79 lines · cpp
1//===-- sanitizer_stacktrace_sparc.cpp ------------------------------------===//2//3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.4// See https://llvm.org/LICENSE.txt for license information.5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception6//7//===----------------------------------------------------------------------===//8//9// This file is shared between AddressSanitizer and ThreadSanitizer10// run-time libraries.11//12// Implementation of fast stack unwinding for Sparc.13//===----------------------------------------------------------------------===//14 15#if defined(__sparc__)16 17#if defined(__arch64__) || defined(__sparcv9)18#define STACK_BIAS 204719#else20#define STACK_BIAS 021#endif22 23#include "sanitizer_common.h"24#include "sanitizer_stacktrace.h"25 26namespace __sanitizer {27 28void BufferedStackTrace::UnwindFast(uptr pc, uptr bp, uptr stack_top,29 uptr stack_bottom, u32 max_depth) {30 // TODO(yln): add arg sanity check for stack_top/stack_bottom31 CHECK_GE(max_depth, 2);32 const uptr kPageSize = GetPageSizeCached();33 trace_buffer[0] = pc;34 size = 1;35 if (stack_top < 4096) return; // Sanity check for stack top.36 // Flush register windows to memory37#if defined(__sparc_v9__) || defined(__sparcv9__) || defined(__sparcv9)38 asm volatile("flushw" ::: "memory");39#else40 asm volatile("ta 3" ::: "memory");41#endif42 // On the SPARC, the return address is not in the frame, it is in a43 // register. There is no way to access it off of the current frame44 // pointer, but it can be accessed off the previous frame pointer by45 // reading the value from the register window save area.46 uptr prev_bp = GET_CURRENT_FRAME();47 uptr next_bp = prev_bp;48 unsigned int i = 0;49 while (next_bp != bp && IsAligned(next_bp, sizeof(uhwptr)) && i++ < 8) {50 prev_bp = next_bp;51 next_bp = (uptr)((uhwptr *)next_bp)[14] + STACK_BIAS;52 }53 if (next_bp == bp)54 bp = prev_bp;55 // Lowest possible address that makes sense as the next frame pointer.56 // Goes up as we walk the stack.57 uptr bottom = stack_bottom;58 // Avoid infinite loop when frame == frame[0] by using frame > prev_frame.59 while (IsValidFrame(bp, stack_top, bottom) && IsAligned(bp, sizeof(uhwptr)) &&60 size < max_depth) {61 // %o7 contains the address of the call instruction and not the62 // return address, so we need to compensate.63 uhwptr pc1 = GetNextInstructionPc(((uhwptr *)bp)[15]);64 // Let's assume that any pointer in the 0th page is invalid and65 // stop unwinding here. If we're adding support for a platform66 // where this isn't true, we need to reconsider this check.67 if (pc1 < kPageSize)68 break;69 if (pc1 != pc)70 trace_buffer[size++] = pc1;71 bottom = bp;72 bp = (uptr)((uhwptr *)bp)[14] + STACK_BIAS;73 }74}75 76} // namespace __sanitizer77 78#endif // !defined(__sparc__)79