提交 · 9ec52099e4b8678a60e9f93e41ad87885d64f3e6 · openeuler / Kernel

02 10月, 2006 40 次提交

[PATCH] replace cad_pid by a struct pid · 9ec52099

由 Cedric Le Goater 提交于 10月 02, 2006

There are a few places in the kernel where the init task is signaled.  The
ctrl+alt+del sequence is one them.  It kills a task, usually init, using a
cached pid (cad_pid).

This patch replaces the pid_t by a struct pid to avoid pid wrap around
problem.  The struct pid is initialized at boot time in init() and can be
modified through systctl with

	/proc/sys/kernel/cad_pid

[ I haven't found any distro using it ? ]

It also introduces a small helper routine kill_cad_pid() which is used
where it seemed ok to use cad_pid instead of pid 1.

[akpm@osdl.org: cleanups, build fix]
Signed-off-by: NCedric Le Goater <clg@fr.ibm.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

9ec52099

[PATCH] introduce get_task_pid() to fix unsafe get_pid() · 1a657f78

由 Oleg Nesterov 提交于 10月 02, 2006

proc_pid_make_inode:

	ei->pid = get_pid(task_pid(task));

I think this is not safe.  get_pid() can be preempted after checking "pid
!= NULL".  Then the task exits, does detach_pid(), and RCU frees the pid.
Signed-off-by: NOleg Nesterov <oleg@tv-sign.ru>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

1a657f78

[PATCH] proc: comment what proc_fill_cache does · 1c0d04c9

由 Eric W. Biederman 提交于 10月 02, 2006

Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

1c0d04c9

[PATCH] proc: remove the useless SMP-safe comments from /proc · 5e61feaf

由 Eric W. Biederman 提交于 10月 02, 2006

Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

5e61feaf

[PATCH] proc: remove trailing blank entry from pid_entry arrays · 7bcd6b0e

由 Eric W. Biederman 提交于 10月 02, 2006

It was pointed out that since I am taking ARRAY_SIZE anyway the trailing empty
entry is silly and just wastes space.
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

7bcd6b0e

[PATCH] proc: properly compute TGID_OFFSET · 8e95bd93

由 Eric W. Biederman 提交于 10月 02, 2006

The value doesn't change but this ensures I will have the proper value when
other files are added to proc_base_stuff.
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

8e95bd93

[PATCH] proc: drop tasklist lock in task_state() · b0fa9db6

由 Oleg Nesterov 提交于 10月 02, 2006

task_state() needs tasklist_lock to protect ->parent/->real_parent.  However
task->parent points to nowhere only when the actions below happen in order

	1) release_task(task)
	2) release_task(task->parent)
	3) a grace period passed

But 3) implies that the memory ops from 1) should be finished, so pid_alive()
can't be true in such a case.

Otherwise, we don't care if ->parent/->real_parent changes under us.
Signed-off-by: NOleg Nesterov <oleg@tv-sign.ru>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

b0fa9db6

[PATCH] proc: convert do_task_stat() to use lock_task_sighand() · a593d6ed

由 Oleg Nesterov 提交于 10月 02, 2006

Drop tasklist_lock. ->siglock protects almost all interesting data
(including sub-threads traversal) except:

	->signal->tty
		protected by tty_mutex

	->real_parent
		the task can't be unhashed while we are holding
		->siglock, so ->real_parent can change from under us
		but we can safely dereference it under rcu_read_lock()

	->pgrp/->session
		we can get inconsistent numbers if the task does
		sys_setsid/daemonize at the same time. I hope this
		is acceptable.
Signed-off-by: NOleg Nesterov <oleg@tv-sign.ru>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

a593d6ed

[PATCH] proc: convert task_sig() to use lock_task_sighand() · 5e6b3f42

由 Oleg Nesterov 提交于 10月 02, 2006

lock_task_sighand() can take ->siglock without holding tasklist_lock.
Signed-off-by: NOleg Nesterov <oleg@tv-sign.ru>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

5e6b3f42

[PATCH] proc: Use pid_task instead of open coding it · 7fbaac00

由 Eric W. Biederman 提交于 10月 02, 2006

Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

7fbaac00

[PATCH] proc: Merge proc_tid_attr and proc_tgid_attr · 72d9dcfc

由 Eric W. Biederman 提交于 10月 02, 2006

The implementation is exactly the same and there is currently nothing to
distinguish proc_tid_attr, and proc_tgid_attr.  So it is pointless to have two
separate implementations.
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

72d9dcfc

[PATCH] proc: Remove the hard coded inode numbers · 61a28784

由 Eric W. Biederman 提交于 10月 02, 2006

The hard coded inode numbers in proc currently limit its maintainability,
its flexibility, and what can be done with the rest of system.  /proc limits
pid-max to 32768 on 32 bit systems it limits fd-max to 32768 on all systems,
and placing the pid in the inode number really gets in the way of implementing
subdirectories of per process information.

Ever since people started adding to the middle of the file type enumeration we
haven't been maintaing the historical inode numbers, all we have really
succeeded in doing is keeping the pid in the proc inode number.  The pid is
already available in the directory name so no information is lost removing it
from the inode number.

So if something in user space cares if we remove the inode number from the
/proc inode it is almost certainly broken.
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

61a28784

[PATCH] proc: Factor out an instantiate method from every lookup method · 444ceed8

由 Eric W. Biederman 提交于 10月 02, 2006

To remove the hard coded proc inode numbers it is necessary to be able to
create the proc inodes during readdir.  The instantiate methods are the subset
of lookup that is needed to accomplish that.

This first step just splits the lookup methods into 2 functions.
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

444ceed8

[PATCH] proc: Make the generation of the self symlink table driven · 801199ce

由 Eric W. Biederman 提交于 10月 02, 2006

This patch generalizes the concept of files in /proc that are related to
processes but live in the root directory of /proc

Ideally this would reuse infrastructure from the rest of the process specific
parts of proc but unfortunately security_task_to_inode must not be called on
files that are not strictly per process. security_task_to_inode really needs
to be reexamined as the security label can change in important places that we
are not currently catching, but I'm not certain that simplifies this problem.

By at least matching the structure of the rest of proc we get more idiom reuse
and it becomes easier to spot problems in the way things are put together.

Later things like /proc/mounts are likely to be moved into proc_base as well.
If union mounts are ever supported we may be able to make /proc a union mount,
and properly split it into 2 filesystems.
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

801199ce

[PATCH] AVR32: Implement kernel_execve · c5f2420a

由 Haavard Skinnemoen 提交于 10月 02, 2006

Move execve() into arch/avr32/kernel/sys_avr32.c, rename it to
kernel_execve() and return the syscall return value directly without
setting errno.

This also gets rid of the __KERNEL_SYSCALLS__ stuff from unistd.h and
expands #ifdef __KERNEL__ to cover everything in unistd.h except the
__NR_foo definitions.
Signed-off-by: NHaavard Skinnemoen <hskinnemoen@atmel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

c5f2420a

[PATCH] remove remaining errno and __KERNEL_SYSCALLS__ references · 135ab6ec