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Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149// SPDX-License-Identifier: GPL-2.0/* * Stack trace management functions * * Copyright IBM Corp. 2006 */
#include <linux/perf_event.h>#include <linux/stacktrace.h>#include <linux/uaccess.h>#include <asm/asm-offsets.h>#include <asm/stacktrace.h>#include <asm/unwind.h>#include <asm/kprobes.h>#include <asm/ptrace.h>
void arch_stack_walk(stack_trace_consume_fn consume_entry, void *cookie, struct task_struct *task, struct pt_regs *regs){ struct unwind_state state; unsigned long addr;
unwind_for_each_frame(&state, task, regs, 0) { 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){ struct unwind_state state; unsigned long addr;
unwind_for_each_frame(&state, task, NULL, 0) { if (state.stack_info.type != STACK_TYPE_TASK) return -EINVAL;
if (state.regs) return -EINVAL;
addr = unwind_get_return_address(&state); if (!addr) return -EINVAL;
#ifdef CONFIG_RETHOOK /* * Mark stacktraces with krethook functions on them * as unreliable. */ if (state.ip == (unsigned long)arch_rethook_trampoline) return -EINVAL;#endif
if (!consume_entry(cookie, addr)) return -EINVAL; }
/* Check for stack corruption */ if (unwind_error(&state)) return -EINVAL; return 0;}
static inline bool store_ip(stack_trace_consume_fn consume_entry, void *cookie, struct perf_callchain_entry_ctx *entry, bool perf, unsigned long ip){#ifdef CONFIG_PERF_EVENTS if (perf) { if (perf_callchain_store(entry, ip)) return false; return true; }#endif return consume_entry(cookie, ip);}
static inline bool ip_invalid(unsigned long ip){ /* * Perform some basic checks if an instruction address taken * from unreliable source is invalid. */ if (ip & 1) return true; if (ip < mmap_min_addr) return true; if (ip >= current->mm->context.asce_limit) return true; return false;}
static inline bool ip_within_vdso(unsigned long ip){ return in_range(ip, current->mm->context.vdso_base, vdso_text_size());}
void arch_stack_walk_user_common(stack_trace_consume_fn consume_entry, void *cookie, struct perf_callchain_entry_ctx *entry, const struct pt_regs *regs, bool perf){ struct stack_frame_vdso_wrapper __user *sf_vdso; struct stack_frame_user __user *sf; unsigned long ip, sp;
if (!current->mm) return; ip = instruction_pointer(regs); if (!store_ip(consume_entry, cookie, entry, perf, ip)) return; sf = (void __user *)user_stack_pointer(regs); pagefault_disable(); while (1) { if (__get_user(sp, &sf->back_chain)) break; /* * VDSO entry code has a non-standard stack frame layout. * See VDSO user wrapper code for details. */ if (!sp && ip_within_vdso(ip)) { sf_vdso = (void __user *)sf; if (__get_user(ip, &sf_vdso->return_address)) break; sp = (unsigned long)sf + STACK_FRAME_VDSO_OVERHEAD; sf = (void __user *)sp; if (__get_user(sp, &sf->back_chain)) break; } else { sf = (void __user *)sp; if (__get_user(ip, &sf->gprs[8])) break; } /* Validate SP and RA (ABI requires SP to be 8 byte aligned). */ if (sp & 0x7 || ip_invalid(ip)) break; if (!store_ip(consume_entry, cookie, entry, perf, ip)) break; } pagefault_enable();}
void arch_stack_walk_user(stack_trace_consume_fn consume_entry, void *cookie, const struct pt_regs *regs){ arch_stack_walk_user_common(consume_entry, cookie, NULL, regs, false);}