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-exception 6// 7//===----------------------------------------------------------------------===// 8// 9// This file is shared between AddressSanitizer and ThreadSanitizer 10// 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 2047 19#else 20#define STACK_BIAS 0 21#endif 22 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_bottom 31 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 memory 37#if defined(__sparc_v9__) || defined(__sparcv9__) || defined(__sparcv9) 38 asm volatile("flushw" ::: "memory"); 39#else 40 asm volatile("ta 3" ::: "memory"); 41#endif 42 // On the SPARC, the return address is not in the frame, it is in a 43 // register. There is no way to access it off of the current frame 44 // pointer, but it can be accessed off the previous frame pointer by 45 // 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 uhwptr pc1 = ((uhwptr *)bp)[15]; 62 // Let's assume that any pointer in the 0th page is invalid and 63 // stop unwinding here. If we're adding support for a platform 64 // where this isn't true, we need to reconsider this check. 65 if (pc1 < kPageSize) 66 break; 67 if (pc1 != pc) { 68 // %o7 contains the address of the call instruction and not the 69 // return address, so we need to compensate. 70 trace_buffer[size++] = GetNextInstructionPc((uptr)pc1); 71 } 72 bottom = bp; 73 bp = (uptr)((uhwptr *)bp)[14] + STACK_BIAS; 74 } 75} 76 77} // namespace __sanitizer 78 79#endif // !defined(__sparc__) 80