linux/fs/proc
Alexey Dobriyan c2c0bb4462 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>
2015-06-25 17:00:37 -07:00
..
array.c procfs: treat parked tasks as sleeping for task state 2015-06-24 17:49:40 -07:00
base.c proc: fix PAGE_SIZE limit of /proc/$PID/cmdline 2015-06-25 17:00:37 -07:00
cmdline.c fs/proc: don't use module_init for non-modular core code 2014-01-23 16:37:02 -08:00
consoles.c fs/proc: don't use module_init for non-modular core code 2014-01-23 16:37:02 -08:00
cpuinfo.c fs/proc: don't use module_init for non-modular core code 2014-01-23 16:37:02 -08:00
devices.c fs/proc: don't use module_init for non-modular core code 2014-01-23 16:37:02 -08:00
fd.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2015-04-26 17:22:07 -07:00
fd.h proc: Move proc_fd() to fs/proc/fd.h 2013-05-01 17:29:39 -04:00
generic.c VFS: normal filesystems (and lustre): d_inode() annotations 2015-04-15 15:06:57 -04:00
inode.c switch ->put_link() from dentry to inode 2015-05-11 08:13:12 -04:00
internal.h procfs: fix race between symlink removals and traversals 2015-02-22 11:43:12 -05:00
interrupts.c fs/proc: don't use module_init for non-modular core code 2014-01-23 16:37:02 -08:00
Kconfig kcore: add Kconfig help text 2013-11-13 12:09:33 +09:00
kcore.c fs/proc/kcore.c: don't add modules range to kcore if it's equal to vmcore range 2014-10-09 22:25:50 -04:00
kmsg.c fs/proc: don't use module_init for non-modular core code 2014-01-23 16:37:02 -08:00
loadavg.c fs/proc: don't use module_init for non-modular core code 2014-01-23 16:37:02 -08:00
Makefile proc: Implement /proc/thread-self to point at the directory of the current thread 2014-08-04 10:07:11 -07:00
meminfo.c fs/proc/meminfo.c: include cma info in proc/meminfo 2014-12-18 19:08:10 -08:00
namespaces.c don't pass nameidata to ->follow_link() 2015-05-10 22:20:15 -04:00
nommu.c fs/proc: don't use module_init for non-modular core code 2014-01-23 16:37:02 -08:00
page.c mm:add KPF_ZERO_PAGE flag for /proc/kpageflags 2015-02-11 17:06:00 -08:00
proc_net.c VFS: normal filesystems (and lustre): d_inode() annotations 2015-04-15 15:06:57 -04:00
proc_sysctl.c VFS: normal filesystems (and lustre): d_inode() annotations 2015-04-15 15:06:57 -04:00
proc_tty.c proc: remove proc_tty_ldisc variable 2014-08-08 15:57:22 -07:00
root.c VFS: normal filesystems (and lustre): d_inode() annotations 2015-04-15 15:06:57 -04:00
self.c don't pass nameidata to ->follow_link() 2015-05-10 22:20:15 -04:00
softirqs.c fs/proc: don't use module_init for non-modular core code 2014-01-23 16:37:02 -08:00
stat.c genirq: Prevent proc race against freeing of irq descriptors 2014-12-13 13:33:07 +01:00
task_mmu.c pagemap: do not leak physical addresses to non-privileged userspace 2015-03-17 09:31:30 -07:00
task_nommu.c proc/maps: make vm_is_stack() logic namespace-friendly 2014-10-09 22:25:50 -04:00
thread_self.c don't pass nameidata to ->follow_link() 2015-05-10 22:20:15 -04:00
uptime.c cputime: Default implementation of nsecs -> cputime conversion 2014-03-13 15:56:43 +01:00
version.c fs/proc: don't use module_init for non-modular core code 2014-01-23 16:37:02 -08:00
vmcore.c vmcore: fix PT_NOTE n_namesz, n_descsz overflow issue 2015-02-17 14:34:52 -08:00