mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-12-26 20:44:32 +08:00
222ee9087a
A comment in arch/s390/include/asm/unwind.h says: > If 'first_frame' is not zero unwind_start skips unwind frames until it > reaches the specified stack pointer. > The end of the unwinding is indicated with unwind_done, this can be true > right after unwind_start, e.g. with first_frame!=0 that can not be found. > unwind_next_frame skips to the next frame. > Once the unwind is completed unwind_error() can be used to check if there > has been a situation where the unwinder could not correctly understand > the tasks call chain. With this change backchain unwinder now comply with behaviour described. As well as matches orc unwinder implementation. Now unwinder starts from reliable state, i.e. __unwind_start own stack frame is taken or stack frame generated by __switch_to (ksp) - both known to be valid. In case of pt_regs %r15 is better match for pt_regs psw, than sometimes random "sp" caller passed. Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
84 lines
2.8 KiB
C
84 lines
2.8 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
|
|
#ifndef _ASM_S390_UNWIND_H
|
|
#define _ASM_S390_UNWIND_H
|
|
|
|
#include <linux/sched.h>
|
|
#include <linux/ftrace.h>
|
|
#include <asm/ptrace.h>
|
|
#include <asm/stacktrace.h>
|
|
|
|
/*
|
|
* To use the stack unwinder it has to be initialized with unwind_start.
|
|
* There four combinations for task and regs:
|
|
* 1) task==NULL, regs==NULL: the unwind starts for the task that is currently
|
|
* running, sp/ip picked up from the CPU registers
|
|
* 2) task==NULL, regs!=NULL: the unwind starts from the sp/ip found in
|
|
* the struct pt_regs of an interrupt frame for the current task
|
|
* 3) task!=NULL, regs==NULL: the unwind starts for an inactive task with
|
|
* the sp picked up from task->thread.ksp and the ip picked up from the
|
|
* return address stored by __switch_to
|
|
* 4) task!=NULL, regs!=NULL: the sp/ip are picked up from the interrupt
|
|
* frame 'regs' of a inactive task
|
|
* If 'first_frame' is not zero unwind_start skips unwind frames until it
|
|
* reaches the specified stack pointer.
|
|
* The end of the unwinding is indicated with unwind_done, this can be true
|
|
* right after unwind_start, e.g. with first_frame!=0 that can not be found.
|
|
* unwind_next_frame skips to the next frame.
|
|
* Once the unwind is completed unwind_error() can be used to check if there
|
|
* has been a situation where the unwinder could not correctly understand
|
|
* the tasks call chain.
|
|
*/
|
|
|
|
struct unwind_state {
|
|
struct stack_info stack_info;
|
|
unsigned long stack_mask;
|
|
struct task_struct *task;
|
|
struct pt_regs *regs;
|
|
unsigned long sp, ip;
|
|
int graph_idx;
|
|
bool reliable;
|
|
bool error;
|
|
};
|
|
|
|
void __unwind_start(struct unwind_state *state, struct task_struct *task,
|
|
struct pt_regs *regs, unsigned long first_frame);
|
|
bool unwind_next_frame(struct unwind_state *state);
|
|
unsigned long unwind_get_return_address(struct unwind_state *state);
|
|
|
|
static inline bool unwind_done(struct unwind_state *state)
|
|
{
|
|
return state->stack_info.type == STACK_TYPE_UNKNOWN;
|
|
}
|
|
|
|
static inline bool unwind_error(struct unwind_state *state)
|
|
{
|
|
return state->error;
|
|
}
|
|
|
|
static inline void unwind_start(struct unwind_state *state,
|
|
struct task_struct *task,
|
|
struct pt_regs *regs,
|
|
unsigned long first_frame)
|
|
{
|
|
task = task ?: current;
|
|
first_frame = first_frame ?: get_stack_pointer(task, regs);
|
|
__unwind_start(state, task, regs, first_frame);
|
|
}
|
|
|
|
static inline struct pt_regs *unwind_get_entry_regs(struct unwind_state *state)
|
|
{
|
|
return unwind_done(state) ? NULL : state->regs;
|
|
}
|
|
|
|
#define unwind_for_each_frame(state, task, regs, first_frame) \
|
|
for (unwind_start(state, task, regs, first_frame); \
|
|
!unwind_done(state); \
|
|
unwind_next_frame(state))
|
|
|
|
static inline void unwind_init(void) {}
|
|
static inline void unwind_module_init(struct module *mod, void *orc_ip,
|
|
size_t orc_ip_size, void *orc,
|
|
size_t orc_size) {}
|
|
|
|
#endif /* _ASM_S390_UNWIND_H */
|