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| author | Al Viro <viro@zeniv.linux.org.uk> | 2012-08-21 22:32:06 -0400 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2012-09-26 21:09:59 -0400 |
| commit | c3c073f808b22dfae15ef8412b6f7b998644139a (patch) | |
| tree | 3369bcbe414738d90e6ccfe257f6ce3e72f6a5ae /drivers/tty | |
| parent | ad47bd7252bf402fe7dba92f5240b5ed16832ae7 (diff) | |
| download | linux-c3c073f808b22dfae15ef8412b6f7b998644139a.tar.gz linux-c3c073f808b22dfae15ef8412b6f7b998644139a.tar.bz2 linux-c3c073f808b22dfae15ef8412b6f7b998644139a.zip | |
new helper: iterate_fd()
iterates through the opened files in given descriptor table,
calling a supplied function; we stop once non-zero is returned.
Callback gets struct file *, descriptor number and const void *
argument passed to iterator. It is called with files->file_lock
held, so it is not allowed to block.
tty_io, netprio_cgroup and selinux flush_unauthorized_files()
converted to its use.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'drivers/tty')
| -rw-r--r-- | drivers/tty/tty_io.c | 36 |
1 files changed, 13 insertions, 23 deletions
diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c index b425c79675ad..71d95cfbabec 100644 --- a/drivers/tty/tty_io.c +++ b/drivers/tty/tty_io.c @@ -2791,6 +2791,13 @@ static long tty_compat_ioctl(struct file *file, unsigned int cmd, } #endif +static int this_tty(const void *t, struct file *file, unsigned fd) +{ + if (likely(file->f_op->read != tty_read)) + return 0; + return file_tty(file) != t ? 0 : fd + 1; +} + /* * This implements the "Secure Attention Key" --- the idea is to * prevent trojan horses by killing all processes associated with this @@ -2818,8 +2825,6 @@ void __do_SAK(struct tty_struct *tty) struct task_struct *g, *p; struct pid *session; int i; - struct file *filp; - struct fdtable *fdt; if (!tty) return; @@ -2849,27 +2854,12 @@ void __do_SAK(struct tty_struct *tty) continue; } task_lock(p); - if (p->files) { - /* - * We don't take a ref to the file, so we must - * hold ->file_lock instead. - */ - spin_lock(&p->files->file_lock); - fdt = files_fdtable(p->files); - for (i = 0; i < fdt->max_fds; i++) { - filp = fcheck_files(p->files, i); - if (!filp) - continue; - if (filp->f_op->read == tty_read && - file_tty(filp) == tty) { - printk(KERN_NOTICE "SAK: killed process %d" - " (%s): fd#%d opened to the tty\n", - task_pid_nr(p), p->comm, i); - force_sig(SIGKILL, p); - break; - } - } - spin_unlock(&p->files->file_lock); + i = iterate_fd(p->files, 0, this_tty, tty); + if (i != 0) { + printk(KERN_NOTICE "SAK: killed process %d" + " (%s): fd#%d opened to the tty\n", + task_pid_nr(p), p->comm, i - 1); + force_sig(SIGKILL, p); } task_unlock(p); } while_each_thread(g, p); |