1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Stack trace management functions 4 * 5 * Copyright IBM Corp. 2006 6 * Author(s): Heiko Carstens <heiko.carstens@de.ibm.com> 7 */ 8 9 #include <linux/stacktrace.h> 10 #include <asm/stacktrace.h> 11 #include <asm/unwind.h> 12 #include <asm/kprobes.h> 13 14 void arch_stack_walk(stack_trace_consume_fn consume_entry, void *cookie, 15 struct task_struct *task, struct pt_regs *regs) 16 { 17 struct unwind_state state; 18 unsigned long addr; 19 20 unwind_for_each_frame(&state, task, regs, 0) { 21 addr = unwind_get_return_address(&state); 22 if (!addr || !consume_entry(cookie, addr)) 23 break; 24 } 25 } 26 27 int arch_stack_walk_reliable(stack_trace_consume_fn consume_entry, 28 void *cookie, struct task_struct *task) 29 { 30 struct unwind_state state; 31 unsigned long addr; 32 33 unwind_for_each_frame(&state, task, NULL, 0) { 34 if (state.stack_info.type != STACK_TYPE_TASK) 35 return -EINVAL; 36 37 if (state.regs) 38 return -EINVAL; 39 40 addr = unwind_get_return_address(&state); 41 if (!addr) 42 return -EINVAL; 43 44 #ifdef CONFIG_KPROBES 45 /* 46 * Mark stacktraces with kretprobed functions on them 47 * as unreliable. 48 */ 49 if (state.ip == (unsigned long)__kretprobe_trampoline) 50 return -EINVAL; 51 #endif 52 53 if (!consume_entry(cookie, addr)) 54 return -EINVAL; 55 } 56 57 /* Check for stack corruption */ 58 if (unwind_error(&state)) 59 return -EINVAL; 60 return 0; 61 } 62