Snap for 6488384 from 7501c6de1a6a4474f78b3296460d4fa2d099b9d4 to rvc-release

Change-Id: I05323a6f41f8280f7f0e68eead5b89179115c169

7 files changed, 70 insertions, 15 deletions

diff --git a/libc/arch-arm/bionic/vfork.S b/libc/arch-arm/bionic/vfork.S
index 6855db74b..a964be53a 100644
--- a/libc/arch-arm/bionic/vfork.S
+++ b/libc/arch-arm/bionic/vfork.S
@@ -31,17 +31,27 @@
 
 ENTRY(vfork)
 __BIONIC_WEAK_ASM_FOR_NATIVE_BRIDGE(vfork)
-    // __get_tls()[TLS_SLOT_THREAD_ID]->cached_pid_ = 0
+    // r3 = &__get_tls()[TLS_SLOT_THREAD_ID]
     mrc     p15, 0, r3, c13, c0, 3
     ldr     r3, [r3, #(TLS_SLOT_THREAD_ID * 4)]
-    mov     r0, #0
+
+    // Set cached_pid_ to 0, vforked_ to 1, and stash the previous value.
+    mov     r0, #0x80000000
+    ldr     r1, [r3, #12]
     str     r0, [r3, #12]
 
     mov     ip, r7
     ldr     r7, =__NR_vfork
     swi     #0
     mov     r7, ip
+
+    teq     r0, #0
+    bxeq    lr
+
+    // rc != 0: reset cached_pid_ and vforked_.
+    str     r1, [r3, #12]
     cmn     r0, #(MAX_ERRNO + 1)
+
     bxls    lr
     neg     r0, r0
     b       __set_errno_internal
diff --git a/libc/arch-arm64/bionic/vfork.S b/libc/arch-arm64/bionic/vfork.S
index a76e9ca39..5cfb8b0cc 100644
--- a/libc/arch-arm64/bionic/vfork.S
+++ b/libc/arch-arm64/bionic/vfork.S
@@ -36,10 +36,14 @@
 
 ENTRY(vfork)
 __BIONIC_WEAK_ASM_FOR_NATIVE_BRIDGE(vfork)
-    // __get_tls()[TLS_SLOT_THREAD_ID]->cached_pid_ = 0
-    mrs     x0, tpidr_el0
-    ldr     x0, [x0, #(TLS_SLOT_THREAD_ID * 8)]
-    str     wzr, [x0, #20]
+    // x9 = __get_tls()[TLS_SLOT_THREAD_ID]
+    mrs     x9, tpidr_el0
+    ldr     x9, [x9, #(TLS_SLOT_THREAD_ID * 8)]
+
+    // Set cached_pid_ to 0, vforked_ to 1, and stash the previous value.
+    mov     w0, #0x80000000
+    ldr     w10, [x9, #20]
+    str     w0, [x9, #20]
 
     mov     x0, #(CLONE_VM | CLONE_VFORK | SIGCHLD)
     mov     x1, xzr
@@ -50,6 +54,10 @@ __BIONIC_WEAK_ASM_FOR_NATIVE_BRIDGE(vfork)
     mov     x8, __NR_clone
     svc     #0
 
+    cbz     x0, .L_exit
+
+    // rc != 0: reset cached_pid_ and vforked_.
+    str     w10, [x9, #20]
     cmn     x0, #(MAX_ERRNO + 1)
     cneg    x0, x0, hi
     b.hi    __set_errno_internal
diff --git a/libc/arch-x86/bionic/vfork.S b/libc/arch-x86/bionic/vfork.S
index 663169c9b..231a36ec7 100644
--- a/libc/arch-x86/bionic/vfork.S
+++ b/libc/arch-x86/bionic/vfork.S
@@ -37,13 +37,25 @@ __BIONIC_WEAK_ASM_FOR_NATIVE_BRIDGE(vfork)
   .cfi_adjust_cfa_offset 4
   .cfi_rel_offset ecx, 0
 
-  // __get_tls()[TLS_SLOT_THREAD_ID]->cached_pid_ = 0
+  // Set cached_pid_ to 0, vforked_ to 1, and stash the previous value.
   movl    %gs:0, %eax
   movl    (TLS_SLOT_THREAD_ID * 4)(%eax), %eax
-  movl    $0, 12(%eax)
+  movl    12(%eax), %edx
+  movl    $0x80000000, 12(%eax)
 
   movl    $__NR_vfork, %eax
   int     $0x80
+
+  test    %eax, %eax
+  jz      1f
+
+  // rc != 0: restore the previous cached_pid_/vforked_ values.
+  pushl   %ecx
+  movl    %gs:0, %ecx
+  movl    (TLS_SLOT_THREAD_ID * 4)(%ecx), %ecx
+  movl    %edx, 12(%ecx)
+  popl    %ecx
+
   cmpl    $-MAX_ERRNO, %eax
   jb      1f
   negl    %eax
diff --git a/libc/arch-x86_64/bionic/vfork.S b/libc/arch-x86_64/bionic/vfork.S
index 86c5db2a1..8cfcc3658 100644
--- a/libc/arch-x86_64/bionic/vfork.S
+++ b/libc/arch-x86_64/bionic/vfork.S
@@ -35,14 +35,22 @@ ENTRY(vfork)
 __BIONIC_WEAK_ASM_FOR_NATIVE_BRIDGE(vfork)
   popq    %rdi  // Grab the return address.
 
-  // __get_tls()[TLS_SLOT_THREAD_ID]->cached_pid_ = 0
-  mov    %fs:0, %rax
-  mov    (TLS_SLOT_THREAD_ID * 8)(%rax), %rax
-  movl   $0, 20(%rax)
+  // Set cached_pid_ to 0, vforked_ to 1, and stash the previous value.
+  mov     %fs:0, %r8
+  mov     (TLS_SLOT_THREAD_ID * 8)(%r8), %r8
+  movl    20(%r8), %r9d
+  movl    $0x80000000, 20(%r8)
 
   movl    $__NR_vfork, %eax
   syscall
   pushq   %rdi  // Restore the return address.
+
+  test    %eax, %eax
+  jz      1f
+
+  // rc != 0: restore the previous cached_pid_/vforked_ values.
+  movl    %r9d, 20(%r8)
+
   cmpq    $-MAX_ERRNO, %rax
   jb      1f
   negl    %eax
diff --git a/libc/bionic/fdsan.cpp b/libc/bionic/fdsan.cpp
index ebc680f3e..4b8991872 100644
--- a/libc/bionic/fdsan.cpp
+++ b/libc/bionic/fdsan.cpp
@@ -246,6 +246,10 @@ uint64_t android_fdsan_get_tag_value(uint64_t tag) {
 }
 
 int android_fdsan_close_with_tag(int fd, uint64_t expected_tag) {
+  if (__get_thread()->is_vforked()) {
+    return __close(fd);
+  }
+
   FDTRACK_CLOSE(fd);
   FdEntry* fde = GetFdEntry(fd);
   if (!fde) {
@@ -296,6 +300,10 @@ uint64_t android_fdsan_get_owner_tag(int fd) {
 }
 
 void android_fdsan_exchange_owner_tag(int fd, uint64_t expected_tag, uint64_t new_tag) {
+  if (__get_thread()->is_vforked()) {
+    return;
+  }
+
   FdEntry* fde = GetFdEntry(fd);
   if (!fde) {
     return;
@@ -332,6 +340,10 @@ android_fdsan_error_level android_fdsan_get_error_level() {
 }
 
 android_fdsan_error_level android_fdsan_set_error_level(android_fdsan_error_level new_level) {
+  if (__get_thread()->is_vforked()) {
+    return android_fdsan_get_error_level();
+  }
+
   return atomic_exchange(&GetFdTable().error_level, new_level);
 }
 
diff --git a/libc/bionic/pthread_internal.h b/libc/bionic/pthread_internal.h
index ab8b9556d..1f055f59e 100644
--- a/libc/bionic/pthread_internal.h
+++ b/libc/bionic/pthread_internal.h
@@ -70,9 +70,12 @@ class pthread_internal_t {
   pid_t tid;
 
  private:
-  pid_t cached_pid_;
+  uint32_t cached_pid_ : 31;
+  uint32_t vforked_ : 1;
 
  public:
+  bool is_vforked() { return vforked_; }
+
   pid_t invalidate_cached_pid() {
     pid_t old_value;
     get_cached_pid(&old_value);
diff --git a/libc/private/bionic_fdtrack.h b/libc/private/bionic_fdtrack.h
index 174ba1d9b..752dd8dc5 100644
--- a/libc/private/bionic_fdtrack.h
+++ b/libc/private/bionic_fdtrack.h
@@ -47,7 +47,8 @@ extern "C" _Atomic(android_fdtrack_hook_t) __android_fdtrack_hook;
 #define FDTRACK_CREATE_NAME(name, fd_value)                       \
   ({                                                              \
     int __fd = (fd_value);                                        \
-    if (__fd != -1 && __predict_false(__android_fdtrack_hook)) {  \
+    if (__fd != -1 && __predict_false(__android_fdtrack_hook) &&  \
+        !__predict_false(__get_thread()->is_vforked())) {         \
       bionic_tls& tls = __get_bionic_tls();                       \
       /* fdtrack_disabled is only true during reentrant calls. */ \
       if (!__predict_false(tls.fdtrack_disabled)) {               \
@@ -76,7 +77,8 @@ extern "C" _Atomic(android_fdtrack_hook_t) __android_fdtrack_hook;
 #define FDTRACK_CLOSE(fd_value)                                  \
   ({                                                             \
     int __fd = (fd_value);                                       \
-    if (__fd != -1 && __predict_false(__android_fdtrack_hook)) { \
+    if (__fd != -1 && __predict_false(__android_fdtrack_hook) && \
+        !__predict_false(__get_thread()->is_vforked())) {        \
       bionic_tls& tls = __get_bionic_tls();                      \
       if (!__predict_false(tls.fdtrack_disabled)) {              \
         int saved_errno = errno;                                 \