1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | #include <linux/sched.h> |
3 | #include <linux/sched/debug.h> |
4 | #include <linux/stacktrace.h> |
5 | #include <linux/thread_info.h> |
6 | #include <linux/ftrace.h> |
7 | #include <linux/export.h> |
8 | #include <asm/ptrace.h> |
9 | #include <asm/stacktrace.h> |
10 | |
11 | #include "kstack.h" |
12 | |
13 | static void __save_stack_trace(struct thread_info *tp, |
14 | struct stack_trace *trace, |
15 | bool skip_sched) |
16 | { |
17 | unsigned long ksp, fp; |
18 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
19 | struct task_struct *t; |
20 | int graph = 0; |
21 | #endif |
22 | |
23 | if (tp == current_thread_info()) { |
24 | stack_trace_flush(); |
25 | __asm__ __volatile__("mov %%fp, %0" : "=r" (ksp)); |
26 | } else { |
27 | ksp = tp->ksp; |
28 | } |
29 | |
30 | fp = ksp + STACK_BIAS; |
31 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
32 | t = tp->task; |
33 | #endif |
34 | do { |
35 | struct sparc_stackf *sf; |
36 | struct pt_regs *regs; |
37 | unsigned long pc; |
38 | |
39 | if (!kstack_valid(tp, sp: fp)) |
40 | break; |
41 | |
42 | sf = (struct sparc_stackf *) fp; |
43 | regs = (struct pt_regs *) (sf + 1); |
44 | |
45 | if (kstack_is_trap_frame(tp, regs)) { |
46 | if (!(regs->tstate & TSTATE_PRIV)) |
47 | break; |
48 | pc = regs->tpc; |
49 | fp = regs->u_regs[UREG_I6] + STACK_BIAS; |
50 | } else { |
51 | pc = sf->callers_pc; |
52 | fp = (unsigned long)sf->fp + STACK_BIAS; |
53 | } |
54 | |
55 | if (trace->skip > 0) |
56 | trace->skip--; |
57 | else if (!skip_sched || !in_sched_functions(addr: pc)) { |
58 | trace->entries[trace->nr_entries++] = pc; |
59 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
60 | if ((pc + 8UL) == (unsigned long) &return_to_handler) { |
61 | struct ftrace_ret_stack *ret_stack; |
62 | ret_stack = ftrace_graph_get_ret_stack(task: t, |
63 | idx: graph); |
64 | if (ret_stack) { |
65 | pc = ret_stack->ret; |
66 | if (trace->nr_entries < |
67 | trace->max_entries) |
68 | trace->entries[trace->nr_entries++] = pc; |
69 | graph++; |
70 | } |
71 | } |
72 | #endif |
73 | } |
74 | } while (trace->nr_entries < trace->max_entries); |
75 | } |
76 | |
77 | void save_stack_trace(struct stack_trace *trace) |
78 | { |
79 | __save_stack_trace(current_thread_info(), trace, skip_sched: false); |
80 | } |
81 | EXPORT_SYMBOL_GPL(save_stack_trace); |
82 | |
83 | void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace) |
84 | { |
85 | struct thread_info *tp = task_thread_info(tsk); |
86 | |
87 | __save_stack_trace(tp, trace, skip_sched: true); |
88 | } |
89 | EXPORT_SYMBOL_GPL(save_stack_trace_tsk); |
90 | |