Fix some todos

ape/ape-m1.c

@@ -22,6 +22,7 @@
 #include <libkern/OSCacheControl.h>
 #include <limits.h>
 #include <pthread.h>
+#include <semaphore.h>
 #include <signal.h>
 #include <stdarg.h>
 #include <stdint.h>
@@ -30,7 +31,6 @@
 #include <sys/uio.h>
 #include <time.h>
 #include <unistd.h>
-#include <semaphore.h>
 
 #define pagesz         16384
 #define SYSLIB_MAGIC   ('s' | 'l' << 8 | 'i' << 16 | 'b' << 24)
@@ -89,6 +89,8 @@ struct Syslib {
   long (*sem_post)(int *);
   long (*sem_wait)(int *);
   long (*sem_trywait)(int *);
+  long (*getrlimit)(int, struct rlimit *);
+  long (*setrlimit)(int, const struct rlimit *);
 };
 
 #define ELFCLASS32  1
@@ -814,7 +816,8 @@ static long sys_getentropy(void *buf, size_t buflen) {
   return sysret(getentropy(buf, buflen));
 }
 
-static long sys_sem_open(const char *name, int oflags, mode_t mode, unsigned value) {
+static long sys_sem_open(const char *name, int oflags, mode_t mode,
+                         unsigned value) {
   return sysret((long)sem_open(name, oflags, mode, value));
 }
 
@@ -838,6 +841,14 @@ static long sys_sem_trywait(sem_t *sem) {
   return sysret(sem_trywait(sem));
 }
 
+static long sys_getrlimit(int which, struct rlimit *rlim) {
+  return sysret(getrlimit(which, rlim));
+}
+
+static long sys_setrlimit(int which, const struct rlimit *rlim) {
+  return sysret(setrlimit(which, rlim));
+}
+
 static long sys_write(int fd, const void *data, size_t size) {
   return sysret(write(fd, data, size));
 }
@@ -930,6 +941,8 @@ int main(int argc, char **argv, char **envp) {
   M->lib.sem_post = sys_sem_post;
   M->lib.sem_wait = sys_sem_wait;
   M->lib.sem_trywait = sys_sem_trywait;
+  M->lib.getrlimit = sys_getrlimit;
+  M->lib.setrlimit = sys_setrlimit;
 
   /* getenv("_") is close enough to at_execfn */
   execfn = argc > 0 ? argv[0] : 0;

libc/calls/clock_nanosleep.c

@@ -100,7 +100,7 @@ static int cosmo_clock_nanosleep(int clock, int flags,
   if (timespec_cmp(remain, quantum) > 0) {
     waitfor = timespec_sub(remain, quantum);
     if (sys_clock_nanosleep(sleep_clock, 0, &waitfor, rem) == -1) {
-      if (rem && errno == EINTR) {
+      if (!flags && rem && errno == EINTR) {
         *rem = timespec_add(*rem, quantum);
       }
       return -1;

libc/calls/diagnose_syscall.S

@@ -1,110 +0,0 @@
-/*-*- mode:unix-assembly; indent-tabs-mode:t; tab-width:8; coding:utf-8     -*-│
-│vi: set et ft=asm ts=8 tw=8 fenc=utf-8                                     :vi│
-╞══════════════════════════════════════════════════════════════════════════════╡
-│ Copyright 2022 Justine Alexandra Roberts Tunney                              │
-│                                                                              │
-│ Permission to use, copy, modify, and/or distribute this software for         │
-│ any purpose with or without fee is hereby granted, provided that the         │
-│ above copyright notice and this permission notice appear in all copies.      │
-│                                                                              │
-│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL                │
-│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED                │
-│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE             │
-│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL         │
-│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR        │
-│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER               │
-│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
-│ PERFORMANCE OF THIS SOFTWARE.                                                │
-╚─────────────────────────────────────────────────────────────────────────────*/
-#include "libc/macros.internal.h"
-.privileged
-
-diagnose_syscall:
-	push	%rbp
-	mov	%rsp,%rbp
-	push	%rbx
-	push	%r12
-	push	%r13
-	push	%r14
-	push	%r15
-
-	mov	$0x7fffffff,%eax
-	add	$4,%eax				# set sf/of/pf
-
-	mov	%rdi,%rax			# nr
-	mov	%rsi,%rdi			# arg 1
-	mov	%rdx,%rsi			# arg 2
-	mov	%rcx,%rdx			# arg 3
-	mov	%r8,%r10			# arg 4
-	mov	%r9,%r8				# arg 5
-	mov	16(%rbp),%r9			# arg 6
-	push	24(%rbp)			# arg 7
-	push	%rax				# fake ret addr
-	mov	32(%rbp),%r12			# ucontext before
-	mov	40(%rbp),%r13			# ucontext after
-	xor	%ecx,%ecx
-	xor	%r11d,%r11d
-	mov	$0x5555555555555555,%r11
-	mov	$0x5555555555555555,%r14
-	mov	$0x5555555555555555,%r15
-	mov	$0x5555555555555555,%rbx
-
-//	save machine state before system call
-	pushf
-	pop	176(%r12)
-	mov	%r8,40(%r12)
-	mov	%r9,48(%r12)
-	mov	%r10,56(%r12)
-	mov	%r11,64(%r12)
-	mov	%r12,72(%r12)
-	mov	%r13,80(%r12)
-	mov	%r14,88(%r12)
-	mov	%r15,96(%r12)
-	mov	%rdi,104(%r12)
-	mov	%rsi,112(%r12)
-	mov	%rbp,120(%r12)
-	mov	%rbx,128(%r12)
-	mov	%rdx,136(%r12)
-	mov	%rax,144(%r12)
-	mov	%rcx,152(%r12)
-	push	%rbx
-	lea	320(%r12),%rbx
-	mov	%rbx,224(%r12)			# set fpregs ptr
-	pop	%rbx
-
-	syscall
-
-//	save machine state after system call
-	pushf
-	pop	176(%r13)
-	mov	%r8,40(%r13)
-	mov	%r9,48(%r13)
-	mov	%r10,56(%r13)
-	mov	%r11,64(%r13)
-	mov	%r12,72(%r13)
-	mov	%r13,80(%r13)
-	mov	%r14,88(%r13)
-	mov	%r15,96(%r13)
-	mov	%rdi,104(%r13)
-	mov	%rsi,112(%r13)
-	mov	%rbp,120(%r13)
-	mov	%rbx,128(%r13)
-	mov	%rdx,136(%r13)
-	mov	%rax,144(%r13)
-	mov	%rcx,152(%r13)
-	push	%rbx
-	lea	320(%r13),%rbx
-	mov	%rbx,224(%r13)			# set fpregs ptr
-	pop	%rbx
-
-	pop	%r13
-	pop	%r13
-
-	pop	%r15
-	pop	%r14
-	pop	%r13
-	pop	%r12
-	pop	%rbx
-	pop	%rbp
-	ret
-	.endfn	diagnose_syscall,globl

libc/calls/getrlimit.c

@@ -18,11 +18,13 @@
 ╚─────────────────────────────────────────────────────────────────────────────*/
 #include "libc/calls/calls.h"
 #include "libc/calls/struct/rlimit.internal.h"
+#include "libc/calls/syscall-sysv.internal.h"
 #include "libc/dce.h"
 #include "libc/intrin/asan.internal.h"
 #include "libc/intrin/describeflags.internal.h"
 #include "libc/intrin/strace.internal.h"
 #include "libc/runtime/stack.h"
+#include "libc/runtime/syslib.internal.h"
 #include "libc/sysv/consts/rlimit.h"
 #include "libc/sysv/errfuns.h"
 
@@ -40,6 +42,8 @@ int getrlimit(int resource, struct rlimit *rlim) {
     rc = einval();
   } else if (!rlim || (IsAsan() && !__asan_is_valid(rlim, sizeof(*rlim)))) {
     rc = efault();
+  } else if (IsXnuSilicon()) {
+    rc = _sysret(__syslib->__getrlimit(resource, rlim));
   } else if (!IsWindows()) {
     rc = sys_getrlimit(resource, rlim);
   } else if (resource == RLIMIT_STACK) {

libc/calls/read-nt.c

@@ -342,23 +342,26 @@ static textwindows int ProcessMouseEvent(const struct NtInputRecord *r,
   bs &= kNtFromLeft1stButtonPressed | kNtRightmostButtonPressed;
   if (ev & kNtMouseWheeled) {
     // scroll wheel (unnatural mode)
-    if (!(r->Event.MouseEvent.dwControlKeyState &
+    bool isup = ((int)r->Event.MouseEvent.dwButtonState >> 16) > 0;
-          (kNtShiftPressed | kNtLeftCtrlPressed | kNtRightCtrlPressed |
+    if (__ttyconf.magic & kTtyXtMouse) {
-           kNtLeftAltPressed | kNtRightAltPressed))) {
+      if (r->Event.MouseEvent.dwControlKeyState &
-      bool isup = ((int)r->Event.MouseEvent.dwButtonState >> 16) > 0;
+          (kNtLeftCtrlPressed | kNtRightCtrlPressed)) {
-      if (__ttyconf.magic & kTtyXtMouse) {
         e = isup ? 80 : 81;
-        goto OutputXtermMouseEvent;
       } else {
-        // we disable mouse highlighting when the tty is put in raw mode
+        e = isup ? 64 : 65;
-        // to mouse wheel events with widely understood vt100 arrow keys
+      }
-        *p++ = 033;
+      goto OutputXtermMouseEvent;
-        *p++ = !__keystroke.ohno_decckm ? '[' : 'O';
+    } else if (!(r->Event.MouseEvent.dwControlKeyState &
-        if (isup) {
+                 (kNtShiftPressed | kNtLeftCtrlPressed | kNtRightCtrlPressed |
-          *p++ = 'A';
+                  kNtLeftAltPressed | kNtRightAltPressed))) {
-        } else {
+      // we disable mouse highlighting when the tty is put in raw mode
-          *p++ = 'B';
+      // to mouse wheel events with widely understood vt100 arrow keys
-        }
+      *p++ = 033;
+      *p++ = !__keystroke.ohno_decckm ? '[' : 'O';
+      if (isup) {
+        *p++ = 'A';
+      } else {
+        *p++ = 'B';
       }
     }
   } else if ((bs || currentbs) && (__ttyconf.magic & kTtyXtMouse)) {

libc/calls/setrlimit.c

@@ -19,11 +19,13 @@
 #include "libc/assert.h"
 #include "libc/calls/calls.h"
 #include "libc/calls/struct/rlimit.internal.h"
+#include "libc/calls/syscall-sysv.internal.h"
 #include "libc/dce.h"
 #include "libc/intrin/asan.internal.h"
 #include "libc/intrin/describeflags.internal.h"
 #include "libc/intrin/strace.internal.h"
 #include "libc/macros.internal.h"
+#include "libc/runtime/syslib.internal.h"
 #include "libc/sysv/consts/rlimit.h"
 #include "libc/sysv/errfuns.h"
 
@@ -79,6 +81,8 @@ int setrlimit(int resource, const struct rlimit *rlim) {
     rc = einval();
   } else if (!rlim || (IsAsan() && !__asan_is_valid(rlim, sizeof(*rlim)))) {
     rc = efault();
+  } else if (IsXnuSilicon()) {
+    rc = _sysret(__syslib->__setrlimit(resource, rlim));
   } else if (!IsWindows()) {
     rc = sys_setrlimit(resource, rlim);
     if (IsXnu() && !rc && resource == RLIMIT_AS) {

libc/runtime/syslib.internal.h

@@ -68,6 +68,8 @@ struct Syslib {
   long (*__sem_post)(int *);
   long (*__sem_wait)(int *);
   long (*__sem_trywait)(int *);
+  long (*__getrlimit)(int, void *);
+  long (*__setrlimit)(int, const void *);
 };
 
 extern struct Syslib *__syslib;

libc/thread/tls.h

@@ -3,8 +3,7 @@
 
 #define TLS_ALIGNMENT 64
 
-#define TIB_FLAG_VFORKED     1
+#define TIB_FLAG_VFORKED 1
-#define TIB_FLAG_WINCRASHING 2
 
 #if !(__ASSEMBLER__ + __LINKER__ + 0)
 COSMOPOLITAN_C_START_

test/libc/calls/clock_nanosleep_test.c

@@ -32,10 +32,6 @@
 #include "libc/testlib/testlib.h"
 #include "libc/time/time.h"
 
-void SetUpOnce(void) {
-  if (!IsWindows()) _Exit(0);
-}
-
 void OnAlrm(int sig) {
   // do nothing
   STRACE("OnAlrm()");

test/libc/calls/stackoverflow1_test.c

@@ -0,0 +1,108 @@
+/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
+│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8                                :vi│
+╞══════════════════════════════════════════════════════════════════════════════╡
+│ Copyright 2023 Justine Alexandra Roberts Tunney                              │
+│                                                                              │
+│ Permission to use, copy, modify, and/or distribute this software for         │
+│ any purpose with or without fee is hereby granted, provided that the         │
+│ above copyright notice and this permission notice appear in all copies.      │
+│                                                                              │
+│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL                │
+│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED                │
+│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE             │
+│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL         │
+│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR        │
+│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER               │
+│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
+│ PERFORMANCE OF THIS SOFTWARE.                                                │
+╚─────────────────────────────────────────────────────────────────────────────*/
+#include "libc/calls/struct/rlimit.h"
+#include "libc/calls/struct/sigaction.h"
+#include "libc/calls/struct/sigaltstack.h"
+#include "libc/calls/struct/siginfo.h"
+#include "libc/dce.h"
+#include "libc/intrin/kprintf.h"
+#include "libc/limits.h"
+#include "libc/mem/gc.internal.h"
+#include "libc/mem/mem.h"
+#include "libc/runtime/runtime.h"
+#include "libc/runtime/sysconf.h"
+#include "libc/sysv/consts/rlimit.h"
+#include "libc/sysv/consts/sa.h"
+#include "libc/sysv/consts/sig.h"
+#include "libc/sysv/consts/ss.h"
+#include "libc/testlib/testlib.h"
+#include "libc/thread/thread.h"
+
+/**
+ * stack overflow recovery technique #1
+ * overflow the gigantic main process stack
+ * simple but it can upset kernels / libraries
+ */
+
+jmp_buf recover;
+volatile bool smashed_stack;
+
+void CrashHandler(int sig, siginfo_t *si, void *ctx) {
+  struct sigaltstack ss;
+  ASSERT_SYS(0, 0, sigaltstack(0, &ss));
+  ASSERT_EQ(SS_ONSTACK, ss.ss_flags);
+  kprintf("kprintf avoids overflowing %G %p\n", si->si_signo, si->si_addr);
+  smashed_stack = true;
+  ASSERT_TRUE(__is_stack_overflow(si, ctx));
+  longjmp(recover, 123);
+}
+
+void SetUp(void) {
+
+  // tune down the main process's stack size to a reasonable amount
+  // some operating systems, e.g. freebsd, will do things like have
+  // 500mb RLIMIT_STACK by default, even on machines with 400mb RAM
+  struct rlimit rl = {2 * 1024 * 1024, 2 * 1024 * 1024};
+  if (!IsWindows() && !IsXnu()) {
+    ASSERT_SYS(0, 0, setrlimit(RLIMIT_STACK, &rl));
+  }
+
+  // set up the signal handler and alternative stack
+  struct sigaction sa;
+  struct sigaltstack ss;
+  ss.ss_flags = 0;
+  ss.ss_size = sysconf(_SC_MINSIGSTKSZ) + 8192;
+  ss.ss_sp = _mapanon(ss.ss_size);
+  ASSERT_SYS(0, 0, sigaltstack(&ss, 0));
+  sa.sa_flags = SA_SIGINFO | SA_ONSTACK;  // <-- important
+  sigemptyset(&sa.sa_mask);
+  sa.sa_sigaction = CrashHandler;
+  sigaction(SIGBUS, &sa, 0);
+  sigaction(SIGSEGV, &sa, 0);
+}
+
+int StackOverflow(int f(), int n) {
+  if (n < INT_MAX) {
+    return f(f, n + 1) - 1;
+  } else {
+    return INT_MAX;
+  }
+}
+
+int (*pStackOverflow)(int (*)(), int) = StackOverflow;
+
+TEST(stackoverflow, standardStack_altStack_process_longjmp) {
+  if (IsTiny()) return;  // TODO(jart): why?
+
+  int jumpcode;
+  if (!(jumpcode = setjmp(recover))) {
+    exit(pStackOverflow(pStackOverflow, 0));
+  }
+  ASSERT_EQ(123, jumpcode);
+  ASSERT_TRUE(smashed_stack);
+
+  // here's where longjmp() gets us into trouble
+  struct sigaltstack ss;
+  ASSERT_SYS(0, 0, sigaltstack(0, &ss));
+  if (IsXnu() || IsNetbsd()) {
+    ASSERT_EQ(SS_ONSTACK, ss.ss_flags);  // wut
+  } else {
+    ASSERT_EQ(0, ss.ss_flags);
+  }
+}

test/libc/calls/stackoverflow2_test.c

@@ -0,0 +1,105 @@
+/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
+│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8                                :vi│
+╞══════════════════════════════════════════════════════════════════════════════╡
+│ Copyright 2023 Justine Alexandra Roberts Tunney                              │
+│                                                                              │
+│ Permission to use, copy, modify, and/or distribute this software for         │
+│ any purpose with or without fee is hereby granted, provided that the         │
+│ above copyright notice and this permission notice appear in all copies.      │
+│                                                                              │
+│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL                │
+│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED                │
+│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE             │
+│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL         │
+│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR        │
+│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER               │
+│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
+│ PERFORMANCE OF THIS SOFTWARE.                                                │
+╚─────────────────────────────────────────────────────────────────────────────*/
+#include "libc/calls/struct/sigaction.h"
+#include "libc/calls/struct/sigaltstack.h"
+#include "libc/calls/struct/siginfo.h"
+#include "libc/dce.h"
+#include "libc/intrin/kprintf.h"
+#include "libc/limits.h"
+#include "libc/mem/gc.internal.h"
+#include "libc/mem/mem.h"
+#include "libc/runtime/runtime.h"
+#include "libc/runtime/sysconf.h"
+#include "libc/sysv/consts/sa.h"
+#include "libc/sysv/consts/sig.h"
+#include "libc/sysv/consts/ss.h"
+#include "libc/testlib/testlib.h"
+#include "libc/thread/thread.h"
+
+/**
+ * stack overflow recovery technique #2
+ * longjmp out of signal back into thread
+ * simple but it can upset kernels / libraries
+ */
+
+jmp_buf recover;
+volatile bool smashed_stack;
+
+void CrashHandler(int sig, siginfo_t *si, void *ctx) {
+  struct sigaltstack ss;
+  ASSERT_SYS(0, 0, sigaltstack(0, &ss));
+  ASSERT_EQ(SS_ONSTACK, ss.ss_flags);
+  kprintf("kprintf avoids overflowing %G %p\n", si->si_signo, si->si_addr);
+  smashed_stack = true;
+  ASSERT_TRUE(__is_stack_overflow(si, ctx));
+  longjmp(recover, 123);
+}
+
+int StackOverflow(int f(), int n) {
+  if (n < INT_MAX) {
+    return f(f, n + 1) - 1;
+  } else {
+    return INT_MAX;
+  }
+}
+
+int (*pStackOverflow)(int (*)(), int) = StackOverflow;
+
+void *MyPosixThread(void *arg) {
+  int jumpcode;
+  struct sigaction sa, o1, o2;
+  struct sigaltstack ss;
+  ss.ss_flags = 0;
+  ss.ss_size = sysconf(_SC_MINSIGSTKSZ) + 4096;
+  ss.ss_sp = gc(malloc(ss.ss_size));
+  ASSERT_SYS(0, 0, sigaltstack(&ss, 0));
+  sa.sa_flags = SA_SIGINFO | SA_ONSTACK;  // <-- important
+  sigemptyset(&sa.sa_mask);
+  sa.sa_sigaction = CrashHandler;
+  sigaction(SIGBUS, &sa, &o1);
+  sigaction(SIGSEGV, &sa, &o2);
+  if (!(jumpcode = setjmp(recover))) {
+    exit(pStackOverflow(pStackOverflow, 0));
+  }
+  ASSERT_EQ(123, jumpcode);
+  sigaction(SIGSEGV, &o2, 0);
+  sigaction(SIGBUS, &o1, 0);
+  // here's where longjmp() gets us into trouble
+  ASSERT_SYS(0, 0, sigaltstack(0, &ss));
+  if (IsXnu() || IsNetbsd()) {
+    ASSERT_EQ(SS_ONSTACK, ss.ss_flags);  // wut
+  } else {
+    ASSERT_EQ(0, ss.ss_flags);
+  }
+  return 0;
+}
+
+TEST(stackoverflow, standardStack_altStack_thread_longjmp) {
+  pthread_t th;
+  struct sigaltstack ss;
+  for (int i = 0; i < 2; ++i) {
+    smashed_stack = false;
+    pthread_create(&th, 0, MyPosixThread, 0);
+    pthread_join(th, 0);
+    ASSERT_TRUE(smashed_stack);
+    // this should be SS_DISABLE but ShowCrashReports() creates an alt stack
+    ASSERT_SYS(0, 0, sigaltstack(0, &ss));
+    ASSERT_EQ(0, ss.ss_flags);
+  }
+}

test/libc/thread/makecontext_test.c

@@ -31,10 +31,9 @@
 #include "libc/x/x.h"
 #include "third_party/libcxx/math.h"
 
-#if 0  // TODO(jart): fix me
-
 bool gotsome;
 ucontext_t uc, goback;
+extern long __klog_handle;
 
 void SetUpOnce(void) {
   testlib_enable_tmp_setup_teardown();
@@ -90,18 +89,17 @@ TEST(makecontext, backtrace) {
   SPAWN(fork);
   ASSERT_SYS(0, 0, close(2));
   ASSERT_SYS(0, 2, creat("log", 0644));
+  __klog_handle = 2;
   getcontext(&uc);
   uc.uc_link = 0;
   uc.uc_stack.ss_sp = NewCosmoStack();
   uc.uc_stack.ss_size = GetStackSize();
   makecontext(&uc, itsatrap, 2, 123, 456);
   setcontext(&uc);
-  EXITS(128 + SIGSEGV);
+  TERMS(SIGSEGV);
   if (!GetSymbolTable()) return;
   char *log = gc(xslurp("log", 0));
   EXPECT_NE(0, strstr(log, "itsatrap"));
   EXPECT_NE(0, strstr(log, "runcontext"));
   EXPECT_NE(0, strstr(log, "makecontext_backtrace"));
 }
-
-#endif