The patch titled
tty: simplify calling of put_pid.
has been added to the -mm tree. Its filename is
tty-simplify-calling-of-put_pid.patch
*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: tty: simplify calling of put_pid.
From: Eric W. Biederman <ebiederm@xxxxxxxxxxxx>
This patch should contain no functional changes.
At some point I got confused and thought put_pid could not be called while a
spin lock was held. While it may be nice to avoid that to reduce lock hold
times put_pid can be safely called while we hold a spin lock.
This patch removes all of the complications from the code introduced by my
misunderstanding, making the code a little more readable.
Signed-off-by: Eric W. Biederman <ebiederm@xxxxxxxxxxxx>
Cc: Alan Cox <alan@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
drivers/char/tty_io.c | 23 ++++++-----------------
1 file changed, 6 insertions(+), 17 deletions(-)
diff -puN drivers/char/tty_io.c~tty-simplify-calling-of-put_pid drivers/char/tty_io.c
--- a/drivers/char/tty_io.c~tty-simplify-calling-of-put_pid
+++ a/drivers/char/tty_io.c
@@ -153,8 +153,7 @@ int tty_ioctl(struct inode * inode, stru
unsigned int cmd, unsigned long arg);
static int tty_fasync(int fd, struct file * filp, int on);
static void release_tty(struct tty_struct *tty, int idx);
-static struct pid *__proc_set_tty(struct task_struct *tsk,
- struct tty_struct *tty);
+static void __proc_set_tty(struct task_struct *tsk, struct tty_struct *tty);
/**
* alloc_tty_struct - allocate a tty object
@@ -1532,10 +1531,9 @@ void disassociate_ctty(int on_exit)
}
spin_lock_irq(¤t->sighand->siglock);
- tty_pgrp = current->signal->tty_old_pgrp;
+ put_pid(current->signal->tty_old_pgrp);
current->signal->tty_old_pgrp = NULL;
spin_unlock_irq(¤t->sighand->siglock);
- put_pid(tty_pgrp);
mutex_lock(&tty_mutex);
/* It is possible that do_tty_hangup has free'd this tty */
@@ -2506,7 +2504,6 @@ static int tty_open(struct inode * inode
int index;
dev_t device = inode->i_rdev;
unsigned short saved_flags = filp->f_flags;
- struct pid *old_pgrp;
nonseekable_open(inode, filp);
@@ -2600,17 +2597,15 @@ got_driver:
goto retry_open;
}
- old_pgrp = NULL;
mutex_lock(&tty_mutex);
spin_lock_irq(¤t->sighand->siglock);
if (!noctty &&
current->signal->leader &&
!current->signal->tty &&
tty->session == NULL)
- old_pgrp = __proc_set_tty(current, tty);
+ __proc_set_tty(current, tty);
spin_unlock_irq(¤t->sighand->siglock);
mutex_unlock(&tty_mutex);
- put_pid(old_pgrp);
return 0;
}
@@ -3836,9 +3831,8 @@ void proc_clear_tty(struct task_struct *
spin_unlock_irq(&p->sighand->siglock);
}
-static struct pid *__proc_set_tty(struct task_struct *tsk, struct tty_struct *tty)
+static void __proc_set_tty(struct task_struct *tsk, struct tty_struct *tty)
{
- struct pid *old_pgrp;
if (tty) {
/* We should not have a session or pgrp to here but.... */
put_pid(tty->session);
@@ -3846,21 +3840,16 @@ static struct pid *__proc_set_tty(struct
tty->session = get_pid(task_session(tsk));
tty->pgrp = get_pid(task_pgrp(tsk));
}
- old_pgrp = tsk->signal->tty_old_pgrp;
+ put_pid(tsk->signal->tty_old_pgrp);
tsk->signal->tty = tty;
tsk->signal->tty_old_pgrp = NULL;
- return old_pgrp;
}
void proc_set_tty(struct task_struct *tsk, struct tty_struct *tty)
{
- struct pid *old_pgrp;
-
spin_lock_irq(&tsk->sighand->siglock);
- old_pgrp = __proc_set_tty(tsk, tty);
+ __proc_set_tty(tsk, tty);
spin_unlock_irq(&tsk->sighand->siglock);
-
- put_pid(old_pgrp);
}
struct tty_struct *get_current_tty(void)
_
Patches currently in -mm which might be from ebiederm@xxxxxxxxxxxx are
origin.patch
powerpc-rtas-msi-support.patch
fix-i-oat-for-kexec.patch
i386-irq-kill-irq-compression.patch
x86_64-irq-remove-extra-smp_processor_id-calling.patch
remove-hardcoding-of-hard_smp_processor_id-on-up.patch
use-the-apic-to-determine-the-hardware-processor-id-i386.patch
use-the-apic-to-determine-the-hardware-processor-id-x86_64.patch
always-ask-the-hardware-to-obtain-hardware-processor.patch
allow-i386-crash-kernels-to-handle-x86_64-dumps.patch
allow-i386-crash-kernels-to-handle-x86_64-dumps-fix.patch
clone-flag-clone_parent_tidptr-leaves-invalid-results-in-memory.patch
allow-access-to-proc-pid-fd-after-setuid.patch
merge-sys_clone-sys_unshare-nsproxy-and-namespace.patch
fix-race-between-proc_get_inode-and-remove_proc_entry.patch
fix-race-between-proc_readdir-and-remove_proc_entry.patch
procfs-reorder-struct-pid_dentry-to-save-space-on-64bit-archs-and-constify-them.patch
tty-fix-two-reported-pid-leaks.patch
tty-remove-unnecessary-export-of-proc_clear_tty.patch
tty-simplify-calling-of-put_pid.patch
tty-introduce-no_tty-and-use-it-in-selinux.patch
tty-in-tiocsctty-when-we-steal-a-tty-hang-it-up.patch
edac-k8-driver-coding-tidy.patch
statically-initialize-struct-pid-for-swapper.patch
explicitly-set-pgid-and-sid-of-init-process.patch
use-struct-pid-parameter-in-copy_process.patch
remove-the-likelypid-check-in-copy_process.patch
use-task_pgrp-task_session-in-copy_process.patch
kill-unused-sesssion-and-group-values-in-rocket-driver.patch
fix-some-coding-style-errors-in-autofs.patch
replace-pid_t-in-autofs-with-struct-pid-reference.patch
vdso-print-fatal-signals-use-ctl_unnumbered.patch
-
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
