Commit | Line | Data |
---|---|---|
457c8996 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
7c7900f8 JP |
2 | #include <linux/sched.h> |
3 | #include <linux/ftrace.h> | |
4 | #include <asm/ptrace.h> | |
5 | #include <asm/bitops.h> | |
6 | #include <asm/stacktrace.h> | |
7 | #include <asm/unwind.h> | |
8 | ||
cfee9edd JP |
9 | unsigned long unwind_get_return_address(struct unwind_state *state) |
10 | { | |
55f856e6 | 11 | unsigned long addr; |
c2d75e03 | 12 | |
cfee9edd JP |
13 | if (unwind_done(state)) |
14 | return 0; | |
15 | ||
55f856e6 JP |
16 | addr = READ_ONCE_NOCHECK(*state->sp); |
17 | ||
cfee9edd | 18 | return ftrace_graph_ret_addr(state->task, &state->graph_idx, |
c2d75e03 | 19 | addr, state->sp); |
cfee9edd JP |
20 | } |
21 | EXPORT_SYMBOL_GPL(unwind_get_return_address); | |
22 | ||
ee9f8fce JP |
23 | unsigned long *unwind_get_return_address_ptr(struct unwind_state *state) |
24 | { | |
25 | return NULL; | |
26 | } | |
27 | ||
7c7900f8 JP |
28 | bool unwind_next_frame(struct unwind_state *state) |
29 | { | |
30 | struct stack_info *info = &state->stack_info; | |
31 | ||
32 | if (unwind_done(state)) | |
33 | return false; | |
34 | ||
35 | do { | |
55f856e6 JP |
36 | for (state->sp++; state->sp < info->end; state->sp++) { |
37 | unsigned long addr = READ_ONCE_NOCHECK(*state->sp); | |
c2d75e03 | 38 | |
c2d75e03 | 39 | if (__kernel_text_address(addr)) |
7c7900f8 | 40 | return true; |
55f856e6 | 41 | } |
7c7900f8 | 42 | |
e335bb51 | 43 | state->sp = PTR_ALIGN(info->next_sp, sizeof(long)); |
7c7900f8 JP |
44 | |
45 | } while (!get_stack_info(state->sp, state->task, info, | |
46 | &state->stack_mask)); | |
47 | ||
48 | return false; | |
49 | } | |
50 | EXPORT_SYMBOL_GPL(unwind_next_frame); | |
51 | ||
52 | void __unwind_start(struct unwind_state *state, struct task_struct *task, | |
53 | struct pt_regs *regs, unsigned long *first_frame) | |
54 | { | |
55 | memset(state, 0, sizeof(*state)); | |
56 | ||
57 | state->task = task; | |
e335bb51 | 58 | state->sp = PTR_ALIGN(first_frame, sizeof(long)); |
7c7900f8 JP |
59 | |
60 | get_stack_info(first_frame, state->task, &state->stack_info, | |
61 | &state->stack_mask); | |
62 | ||
7fbe6ac0 JP |
63 | /* |
64 | * The caller can provide the address of the first frame directly | |
65 | * (first_frame) or indirectly (regs->sp) to indicate which stack frame | |
66 | * to start unwinding at. Skip ahead until we reach it. | |
67 | */ | |
68 | if (!unwind_done(state) && | |
69 | (!on_stack(&state->stack_info, first_frame, sizeof(long)) || | |
70 | !__kernel_text_address(*first_frame))) | |
7c7900f8 JP |
71 | unwind_next_frame(state); |
72 | } | |
73 | EXPORT_SYMBOL_GPL(__unwind_start); |