[PATCH] use group_leader->pgrp (was Re: setpgid and threads)

[PATCH] use group_leader->pgrp (was Re: setpgid and threads)

[Jeremy Fitzhardinge]

On Wed, 2003-08-20 at 19:49, Andrew Morton wrote:
> Using current->thread_group->foo sounds like a reasonable solution

Here's a patch to use group_leader->pgrp rather than just ->pgrp so that
all threads in a group appear to have the same process group ID.  This
is against 2.6.0-test4-mm6, and so it backs out the previous patch to
kernel/sys.c.

I'm running this now, and it seems to work, including the original test
with which I noticed the original problem.  I can't claim to have
heavily tested it though.  I think I've compiled all the affected code,
except the non-x86 arch-specific stuff.  The only mildly subtle stuff
seems to be in around the handling of execve() in kernel/pid.c.

	J

 arch/h8300/kernel/signal.c     |    2 +-
 arch/m68k/kernel/signal.c      |    2 +-
 arch/m68knommu/kernel/signal.c |    2 +-
 arch/mips/kernel/irixelf.c     |    2 +-
 arch/mips/kernel/irixsig.c     |    2 +-
 arch/mips/kernel/sysirix.c     |    4 ++--
 arch/sparc64/solaris/misc.c    |    4 ++--
 drivers/char/n_tty.c           |    6 +++---
 drivers/char/rocket.c          |    2 +-
 drivers/char/tty_io.c          |    2 +-
 fs/autofs/autofs_i.h           |    2 +-
 fs/autofs/inode.c              |    2 +-
 fs/autofs/root.c               |    4 ++--
 fs/autofs4/autofs_i.h          |    2 +-
 fs/autofs4/inode.c             |    4 ++--
 fs/autofs4/root.c              |    4 ++--
 fs/binfmt_elf.c                |    4 ++--
 fs/coda/upcall.c               |    2 +-
 fs/devfs/base.c                |    6 +++---
 fs/proc/array.c                |    2 +-
 kernel/exit.c                  |   20 ++++++++++----------
 kernel/pid.c                   |    2 +-
 kernel/signal.c                |    4 ++--
 kernel/sys.c                   |   21 +++++----------------
 24 files changed, 48 insertions(+), 59 deletions(-)

diff -puN arch/h8300/kernel/signal.c~pgrp arch/h8300/kernel/signal.c
--- local-2.6/arch/h8300/kernel/signal.c~pgrp	2003-09-08 18:19:32.000000000 -0700
+++ local-2.6-jeremy/arch/h8300/kernel/signal.c	2003-09-08 18:19:32.000000000 -0700
@@ -593,7 +593,7 @@ asmlinkage int do_signal(sigset_t *oldse
 				continue;
 
 			case SIGTSTP: case SIGTTIN: case SIGTTOU:
-				if (is_orphaned_pgrp(current->pgrp))
+				if (is_orphaned_pgrp(current->group_leader->pgrp))
 					continue;
 				/* FALLTHRU */
 
diff -puN arch/m68k/kernel/signal.c~pgrp arch/m68k/kernel/signal.c
--- local-2.6/arch/m68k/kernel/signal.c~pgrp	2003-09-08 18:19:32.000000000 -0700
+++ local-2.6-jeremy/arch/m68k/kernel/signal.c	2003-09-08 18:19:32.000000000 -0700
@@ -1082,7 +1082,7 @@ asmlinkage int do_signal(sigset_t *oldse
 				continue;
 
 			case SIGTSTP: case SIGTTIN: case SIGTTOU:
-				if (is_orphaned_pgrp(current->pgrp))
+				if (is_orphaned_pgrp(current->group_leader->pgrp))
 					continue;
 				/* FALLTHRU */
 
diff -puN arch/m68knommu/kernel/signal.c~pgrp arch/m68knommu/kernel/signal.c
--- local-2.6/arch/m68knommu/kernel/signal.c~pgrp	2003-09-08 18:19:32.000000000 -0700
+++ local-2.6-jeremy/arch/m68knommu/kernel/signal.c	2003-09-08 18:19:32.000000000 -0700
@@ -841,7 +841,7 @@ asmlinkage int do_signal(sigset_t *oldse
 				continue;
 
 			case SIGTSTP: case SIGTTIN: case SIGTTOU:
-				if (is_orphaned_pgrp(current->pgrp))
+				if (is_orphaned_pgrp(current->group_leader->pgrp))
 					continue;
 				/* FALLTHRU */
 
diff -puN arch/mips/kernel/irixelf.c~pgrp arch/mips/kernel/irixelf.c
--- local-2.6/arch/mips/kernel/irixelf.c~pgrp	2003-09-08 18:19:32.000000000 -0700
+++ local-2.6-jeremy/arch/mips/kernel/irixelf.c	2003-09-08 18:19:32.000000000 -0700
@@ -1129,7 +1129,7 @@ static int irix_core_dump(long signr, st
 	prstatus.pr_sighold = current->blocked.sig[0];
 	psinfo.pr_pid = prstatus.pr_pid = current->pid;
 	psinfo.pr_ppid = prstatus.pr_ppid = current->parent->pid;
-	psinfo.pr_pgrp = prstatus.pr_pgrp = current->pgrp;
+	psinfo.pr_pgrp = prstatus.pr_pgrp = current->group_leader->pgrp;
 	psinfo.pr_sid = prstatus.pr_sid = current->session;
 	prstatus.pr_utime.tv_sec = CT_TO_SECS(current->utime);
 	prstatus.pr_utime.tv_usec = CT_TO_USECS(current->utime);
diff -puN arch/mips/kernel/irixsig.c~pgrp arch/mips/kernel/irixsig.c
--- local-2.6/arch/mips/kernel/irixsig.c~pgrp	2003-09-08 18:19:32.000000000 -0700
+++ local-2.6-jeremy/arch/mips/kernel/irixsig.c	2003-09-08 18:19:32.000000000 -0700
@@ -582,7 +582,7 @@ repeat:
 		p = list_entry(_p,struct task_struct,sibling);
 		if ((type == P_PID) && p->pid != pid)
 			continue;
-		if ((type == P_PGID) && p->pgrp != pid)
+		if ((type == P_PGID) && p->group_leader->pgrp != pid)
 			continue;
 		if ((p->exit_signal != SIGCHLD))
 			continue;
diff -puN arch/mips/kernel/sysirix.c~pgrp arch/mips/kernel/sysirix.c
--- local-2.6/arch/mips/kernel/sysirix.c~pgrp	2003-09-08 18:19:32.000000000 -0700
+++ local-2.6-jeremy/arch/mips/kernel/sysirix.c	2003-09-08 18:19:32.000000000 -0700
@@ -803,11 +803,11 @@ asmlinkage int irix_setpgrp(int flags)
 	printk("[%s:%d] setpgrp(%d) ", current->comm, current->pid, flags);
 #endif
 	if(!flags)
-		error = current->pgrp;
+		error = current->group_leader->pgrp;
 	else
 		error = sys_setsid();
 #ifdef DEBUG_PROCGRPS
-	printk("returning %d\n", current->pgrp);
+	printk("returning %d\n", current->group_leader->pgrp);
 #endif
 
 	return error;
diff -puN arch/sparc64/solaris/misc.c~pgrp arch/sparc64/solaris/misc.c
--- local-2.6/arch/sparc64/solaris/misc.c~pgrp	2003-09-08 18:19:32.000000000 -0700
+++ local-2.6-jeremy/arch/sparc64/solaris/misc.c	2003-09-08 18:19:32.000000000 -0700
@@ -392,7 +392,7 @@ asmlinkage int solaris_procids(int cmd, 
 	
 	switch (cmd) {
 	case 0: /* getpgrp */
-		return current->pgrp;
+		return current->group_leader->pgrp;
 	case 1: /* setpgrp */
 		{
 			int (*sys_setpgid)(pid_t,pid_t) =
@@ -403,7 +403,7 @@ asmlinkage int solaris_procids(int cmd, 
 			ret = sys_setpgid(0, 0);
 			if (ret) return ret;
 			current->tty = NULL;
-			return current->pgrp;
+			return current->group_leader->pgrp;
 		}
 	case 2: /* getsid */
 		{
diff -puN drivers/char/n_tty.c~pgrp drivers/char/n_tty.c
--- local-2.6/drivers/char/n_tty.c~pgrp	2003-09-08 18:19:32.000000000 -0700
+++ local-2.6-jeremy/drivers/char/n_tty.c	2003-09-08 18:19:32.000000000 -0700
@@ -977,11 +977,11 @@ do_it_again:
 	if (file->f_op->write != redirected_tty_write && current->tty == tty) {
 		if (tty->pgrp <= 0)
 			printk("read_chan: tty->pgrp <= 0!\n");
-		else if (current->pgrp != tty->pgrp) {
+		else if (current->group_leader->pgrp != tty->pgrp) {
 			if (is_ignored(SIGTTIN) ||
-			    is_orphaned_pgrp(current->pgrp))
+			    is_orphaned_pgrp(current->group_leader->pgrp))
 				return -EIO;
-			kill_pg(current->pgrp, SIGTTIN, 1);
+			kill_pg(current->group_leader->pgrp, SIGTTIN, 1);
 			return -ERESTARTSYS;
 		}
 	}
diff -puN drivers/char/rocket.c~pgrp drivers/char/rocket.c
--- local-2.6/drivers/char/rocket.c~pgrp	2003-09-08 18:19:32.000000000 -0700
+++ local-2.6-jeremy/drivers/char/rocket.c	2003-09-08 18:19:32.000000000 -0700
@@ -956,7 +956,7 @@ static int rp_open(struct tty_struct *tt
 	 * Info->count is now 1; so it's safe to sleep now.
 	 */
 	info->session = current->session;
-	info->pgrp = current->pgrp;
+	info->pgrp = current->group_leader->pgrp;
 
 	if ((info->flags & ROCKET_INITIALIZED) == 0) {
 		cp = &info->channel;
diff -puN drivers/char/tty_io.c~pgrp drivers/char/tty_io.c
--- local-2.6/drivers/char/tty_io.c~pgrp	2003-09-08 18:19:32.000000000 -0700
+++ local-2.6-jeremy/drivers/char/tty_io.c	2003-09-08 18:19:32.000000000 -0700
@@ -325,7 +325,7 @@ int tty_check_change(struct tty_struct *
 		printk(KERN_WARNING "tty_check_change: tty->pgrp <= 0!\n");
 		return 0;
 	}
-	if (current->pgrp == tty->pgrp)
+	if (current->group_leader->pgrp == tty->pgrp)
 		return 0;
 	if (is_ignored(SIGTTOU))
 		return 0;
diff -puN fs/autofs/autofs_i.h~pgrp fs/autofs/autofs_i.h
--- local-2.6/fs/autofs/autofs_i.h~pgrp	2003-09-08 18:19:32.000000000 -0700
+++ local-2.6-jeremy/fs/autofs/autofs_i.h	2003-09-08 18:19:32.000000000 -0700
@@ -123,7 +123,7 @@ static inline struct autofs_sb_info *aut
    filesystem without "magic".) */
 
 static inline int autofs_oz_mode(struct autofs_sb_info *sbi) {
-	return sbi->catatonic || current->pgrp == sbi->oz_pgrp;
+	return sbi->catatonic || current->group_leader->pgrp == sbi->oz_pgrp;
 }
 
 /* Hash operations */
diff -puN fs/autofs/inode.c~pgrp fs/autofs/inode.c
--- local-2.6/fs/autofs/inode.c~pgrp	2003-09-08 18:19:32.000000000 -0700
+++ local-2.6-jeremy/fs/autofs/inode.c	2003-09-08 18:19:32.000000000 -0700
@@ -51,7 +51,7 @@ static int parse_options(char *options, 
 	
 	*uid = current->uid;
 	*gid = current->gid;
-	*pgrp = current->pgrp;
+	*pgrp = current->group_leader->pgrp;
 
 	*minproto = *maxproto = AUTOFS_PROTO_VERSION;
 
diff -puN fs/autofs/root.c~pgrp fs/autofs/root.c
--- local-2.6/fs/autofs/root.c~pgrp	2003-09-08 18:19:32.000000000 -0700
+++ local-2.6-jeremy/fs/autofs/root.c	2003-09-08 18:19:32.000000000 -0700
@@ -213,7 +213,7 @@ static struct dentry *autofs_root_lookup
 
 	oz_mode = autofs_oz_mode(sbi);
 	DPRINTK(("autofs_lookup: pid = %u, pgrp = %u, catatonic = %d, oz_mode = %d\n",
-		 current->pid, current->pgrp, sbi->catatonic, oz_mode));
+		 current->pid, current->group_leader->pgrp, sbi->catatonic, oz_mode));
 
 	/*
 	 * Mark the dentry incomplete, but add it. This is needed so
@@ -527,7 +527,7 @@ static int autofs_root_ioctl(struct inod
 {
 	struct autofs_sb_info *sbi = autofs_sbi(inode->i_sb);
 
-	DPRINTK(("autofs_ioctl: cmd = 0x%08x, arg = 0x%08lx, sbi = %p, pgrp = %u\n",cmd,arg,sbi,current->pgrp));
+	DPRINTK(("autofs_ioctl: cmd = 0x%08x, arg = 0x%08lx, sbi = %p, pgrp = %u\n",cmd,arg,sbi,current->group_leader->pgrp));
 
 	if ( _IOC_TYPE(cmd) != _IOC_TYPE(AUTOFS_IOC_FIRST) ||
 	     _IOC_NR(cmd) - _IOC_NR(AUTOFS_IOC_FIRST) >= AUTOFS_IOC_COUNT )
diff -puN fs/autofs4/autofs_i.h~pgrp fs/autofs4/autofs_i.h
--- local-2.6/fs/autofs4/autofs_i.h~pgrp	2003-09-08 18:19:32.000000000 -0700
+++ local-2.6-jeremy/fs/autofs4/autofs_i.h	2003-09-08 18:19:32.000000000 -0700
@@ -113,7 +113,7 @@ static inline struct autofs_info *autofs
    filesystem without "magic".) */
 
 static inline int autofs4_oz_mode(struct autofs_sb_info *sbi) {
-	return sbi->catatonic || current->pgrp == sbi->oz_pgrp;
+	return sbi->catatonic || current->group_leader->pgrp == sbi->oz_pgrp;
 }
 
 /* Does a dentry have some pending activity? */
diff -puN fs/autofs4/inode.c~pgrp fs/autofs4/inode.c
--- local-2.6/fs/autofs4/inode.c~pgrp	2003-09-08 18:19:32.000000000 -0700
+++ local-2.6-jeremy/fs/autofs4/inode.c	2003-09-08 18:19:32.000000000 -0700
@@ -101,7 +101,7 @@ static int parse_options(char *options, 
 	
 	*uid = current->uid;
 	*gid = current->gid;
-	*pgrp = current->pgrp;
+	*pgrp = current->group_leader->pgrp;
 
 	*minproto = AUTOFS_MIN_PROTO_VERSION;
 	*maxproto = AUTOFS_MAX_PROTO_VERSION;
@@ -192,7 +192,7 @@ int autofs4_fill_super(struct super_bloc
 	sbi->magic = AUTOFS_SBI_MAGIC;
 	sbi->catatonic = 0;
 	sbi->exp_timeout = 0;
-	sbi->oz_pgrp = current->pgrp;
+	sbi->oz_pgrp = current->group_leader->pgrp;
 	sbi->sb = s;
 	sbi->version = 0;
 	sbi->queues = NULL;
diff -puN fs/autofs4/root.c~pgrp fs/autofs4/root.c
--- local-2.6/fs/autofs4/root.c~pgrp	2003-09-08 18:19:32.000000000 -0700
+++ local-2.6-jeremy/fs/autofs4/root.c	2003-09-08 18:19:32.000000000 -0700
@@ -255,7 +255,7 @@ static struct dentry *autofs4_root_looku
 	lock_kernel();
 	oz_mode = autofs4_oz_mode(sbi);
 	DPRINTK(("autofs_lookup: pid = %u, pgrp = %u, catatonic = %d, oz_mode = %d\n",
-		 current->pid, current->pgrp, sbi->catatonic, oz_mode));
+		 current->pid, current->group_leader->pgrp, sbi->catatonic, oz_mode));
 
 	/*
 	 * Mark the dentry incomplete, but add it. This is needed so
@@ -518,7 +518,7 @@ static int autofs4_root_ioctl(struct ino
 	struct autofs_sb_info *sbi = autofs4_sbi(inode->i_sb);
 
 	DPRINTK(("autofs_ioctl: cmd = 0x%08x, arg = 0x%08lx, sbi = %p, pgrp = %u\n",
-		 cmd,arg,sbi,current->pgrp));
+		 cmd,arg,sbi,current->group_leader->pgrp));
 
 	if ( _IOC_TYPE(cmd) != _IOC_TYPE(AUTOFS_IOC_FIRST) ||
 	     _IOC_NR(cmd) - _IOC_NR(AUTOFS_IOC_FIRST) >= AUTOFS_IOC_COUNT )
diff -puN fs/binfmt_elf.c~pgrp fs/binfmt_elf.c
--- local-2.6/fs/binfmt_elf.c~pgrp	2003-09-08 18:19:32.000000000 -0700
+++ local-2.6-jeremy/fs/binfmt_elf.c	2003-09-08 18:19:32.000000000 -0700
@@ -1076,7 +1076,7 @@ static void fill_prstatus(struct elf_prs
 	prstatus->pr_sighold = p->blocked.sig[0];
 	prstatus->pr_pid = p->pid;
 	prstatus->pr_ppid = p->parent->pid;
-	prstatus->pr_pgrp = p->pgrp;
+	prstatus->pr_pgrp = p->group_leader->pgrp;
 	prstatus->pr_sid = p->session;
 	jiffies_to_timeval(p->utime, &prstatus->pr_utime);
 	jiffies_to_timeval(p->stime, &prstatus->pr_stime);
@@ -1104,7 +1104,7 @@ static void fill_psinfo(struct elf_prpsi
 
 	psinfo->pr_pid = p->pid;
 	psinfo->pr_ppid = p->parent->pid;
-	psinfo->pr_pgrp = p->pgrp;
+	psinfo->pr_pgrp = p->group_leader->pgrp;
 	psinfo->pr_sid = p->session;
 
 	i = p->state ? ffz(~p->state) + 1 : 0;
diff -puN fs/coda/upcall.c~pgrp fs/coda/upcall.c
--- local-2.6/fs/coda/upcall.c~pgrp	2003-09-08 18:19:32.000000000 -0700
+++ local-2.6-jeremy/fs/coda/upcall.c	2003-09-08 18:19:32.000000000 -0700
@@ -54,7 +54,7 @@ static void *alloc_upcall(int opcode, in
 
         inp->ih.opcode = opcode;
 	inp->ih.pid = current->pid;
-	inp->ih.pgid = current->pgrp;
+	inp->ih.pgid = current->group_leader->pgrp;
 	coda_load_creds(&(inp->ih.cred));
 
 	return (void*)inp;
diff -puN fs/devfs/base.c~pgrp fs/devfs/base.c
--- local-2.6/fs/devfs/base.c~pgrp	2003-09-08 18:19:32.000000000 -0700
+++ local-2.6-jeremy/fs/devfs/base.c	2003-09-08 18:19:32.000000000 -0700
@@ -1334,7 +1334,7 @@ static int is_devfsd_or_child (struct fs
     struct task_struct *p = current;
 
     if (p == fs_info->devfsd_task) return (TRUE);
-    if (p->pgrp == fs_info->devfsd_pgrp) return (TRUE);
+    if (p->group_leader->pgrp == fs_info->devfsd_pgrp) return (TRUE);
     read_lock(&tasklist_lock);
     for ( ; p != &init_task; p = p->real_parent)
     {
@@ -2745,8 +2745,8 @@ static int devfsd_ioctl (struct inode *i
 	    }
 	    fs_info->devfsd_task = current;
 	    spin_unlock (&lock);
-	    fs_info->devfsd_pgrp = (current->pgrp == current->pid) ?
-		current->pgrp : 0;
+	    fs_info->devfsd_pgrp = (current->group_leader->pgrp == current->pid) ?
+		current->group_leader->pgrp : 0;
 	    fs_info->devfsd_file = file;
 	    fs_info->devfsd_info = kmalloc (sizeof *fs_info->devfsd_info,
 					    GFP_KERNEL);
diff -puN fs/proc/array.c~pgrp fs/proc/array.c
--- local-2.6/fs/proc/array.c~pgrp	2003-09-08 18:19:32.000000000 -0700
+++ local-2.6-jeremy/fs/proc/array.c	2003-09-08 18:19:32.000000000 -0700
@@ -344,7 +344,7 @@ int proc_pid_stat(struct task_struct *ta
 		task->comm,
 		state,
 		ppid,
-		task->pgrp,
+		task->group_leader->pgrp,
 		task->session,
 		tty_nr,
 		tty_pgrp,
diff -puN kernel/exit.c~pgrp kernel/exit.c
--- local-2.6/kernel/exit.c~pgrp	2003-09-08 18:19:32.000000000 -0700
+++ local-2.6-jeremy/kernel/exit.c	2003-09-08 18:19:32.000000000 -0700
@@ -152,7 +152,7 @@ static int will_become_orphaned_pgrp(int
 				|| p->state >= TASK_ZOMBIE 
 				|| p->real_parent->pid == 1)
 			continue;
-		if (p->real_parent->pgrp != pgrp
+		if (p->real_parent->group_leader->pgrp != pgrp
 			    && p->real_parent->session == p->session) {
 			ret = 0;
 			break;
@@ -247,9 +247,9 @@ void __set_special_pids(pid_t session, p
 		curr->session = session;
 		attach_pid(curr, PIDTYPE_SID, session);
 	}
-	if (curr->pgrp != pgrp) {
+	if (curr->group_leader->pgrp != pgrp) {
 		detach_pid(curr, PIDTYPE_PGID);
-		curr->pgrp = pgrp;
+		curr->group_leader->pgrp = pgrp;
 		attach_pid(curr, PIDTYPE_PGID, pgrp);
 	}
 }
@@ -618,12 +618,12 @@ static void exit_notify(struct task_stru
 	 
 	t = tsk->real_parent;
 	
-	if ((t->pgrp != tsk->pgrp) &&
+	if ((t->group_leader->pgrp != tsk->group_leader->pgrp) &&
 	    (t->session == tsk->session) &&
-	    will_become_orphaned_pgrp(tsk->pgrp, tsk) &&
-	    has_stopped_jobs(tsk->pgrp)) {
-		__kill_pg_info(SIGHUP, (void *)1, tsk->pgrp);
-		__kill_pg_info(SIGCONT, (void *)1, tsk->pgrp);
+	    will_become_orphaned_pgrp(tsk->group_leader->pgrp, tsk) &&
+	    has_stopped_jobs(tsk->group_leader->pgrp)) {
+		__kill_pg_info(SIGHUP, (void *)1, tsk->group_leader->pgrp);
+		__kill_pg_info(SIGCONT, (void *)1, tsk->group_leader->pgrp);
 	}
 
 	/* Let father know we died 
@@ -813,10 +813,10 @@ static int eligible_child(pid_t pid, int
 		if (p->pid != pid)
 			return 0;
 	} else if (!pid) {
-		if (p->pgrp != current->pgrp)
+		if (p->group_leader->pgrp != current->group_leader->pgrp)
 			return 0;
 	} else if (pid != -1) {
-		if (p->pgrp != -pid)
+		if (p->group_leader->pgrp != -pid)
 			return 0;
 	}
 
diff -puN kernel/pid.c~pgrp kernel/pid.c
--- local-2.6/kernel/pid.c~pgrp	2003-09-08 18:19:32.000000000 -0700
+++ local-2.6-jeremy/kernel/pid.c	2003-09-08 18:19:32.000000000 -0700
@@ -250,7 +250,7 @@ void switch_exec_pids(task_t *leader, ta
 
 	attach_pid(thread, PIDTYPE_PID, thread->pid);
 	attach_pid(thread, PIDTYPE_TGID, thread->tgid);
-	attach_pid(thread, PIDTYPE_PGID, thread->pgrp);
+	attach_pid(thread, PIDTYPE_PGID, leader->pgrp);
 	attach_pid(thread, PIDTYPE_SID, thread->session);
 	list_add_tail(&thread->tasks, &init_task.tasks);
 
diff -puN kernel/signal.c~pgrp kernel/signal.c
--- local-2.6/kernel/signal.c~pgrp	2003-09-08 18:19:32.000000000 -0700
+++ local-2.6-jeremy/kernel/signal.c	2003-09-08 18:19:32.000000000 -0700
@@ -1139,7 +1139,7 @@ kill_proc_info(int sig, struct siginfo *
 static int kill_something_info(int sig, struct siginfo *info, int pid)
 {
 	if (!pid) {
-		return kill_pg_info(sig, info, current->pgrp);
+		return kill_pg_info(sig, info, current->group_leader->pgrp);
 	} else if (pid == -1) {
 		int retval = 0, count = 0;
 		struct task_struct * p;
@@ -1798,7 +1798,7 @@ relock:
 
 			/* signals can be posted during this window */
 
-			if (is_orphaned_pgrp(current->pgrp))
+			if (is_orphaned_pgrp(current->group_leader->pgrp))
 				goto relock;
 
 			spin_lock_irq(&current->sighand->siglock);
diff -puN kernel/sys.c~pgrp kernel/sys.c
--- local-2.6/kernel/sys.c~pgrp	2003-09-08 18:19:32.000000000 -0700
+++ local-2.6-jeremy/kernel/sys.c	2003-09-08 18:40:17.000000000 -0700
@@ -290,7 +290,7 @@ asmlinkage long sys_setpriority(int whic
 			break;
 		case PRIO_PGRP:
 			if (!who)
-				who = current->pgrp;
+				who = current->group_leader->pgrp;
 			for_each_task_pid(who, PIDTYPE_PGID, p, l, pid)
 				error = set_one_prio(p, niceval, error);
 			break;
@@ -346,7 +346,7 @@ asmlinkage long sys_getpriority(int whic
 			break;
 		case PRIO_PGRP:
 			if (!who)
-				who = current->pgrp;
+				who = current->group_leader->pgrp;
 			for_each_task_pid(who, PIDTYPE_PGID, p, l, pid) {
 				niceval = 20 - task_nice(p);
 				if (niceval > retval)
@@ -985,17 +985,6 @@ ok_pgid:
 		attach_pid(p, PIDTYPE_PGID, pgid);
 	}
 
-	{
-		/* update all threads in thread group
-		   to new process group */
-		struct task_struct *p;
-		struct pid *pidp;
-		struct list_head *l;
-
-		for_each_task_pid(pid, PIDTYPE_TGID, p, l, pidp)
-			p->pgrp = pgid;
-	}
-
 	err = 0;
 out:
 	/* All paths lead to here, thus we are safe. -DaveM */
@@ -1006,7 +995,7 @@ out:
 asmlinkage long sys_getpgid(pid_t pid)
 {
 	if (!pid) {
-		return current->pgrp;
+		return current->group_leader->pgrp;
 	} else {
 		int retval;
 		struct task_struct *p;
@@ -1018,7 +1007,7 @@ asmlinkage long sys_getpgid(pid_t pid)
 		if (p) {
 			retval = security_task_getpgid(p);
 			if (!retval)
-				retval = p->pgrp;
+				retval = p->group_leader->pgrp;
 		}
 		read_unlock(&tasklist_lock);
 		return retval;
@@ -1028,7 +1017,7 @@ asmlinkage long sys_getpgid(pid_t pid)
 asmlinkage long sys_getpgrp(void)
 {
 	/* SMP - assuming writes are word atomic this is fine */
-	return current->pgrp;
+	return current->group_leader->pgrp;
 }
 
 asmlinkage long sys_getsid(pid_t pid)

_

Re: [PATCH] use group_leader->pgrp (was Re: setpgid and threads)

[Andrew Morton]

Jeremy Fitzhardinge <jeremy@goop.org> wrote:
>
> On Wed, 2003-08-20 at 19:49, Andrew Morton wrote:
> > Using current->thread_group->foo sounds like a reasonable solution
> 
> Here's a patch to use group_leader->pgrp rather than just ->pgrp so that
> all threads in a group appear to have the same process group ID.

Just a quick maintainance thing:


> -				if (is_orphaned_pgrp(current->pgrp))
> +				if (is_orphaned_pgrp(current->group_leader->pgrp))

Would it make sense to do this via

	if (is_orphaned_pgrp(process_group(current)))

and to then rename task_struct.pgrp to something else, to pick up any
missed conversions?

Re: [PATCH] use group_leader->pgrp (was Re: setpgid and threads)

[Jeremy Fitzhardinge]

On Mon, 2003-09-08 at 19:12, Andrew Morton wrote:
> and to then rename task_struct.pgrp to something else, to pick up any
> missed conversions?

Probably a good idea.  I was also thinking about renaming "group_leader"
to something which tells you which kind of group its the leader of.  Or
at least commenting it.

	J

Re: [PATCH] use group_leader->pgrp (was Re: setpgid and threads)

[Andrew Morton]

Jeremy Fitzhardinge <jeremy@goop.org> wrote:
>
> On Mon, 2003-09-08 at 19:12, Andrew Morton wrote:
> > and to then rename task_struct.pgrp to something else, to pick up any
> > missed conversions?
> 
> Probably a good idea.

Caught a few:

drivers/char/tty_io.c: In function `tty_check_change':
drivers/char/tty_io.c:332: structure has no member named `pgrp'
drivers/char/tty_io.c:334: structure has no member named `pgrp'

	if (is_orphaned_pgrp(current->pgrp))
		return -EIO;
	(void) kill_pg(current->pgrp,SIGTTOU,1);

should these be converted?


drivers/char/tty_io.c: In function `tty_open':
drivers/char/tty_io.c:1409: structure has no member named `pgrp'

		tty->pgrp = current->pgrp;

this one?

drivers/char/tty_io.c: In function `tiocsctty':
drivers/char/tty_io.c:1583: structure has no member named `pgrp'

        tty->pgrp = current->pgrp;

and this.  I think so?

Re: [PATCH] use group_leader->pgrp (was Re: setpgid and threads)

[Ulrich Drepper]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Andrew Morton wrote:
> I think so?

Definitely.  All occurrences have to be changed.

- -- 
- --------------.                        ,-.            444 Castro Street
Ulrich Drepper \    ,-----------------'   \ Mountain View, CA 94041 USA
Red Hat         `--' drepper at redhat.com `---------------------------
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.2.1 (GNU/Linux)

iD8DBQE/XU762ijCOnn/RHQRAivlAJ44IyipfOulKbyIXFc2KtKNAChnAACcD9IP
Di3DV6lM6+59ujhFwYK41mE=
=6Ofq
-----END PGP SIGNATURE-----

Re: [PATCH] use group_leader->pgrp (was Re: setpgid and threads)

[Andrew Morton]

Ulrich Drepper <drepper@redhat.com> wrote:
>
>  Definitely.  All occurrences have to be changed.

OK.  There were a few missing ones.  Here's what I have, against test5.  Do
you have a test suite which would give us reasonable confidence?

Could you please grep for `__pgrp' and make sure that we got everything
right there?

All other instances of foo->pgrp have been converted to process_group(foo),
which is foo->group_leader->__pgrp.

Should setpgrp() in a thread affect the group leader?   It does...


 arch/h8300/kernel/signal.c     |    2 +-
 arch/m68k/kernel/signal.c      |    2 +-
 arch/m68knommu/kernel/signal.c |    2 +-
 arch/mips/kernel/irixelf.c     |    2 +-
 arch/mips/kernel/irixsig.c     |    2 +-
 arch/mips/kernel/sysirix.c     |    4 ++--
 arch/sparc64/solaris/misc.c    |    4 ++--
 drivers/char/n_tty.c           |    6 +++---
 drivers/char/rocket.c          |    2 +-
 drivers/char/tty_io.c          |   10 +++++-----
 fs/autofs/autofs_i.h           |    2 +-
 fs/autofs/inode.c              |    2 +-
 fs/autofs/root.c               |    4 ++--
 fs/autofs4/autofs_i.h          |    2 +-
 fs/autofs4/inode.c             |    4 ++--
 fs/autofs4/root.c              |    4 ++--
 fs/binfmt_elf.c                |    4 ++--
 fs/coda/upcall.c               |    2 +-
 fs/devfs/base.c                |    6 +++---
 fs/proc/array.c                |    2 +-
 include/linux/sched.h          |    7 ++++++-
 kernel/exit.c                  |   24 ++++++++++++------------
 kernel/fork.c                  |    2 +-
 kernel/pid.c                   |    4 ++--
 kernel/signal.c                |    4 ++--
 kernel/sys.c                   |   17 +++++++++--------
 26 files changed, 66 insertions(+), 60 deletions(-)

diff -puN kernel/sys.c~group_leader-rework kernel/sys.c
--- 25/kernel/sys.c~group_leader-rework	2003-09-08 21:12:46.000000000 -0700
+++ 25-akpm/kernel/sys.c	2003-09-08 21:12:46.000000000 -0700
@@ -290,7 +290,7 @@ asmlinkage long sys_setpriority(int whic
 			break;
 		case PRIO_PGRP:
 			if (!who)
-				who = current->pgrp;
+				who = process_group(current);
 			for_each_task_pid(who, PIDTYPE_PGID, p, l, pid)
 				error = set_one_prio(p, niceval, error);
 			break;
@@ -346,7 +346,7 @@ asmlinkage long sys_getpriority(int whic
 			break;
 		case PRIO_PGRP:
 			if (!who)
-				who = current->pgrp;
+				who = process_group(current);
 			for_each_task_pid(who, PIDTYPE_PGID, p, l, pid) {
 				niceval = 20 - task_nice(p);
 				if (niceval > retval)
@@ -979,11 +979,12 @@ ok_pgid:
 	if (err)
 		goto out;
 
-	if (p->pgrp != pgid) {
+	if (process_group(p) != pgid) {
 		detach_pid(p, PIDTYPE_PGID);
-		p->pgrp = pgid;
+		p->group_leader->__pgrp = pgid;
 		attach_pid(p, PIDTYPE_PGID, pgid);
 	}
+
 	err = 0;
 out:
 	/* All paths lead to here, thus we are safe. -DaveM */
@@ -994,7 +995,7 @@ out:
 asmlinkage long sys_getpgid(pid_t pid)
 {
 	if (!pid) {
-		return current->pgrp;
+		return process_group(current);
 	} else {
 		int retval;
 		struct task_struct *p;
@@ -1006,7 +1007,7 @@ asmlinkage long sys_getpgid(pid_t pid)
 		if (p) {
 			retval = security_task_getpgid(p);
 			if (!retval)
-				retval = p->pgrp;
+				retval = process_group(p);
 		}
 		read_unlock(&tasklist_lock);
 		return retval;
@@ -1016,7 +1017,7 @@ asmlinkage long sys_getpgid(pid_t pid)
 asmlinkage long sys_getpgrp(void)
 {
 	/* SMP - assuming writes are word atomic this is fine */
-	return current->pgrp;
+	return process_group(current);
 }
 
 asmlinkage long sys_getsid(pid_t pid)
@@ -1059,7 +1060,7 @@ asmlinkage long sys_setsid(void)
 	__set_special_pids(current->pid, current->pid);
 	current->tty = NULL;
 	current->tty_old_pgrp = 0;
-	err = current->pgrp;
+	err = process_group(current);
 out:
 	write_unlock_irq(&tasklist_lock);
 	return err;
diff -puN arch/h8300/kernel/signal.c~group_leader-rework arch/h8300/kernel/signal.c
--- 25/arch/h8300/kernel/signal.c~group_leader-rework	2003-09-08 21:12:46.000000000 -0700
+++ 25-akpm/arch/h8300/kernel/signal.c	2003-09-08 21:12:46.000000000 -0700
@@ -593,7 +593,7 @@ asmlinkage int do_signal(sigset_t *oldse
 				continue;
 
 			case SIGTSTP: case SIGTTIN: case SIGTTOU:
-				if (is_orphaned_pgrp(current->pgrp))
+				if (is_orphaned_pgrp(process_group(current)))
 					continue;
 				/* FALLTHRU */
 
diff -puN arch/m68k/kernel/signal.c~group_leader-rework arch/m68k/kernel/signal.c
--- 25/arch/m68k/kernel/signal.c~group_leader-rework	2003-09-08 21:12:46.000000000 -0700
+++ 25-akpm/arch/m68k/kernel/signal.c	2003-09-08 21:12:46.000000000 -0700
@@ -1082,7 +1082,7 @@ asmlinkage int do_signal(sigset_t *oldse
 				continue;
 
 			case SIGTSTP: case SIGTTIN: case SIGTTOU:
-				if (is_orphaned_pgrp(current->pgrp))
+				if (is_orphaned_pgrp(process_group(current)))
 					continue;
 				/* FALLTHRU */
 
diff -puN arch/m68knommu/kernel/signal.c~group_leader-rework arch/m68knommu/kernel/signal.c
--- 25/arch/m68knommu/kernel/signal.c~group_leader-rework	2003-09-08 21:12:46.000000000 -0700
+++ 25-akpm/arch/m68knommu/kernel/signal.c	2003-09-08 21:12:46.000000000 -0700
@@ -841,7 +841,7 @@ asmlinkage int do_signal(sigset_t *oldse
 				continue;
 
 			case SIGTSTP: case SIGTTIN: case SIGTTOU:
-				if (is_orphaned_pgrp(current->pgrp))
+				if (is_orphaned_pgrp(process_group(current)))
 					continue;
 				/* FALLTHRU */
 
diff -puN arch/mips/kernel/irixelf.c~group_leader-rework arch/mips/kernel/irixelf.c
--- 25/arch/mips/kernel/irixelf.c~group_leader-rework	2003-09-08 21:12:46.000000000 -0700
+++ 25-akpm/arch/mips/kernel/irixelf.c	2003-09-08 21:12:46.000000000 -0700
@@ -1129,7 +1129,7 @@ static int irix_core_dump(long signr, st
 	prstatus.pr_sighold = current->blocked.sig[0];
 	psinfo.pr_pid = prstatus.pr_pid = current->pid;
 	psinfo.pr_ppid = prstatus.pr_ppid = current->parent->pid;
-	psinfo.pr_pgrp = prstatus.pr_pgrp = current->pgrp;
+	psinfo.pr_pgrp = prstatus.pr_pgrp = process_group(current);
 	psinfo.pr_sid = prstatus.pr_sid = current->session;
 	prstatus.pr_utime.tv_sec = CT_TO_SECS(current->utime);
 	prstatus.pr_utime.tv_usec = CT_TO_USECS(current->utime);
diff -puN arch/mips/kernel/irixsig.c~group_leader-rework arch/mips/kernel/irixsig.c
--- 25/arch/mips/kernel/irixsig.c~group_leader-rework	2003-09-08 21:12:46.000000000 -0700
+++ 25-akpm/arch/mips/kernel/irixsig.c	2003-09-08 21:12:46.000000000 -0700
@@ -582,7 +582,7 @@ repeat:
 		p = list_entry(_p,struct task_struct,sibling);
 		if ((type == P_PID) && p->pid != pid)
 			continue;
-		if ((type == P_PGID) && p->pgrp != pid)
+		if ((type == P_PGID) && process_group(p) != pid)
 			continue;
 		if ((p->exit_signal != SIGCHLD))
 			continue;
diff -puN arch/mips/kernel/sysirix.c~group_leader-rework arch/mips/kernel/sysirix.c
--- 25/arch/mips/kernel/sysirix.c~group_leader-rework	2003-09-08 21:12:46.000000000 -0700
+++ 25-akpm/arch/mips/kernel/sysirix.c	2003-09-08 21:12:46.000000000 -0700
@@ -803,11 +803,11 @@ asmlinkage int irix_setpgrp(int flags)
 	printk("[%s:%d] setpgrp(%d) ", current->comm, current->pid, flags);
 #endif
 	if(!flags)
-		error = current->pgrp;
+		error = process_group(current);
 	else
 		error = sys_setsid();
 #ifdef DEBUG_PROCGRPS
-	printk("returning %d\n", current->pgrp);
+	printk("returning %d\n", process_group(current));
 #endif
 
 	return error;
diff -puN arch/sparc64/solaris/misc.c~group_leader-rework arch/sparc64/solaris/misc.c
--- 25/arch/sparc64/solaris/misc.c~group_leader-rework	2003-09-08 21:12:46.000000000 -0700
+++ 25-akpm/arch/sparc64/solaris/misc.c	2003-09-08 21:12:46.000000000 -0700
@@ -392,7 +392,7 @@ asmlinkage int solaris_procids(int cmd, 
 	
 	switch (cmd) {
 	case 0: /* getpgrp */
-		return current->pgrp;
+		return process_group(current);
 	case 1: /* setpgrp */
 		{
 			int (*sys_setpgid)(pid_t,pid_t) =
@@ -403,7 +403,7 @@ asmlinkage int solaris_procids(int cmd, 
 			ret = sys_setpgid(0, 0);
 			if (ret) return ret;
 			current->tty = NULL;
-			return current->pgrp;
+			return process_group(current);
 		}
 	case 2: /* getsid */
 		{
diff -puN drivers/char/n_tty.c~group_leader-rework drivers/char/n_tty.c
--- 25/drivers/char/n_tty.c~group_leader-rework	2003-09-08 21:12:46.000000000 -0700
+++ 25-akpm/drivers/char/n_tty.c	2003-09-08 21:12:46.000000000 -0700
@@ -977,11 +977,11 @@ do_it_again:
 	if (file->f_op->write != redirected_tty_write && current->tty == tty) {
 		if (tty->pgrp <= 0)
 			printk("read_chan: tty->pgrp <= 0!\n");
-		else if (current->pgrp != tty->pgrp) {
+		else if (process_group(current) != tty->pgrp) {
 			if (is_ignored(SIGTTIN) ||
-			    is_orphaned_pgrp(current->pgrp))
+			    is_orphaned_pgrp(process_group(current)))
 				return -EIO;
-			kill_pg(current->pgrp, SIGTTIN, 1);
+			kill_pg(process_group(current), SIGTTIN, 1);
 			return -ERESTARTSYS;
 		}
 	}
diff -puN drivers/char/rocket.c~group_leader-rework drivers/char/rocket.c
--- 25/drivers/char/rocket.c~group_leader-rework	2003-09-08 21:12:46.000000000 -0700
+++ 25-akpm/drivers/char/rocket.c	2003-09-08 21:12:46.000000000 -0700
@@ -956,7 +956,7 @@ static int rp_open(struct tty_struct *tt
 	 * Info->count is now 1; so it's safe to sleep now.
 	 */
 	info->session = current->session;
-	info->pgrp = current->pgrp;
+	info->pgrp = process_group(current);
 
 	if ((info->flags & ROCKET_INITIALIZED) == 0) {
 		cp = &info->channel;
diff -puN drivers/char/tty_io.c~group_leader-rework drivers/char/tty_io.c
--- 25/drivers/char/tty_io.c~group_leader-rework	2003-09-08 21:12:46.000000000 -0700
+++ 25-akpm/drivers/char/tty_io.c	2003-09-08 21:12:46.000000000 -0700
@@ -325,13 +325,13 @@ int tty_check_change(struct tty_struct *
 		printk(KERN_WARNING "tty_check_change: tty->pgrp <= 0!\n");
 		return 0;
 	}
-	if (current->pgrp == tty->pgrp)
+	if (process_group(current) == tty->pgrp)
 		return 0;
 	if (is_ignored(SIGTTOU))
 		return 0;
-	if (is_orphaned_pgrp(current->pgrp))
+	if (is_orphaned_pgrp(process_group(current)))
 		return -EIO;
-	(void) kill_pg(current->pgrp,SIGTTOU,1);
+	(void) kill_pg(process_group(current), SIGTTOU, 1);
 	return -ERESTARTSYS;
 }
 
@@ -1406,7 +1406,7 @@ got_driver:
 		task_unlock(current);
 		current->tty_old_pgrp = 0;
 		tty->session = current->session;
-		tty->pgrp = current->pgrp;
+		tty->pgrp = process_group(current);
 	}
 	return 0;
 }
@@ -1580,7 +1580,7 @@ static int tiocsctty(struct tty_struct *
 	task_unlock(current);
 	current->tty_old_pgrp = 0;
 	tty->session = current->session;
-	tty->pgrp = current->pgrp;
+	tty->pgrp = process_group(current);
 	return 0;
 }
 
diff -puN fs/autofs4/autofs_i.h~group_leader-rework fs/autofs4/autofs_i.h
--- 25/fs/autofs4/autofs_i.h~group_leader-rework	2003-09-08 21:12:46.000000000 -0700
+++ 25-akpm/fs/autofs4/autofs_i.h	2003-09-08 21:12:46.000000000 -0700
@@ -113,7 +113,7 @@ static inline struct autofs_info *autofs
    filesystem without "magic".) */
 
 static inline int autofs4_oz_mode(struct autofs_sb_info *sbi) {
-	return sbi->catatonic || current->pgrp == sbi->oz_pgrp;
+	return sbi->catatonic || process_group(current) == sbi->oz_pgrp;
 }
 
 /* Does a dentry have some pending activity? */
diff -puN fs/autofs4/inode.c~group_leader-rework fs/autofs4/inode.c
--- 25/fs/autofs4/inode.c~group_leader-rework	2003-09-08 21:12:46.000000000 -0700
+++ 25-akpm/fs/autofs4/inode.c	2003-09-08 21:12:46.000000000 -0700
@@ -101,7 +101,7 @@ static int parse_options(char *options, 
 	
 	*uid = current->uid;
 	*gid = current->gid;
-	*pgrp = current->pgrp;
+	*pgrp = process_group(current);
 
 	*minproto = AUTOFS_MIN_PROTO_VERSION;
 	*maxproto = AUTOFS_MAX_PROTO_VERSION;
@@ -192,7 +192,7 @@ int autofs4_fill_super(struct super_bloc
 	sbi->magic = AUTOFS_SBI_MAGIC;
 	sbi->catatonic = 0;
 	sbi->exp_timeout = 0;
-	sbi->oz_pgrp = current->pgrp;
+	sbi->oz_pgrp = process_group(current);
 	sbi->sb = s;
 	sbi->version = 0;
 	sbi->queues = NULL;
diff -puN fs/autofs4/root.c~group_leader-rework fs/autofs4/root.c
--- 25/fs/autofs4/root.c~group_leader-rework	2003-09-08 21:12:46.000000000 -0700
+++ 25-akpm/fs/autofs4/root.c	2003-09-08 21:12:46.000000000 -0700
@@ -255,7 +255,7 @@ static struct dentry *autofs4_root_looku
 	lock_kernel();
 	oz_mode = autofs4_oz_mode(sbi);
 	DPRINTK(("autofs_lookup: pid = %u, pgrp = %u, catatonic = %d, oz_mode = %d\n",
-		 current->pid, current->pgrp, sbi->catatonic, oz_mode));
+		 current->pid, process_group(current), sbi->catatonic, oz_mode));
 
 	/*
 	 * Mark the dentry incomplete, but add it. This is needed so
@@ -518,7 +518,7 @@ static int autofs4_root_ioctl(struct ino
 	struct autofs_sb_info *sbi = autofs4_sbi(inode->i_sb);
 
 	DPRINTK(("autofs_ioctl: cmd = 0x%08x, arg = 0x%08lx, sbi = %p, pgrp = %u\n",
-		 cmd,arg,sbi,current->pgrp));
+		 cmd,arg,sbi,process_group(current)));
 
 	if ( _IOC_TYPE(cmd) != _IOC_TYPE(AUTOFS_IOC_FIRST) ||
 	     _IOC_NR(cmd) - _IOC_NR(AUTOFS_IOC_FIRST) >= AUTOFS_IOC_COUNT )
diff -puN fs/autofs/autofs_i.h~group_leader-rework fs/autofs/autofs_i.h
--- 25/fs/autofs/autofs_i.h~group_leader-rework	2003-09-08 21:12:46.000000000 -0700
+++ 25-akpm/fs/autofs/autofs_i.h	2003-09-08 21:12:46.000000000 -0700
@@ -123,7 +123,7 @@ static inline struct autofs_sb_info *aut
    filesystem without "magic".) */
 
 static inline int autofs_oz_mode(struct autofs_sb_info *sbi) {
-	return sbi->catatonic || current->pgrp == sbi->oz_pgrp;
+	return sbi->catatonic || process_group(current) == sbi->oz_pgrp;
 }
 
 /* Hash operations */
diff -puN fs/autofs/inode.c~group_leader-rework fs/autofs/inode.c
--- 25/fs/autofs/inode.c~group_leader-rework	2003-09-08 21:12:46.000000000 -0700
+++ 25-akpm/fs/autofs/inode.c	2003-09-08 21:12:46.000000000 -0700
@@ -51,7 +51,7 @@ static int parse_options(char *options, 
 	
 	*uid = current->uid;
 	*gid = current->gid;
-	*pgrp = current->pgrp;
+	*pgrp = process_group(current);
 
 	*minproto = *maxproto = AUTOFS_PROTO_VERSION;
 
diff -puN fs/autofs/root.c~group_leader-rework fs/autofs/root.c
--- 25/fs/autofs/root.c~group_leader-rework	2003-09-08 21:12:46.000000000 -0700
+++ 25-akpm/fs/autofs/root.c	2003-09-08 21:12:46.000000000 -0700
@@ -213,7 +213,7 @@ static struct dentry *autofs_root_lookup
 
 	oz_mode = autofs_oz_mode(sbi);
 	DPRINTK(("autofs_lookup: pid = %u, pgrp = %u, catatonic = %d, oz_mode = %d\n",
-		 current->pid, current->pgrp, sbi->catatonic, oz_mode));
+		 current->pid, process_group(current), sbi->catatonic, oz_mode));
 
 	/*
 	 * Mark the dentry incomplete, but add it. This is needed so
@@ -527,7 +527,7 @@ static int autofs_root_ioctl(struct inod
 {
 	struct autofs_sb_info *sbi = autofs_sbi(inode->i_sb);
 
-	DPRINTK(("autofs_ioctl: cmd = 0x%08x, arg = 0x%08lx, sbi = %p, pgrp = %u\n",cmd,arg,sbi,current->pgrp));
+	DPRINTK(("autofs_ioctl: cmd = 0x%08x, arg = 0x%08lx, sbi = %p, pgrp = %u\n",cmd,arg,sbi,process_group(current)));
 
 	if ( _IOC_TYPE(cmd) != _IOC_TYPE(AUTOFS_IOC_FIRST) ||
 	     _IOC_NR(cmd) - _IOC_NR(AUTOFS_IOC_FIRST) >= AUTOFS_IOC_COUNT )
diff -puN fs/binfmt_elf.c~group_leader-rework fs/binfmt_elf.c
--- 25/fs/binfmt_elf.c~group_leader-rework	2003-09-08 21:12:46.000000000 -0700
+++ 25-akpm/fs/binfmt_elf.c	2003-09-08 21:12:46.000000000 -0700
@@ -1076,7 +1076,7 @@ static void fill_prstatus(struct elf_prs
 	prstatus->pr_sighold = p->blocked.sig[0];
 	prstatus->pr_pid = p->pid;
 	prstatus->pr_ppid = p->parent->pid;
-	prstatus->pr_pgrp = p->pgrp;
+	prstatus->pr_pgrp = process_group(p);
 	prstatus->pr_sid = p->session;
 	jiffies_to_timeval(p->utime, &prstatus->pr_utime);
 	jiffies_to_timeval(p->stime, &prstatus->pr_stime);
@@ -1104,7 +1104,7 @@ static void fill_psinfo(struct elf_prpsi
 
 	psinfo->pr_pid = p->pid;
 	psinfo->pr_ppid = p->parent->pid;
-	psinfo->pr_pgrp = p->pgrp;
+	psinfo->pr_pgrp = process_group(p);
 	psinfo->pr_sid = p->session;
 
 	i = p->state ? ffz(~p->state) + 1 : 0;
diff -puN fs/coda/upcall.c~group_leader-rework fs/coda/upcall.c
--- 25/fs/coda/upcall.c~group_leader-rework	2003-09-08 21:12:46.000000000 -0700
+++ 25-akpm/fs/coda/upcall.c	2003-09-08 21:12:46.000000000 -0700
@@ -54,7 +54,7 @@ static void *alloc_upcall(int opcode, in
 
         inp->ih.opcode = opcode;
 	inp->ih.pid = current->pid;
-	inp->ih.pgid = current->pgrp;
+	inp->ih.pgid = process_group(current);
 	coda_load_creds(&(inp->ih.cred));
 
 	return (void*)inp;
diff -puN fs/devfs/base.c~group_leader-rework fs/devfs/base.c
--- 25/fs/devfs/base.c~group_leader-rework	2003-09-08 21:12:46.000000000 -0700
+++ 25-akpm/fs/devfs/base.c	2003-09-08 21:12:46.000000000 -0700
@@ -1334,7 +1334,7 @@ static int is_devfsd_or_child (struct fs
     struct task_struct *p = current;
 
     if (p == fs_info->devfsd_task) return (TRUE);
-    if (p->pgrp == fs_info->devfsd_pgrp) return (TRUE);
+    if (process_group(p) == fs_info->devfsd_pgrp) return (TRUE);
     read_lock(&tasklist_lock);
     for ( ; p != &init_task; p = p->real_parent)
     {
@@ -2744,8 +2744,8 @@ static int devfsd_ioctl (struct inode *i
 	    }
 	    fs_info->devfsd_task = current;
 	    spin_unlock (&lock);
-	    fs_info->devfsd_pgrp = (current->pgrp == current->pid) ?
-		current->pgrp : 0;
+	    fs_info->devfsd_pgrp = (process_group(current) == current->pid) ?
+		process_group(current) : 0;
 	    fs_info->devfsd_file = file;
 	    fs_info->devfsd_info = kmalloc (sizeof *fs_info->devfsd_info,
 					    GFP_KERNEL);
diff -puN fs/proc/array.c~group_leader-rework fs/proc/array.c
--- 25/fs/proc/array.c~group_leader-rework	2003-09-08 21:12:46.000000000 -0700
+++ 25-akpm/fs/proc/array.c	2003-09-08 21:12:46.000000000 -0700
@@ -341,7 +341,7 @@ int proc_pid_stat(struct task_struct *ta
 		task->comm,
 		state,
 		ppid,
-		task->pgrp,
+		process_group(task),
 		task->session,
 		tty_nr,
 		tty_pgrp,
diff -puN kernel/exit.c~group_leader-rework kernel/exit.c
--- 25/kernel/exit.c~group_leader-rework	2003-09-08 21:12:46.000000000 -0700
+++ 25-akpm/kernel/exit.c	2003-09-08 21:12:46.000000000 -0700
@@ -152,7 +152,7 @@ static int will_become_orphaned_pgrp(int
 				|| p->state >= TASK_ZOMBIE 
 				|| p->real_parent->pid == 1)
 			continue;
-		if (p->real_parent->pgrp != pgrp
+		if (process_group(p->real_parent) != pgrp
 			    && p->real_parent->session == p->session) {
 			ret = 0;
 			break;
@@ -247,9 +247,9 @@ void __set_special_pids(pid_t session, p
 		curr->session = session;
 		attach_pid(curr, PIDTYPE_SID, session);
 	}
-	if (curr->pgrp != pgrp) {
+	if (process_group(curr) != pgrp) {
 		detach_pid(curr, PIDTYPE_PGID);
-		curr->pgrp = pgrp;
+		curr->group_leader->__pgrp = pgrp;
 		attach_pid(curr, PIDTYPE_PGID, pgrp);
 	}
 }
@@ -508,9 +508,9 @@ static inline void reparent_thread(task_
 	 * than we are, and it was the only connection
 	 * outside, so the child pgrp is now orphaned.
 	 */
-	if ((p->pgrp != father->pgrp) &&
+	if ((process_group(p) != process_group(father)) &&
 	    (p->session == father->session)) {
-		int pgrp = p->pgrp;
+		int pgrp = process_group(p);
 
 		if (will_become_orphaned_pgrp(pgrp, NULL) && has_stopped_jobs(pgrp)) {
 			__kill_pg_info(SIGHUP, (void *)1, pgrp);
@@ -618,12 +618,12 @@ static void exit_notify(struct task_stru
 	 
 	t = tsk->real_parent;
 	
-	if ((t->pgrp != tsk->pgrp) &&
+	if ((process_group(t) != process_group(tsk)) &&
 	    (t->session == tsk->session) &&
-	    will_become_orphaned_pgrp(tsk->pgrp, tsk) &&
-	    has_stopped_jobs(tsk->pgrp)) {
-		__kill_pg_info(SIGHUP, (void *)1, tsk->pgrp);
-		__kill_pg_info(SIGCONT, (void *)1, tsk->pgrp);
+	    will_become_orphaned_pgrp(process_group(tsk), tsk) &&
+	    has_stopped_jobs(process_group(tsk))) {
+		__kill_pg_info(SIGHUP, (void *)1, process_group(tsk));
+		__kill_pg_info(SIGCONT, (void *)1, process_group(tsk));
 	}
 
 	/* Let father know we died 
@@ -813,10 +813,10 @@ static int eligible_child(pid_t pid, int
 		if (p->pid != pid)
 			return 0;
 	} else if (!pid) {
-		if (p->pgrp != current->pgrp)
+		if (process_group(p) != process_group(current))
 			return 0;
 	} else if (pid != -1) {
-		if (p->pgrp != -pid)
+		if (process_group(p) != -pid)
 			return 0;
 	}
 
diff -puN kernel/pid.c~group_leader-rework kernel/pid.c
--- 25/kernel/pid.c~group_leader-rework	2003-09-08 21:12:46.000000000 -0700
+++ 25-akpm/kernel/pid.c	2003-09-08 21:12:46.000000000 -0700
@@ -250,13 +250,13 @@ void switch_exec_pids(task_t *leader, ta
 
 	attach_pid(thread, PIDTYPE_PID, thread->pid);
 	attach_pid(thread, PIDTYPE_TGID, thread->tgid);
-	attach_pid(thread, PIDTYPE_PGID, thread->pgrp);
+	attach_pid(thread, PIDTYPE_PGID, leader->__pgrp);
 	attach_pid(thread, PIDTYPE_SID, thread->session);
 	list_add_tail(&thread->tasks, &init_task.tasks);
 
 	attach_pid(leader, PIDTYPE_PID, leader->pid);
 	attach_pid(leader, PIDTYPE_TGID, leader->tgid);
-	attach_pid(leader, PIDTYPE_PGID, leader->pgrp);
+	attach_pid(leader, PIDTYPE_PGID, leader->__pgrp);
 	attach_pid(leader, PIDTYPE_SID, leader->session);
 }
 
diff -puN kernel/signal.c~group_leader-rework kernel/signal.c
--- 25/kernel/signal.c~group_leader-rework	2003-09-08 21:12:46.000000000 -0700
+++ 25-akpm/kernel/signal.c	2003-09-08 21:12:46.000000000 -0700
@@ -1139,7 +1139,7 @@ kill_proc_info(int sig, struct siginfo *
 static int kill_something_info(int sig, struct siginfo *info, int pid)
 {
 	if (!pid) {
-		return kill_pg_info(sig, info, current->pgrp);
+		return kill_pg_info(sig, info, process_group(current));
 	} else if (pid == -1) {
 		int retval = 0, count = 0;
 		struct task_struct * p;
@@ -1798,7 +1798,7 @@ relock:
 
 			/* signals can be posted during this window */
 
-			if (is_orphaned_pgrp(current->pgrp))
+			if (is_orphaned_pgrp(process_group(current)))
 				goto relock;
 
 			spin_lock_irq(&current->sighand->siglock);
diff -puN include/linux/sched.h~group_leader-rework include/linux/sched.h
--- 25/include/linux/sched.h~group_leader-rework	2003-09-08 21:12:46.000000000 -0700
+++ 25-akpm/include/linux/sched.h	2003-09-08 21:12:46.000000000 -0700
@@ -360,7 +360,7 @@ struct task_struct {
 	unsigned long personality;
 	int did_exec:1;
 	pid_t pid;
-	pid_t pgrp;
+	pid_t __pgrp;		/* Accessed via process_group() */
 	pid_t tty_old_pgrp;
 	pid_t session;
 	pid_t tgid;
@@ -461,6 +461,11 @@ struct task_struct {
 	siginfo_t *last_siginfo; /* For ptrace use.  */
 };
 
+static inline pid_t process_group(struct task_struct *tsk)
+{
+	return tsk->group_leader->__pgrp;
+}
+
 extern void __put_task_struct(struct task_struct *tsk);
 #define get_task_struct(tsk) do { atomic_inc(&(tsk)->usage); } while(0)
 #define put_task_struct(tsk) \
diff -puN kernel/fork.c~group_leader-rework kernel/fork.c
--- 25/kernel/fork.c~group_leader-rework	2003-09-08 21:12:46.000000000 -0700
+++ 25-akpm/kernel/fork.c	2003-09-08 21:12:46.000000000 -0700
@@ -1004,7 +1004,7 @@ struct task_struct *copy_process(unsigne
 	attach_pid(p, PIDTYPE_PID, p->pid);
 	if (thread_group_leader(p)) {
 		attach_pid(p, PIDTYPE_TGID, p->tgid);
-		attach_pid(p, PIDTYPE_PGID, p->pgrp);
+		attach_pid(p, PIDTYPE_PGID, process_group(p));
 		attach_pid(p, PIDTYPE_SID, p->session);
 		if (p->pid)
 			__get_cpu_var(process_counts)++;

_

Re: [PATCH] use group_leader->pgrp (was Re: setpgid and threads)

[Ulrich Drepper]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Andrew Morton wrote:

> OK.  There were a few missing ones.  Here's what I have, against test5.  Do
> you have a test suite which would give us reasonable confidence?

Nope, I don't.

Why not leave the element renamed for a test release or two.  So the
nice people who do compile checks on all the drivers will find the
missing changes.


> Should setpgrp() in a thread affect the group leader?   It does...

Yes.  This the existence of a thread group leader different from current
 means using the POSIX thread "process" semantics this is the case.  All
the thread together have only one "process group" ("process" again in
the POSIX sense).

- -- 
- --------------.                        ,-.            444 Castro Street
Ulrich Drepper \    ,-----------------'   \ Mountain View, CA 94041 USA
Red Hat         `--' drepper at redhat.com `---------------------------
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Version: GnuPG v1.2.1 (GNU/Linux)

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55qtBiGdqNyl6sAwR6OCPXg=
=5oJh
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Re: [PATCH] use group_leader->pgrp (was Re: setpgid and threads)

[Jeremy Fitzhardinge]

On Mon, 2003-09-08 at 21:17, Andrew Morton wrote:
> All other instances of foo->pgrp have been converted to process_group(foo),
> which is foo->group_leader->__pgrp.
> 
> Should setpgrp() in a thread affect the group leader?   It does...

Eh?  sys_setpgid() fails with EINVAL if another thread tries to change
the process group.  Oh, I see.  setpgrp() is a wrapper which passes
pid=0 to setpgid; sys_setpgid uses current->pid rather than
current->tgid, so it always uses the thread group leader's ID.  Looks OK
to me.

	J

Re: [PATCH] use group_leader->pgrp (was Re: setpgid and threads)

[Roland McGrath]

> Would it make sense to do this via
> 
> 	if (is_orphaned_pgrp(process_group(current)))
> 
> and to then rename task_struct.pgrp to something else, to pick up any
> missed conversions?

I am wholly in favor of this.  I think what we really want to do is move
pgrp into signal_struct, and that would be painless after the macroization. 


Thanks,
Roland