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2011-02-10cap_syslog: accept CAP_SYS_ADMIN for nowLinus Torvalds
In commit ce6ada35bdf7 ("security: Define CAP_SYSLOG") Serge Hallyn introduced CAP_SYSLOG, but broke backwards compatibility by no longer accepting CAP_SYS_ADMIN as an override (it would cause a warning and then reject the operation). Re-instate CAP_SYS_ADMIN - but keeping the warning - as an acceptable capability until any legacy applications have been updated. There are apparently applications out there that drop all capabilities except for CAP_SYS_ADMIN in order to access the syslog. (This is a re-implementation of a patch by Serge, cleaning the logic up and making the code more readable) Acked-by: Serge Hallyn <serge@hallyn.com> Reviewed-by: James Morris <jmorris@namei.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-02-10watchdog, nmi: Lower the severity of error messagesDon Zickus
During boot if the hardlockup detector fails to initialize, it complains very loudly. Some failures should be expected under certain situations, ie no lapics, or resource in-use. Tone those error messages down a bit. Keep the rest at a high level. Reported-by: Paul Bolle <pebolle@tiscali.nl> Tested-by: Paul Bolle <pebolle@tiscali.nl> Signed-off-by: Don Zickus <dzickus@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <1297278153-21111-1-git-send-email-dzickus@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-02-09Merge branch 'for-linus' of git://git.kernel.dk/linux-2.6-blockLinus Torvalds
* 'for-linus' of git://git.kernel.dk/linux-2.6-block: cdrom: support devices that have check_events but not media_changed cfq-iosched: Don't wait if queue already has requests. blkio-throttle: Avoid calling blkiocg_lookup_group() for root group cfq: rename a function to give it more appropriate name cciss: make cciss_revalidate not loop through CISS_MAX_LUNS volumes unnecessarily. drivers/block/aoe/Makefile: replace the use of <module>-objs with <module>-y loop: queue_lock NULL pointer derefence in blk_throtl_exit drivers/block/Makefile: replace the use of <module>-objs with <module>-y blktrace: Don't output messages if NOTIFY isn't set.
2011-02-08tracing: Deprecate tracing_enabled for tracing_onSteven Rostedt
tracing_enabled should not be used, it is heavy weight and does not do much in helping lower the overhead. tracing_on should be used instead. Warn users to use tracing_on when tracing_enabled is used as it will soon be removed from the tracing directory. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-02-08tracing: Remove obsolete sched_switch tracerSteven Rostedt
The trace events sched_switch and sched_wakeup do the same thing as the stand alone sched_switch tracer does. It is no longer needed. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-02-08tracing: Add unstable sched clock note to the warningJiri Olsa
The warning "Delta way too big" warning might appear on a system with unstable shed clock right after the system is resumed and tracing was enabled during the suspend. Since it's not realy bug, and the unstable sched clock is working fast and reliable otherwise, Steven suggested to keep using the sched clock in any case and just to make note in the warning itself. Signed-off-by: Jiri Olsa <jolsa@redhat.com> LKML-Reference: <1296649698-6003-1-git-send-email-jolsa@redhat.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-02-08Revert "lockdep, timer: Fix del_timer_sync() annotation"Peter Zijlstra
Both attempts at trying to allow softirq usage for del_timer_sync() failed (produced bogus warnings), so revert the commit for this release: f266a5110d45: lockdep, timer: Fix del_timer_sync() annotation and try again later. Reported-by: Borislav Petkov <bp@alien8.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Yong Zhang <yong.zhang0@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> LKML-Reference: <1297174680.13327.107.camel@laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-02-07tracing/syscalls: Early terminate search for sys_ni_syscallIan Munsie
Many system calls are unimplemented and mapped to sys_ni_syscall, but at boot ftrace would still search through every syscall metadata entry for a match which wouldn't be there. This patch adds causes the search to terminate early if the system call is not mapped. Signed-off-by: Ian Munsie <imunsie@au1.ibm.com> LKML-Reference: <1296703645-18718-7-git-send-email-imunsie@au1.ibm.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-02-07tracing/syscalls: Allow arch specific syscall symbol matchingIan Munsie
Some architectures have unusual symbol names and the generic code to match the symbol name with the function name for the syscall metadata will fail. For example, symbols on PPC64 start with a period and the generic code will fail to match them. This patch moves the match logic out into a separate function which an arch can override by defining ARCH_HAS_SYSCALL_MATCH_SYM_NAME in asm/ftrace.h and implementing arch_syscall_match_sym_name. Signed-off-by: Ian Munsie <imunsie@au1.ibm.com> LKML-Reference: <1296703645-18718-5-git-send-email-imunsie@au1.ibm.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-02-07tracing/syscalls: Make arch_syscall_addr weakIan Munsie
Some architectures use non-trivial system call tables and will not work with the generic arch_syscall_addr code. For example, PowerPC64 uses a table of twin long longs. This patch makes the generic arch_syscall_addr weak to allow architectures with non-trivial system call tables to override it. Signed-off-by: Ian Munsie <imunsie@au1.ibm.com> LKML-Reference: <1296703645-18718-4-git-send-email-imunsie@au1.ibm.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-02-07tracing/syscalls: Convert redundant syscall_nr checks into WARN_ONIan Munsie
With the ftrace events now checking if the syscall_nr is valid upon initialisation it should no longer be possible to register or unregister a syscall event without a valid syscall_nr since they should not be created. This adds a WARN_ON_ONCE in the register and unregister functions to locate potential regressions in the future. Signed-off-by: Ian Munsie <imunsie@au1.ibm.com> LKML-Reference: <1296703645-18718-3-git-send-email-imunsie@au1.ibm.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-02-07tracing/syscalls: Don't add events for unmapped syscallsIan Munsie
FTRACE_SYSCALLS would create events for each and every system call, even if it had failed to map the system call's name with it's number. This resulted in a number of events being created that would not behave as expected. This could happen, for example, on architectures who's symbol names are unusual and will not match the system call name. It could also happen with system calls which were mapped to sys_ni_syscall. This patch changes the default system call number in the metadata to -1. If the system call name from the metadata is not successfully mapped to a system call number during boot, than the event initialisation routine will now return an error, preventing the event from being created. Signed-off-by: Ian Munsie <imunsie@au1.ibm.com> LKML-Reference: <1296703645-18718-2-git-send-email-imunsie@au1.ibm.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-02-07tracing/filter: Remove synchronize_sched() from __alloc_preds()Steven Rostedt
Because the filters are processed first and then activated (added to the call), we no longer need to worry about the preds of the filter in __alloc_preds() being used. As the filter that is allocating preds is not activated yet. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-02-07tracing/filter: Swap entire filter of eventsSteven Rostedt
When creating a new filter, instead of allocating the filter to the event call first and then processing the filter, it is easier to process a temporary filter and then just swap it with the call filter. By doing this, it simplifies the code. A filter is allocated and processed, when it is done, it is swapped with the call filter, synchronize_sched() is called to make sure all callers are done with the old filter (filters are called with premption disabled), and then the old filter is freed. Cc: Tom Zanussi <tzanussi@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-02-07tracing/filter: Increase the max preds to 2^14Steven Rostedt
Now that the filter logic does not require to save the pred results on the stack, we can increase the max number of preds we allow. As the preds are index by a short value, and we use the MSBs as flags we can increase the max preds to 2^14 (16384) which should be way more than enough. Cc: Tom Zanussi <tzanussi@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-02-07tracing/filter: Move MAX_FILTER_PRED to local tracing directorySteven Rostedt
The MAX_FILTER_PRED is only needed by the kernel/trace/*.c files. Move it to kernel/trace/trace.h. Cc: Tom Zanussi <tzanussi@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-02-07tracing/filter: Optimize filter by folding the treeSteven Rostedt
There are many cases that a filter will contain multiple ORs or ANDs together near the leafs. Walking up and down the tree to get to the next compare can be a waste. If there are several ORs or ANDs together, fold them into a single pred and allocate an array of the conditions that they check. This will speed up the filter by linearly walking an array and can still break out if a short circuit condition is met. Cc: Tom Zanussi <tzanussi@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-02-07tracing/filter: Check the created pred treeSteven Rostedt
Since the filter walks a tree to determine if a match is made or not, if the tree was incorrectly created, it could cause an infinite loop. Add a check to walk the entire tree before assigning it as a filter to make sure the tree is correct. Cc: Tom Zanussi <tzanussi@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-02-07tracing/filter: Optimize short ciruit checkSteven Rostedt
The test if we should break out early for OR and AND operations can be optimized by comparing the current result with (pred->op == OP_OR) That is if the result is true and the op is an OP_OR, or if the result is false and the op is not an OP_OR (thus an OP_AND) we can break out early in either case. Otherwise we continue processing. Cc: Tom Zanussi <tzanussi@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-02-07tracing/filter: Use a tree instead of stack for filter_match_preds()Steven Rostedt
Currently the filter_match_preds() requires a stack to push and pop the preds to determine if the filter matches the record or not. This has two drawbacks: 1) It requires a stack to store state information. As this is done in fast paths we can't allocate the storage for this stack, and we can't use a global as it must be re-entrant. The stack is stored on the kernel stack and this greatly limits how many preds we may allow. 2) All conditions are calculated even when a short circuit exists. a || b will always calculate a and b even though a was determined to be true. Using a tree we can walk a constant structure that will save the state as we go. The algorithm is simply: pred = root; do { switch (move) { case MOVE_DOWN: if (OR or AND) { pred = left; continue; } if (pred == root) break; match = pred->fn(); pred = pred->parent; move = left child ? MOVE_UP_FROM_LEFT : MOVE_UP_FROM_RIGHT; continue; case MOVE_UP_FROM_LEFT: /* Only OR or AND can be a parent */ if (match && OR || !match && AND) { /* short circuit */ if (pred == root) break; pred = pred->parent; move = left child ? MOVE_UP_FROM_LEFT : MOVE_UP_FROM_RIGHT; continue; } pred = pred->right; move = MOVE_DOWN; continue; case MOVE_UP_FROM_RIGHT: if (pred == root) break; pred = pred->parent; move = left child ? MOVE_UP_FROM_LEFT : MOVE_UP_FROM_RIGHT; continue; } done = 1; } while (!done); This way there's no strict limit to how many preds we allow and it also will short circuit the logical operations when possible. Cc: Tom Zanussi <tzanussi@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-02-07tracing/filter: Free pred array on disabling of filterSteven Rostedt
When a filter is disabled, free the preds. Cc: Tom Zanussi <tzanussi@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-02-07tracing/filter: Allocate the preds in an arraySteven Rostedt
Currently we allocate an array of pointers to filter_preds, and then allocate a separate filter_pred for each item in the array. This adds slight overhead in the filters as it needs to derefernce twice to get to the op condition. Allocating the preds themselves in a single array removes a dereference as well as helps on the cache footprint. Cc: Tom Zanussi <tzanussi@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-02-07tracing/filter: Call synchronize_sched() just once for system filtersSteven Rostedt
By separating out the reseting of the filter->n_preds to zero from the reallocation of preds for the filter, we can reset groups of filters first, call synchronize_sched() just once, and then reallocate each of the filters in the system group. Cc: Tom Zanussi <tzanussi@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-02-07tracing/filter: Dynamically allocate predsSteven Rostedt
For every filter that is made, we create predicates to hold every operation within the filter. We have a max of 32 predicates that we can hold. Currently, we allocate all 32 even if we only need to use one. Part of the reason we do this is that the filter can be used at any moment by any event. Fortunately, the filter is only used with preemption disabled. By reseting the count of preds used "n_preds" to zero, then performing a synchronize_sched(), we can safely free and reallocate a new array of preds. Cc: Tom Zanussi <tzanussi@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-02-07tracing/filter: Move OR and AND logic out of fn() methodSteven Rostedt
The ops OR and AND act different from the other ops, as they are the only ones to take other ops as their arguements. These ops als change the logic of the filter_match_preds. By removing the OR and AND fn's we can also remove the val1 and val2 that is passed to all other fn's and are unused. Cc: Tom Zanussi <tzanussi@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-02-07tracing/filter: Have no filter return a matchSteven Rostedt
The n_preds field of a file can change at anytime, and even can become zero, just as the filter is about to be processed by an event. In the case that is zero on entering the filter, return 1, telling the caller the event matchs and should be trace. Also use a variable and assign it with ACCESS_ONCE() such that the count stays consistent within the function. Cc: Tom Zanussi <tzanussi@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-02-07CRED: Fix memory and refcount leaks upon security_prepare_creds() failureTetsuo Handa
In prepare_kernel_cred() since 2.6.29, put_cred(new) is called without assigning new->usage when security_prepare_creds() returned an error. As a result, memory for new and refcount for new->{user,group_info,tgcred} are leaked because put_cred(new) won't call __put_cred() unless old->usage == 1. Fix these leaks by assigning new->usage (and new->subscribers which was added in 2.6.32) before calling security_prepare_creds(). Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-02-07CRED: Fix BUG() upon security_cred_alloc_blank() failureTetsuo Handa
In cred_alloc_blank() since 2.6.32, abort_creds(new) is called with new->security == NULL and new->magic == 0 when security_cred_alloc_blank() returns an error. As a result, BUG() will be triggered if SELinux is enabled or CONFIG_DEBUG_CREDENTIALS=y. If CONFIG_DEBUG_CREDENTIALS=y, BUG() is called from __invalid_creds() because cred->magic == 0. Failing that, BUG() is called from selinux_cred_free() because selinux_cred_free() is not expecting cred->security == NULL. This does not affect smack_cred_free(), tomoyo_cred_free() or apparmor_cred_free(). Fix these bugs by (1) Set new->magic before calling security_cred_alloc_blank(). (2) Handle null cred->security in creds_are_invalid() and selinux_cred_free(). Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-02-07tracing/kprobes: Add bitfield typeMasami Hiramatsu
Add bitfield type for tracing arguments on kprobe-tracer. The syntax of a bitfield type is: b<bit-size>@<bit-offset>/<container-size> e.g. Accessing 2 bits-width field with 4 bits-offset in 32 bits-width data at 4 bytes offseted from the address pointed by AX register: +4(%ax):b2@4/32 Since the width of container data depends on the arch, so I just added the container-size at the end. Cc: 2nddept-manager@sdl.hitachi.co.jp Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Steven Rostedt <rostedt@goodmis.org> LKML-Reference: <20110204125205.9507.11363.stgit@ltc236.sdl.hitachi.co.jp> Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2011-02-07tracing/kprobes: Support longer (>128 bytes) commandMasami Hiramatsu
Expand command line buffer of kprobe-tracer to 4096 bytes. Reported-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net> Cc: 2nddept-manager@sdl.hitachi.co.jp Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Steven Rostedt <rostedt@goodmis.org> LKML-Reference: <20110204125159.9507.20895.stgit@ltc236.sdl.hitachi.co.jp> Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2011-02-07tracing/kprobes: Cleanup strict_strtol() using codeMasami Hiramatsu
Since strict_strtol() accepts minus digits started with '-', it doesn't need to invert after converting. Cc: 2nddept-manager@sdl.hitachi.co.jp Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Steven Rostedt <rostedt@goodmis.org> LKML-Reference: <20110204125153.9507.49335.stgit@ltc236.sdl.hitachi.co.jp> Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2011-02-07Merge branch 'linus' into perf/coreIngo Molnar
Merge reason: Pick up perf fixes that are now upstream Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-02-06Merge branch 'timers-fixes-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: lockdep, timer: Fix del_timer_sync() annotation RTC: Prevents a division by zero in kernel code.
2011-02-04Merge branch 'tip/perf/urgent-2' of ↵Ingo Molnar
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into perf/urgent
2011-02-04lockdep, timer: Fix del_timer_sync() annotationPeter Zijlstra
Calling local_bh_enable() will want to actually start processing softirqs, which isn't a good idea since this can get called with IRQs disabled. Cure this by using _local_bh_enable() which doesn't start processing softirqs, and use raw_local_irq_save() to avoid any softirqs from happening without letting lockdep think IRQs are in fact disabled. Reported-by: Nick Bowler <nbowler@elliptictech.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Reviewed-by: Yong Zhang <yong.zhang0@gmail.com> LKML-Reference: <20110203141548.039540914@chello.nl> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-02-03Merge branch 'irq-fixes-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'irq-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: genirq: Prevent irq storm on migration
2011-02-03Merge branch 'sched-fixes-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: sched: Fix update_curr_rt() sched, docs: Update schedstats documentation to version 15
2011-02-03Merge branch 'perf-fixes-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: perf: Fix reading in perf_event_read() watchdog: Don't change watchdog state on read of sysctl watchdog: Fix sysctl consistency watchdog: Fix broken nowatchdog logic perf: Fix Pentium4 raw event validation perf: Fix alloc_callchain_buffers()
2011-02-03tracing: Replace syscall_meta_data struct array with pointer arraySteven Rostedt
Currently the syscall_meta structures for the syscall tracepoints are placed in the __syscall_metadata section, and at link time, the linker makes one large array of all these syscall metadata structures. On boot up, this array is read (much like the initcall sections) and the syscall data is processed. The problem is that there is no guarantee that gcc will place complex structures nicely together in an array format. Two structures in the same file may be placed awkwardly, because gcc has no clue that they are suppose to be in an array. A hack was used previous to force the alignment to 4, to pack the structures together. But this caused alignment issues with other architectures (sparc). Instead of packing the structures into an array, the structures' addresses are now put into the __syscall_metadata section. As pointers are always the natural alignment, gcc should always pack them tightly together (otherwise initcall, extable, etc would also fail). By having the pointers to the structures in the section, we can still iterate the trace_events without causing unnecessary alignment problems with other architectures, or depending on the current behaviour of gcc that will likely change in the future just to tick us kernel developers off a little more. The __syscall_metadata section is also moved into the .init.data section as it is now only needed at boot up. Suggested-by: David Miller <davem@davemloft.net> Acked-by: David S. Miller <davem@davemloft.net> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-02-03tracepoints: Fix section alignment using pointer arrayMathieu Desnoyers
Make the tracepoints more robust, making them solid enough to handle compiler changes by not relying on anything based on compiler-specific behavior with respect to structure alignment. Implement an approach proposed by David Miller: use an array of const pointers to refer to the individual structures, and export this pointer array through the linker script rather than the structures per se. It will consume 32 extra bytes per tracepoint (24 for structure padding and 8 for the pointers), but are less likely to break due to compiler changes. History: commit 7e066fb8 tracepoints: add DECLARE_TRACE() and DEFINE_TRACE() added the aligned(32) type and variable attribute to the tracepoint structures to deal with gcc happily aligning statically defined structures on 32-byte multiples. One attempt was to use a 8-byte alignment for tracepoint structures by applying both the variable and type attribute to tracepoint structures definitions and declarations. It worked fine with gcc 4.5.1, but broke with gcc 4.4.4 and 4.4.5. The reason is that the "aligned" attribute only specify the _minimum_ alignment for a structure, leaving both the compiler and the linker free to align on larger multiples. Because tracepoint.c expects the structures to be placed as an array within each section, up-alignment cause NULL-pointer exceptions due to the extra unexpected padding. (this patch applies on top of -tip) Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Acked-by: David S. Miller <davem@davemloft.net> LKML-Reference: <20110126222622.GA10794@Krystal> CC: Frederic Weisbecker <fweisbec@gmail.com> CC: Ingo Molnar <mingo@elte.hu> CC: Thomas Gleixner <tglx@linutronix.de> CC: Andrew Morton <akpm@linux-foundation.org> CC: Peter Zijlstra <peterz@infradead.org> CC: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-02-03sched: Fix update_curr_rt()Peter Zijlstra
cpu_stopper_thread() migration_cpu_stop() __migrate_task() deactivate_task() dequeue_task() dequeue_task_rq() update_curr_rt() Will call update_curr_rt() on rq->curr, which at that time is rq->stop. The problem is that rq->stop.prio matches an RT prio and thus falsely assumes its a rt_sched_class task. Reported-Debuged-Tested-Acked-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Cc: stable@kernel.org # .37 Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-02-03perf: Fix reading in perf_event_read()Peter Zijlstra
It is quite possible for the event to have been disabled between perf_event_read() sending the IPI and the CPU servicing the IPI and calling __perf_event_read(), hence revalidate the state. Reported-by: Stephane Eranian <eranian@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-02-03perf: Cure task_oncpu_function_call() racesPeter Zijlstra
Oleg reported that on architectures with __ARCH_WANT_INTERRUPTS_ON_CTXSW the IPI from task_oncpu_function_call() can land before perf_event_task_sched_in() and cause interesting situations for eg. perf_install_in_context(). This patch reworks the task_oncpu_function_call() interface to give a more usable primitive as well as rework all its users to hopefully be more obvious as well as remove the races. While looking at the code I also found a number of races against perf_event_task_sched_out() which can flip contexts between tasks so plug those too. Reported-and-reviewed-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-02-02tracing: Replace trace_event struct array with pointer arraySteven Rostedt
Currently the trace_event structures are placed in the _ftrace_events section, and at link time, the linker makes one large array of all the trace_event structures. On boot up, this array is read (much like the initcall sections) and the events are processed. The problem is that there is no guarantee that gcc will place complex structures nicely together in an array format. Two structures in the same file may be placed awkwardly, because gcc has no clue that they are suppose to be in an array. A hack was used previous to force the alignment to 4, to pack the structures together. But this caused alignment issues with other architectures (sparc). Instead of packing the structures into an array, the structures' addresses are now put into the _ftrace_event section. As pointers are always the natural alignment, gcc should always pack them tightly together (otherwise initcall, extable, etc would also fail). By having the pointers to the structures in the section, we can still iterate the trace_events without causing unnecessary alignment problems with other architectures, or depending on the current behaviour of gcc that will likely change in the future just to tick us kernel developers off a little more. The _ftrace_event section is also moved into the .init.data section as it is now only needed at boot up. Suggested-by: David Miller <davem@davemloft.net> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-02-02genirq: Prevent irq storm on migrationThomas Gleixner
move_native_irq() masks and unmasks the interrupt line unconditionally, but the interrupt line might be masked due to a threaded oneshot handler in progress. Unmasking the line in that case can lead to interrupt storms. Observed on PREEMPT_RT. Originally-from: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@kernel.org
2011-01-31watchdog: Don't change watchdog state on read of sysctlMarcin Slusarz
Signed-off-by: Marcin Slusarz <marcin.slusarz@gmail.com> [ add {}'s to fix a warning ] Signed-off-by: Don Zickus <dzickus@redhat.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: <stable@kernel.org> LKML-Reference: <1296230433-6261-3-git-send-email-dzickus@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-01-31watchdog: Fix sysctl consistencyMarcin Slusarz
If it was not possible to enable watchdog for any cpu, switch watchdog_enabled back to 0, because it's visible via kernel.watchdog sysctl. Signed-off-by: Marcin Slusarz <marcin.slusarz@gmail.com> Signed-off-by: Don Zickus <dzickus@redhat.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: <stable@kernel.org> LKML-Reference: <1296230433-6261-2-git-send-email-dzickus@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-01-31watchdog: Fix broken nowatchdog logicMarcin Slusarz
Passing nowatchdog to kernel disables 2 things: creation of watchdog threads AND initialization of percpu watchdog_hrtimer. As hrtimers are initialized only at boot it's not possible to enable watchdog later - for me all watchdog threads started to eat 100% of CPU time, but they could just crash. Additionally, even if these threads would start properly, watchdog_disable_all_cpus was guarded by no_watchdog check, so you couldn't disable watchdog. To fix this, remove no_watchdog variable and use already existing watchdog_enabled variable. Signed-off-by: Marcin Slusarz <marcin.slusarz@gmail.com> [ removed another no_watchdog instance ] Signed-off-by: Don Zickus <dzickus@redhat.com> Cc: Stephane Eranian <eranian@google.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: <stable@kernel.org> LKML-Reference: <1296230433-6261-1-git-send-email-dzickus@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-01-31Fix prlimit64 for suid/sgid processesKacper Kornet
Since check_prlimit_permission always fails in the case of SUID/GUID processes, such processes are not able to read or set their own limits. This commit changes this by assuming that process can always read/change its own limits. Signed-off-by: Kacper Kornet <kornet@camk.edu.pl> Acked-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-28Merge branch 'sched-fixes-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: sched: Use rq->clock_task instead of rq->clock for correctly maintaining load averages sched: Fix/remove redundant cfs_rq checks sched: Fix sign under-flows in wake_affine