[PATCH 0/2] More cleanups in do_wait() pathes (V2)

[PATCH 0/2] More cleanups in do_wait() pathes (V2)

[Vitaly Mayatskikh]

Further cleanups of do_wait() and friends.

Vitaly Mayatskikh (2):
  Completely replace wait_noreap_copyout() by copy_wait_opts_to_user()
  Move more common code from wait_task_*() to copy_wait_opts_to_user()

 kernel/exit.c |   56 ++++++++++++++++++++------------------------------------
 1 files changed, 20 insertions(+), 36 deletions(-)

[PATCH 1/2] Completely replace wait_noreap_copyout() by copy_wait_opts_to_user()

[Vitaly Mayatskikh]

wait_noreap_copyout() currently is a short wrapper for
copy_wait_opts_to_user(), and wait_task_zombie() is the only one caller
of it.

Signed-off-by: Vitaly Mayatskikh <v.mayatskih@gmail.com>
---
 kernel/exit.c |   13 ++++---------
 1 files changed, 4 insertions(+), 9 deletions(-)

diff --git a/kernel/exit.c b/kernel/exit.c
index f22e82c..3952385 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -1143,14 +1143,6 @@ static int copy_wait_opts_to_user(struct wait_opts *wo, struct task_struct *p,
 		if (!retval)
 			retval = put_user(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)
-{
-	int retval = copy_wait_opts_to_user(wo, p, pid, uid, why, status, SIGCHLD);
-	put_task_struct(p);
 	if (!retval)
 		retval = pid;
 	return retval;
@@ -1184,7 +1176,10 @@ static int wait_task_zombie(struct wait_opts *wo, struct task_struct *p)
 			why = (exit_code & 0x80) ? CLD_DUMPED : CLD_KILLED;
 			status = exit_code & 0x7f;
 		}
-		return wait_noreap_copyout(wo, p, pid, uid, why, status);
+		retval = copy_wait_opts_to_user(wo, p, pid, uid,
+						why, status, SIGCHLD);
+		put_task_struct(p);
+		return retval;
 	}
 
 	/*
-- 
1.6.2.2

[PATCH 2/2] Move more common code from wait_task_*() to copy_wait_opts_to_user()

[Vitaly Mayatskikh]

Roland McGrath pointed me to more common checks and put_user() around
invoke of copy_wait_opts_to_user() in wait_task_*() functions.
This common code is moved to copy_wait_opts_to_user().

Signed-off-by: Vitaly Mayatskikh <v.mayatskih@gmail.com>
---
 kernel/exit.c |   45 +++++++++++++++++----------------------------
 1 files changed, 17 insertions(+), 28 deletions(-)

diff --git a/kernel/exit.c b/kernel/exit.c
index 3952385..1d42627 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -1124,7 +1124,8 @@ static int eligible_child(struct wait_opts *wo, struct task_struct *p)
 }
 
 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)
+				  pid_t pid, uid_t uid, int why, int status,
+				  int signal, int stat)
 {
 	struct siginfo __user *infop = wo->wo_info;
 	int retval = wo->wo_rusage
@@ -1143,6 +1144,8 @@ static int copy_wait_opts_to_user(struct wait_opts *wo, struct task_struct *p,
 		if (!retval)
 			retval = put_user(status, &infop->si_status);
 	}
+	if (!retval && wo->wo_stat)
+		retval = put_user(stat, wo->wo_stat);
 	if (!retval)
 		retval = pid;
 	return retval;
@@ -1157,7 +1160,7 @@ static int copy_wait_opts_to_user(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;
+	int retval, why, status, traced, stat;
 	pid_t pid = task_pid_vnr(p);
 	uid_t uid = __task_cred(p)->uid;
 
@@ -1177,7 +1180,7 @@ static int wait_task_zombie(struct wait_opts *wo, struct task_struct *p)
 			status = exit_code & 0x7f;
 		}
 		retval = copy_wait_opts_to_user(wo, p, pid, uid,
-						why, status, SIGCHLD);
+						why, status, SIGCHLD, 0);
 		put_task_struct(p);
 		return retval;
 	}
@@ -1260,23 +1263,18 @@ static int wait_task_zombie(struct wait_opts *wo, struct task_struct *p)
 	 */
 	read_unlock(&tasklist_lock);
 
-	status = (p->signal->flags & SIGNAL_GROUP_EXIT)
+	stat = (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);
 
-	if ((status & 0x7f) == 0) {
+	if ((stat & 0x7f) == 0) {
 		why = CLD_EXITED;
-		status >>= 8;
+		status = stat >> 8;
 	} else {
-		why = (status & 0x80) ? CLD_DUMPED : CLD_KILLED;
-		status &= 0x7f;
+		why = (stat & 0x80) ? CLD_DUMPED : CLD_KILLED;
+		status = stat & 0x7f;
 	}
 
-	retval = copy_wait_opts_to_user(wo, p, pid, uid, why, status, SIGCHLD);
-
-	if (!retval)
-		retval = pid;
+	retval = copy_wait_opts_to_user(wo, p, pid, uid, why, status, SIGCHLD, stat);
 
 	if (traced) {
 		write_lock_irq(&tasklist_lock);
@@ -1366,12 +1364,8 @@ unlock_sig:
 	why = ptrace ? CLD_TRAPPED : CLD_STOPPED;
 	read_unlock(&tasklist_lock);
 
-	retval = copy_wait_opts_to_user(wo, p, pid, uid, why, exit_code, SIGCHLD);
-
-	if (!retval && wo->wo_stat)
-		retval = put_user((exit_code << 8) | 0x7f, wo->wo_stat);
-	if (!retval)
-		retval = pid;
+	retval = copy_wait_opts_to_user(wo, p, pid, uid, why, exit_code, SIGCHLD,
+					(exit_code << 8) | 0x7f);
 	put_task_struct(p);
 
 	BUG_ON(!retval);
@@ -1411,15 +1405,10 @@ static int wait_task_continued(struct wait_opts *wo, struct task_struct *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, p, pid, uid, CLD_CONTINUED, SIGCONT,
+					SIGCHLD, 0xffff);
 	put_task_struct(p);
 
-	if (!retval && wo->wo_stat)
-		retval = put_user(0xffff, wo->wo_stat);
-	if (!retval)
-		retval = pid;
-
 	BUG_ON(retval == 0);
 
 	return retval;
@@ -1583,7 +1572,7 @@ 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);
+			retval = copy_wait_opts_to_user(wo, 0, 0, 0, 0, 0, 0, 0);
 		}
 	}
 	return retval;
-- 
1.6.2.2

Re: [PATCH 1/2] Completely replace wait_noreap_copyout() by copy_wait_opts_to_user()

[Roland McGrath]

This changes the return value of copy_wait_opts_to_user without changing
all its callers to match.


Thanks,
Roland

Re: [PATCH 1/2] Completely replace wait_noreap_copyout() by copy_wait_opts_to_user()

[Vitaly Mayatskikh]

At Thu, 14 May 2009 11:55:19 -0700 (PDT), Roland McGrath wrote:

> This changes the return value of copy_wait_opts_to_user without changing
> all its callers to match.

You're right, it was intended to go to the second patch. Damn... I
should be more attentive.

-- 
wbr, Vitaly