diff --git a/libc/Android.bp b/libc/Android.bp
index 61ef29d..4a4426d 100644
--- a/libc/Android.bp
+++ b/libc/Android.bp
@@ -954,7 +954,6 @@
                 "arch-x86/bionic/__bionic_clone.S",
                 "arch-x86/bionic/_exit_with_stack_teardown.S",
                 "arch-x86/bionic/libcrt_compat.c",
-                "arch-x86/bionic/__restore.S",
                 "arch-x86/bionic/setjmp.S",
                 "arch-x86/bionic/syscall.S",
                 "arch-x86/bionic/vfork.S",
diff --git a/libc/arch-x86/bionic/__restore.S b/libc/arch-x86/bionic/__restore.S
deleted file mode 100644
index 10ab8e5..0000000
--- a/libc/arch-x86/bionic/__restore.S
+++ /dev/null
@@ -1,91 +0,0 @@
-/*
- * Copyright (C) 2014 The Android Open Source Project
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- *  * Redistributions of source code must retain the above copyright
- *    notice, this list of conditions and the following disclaimer.
- *  * Redistributions in binary form must reproduce the above copyright
- *    notice, this list of conditions and the following disclaimer in
- *    the documentation and/or other materials provided with the
- *    distribution.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
- * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
- * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
- * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
- * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
- * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
- * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
- * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
- * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
- * SUCH DAMAGE.
- */
-
-#include <private/bionic_asm.h>
-#include <private/bionic_asm_dwarf_exprs.h>
-
-// Offsets into struct sigcontext.
-#define OFFSET_EDI 16
-#define OFFSET_ESI 20
-#define OFFSET_EBP 24
-#define OFFSET_ESP 28
-#define OFFSET_EBX 32
-#define OFFSET_EDX 36
-#define OFFSET_ECX 40
-#define OFFSET_EAX 44
-#define OFFSET_EIP 56
-
-// Non-standard DWARF constants for the x86 registers.
-#define DW_x86_REG_EAX 0
-#define DW_x86_REG_ECX 1
-#define DW_x86_REG_EDX 2
-#define DW_x86_REG_EBX 3
-#define DW_x86_REG_ESP 4
-#define DW_x86_REG_EBP 5
-#define DW_x86_REG_ESI 6
-#define DW_x86_REG_EDI 7
-#define DW_x86_REG_EIP 8
-
-#define RESTORE_GPR(reg, extra_offset)                    \
-    m_cfi_breg_offset DW_x86_REG_ ## reg,                 \
-                      DW_x86_REG_ESP,                     \
-                      (OFFSET_ ## reg + (extra_offset));
-
-// Restoring ESP is unnecessary as the unwinder simply uses the CFA value.
-#define RESTORE_GPRS(extra_offset)                                      \
-    m_cfi_def_cfa_deref DW_x86_REG_ESP, (OFFSET_ESP + (extra_offset));  \
-    RESTORE_GPR(EDI, extra_offset)                                      \
-    RESTORE_GPR(ESI, extra_offset)                                      \
-    RESTORE_GPR(EBP, extra_offset)                                      \
-    RESTORE_GPR(EBX, extra_offset)                                      \
-    RESTORE_GPR(EDX, extra_offset)                                      \
-    RESTORE_GPR(ECX, extra_offset)                                      \
-    RESTORE_GPR(EAX, extra_offset)                                      \
-    RESTORE_GPR(EIP, extra_offset)                                      \
-
-  .text
-
-  .cfi_startproc
-  .cfi_signal_frame
-  RESTORE_GPRS(4)
-  nop   // See comment in libc/arch-x86_64/bionic/__restore_rt.S about this nop.
-ENTRY_NO_DWARF_PRIVATE(__restore)
-  popl %eax
-  RESTORE_GPRS(0)
-  movl $__NR_sigreturn, %eax
-  int $0x80
-END(__restore)  // Not END_NO_DWARF because we _manually_ set up CFI.
-
-  .cfi_startproc
-  .cfi_signal_frame
-  RESTORE_GPRS(160)
-  nop   // See comment in libc/arch-x86_64/bionic/__restore_rt.S about this nop.
-ENTRY_NO_DWARF_PRIVATE(__restore_rt)
-  movl $__NR_rt_sigreturn, %eax
-  int $0x80
-END(__restore_rt)  // Not END_NO_DWARF because we _manually_ set up CFI.
diff --git a/libc/bionic/sigaction.cpp b/libc/bionic/sigaction.cpp
index 1cdb021..a84886b 100644
--- a/libc/bionic/sigaction.cpp
+++ b/libc/bionic/sigaction.cpp
@@ -39,26 +39,25 @@
 extern "C" int __rt_sigaction(int, const struct __kernel_sigaction*, struct __kernel_sigaction*, size_t);
 
 int sigaction(int signal, const struct sigaction* bionic_new_action, struct sigaction* bionic_old_action) {
-  __kernel_sigaction kernel_new_action;
+  __kernel_sigaction kernel_new_action = {};
   if (bionic_new_action != nullptr) {
     kernel_new_action.sa_flags = bionic_new_action->sa_flags;
     kernel_new_action.sa_handler = bionic_new_action->sa_handler;
     // Don't filter signals here; if the caller asked for everything to be blocked, we should obey.
     kernel_new_action.sa_mask = bionic_new_action->sa_mask;
-#if defined(SA_RESTORER)
+#if defined(__x86_64__)
+    // riscv64 doesn't have sa_restorer. For arm64 and 32-bit x86, unwinding
+    // works best if you just let the kernel supply the default restorer
+    // from [vdso]. gdb doesn't care, but libgcc needs the nop that the
+    // kernel includes before the actual code. (We could add that ourselves,
+    // but why bother?)
+    // TODO: why do arm32 and x86-64 need this to unwind through signal handlers?
     kernel_new_action.sa_restorer = bionic_new_action->sa_restorer;
-#if defined(__aarch64__)
-    // arm64 has sa_restorer, but unwinding works best if you just let the
-    // kernel supply the default restorer from [vdso]. gdb doesn't care, but
-    // libgcc needs the nop that the kernel includes before the actual code.
-    // (We could add that ourselves, but why bother?)
-#else
     if (!(kernel_new_action.sa_flags & SA_RESTORER)) {
       kernel_new_action.sa_flags |= SA_RESTORER;
       kernel_new_action.sa_restorer = &__restore_rt;
     }
 #endif
-#endif
   }
 
   __kernel_sigaction kernel_old_action;
@@ -90,10 +89,11 @@
 // by extracting the implementation of sigaction64 to a static function.
 static int __sigaction64(int signal, const struct sigaction64* bionic_new,
                          struct sigaction64* bionic_old) {
-  struct sigaction64 kernel_new;
+  struct sigaction64 kernel_new = {};
   if (bionic_new) {
     kernel_new = *bionic_new;
-#if defined(SA_RESTORER)
+#if defined(__arm__)
+    // (See sa_restorer comment in sigaction() above.)
     if (!(kernel_new.sa_flags & SA_RESTORER)) {
       kernel_new.sa_flags |= SA_RESTORER;
       kernel_new.sa_restorer = (kernel_new.sa_flags & SA_SIGINFO) ? &__restore_rt : &__restore;
@@ -110,9 +110,8 @@
 int sigaction(int signal, const struct sigaction* bionic_new, struct sigaction* bionic_old) {
   // The 32-bit ABI is broken. struct sigaction includes a too-small sigset_t,
   // so we have to translate to struct sigaction64 first.
-  struct sigaction64 kernel_new;
+  struct sigaction64 kernel_new = {};
   if (bionic_new) {
-    kernel_new = {};
     kernel_new.sa_flags = bionic_new->sa_flags;
     kernel_new.sa_handler = bionic_new->sa_handler;
 #if defined(SA_RESTORER)