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author | Alexey Dobriyan <adobriyan@gmail.com> | 2015-06-26 01:00:54 +0300 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2015-06-26 03:00:37 +0300 |
commit | c2c0bb44620dece7ec97e28167e32c343da22867 (patch) | |
tree | b5241c0292ac868eec2c5589cdbffed224fd09b0 /init | |
parent | 4a00e9df293d010acbea118b9521e08cb85016c6 (diff) | |
download | linux-c2c0bb44620dece7ec97e28167e32c343da22867.tar.xz |
proc: fix PAGE_SIZE limit of /proc/$PID/cmdline
/proc/$PID/cmdline truncates output at PAGE_SIZE. It is easy to see with
$ cat /proc/self/cmdline $(seq 1037) 2>/dev/null
However, command line size was never limited to PAGE_SIZE but to 128 KB
and relatively recently limitation was removed altogether.
People noticed and ask questions:
http://stackoverflow.com/questions/199130/how-do-i-increase-the-proc-pid-cmdline-4096-byte-limit
seq file interface is not OK, because it kmalloc's for whole output and
open + read(, 1) + sleep will pin arbitrary amounts of kernel memory. To
not do that, limit must be imposed which is incompatible with arbitrary
sized command lines.
I apologize for hairy code, but this it direct consequence of command line
layout in memory and hacks to support things like "init [3]".
The loops are "unrolled" otherwise it is either macros which hide control
flow or functions with 7-8 arguments with equal line count.
There should be real setproctitle(2) or something.
[akpm@linux-foundation.org: fix a billion min() warnings]
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Tested-by: Jarod Wilson <jarod@redhat.com>
Acked-by: Jarod Wilson <jarod@redhat.com>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Jan Stancek <jstancek@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'init')
0 files changed, 0 insertions, 0 deletions