[compiler-rt] r355965 - SanitizerCommon: fixes for unwinding & backtrace on SPARC
Vitaly Buka via llvm-commits
llvm-commits at lists.llvm.org
Tue Mar 12 13:31:54 PDT 2019
Author: vitalybuka
Date: Tue Mar 12 13:31:53 2019
New Revision: 355965
URL: http://llvm.org/viewvc/llvm-project?rev=355965&view=rev
Log:
SanitizerCommon: fixes for unwinding & backtrace on SPARC
Summary:
This patch contains various fixes for the unwinding and backtrace machinery on the SPARC, which doesn't work correctly in various cases. It was tested with GCC on SPARC/Solaris and SPARC/Linux.
Patch by Eric Botcazou.
Reviewers: #sanitizers, vitalybuka
Reviewed By: #sanitizers, vitalybuka
Subscribers: jrtc27, delcypher, vitalybuka, ro, jyknight, kubamracek, fedor.sergeev, jdoerfert, llvm-commits, #sanitizers
Tags: #sanitizers, #llvm
Differential Revision: https://reviews.llvm.org/D58431
Modified:
compiler-rt/trunk/lib/sanitizer_common/sanitizer_linux.cc
compiler-rt/trunk/lib/sanitizer_common/sanitizer_stacktrace.cc
compiler-rt/trunk/lib/sanitizer_common/sanitizer_stacktrace.h
compiler-rt/trunk/lib/sanitizer_common/sanitizer_stacktrace_sparc.cc
compiler-rt/trunk/lib/sanitizer_common/sanitizer_unwind_linux_libcdep.cc
Modified: compiler-rt/trunk/lib/sanitizer_common/sanitizer_linux.cc
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/sanitizer_common/sanitizer_linux.cc?rev=355965&r1=355964&r2=355965&view=diff
==============================================================================
--- compiler-rt/trunk/lib/sanitizer_common/sanitizer_linux.cc (original)
+++ compiler-rt/trunk/lib/sanitizer_common/sanitizer_linux.cc Tue Mar 12 13:31:53 2019
@@ -1821,10 +1821,20 @@ SignalContext::WriteFlag SignalContext::
u64 esr;
if (!Aarch64GetESR(ucontext, &esr)) return UNKNOWN;
return esr & ESR_ELx_WNR ? WRITE : READ;
-#elif SANITIZER_SOLARIS && defined(__sparc__)
+#elif defined(__sparc__)
// Decode the instruction to determine the access type.
// From OpenSolaris $SRC/uts/sun4/os/trap.c (get_accesstype).
+#if SANITIZER_SOLARIS
uptr pc = ucontext->uc_mcontext.gregs[REG_PC];
+#else
+ // Historical BSDism here.
+ struct sigcontext *scontext = (struct sigcontext *)context;
+#if defined(__arch64__)
+ uptr pc = scontext->sigc_regs.tpc;
+#else
+ uptr pc = scontext->si_regs.pc;
+#endif
+#endif
u32 instr = *(u32 *)pc;
return (instr >> 21) & 1 ? WRITE: READ;
#else
@@ -1915,28 +1925,27 @@ static void GetPcSpBp(void *context, upt
// pointer, but GCC always uses r31 when we need a frame pointer.
*bp = ucontext->uc_mcontext.regs->gpr[PT_R31];
#elif defined(__sparc__)
- ucontext_t *ucontext = (ucontext_t*)context;
- uptr *stk_ptr;
-# if defined(__sparcv9) || defined (__arch64__)
-# ifndef MC_PC
-# define MC_PC REG_PC
-# endif
-# ifndef MC_O6
-# define MC_O6 REG_O6
+#if defined(__arch64__) || defined(__sparcv9)
+#define STACK_BIAS 2047
+#else
+#define STACK_BIAS 0
# endif
# if SANITIZER_SOLARIS
-# define mc_gregs gregs
-# endif
- *pc = ucontext->uc_mcontext.mc_gregs[MC_PC];
- *sp = ucontext->uc_mcontext.mc_gregs[MC_O6];
- stk_ptr = (uptr *) (*sp + 2047);
- *bp = stk_ptr[15];
-# else
+ ucontext_t *ucontext = (ucontext_t *)context;
*pc = ucontext->uc_mcontext.gregs[REG_PC];
- *sp = ucontext->uc_mcontext.gregs[REG_O6];
- stk_ptr = (uptr *) *sp;
- *bp = stk_ptr[15];
+ *sp = ucontext->uc_mcontext.gregs[REG_O6] + STACK_BIAS;
+#else
+ // Historical BSDism here.
+ struct sigcontext *scontext = (struct sigcontext *)context;
+#if defined(__arch64__)
+ *pc = scontext->sigc_regs.tpc;
+ *sp = scontext->sigc_regs.u_regs[14] + STACK_BIAS;
+#else
+ *pc = scontext->si_regs.pc;
+ *sp = scontext->si_regs.u_regs[14];
+#endif
# endif
+ *bp = (uptr)((uhwptr *)*sp)[14] + STACK_BIAS;
#elif defined(__mips__)
ucontext_t *ucontext = (ucontext_t*)context;
*pc = ucontext->uc_mcontext.pc;
Modified: compiler-rt/trunk/lib/sanitizer_common/sanitizer_stacktrace.cc
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/sanitizer_common/sanitizer_stacktrace.cc?rev=355965&r1=355964&r2=355965&view=diff
==============================================================================
--- compiler-rt/trunk/lib/sanitizer_common/sanitizer_stacktrace.cc (original)
+++ compiler-rt/trunk/lib/sanitizer_common/sanitizer_stacktrace.cc Tue Mar 12 13:31:53 2019
@@ -17,10 +17,9 @@
namespace __sanitizer {
uptr StackTrace::GetNextInstructionPc(uptr pc) {
-#if defined(__mips__)
+#if defined(__sparc__) || defined(__mips__)
return pc + 8;
-#elif defined(__powerpc__) || defined(__sparc__) || defined(__arm__) || \
- defined(__aarch64__)
+#elif defined(__powerpc__) || defined(__arm__) || defined(__aarch64__)
return pc + 4;
#else
return pc + 1;
Modified: compiler-rt/trunk/lib/sanitizer_common/sanitizer_stacktrace.h
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/sanitizer_common/sanitizer_stacktrace.h?rev=355965&r1=355964&r2=355965&view=diff
==============================================================================
--- compiler-rt/trunk/lib/sanitizer_common/sanitizer_stacktrace.h (original)
+++ compiler-rt/trunk/lib/sanitizer_common/sanitizer_stacktrace.h Tue Mar 12 13:31:53 2019
@@ -20,7 +20,7 @@ struct BufferedStackTrace;
static const u32 kStackTraceMax = 256;
-#if defined(__sparc__) || (SANITIZER_LINUX && defined(__mips__))
+#if SANITIZER_LINUX && defined(__mips__)
# define SANITIZER_CAN_FAST_UNWIND 0
#elif SANITIZER_WINDOWS
# define SANITIZER_CAN_FAST_UNWIND 0
Modified: compiler-rt/trunk/lib/sanitizer_common/sanitizer_stacktrace_sparc.cc
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/sanitizer_common/sanitizer_stacktrace_sparc.cc?rev=355965&r1=355964&r2=355965&view=diff
==============================================================================
--- compiler-rt/trunk/lib/sanitizer_common/sanitizer_stacktrace_sparc.cc (original)
+++ compiler-rt/trunk/lib/sanitizer_common/sanitizer_stacktrace_sparc.cc Tue Mar 12 13:31:53 2019
@@ -12,9 +12,13 @@
// Implemention of fast stack unwinding for Sparc.
//===----------------------------------------------------------------------===//
-// This file is ported to Sparc v8, but it should be easy to port to
-// Sparc v9.
-#if defined(__sparcv8__) || defined(__sparcv8) || defined(__sparc_v8__)
+#if defined(__sparc__)
+
+#if defined(__arch64__) || defined(__sparcv9)
+#define STACK_BIAS 2047
+#else
+#define STACK_BIAS 0
+#endif
#include "sanitizer_common.h"
#include "sanitizer_stacktrace.h"
@@ -26,34 +30,56 @@ void BufferedStackTrace::UnwindFast(uptr
// TODO(yln): add arg sanity check for stack_top/stack_bottom
CHECK_GE(max_depth, 2);
const uptr kPageSize = GetPageSizeCached();
+#if defined(__GNUC__)
+ // __builtin_return_address returns the address of the call instruction
+ // on the SPARC and not the return address, so we need to compensate.
+ trace_buffer[0] = GetNextInstructionPc(pc);
+#else
trace_buffer[0] = pc;
+#endif
size = 1;
if (stack_top < 4096) return; // Sanity check for stack top.
// Flush register windows to memory
+#if defined(__sparc_v9__) || defined(__sparcv9__) || defined(__sparcv9)
+ asm volatile("flushw" ::: "memory");
+#else
asm volatile("ta 3" ::: "memory");
- uhwptr *frame = (uhwptr*)bp;
+#endif
+ // On the SPARC, the return address is not in the frame, it is in a
+ // register. There is no way to access it off of the current frame
+ // pointer, but it can be accessed off the previous frame pointer by
+ // reading the value from the register window save area.
+ uptr prev_bp = GET_CURRENT_FRAME();
+ uptr next_bp = prev_bp;
+ unsigned int i = 0;
+ while (next_bp != bp && IsAligned(next_bp, sizeof(uhwptr)) && i++ < 8) {
+ prev_bp = next_bp;
+ next_bp = (uptr)((uhwptr *)next_bp)[14] + STACK_BIAS;
+ }
+ if (next_bp == bp)
+ bp = prev_bp;
// Lowest possible address that makes sense as the next frame pointer.
// Goes up as we walk the stack.
uptr bottom = stack_bottom;
// Avoid infinite loop when frame == frame[0] by using frame > prev_frame.
- while (IsValidFrame((uptr)frame, stack_top, bottom) &&
- IsAligned((uptr)frame, sizeof(*frame)) &&
+ while (IsValidFrame(bp, stack_top, bottom) && IsAligned(bp, sizeof(uhwptr)) &&
size < max_depth) {
- uhwptr pc1 = frame[15];
+ uhwptr pc1 = ((uhwptr *)bp)[15];
// Let's assume that any pointer in the 0th page is invalid and
// stop unwinding here. If we're adding support for a platform
// where this isn't true, we need to reconsider this check.
if (pc1 < kPageSize)
break;
if (pc1 != pc) {
- trace_buffer[size++] = (uptr) pc1;
+ // %o7 contains the address of the call instruction and not the
+ // return address, so we need to compensate.
+ trace_buffer[size++] = GetNextInstructionPc((uptr)pc1);
}
- bottom = (uptr)frame;
- frame = (uhwptr*)frame[14];
+ bottom = bp;
+ bp = (uptr)((uhwptr *)bp)[14] + STACK_BIAS;
}
}
} // namespace __sanitizer
-#endif // !defined(__sparcv8__) && !defined(__sparcv8) &&
- // !defined(__sparc_v8__)
+#endif // !defined(__sparc__)
Modified: compiler-rt/trunk/lib/sanitizer_common/sanitizer_unwind_linux_libcdep.cc
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/sanitizer_common/sanitizer_unwind_linux_libcdep.cc?rev=355965&r1=355964&r2=355965&view=diff
==============================================================================
--- compiler-rt/trunk/lib/sanitizer_common/sanitizer_unwind_linux_libcdep.cc (original)
+++ compiler-rt/trunk/lib/sanitizer_common/sanitizer_unwind_linux_libcdep.cc Tue Mar 12 13:31:53 2019
@@ -135,7 +135,13 @@ void BufferedStackTrace::UnwindSlow(uptr
if (to_pop == 0 && size > 1)
to_pop = 1;
PopStackFrames(to_pop);
+#if defined(__GNUC__) && defined(__sparc__)
+ // __builtin_return_address returns the address of the call instruction
+ // on the SPARC and not the return address, so we need to compensate.
+ trace_buffer[0] = GetNextInstructionPc(pc);
+#else
trace_buffer[0] = pc;
+#endif
}
void BufferedStackTrace::UnwindSlow(uptr pc, void *context, u32 max_depth) {
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