linux/Documentation/sysctl, branch v2.6.39

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial

2011-03-18T17:37:40Z

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (47 commits) doc: CONFIG_UNEVICTABLE_LRU doesn't exist anymore Update cpuset info & webiste for cgroups dcdbas: force SMI to happen when expected arch/arm/Kconfig: remove one to many l's in the word. asm-generic/user.h: Fix spelling in comment drm: fix printk typo 'sracth' Remove one to many n's in a word Documentation/filesystems/romfs.txt: fixing link to genromfs drivers:scsi Change printk typo initate -> initiate serial, pch uart: Remove duplicate inclusion of linux/pci.h header fs/eventpoll.c: fix spelling mm: Fix out-of-date comments which refers non-existent functions drm: Fix printk typo 'failled' coh901318.c: Change initate to initiate. mbox-db5500.c Change initate to initiate. edac: correct i82975x error-info reported edac: correct i82975x mci initialisation edac: correct commented info fs: update comments to point correct document target: remove duplicate include of target/target_core_device.h from drivers/target/target_core_hba.c ... Trivial conflict in fs/eventpoll.c (spelling vs addition)

Documentation: file handles are now freed

2011-03-16T17:47:03Z

Since file handles are freed, a little amendment to the documentation Signed-off-by: Federica Teodori Acked-by: Rik van Riel Signed-off-by: Randy Dunlap Signed-off-by: Linus Torvalds

Documentation: default_message_level is a typo

2011-02-11T14:14:10Z

It's default_message_loglevel, not default_message_level. Signed-off-by: Paul Bolle Signed-off-by: Jiri Kosina

sysctl: remove obsolete comments

2011-01-13T16:03:18Z

ctl_unnumbered.txt have been removed in Documentation directory so just also remove this invalid comments [akpm@linux-foundation.org: fix Documentation/sysctl/00-INDEX, per Dave] Signed-off-by: Jovi Zhang Cc: Dave Young Acked-by: WANG Cong Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

kptr_restrict for hiding kernel pointers from unprivileged users

2011-01-13T16:03:08Z

Add the %pK printk format specifier and the /proc/sys/kernel/kptr_restrict sysctl. The %pK format specifier is designed to hide exposed kernel pointers, specifically via /proc interfaces. Exposing these pointers provides an easy target for kernel write vulnerabilities, since they reveal the locations of writable structures containing easily triggerable function pointers. The behavior of %pK depends on the kptr_restrict sysctl. If kptr_restrict is set to 0, no deviation from the standard %p behavior occurs. If kptr_restrict is set to 1, the default, if the current user (intended to be a reader via seq_printf(), etc.) does not have CAP_SYSLOG (currently in the LSM tree), kernel pointers using %pK are printed as 0's. If kptr_restrict is set to 2, kernel pointers using %pK are printed as 0's regardless of privileges. Replacing with 0's was chosen over the default "(null)", which cannot be parsed by userland %p, which expects "(nil)". [akpm@linux-foundation.org: check for IRQ context when !kptr_restrict, save an indent level, s/WARN/WARN_ONCE/] [akpm@linux-foundation.org: coding-style fixup] [randy.dunlap@oracle.com: fix kernel/sysctl.c warning] Signed-off-by: Dan Rosenberg Signed-off-by: Randy Dunlap Cc: James Morris Cc: Eric Dumazet Cc: Thomas Graf Cc: Eugene Teo Cc: Kees Cook Cc: Ingo Molnar Cc: David S. Miller Cc: Peter Zijlstra Cc: Eric Paris Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

syslog: check cap_syslog when dmesg_restrict

2010-12-08T22:48:48Z

Eric Paris pointed out that it doesn't make sense to require both CAP_SYS_ADMIN and CAP_SYSLOG for certain syslog actions. So require CAP_SYSLOG, not CAP_SYS_ADMIN, when dmesg_restrict is set. (I'm also consolidating the now common error path) Signed-off-by: Serge E. Hallyn Acked-by: Eric Paris Acked-by: Kees Cook Signed-off-by: James Morris

Restrict unprivileged access to kernel syslog

2010-11-12T15:55:32Z

The kernel syslog contains debugging information that is often useful during exploitation of other vulnerabilities, such as kernel heap addresses. Rather than futilely attempt to sanitize hundreds (or thousands) of printk statements and simultaneously cripple useful debugging functionality, it is far simpler to create an option that prevents unprivileged users from reading the syslog. This patch, loosely based on grsecurity's GRKERNSEC_DMESG, creates the dmesg_restrict sysctl. When set to "0", the default, no restrictions are enforced. When set to "1", only users with CAP_SYS_ADMIN can read the kernel syslog via dmesg(8) or other mechanisms. [akpm@linux-foundation.org: explain the config option in kernel.txt] Signed-off-by: Dan Rosenberg Acked-by: Ingo Molnar Acked-by: Eugene Teo Acked-by: Kees Cook Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

doc: clarify the behaviour of dirty_ratio/dirty_bytes

2010-10-28T01:03:08Z

When dirty_ratio or dirty_bytes is written the other parameter is disabled and set to 0 (in dirty_bytes_handler() / dirty_ratio_handler()). We do the same for dirty_background_ratio and dirty_background_bytes. However, in the sysctl documentation, we say that the counterpart becomes a function of the old value, that is not correct. Clarify the documentation reporting the actual behaviour. Reviewed-by: Greg Thelen Acked-by: David Rientjes Signed-off-by: Andrea Righi Cc: Randy Dunlap Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

oom: enable oom tasklist dump by default

2010-08-10T03:44:56Z

The oom killer tasklist dump, enabled with the oom_dump_tasks sysctl, is very helpful information in diagnosing why a user's task has been killed. It emits useful information such as each eligible thread's memory usage that can determine why the system is oom, so it should be enabled by default. Signed-off-by: David Rientjes Acked-by: KOSAKI Motohiro Cc: KAMEZAWA Hiroyuki Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Documentation/sysctl/vm.txt typo

2010-06-28T11:59:28Z

Fix trivial typo: duplicated word. Signed-off-by: Kulikov Vasiliy Acked-by: Randy Dunlap Signed-off-by: Jiri Kosina