Skip to content

K
Kernel

openeuler / Kernel
1 年多 前同步成功

通知 8
Star 0
Fork 0
K
Kernel
切换分支/标签
  1. 02 10月, 2006 7 次提交
    • E
      [PATCH] proc: reorder the functions in base.c · 28a6d671
      由 Eric W. Biederman 提交于 
      There were enough changes in my last round of cleaning up proc I had to break
up the patch series into smaller chunks, and my last chunk never got resent.

This patchset gives proc dynamic inode numbers (the static inode numbers were
a pain to maintain and prevent all kinds of things), and removes the horrible
switch statements that had to be kept in sync with everything else.  Being
fully table driver takes us 90% of the way of being able to register new
process specific attributes in proc.

This patch:

Group the functions by what they implement instead of by type of operation.
As it existed base.c was quickly approaching the point where it could not be
followed.

No functionality or code changes asside from adding/removing forward
declartions are implemented in this patch.
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>
      28a6d671
    • E
      [PATCH] proc: readdir race fix (take 3) · 0804ef4b
      由 Eric W. Biederman 提交于 
      The problem: An opendir, readdir, closedir sequence can fail to report
process ids that are continually in use throughout the sequence of system
calls.  For this race to trigger the process that proc_pid_readdir stops at
must exit before readdir is called again.

This can cause ps to fail to report processes, and it is in violation of
posix guarantees and normal application expectations with respect to
readdir.

Currently there is no way to work around this problem in user space short
of providing a gargantuan buffer to user space so the directory read all
happens in on system call.

This patch implements the normal directory semantics for proc, that
guarantee that a directory entry that is neither created nor destroyed
while reading the directory entry will be returned.  For directory that are
either created or destroyed during the readdir you may or may not see them.
 Furthermore you may seek to a directory offset you have previously seen.

These are the guarantee that ext[23] provides and that posix requires, and
more importantly that user space expects.  Plus it is a simple semantic to
implement reliable service.  It is just a matter of calling readdir a
second time if you are wondering if something new has show up.

These better semantics are implemented by scanning through the pids in
numerical order and by making the file offset a pid plus a fixed offset.

The pid scan happens on the pid bitmap, which when you look at it is
remarkably efficient for a brute force algorithm.  Given that a typical
cache line is 64 bytes and thus covers space for 64*8 == 200 pids.  There
are only 40 cache lines for the entire 32K pid space.  A typical system
will have 100 pids or more so this is actually fewer cache lines we have to
look at to scan a linked list, and the worst case of having to scan the
entire pid bitmap is pretty reasonable.

If we need something more efficient we can go to a more efficient data
structure for indexing the pids, but for now what we have should be
sufficient.

In addition this takes no additional locks and is actually less code than
what we are doing now.

Also another very subtle bug in this area has been fixed.  It is possible
to catch a task in the middle of de_thread where a thread is assuming the
thread of it's thread group leader.  This patch carefully handles that case
so if we hit it we don't fail to return the pid, that is undergoing the
de_thread dance.

Thanks to KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> for
providing the first fix, pointing this out and working on it.

[oleg@tv-sign.ru: fix it]
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Acked-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: NOleg Nesterov <oleg@tv-sign.ru>
Cc: Jean Delvare <jdelvare@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      0804ef4b
    • R
      [PATCH] list module taint flags in Oops/panic · 2bc2d61a
      由 Randy Dunlap 提交于 
      When listing loaded modules during an oops or panic, also list each
module's Tainted flags if non-zero (P: Proprietary or F: Forced load only).

If a module is did not taint the kernel, it is just listed like
	usbcore
but if it did taint the kernel, it is listed like
	wizmodem(PF)

Example:
[ 3260.121718] Unable to handle kernel NULL pointer dereference at 0000000000000000 RIP:
[ 3260.121729]  [<ffffffff8804c099>] :dump_test:proc_dump_test+0x99/0xc8
[ 3260.121742] PGD fe8d067 PUD 264a6067 PMD 0
[ 3260.121748] Oops: 0002 [1] SMP
[ 3260.121753] CPU 1
[ 3260.121756] Modules linked in: dump_test(P) snd_pcm_oss snd_mixer_oss snd_seq snd_seq_device ide_cd generic ohci1394 snd_hda_intel snd_hda_codec snd_pcm snd_timer snd ieee1394 snd_page_alloc piix ide_core arcmsr aic79xx scsi_transport_spi usblp
[ 3260.121785] Pid: 5556, comm: bash Tainted: P      2.6.18-git10 #1

[Alternatively, I can look into listing tainted flags with 'lsmod',
but that won't help in oopsen/panics so much.]

[akpm@osdl.org: cleanup]
Signed-off-by: NRandy Dunlap <rdunlap@xenotime.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      2bc2d61a
    • D
      [PATCH] make genpool allocator adhere to kernel-doc standards · a58cbd7c
      由 Dean Nelson 提交于 
      The exported kernel interfaces of genpool allocator need to adhere to
the requirements of kernel-doc.
Signed-off-by: NDean Nelson <dcn@sgi.com>
Cc: Steve Wise <swise@opengridcomputing.com>
Acked-by: NRandy Dunlap <rdunlap@xenotime.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      a58cbd7c
    • S
      [PATCH] LIB: add gen_pool_destroy() · 322acc96
      由 Steve Wise 提交于 
      Modules using the genpool allocator need to be able to destroy the data
structure when unloading.
Signed-off-by: NSteve Wise <swise@opengridcomputing.com>
Cc: Randy Dunlap <rdunlap@xenotime.net>
Cc: Dean Nelson <dcn@sgi.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      322acc96
    • L
      pccard_store_cis: fix wrong error handling · d834c165
      由 Linus Torvalds 提交于 
      The test for the error from pcmcia_replace_cis() was incorrect, and
would always trigger (because if an error didn't happen, the "ret" value
would not be zero, it would be the passed-in count).

Reported and debugged by Fabrice Bellet <fabrice@bellet.info>

Rather than just fix the single broken test, make the code in question
use an understandable code-sequence instead, fixing the whole function
to be more readable.
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      d834c165
    • A
      [PATCH] rtc-sysfs fix · 4e9011d5
      由 Andrew Morton 提交于 
      It's not clear how this thinko got through..

Cc: Olaf Hering <olaf@aepfle.de>
Cc: David Brownell <david-b@pacbell.net>
Cc: Alessandro Zummo <alessandro.zummo@towertech.it>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      4e9011d5
  3. 01 10月, 2006 33 次提交