![Ingo Molnar](/assets/img/avatar_default.png)
But first update the usage sites with the new header dependency. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
190 lines
4.5 KiB
C
190 lines
4.5 KiB
C
#include <linux/export.h>
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#include <linux/sched.h>
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#include <linux/sched/debug.h>
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#include <linux/sched/task_stack.h>
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#include <linux/stacktrace.h>
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#include <asm/stacktrace.h>
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#if defined(CONFIG_FRAME_POINTER)
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#ifdef CONFIG_KALLSYMS
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#include <linux/kallsyms.h>
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#include <linux/module.h>
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static unsigned long tbi_boing_addr;
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static unsigned long tbi_boing_size;
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static void tbi_boing_init(void)
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{
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/* We need to know where TBIBoingVec is and it's size */
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unsigned long size;
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unsigned long offset;
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char modname[MODULE_NAME_LEN];
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char name[KSYM_NAME_LEN];
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tbi_boing_addr = kallsyms_lookup_name("___TBIBoingVec");
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if (!tbi_boing_addr)
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tbi_boing_addr = 1;
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else if (!lookup_symbol_attrs(tbi_boing_addr, &size,
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&offset, modname, name))
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tbi_boing_size = size;
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}
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#endif
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#define ALIGN_DOWN(addr, size) ((addr)&(~((size)-1)))
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/*
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* Unwind the current stack frame and store the new register values in the
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* structure passed as argument. Unwinding is equivalent to a function return,
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* hence the new PC value rather than LR should be used for backtrace.
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*/
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int notrace unwind_frame(struct stackframe *frame)
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{
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struct metag_frame *fp = (struct metag_frame *)frame->fp;
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unsigned long lr;
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unsigned long fpnew;
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if (frame->fp & 0x7)
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return -EINVAL;
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fpnew = fp->fp;
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lr = fp->lr - 4;
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#ifdef CONFIG_KALLSYMS
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/* If we've reached TBIBoingVec then we're at an interrupt
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* entry point or a syscall entry point. The frame pointer
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* points to a pt_regs which can be used to continue tracing on
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* the other side of the boing.
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*/
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if (!tbi_boing_addr)
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tbi_boing_init();
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if (tbi_boing_size && lr >= tbi_boing_addr &&
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lr < tbi_boing_addr + tbi_boing_size) {
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struct pt_regs *regs = (struct pt_regs *)fpnew;
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if (user_mode(regs))
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return -EINVAL;
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fpnew = regs->ctx.AX[1].U0;
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lr = regs->ctx.DX[4].U1;
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}
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#endif
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/* stack grows up, so frame pointers must decrease */
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if (fpnew < (ALIGN_DOWN((unsigned long)fp, THREAD_SIZE) +
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sizeof(struct thread_info)) || fpnew >= (unsigned long)fp)
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return -EINVAL;
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/* restore the registers from the stack frame */
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frame->fp = fpnew;
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frame->pc = lr;
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return 0;
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}
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#else
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int notrace unwind_frame(struct stackframe *frame)
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{
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struct metag_frame *sp = (struct metag_frame *)frame->sp;
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if (frame->sp & 0x7)
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return -EINVAL;
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while (!kstack_end(sp)) {
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unsigned long addr = sp->lr - 4;
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sp--;
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if (__kernel_text_address(addr)) {
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frame->sp = (unsigned long)sp;
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frame->pc = addr;
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return 0;
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}
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}
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return -EINVAL;
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}
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#endif
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void notrace walk_stackframe(struct stackframe *frame,
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int (*fn)(struct stackframe *, void *), void *data)
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{
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while (1) {
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int ret;
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if (fn(frame, data))
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break;
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ret = unwind_frame(frame);
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if (ret < 0)
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break;
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}
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}
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EXPORT_SYMBOL(walk_stackframe);
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#ifdef CONFIG_STACKTRACE
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struct stack_trace_data {
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struct stack_trace *trace;
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unsigned int no_sched_functions;
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unsigned int skip;
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};
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static int save_trace(struct stackframe *frame, void *d)
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{
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struct stack_trace_data *data = d;
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struct stack_trace *trace = data->trace;
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unsigned long addr = frame->pc;
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if (data->no_sched_functions && in_sched_functions(addr))
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return 0;
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if (data->skip) {
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data->skip--;
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return 0;
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}
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trace->entries[trace->nr_entries++] = addr;
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return trace->nr_entries >= trace->max_entries;
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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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struct stack_trace_data data;
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struct stackframe frame;
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data.trace = trace;
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data.skip = trace->skip;
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if (tsk != current) {
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#ifdef CONFIG_SMP
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/*
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* What guarantees do we have here that 'tsk' is not
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* running on another CPU? For now, ignore it as we
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* can't guarantee we won't explode.
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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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return;
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#else
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data.no_sched_functions = 1;
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frame.fp = thread_saved_fp(tsk);
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frame.sp = thread_saved_sp(tsk);
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frame.lr = 0; /* recovered from the stack */
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frame.pc = thread_saved_pc(tsk);
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#endif
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} else {
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register unsigned long current_sp asm ("A0StP");
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data.no_sched_functions = 0;
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frame.fp = (unsigned long)__builtin_frame_address(0);
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frame.sp = current_sp;
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frame.lr = (unsigned long)__builtin_return_address(0);
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frame.pc = (unsigned long)save_stack_trace_tsk;
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}
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walk_stackframe(&frame, save_trace, &data);
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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(struct stack_trace *trace)
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{
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save_stack_trace_tsk(current, trace);
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}
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EXPORT_SYMBOL_GPL(save_stack_trace);
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#endif
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