aboutsummaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorRichard Henderson <rth@redhat.com>2014-05-23 16:23:32 -0400
committerRichard Henderson <rth@redhat.com>2014-06-03 11:09:20 -0400
commit89b4bd6b6028852065b65b9d6cf4e1ea74a10634 (patch)
tree521b7ce4162917f4c247d04f6b628c5e84f7ceef
parent111cc714894d71fdc31c04e56b1bcd41b2680269 (diff)
downloadglibc-89b4bd6b6028852065b65b9d6cf4e1ea74a10634.tar
glibc-89b4bd6b6028852065b65b9d6cf4e1ea74a10634.tar.gz
glibc-89b4bd6b6028852065b65b9d6cf4e1ea74a10634.tar.bz2
glibc-89b4bd6b6028852065b65b9d6cf4e1ea74a10634.zip
aarch64: Consolidate NPTL/non versions of vfork
At the same time, incorporate the 0 -> 0x80000000 mapping of the pid expected by raise.c.
-rw-r--r--ChangeLog7
-rw-r--r--sysdeps/unix/sysv/linux/aarch64/nptl/pt-vfork.S35
-rw-r--r--sysdeps/unix/sysv/linux/aarch64/pt-vfork.c54
-rw-r--r--sysdeps/unix/sysv/linux/aarch64/vfork.S29
4 files changed, 81 insertions, 44 deletions
diff --git a/ChangeLog b/ChangeLog
index 2b30915f6d..8d40c8fd06 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,12 @@
2014-06-03 Richard Henderson <rth@redhat.com>
+ * sysdeps/unix/sysv/linux/aarch64/pt-vfork.c: New file.
+ * sysdeps/unix/sysv/linux/aarch64/nptl/pt-vfork.S: Remove file.
+ * sysdeps/unix/sysv/linux/aarch64/vfork.S (__vfork): Incorporate
+ SAVE_PID and RESTORE_PID blocks from pt-vfork.S. Map 0 to INT_MIN
+ in the SAVE_PID block.
+ (__libc_vfork): New alias.
+
* sysdeps/unix/sysv/linux/aarch64/clone.S (__clone): Save args for
child in registers, not on the stack. Remove RESET_PID conditionals.
* sysdeps/unix/sysv/linux/aarch64/nptl/clone.S: Remove file.
diff --git a/sysdeps/unix/sysv/linux/aarch64/nptl/pt-vfork.S b/sysdeps/unix/sysv/linux/aarch64/nptl/pt-vfork.S
deleted file mode 100644
index 2108347118..0000000000
--- a/sysdeps/unix/sysv/linux/aarch64/nptl/pt-vfork.S
+++ /dev/null
@@ -1,35 +0,0 @@
-/* Copyright (C) 2009-2014 Free Software Foundation, Inc.
-
- This file is part of the GNU C Library.
-
- The GNU C Library is free software; you can redistribute it and/or
- modify it under the terms of the GNU Lesser General Public License as
- published by the Free Software Foundation; either version 2.1 of the
- License, or (at your option) any later version.
-
- The GNU C Library is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- Lesser General Public License for more details.
-
- You should have received a copy of the GNU Lesser General Public
- License along with the GNU C Library; if not, see
- <http://www.gnu.org/licenses/>. */
-
-#include <tcb-offsets.h>
-
-/* Save the PID value. */
-#define SAVE_PID \
- mrs x2, tpidr_el0; \
- sub x2, x2, #PTHREAD_SIZEOF; \
- ldr w3, [x2, #PTHREAD_PID_OFFSET]; \
- neg w0, w3; \
- str w0, [x2, #PTHREAD_PID_OFFSET]
-
-/* Restore the old PID value in the parent. */
-#define RESTORE_PID \
- cbz x0, 1f; \
- str w3, [x2, #PTHREAD_PID_OFFSET]; \
-1:
-
-#include "../vfork.S"
diff --git a/sysdeps/unix/sysv/linux/aarch64/pt-vfork.c b/sysdeps/unix/sysv/linux/aarch64/pt-vfork.c
new file mode 100644
index 0000000000..5dd23bf00d
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/aarch64/pt-vfork.c
@@ -0,0 +1,54 @@
+/* vfork ABI-compatibility entry points for libpthread.
+ Copyright (C) 2014 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <http://www.gnu.org/licenses/>. */
+
+#include <shlib-compat.h>
+
+/* libpthread used to have its own vfork implementation that differed
+ from libc's only in having a pointless micro-optimization. There
+ is no longer any use to having a separate copy in libpthread, but
+ the historical ABI requires it. For static linking, there is no
+ need to provide anything here--the libc version will be linked in.
+ For shared library ABI compatibility, there must be __vfork and
+ vfork symbols in libpthread.so. */
+
+#if HAVE_IFUNC
+# include <nptl/pt-vfork.c>
+#elif (SHLIB_COMPAT (libpthread, GLIBC_2_0, GLIBC_2_20) \
+ || SHLIB_COMPAT (libpthread, GLIBC_2_1_2, GLIBC_2_20))
+
+/* Thankfully, on AArch64 we can rely on the compiler generating
+ a tail call here. */
+
+extern void __libc_vfork (void);
+
+void
+vfork_compat (void)
+{
+ __libc_vfork ();
+}
+
+# if SHLIB_COMPAT (libpthread, GLIBC_2_0, GLIBC_2_20)
+compat_symbol (libpthread, vfork_compat, vfork, GLIBC_2_0);
+# endif
+
+# if SHLIB_COMPAT (libpthread, GLIBC_2_1_2, GLIBC_2_20)
+strong_alias (vfork_compat, vfork_compat2)
+compat_symbol (libpthread, vfork_compat2, __vfork, GLIBC_2_1_2);
+# endif
+
+#endif
diff --git a/sysdeps/unix/sysv/linux/aarch64/vfork.S b/sysdeps/unix/sysv/linux/aarch64/vfork.S
index d9f2c70748..316cb65e9b 100644
--- a/sysdeps/unix/sysv/linux/aarch64/vfork.S
+++ b/sysdeps/unix/sysv/linux/aarch64/vfork.S
@@ -28,22 +28,33 @@
ENTRY (__vfork)
-#ifdef SAVE_PID
- SAVE_PID
-#endif
+ /* Save the TCB-cached PID away in w3, and then negate the TCB
+ field. But if it's zero, set it to 0x80000000 instead. See
+ raise.c for the logic that relies on this value. */
+ mrs x2, tpidr_el0
+ sub x2, x2, #PTHREAD_SIZEOF
+ ldr w3, [x2, #PTHREAD_PID_OFFSET]
+ mov w1, #0x80000000
+ negs w0, w3
+ csel w0, w1, w0, eq
+ str w0, [x2, #PTHREAD_PID_OFFSET]
+
mov x0, #0x4111 /* CLONE_VM | CLONE_VFORK | SIGCHLD */
mov x1, sp
DO_CALL (clone, 2)
-#ifdef RESTORE_PID
- RESTORE_PID
-#endif
+
+ /* Restore the original value of the TCB cache of the PID, if we're
+ the parent. But in the child (syscall return value equals zero),
+ leave things as they are. */
+ cbz x0, 1f
+ str w3, [x2, #PTHREAD_PID_OFFSET]
+1:
cmn x0, #4095
- b.cs 1f
+ b.cs .Lsyscall_error
RET
-1:
- b SYSCALL_ERROR
PSEUDO_END (__vfork)
libc_hidden_def (__vfork)
weak_alias (__vfork, vfork)
+strong_alias (__vfork, __libc_vfork)