summaryrefslogtreecommitdiffstats
path: root/kernel/sysctl.c (follow)
Commit message (Collapse)AuthorAgeFilesLines
* V3 file capabilities: alter behavior of cap_setpcapAndrew Morgan2007-10-181-2/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The non-filesystem capability meaning of CAP_SETPCAP is that a process, p1, can change the capabilities of another process, p2. This is not the meaning that was intended for this capability at all, and this implementation came about purely because, without filesystem capabilities, there was no way to use capabilities without one process bestowing them on another. Since we now have a filesystem support for capabilities we can fix the implementation of CAP_SETPCAP. The most significant thing about this change is that, with it in effect, no process can set the capabilities of another process. The capabilities of a program are set via the capability convolution rules: pI(post-exec) = pI(pre-exec) pP(post-exec) = (X(aka cap_bset) & fP) | (pI(post-exec) & fI) pE(post-exec) = fE ? pP(post-exec) : 0 at exec() time. As such, the only influence the pre-exec() program can have on the post-exec() program's capabilities are through the pI capability set. The correct implementation for CAP_SETPCAP (and that enabled by this patch) is that it can be used to add extra pI capabilities to the current process - to be picked up by subsequent exec()s when the above convolution rules are applied. Here is how it works: Let's say we have a process, p. It has capability sets, pE, pP and pI. Generally, p, can change the value of its own pI to pI' where (pI' & ~pI) & ~pP = 0. That is, the only new things in pI' that were not present in pI need to be present in pP. The role of CAP_SETPCAP is basically to permit changes to pI beyond the above: if (pE & CAP_SETPCAP) { pI' = anything; /* ie., even (pI' & ~pI) & ~pP != 0 */ } This capability is useful for things like login, which (say, via pam_cap) might want to raise certain inheritable capabilities for use by the children of the logged-in user's shell, but those capabilities are not useful to or needed by the login program itself. One such use might be to limit who can run ping. You set the capabilities of the 'ping' program to be "= cap_net_raw+i", and then only shells that have (pI & CAP_NET_RAW) will be able to run it. Without CAP_SETPCAP implemented as described above, login(pam_cap) would have to also have (pP & CAP_NET_RAW) in order to raise this capability and pass it on through the inheritable set. Signed-off-by: Andrew Morgan <morgan@kernel.org> Signed-off-by: Serge E. Hallyn <serue@us.ibm.com> Cc: Stephen Smalley <sds@tycho.nsa.gov> Cc: James Morris <jmorris@namei.org> Cc: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* sysctl: deprecate sys_sysctl in a user space visible fashion.Eric W. Biederman2007-10-181-23/+41
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | After adding checking to register_sysctl_table and finding a whole new set of bugs. Missed by countless code reviews and testers I have finally lost patience with the binary sysctl interface. The binary sysctl interface has been sort of deprecated for years and finding a user space program that uses the syscall is more difficult then finding a needle in a haystack. Problems continue to crop up, with the in kernel implementation. So since supporting something that no one uses is silly, deprecate sys_sysctl with a sufficient grace period and notice that the handful of user space applications that care can be fixed or replaced. The /proc/sys sysctl interface that people use will continue to be supported indefinitely. This patch moves the tested warning about sysctls from the path where sys_sysctl to a separate path called from both implementations of sys_sysctl, and it adds a proper entry into Documentation/feature-removal-schedule. Allowing us to revisit this in a couple years time and actually kill sys_sysctl. [lethal@linux-sh.org: sysctl: Fix syscall disabled build] Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Paul Mundt <lethal@linux-sh.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* sysctl: Error on bad sysctl tablesEric W. Biederman2007-10-181-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | After going through the kernels sysctl tables several times it has become clear that code review and testing is just not effective in prevent problematic sysctl tables from being used in the stable kernel. I certainly can't seem to fix the problems as fast as they are introduced. Therefore this patch adds sysctl_check_table which is called when a sysctl table is registered and checks to see if we have a problematic sysctl table. The biggest part of the code is the table of valid binary sysctl entries, but since we have frozen our set of binary sysctls this table should not need to change, and it makes it much easier to detect when someone unintentionally adds a new binary sysctl value. As best as I can determine all of the several hundred errors spewed on boot up now are legitimate. [bunk@kernel.org: kernel/sysctl_check.c must #include <linux/string.h>] Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Cc: Alexey Dobriyan <adobriyan@sw.ru> Signed-off-by: Adrian Bunk <bunk@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* sysctl: remove the cad_pid binary sysctl pathEric W. Biederman2007-10-181-1/+0
| | | | | | | | | | It looks like we inadvertently killed the cad_pid binary sysctl support when cap_pid was changed to be a struct pid. Since no one has complained just remove the binary path. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* sysctl: simplify the pty sysctl logicEric W. Biederman2007-10-181-11/+0
| | | | | | | | | | | | | Instead of having a bunch of ifdefs in sysctl.c move all of the pty sysctl logic into drivers/char/pty.c As well as cleaning up the logic this prevents sysctl_check_table from complaining that the root table has a NULL data pointer on something with generic methods. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* sysctl: remove the binary interface for aio-nr, aio-max-nr, acpi_video_flagsEric W. Biederman2007-10-181-3/+0
| | | | | | | | | | | | | | | | | | aio-nr, aio-max-nr, acpi_video_flags are unsigned long values which sysctl does not handle properly with a 64bit kernel and a 32bit user space. Since no one is likely to be using the binary sysctl values and the ascii interface still works, this patch just removes support for the binary sysctl interface from the kernel. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Cc: Alexey Dobriyan <adobriyan@sw.ru> Cc: Benjamin LaHaise <bcrl@kvack.org> Cc: Zach Brown <zach.brown@oracle.com> Cc: Badari Pulavarty <pbadari@us.ibm.com> Cc: Len Brown <lenb@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* sysctl: remove binary sysctl support where it clearly doesn't workEric W. Biederman2007-10-181-7/+0
| | | | | | | | | | | These functions are all wrapper functions for the proc interface that are needed for them to work correctly. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Cc: Alexey Dobriyan <adobriyan@sw.ru> Acked-by: Andrew Morgan <morgan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* sysctl: Factor out sysctl_data.Eric W. Biederman2007-10-181-20/+46
| | | | | | | | | | | | | | | | | | | | There as been no easy way to wrap the default sysctl strategy routine except for returning 0. Which is not always what we want. The few instances I have seen that want different behaviour have written their own version of sysctl_data. While not too hard it is unnecessary code and has the potential for extra bugs. So to make these situations easier and make that part of sysctl more symetric I have factord sysctl_data out of do_sysctl_strategy and exported as a function everyone can use. Further having sysctl_data be an explicit function makes checking for badly formed sysctl tables much easier. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Cc: Alexey Dobriyan <adobriyan@sw.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* sysctl core: Stop using the unnecessary ctl_table typedefEric W. Biederman2007-10-181-57/+57
| | | | | | | | | | | | | | | In sysctl.h the typedef struct ctl_table ctl_table violates coding style isn't needed and is a bit of a nuisance because it makes it harder to recognize ctl_table is a type name. So this patch removes it from the generic sysctl code. Hopefully I will have enough energy to send the rest of my patches will follow and to remove it from the rest of the kernel. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Cc: Alexey Dobriyan <adobriyan@sw.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* softlockup: add a /proc tuning parameterRavikiran G Thirumalai2007-10-171-7/+26
| | | | | | | | | | | | | | | | | | Control the trigger limit for softlockup warnings. This is useful for debugging softlockups, by lowering the softlockup_thresh to identify possible softlockups earlier. This patch: 1. Adds a sysctl softlockup_thresh with valid values of 1-60s (Higher value to disable false positives) 2. Changes the softlockup printk to print the cpu softlockup time [akpm@linux-foundation.org: Fix various warnings and add definition of "two"] Signed-off-by: Ravikiran Thirumalai <kiran@scalex86.org> Signed-off-by: Shai Fultheim <shai@scalex86.org> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* oom: add oom_kill_allocating_task sysctlDavid Rientjes2007-10-171-0/+9
| | | | | | | | | | | | | | Adds a new sysctl, 'oom_kill_allocating_task', which will automatically kill the OOM-triggering task instead of scanning through the tasklist to find a memory-hogging target. This is helpful for systems with an insanely large number of tasks where scanning the tasklist significantly degrades performance. Cc: Andrea Arcangeli <andrea@suse.de> Acked-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: per device dirty thresholdPeter Zijlstra2007-10-171-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Scale writeback cache per backing device, proportional to its writeout speed. By decoupling the BDI dirty thresholds a number of problems we currently have will go away, namely: - mutual interference starvation (for any number of BDIs); - deadlocks with stacked BDIs (loop, FUSE and local NFS mounts). It might be that all dirty pages are for a single BDI while other BDIs are idling. By giving each BDI a 'fair' share of the dirty limit, each one can have dirty pages outstanding and make progress. A global threshold also creates a deadlock for stacked BDIs; when A writes to B, and A generates enough dirty pages to get throttled, B will never start writeback until the dirty pages go away. Again, by giving each BDI its own 'independent' dirty limit, this problem is avoided. So the problem is to determine how to distribute the total dirty limit across the BDIs fairly and efficiently. A DBI that has a large dirty limit but does not have any dirty pages outstanding is a waste. What is done is to keep a floating proportion between the DBIs based on writeback completions. This way faster/more active devices get a larger share than slower/idle devices. [akpm@linux-foundation.org: fix warnings] [hugh@veritas.com: Fix occasional hang when a task couldn't get out of balance_dirty_pages] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* hugetlb: Add hugetlb_dynamic_pool sysctlAdam Litke2007-10-161-0/+8
| | | | | | | | | | | | | | | | | | | | | | The maximum size of the huge page pool can be controlled using the overall size of the hugetlb filesystem (via its 'size' mount option). However in the common case the this will not be set as the pool is traditionally fixed in size at boot time. In order to maintain the expected semantics, we need to prevent the pool expanding by default. This patch introduces a new sysctl controlling dynamic pool resizing. When this is enabled the pool will expand beyond its base size up to the size of the hugetlb filesystem. It is disabled by default. Signed-off-by: Adam Litke <agl@us.ibm.com> Acked-by: Andy Whitcroft <apw@shadowen.org> Acked-by: Dave McCracken <dave.mccracken@oracle.com> Cc: William Irwin <bill.irwin@oracle.com> Cc: David Gibson <david@gibson.dropbear.id.au> Cc: Ken Chen <kenchen@google.com> Cc: Badari Pulavarty <pbadari@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* sched: reintroduce cache-hot affinityIngo Molnar2007-10-151-0/+8
| | | | | | | | reintroduce a simplified version of cache-hot/cold scheduling affinity. This improves performance with certain SMP workloads, such as sysbench. Signed-off-by: Ingo Molnar <mingo@elte.hu>
* sched: speed up and simplify vslice calculationsPeter Zijlstra2007-10-151-6/+3
| | | | | | | | | speed up and simplify vslice calculations. [ From: Mike Galbraith <efault@gmx.de>: build fix ] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* sched: remove wait_runtime limitIngo Molnar2007-10-151-11/+0
| | | | | | | | | | remove the wait_runtime-limit fields and the code depending on it, now that the math has been changed over to rely on the vruntime metric. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Mike Galbraith <efault@gmx.de> Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
* sched: remove stat_granIngo Molnar2007-10-151-11/+0
| | | | | | | | | | remove the stat_gran code - it was disabled by default and it causes unnecessary overhead. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Mike Galbraith <efault@gmx.de> Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
* minimal build fixes for uml (fallout from x86 merge)Al Viro2007-10-131-1/+1
| | | | | | | | | | | | | | | | | | | a) include/asm-um/arch can't just point to include/asm-$(SUBARCH) now b) arch/{i386,x86_64}/crypto are merged now c) subarch-obj needed changes d) cpufeature_64.h should pull "cpufeature_32.h", not <asm/cpufeature_32.h> since it can be included from asm-um/cpufeature.h e) in case of uml-i386 we need CONFIG_X86_32 for make and gcc, but not for Kconfig f) sysctl.c shouldn't do vdso_enabled for uml-i386 (actually, that one should be registered from corresponding arch/*/kernel/*, with ifdef going away; that's a separate patch, though). With that and with Stephen's patch ("[PATCH net-2.6] uml: hard_header fix") we have uml allmodconfig building both on i386 and amd64. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [POWERPC] Implement logging of unhandled signalsOlof Johansson2007-10-121-1/+1
| | | | | | | | | | Implement show_unhandled_signals sysctl + support to print when a process is killed due to unhandled signals just as i386 and x86_64 does. Default to having it off, unlike x86 that defaults on. Signed-off-by: Olof Johansson <olof@lixom.net> Signed-off-by: Paul Mackerras <paulus@samba.org>
* sched: add /proc/sys/kernel/sched_compat_yieldIngo Molnar2007-09-191-0/+8
| | | | | | | | | | | | | | | | | | | | | add /proc/sys/kernel/sched_compat_yield to make sys_sched_yield() more agressive, by moving the yielding task to the last position in the rbtree. with sched_compat_yield=0: PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 2539 mingo 20 0 1576 252 204 R 50 0.0 0:02.03 loop_yield 2541 mingo 20 0 1576 244 196 R 50 0.0 0:02.05 loop with sched_compat_yield=1: PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 2584 mingo 20 0 1576 248 196 R 99 0.0 0:52.45 loop 2582 mingo 20 0 1576 256 204 R 0 0.0 0:00.00 loop_yield Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
* sched: cleanup, sched_granularity -> sched_min_granularityIngo Molnar2007-08-251-2/+2
| | | | | | | | | due to adaptive granularity scheduling the role of sched_granularity has changed to "minimum granularity", so rename the variable (and the tunable) accordingly. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
* sched: adaptive scheduler granularityPeter Zijlstra2007-08-251-0/+11
| | | | | | | | | | | | | | | | | | Instead of specifying the preemption granularity, specify the wanted latency. By fixing the granlarity to a constany the wakeup latency it a function of the number of running tasks on the rq. Invert this relation. sysctl_sched_granularity becomes a minimum for the dynamic granularity computed from the new sysctl_sched_latency. Then use this latency to do more intelligent granularity decisions: if there are fewer tasks running then we can schedule coarser. This helps performance while still always keeping the latency target. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* sched: fix CONFIG_SCHED_DEBUG dependency of lockdep sysctlsPeter Zijlstra2007-08-251-9/+9
| | | | | | | Make the lockdep sysctls not depend on CONFIG_SCHED_DEBUG. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* Remove double inclusion of linux/capability.hChristian Heim2007-08-191-1/+0
| | | | | | | | | Remove the second inclusion of linux/capability.h, which has been introduced with "[PATCH] move capable() to capability.h" (commit c59ede7b78db329949d9cdcd7064e22d357560ef) Signed-off-by: Christian Heim <phreak@gentoo.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Fix missing numa_zonelist_order sysctlLee Schermerhorn2007-08-121-1/+1
| | | | | | | | | Misplaced #endif is hiding the numa_zonelist_order sysctl when !SECURITY. Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Mel Gorman <mel@csn.ul.ie> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* ACPI: restore CONFIG_ACPI_SLEEPLen Brown2007-07-301-1/+1
| | | | | | | | | Restore the 2.6.22 CONFIG_ACPI_SLEEP build option, but now shadowing the new CONFIG_PM_SLEEP option. Signed-off-by: Len Brown <len.brown@intel.com> [ Modified to work with the PM config setup changes. ] Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* ACPI: Kconfig: remove CONFIG_ACPI_SLEEP from sourceLen Brown2007-07-251-1/+1
| | | | | | | | | | As it was a synonym for (CONFIG_ACPI && CONFIG_X86), the ifdefs for it were more clutter than they were worth. For ia64, just add a few stubs in anticipation of future S3 or S4 support. Signed-off-by: Len Brown <len.brown@intel.com>
* x86: i386-show-unhandled-signals-v3Masoud Asgharifard Sharbiani2007-07-221-0/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch makes the i386 behave the same way that x86_64 does when a segfault happens. A line gets printed to the kernel log so that tools that need to check for failures can behave more uniformly between debug.show_unhandled_signals sysctl variable to 0 (or by doing echo 0 > /proc/sys/debug/exception-trace) Also, all of the lines being printed are now using printk_ratelimit() to deny the ability of DoS from a local user with a program like the following: main() { while (1) if (!fork()) *(int *)0 = 0; } This new revision also includes the fix that Andrew did which got rid of new sysctl that was added to the system in earlier versions of this. Also, 'show-unhandled-signals' sysctl has been renamed back to the old 'exception-trace' to avoid breakage of people's scripts. AK: Enabling by default for i386 will be likely controversal, but let's see what happens AK: Really folks, before complaining just fix your segfaults AK: I bet this will find a lot of silent issues Signed-off-by: Masoud Sharbiani <masouds@google.com> Signed-off-by: Andi Kleen <ak@suse.de> [ Personally, I've found the complaints useful on x86-64, so I'm all for this. That said, I wonder if we could do it more prettily.. -Linus ] Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* kernel/sysctl.c: finish off the warning commentsAndrew Morton2007-07-191-1/+4
| | | | | | | | I've been chasing these comments around this file all week. Hopefully we're straight now. Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* lockstat: core infrastructurePeter Zijlstra2007-07-191-0/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Introduce the core lock statistics code. Lock statistics provides lock wait-time and hold-time (as well as the count of corresponding contention and acquisitions events). Also, the first few call-sites that encounter contention are tracked. Lock wait-time is the time spent waiting on the lock. This provides insight into the locking scheme, that is, a heavily contended lock is indicative of a too coarse locking scheme. Lock hold-time is the duration the lock was held, this provides a reference for the wait-time numbers, so they can be put into perspective. 1) lock 2) ... do stuff .. unlock 3) The time between 1 and 2 is the wait-time. The time between 2 and 3 is the hold-time. The lockdep held-lock tracking code is reused, because it already collects locks into meaningful groups (classes), and because it is an existing infrastructure for lock instrumentation. Currently lockdep tracks lock acquisition with two hooks: lock() lock_acquire() _lock() ... code protected by lock ... unlock() lock_release() _unlock() We need to extend this with two more hooks, in order to measure contention. lock_contended() - used to measure contention events lock_acquired() - completion of the contention These are then placed the following way: lock() lock_acquire() if (!_try_lock()) lock_contended() _lock() lock_acquired() ... do locked stuff ... unlock() lock_release() _unlock() (Note: the try_lock() 'trick' is used to avoid instrumenting all platform dependent lock primitive implementations.) It is also possible to toggle the two lockdep features at runtime using: /proc/sys/kernel/prove_locking /proc/sys/kernel/lock_stat (esp. turning off the O(n^2) prove_locking functionaliy can help) [akpm@linux-foundation.org: build fixes] [akpm@linux-foundation.org: nuke unneeded ifdefs] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Ingo Molnar <mingo@elte.hu> Acked-by: Jason Baron <jbaron@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* coredump masking: bound suid_dumpable sysctlKawai, Hidehiro2007-07-191-1/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch series is version 5 of the core dump masking feature, which controls which VMAs should be dumped based on their memory types and per-process flags. I adopted most of Andrew's suggestion at the previous version. He also suggested using system call instead of /proc/<pid>/ interface, I decided to use the latter continuously because adding new system call with pid argument will give a big impact on the kernel. You can access the per-process flags via /proc/<pid>/coredump_filter interface. coredump_filter represents a bitmask of memory types, and if a bit is set, VMAs of corresponding memory type are written into a core file when the process is dumped. The bitmask is inherited from the parent process when a process is created. The original purpose is to avoid longtime system slowdown when a number of processes which share a huge shared memory are dumped at the same time. To achieve this purpose, this patch series adds an ability to suppress dumping anonymous shared memory for specified processes. In this version, three other memory types are also supported. Here are the coredump_filter bits: bit 0: anonymous private memory bit 1: anonymous shared memory bit 2: file-backed private memory bit 3: file-backed shared memory The default value of coredump_filter is 0x3. This means the new core dump routine has the same behavior as conventional behavior by default. In this version, coredump_filter bits and mm.dumpable are merged into mm.flags, and it is accessed by atomic bitops. The supported core file formats are ELF and ELF-FDPIC. ELF has been tested, but ELF-FDPIC has not been built and tested because I don't have the test environment. This patch limits a value of suid_dumpable sysctl to the range of 0 to 2. Signed-off-by: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: David Howells <dhowells@redhat.com> Cc: Hugh Dickins <hugh@veritas.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* audit: rework execve auditPeter Zijlstra2007-07-191-0/+11
| | | | | | | | | | | | | | | | | | | | | | | The purpose of audit_bprm() is to log the argv array to a userspace daemon at the end of the execve system call. Since user-space hasn't had time to run, this array is still in pristine state on the process' stack; so no need to copy it, we can just grab it from there. In order to minimize the damage to audit_log_*() copy each string into a temporary kernel buffer first. Currently the audit code requires that the full argument vector fits in a single packet. So currently it does clip the argv size to a (sysctl) limit, but only when execve auditing is enabled. If the audit protocol gets extended to allow for multiple packets this check can be removed. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ollie Wild <aaw@google.com> Cc: <linux-audit@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* PM: Integrate beeping flag with existing acpi_sleep flagsPavel Machek2007-07-191-1/+1
| | | | | | | | | | | | | Move "debug during resume from s2ram" into the variable we already use for real-mode flags to simplify code. It also closes nasty trap for the user in acpi_sleep_setup; order of parameters actually mattered there, acpi_sleep=s3_bios,s3_mode doing something different from acpi_sleep=s3_mode,s3_bios. Signed-off-by: Pavel Machek <pavel@suse.cz> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Add common orderly_poweroff()Jeremy Fitzhardinge2007-07-181-0/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | Various pieces of code around the kernel want to be able to trigger an orderly poweroff. This pulls them together into a single implementation. By default the poweroff command is /sbin/poweroff, but it can be set via sysctl: kernel/poweroff_cmd. This is split at whitespace, so it can include command-line arguments. This patch replaces four other instances of invoking either "poweroff" or "shutdown -h now": two sbus drivers, and acpi thermal management. sparc64 has its own "powerd"; still need to determine whether it should be replaced by orderly_poweroff(). Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com> Acked-by: Len Brown <lenb@kernel.org> Signed-off-by: Chris Wright <chrisw@sous-sol.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Randy Dunlap <randy.dunlap@oracle.com> Cc: Andi Kleen <ak@suse.de> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Arnd Bergmann <arnd@arndb.de> Cc: David S. Miller <davem@davemloft.net>
* proper prototype for proc_nr_files()Adrian Bunk2007-07-171-3/+1
| | | | | | | | Add a proper prototype for proc_nr_files() in include/linux/fs.h Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Allow huge page allocations to use GFP_HIGH_MOVABLEMel Gorman2007-07-171-0/+8
| | | | | | | | | | | | | | | | | | | Huge pages are not movable so are not allocated from ZONE_MOVABLE. However, as ZONE_MOVABLE will always have pages that can be migrated or reclaimed, it can be used to satisfy hugepage allocations even when the system has been running a long time. This allows an administrator to resize the hugepage pool at runtime depending on the size of ZONE_MOVABLE. This patch adds a new sysctl called hugepages_treat_as_movable. When a non-zero value is written to it, future allocations for the huge page pool will use ZONE_MOVABLE. Despite huge pages being non-movable, we do not introduce additional external fragmentation of note as huge pages are always the largest contiguous block we care about. [akpm@linux-foundation.org: various fixes] Signed-off-by: Mel Gorman <mel@csn.ul.ie> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Remove duplicate comments from sysctl.cLinus Torvalds2007-07-161-8/+0
| | | | | | | | | | | | Randy Dunlap noticed that the recent comment clarifications from Andrew had somehow gotten duplicated. Quoth Andrew: "hm, that could have been some late-night reject-fixing." Fix it up. Cc: From: Andrew Morton <akpm@linux-foundation.org> Cc: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* sysctl.c: add text telling people to use CTL_UNNUMBEREDAndrew Morton2007-07-161-1/+20
| | | | | | | | Hopefully this will help people to understand the new regime. Cc: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* vdso: print fatal signalsIngo Molnar2007-07-161-0/+9
| | | | | | | | | | | | | | | | | Add the print-fatal-signals=1 boot option and the /proc/sys/kernel/print-fatal-signals runtime switch. This feature prints some minimal information about userspace segfaults to the kernel console. This is useful to find early bootup bugs where userspace debugging is very hard. Defaults to off. [akpm@linux-foundation.org: Don't add new sysctl numbers] Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Arjan van de Ven <arjan@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* change zonelist order: zonelist order selection logicKAMEZAWA Hiroyuki2007-07-161-0/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Make zonelist creation policy selectable from sysctl/boot option v6. This patch makes NUMA's zonelist (of pgdat) order selectable. Available order are Default(automatic)/ Node-based / Zone-based. [Default Order] The kernel selects Node-based or Zone-based order automatically. [Node-based Order] This policy treats the locality of memory as the most important parameter. Zonelist order is created by each zone's locality. This means lower zones (ex. ZONE_DMA) can be used before higher zone (ex. ZONE_NORMAL) exhausion. IOW. ZONE_DMA will be in the middle of zonelist. current 2.6.21 kernel uses this. Pros. * A user can expect local memory as much as possible. Cons. * lower zone will be exhansted before higher zone. This may cause OOM_KILL. Maybe suitable if ZONE_DMA is relatively big and you never see OOM_KILL because of ZONE_DMA exhaution and you need the best locality. (example) assume 2 node NUMA. node(0) has ZONE_DMA/ZONE_NORMAL, node(1) has ZONE_NORMAL. *node(0)'s memory allocation order: node(0)'s NORMAL -> node(0)'s DMA -> node(1)'s NORMAL. *node(1)'s memory allocation order: node(1)'s NORMAL -> node(0)'s NORMAL -> node(0)'s DMA. [Zone-based order] This policy treats the zone type as the most important parameter. Zonelist order is created by zone-type order. This means lower zone never be used bofere higher zone exhaustion. IOW. ZONE_DMA will be always at the tail of zonelist. Pros. * OOM_KILL(bacause of lower zone) occurs only if the whole zones are exhausted. Cons. * memory locality may not be best. (example) assume 2 node NUMA. node(0) has ZONE_DMA/ZONE_NORMAL, node(1) has ZONE_NORMAL. *node(0)'s memory allocation order: node(0)'s NORMAL -> node(1)'s NORMAL -> node(0)'s DMA. *node(1)'s memory allocation order: node(1)'s NORMAL -> node(0)'s NORMAL -> node(0)'s DMA. bootoption "numa_zonelist_order=" and proc/sysctl is supporetd. command: %echo N > /proc/sys/vm/numa_zonelist_order Will rebuild zonelist in Node-based order. command: %echo Z > /proc/sys/vm/numa_zonelist_order Will rebuild zonelist in Zone-based order. Thanks to Lee Schermerhorn, he gives me much help and codes. [Lee.Schermerhorn@hp.com: add check_highest_zone to build_zonelists_in_zone_order] [akpm@linux-foundation.org: build fix] Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Christoph Lameter <clameter@sgi.com> Cc: Andi Kleen <ak@suse.de> Cc: "jesse.barnes@intel.com" <jesse.barnes@intel.com> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* security: Protection for exploiting null dereference using mmapEric Paris2007-07-121-0/+10
| | | | | | | | | | | | | | | | | | | | | Add a new security check on mmap operations to see if the user is attempting to mmap to low area of the address space. The amount of space protected is indicated by the new proc tunable /proc/sys/vm/mmap_min_addr and defaults to 0, preserving existing behavior. This patch uses a new SELinux security class "memprotect." Policy already contains a number of allow rules like a_t self:process * (unconfined_t being one of them) which mean that putting this check in the process class (its best current fit) would make it useless as all user processes, which we also want to protect against, would be allowed. By taking the memprotect name of the new class it will also make it possible for us to move some of the other memory protect permissions out of 'process' and into the new class next time we bump the policy version number (which I also think is a good future idea) Acked-by: Stephen Smalley <sds@tycho.nsa.gov> Acked-by: Chris Wright <chrisw@sous-sol.org> Signed-off-by: Eric Paris <eparis@redhat.com> Signed-off-by: James Morris <jmorris@namei.org>
* sched: add CFS debug sysctlsIngo Molnar2007-07-091-0/+80
| | | | | | | add CFS debug sysctls: only tweakable if SCHED_DEBUG is enabled. This allows for faster debugging of scheduler problems. Signed-off-by: Ingo Molnar <mingo@elte.hu>
* make sysctl/kernel/core_pattern and fs/exec.c agree on maximum core filename ↵Dan Aloni2007-05-171-1/+1
| | | | | | | | | | | | | size Make sysctl/kernel/core_pattern and fs/exec.c agree on maximum core filename size and change it to 128, so that extensive patterns such as '/local/cores/%e-%h-%s-%t-%p.core' won't result in truncated filename generation. Signed-off-by: Dan Aloni <da-x@monatomic.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Make vm statistics update interval configurableChristoph Lameter2007-05-091-0/+12
| | | | | | | | | | Make it configurable. Code in mm makes the vm statistics intervals independent from the cache reaper use that opportunity to make it configurable. Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* proc: maps protectionKees Cook2007-05-081-0/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | The /proc/pid/ "maps", "smaps", and "numa_maps" files contain sensitive information about the memory location and usage of processes. Issues: - maps should not be world-readable, especially if programs expect any kind of ASLR protection from local attackers. - maps cannot just be 0400 because "-D_FORTIFY_SOURCE=2 -O2" makes glibc check the maps when %n is in a *printf call, and a setuid(getuid()) process wouldn't be able to read its own maps file. (For reference see http://lkml.org/lkml/2006/1/22/150) - a system-wide toggle is needed to allow prior behavior in the case of non-root applications that depend on access to the maps contents. This change implements a check using "ptrace_may_attach" before allowing access to read the maps contents. To control this protection, the new knob /proc/sys/kernel/maps_protect has been added, with corresponding updates to the procfs documentation. [akpm@linux-foundation.org: build fixes] [akpm@linux-foundation.org: New sysctl numbers are old hat] Signed-off-by: Kees Cook <kees@outflux.net> Cc: Arjan van de Ven <arjan@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Allow reading tainted flag as userBastian Blank2007-04-241-1/+1
| | | | | | | | | | | The commit 34f5a39899f3f3e815da64f48ddb72942d86c366 restricted reading of the tainted value. The attached patch changes this back to a write-only check and restores the read behaviour of older versions. Signed-off-by: Bastian Blank <bastian@waldi.eu.org> Cc: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* sysctl: Support vdso_enabled sysctl on SH.Paul Mundt2007-03-051-1/+2
| | | | | | | All of the logic for this was already in place, we just hadn't wired it up in the sysctl table. Signed-off-by: Paul Mundt <lethal@linux-sh.org>
* [PATCH] fix the SYSCTL=n compilationAdrian Bunk2007-03-011-2/+1
| | | | | | | | | | | | | /home/bunk/linux/kernel-2.6/linux-2.6.20-mm2/kernel/sysctl.c:1411: error: conflicting types for 'register_sysctl_table' /home/bunk/linux/kernel-2.6/linux-2.6.20-mm2/include/linux/sysctl.h:1042: error: previous declaration of 'register_sysctl_table' was here make[2]: *** [kernel/sysctl.o] Error 1 Caused by commit 0b4d414714f0d2f922d39424b0c5c82ad900a381. Signed-off-by: Adrian Bunk <bunk@stusta.de> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [PATCH] sysctl: add a parent entry to ctl_table and set the parent entryEric W. Biederman2007-02-141-0/+18
| | | | | | | | | | | Add a parent entry into the ctl_table so you can walk the list of parents and find the entire path to a ctl_table entry. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Cc: Stephen Smalley <sds@tycho.nsa.gov> Cc: James Morris <jmorris@namei.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [PATCH] sysctl: reimplement the sysctl proc supportEric W. Biederman2007-02-141-182/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | With this change the sysctl inodes can be cached and nothing needs to be done when removing a sysctl table. For a cost of 2K code we will save about 4K of static tables (when we remove de from ctl_table) and 70K in proc_dir_entries that we will not allocate, or about half that on a 32bit arch. The speed feels about the same, even though we can now cache the sysctl dentries :( We get the core advantage that we don't need to have a 1 to 1 mapping between ctl table entries and proc files. Making it possible to have /proc/sys vary depending on the namespace you are in. The currently merged namespaces don't have an issue here but the network namespace under /proc/sys/net needs to have different directories depending on which network adapters are visible. By simply being a cache different directories being visible depending on who you are is trivial to implement. [akpm@osdl.org: fix uninitialised var] [akpm@osdl.org: fix ARM build] [bunk@stusta.de: make things static] Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Cc: Russell King <rmk@arm.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-24 05:21:37 +0100