From 78c98f9074135d3dab4e39544e0a537f92388fce Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky Date: Mon, 28 Jan 2019 08:33:08 +0100 Subject: s390/unwind: introduce stack unwind API Rework the dump_trace() stack unwinder interface to support different unwinding algorithms. The new interface looks like this: struct unwind_state state; unwind_for_each_frame(&state, task, regs, start_stack) do_something(state.sp, state.ip, state.reliable); The unwind_bc.c file contains the implementation for the classic back-chain unwinder. One positive side effect of the new code is it now handles ftraced functions gracefully. It prints the real name of the return function instead of 'return_to_handler'. Signed-off-by: Martin Schwidefsky --- arch/s390/include/asm/stacktrace.h | 114 +++++++++++++++++++++++++++++++++++++ 1 file changed, 114 insertions(+) create mode 100644 arch/s390/include/asm/stacktrace.h (limited to 'arch/s390/include/asm/stacktrace.h') diff --git a/arch/s390/include/asm/stacktrace.h b/arch/s390/include/asm/stacktrace.h new file mode 100644 index 000000000000..49634bfbecdd --- /dev/null +++ b/arch/s390/include/asm/stacktrace.h @@ -0,0 +1,114 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_S390_STACKTRACE_H +#define _ASM_S390_STACKTRACE_H + +#include +#include +#include + +enum stack_type { + STACK_TYPE_UNKNOWN, + STACK_TYPE_TASK, + STACK_TYPE_IRQ, + STACK_TYPE_NODAT, + STACK_TYPE_RESTART, +}; + +struct stack_info { + enum stack_type type; + unsigned long begin, end; +}; + +const char *stack_type_name(enum stack_type type); +int get_stack_info(unsigned long sp, struct task_struct *task, + struct stack_info *info, unsigned long *visit_mask); + +static inline bool on_stack(struct stack_info *info, + unsigned long addr, size_t len) +{ + if (info->type == STACK_TYPE_UNKNOWN) + return false; + if (addr + len < addr) + return false; + return addr >= info->begin && addr + len < info->end; +} + +static inline unsigned long get_stack_pointer(struct task_struct *task, + struct pt_regs *regs) +{ + if (regs) + return (unsigned long) kernel_stack_pointer(regs); + if (task == current) + return current_stack_pointer(); + return (unsigned long) task->thread.ksp; +} + +/* + * Stack layout of a C stack frame. + */ +#ifndef __PACK_STACK +struct stack_frame { + unsigned long back_chain; + unsigned long empty1[5]; + unsigned long gprs[10]; + unsigned int empty2[8]; +}; +#else +struct stack_frame { + unsigned long empty1[5]; + unsigned int empty2[8]; + unsigned long gprs[10]; + unsigned long back_chain; +}; +#endif + +#define CALL_ARGS_0() \ + register unsigned long r2 asm("2") +#define CALL_ARGS_1(arg1) \ + register unsigned long r2 asm("2") = (unsigned long)(arg1) +#define CALL_ARGS_2(arg1, arg2) \ + CALL_ARGS_1(arg1); \ + register unsigned long r3 asm("3") = (unsigned long)(arg2) +#define CALL_ARGS_3(arg1, arg2, arg3) \ + CALL_ARGS_2(arg1, arg2); \ + register unsigned long r4 asm("4") = (unsigned long)(arg3) +#define CALL_ARGS_4(arg1, arg2, arg3, arg4) \ + CALL_ARGS_3(arg1, arg2, arg3); \ + register unsigned long r4 asm("5") = (unsigned long)(arg4) +#define CALL_ARGS_5(arg1, arg2, arg3, arg4, arg5) \ + CALL_ARGS_4(arg1, arg2, arg3, arg4); \ + register unsigned long r4 asm("6") = (unsigned long)(arg5) + +#define CALL_FMT_0 "=&d" (r2) : +#define CALL_FMT_1 "+&d" (r2) : +#define CALL_FMT_2 CALL_FMT_1 "d" (r3), +#define CALL_FMT_3 CALL_FMT_2 "d" (r4), +#define CALL_FMT_4 CALL_FMT_3 "d" (r5), +#define CALL_FMT_5 CALL_FMT_4 "d" (r6), + +#define CALL_CLOBBER_5 "0", "1", "14", "cc", "memory" +#define CALL_CLOBBER_4 CALL_CLOBBER_5 +#define CALL_CLOBBER_3 CALL_CLOBBER_4, "5" +#define CALL_CLOBBER_2 CALL_CLOBBER_3, "4" +#define CALL_CLOBBER_1 CALL_CLOBBER_2, "3" +#define CALL_CLOBBER_0 CALL_CLOBBER_1 + +#define CALL_ON_STACK(fn, stack, nr, args...) \ +({ \ + CALL_ARGS_##nr(args); \ + unsigned long prev; \ + \ + asm volatile( \ + " la %[_prev],0(15)\n" \ + " la 15,0(%[_stack])\n" \ + " stg %[_prev],%[_bc](15)\n" \ + " brasl 14,%[_fn]\n" \ + " la 15,0(%[_prev])\n" \ + : [_prev] "=&a" (prev), CALL_FMT_##nr \ + [_stack] "a" (stack), \ + [_bc] "i" (offsetof(struct stack_frame, back_chain)), \ + [_fn] "X" (fn) : CALL_CLOBBER_##nr); \ + r2; \ +}) + +#endif /* _ASM_S390_STACKTRACE_H */ -- cgit v1.2.3-59-g8ed1b