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[Qemu-devel] [PATCH 1/2] linux-user: Remove unnecessary nptl_flags varia
From: |
Peter Maydell |
Subject: |
[Qemu-devel] [PATCH 1/2] linux-user: Remove unnecessary nptl_flags variable from do_fork() |
Date: |
Tue, 2 Aug 2016 18:41:26 +0100 |
The 'nptl_flags' variable in do_fork() is set to a copy of
'flags', and then the CLONE_NPTL_FLAGS are cleared out of 'flags'.
However the only effect of this is that the later check on
"if (flags & CLONE_PARENT_SETTID)" is never true. Since we
will already have done the setting of parent_tidptr in clone_func()
in the child thread, we don't need to do it again.
Delete the dead if() and the clearing of CLONE_NPTL_FLAGS from
'flags', and then use 'flags' where we were previously using
'nptl_flags', so we can delete the unnecessary variable.
Signed-off-by: Peter Maydell <address@hidden>
---
linux-user/syscall.c | 16 +++++++---------
1 file changed, 7 insertions(+), 9 deletions(-)
diff --git a/linux-user/syscall.c b/linux-user/syscall.c
index 17ecd10..1bde131 100644
--- a/linux-user/syscall.c
+++ b/linux-user/syscall.c
@@ -5856,7 +5856,6 @@ static int do_fork(CPUArchState *env, unsigned int flags,
abi_ulong newsp,
TaskState *ts;
CPUState *new_cpu;
CPUArchState *new_env;
- unsigned int nptl_flags;
sigset_t sigmask;
/* Emulate vfork() with fork() */
@@ -5879,15 +5878,14 @@ static int do_fork(CPUArchState *env, unsigned int
flags, abi_ulong newsp,
ts->bprm = parent_ts->bprm;
ts->info = parent_ts->info;
ts->signal_mask = parent_ts->signal_mask;
- nptl_flags = flags;
- flags &= ~CLONE_NPTL_FLAGS2;
- if (nptl_flags & CLONE_CHILD_CLEARTID) {
+ if (flags & CLONE_CHILD_CLEARTID) {
ts->child_tidptr = child_tidptr;
}
- if (nptl_flags & CLONE_SETTLS)
+ if (flags & CLONE_SETTLS) {
cpu_set_tls (new_env, newtls);
+ }
/* Grab a mutex so that thread setup appears atomic. */
pthread_mutex_lock(&clone_lock);
@@ -5897,10 +5895,12 @@ static int do_fork(CPUArchState *env, unsigned int
flags, abi_ulong newsp,
pthread_mutex_lock(&info.mutex);
pthread_cond_init(&info.cond, NULL);
info.env = new_env;
- if (nptl_flags & CLONE_CHILD_SETTID)
+ if (flags & CLONE_CHILD_SETTID) {
info.child_tidptr = child_tidptr;
- if (nptl_flags & CLONE_PARENT_SETTID)
+ }
+ if (flags & CLONE_PARENT_SETTID) {
info.parent_tidptr = parent_tidptr;
+ }
ret = pthread_attr_init(&attr);
ret = pthread_attr_setstacksize(&attr, NEW_STACK_SIZE);
@@ -5919,8 +5919,6 @@ static int do_fork(CPUArchState *env, unsigned int flags,
abi_ulong newsp,
/* Wait for the child to initialize. */
pthread_cond_wait(&info.cond, &info.mutex);
ret = info.tid;
- if (flags & CLONE_PARENT_SETTID)
- put_user_u32(ret, parent_tidptr);
} else {
ret = -1;
}
--
1.9.1