summaryrefslogtreecommitdiff
path: root/kernel/sysctl.c
AgeCommit message (Collapse)Author
2012-08-01Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull second vfs pile from Al Viro: "The stuff in there: fsfreeze deadlock fixes by Jan (essentially, the deadlock reproduced by xfstests 068), symlink and hardlink restriction patches, plus assorted cleanups and fixes. Note that another fsfreeze deadlock (emergency thaw one) is *not* dealt with - the series by Fernando conflicts a lot with Jan's, breaks userland ABI (FIFREEZE semantics gets changed) and trades the deadlock for massive vfsmount leak; this is going to be handled next cycle. There probably will be another pull request, but that stuff won't be in it." Fix up trivial conflicts due to unrelated changes next to each other in drivers/{staging/gdm72xx/usb_boot.c, usb/gadget/storage_common.c} * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (54 commits) delousing target_core_file a bit Documentation: Correct s_umount state for freeze_fs/unfreeze_fs fs: Remove old freezing mechanism ext2: Implement freezing btrfs: Convert to new freezing mechanism nilfs2: Convert to new freezing mechanism ntfs: Convert to new freezing mechanism fuse: Convert to new freezing mechanism gfs2: Convert to new freezing mechanism ocfs2: Convert to new freezing mechanism xfs: Convert to new freezing code ext4: Convert to new freezing mechanism fs: Protect write paths by sb_start_write - sb_end_write fs: Skip atime update on frozen filesystem fs: Add freezing handling to mnt_want_write() / mnt_drop_write() fs: Improve filesystem freezing handling switch the protection of percpu_counter list to spinlock nfsd: Push mnt_want_write() outside of i_mutex btrfs: Push mnt_want_write() outside of i_mutex fat: Push mnt_want_write() outside of i_mutex ...
2012-07-31mm: prepare for removal of obsolete /proc/sys/vm/nr_pdflush_threadsWanpeng Li
Since per-BDI flusher threads were introduced in 2.6, the pdflush mechanism is not used any more. But the old interface exported through /proc/sys/vm/nr_pdflush_threads still exists and is obviously useless. For back-compatibility, printk warning information and return 2 to notify the users that the interface is removed. Signed-off-by: Wanpeng Li <liwp@linux.vnet.ibm.com> Cc: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-07-30sysctl: suppress kmemleak messagesSteven Rostedt
register_sysctl_table() is a strange function, as it makes internal allocations (a header) to register a sysctl_table. This header is a handle to the table that is created, and can be used to unregister the table. But if the table is permanent and never unregistered, the header acts the same as a static variable. Unfortunately, this allocation of memory that is never expected to be freed fools kmemleak in thinking that we have leaked memory. For those sysctl tables that are never unregistered, and have no pointer referencing them, kmemleak will think that these are memory leaks: unreferenced object 0xffff880079fb9d40 (size 192): comm "swapper/0", pid 0, jiffies 4294667316 (age 12614.152s) hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [<ffffffff8146b590>] kmemleak_alloc+0x73/0x98 [<ffffffff8110a935>] kmemleak_alloc_recursive.constprop.42+0x16/0x18 [<ffffffff8110b852>] __kmalloc+0x107/0x153 [<ffffffff8116fa72>] kzalloc.constprop.8+0xe/0x10 [<ffffffff811703c9>] __register_sysctl_paths+0xe1/0x160 [<ffffffff81170463>] register_sysctl_paths+0x1b/0x1d [<ffffffff8117047d>] register_sysctl_table+0x18/0x1a [<ffffffff81afb0a1>] sysctl_init+0x10/0x14 [<ffffffff81b05a6f>] proc_sys_init+0x2f/0x31 [<ffffffff81b0584c>] proc_root_init+0xa5/0xa7 [<ffffffff81ae5b7e>] start_kernel+0x3d0/0x40a [<ffffffff81ae52a7>] x86_64_start_reservations+0xae/0xb2 [<ffffffff81ae53ad>] x86_64_start_kernel+0x102/0x111 [<ffffffffffffffff>] 0xffffffffffffffff The sysctl_base_table used by sysctl itself is one such instance that registers the table to never be unregistered. Use kmemleak_not_leak() to suppress the kmemleak false positive. Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-07-30coredump: warn about unsafe suid_dumpable / core_pattern comboKees Cook
When suid_dumpable=2, detect unsafe core_pattern settings and warn when they are seen. Signed-off-by: Kees Cook <keescook@chromium.org> Suggested-by: Andrew Morton <akpm@linux-foundation.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Alan Cox <alan@linux.intel.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Doug Ledford <dledford@redhat.com> Cc: Serge Hallyn <serge.hallyn@canonical.com> Cc: James Morris <james.l.morris@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-07-29fs: add link restrictionsKees Cook
This adds symlink and hardlink restrictions to the Linux VFS. Symlinks: A long-standing class of security issues is the symlink-based time-of-check-time-of-use race, most commonly seen in world-writable directories like /tmp. The common method of exploitation of this flaw is to cross privilege boundaries when following a given symlink (i.e. a root process follows a symlink belonging to another user). For a likely incomplete list of hundreds of examples across the years, please see: http://cve.mitre.org/cgi-bin/cvekey.cgi?keyword=/tmp The solution is to permit symlinks to only be followed when outside a sticky world-writable directory, or when the uid of the symlink and follower match, or when the directory owner matches the symlink's owner. Some pointers to the history of earlier discussion that I could find: 1996 Aug, Zygo Blaxell http://marc.info/?l=bugtraq&m=87602167419830&w=2 1996 Oct, Andrew Tridgell http://lkml.indiana.edu/hypermail/linux/kernel/9610.2/0086.html 1997 Dec, Albert D Cahalan http://lkml.org/lkml/1997/12/16/4 2005 Feb, Lorenzo Hernández García-Hierro http://lkml.indiana.edu/hypermail/linux/kernel/0502.0/1896.html 2010 May, Kees Cook https://lkml.org/lkml/2010/5/30/144 Past objections and rebuttals could be summarized as: - Violates POSIX. - POSIX didn't consider this situation and it's not useful to follow a broken specification at the cost of security. - Might break unknown applications that use this feature. - Applications that break because of the change are easy to spot and fix. Applications that are vulnerable to symlink ToCToU by not having the change aren't. Additionally, no applications have yet been found that rely on this behavior. - Applications should just use mkstemp() or O_CREATE|O_EXCL. - True, but applications are not perfect, and new software is written all the time that makes these mistakes; blocking this flaw at the kernel is a single solution to the entire class of vulnerability. - This should live in the core VFS. - This should live in an LSM. (https://lkml.org/lkml/2010/5/31/135) - This should live in an LSM. - This should live in the core VFS. (https://lkml.org/lkml/2010/8/2/188) Hardlinks: On systems that have user-writable directories on the same partition as system files, a long-standing class of security issues is the hardlink-based time-of-check-time-of-use race, most commonly seen in world-writable directories like /tmp. The common method of exploitation of this flaw is to cross privilege boundaries when following a given hardlink (i.e. a root process follows a hardlink created by another user). Additionally, an issue exists where users can "pin" a potentially vulnerable setuid/setgid file so that an administrator will not actually upgrade a system fully. The solution is to permit hardlinks to only be created when the user is already the existing file's owner, or if they already have read/write access to the existing file. Many Linux users are surprised when they learn they can link to files they have no access to, so this change appears to follow the doctrine of "least surprise". Additionally, this change does not violate POSIX, which states "the implementation may require that the calling process has permission to access the existing file"[1]. This change is known to break some implementations of the "at" daemon, though the version used by Fedora and Ubuntu has been fixed[2] for a while. Otherwise, the change has been undisruptive while in use in Ubuntu for the last 1.5 years. [1] http://pubs.opengroup.org/onlinepubs/9699919799/functions/linkat.html [2] http://anonscm.debian.org/gitweb/?p=collab-maint/at.git;a=commitdiff;h=f4114656c3a6c6f6070e315ffdf940a49eda3279 This patch is based on the patches in Openwall and grsecurity, along with suggestions from Al Viro. I have added a sysctl to enable the protected behavior, and documentation. Signed-off-by: Kees Cook <keescook@chromium.org> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-04-05sysctl: fix write access to dmesg_restrict/kptr_restrictKees Cook
Commit bfdc0b4 adds code to restrict access to dmesg_restrict, however, it incorrectly alters kptr_restrict rather than dmesg_restrict. The original patch from Richard Weinberger (https://lkml.org/lkml/2011/3/14/362) alters dmesg_restrict as expected, and so the patch seems to have been misapplied. This adds the CAP_SYS_ADMIN check to both dmesg_restrict and kptr_restrict, since both are sensitive. Reported-by: Phillip Lougher <plougher@redhat.com> Signed-off-by: Kees Cook <keescook@chromium.org> Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Acked-by: Richard Weinberger <richard@nod.at> Cc: stable@vger.kernel.org Signed-off-by: James Morris <james.l.morris@oracle.com>
2012-03-28Merge branch 'akpm' (Andrew's patch-bomb)Linus Torvalds
Merge third batch of patches from Andrew Morton: - Some MM stragglers - core SMP library cleanups (on_each_cpu_mask) - Some IPI optimisations - kexec - kdump - IPMI - the radix-tree iterator work - various other misc bits. "That'll do for -rc1. I still have ~10 patches for 3.4, will send those along when they've baked a little more." * emailed from Andrew Morton <akpm@linux-foundation.org>: (35 commits) backlight: fix typo in tosa_lcd.c crc32: add help text for the algorithm select option mm: move hugepage test examples to tools/testing/selftests/vm mm: move slabinfo.c to tools/vm mm: move page-types.c from Documentation to tools/vm selftests/Makefile: make `run_tests' depend on `all' selftests: launch individual selftests from the main Makefile radix-tree: use iterators in find_get_pages* functions radix-tree: rewrite gang lookup using iterator radix-tree: introduce bit-optimized iterator fs/proc/namespaces.c: prevent crash when ns_entries[] is empty nbd: rename the nbd_device variable from lo to nbd pidns: add reboot_pid_ns() to handle the reboot syscall sysctl: use bitmap library functions ipmi: use locks on watchdog timeout set on reboot ipmi: simplify locking ipmi: fix message handling during panics ipmi: use a tasklet for handling received messages ipmi: increase KCS timeouts ipmi: decrease the IPMI message transaction time in interrupt mode ...
2012-03-28sysctl: use bitmap library functionsAkinobu Mita
Use bitmap_set() instead of using set_bit() for each bit. This conversion is valid because the bitmap is private in the function call and atomic bitops were unnecessary. This also includes minor change. - Use bitmap_copy() for shorter typing Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-03-28Merge tag 'split-asm_system_h-for-linus-20120328' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-asm_system Pull "Disintegrate and delete asm/system.h" from David Howells: "Here are a bunch of patches to disintegrate asm/system.h into a set of separate bits to relieve the problem of circular inclusion dependencies. I've built all the working defconfigs from all the arches that I can and made sure that they don't break. The reason for these patches is that I recently encountered a circular dependency problem that came about when I produced some patches to optimise get_order() by rewriting it to use ilog2(). This uses bitops - and on the SH arch asm/bitops.h drags in asm-generic/get_order.h by a circuituous route involving asm/system.h. The main difficulty seems to be asm/system.h. It holds a number of low level bits with no/few dependencies that are commonly used (eg. memory barriers) and a number of bits with more dependencies that aren't used in many places (eg. switch_to()). These patches break asm/system.h up into the following core pieces: (1) asm/barrier.h Move memory barriers here. This already done for MIPS and Alpha. (2) asm/switch_to.h Move switch_to() and related stuff here. (3) asm/exec.h Move arch_align_stack() here. Other process execution related bits could perhaps go here from asm/processor.h. (4) asm/cmpxchg.h Move xchg() and cmpxchg() here as they're full word atomic ops and frequently used by atomic_xchg() and atomic_cmpxchg(). (5) asm/bug.h Move die() and related bits. (6) asm/auxvec.h Move AT_VECTOR_SIZE_ARCH here. Other arch headers are created as needed on a per-arch basis." Fixed up some conflicts from other header file cleanups and moving code around that has happened in the meantime, so David's testing is somewhat weakened by that. We'll find out anything that got broken and fix it.. * tag 'split-asm_system_h-for-linus-20120328' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-asm_system: (38 commits) Delete all instances of asm/system.h Remove all #inclusions of asm/system.h Add #includes needed to permit the removal of asm/system.h Move all declarations of free_initmem() to linux/mm.h Disintegrate asm/system.h for OpenRISC Split arch_align_stack() out from asm-generic/system.h Split the switch_to() wrapper out of asm-generic/system.h Move the asm-generic/system.h xchg() implementation to asm-generic/cmpxchg.h Create asm-generic/barrier.h Make asm-generic/cmpxchg.h #include asm-generic/cmpxchg-local.h Disintegrate asm/system.h for Xtensa Disintegrate asm/system.h for Unicore32 [based on ver #3, changed by gxt] Disintegrate asm/system.h for Tile Disintegrate asm/system.h for Sparc Disintegrate asm/system.h for SH Disintegrate asm/system.h for Score Disintegrate asm/system.h for S390 Disintegrate asm/system.h for PowerPC Disintegrate asm/system.h for PA-RISC Disintegrate asm/system.h for MN10300 ...
2012-03-28Remove all #inclusions of asm/system.hDavid Howells
Remove all #inclusions of asm/system.h preparatory to splitting and killing it. Performed with the following command: perl -p -i -e 's!^#\s*include\s*<asm/system[.]h>.*\n!!' `grep -Irl '^#\s*include\s*<asm/system[.]h>' *` Signed-off-by: David Howells <dhowells@redhat.com>
2012-03-28Disintegrate asm/system.h for SparcDavid Howells
Disintegrate asm/system.h for Sparc. Signed-off-by: David Howells <dhowells@redhat.com> cc: sparclinux@vger.kernel.org
2012-03-23Merge git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/sysctlLinus Torvalds
Pull sysctl updates from Eric Biederman: - Rewrite of sysctl for speed and clarity. Insert/remove/Lookup in sysctl are all now O(NlogN) operations, and are no longer bottlenecks in the process of adding and removing network devices. sysctl is now focused on being a filesystem instead of system call and the code can all be found in fs/proc/proc_sysctl.c. Hopefully this means the code is now approachable. Much thanks is owed to Lucian Grinjincu for keeping at this until something was found that was usable. - The recent proc_sys_poll oops found by the fuzzer during hibernation is fixed. * git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/sysctl: (36 commits) sysctl: protect poll() in entries that may go away sysctl: Don't call sysctl_follow_link unless we are a link. sysctl: Comments to make the code clearer. sysctl: Correct error return from get_subdir sysctl: An easier to read version of find_subdir sysctl: fix memset parameters in setup_sysctl_set() sysctl: remove an unused variable sysctl: Add register_sysctl for normal sysctl users sysctl: Index sysctl directories with rbtrees. sysctl: Make the header lists per directory. sysctl: Move sysctl_check_dups into insert_header sysctl: Modify __register_sysctl_paths to take a set instead of a root and an nsproxy sysctl: Replace root_list with links between sysctl_table_sets. sysctl: Add sysctl_print_dir and use it in get_subdir sysctl: Stop requiring explicit management of sysctl directories sysctl: Add a root pointer to ctl_table_set sysctl: Rewrite proc_sys_readdir in terms of first_entry and next_entry sysctl: Rewrite proc_sys_lookup introducing find_entry and lookup_entry. sysctl: Normalize the root_table data structure. sysctl: Factor out insert_header and erase_header ...
2012-02-14security: trim security.hAl Viro
Trim security.h Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: James Morris <jmorris@namei.org>
2012-01-24sysctl: Move the implementation into fs/proc/proc_sysctl.cEric W. Biederman
Move the core sysctl code from kernel/sysctl.c and kernel/sysctl_check.c into fs/proc/proc_sysctl.c. Currently sysctl maintenance is hampered by the sysctl implementation being split across 3 files with artificial layering between them. Consolidate the entire sysctl implementation into 1 file so that it is easier to see what is going on and hopefully allowing for simpler maintenance. For functions that are now only used in fs/proc/proc_sysctl.c remove their declarations from sysctl.h and make them static in fs/proc/proc_sysctl.c Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2012-01-24sysctl: Register the base sysctl table like any other sysctl table.Eric W. Biederman
Simplify the code by treating the base sysctl table like any other sysctl table and register it with register_sysctl_table. To ensure this table is registered early enough to avoid problems call sysctl_init from proc_sys_init. Rename sysctl_net.c:sysctl_init() to net_sysctl_init() to avoid name conflicts now that kernel/sysctl.c:sysctl_init() is no longer static. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2012-01-24sysctl: Consolidate !CONFIG_SYSCTL handlingEric W. Biederman
- In sysctl.h move functions only available if CONFIG_SYSCL is defined inside of #ifdef CONFIG_SYSCTL - Move the stub function definitions for !CONFIG_SYSCTL into sysctl.h and make them static inlines. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2011-12-05x86: Panic on detection of stack overflowMitsuo Hayasaka
Currently, messages are just output on the detection of stack overflow, which is not sufficient for systems that need a high reliability. This is because in general the overflow may corrupt data, and the additional corruption may occur due to reading them unless systems stop. This patch adds the sysctl parameter kernel.panic_on_stackoverflow and causes a panic when detecting the overflows of kernel, IRQ and exception stacks except user stack according to the parameter. It is disabled by default. Signed-off-by: Mitsuo Hayasaka <mitsuo.hayasaka.hu@hitachi.com> Cc: yrl.pp-manager.tt@hitachi.com Cc: Randy Dunlap <rdunlap@xenotime.net> Cc: "H. Peter Anvin" <hpa@zytor.com> Link: http://lkml.kernel.org/r/20111129060836.11076.12323.stgit@ltc219.sdl.hitachi.co.jp Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-10-31Merge branch 'akpm' (Andrew's incoming)Linus Torvalds
Quoth Andrew: - Most of MM. Still waiting for the poweroc guys to get off their butts and review some threaded hugepages patches. - alpha - vfs bits - drivers/misc - a few core kerenl tweaks - printk() features - MAINTAINERS updates - backlight merge - leds merge - various lib/ updates - checkpatch updates * akpm: (127 commits) epoll: fix spurious lockdep warnings checkpatch: add a --strict check for utf-8 in commit logs kernel.h/checkpatch: mark strict_strto<foo> and simple_strto<foo> as obsolete llist-return-whether-list-is-empty-before-adding-in-llist_add-fix wireless: at76c50x: follow rename pack_hex_byte to hex_byte_pack fat: follow rename pack_hex_byte() to hex_byte_pack() security: follow rename pack_hex_byte() to hex_byte_pack() kgdb: follow rename pack_hex_byte() to hex_byte_pack() lib: rename pack_hex_byte() to hex_byte_pack() lib/string.c: fix strim() semantics for strings that have only blanks lib/idr.c: fix comment for ida_get_new_above() lib/percpu_counter.c: enclose hotplug only variables in hotplug ifdef lib/bitmap.c: quiet sparse noise about address space lib/spinlock_debug.c: print owner on spinlock lockup lib/kstrtox: common code between kstrto*() and simple_strto*() functions drivers/leds/leds-lp5521.c: check if reset is successful leds: turn the blink_timer off before starting to blink leds: save the delay values after a successful call to blink_set() drivers/leds/leds-gpio.c: use gpio_get_value_cansleep() when initializing drivers/leds/leds-lm3530.c: add __devexit_p where needed ...
2011-10-31kernel/sysctl.c: add cap_last_cap to /proc/sys/kernelDan Ballard
Userspace needs to know the highest valid capability of the running kernel, which right now cannot reliably be retrieved from the header files only. The fact that this value cannot be determined properly right now creates various problems for libraries compiled on newer header files which are run on older kernels. They assume capabilities are available which actually aren't. libcap-ng is one example. And we ran into the same problem with systemd too. Now the capability is exported in /proc/sys/kernel/cap_last_cap. [akpm@linux-foundation.org: make cap_last_cap const, per Ulrich] Signed-off-by: Dan Ballard <dan@mindstab.net> Cc: Randy Dunlap <rdunlap@xenotime.net> Cc: Ingo Molnar <mingo@elte.hu> Cc: Lennart Poettering <lennart@poettering.net> Cc: Kay Sievers <kay.sievers@vrfy.org> Cc: Ulrich Drepper <drepper@akkadia.org> Cc: James Morris <jmorris@namei.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-10-30[S390] sparse: fix sparse warnings about missing prototypesMartin Schwidefsky
Add prototypes and includes for functions used in different modules. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2011-08-14sched: Accumulate per-cfs_rq cpu usage and charge against bandwidthPaul Turner
Account bandwidth usage on the cfs_rq level versus the task_groups to which they belong. Whether we are tracking bandwidth on a given cfs_rq is maintained under cfs_rq->runtime_enabled. cfs_rq's which belong to a bandwidth constrained task_group have their runtime accounted via the update_curr() path, which withdraws bandwidth from the global pool as desired. Updates involving the global pool are currently protected under cfs_bandwidth->lock, local runtime is protected by rq->lock. This patch only assigns and tracks quota, no action is taken in the case that cfs_rq->runtime_used exceeds cfs_rq->runtime_assigned. Signed-off-by: Paul Turner <pjt@google.com> Signed-off-by: Nikhil Rao <ncrao@google.com> Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com> Reviewed-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110721184757.179386821@google.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-20sysctl,rcu: Convert call_rcu(free_head) to kfreePaul E. McKenney
The RCU callback free_head just calls kfree(), so we can use kfree_rcu() instead of call_rcu(). Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
2011-06-04perf: Comment /proc/sys/kernel/perf_event_paranoid to be part of user ABIVince Weaver
Turns out that distro packages use this file as an indicator of the perf event subsystem - this is easier to check for from scripts than the existence of the system call. This is easy enough to keep around for the kernel, so add a comment to make sure it stays so. Signed-off-by: Vince Weaver <vweaver1@eecs.utk.edu> Cc: David Ahern <dsahern@gmail.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: paulus@samba.org Cc: acme@redhat.com Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/alpine.DEB.2.00.1106031751170.29381@cl320.eecs.utk.edu Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-05-25Merge git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tileLinus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile: (26 commits) arch/tile: prefer "tilepro" as the name of the 32-bit architecture compat: include aio_abi.h for aio_context_t arch/tile: cleanups for tilegx compat mode arch/tile: allocate PCI IRQs later in boot arch/tile: support signal "exception-trace" hook arch/tile: use better definitions of xchg() and cmpxchg() include/linux/compat.h: coding-style fixes tile: add an RTC driver for the Tilera hypervisor arch/tile: finish enabling support for TILE-Gx 64-bit chip compat: fixes to allow working with tile arch arch/tile: update defconfig file to something more useful tile: do_hardwall_trap: do not play with task->sighand tile: replace mm->cpu_vm_mask with mm_cpumask() tile,mn10300: add device parameter to dma_cache_sync() audit: support the "standard" <asm-generic/unistd.h> arch/tile: clarify flush_buffer()/finv_buffer() function names arch/tile: kernel-related cleanups from removing static page size arch/tile: various header improvements for building drivers arch/tile: disable GX prefetcher during cache flush arch/tile: tolerate disabling CONFIG_BLK_DEV_INITRD ...
2011-05-24Merge branch 'next' into for-linusJames Morris
2011-05-23watchdog: Disable watchdog when thresh is zeroMandeep Singh Baines
This restores the previous behavior of softlock_thresh. Currently, setting watchdog_thresh to zero causes the watchdog kthreads to consume a lot of CPU. In addition, the logic of proc_dowatchdog_thresh and proc_dowatchdog_enabled has been factored into proc_dowatchdog. Signed-off-by: Mandeep Singh Baines <msb@chromium.org> Cc: Marcin Slusarz <marcin.slusarz@gmail.com> Cc: Don Zickus <dzickus@redhat.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Frederic Weisbecker <fweisbec@gmail.com> Link: http://lkml.kernel.org/r/1306127423-3347-3-git-send-email-msb@chromium.org Signed-off-by: Ingo Molnar <mingo@elte.hu> LKML-Reference: <20110517071018.GE22305@elte.hu>
2011-05-19arch/tile: support signal "exception-trace" hookChris Metcalf
This change adds support for /proc/sys/debug/exception-trace to tile. Like x86 and sparc, by default it is set to "1", generating a one-line printk whenever a user process crashes. By setting it to "2", we get a much more complete userspace diagnostic at crash time, including a user-space backtrace, register dump, and memory dump around the address of the crash. Some vestiges of the Tilera-internal version of this support are removed with this patch (the show_crashinfo variable and the arch_coredump_signal function). We retain a "crashinfo" boot parameter which allows you to set the boot-time value of exception-trace. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2011-04-04capabilites: allow the application of capability limits to usermode helpersEric Paris
There is no way to limit the capabilities of usermodehelpers. This problem reared its head recently when someone complained that any user with cap_net_admin was able to load arbitrary kernel modules, even though the user didn't have cap_sys_module. The reason is because the actual load is done by a usermode helper and those always have the full cap set. This patch addes new sysctls which allow us to bound the permissions of usermode helpers. /proc/sys/kernel/usermodehelper/bset /proc/sys/kernel/usermodehelper/inheritable You must have CAP_SYS_MODULE and CAP_SETPCAP to change these (changes are &= ONLY). When the kernel launches a usermodehelper it will do so with these as the bset and pI. -v2: make globals static create spinlock to protect globals -v3: require both CAP_SETPCAP and CAP_SYS_MODULE -v4: fix the typo s/CAP_SET_PCAP/CAP_SETPCAP/ because I didn't commit Signed-off-by: Eric Paris <eparis@redhat.com> No-objection-from: Serge E. Hallyn <serge.hallyn@canonical.com> Acked-by: David Howells <dhowells@redhat.com> Acked-by: Serge E. Hallyn <serge.hallyn@canonical.com> Acked-by: Andrew G. Morgan <morgan@kernel.org> Signed-off-by: James Morris <jmorris@namei.org>
2011-03-23sysctl: restrict write access to dmesg_restrictRichard Weinberger
When dmesg_restrict is set to 1 CAP_SYS_ADMIN is needed to read the kernel ring buffer. But a root user without CAP_SYS_ADMIN is able to reset dmesg_restrict to 0. This is an issue when e.g. LXC (Linux Containers) are used and complete user space is running without CAP_SYS_ADMIN. A unprivileged and jailed root user can bypass the dmesg_restrict protection. With this patch writing to dmesg_restrict is only allowed when root has CAP_SYS_ADMIN. Signed-off-by: Richard Weinberger <richard@nod.at> Acked-by: Dan Rosenberg <drosenberg@vsecurity.com> Acked-by: Serge E. Hallyn <serge@hallyn.com> Cc: Eric Paris <eparis@redhat.com> Cc: Kees Cook <kees.cook@canonical.com> Cc: James Morris <jmorris@namei.org> Cc: Eugene Teo <eugeneteo@kernel.org> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-23sysctl: add some missing input constraint checksPetr Holasek
Add boundaries of allowed input ranges for: dirty_expire_centisecs, drop_caches, overcommit_memory, page-cluster and panic_on_oom. Signed-off-by: Petr Holasek <pholasek@redhat.com> Acked-by: Dave Young <hidave.darkstar@gmail.com> Cc: David Rientjes <rientjes@google.com> Cc: Wu Fengguang <fengguang.wu@intel.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-16Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6 * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6: (33 commits) AppArmor: kill unused macros in lsm.c AppArmor: cleanup generated files correctly KEYS: Add an iovec version of KEYCTL_INSTANTIATE KEYS: Add a new keyctl op to reject a key with a specified error code KEYS: Add a key type op to permit the key description to be vetted KEYS: Add an RCU payload dereference macro AppArmor: Cleanup make file to remove cruft and make it easier to read SELinux: implement the new sb_remount LSM hook LSM: Pass -o remount options to the LSM SELinux: Compute SID for the newly created socket SELinux: Socket retains creator role and MLS attribute SELinux: Auto-generate security_is_socket_class TOMOYO: Fix memory leak upon file open. Revert "selinux: simplify ioctl checking" selinux: drop unused packet flow permissions selinux: Fix packet forwarding checks on postrouting selinux: Fix wrong checks for selinux_policycap_netpeer selinux: Fix check for xfrm selinux context algorithm ima: remove unnecessary call to ima_must_measure IMA: remove IMA imbalance checking ...
2011-03-15Merge branch 'sched-core-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (26 commits) sched: Resched proper CPU on yield_to() sched: Allow users with sufficient RLIMIT_NICE to change from SCHED_IDLE policy sched: Allow SCHED_BATCH to preempt SCHED_IDLE tasks sched: Clean up the IRQ_TIME_ACCOUNTING code sched: Add #ifdef around irq time accounting functions sched, autogroup: Stop claiming ownership of the root task group sched, autogroup: Stop going ahead if autogroup is disabled sched, autogroup, sysctl: Use proc_dointvec_minmax() instead sched: Fix the group_imb logic sched: Clean up some f_b_g() comments sched: Clean up remnants of sd_idle sched: Wholesale removal of sd_idle logic sched: Add yield_to(task, preempt) functionality sched: Use a buddy to implement yield_task_fair() sched: Limit the scope of clear_buddies sched: Check the right ->nr_running in yield_task_fair() sched: Avoid expensive initial update_cfs_load(), on UP too sched: Fix switch_from_fair() sched: Simplify the idle scheduling class softirqs: Account ksoftirqd time as cpustat softirq ...
2011-03-15Merge branch 'perf-core-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (184 commits) perf probe: Clean up probe_point_lazy_walker() return value tracing: Fix irqoff selftest expanding max buffer tracing: Align 4 byte ints together in struct tracer tracing: Export trace_set_clr_event() tracing: Explain about unstable clock on resume with ring buffer warning ftrace/graph: Trace function entry before updating index ftrace: Add .ref.text as one of the safe areas to trace tracing: Adjust conditional expression latency formatting. tracing: Fix event alignment: skb:kfree_skb tracing: Fix event alignment: mce:mce_record tracing: Fix event alignment: kvm:kvm_hv_hypercall tracing: Fix event alignment: module:module_request tracing: Fix event alignment: ftrace:context_switch and ftrace:wakeup tracing: Remove lock_depth from event entry perf header: Stop using 'self' perf session: Use evlist/evsel for managing perf.data attributes perf top: Don't let events to eat up whole header line perf top: Fix events overflow in top command ring-buffer: Remove unused #include <linux/trace_irq.h> tracing: Add an 'overwrite' trace_option. ...
2011-03-16Merge branch 'next' into for-linusJames Morris
2011-03-08unfuck proc_sysctl ->d_compare()Al Viro
a) struct inode is not going to be freed under ->d_compare(); however, the thing PROC_I(inode)->sysctl points to just might. Fortunately, it's enough to make freeing that sucker delayed, provided that we don't step on its ->unregistering, clear the pointer to it in PROC_I(inode) before dropping the reference and check if it's NULL in ->d_compare(). b) I'm not sure that we *can* walk into NULL inode here (we recheck dentry->seq between verifying that it's still hashed / fetching dentry->d_inode and passing it to ->d_compare() and there's no negative hashed dentries in /proc/sys/*), but if we can walk into that, we really should not have ->d_compare() return 0 on it! Said that, I really suspect that this check can be simply killed. Nick? Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-03-08Merge branch 'master' of git://git.infradead.org/users/eparis/selinux into nextJames Morris
2011-02-23sched, autogroup, sysctl: Use proc_dointvec_minmax() insteadYong Zhang
sched_autogroup_enabled has min/max value, proc_dointvec_minmax() is be used for this case. Signed-off-by: Yong Zhang <yong.zhang0@gmail.com> Cc: Mike Galbraith <efault@gmx.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1298185696-4403-2-git-send-email-yong.zhang0@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-02-16Merge commit 'v2.6.38-rc5' into sched/coreIngo Molnar
Merge reason: Pick up upstream fixes. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-02-16perf: Optimize throttling codePeter Zijlstra
By pre-computing the maximum number of samples per tick we can avoid a multiplication and a conditional since MAX_INTERRUPTS > max_samples_per_tick. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-02-03sched: Use a buddy to implement yield_task_fair()Rik van Riel
Use the buddy mechanism to implement yield_task_fair. This allows us to skip onto the next highest priority se at every level in the CFS tree, unless doing so would introduce gross unfairness in CPU time distribution. We order the buddy selection in pick_next_entity to check yield first, then last, then next. We need next to be able to override yield, because it is possible for the "next" and "yield" task to be different processen in the same sub-tree of the CFS tree. When they are, we need to go into that sub-tree regardless of the "yield" hint, and pick the correct entity once we get to the right level. Signed-off-by: Rik van Riel <riel@redhat.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20110201095103.3a79e92a@annuminas.surriel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-02-01security: remove unused security_sysctl hookLucian Adrian Grijincu
The only user for this hook was selinux. sysctl routes every call through /proc/sys/. Selinux and other security modules use the file system checks for sysctl too, so no need for this hook any more. Signed-off-by: Lucian Adrian Grijincu <lucian.grijincu@gmail.com> Signed-off-by: Eric Paris <eparis@redhat.com>
2011-01-26Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input: Input: wacom - pass touch resolution to clients through input_absinfo Input: wacom - add 2 Bamboo Pen and touch models Input: sysrq - ensure sysrq_enabled and __sysrq_enabled are consistent Input: sparse-keymap - fix KEY_VSW handling in sparse_keymap_setup Input: tegra-kbc - add tegra keyboard driver Input: gpio_keys - switch to using request_any_context_irq Input: serio - allow registered drivers to get status flag Input: ct82710c - return proper error code for ct82c710_open Input: bu21013_ts - added regulator support Input: bu21013_ts - remove duplicate resolution parameters Input: tnetv107x-ts - don't treat NULL clk as an error Input: tnetv107x-keypad - don't treat NULL clk as an error Fix up trivial conflicts in drivers/input/keyboard/Makefile due to additions of tc3589x/Tegra drivers
2011-01-24Input: sysrq - ensure sysrq_enabled and __sysrq_enabled are consistentAndy Whitcroft
Currently sysrq_enabled and __sysrq_enabled are initialised separately and inconsistently, leading to sysrq being actually enabled by reported as not enabled in sysfs. The first change to the sysfs configurable synchronises these two: static int __read_mostly sysrq_enabled = 1; static int __sysrq_enabled; Add a common define to carry the default for these preventing them becoming out of sync again. Default this to 1 to mirror previous behaviour. Signed-off-by: Andy Whitcroft <apw@canonical.com> Cc: stable@kernel.org Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
2011-01-13sysctl: remove obsolete commentsJovi Zhang
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 <bookjovi@gmail.com> Cc: Dave Young <hidave.darkstar@gmail.com> Acked-by: WANG Cong <xiyou.wangcong@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-13sysctl: fix #ifdef guard commentJovi Zhang
Signed-off-by: Jovi Zhang <bookjovi@gmail.com> Acked-by: WANG Cong <xiyou.wangcong@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-13kptr_restrict for hiding kernel pointers from unprivileged usersDan Rosenberg
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 <drosenberg@vsecurity.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Cc: James Morris <jmorris@namei.org> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: Thomas Graf <tgraf@infradead.org> Cc: Eugene Teo <eugeneteo@kernel.org> Cc: Kees Cook <kees.cook@canonical.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: David S. Miller <davem@davemloft.net> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Eric Paris <eparis@parisplace.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-06Merge branch 'sched-core-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (30 commits) sched: Change wait_for_completion_*_timeout() to return a signed long sched, autogroup: Fix reference leak sched, autogroup: Fix potential access to freed memory sched: Remove redundant CONFIG_CGROUP_SCHED ifdef sched: Fix interactivity bug by charging unaccounted run-time on entity re-weight sched: Move periodic share updates to entity_tick() printk: Use this_cpu_{read|write} api on printk_pending sched: Make pushable_tasks CONFIG_SMP dependant sched: Add 'autogroup' scheduling feature: automated per session task groups sched: Fix unregister_fair_sched_group() sched: Remove unused argument dest_cpu to migrate_task() mutexes, sched: Introduce arch_mutex_cpu_relax() sched: Add some clock info to sched_debug cpu: Remove incorrect BUG_ON cpu: Remove unused variable sched: Fix UP build breakage sched: Make task dump print all 15 chars of proc comm sched: Update tg->shares after cpu.shares write sched: Allow update_cfs_load() to update global load sched: Implement demand based update_cfs_load() ...
2010-12-10x86, NMI: Add back unknown_nmi_panic and nmi_watchdog sysctlsDon Zickus
Originally adapted from Huang Ying's patch which moved the unknown_nmi_panic to the traps.c file. Because the old nmi watchdog was deleted before this change happened, the unknown_nmi_panic sysctl was lost. This re-adds it. Also, the nmi_watchdog sysctl was re-implemented and its documentation updated accordingly. Patch-inspired-by: Huang Ying <ying.huang@intel.com> Signed-off-by: Don Zickus <dzickus@redhat.com> Reviewed-by: Cyrill Gorcunov <gorcunov@gmail.com> Acked-by: Yinghai Lu <yinghai@kernel.org> Cc: fweisbec@gmail.com LKML-Reference: <1291068437-5331-3-git-send-email-dzickus@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-30sched: Add 'autogroup' scheduling feature: automated per session task groupsMike Galbraith
A recurring complaint from CFS users is that parallel kbuild has a negative impact on desktop interactivity. This patch implements an idea from Linus, to automatically create task groups. Currently, only per session autogroups are implemented, but the patch leaves the way open for enhancement. Implementation: each task's signal struct contains an inherited pointer to a refcounted autogroup struct containing a task group pointer, the default for all tasks pointing to the init_task_group. When a task calls setsid(), a new task group is created, the process is moved into the new task group, and a reference to the preveious task group is dropped. Child processes inherit this task group thereafter, and increase it's refcount. When the last thread of a process exits, the process's reference is dropped, such that when the last process referencing an autogroup exits, the autogroup is destroyed. At runqueue selection time, IFF a task has no cgroup assignment, its current autogroup is used. Autogroup bandwidth is controllable via setting it's nice level through the proc filesystem: cat /proc/<pid>/autogroup Displays the task's group and the group's nice level. echo <nice level> > /proc/<pid>/autogroup Sets the task group's shares to the weight of nice <level> task. Setting nice level is rate limited for !admin users due to the abuse risk of task group locking. The feature is enabled from boot by default if CONFIG_SCHED_AUTOGROUP=y is selected, but can be disabled via the boot option noautogroup, and can also be turned on/off on the fly via: echo [01] > /proc/sys/kernel/sched_autogroup_enabled ... which will automatically move tasks to/from the root task group. Signed-off-by: Mike Galbraith <efault@gmx.de> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Markus Trippelsdorf <markus@trippelsdorf.de> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Paul Turner <pjt@google.com> Cc: Oleg Nesterov <oleg@redhat.com> [ Removed the task_group_path() debug code, and fixed !EVENTFD build failure. ] Signed-off-by: Ingo Molnar <mingo@elte.hu> LKML-Reference: <1290281700.28711.9.camel@maggy.simson.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-26Merge commit 'v2.6.37-rc3' into sched/coreIngo Molnar
Merge reason: Pick up latest fixes. Signed-off-by: Ingo Molnar <mingo@elte.hu>