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Linus Torvalds 5ab8271899 fs/proc: simplify and clarify get_mm_cmdline() function
We have some very odd semantics for reading the command line through
/proc, because we allow people to rewrite their own command line pretty
much at will, and things get positively funky when you extend your
command line past the point that used to be the end of the command line,
and is now in the environment variable area.

But our weird semantics doesn't mean that we should write weird and
complex code to handle them.

So re-write get_mm_cmdline() to be much simpler, and much more explicit
about what it is actually doing and why.  And avoid the extra check for
"is there a NUL character at the end of the command line where I expect
one to be", by simply making the NUL character handling be part of the
normal "once you hit the end of the command line, stop at the first NUL
character" logic.

It's quite possible that we should stop the crazy "walk into
environment" entirely, but happily it's not really the usual case.

NOTE! We tried to really simplify and limit our odd cmdline parsing some
time ago, but people complained.  See commit c2c0bb4462 ("proc: fix
PAGE_SIZE limit of /proc/$PID/cmdline") for details about why we have
this complexity.

Cc: Tejun Heo <tj@kernel.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Jarod Wilson <jarod@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-05-17 15:35:02 -07:00
Documentation * ARM/ARM64 locking fixes 2018-05-17 10:23:36 -07:00
LICENSES LICENSES: Add MPL-1.1 license 2018-01-06 10:59:44 -07:00
arch * ARM/ARM64 locking fixes 2018-05-17 10:23:36 -07:00
block blk-mq: fix sysfs inflight counter 2018-04-26 09:02:01 -06:00
certs certs/blacklist_nohashes.c: fix const confusion in certs blacklist 2018-02-21 15:35:43 -08:00
crypto crypto: drbg - set freed buffers to NULL 2018-04-21 00:57:00 +08:00
drivers Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux 2018-05-17 10:11:44 -07:00
firmware kbuild: remove all dummy assignments to obj- 2017-11-18 11:46:06 +09:00
fs fs/proc: simplify and clarify get_mm_cmdline() function 2018-05-17 15:35:02 -07:00
include * ARM/ARM64 locking fixes 2018-05-17 10:23:36 -07:00
init init: fix false positives in W+X checking 2018-05-11 17:28:45 -07:00
ipc ipc/shm: fix use-after-free of shm file via remap_file_pages() 2018-04-13 17:10:27 -07:00
kernel Merge branch 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-05-13 10:53:08 -07:00
lib vsprintf: Replace memory barrier with static_key for random_ptr_key update 2018-05-16 09:01:41 -04:00
mm proc: do not access cmdline nor environ from file-backed areas 2018-05-17 09:27:47 -07:00
net Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-05-11 14:14:46 -07:00
samples bpf: sockmap sample use clang flag, -target bpf 2018-04-23 23:42:21 +02:00
scripts scripts/faddr2line: fix error when addr2line output contains discriminator 2018-05-11 17:28:45 -07:00
security selinux/stable-4.17 PR 20180516 2018-05-17 10:02:19 -07:00
sound ALSA: usb-audio: Use Class Specific EP for UAC3 devices. 2018-05-15 07:29:10 +02:00
tools * ARM/ARM64 locking fixes 2018-05-17 10:23:36 -07:00
usr kbuild: rename built-in.o to built-in.a 2018-03-26 02:01:19 +09:00
virt KVM: arm/arm64: VGIC/ITS save/restore: protect kvm_read_guest() calls 2018-05-15 13:36:53 +02:00
.clang-format clang-format: add configuration file 2018-04-11 10:28:35 -07:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore
.gitattributes .gitattributes: set git diff driver for C source code files 2016-10-07 18:46:30 -07:00
.gitignore Kbuild updates for v4.17 (2nd) 2018-04-15 17:21:30 -07:00
.mailmap Merge candidates for 4.17 merge window 2018-04-06 17:35:43 -07:00
COPYING COPYING: use the new text with points to the license files 2018-03-23 12:41:45 -06:00
CREDITS MAINTAINERS/CREDITS: Drop METAG ARCHITECTURE 2018-03-05 16:34:24 +00:00
Kbuild Kbuild updates for v4.15 2017-11-17 17:45:29 -08:00
Kconfig License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
MAINTAINERS Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux 2018-05-17 10:11:44 -07:00
Makefile Linux 4.17-rc5 2018-05-13 16:15:17 -07:00
README Docs: Added a pointer to the formatted docs to README 2018-03-21 09:02:53 -06:00

README

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
See Documentation/00-INDEX for a list of what is contained in each file.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.