1 files changed, 85 insertions, 0 deletions
diff --git a/lib/sanitizer_common/sanitizer_stacktrace_sparc.cpp b/lib/sanitizer_common/sanitizer_stacktrace_sparc.cpp
new file mode 100644
index 000000000000..34190fb1bbb2
--- /dev/null
+++ b/lib/sanitizer_common/sanitizer_stacktrace_sparc.cpp
@@ -0,0 +1,85 @@
+//===-- sanitizer_stacktrace_sparc.cpp ------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This file is shared between AddressSanitizer and ThreadSanitizer
+// run-time libraries.
+//
+// Implemention of fast stack unwinding for Sparc.
+//===----------------------------------------------------------------------===//
+
+#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"
+
+namespace __sanitizer {
+
+void BufferedStackTrace::UnwindFast(uptr pc, uptr bp, uptr stack_top,
+                                    uptr stack_bottom, u32 max_depth) {
+  // 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");
+#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(bp, stack_top, bottom) && IsAligned(bp, sizeof(uhwptr)) &&
+         size < max_depth) {
+    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) {
+      // %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 = bp;
+    bp = (uptr)((uhwptr *)bp)[14] + STACK_BIAS;
+  }
+}
+
+}  // namespace __sanitizer
+
+#endif  // !defined(__sparc__)