From 9a2e70572e94e21e7ec4186702d045415422bda0 Mon Sep 17 00:00:00 2001 From: Pavel Emelyanov Date: Thu, 18 Oct 2007 23:40:39 -0700 Subject: [PATCH] Isolate the explicit usage of signal->pgrp The pgrp field is not used widely around the kernel so it is now marked as deprecated with appropriate comment. The initialization of INIT_SIGNALS is trimmed because a) they are set to 0 automatically; b) gcc cannot properly initialize two anonymous (the second one is the one with the session) unions. In this particular case to make it compile we'd have to add some field initialized right before the .pgrp. This is the same patch as the 1ec320afdc9552c92191d5f89fcd1ebe588334ca one (from Cedric), but for the pgrp field. Some progress report: We have to deprecate the pid, tgid, session and pgrp fields on struct task_struct and struct signal_struct. The session and pgrp are already deprecated. The tgid value is close to being such - the worst known usage in in fs/locks.c and audit code. The pid field deprecation is mainly blocked by numerous printk-s around the kernel that print the tsk->pid to log. Signed-off-by: Pavel Emelyanov Cc: Oleg Nesterov Cc: Sukadev Bhattiprolu Cc: Cedric Le Goater Cc: Serge Hallyn Cc: "Eric W. Biederman" Cc: Herbert Poetzl Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/init_task.h | 3 --- include/linux/sched.h | 19 +++++++++++++++++-- kernel/exit.c | 2 +- kernel/fork.c | 4 ++-- kernel/sys.c | 2 +- 5 files changed, 21 insertions(+), 9 deletions(-) diff --git a/include/linux/init_task.h b/include/linux/init_task.h index 5ac5945696..cae35b6b9a 100644 --- a/include/linux/init_task.h +++ b/include/linux/init_task.h @@ -67,9 +67,6 @@ .posix_timers = LIST_HEAD_INIT(sig.posix_timers), \ .cpu_timers = INIT_CPU_TIMERS(sig.cpu_timers), \ .rlim = INIT_RLIMITS, \ - .pgrp = 0, \ - .tty_old_pgrp = NULL, \ - { .__session = 0}, \ } extern struct nsproxy init_nsproxy; diff --git a/include/linux/sched.h b/include/linux/sched.h index 4bbbe12880..13df99fb27 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -429,7 +429,17 @@ struct signal_struct { cputime_t it_prof_incr, it_virt_incr; /* job control IDs */ - pid_t pgrp; + + /* + * pgrp and session fields are deprecated. + * use the task_session_Xnr and task_pgrp_Xnr routines below + */ + + union { + pid_t pgrp __deprecated; + pid_t __pgrp; + }; + struct pid *tty_old_pgrp; union { @@ -1196,6 +1206,11 @@ static inline void set_task_session(struct task_struct *tsk, pid_t session) tsk->signal->__session = session; } +static inline void set_task_pgrp(struct task_struct *tsk, pid_t pgrp) +{ + tsk->signal->__pgrp = pgrp; +} + static inline struct pid *task_pid(struct task_struct *task) { return task->pids[PIDTYPE_PID].pid; @@ -1268,7 +1283,7 @@ static inline pid_t task_tgid_vnr(struct task_struct *tsk) static inline pid_t task_pgrp_nr(struct task_struct *tsk) { - return tsk->signal->pgrp; + return tsk->signal->__pgrp; } pid_t task_pgrp_nr_ns(struct task_struct *tsk, struct pid_namespace *ns); diff --git a/kernel/exit.c b/kernel/exit.c index 68d27039ef..6838d4d77e 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -306,7 +306,7 @@ void __set_special_pids(pid_t session, pid_t pgrp) } if (task_pgrp_nr(curr) != pgrp) { detach_pid(curr, PIDTYPE_PGID); - curr->signal->pgrp = pgrp; + set_task_pgrp(curr, pgrp); attach_pid(curr, PIDTYPE_PGID, find_pid(pgrp)); } } diff --git a/kernel/fork.c b/kernel/fork.c index 240aa6601f..9d40367dd5 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -1293,13 +1293,13 @@ static struct task_struct *copy_process(unsigned long clone_flags, if (clone_flags & CLONE_NEWPID) { p->nsproxy->pid_ns->child_reaper = p; p->signal->tty = NULL; - p->signal->pgrp = p->pid; + set_task_pgrp(p, p->pid); set_task_session(p, p->pid); attach_pid(p, PIDTYPE_PGID, pid); attach_pid(p, PIDTYPE_SID, pid); } else { p->signal->tty = current->signal->tty; - p->signal->pgrp = task_pgrp_nr(current); + set_task_pgrp(p, task_pgrp_nr(current)); set_task_session(p, task_session_nr(current)); attach_pid(p, PIDTYPE_PGID, task_pgrp(current)); diff --git a/kernel/sys.c b/kernel/sys.c index 2befc29912..304b5410d7 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -977,7 +977,7 @@ asmlinkage long sys_setpgid(pid_t pid, pid_t pgid) detach_pid(p, PIDTYPE_PGID); pid = find_vpid(pgid); attach_pid(p, PIDTYPE_PGID, pid); - p->signal->pgrp = pid_nr(pid); + set_task_pgrp(p, pid_nr(pid)); } err = 0; -- 2.39.5