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Clean up forking and cloning.

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The kernel now maintains the pthread_internal_t::tid field for us,
and __clone was only used in one place so let's inline it so we don't
have to leave such a dangerous function lying around. Also rename
files to match their content and remove some useless #includes.

Change-Id: I24299fb4a940e394de75f864ee36fdabbd9438f9
This commit is contained in:
Elliott Hughes
2013-11-19 13:31:58 -08:00
parent 318e86ed88
commit 36d6188f8c
26 changed files with 44 additions and 172 deletions
Download Patch File Download Diff File Expand all files Collapse all files

2
libc/Android.mk
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@@ -77,7 +77,6 @@ libc_common_src_files := \
bionic/atol.c \
bionic/atoll.c \
bionic/bindresvport.c \
bionic/bionic_clone.c \
bionic/clearenv.c \
bionic/daemon.c \
bionic/err.c \
@@ -207,6 +206,7 @@ libc_bionic_src_files := \
bionic/brk.cpp \
bionic/chmod.cpp \
bionic/chown.cpp \
bionic/clone.cpp \
bionic/dirent.cpp \
bionic/dup2.cpp \
bionic/epoll_create.cpp \

5
libc/SYSCALLS.TXT
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@@ -275,9 +275,6 @@ int sysinfo(struct sysinfo*) all
int personality(unsigned long) all
long perf_event_open(struct perf_event_attr* attr_uptr, pid_t pid, int cpu, int group_fd, unsigned long flags) all
pid_t __clone:clone(int, void*, int*, void*, int*) all
int __set_tid_address:set_tid_address(int*) all
int epoll_create1(int) all
int epoll_ctl(int, int op, int, struct epoll_event*) all
int __epoll_pwait:epoll_pwait(int, struct epoll_event*, int, int, const sigset_t*, size_t) all
@@ -296,6 +293,8 @@ int inotify_rm_watch(int, unsigned int) all
int __pselect6:pselect6(int, fd_set*, fd_set*, fd_set*, timespec*, void*) all
int __ppoll:ppoll(pollfd*, unsigned int, timespec*, const sigset_t*, size_t) all
int __set_tid_address:set_tid_address(int*) all
pid_t wait4(pid_t, int*, int, struct rusage*) all
int __waitid:waitid(int, pid_t, struct siginfo_t*, int, void*) all

1
libc/arch-aarch64/syscalls.mk
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@@ -1,7 +1,6 @@
# Generated by gensyscalls.py. Do not edit.
syscall_src :=
syscall_src += arch-aarch64/syscalls/__brk.S
syscall_src += arch-aarch64/syscalls/__clone.S
syscall_src += arch-aarch64/syscalls/__epoll_pwait.S
syscall_src += arch-aarch64/syscalls/__exit.S
syscall_src += arch-aarch64/syscalls/__getcpu.S

22
libc/arch-aarch64/syscalls/__clone.S
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@@ -1,22 +0,0 @@
/* Generated by gensyscalls.py. Do not edit. */
#include <private/bionic_asm.h>
ENTRY(__clone)
stp x29, x30, [sp, #-16]!
mov x29, sp
str x8, [sp, #-16]!
mov x8, __NR_clone
svc #0
ldr x8, [sp], #16
ldp x29, x30, [sp], #16
cmn x0, #(MAX_ERRNO + 1)
cneg x0, x0, hi
b.hi __set_errno
ret
END(__clone)
.hidden _C_LABEL(__clone)

2
libc/arch-arm/arm.mk
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@@ -1,7 +1,7 @@
_LIBC_ARCH_COMMON_SRC_FILES := \
arch-arm/bionic/abort_arm.S \
arch-arm/bionic/atomics_arm.c \
arch-arm/bionic/clone.S \
arch-arm/bionic/__bionic_clone.S \
arch-arm/bionic/eabi.c \
arch-arm/bionic/_exit_with_stack_teardown.S \
arch-arm/bionic/futex_arm.S \

0
libc/arch-arm/bionic/clone.S → libc/arch-arm/bionic/__bionic_clone.S
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1
libc/arch-arm/syscalls.mk
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@@ -1,7 +1,6 @@
# Generated by gensyscalls.py. Do not edit.
syscall_src :=
syscall_src += arch-arm/syscalls/__brk.S
syscall_src += arch-arm/syscalls/__clone.S
syscall_src += arch-arm/syscalls/__epoll_pwait.S
syscall_src += arch-arm/syscalls/__exit.S
syscall_src += arch-arm/syscalls/__fcntl64.S

17
libc/arch-arm/syscalls/__clone.S
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@@ -1,17 +0,0 @@
/* Generated by gensyscalls.py. Do not edit. */
#include <private/bionic_asm.h>
ENTRY(__clone)
mov ip, sp
.save {r4, r5, r6, r7}
stmfd sp!, {r4, r5, r6, r7}
ldmfd ip, {r4, r5, r6}
ldr r7, =__NR_clone
swi #0
ldmfd sp!, {r4, r5, r6, r7}
cmn r0, #(MAX_ERRNO + 1)
bxls lr
neg r0, r0
b __set_errno
END(__clone)

0
libc/arch-mips/bionic/clone.S → libc/arch-mips/bionic/__bionic_clone.S
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2
libc/arch-mips/mips.mk
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@@ -1,7 +1,7 @@
_LIBC_ARCH_COMMON_SRC_FILES := \
arch-mips/bionic/__bionic_clone.S \
arch-mips/bionic/bzero.S \
arch-mips/bionic/cacheflush.cpp \
arch-mips/bionic/clone.S \
arch-mips/bionic/_exit_with_stack_teardown.S \
arch-mips/bionic/futex_mips.S \
arch-mips/bionic/__get_sp.S \

1
libc/arch-mips/syscalls.mk
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@@ -1,7 +1,6 @@
# Generated by gensyscalls.py. Do not edit.
syscall_src :=
syscall_src += arch-mips/syscalls/__brk.S
syscall_src += arch-mips/syscalls/__clone.S
syscall_src += arch-mips/syscalls/__epoll_pwait.S
syscall_src += arch-mips/syscalls/__exit.S
syscall_src += arch-mips/syscalls/__fcntl64.S

23
libc/arch-mips/syscalls/__clone.S
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@@ -1,23 +0,0 @@
/* Generated by gensyscalls.py. Do not edit. */
#include <asm/unistd.h>
.text
.globl __clone
.align 4
.ent __clone
__clone:
.set noreorder
.cpload $t9
li $v0, __NR_clone
syscall
bnez $a3, 1f
move $a0, $v0
j $ra
nop
1:
la $t9,__set_errno
j $t9
nop
.set reorder
.end __clone

0
libc/arch-x86/bionic/clone.S → libc/arch-x86/bionic/__bionic_clone.S
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1
libc/arch-x86/syscalls.mk
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@@ -1,7 +1,6 @@
# Generated by gensyscalls.py. Do not edit.
syscall_src :=
syscall_src += arch-x86/syscalls/__brk.S
syscall_src += arch-x86/syscalls/__clone.S
syscall_src += arch-x86/syscalls/__epoll_pwait.S
syscall_src += arch-x86/syscalls/__exit.S
syscall_src += arch-x86/syscalls/__fcntl64.S

32
libc/arch-x86/syscalls/__clone.S
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@@ -1,32 +0,0 @@
/* Generated by gensyscalls.py. Do not edit. */
#include <private/bionic_asm.h>
ENTRY(__clone)
pushl %ebx
pushl %ecx
pushl %edx
pushl %esi
pushl %edi
mov 24(%esp), %ebx
mov 28(%esp), %ecx
mov 32(%esp), %edx
mov 36(%esp), %esi
mov 40(%esp), %edi
movl $__NR_clone, %eax
int $0x80
cmpl $-MAX_ERRNO, %eax
jb 1f
negl %eax
pushl %eax
call __set_errno
addl $4, %esp
orl $-1, %eax
1:
popl %edi
popl %esi
popl %edx
popl %ecx
popl %ebx
ret
END(__clone)

2
libc/arch-x86/x86.mk
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@@ -1,5 +1,5 @@
_LIBC_ARCH_COMMON_SRC_FILES := \
arch-x86/bionic/clone.S \
arch-x86/bionic/__bionic_clone.S \
arch-x86/bionic/_exit_with_stack_teardown.S \
arch-x86/bionic/futex_x86.S \
arch-x86/bionic/__get_sp.S \

5
libc/arch-x86_64/bionic/clone.S → libc/arch-x86_64/bionic/__bionic_clone.S
View File

@@ -40,8 +40,13 @@ ENTRY(__bionic_clone)
movq %rax, -8(%rsi) # Write 'arg'.
subq $16, %rsi
# Translate to the kernel calling convention and swap the 'tls' and 'child_tid' arguments.
# They're flipped for x86-64 compared to all our other architectures and __bionic_clone.
movq %r8, %r10
movq %rcx, %r8
# Make the system call.
movl $__NR_clone, %eax
syscall
testl %eax, %eax

1
libc/arch-x86_64/syscalls.mk
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@@ -2,7 +2,6 @@
syscall_src :=
syscall_src += arch-x86_64/syscalls/__arch_prctl.S
syscall_src += arch-x86_64/syscalls/__brk.S
syscall_src += arch-x86_64/syscalls/__clone.S
syscall_src += arch-x86_64/syscalls/__epoll_pwait.S
syscall_src += arch-x86_64/syscalls/__exit.S
syscall_src += arch-x86_64/syscalls/__getcpu.S

18
libc/arch-x86_64/syscalls/__clone.S
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@@ -1,18 +0,0 @@
/* Generated by gensyscalls.py. Do not edit. */
#include <private/bionic_asm.h>
ENTRY(__clone)
movq %rcx, %r10
movl $__NR_clone, %eax
syscall
cmpq $-MAX_ERRNO, %rax
jb 1f
negl %eax
movl %eax, %edi
call __set_errno
orq $-1, %rax
1:
ret
END(__clone)
.hidden _C_LABEL(__clone)

2
libc/arch-x86_64/x86_64.mk
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@@ -1,5 +1,5 @@
_LIBC_ARCH_COMMON_SRC_FILES := \
arch-x86_64/bionic/clone.S \
arch-x86_64/bionic/__bionic_clone.S \
arch-x86_64/bionic/_exit_with_stack_teardown.S \
arch-x86_64/bionic/futex_x86_64.S \
arch-x86_64/bionic/__get_sp.S \

46
libc/bionic/bionic_clone.c → libc/bionic/clone.cpp
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@@ -25,41 +25,39 @@
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#define __GNU_SOURCE 1
#include <sched.h>
#include <stdlib.h>
#include <stdarg.h>
#include <stdio.h>
extern pid_t __bionic_clone(uint32_t flags, void* child_stack, int* parent_tid, void* tls, int* child_tid, int (*fn)(void*), void* arg);
extern void __exit(int status);
extern "C" pid_t __bionic_clone(uint32_t flags, void* child_stack, int* parent_tid, void* tls, int* child_tid, int (*fn)(void*), void* arg);
extern "C" void __exit(int status);
/* this function is called from the __bionic_clone
* assembly fragment to call the thread function
* then exit. */
extern void __bionic_clone_entry(int (*fn)(void*), void* arg) {
// Called from the __bionic_clone assembler to call the thread function then exit.
extern "C" void __bionic_clone_entry(int (*fn)(void*), void* arg) {
int status = (*fn)(arg);
__exit(status);
}
int clone(int (*fn)(void*), void* child_stack, int flags, void* arg, ...) {
va_list args;
int *parent_tidptr = NULL;
void *new_tls = NULL;
int *child_tidptr = NULL;
int* parent_tid = NULL;
void* new_tls = NULL;
int* child_tid = NULL;
/* extract optional parameters - they are cumulative. */
va_start(args, arg);
if (flags & (CLONE_PARENT_SETTID|CLONE_SETTLS|CLONE_CHILD_SETTID)) {
parent_tidptr = va_arg(args, int*);
}
if (flags & (CLONE_SETTLS|CLONE_CHILD_SETTID)) {
new_tls = va_arg(args, void*);
}
if (flags & CLONE_CHILD_SETTID) {
child_tidptr = va_arg(args, int*);
}
va_end(args);
// Extract any optional parameters required by the flags.
va_list args;
va_start(args, arg);
if ((flags & (CLONE_PARENT_SETTID|CLONE_SETTLS|CLONE_CHILD_SETTID|CLONE_CHILD_CLEARTID)) != 0) {
parent_tid = va_arg(args, int*);
}
if ((flags & (CLONE_SETTLS|CLONE_CHILD_SETTID|CLONE_CHILD_CLEARTID)) != 0) {
new_tls = va_arg(args, void*);
}
if ((flags & (CLONE_CHILD_SETTID|CLONE_CHILD_CLEARTID)) != 0) {
child_tid = va_arg(args, int*);
}
va_end(args);
return __bionic_clone(flags, child_stack, parent_tidptr, new_tls, child_tidptr, fn, arg);
return __bionic_clone(flags, child_stack, parent_tid, new_tls, child_tid, fn, arg);
}

22
libc/bionic/fork.cpp
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@@ -27,12 +27,11 @@
*/
#include <unistd.h>
#include <sys/syscall.h>
#include "private/libc_logging.h"
#include "pthread_internal.h"
#include "private/bionic_pthread.h"
extern "C" int __clone(int, void*, int*, void*, int*);
int fork() {
// POSIX mandates that the timers of a fork child process be
// disarmed, but not destroyed. To avoid a race condition, we're
@@ -42,18 +41,17 @@ int fork() {
__bionic_atfork_run_prepare();
pthread_internal_t* self = __get_thread();
#if defined(__x86_64__)
int result = __clone(CLONE_CHILD_SETTID | CLONE_CHILD_CLEARTID | SIGCHLD, NULL, NULL, &(self->tid), NULL);
int flags = CLONE_CHILD_SETTID | CLONE_CHILD_CLEARTID | SIGCHLD;
#if defined(__x86_64__) // sys_clone's last two arguments are flipped on x86-64.
int result = syscall(__NR_clone, flags, NULL, NULL, &(self->tid), NULL);
#else
int result = __clone(CLONE_CHILD_SETTID | CLONE_CHILD_CLEARTID | SIGCHLD, NULL, NULL, NULL, &(self->tid));
int result = syscall(__NR_clone, flags, NULL, NULL, NULL, &(self->tid));
#endif
if (result != 0) { // Not a child process.
if (result == 0) {
__bionic_atfork_run_child();
} else {
__timer_table_start_stop(0);
__bionic_atfork_run_parent();
} else {
// Fix the tid in the pthread_internal_t struct after a fork.
__pthread_settid(pthread_self(), gettid());
__bionic_atfork_run_child();
}
return result;
}

1
libc/bionic/pthread_cond.cpp
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@@ -38,7 +38,6 @@
#include "private/bionic_atomic_inline.h"
#include "private/bionic_futex.h"
#include "private/bionic_pthread.h"
#include "private/bionic_time_conversions.h"
#include "private/bionic_tls.h"
#include "private/thread_private.h"

1
libc/bionic/pthread_internal.h
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@@ -97,6 +97,5 @@ __LIBC_HIDDEN__ extern void __timer_table_start_stop(int);
__LIBC_HIDDEN__ extern void __bionic_atfork_run_prepare();
__LIBC_HIDDEN__ extern void __bionic_atfork_run_child();
__LIBC_HIDDEN__ extern void __bionic_atfork_run_parent();
__LIBC_HIDDEN__ extern int __pthread_settid(pthread_t, pid_t);
#endif /* _PTHREAD_INTERNAL_H_ */

8
libc/bionic/pthread_internals.cpp
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@@ -73,14 +73,6 @@ pid_t __pthread_gettid(pthread_t t) {
return reinterpret_cast<pthread_internal_t*>(t)->tid;
}
int __pthread_settid(pthread_t t, pid_t tid) {
if (t == 0) {
return EINVAL;
}
reinterpret_cast<pthread_internal_t*>(t)->tid = tid;
return 0;
}
// Initialize 'ts' with the difference between 'abstime' and the current time
// according to 'clock'. Returns -1 if abstime already expired, or 0 otherwise.
int __timespec_to_absolute(timespec* ts, const timespec* abstime, clockid_t clock) {

1
libc/bionic/pthread_mutex.cpp
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@@ -38,7 +38,6 @@
#include "private/bionic_atomic_inline.h"
#include "private/bionic_futex.h"
#include "private/bionic_pthread.h"
#include "private/bionic_tls.h"
#include "private/thread_private.h"