[PATCH] add process_session() helper routine

From: Cedric Le Goater
Date: Tue Oct 17 2006 - 04:38:12 EST


This patch replaces occurences of task->signal->session by a new
process_session() helper routine.

It will be useful for pid namespaces to abstract the session pid
number.

Signed-off-by: Cedric Le Goater <clg@xxxxxxxxxx>
Cc: Kirill Korotaev <dev@xxxxxxxxxx>
Cc: Eric W. Biederman <ebiederm@xxxxxxxxxxxx>
Cc: Herbert Poetzl <herbert@xxxxxxxxxxxx>
Cc: Sukadev Bhattiprolu <sukadev@xxxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxx>
---
arch/mips/kernel/irixelf.c | 2 +-
drivers/char/mxser.c | 2 +-
drivers/char/rocket.c | 2 +-
drivers/char/tty_io.c | 18 +++++++++---------
fs/binfmt_elf.c | 4 ++--
fs/binfmt_elf_fdpic.c | 4 ++--
include/linux/sched.h | 5 +++++
kernel/exit.c | 19 ++++++++++---------
kernel/fork.c | 4 ++--
kernel/signal.c | 2 +-
kernel/sys.c | 8 ++++----
11 files changed, 38 insertions(+), 32 deletions(-)

Index: 2.6.19-rc2/arch/mips/kernel/irixelf.c
===================================================================
--- 2.6.19-rc2.orig/arch/mips/kernel/irixelf.c
+++ 2.6.19-rc2/arch/mips/kernel/irixelf.c
@@ -1149,7 +1149,7 @@ static int irix_core_dump(long signr, st
psinfo.pr_pid = prstatus.pr_pid = current->pid;
psinfo.pr_ppid = prstatus.pr_ppid = current->parent->pid;
psinfo.pr_pgrp = prstatus.pr_pgrp = process_group(current);
- psinfo.pr_sid = prstatus.pr_sid = current->signal->session;
+ psinfo.pr_sid = prstatus.pr_sid = process_session(current);
if (current->pid == current->tgid) {
/*
* This is the record for the group leader. Add in the
Index: 2.6.19-rc2/drivers/char/mxser.c
===================================================================
--- 2.6.19-rc2.orig/drivers/char/mxser.c
+++ 2.6.19-rc2/drivers/char/mxser.c
@@ -993,7 +993,7 @@ static int mxser_open(struct tty_struct
mxser_change_speed(info, NULL);
}

- info->session = current->signal->session;
+ info->session = process_session(current);
info->pgrp = process_group(current);

/*
Index: 2.6.19-rc2/drivers/char/rocket.c
===================================================================
--- 2.6.19-rc2.orig/drivers/char/rocket.c
+++ 2.6.19-rc2/drivers/char/rocket.c
@@ -1017,7 +1017,7 @@ static int rp_open(struct tty_struct *tt
/*
* Info->count is now 1; so it's safe to sleep now.
*/
- info->session = current->signal->session;
+ info->session = process_session(current);
info->pgrp = process_group(current);

if ((info->flags & ROCKET_INITIALIZED) == 0) {
Index: 2.6.19-rc2/drivers/char/tty_io.c
===================================================================
--- 2.6.19-rc2.orig/drivers/char/tty_io.c
+++ 2.6.19-rc2/drivers/char/tty_io.c
@@ -1512,9 +1512,9 @@ void disassociate_ctty(int on_exit)

/* Now clear signal->tty under the lock */
read_lock(&tasklist_lock);
- do_each_task_pid(current->signal->session, PIDTYPE_SID, p) {
+ do_each_task_pid(process_session(current), PIDTYPE_SID, p) {
p->signal->tty = NULL;
- } while_each_task_pid(current->signal->session, PIDTYPE_SID, p);
+ } while_each_task_pid(process_session(current), PIDTYPE_SID, p);
read_unlock(&tasklist_lock);
mutex_unlock(&tty_mutex);
unlock_kernel();
@@ -2554,7 +2554,7 @@ got_driver:
current->signal->tty = tty;
task_unlock(current);
current->signal->tty_old_pgrp = 0;
- tty->session = current->signal->session;
+ tty->session = process_session(current);
tty->pgrp = process_group(current);
}
return 0;
@@ -2890,7 +2890,7 @@ static int tiocsctty(struct tty_struct *
struct task_struct *p;

if (current->signal->leader &&
- (current->signal->session == tty->session))
+ (process_session(current) == tty->session))
return 0;
/*
* The process must be a session leader and
@@ -2922,7 +2922,7 @@ static int tiocsctty(struct tty_struct *
task_unlock(current);
mutex_unlock(&tty_mutex);
current->signal->tty_old_pgrp = 0;
- tty->session = current->signal->session;
+ tty->session = process_session(current);
tty->pgrp = process_group(current);
return 0;
}
@@ -2973,13 +2973,13 @@ static int tiocspgrp(struct tty_struct *
return retval;
if (!current->signal->tty ||
(current->signal->tty != real_tty) ||
- (real_tty->session != current->signal->session))
+ (real_tty->session != process_session(current)))
return -ENOTTY;
if (get_user(pgrp, p))
return -EFAULT;
if (pgrp < 0)
return -EINVAL;
- if (session_of_pgrp(pgrp) != current->signal->session)
+ if (session_of_pgrp(pgrp) != process_session(current))
return -EPERM;
real_tty->pgrp = pgrp;
return 0;
@@ -3334,7 +3334,7 @@ static void __do_SAK(void *arg)
/* Kill the entire session */
do_each_task_pid(session, PIDTYPE_SID, p) {
printk(KERN_NOTICE "SAK: killed process %d"
- " (%s): p->signal->session==tty->session\n",
+ " (%s): process_session(p)==tty->session\n",
p->pid, p->comm);
send_sig(SIGKILL, p, 1);
} while_each_task_pid(session, PIDTYPE_SID, p);
@@ -3344,7 +3344,7 @@ static void __do_SAK(void *arg)
do_each_thread(g, p) {
if (p->signal->tty == tty) {
printk(KERN_NOTICE "SAK: killed process %d"
- " (%s): p->signal->session==tty->session\n",
+ " (%s): process_session(p)==tty->session\n",
p->pid, p->comm);
send_sig(SIGKILL, p, 1);
continue;
Index: 2.6.19-rc2/fs/binfmt_elf.c
===================================================================
--- 2.6.19-rc2.orig/fs/binfmt_elf.c
+++ 2.6.19-rc2/fs/binfmt_elf.c
@@ -1313,7 +1313,7 @@ static void fill_prstatus(struct elf_prs
prstatus->pr_pid = p->pid;
prstatus->pr_ppid = p->parent->pid;
prstatus->pr_pgrp = process_group(p);
- prstatus->pr_sid = p->signal->session;
+ prstatus->pr_sid = process_session(p);
if (thread_group_leader(p)) {
/*
* This is the record for the group leader. Add in the
@@ -1359,7 +1359,7 @@ static int fill_psinfo(struct elf_prpsin
psinfo->pr_pid = p->pid;
psinfo->pr_ppid = p->parent->pid;
psinfo->pr_pgrp = process_group(p);
- psinfo->pr_sid = p->signal->session;
+ psinfo->pr_sid = process_session(p);

i = p->state ? ffz(~p->state) + 1 : 0;
psinfo->pr_state = i;
Index: 2.6.19-rc2/fs/binfmt_elf_fdpic.c
===================================================================
--- 2.6.19-rc2.orig/fs/binfmt_elf_fdpic.c
+++ 2.6.19-rc2/fs/binfmt_elf_fdpic.c
@@ -1325,7 +1325,7 @@ static void fill_prstatus(struct elf_prs
prstatus->pr_pid = p->pid;
prstatus->pr_ppid = p->parent->pid;
prstatus->pr_pgrp = process_group(p);
- prstatus->pr_sid = p->signal->session;
+ prstatus->pr_sid = process_session(p);
if (thread_group_leader(p)) {
/*
* This is the record for the group leader. Add in the
@@ -1374,7 +1374,7 @@ static int fill_psinfo(struct elf_prpsin
psinfo->pr_pid = p->pid;
psinfo->pr_ppid = p->parent->pid;
psinfo->pr_pgrp = process_group(p);
- psinfo->pr_sid = p->signal->session;
+ psinfo->pr_sid = process_session(p);

i = p->state ? ffz(~p->state) + 1 : 0;
psinfo->pr_state = i;
Index: 2.6.19-rc2/include/linux/sched.h
===================================================================
--- 2.6.19-rc2.orig/include/linux/sched.h
+++ 2.6.19-rc2/include/linux/sched.h
@@ -1031,6 +1031,11 @@ static inline pid_t process_group(struct
return tsk->signal->pgrp;
}

+static inline pid_t process_session(struct task_struct *tsk)
+{
+ return tsk->signal->session;
+}
+
static inline struct pid *task_pid(struct task_struct *task)
{
return task->pids[PIDTYPE_PID].pid;
Index: 2.6.19-rc2/kernel/exit.c
===================================================================
--- 2.6.19-rc2.orig/kernel/exit.c
+++ 2.6.19-rc2/kernel/exit.c
@@ -192,14 +192,14 @@ int session_of_pgrp(int pgrp)

read_lock(&tasklist_lock);
do_each_task_pid(pgrp, PIDTYPE_PGID, p) {
- if (p->signal->session > 0) {
- sid = p->signal->session;
+ if (process_session(p) > 0) {
+ sid = process_session(p);
goto out;
}
} while_each_task_pid(pgrp, PIDTYPE_PGID, p);
p = find_task_by_pid(pgrp);
if (p)
- sid = p->signal->session;
+ sid = process_session(p);
out:
read_unlock(&tasklist_lock);

@@ -224,8 +224,8 @@ static int will_become_orphaned_pgrp(int
|| p->exit_state
|| is_init(p->real_parent))
continue;
- if (process_group(p->real_parent) != pgrp
- && p->real_parent->signal->session == p->signal->session) {
+ if (process_group(p->real_parent) != pgrp &&
+ process_session(p->real_parent) == process_session(p)) {
ret = 0;
break;
}
@@ -301,7 +301,7 @@ void __set_special_pids(pid_t session, p
{
struct task_struct *curr = current->group_leader;

- if (curr->signal->session != session) {
+ if (process_session(curr) != session) {
detach_pid(curr, PIDTYPE_SID);
curr->signal->session = session;
attach_pid(curr, PIDTYPE_SID, session);
@@ -648,10 +648,11 @@ reparent_thread(struct task_struct *p, s
* outside, so the child pgrp is now orphaned.
*/
if ((process_group(p) != process_group(father)) &&
- (p->signal->session == father->signal->session)) {
+ (process_session(p) == process_session(father))) {
int pgrp = process_group(p);

- if (will_become_orphaned_pgrp(pgrp, NULL) && has_stopped_jobs(pgrp)) {
+ if (will_become_orphaned_pgrp(pgrp, NULL) &&
+ has_stopped_jobs(pgrp)) {
__kill_pg_info(SIGHUP, SEND_SIG_PRIV, pgrp);
__kill_pg_info(SIGCONT, SEND_SIG_PRIV, pgrp);
}
@@ -785,7 +786,7 @@ static void exit_notify(struct task_stru
t = tsk->real_parent;

if ((process_group(t) != process_group(tsk)) &&
- (t->signal->session == tsk->signal->session) &&
+ (process_session(t) == process_session(tsk)) &&
will_become_orphaned_pgrp(process_group(tsk), tsk) &&
has_stopped_jobs(process_group(tsk))) {
__kill_pg_info(SIGHUP, SEND_SIG_PRIV, process_group(tsk));
Index: 2.6.19-rc2/kernel/fork.c
===================================================================
--- 2.6.19-rc2.orig/kernel/fork.c
+++ 2.6.19-rc2/kernel/fork.c
@@ -1244,9 +1244,9 @@ static struct task_struct *copy_process(
if (thread_group_leader(p)) {
p->signal->tty = current->signal->tty;
p->signal->pgrp = process_group(current);
- p->signal->session = current->signal->session;
+ p->signal->session = process_session(current);
attach_pid(p, PIDTYPE_PGID, process_group(p));
- attach_pid(p, PIDTYPE_SID, p->signal->session);
+ attach_pid(p, PIDTYPE_SID, process_session(p));

list_add_tail_rcu(&p->tasks, &init_task.tasks);
__get_cpu_var(process_counts)++;
Index: 2.6.19-rc2/kernel/signal.c
===================================================================
--- 2.6.19-rc2.orig/kernel/signal.c
+++ 2.6.19-rc2/kernel/signal.c
@@ -575,7 +575,7 @@ static int check_kill_permission(int sig
error = -EPERM;
if ((info == SEND_SIG_NOINFO || (!is_si_special(info) && SI_FROMUSER(info)))
&& ((sig != SIGCONT) ||
- (current->signal->session != t->signal->session))
+ (process_session(current) != process_session(t)))
&& (current->euid ^ t->suid) && (current->euid ^ t->uid)
&& (current->uid ^ t->suid) && (current->uid ^ t->uid)
&& !capable(CAP_KILL))
Index: 2.6.19-rc2/kernel/sys.c
===================================================================
--- 2.6.19-rc2.orig/kernel/sys.c
+++ 2.6.19-rc2/kernel/sys.c
@@ -1381,7 +1381,7 @@ asmlinkage long sys_setpgid(pid_t pid, p

if (p->real_parent == group_leader) {
err = -EPERM;
- if (p->signal->session != group_leader->signal->session)
+ if (process_session(p) != process_session(group_leader))
goto out;
err = -EACCES;
if (p->did_exec)
@@ -1400,7 +1400,7 @@ asmlinkage long sys_setpgid(pid_t pid, p
struct task_struct *p;

do_each_task_pid(pgid, PIDTYPE_PGID, p) {
- if (p->signal->session == group_leader->signal->session)
+ if (process_session(p) == process_session(group_leader))
goto ok_pgid;
} while_each_task_pid(pgid, PIDTYPE_PGID, p);
goto out;
@@ -1459,7 +1459,7 @@ asmlinkage long sys_getpgrp(void)
asmlinkage long sys_getsid(pid_t pid)
{
if (!pid)
- return current->signal->session;
+ return process_session(current);
else {
int retval;
struct task_struct *p;
@@ -1471,7 +1471,7 @@ asmlinkage long sys_getsid(pid_t pid)
if (p) {
retval = security_task_getsid(p);
if (!retval)
- retval = p->signal->session;
+ retval = process_session(p);
}
read_unlock(&tasklist_lock);
return retval;
-
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