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Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123// 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 <linux/uaccess.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;
if (!regs) { 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; regs->regs[22] = 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; }}
int arch_stack_walk_reliable(stack_trace_consume_fn consume_entry, void *cookie, struct task_struct *task){ unsigned long addr; struct pt_regs dummyregs; struct pt_regs *regs = &dummyregs; struct unwind_state state;
if (task == current) { regs->regs[3] = (unsigned long)__builtin_frame_address(0); regs->csr_era = (unsigned long)__builtin_return_address(0); regs->regs[22] = 0; } else { regs->regs[3] = thread_saved_fp(task); regs->csr_era = thread_saved_ra(task); regs->regs[22] = task->thread.reg22; } regs->regs[1] = 0;
for (unwind_start(&state, task, regs); !unwind_done(&state) && !unwind_error(&state); unwind_next_frame(&state)) { addr = unwind_get_return_address(&state);
/* * A NULL or invalid return address probably means there's some * generated code which __kernel_text_address() doesn't know about. */ if (!addr) return -EINVAL;
if (!consume_entry(cookie, addr)) return -EINVAL; }
/* Check for stack corruption */ if (unwind_error(&state)) return -EINVAL;
return 0;}
static intcopy_stack_frame(unsigned long fp, struct stack_frame *frame){ int ret = 1; unsigned long err; unsigned long __user *user_frame_tail;
user_frame_tail = (unsigned long *)(fp - sizeof(struct stack_frame)); if (!access_ok(user_frame_tail, sizeof(*frame))) return 0;
pagefault_disable(); err = (__copy_from_user_inatomic(frame, user_frame_tail, sizeof(*frame))); if (err || (unsigned long)user_frame_tail >= frame->fp) ret = 0; pagefault_enable();
return ret;}
void arch_stack_walk_user(stack_trace_consume_fn consume_entry, void *cookie, const struct pt_regs *regs){ unsigned long fp = regs->regs[22];
while (fp && !((unsigned long)fp & 0xf)) { struct stack_frame frame;
frame.fp = 0; frame.ra = 0; if (!copy_stack_frame(fp, &frame)) break; if (!frame.ra) break; if (!consume_entry(cookie, frame.ra)) break; fp = frame.fp; }}