acc6be5405
This will help kmemcheck (and possibly other debugging tools) since we can now simply pass regs->bp to the stack tracer instead of specifying the number of stack frames to skip, which is unreliable if gcc decides to inline functions, etc. Note that this makes the API incomplete for other architectures, but I expect that those can be updated lazily, e.g. when they need it. Cc: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Vegard Nossum <vegard.nossum@gmail.com>
156 lines
3.6 KiB
C
156 lines
3.6 KiB
C
/*
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* Stack trace management functions
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*
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* Copyright (C) 2006-2009 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
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*/
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#include <linux/sched.h>
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#include <linux/stacktrace.h>
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#include <linux/module.h>
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#include <linux/uaccess.h>
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#include <asm/stacktrace.h>
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static void save_stack_warning(void *data, char *msg)
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{
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}
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static void
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save_stack_warning_symbol(void *data, char *msg, unsigned long symbol)
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{
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}
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static int save_stack_stack(void *data, char *name)
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{
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return 0;
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}
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static void save_stack_address(void *data, unsigned long addr, int reliable)
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{
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struct stack_trace *trace = data;
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if (!reliable)
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return;
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if (trace->skip > 0) {
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trace->skip--;
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return;
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}
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if (trace->nr_entries < trace->max_entries)
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trace->entries[trace->nr_entries++] = addr;
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}
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static void
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save_stack_address_nosched(void *data, unsigned long addr, int reliable)
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{
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struct stack_trace *trace = (struct stack_trace *)data;
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if (!reliable)
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return;
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if (in_sched_functions(addr))
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return;
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if (trace->skip > 0) {
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trace->skip--;
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return;
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}
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if (trace->nr_entries < trace->max_entries)
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trace->entries[trace->nr_entries++] = addr;
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}
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static const struct stacktrace_ops save_stack_ops = {
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.warning = save_stack_warning,
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.warning_symbol = save_stack_warning_symbol,
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.stack = save_stack_stack,
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.address = save_stack_address,
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};
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static const struct stacktrace_ops save_stack_ops_nosched = {
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.warning = save_stack_warning,
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.warning_symbol = save_stack_warning_symbol,
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.stack = save_stack_stack,
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.address = save_stack_address_nosched,
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};
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/*
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* Save stack-backtrace addresses into a stack_trace buffer.
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*/
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void save_stack_trace(struct stack_trace *trace)
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{
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dump_trace(current, NULL, NULL, 0, &save_stack_ops, trace);
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if (trace->nr_entries < trace->max_entries)
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trace->entries[trace->nr_entries++] = ULONG_MAX;
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}
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EXPORT_SYMBOL_GPL(save_stack_trace);
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void save_stack_trace_bp(struct stack_trace *trace, unsigned long bp)
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{
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dump_trace(current, NULL, NULL, bp, &save_stack_ops, trace);
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if (trace->nr_entries < trace->max_entries)
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trace->entries[trace->nr_entries++] = ULONG_MAX;
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}
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void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
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{
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dump_trace(tsk, NULL, NULL, 0, &save_stack_ops_nosched, trace);
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if (trace->nr_entries < trace->max_entries)
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trace->entries[trace->nr_entries++] = ULONG_MAX;
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}
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EXPORT_SYMBOL_GPL(save_stack_trace_tsk);
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/* Userspace stacktrace - based on kernel/trace/trace_sysprof.c */
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struct stack_frame {
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const void __user *next_fp;
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unsigned long ret_addr;
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};
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static int copy_stack_frame(const void __user *fp, struct stack_frame *frame)
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{
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int ret;
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if (!access_ok(VERIFY_READ, fp, sizeof(*frame)))
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return 0;
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ret = 1;
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pagefault_disable();
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if (__copy_from_user_inatomic(frame, fp, sizeof(*frame)))
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ret = 0;
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pagefault_enable();
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return ret;
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}
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static inline void __save_stack_trace_user(struct stack_trace *trace)
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{
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const struct pt_regs *regs = task_pt_regs(current);
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const void __user *fp = (const void __user *)regs->bp;
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if (trace->nr_entries < trace->max_entries)
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trace->entries[trace->nr_entries++] = regs->ip;
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while (trace->nr_entries < trace->max_entries) {
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struct stack_frame frame;
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frame.next_fp = NULL;
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frame.ret_addr = 0;
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if (!copy_stack_frame(fp, &frame))
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break;
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if ((unsigned long)fp < regs->sp)
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break;
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if (frame.ret_addr) {
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trace->entries[trace->nr_entries++] =
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frame.ret_addr;
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}
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if (fp == frame.next_fp)
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break;
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fp = frame.next_fp;
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}
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}
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void save_stack_trace_user(struct stack_trace *trace)
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{
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/*
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* Trace user stack if we are not a kernel thread
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*/
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if (current->mm) {
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__save_stack_trace_user(trace);
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}
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if (trace->nr_entries < trace->max_entries)
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trace->entries[trace->nr_entries++] = ULONG_MAX;
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}
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