Qing Zhang 93a4fa622e LoongArch: Add STACKTRACE support
1. Use common arch_stack_walk() infrastructure to avoid duplicated code
   and avoid taking care of the stack storage and filtering.
2. Add sched_ra (means sched return address) and sched_cfa (means sched
   call frame address) to thread_info, and store them in switch_to().
3. Add __get_wchan() implementation.

Now we can print the process stack and wait channel by cat /proc/*/stack
and /proc/*/wchan.

Signed-off-by: Qing Zhang <zhangqing@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2022-08-12 13:10:11 +08:00

38 lines
946 B
C

// SPDX-License-Identifier: GPL-2.0
/*
* Stack trace management functions
*
* Copyright (C) 2022 Loongson Technology Corporation Limited
*/
#include <linux/sched.h>
#include <linux/stacktrace.h>
#include <asm/stacktrace.h>
#include <asm/unwind.h>
void arch_stack_walk(stack_trace_consume_fn consume_entry, void *cookie,
struct task_struct *task, struct pt_regs *regs)
{
unsigned long addr;
struct pt_regs dummyregs;
struct unwind_state state;
regs = &dummyregs;
if (task == current) {
regs->regs[3] = (unsigned long)__builtin_frame_address(0);
regs->csr_era = (unsigned long)__builtin_return_address(0);
} else {
regs->regs[3] = thread_saved_fp(task);
regs->csr_era = thread_saved_ra(task);
}
regs->regs[1] = 0;
for (unwind_start(&state, task, regs);
!unwind_done(&state); unwind_next_frame(&state)) {
addr = unwind_get_return_address(&state);
if (!addr || !consume_entry(cookie, addr))
break;
}
}