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Commit | Line | Data |
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7c7900f8 JP |
1 | #include <linux/sched.h> |
2 | #include <linux/ftrace.h> | |
3 | #include <asm/ptrace.h> | |
4 | #include <asm/bitops.h> | |
5 | #include <asm/stacktrace.h> | |
6 | #include <asm/unwind.h> | |
7 | ||
cfee9edd JP |
8 | unsigned long unwind_get_return_address(struct unwind_state *state) |
9 | { | |
55f856e6 | 10 | unsigned long addr; |
c2d75e03 | 11 | |
cfee9edd JP |
12 | if (unwind_done(state)) |
13 | return 0; | |
14 | ||
55f856e6 JP |
15 | addr = READ_ONCE_NOCHECK(*state->sp); |
16 | ||
cfee9edd | 17 | return ftrace_graph_ret_addr(state->task, &state->graph_idx, |
c2d75e03 | 18 | addr, state->sp); |
cfee9edd JP |
19 | } |
20 | EXPORT_SYMBOL_GPL(unwind_get_return_address); | |
21 | ||
dccbf63d JP |
22 | unsigned long *unwind_get_return_address_ptr(struct unwind_state *state) |
23 | { | |
24 | return NULL; | |
25 | } | |
26 | ||
7c7900f8 JP |
27 | bool unwind_next_frame(struct unwind_state *state) |
28 | { | |
29 | struct stack_info *info = &state->stack_info; | |
30 | ||
31 | if (unwind_done(state)) | |
32 | return false; | |
33 | ||
34 | do { | |
55f856e6 JP |
35 | for (state->sp++; state->sp < info->end; state->sp++) { |
36 | unsigned long addr = READ_ONCE_NOCHECK(*state->sp); | |
c2d75e03 | 37 | |
c2d75e03 | 38 | if (__kernel_text_address(addr)) |
7c7900f8 | 39 | return true; |
55f856e6 | 40 | } |
7c7900f8 | 41 | |
e335bb51 | 42 | state->sp = PTR_ALIGN(info->next_sp, sizeof(long)); |
7c7900f8 JP |
43 | |
44 | } while (!get_stack_info(state->sp, state->task, info, | |
45 | &state->stack_mask)); | |
46 | ||
47 | return false; | |
48 | } | |
49 | EXPORT_SYMBOL_GPL(unwind_next_frame); | |
50 | ||
51 | void __unwind_start(struct unwind_state *state, struct task_struct *task, | |
52 | struct pt_regs *regs, unsigned long *first_frame) | |
53 | { | |
54 | memset(state, 0, sizeof(*state)); | |
55 | ||
56 | state->task = task; | |
e335bb51 | 57 | state->sp = PTR_ALIGN(first_frame, sizeof(long)); |
7c7900f8 JP |
58 | |
59 | get_stack_info(first_frame, state->task, &state->stack_info, | |
60 | &state->stack_mask); | |
61 | ||
7fbe6ac0 JP |
62 | /* |
63 | * The caller can provide the address of the first frame directly | |
64 | * (first_frame) or indirectly (regs->sp) to indicate which stack frame | |
65 | * to start unwinding at. Skip ahead until we reach it. | |
66 | */ | |
67 | if (!unwind_done(state) && | |
68 | (!on_stack(&state->stack_info, first_frame, sizeof(long)) || | |
69 | !__kernel_text_address(*first_frame))) | |
7c7900f8 JP |
70 | unwind_next_frame(state); |
71 | } | |
72 | EXPORT_SYMBOL_GPL(__unwind_start); |