diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_linux.cpp b/compiler-rt/lib/sanitizer_common/sanitizer_linux.cpp
index 6359f4348e3c4..1da3ce763302e 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_linux.cpp
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_linux.cpp
@@ -107,7 +107,9 @@ extern struct ps_strings *__ps_strings;
 #  endif  // SANITIZER_NETBSD
 
 #  if SANITIZER_SOLARIS
+#    include <stddef.h>
 #    include <stdlib.h>
+#    include <sys/frame.h>
 #    include <thread.h>
 #    define environ _environ
 #  endif
@@ -2617,7 +2619,19 @@ static void GetPcSpBp(void *context, uptr *pc, uptr *sp, uptr *bp) {
 #    if SANITIZER_SOLARIS
   ucontext_t *ucontext = (ucontext_t *)context;
   *pc = ucontext->uc_mcontext.gregs[REG_PC];
-  *sp = ucontext->uc_mcontext.gregs[REG_O6] + STACK_BIAS;
+  *sp = ucontext->uc_mcontext.gregs[REG_SP] + STACK_BIAS;
+  // Avoid SEGV when dereferencing sp on stack overflow with non-faulting load.
+  // This requires a SPARC V9 CPU.  Cannot use #ASI_PNF here: only supported
+  // since clang-19.
+#      if defined(__sparcv9)
+  asm("ldxa [%[fp]] 0x82, %[bp]"
+#      else
+  asm("lduwa [%[fp]] 0x82, %[bp]"
+#      endif
+      : [bp] "=r"(*bp)
+      : [fp] "r"(&((struct frame *)*sp)->fr_savfp));
+  if (*bp)
+    *bp += STACK_BIAS;
 #    else
   // Historical BSDism here.
   struct sigcontext *scontext = (struct sigcontext *)context;
@@ -2628,8 +2642,8 @@ static void GetPcSpBp(void *context, uptr *pc, uptr *sp, uptr *bp) {
   *pc = scontext->si_regs.pc;
   *sp = scontext->si_regs.u_regs[14];
 #      endif
-#    endif
   *bp = (uptr)((uhwptr *)*sp)[14] + STACK_BIAS;
+#    endif
 #  elif defined(__mips__)
   ucontext_t *ucontext = (ucontext_t *)context;
   *pc = ucontext->uc_mcontext.pc;
diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_symbolizer_report.cpp b/compiler-rt/lib/sanitizer_common/sanitizer_symbolizer_report.cpp
index ffbaf1468ec8f..351e00db6fb2d 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_symbolizer_report.cpp
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_symbolizer_report.cpp
@@ -227,12 +227,15 @@ static void ReportStackOverflowImpl(const SignalContext &sig, u32 tid,
          SanitizerToolName, kDescription, (void *)sig.addr, (void *)sig.pc,
          (void *)sig.bp, (void *)sig.sp, tid);
   Printf("%s", d.Default());
-  InternalMmapVector<BufferedStackTrace> stack_buffer(1);
-  BufferedStackTrace *stack = stack_buffer.data();
-  stack->Reset();
-  unwind(sig, unwind_context, stack);
-  stack->Print();
-  ReportErrorSummary(kDescription, stack);
+  // Avoid SEGVs in the unwinder when bp couldn't be determined.
+  if (sig.bp) {
+    InternalMmapVector<BufferedStackTrace> stack_buffer(1);
+    BufferedStackTrace *stack = stack_buffer.data();
+    stack->Reset();
+    unwind(sig, unwind_context, stack);
+    stack->Print();
+    ReportErrorSummary(kDescription, stack);
+  }
 }
 
 static void ReportDeadlySignalImpl(const SignalContext &sig, u32 tid,