1*5f757f3fSDimitry Andric //===------------------ sanitizer_unwind_fuchsia.cpp
2*5f757f3fSDimitry Andric //---------------------------===//
3*5f757f3fSDimitry Andric //
4*5f757f3fSDimitry Andric // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
5*5f757f3fSDimitry Andric // See https://llvm.org/LICENSE.txt for license information.
6*5f757f3fSDimitry Andric // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7*5f757f3fSDimitry Andric //
8*5f757f3fSDimitry Andric //===----------------------------------------------------------------------===//
9*5f757f3fSDimitry Andric //
10*5f757f3fSDimitry Andric /// Sanitizer unwind Fuchsia specific functions.
11*5f757f3fSDimitry Andric //
12*5f757f3fSDimitry Andric //===----------------------------------------------------------------------===//
13*5f757f3fSDimitry Andric
14*5f757f3fSDimitry Andric #include "sanitizer_platform.h"
15*5f757f3fSDimitry Andric #if SANITIZER_FUCHSIA
16*5f757f3fSDimitry Andric
17*5f757f3fSDimitry Andric # include <limits.h>
18*5f757f3fSDimitry Andric # include <unwind.h>
19*5f757f3fSDimitry Andric
20*5f757f3fSDimitry Andric # include "sanitizer_common.h"
21*5f757f3fSDimitry Andric # include "sanitizer_stacktrace.h"
22*5f757f3fSDimitry Andric
23*5f757f3fSDimitry Andric namespace __sanitizer {
24*5f757f3fSDimitry Andric
25*5f757f3fSDimitry Andric # if SANITIZER_CAN_SLOW_UNWIND
26*5f757f3fSDimitry Andric struct UnwindTraceArg {
27*5f757f3fSDimitry Andric BufferedStackTrace *stack;
28*5f757f3fSDimitry Andric u32 max_depth;
29*5f757f3fSDimitry Andric };
30*5f757f3fSDimitry Andric
Unwind_Trace(struct _Unwind_Context * ctx,void * param)31*5f757f3fSDimitry Andric _Unwind_Reason_Code Unwind_Trace(struct _Unwind_Context *ctx, void *param) {
32*5f757f3fSDimitry Andric UnwindTraceArg *arg = static_cast<UnwindTraceArg *>(param);
33*5f757f3fSDimitry Andric CHECK_LT(arg->stack->size, arg->max_depth);
34*5f757f3fSDimitry Andric uptr pc = _Unwind_GetIP(ctx);
35*5f757f3fSDimitry Andric if (pc < GetPageSizeCached())
36*5f757f3fSDimitry Andric return _URC_NORMAL_STOP;
37*5f757f3fSDimitry Andric arg->stack->trace_buffer[arg->stack->size++] = pc;
38*5f757f3fSDimitry Andric return (arg->stack->size == arg->max_depth ? _URC_NORMAL_STOP
39*5f757f3fSDimitry Andric : _URC_NO_REASON);
40*5f757f3fSDimitry Andric }
41*5f757f3fSDimitry Andric
UnwindSlow(uptr pc,u32 max_depth)42*5f757f3fSDimitry Andric void BufferedStackTrace::UnwindSlow(uptr pc, u32 max_depth) {
43*5f757f3fSDimitry Andric CHECK_GE(max_depth, 2);
44*5f757f3fSDimitry Andric size = 0;
45*5f757f3fSDimitry Andric UnwindTraceArg arg = {this, Min(max_depth + 1, kStackTraceMax)};
46*5f757f3fSDimitry Andric _Unwind_Backtrace(Unwind_Trace, &arg);
47*5f757f3fSDimitry Andric CHECK_GT(size, 0);
48*5f757f3fSDimitry Andric // We need to pop a few frames so that pc is on top.
49*5f757f3fSDimitry Andric uptr to_pop = LocatePcInTrace(pc);
50*5f757f3fSDimitry Andric // trace_buffer[0] belongs to the current function so we always pop it,
51*5f757f3fSDimitry Andric // unless there is only 1 frame in the stack trace (1 frame is always better
52*5f757f3fSDimitry Andric // than 0!).
53*5f757f3fSDimitry Andric PopStackFrames(Min(to_pop, static_cast<uptr>(1)));
54*5f757f3fSDimitry Andric trace_buffer[0] = pc;
55*5f757f3fSDimitry Andric }
56*5f757f3fSDimitry Andric
UnwindSlow(uptr pc,void * context,u32 max_depth)57*5f757f3fSDimitry Andric void BufferedStackTrace::UnwindSlow(uptr pc, void *context, u32 max_depth) {
58*5f757f3fSDimitry Andric CHECK(context);
59*5f757f3fSDimitry Andric CHECK_GE(max_depth, 2);
60*5f757f3fSDimitry Andric UNREACHABLE("signal context doesn't exist");
61*5f757f3fSDimitry Andric }
62*5f757f3fSDimitry Andric # endif // SANITIZER_CAN_SLOW_UNWIND
63*5f757f3fSDimitry Andric
64*5f757f3fSDimitry Andric } // namespace __sanitizer
65*5f757f3fSDimitry Andric
66*5f757f3fSDimitry Andric #endif // SANITIZER_FUCHSIA
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