Improve threading support further

test/libc/intrin/tls_test.c

@@ -0,0 +1,35 @@
+/*-*- 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 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/errno.h"
+#include "libc/intrin/threaded.h"
+#include "libc/runtime/runtime.h"
+#include "libc/testlib/testlib.h"
+
+static char tib[64];
+
+TEST(tls, test) {
+  errno = 31337;
+  EXPECT_EQ(31337, errno);
+  EXPECT_EQ(&__errno, __errno_location());
+  __initialize_tls(tib);
+  __install_tls(tib);
+  EXPECT_EQ(31337, errno);
+  EXPECT_EQ(tib, __get_tls());
+  EXPECT_EQ(tib + 0x3c, (char *)__errno_location());
+}

test/libc/rand/rand64_test.c

@@ -23,6 +23,7 @@
 #include "libc/dce.h"
 #include "libc/errno.h"
 #include "libc/intrin/spinlock.h"
+#include "libc/intrin/threaded.h"
 #include "libc/macros.internal.h"
 #include "libc/rand/rand.h"
 #include "libc/runtime/stack.h"
@@ -74,6 +75,7 @@ TEST(rand64, testLcg_doesntProduceIdenticalValues) {
 }
 
 TEST(rand64, testThreadSafety_doesntProduceIdenticalValues) {
+  char *tls[THREADS];
   sigset_t ss, oldss;
   void *stacks[THREADS];
   int i, j, rc, ws, tid[THREADS];
@@ -89,12 +91,14 @@ TEST(rand64, testThreadSafety_doesntProduceIdenticalValues) {
   }
   ready = false;
   for (i = 0; i < THREADS; ++i) {
+    tls[i] = calloc(1, 64);
+    __initialize_tls(tls[i]);
     stacks[i] = mmap(0, GetStackSize(), PROT_READ | PROT_WRITE,
                      MAP_STACK | MAP_ANONYMOUS, -1, 0);
     tid[i] =
         clone(Thrasher, stacks[i], GetStackSize(),
               CLONE_THREAD | CLONE_VM | CLONE_FS | CLONE_FILES | CLONE_SIGHAND,
-              (void *)(intptr_t)i, 0, 0, 0, 0);
+              (void *)(intptr_t)i, 0, tls[i], 64, 0);
     ASSERT_NE(-1, tid[i]);
   }
   ready = true;
@@ -113,4 +117,7 @@ TEST(rand64, testThreadSafety_doesntProduceIdenticalValues) {
   for (i = 0; i < THREADS; ++i) {
     EXPECT_SYS(0, 0, munmap(stacks[i], GetStackSize()));
   }
+  for (i = 0; i < THREADS; ++i) {
+    free(tls[i]);
+  }
 }

test/libc/runtime/clone_test.c

@@ -21,6 +21,7 @@
 #include "libc/errno.h"
 #include "libc/intrin/kprintf.h"
 #include "libc/intrin/spinlock.h"
+#include "libc/intrin/threaded.h"
 #include "libc/mem/mem.h"
 #include "libc/runtime/stack.h"
 #include "libc/sysv/consts/clone.h"
@@ -31,7 +32,7 @@
 #include "libc/time/time.h"
 
 char *stack, *tls;
-int x, me, thechilde;
+int x, me, tid, thechilde;
 _Alignas(64) volatile char lock;
 
 void SetUp(void) {
@@ -39,9 +40,8 @@ void SetUp(void) {
   lock = 0;
   me = gettid();
   thechilde = 0;
-  tls = calloc(1, 512);
-  *(intptr_t *)tls = (intptr_t)tls;
-  *(intptr_t *)(tls + 0x30) = (intptr_t)tls;
+  tls = calloc(1, 64);
+  __initialize_tls(tls);
   *(int *)(tls + 0x3c) = 31337;
   ASSERT_NE(MAP_FAILED, (stack = mmap(0, GetStackSize(), PROT_READ | PROT_WRITE,
                                       MAP_STACK | MAP_ANONYMOUS, -1, 0)));
@@ -75,15 +75,12 @@ int DoNothing(void *arg) {
   return 0;
 }
 
-void __setup_tls(void);
-
 TEST(clone, test1) {
-  int tid;
   _spinlock(&lock);
   ASSERT_NE(-1, (tid = clone(CloneTest1, stack, GetStackSize(),
                              CLONE_THREAD | CLONE_VM | CLONE_FS | CLONE_FILES |
                                  CLONE_SIGHAND | CLONE_SETTLS,
-                             (void *)23, 0, tls, 512, 0)));
+                             (void *)23, 0, tls, 64, 0)));
   _spinlock(&lock);
   ASSERT_EQ(42, x);
   ASSERT_NE(me, tid);
@@ -91,13 +88,27 @@ TEST(clone, test1) {
   ASSERT_EQ(0, errno);
   errno = 31337;
   ASSERT_EQ(31337, errno);
-
-  return;
-  intptr_t *p;
-  asm("movq\t%%fs:0x30,%0" : "=a"(p));
-  kprintf("%fs:0x30 = %p\n", p);
-  for (int i = 0; i < 64; ++i) {
-    kprintf("0x%.5x = %p\n", i * 8, p[i]);
-  }
-  kprintf("\n");
+  errno = 0;
+}
+
+int CloneTestSys(void *arg) {
+  thechilde = gettid();
+  ASSERT_EQ(31337, errno);
+  open(0, 0);
+  ASSERT_EQ(EFAULT, errno);
+  _spunlock(&lock);
+  return 0;
+}
+
+TEST(clone, tlsSystemCallsErrno_wontClobberMainThreadBecauseTls) {
+  ASSERT_EQ(0, errno);
+  ASSERT_EQ(31337, *(int *)(tls + 0x3c));
+  _spinlock(&lock);
+  ASSERT_NE(-1, (tid = clone(CloneTestSys, stack, GetStackSize(),
+                             CLONE_THREAD | CLONE_VM | CLONE_FS | CLONE_FILES |
+                                 CLONE_SIGHAND | CLONE_SETTLS,
+                             (void *)23, 0, tls, 64, 0)));
+  _spinlock(&lock);
+  ASSERT_EQ(0, errno);
+  ASSERT_EQ(EFAULT, *(int *)(tls + 0x3c));
 }