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Message-Id: <1242216490-8226-2-git-send-email-v.mayatskih@gmail.com>
Date: Wed, 13 May 2009 14:08:11 +0200
From: Vitaly Mayatskikh <v.mayatskih@...il.com>
To: Andrew Morton <akpm@...ux-foundation.org>
Cc: Oleg Nesterov <oleg@...hat.com>, Ingo Molnar <mingo@...e.hu>,
Roland McGrath <roland@...hat.com>,
linux-kernel@...r.kernel.org
Subject: [PATCH 1/3] Introduce "struct wait_info" to simplify wait_task*() pathes
There's too much parameters passing to wait_noreap_copyout() and
copy_wait_opts_to_user().
Introduce "struct wait_info" which holds data needed for user's siginfo
structure. This will save registers and some stack on
copy_wait_opts_to_user() invoke.
Signed-off-by: Vitaly Mayatskikh <v.mayatskih@...il.com>
---
kernel/exit.c | 116 +++++++++++++++++++++++++++++++--------------------------
1 files changed, 63 insertions(+), 53 deletions(-)
diff --git a/kernel/exit.c b/kernel/exit.c
index f22e82c..f069bc1 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -1088,6 +1088,15 @@ struct wait_opts {
int notask_error;
};
+struct wait_info {
+ struct task_struct* p;
+ pid_t pid;
+ uid_t uid;
+ int why;
+ int status;
+ int signal;
+};
+
static struct pid *task_pid_type(struct task_struct *task, enum pid_type type)
{
struct pid *pid = NULL;
@@ -1123,36 +1132,36 @@ static int eligible_child(struct wait_opts *wo, struct task_struct *p)
return 1;
}
-static int copy_wait_opts_to_user(struct wait_opts *wo, struct task_struct *p,
- pid_t pid, uid_t uid, int why, int status, int signal)
+static int copy_wait_opts_to_user(struct wait_opts *wo, struct wait_info *wi)
{
struct siginfo __user *infop = wo->wo_info;
int retval = wo->wo_rusage
- ? getrusage(p, RUSAGE_BOTH, wo->wo_rusage) : 0;
+ ? getrusage(wi->p, RUSAGE_BOTH, wo->wo_rusage) : 0;
if (!retval && infop) {
- retval = put_user(signal, &infop->si_signo);
+ retval = put_user(wi->signal, &infop->si_signo);
if (!retval)
retval = put_user(0, &infop->si_errno);
if (!retval)
- retval = put_user((short)why, &infop->si_code);
+ retval = put_user((short)wi->why, &infop->si_code);
if (!retval)
- retval = put_user(pid, &infop->si_pid);
+ retval = put_user(wi->pid, &infop->si_pid);
if (!retval)
- retval = put_user(uid, &infop->si_uid);
+ retval = put_user(wi->uid, &infop->si_uid);
if (!retval)
- retval = put_user(status, &infop->si_status);
+ retval = put_user(wi->status, &infop->si_status);
}
return retval;
}
-static int wait_noreap_copyout(struct wait_opts *wo, struct task_struct *p,
- pid_t pid, uid_t uid, int why, int status)
+static int wait_noreap_copyout(struct wait_opts *wo, struct wait_info *wi)
{
- int retval = copy_wait_opts_to_user(wo, p, pid, uid, why, status, SIGCHLD);
- put_task_struct(p);
+ int retval;
+ wi->signal = SIGCHLD;
+ retval = copy_wait_opts_to_user(wo, wi);
+ put_task_struct(wi->p);
if (!retval)
- retval = pid;
+ retval = wi->pid;
return retval;
}
@@ -1165,26 +1174,27 @@ static int wait_noreap_copyout(struct wait_opts *wo, struct task_struct *p,
static int wait_task_zombie(struct wait_opts *wo, struct task_struct *p)
{
unsigned long state;
- int retval, why, status, traced;
- pid_t pid = task_pid_vnr(p);
- uid_t uid = __task_cred(p)->uid;
+ int retval, traced;
+ struct wait_info wi = { .p = p, .pid = task_pid_vnr(p),
+ .uid = __task_cred(p)->uid,
+ .signal = SIGCHLD };
if (!likely(wo->wo_flags & WEXITED))
return 0;
if (unlikely(wo->wo_flags & WNOWAIT)) {
- int exit_code = p->exit_code;
+ wi.status = p->exit_code;
get_task_struct(p);
read_unlock(&tasklist_lock);
- if ((exit_code & 0x7f) == 0) {
- why = CLD_EXITED;
- status = exit_code >> 8;
+ if ((wi.status & 0x7f) == 0) {
+ wi.why = CLD_EXITED;
+ wi.status >>= 8;
} else {
- why = (exit_code & 0x80) ? CLD_DUMPED : CLD_KILLED;
- status = exit_code & 0x7f;
+ wi.why = (wi.status & 0x80) ? CLD_DUMPED : CLD_KILLED;
+ wi.status &= 0x7f;
}
- return wait_noreap_copyout(wo, p, pid, uid, why, status);
+ return wait_noreap_copyout(wo, &wi);
}
/*
@@ -1265,23 +1275,23 @@ static int wait_task_zombie(struct wait_opts *wo, struct task_struct *p)
*/
read_unlock(&tasklist_lock);
- status = (p->signal->flags & SIGNAL_GROUP_EXIT)
+ wi.status = (p->signal->flags & SIGNAL_GROUP_EXIT)
? p->signal->group_exit_code : p->exit_code;
if (wo->wo_stat)
- retval = put_user(status, wo->wo_stat);
+ retval = put_user(wi.status, wo->wo_stat);
- if ((status & 0x7f) == 0) {
- why = CLD_EXITED;
- status >>= 8;
+ if ((wi.status & 0x7f) == 0) {
+ wi.why = CLD_EXITED;
+ wi.status >>= 8;
} else {
- why = (status & 0x80) ? CLD_DUMPED : CLD_KILLED;
- status &= 0x7f;
+ wi.why = (wi.status & 0x80) ? CLD_DUMPED : CLD_KILLED;
+ wi.status &= 0x7f;
}
- retval = copy_wait_opts_to_user(wo, p, pid, uid, why, status, SIGCHLD);
+ retval = copy_wait_opts_to_user(wo, &wi);
if (!retval)
- retval = pid;
+ retval = wi.pid;
if (traced) {
write_lock_irq(&tasklist_lock);
@@ -1328,9 +1338,8 @@ static int *task_stopped_code(struct task_struct *p, bool ptrace)
static int wait_task_stopped(struct wait_opts *wo,
int ptrace, struct task_struct *p)
{
- int retval, exit_code, *p_code, why;
- uid_t uid = 0; /* unneeded, required by compiler */
- pid_t pid;
+ int retval, *p_code;
+ struct wait_info wi = { .p = p, .signal = SIGCHLD };
/*
* Traditionally we see ptrace'd stopped tasks regardless of options.
@@ -1338,25 +1347,25 @@ static int wait_task_stopped(struct wait_opts *wo,
if (!ptrace && !(wo->wo_flags & WUNTRACED))
return 0;
- exit_code = 0;
+ wi.status = 0;
spin_lock_irq(&p->sighand->siglock);
p_code = task_stopped_code(p, ptrace);
if (unlikely(!p_code))
goto unlock_sig;
- exit_code = *p_code;
- if (!exit_code)
+ wi.status = *p_code;
+ if (!wi.status)
goto unlock_sig;
if (!unlikely(wo->wo_flags & WNOWAIT))
*p_code = 0;
/* don't need the RCU readlock here as we're holding a spinlock */
- uid = __task_cred(p)->uid;
+ wi.uid = __task_cred(p)->uid;
unlock_sig:
spin_unlock_irq(&p->sighand->siglock);
- if (!exit_code)
+ if (!wi.status)
return 0;
/*
@@ -1367,16 +1376,16 @@ unlock_sig:
* possibly take page faults for user memory.
*/
get_task_struct(p);
- pid = task_pid_vnr(p);
- why = ptrace ? CLD_TRAPPED : CLD_STOPPED;
+ wi.pid = task_pid_vnr(p);
+ wi.why = ptrace ? CLD_TRAPPED : CLD_STOPPED;
read_unlock(&tasklist_lock);
- retval = copy_wait_opts_to_user(wo, p, pid, uid, why, exit_code, SIGCHLD);
+ retval = copy_wait_opts_to_user(wo, &wi);
if (!retval && wo->wo_stat)
- retval = put_user((exit_code << 8) | 0x7f, wo->wo_stat);
+ retval = put_user((wi.status << 8) | 0x7f, wo->wo_stat);
if (!retval)
- retval = pid;
+ retval = wi.pid;
put_task_struct(p);
BUG_ON(!retval);
@@ -1392,8 +1401,8 @@ unlock_sig:
static int wait_task_continued(struct wait_opts *wo, struct task_struct *p)
{
int retval;
- pid_t pid;
- uid_t uid;
+ struct wait_info wi = { .p = p, .why = CLD_CONTINUED,
+ .status = SIGCONT, .signal = SIGCHLD };
if (!unlikely(wo->wo_flags & WCONTINUED))
return 0;
@@ -1409,21 +1418,21 @@ static int wait_task_continued(struct wait_opts *wo, struct task_struct *p)
}
if (!unlikely(wo->wo_flags & WNOWAIT))
p->signal->flags &= ~SIGNAL_STOP_CONTINUED;
- uid = __task_cred(p)->uid;
+ wi.uid = __task_cred(p)->uid;
spin_unlock_irq(&p->sighand->siglock);
- pid = task_pid_vnr(p);
+ wi.pid = task_pid_vnr(p);
get_task_struct(p);
read_unlock(&tasklist_lock);
- retval = copy_wait_opts_to_user(wo, p, pid, uid,
- CLD_CONTINUED, SIGCONT, SIGCHLD);
+ retval = copy_wait_opts_to_user(wo, &wi);
+
put_task_struct(p);
if (!retval && wo->wo_stat)
retval = put_user(0xffff, wo->wo_stat);
if (!retval)
- retval = pid;
+ retval = wi.pid;
BUG_ON(retval == 0);
@@ -1588,7 +1597,8 @@ end:
* we would set so the user can easily tell the
* difference.
*/
- retval = copy_wait_opts_to_user(wo, 0, 0, 0, 0, 0, 0);
+ struct wait_info wi = { 0 };
+ retval = copy_wait_opts_to_user(wo, &wi);
}
}
return retval;
--
1.6.2.2
--
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