/traps.c @@ -11,7 +11,7 @@ * * Essentially rewritten for the Xtensa architecture port. * - * Copyright (C) 2001 - 2005 Tensilica Inc. + * Copyright (C) 2001 - 2013 Tensilica Inc. * * Joe Taylor * Chris Zankel @@ -32,6 +32,7 @@ #include #include +#include #include #include #include @@ -402,53 +403,25 @@ void show_regs(struct pt_regs * regs) regs->syscall); } -static __always_inline unsigned long *stack_pointer(struct task_struct *task) +static int show_trace_cb(struct stackframe *frame, void *data) { - unsigned long *sp; - - if (!task || task == current) - __asm__ __volatile__ ("mov %0, a1\n" : "=a"(sp)); - else - sp = (unsigned long *)task->thread.sp; - - return sp; + if (kernel_text_address(frame->pc)) { + printk(" [<%08lx>] ", frame->pc); + print_symbol("%s\n", frame->pc); + } + return 0; } void show_trace(struct task_struct *task, unsigned long *sp) { - unsigned long a0, a1, pc; - unsigned long sp_start, sp_end; - - if (sp) - a1 = (unsigned long)sp; - else - a1 = (unsigned long)stack_pointer(task); - - sp_start = a1 & ~(THREAD_SIZE-1); - sp_end = sp_start + THREAD_SIZE; + if (!sp) + sp = stack_pointer(task); printk("Call Trace:"); #ifdef CONFIG_KALLSYMS printk("\n"); #endif - spill_registers(); - - while (a1 > sp_start && a1 < sp_end) { - sp = (unsigned long*)a1; - - a0 = *(sp - 4); - a1 = *(sp - 3); - - if (a1 <= (unsigned long) sp) - break; - - pc = MAKE_PC_FROM_RA(a0, a1); - - if (kernel_text_address(pc)) { - printk(" [<%08lx>] ", pc); - print_symbol("%s\n", pc); - } - } + walk_stackframe(sp, show_trace_cb, NULL); printk("\n"); } -- 2.20.1