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2010-11-19Revert "kernel: make /proc/kallsyms mode 400 to reduce ease of attacking"Linus Torvalds1-1/+1
This reverts commit 59365d136d205cc20fe666ca7f89b1c5001b0d5a. It turns out that this can break certain existing user land setups. Quoth Sarah Sharp: "On Wednesday, I updated my branch to commit 460781b from linus' tree, and my box would not boot. klogd segfaulted, which stalled the whole system. At first I thought it actually hung the box, but it continued booting after 5 minutes, and I was able to log in. It dropped back to the text console instead of the graphical bootup display for that period of time. dmesg surprisingly still works. I've bisected the problem down to this commit (commit 59365d136d205cc20fe666ca7f89b1c5001b0d5a) The box is running klogd 1.5.5ubuntu3 (from Jaunty). Yes, I know that's old. I read the bit in the commit about changing the permissions of kallsyms after boot, but if I can't boot that doesn't help." So let's just keep the old default, and encourage distributions to do the "chmod -r /proc/kallsyms" in their bootup scripts. This is not worth a kernel option to change default behavior, since it's so easily done in user space. Reported-and-bisected-by: Sarah Sharp <sarah.a.sharp@linux.intel.com> Cc: Marcus Meissner <meissner@suse.de> Cc: Tejun Heo <tj@kernel.org> Cc: Eugene Teo <eugeneteo@kernel.org> Cc: Jesper Juhl <jj@chaosbits.net> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-11-18Merge branch 'for_linus' of ↵Linus Torvalds1-10/+11
git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/linux-2.6-kgdb * 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/linux-2.6-kgdb: kgdb,ppc: Fix regression in evr register handling kgdb,x86: fix regression in detach handling kdb: fix crash when KDB_BASE_CMD_MAX is exceeded kdb: fix memory leak in kdb_main.c
2010-11-18irq_work: Drop cmpxchg() resultSergio Aguirre1-1/+3
The compiler warned us about: kernel/irq_work.c: In function 'irq_work_run': kernel/irq_work.c:148: warning: value computed is not used Dropping the cmpxchg() result is indeed weird, but correct - so annotate away the warning. Signed-off-by: Sergio Aguirre <saaguirre@ti.com> Cc: Huang Ying <ying.huang@intel.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Kyle McMartin <kyle@mcmartin.ca> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1289930567-17828-1-git-send-email-saaguirre@ti.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-18perf: Fix owner-list vs exitPeter Zijlstra1-12/+51
Oleg noticed that a perf-fd keeping a reference on the creating task leads to a few funny side effects. There's two different aspects to this: - kernel based perf-events, these should not take out a reference on the creating task and appear on the task's event list since they're not bound to fds nor visible to userspace. - fork() and pthread_create(), these can lead to the creating task dying (and thus the task's event-list becomming useless) but keeping the list and ref alive until the event is closed. Combined they lead to malfunction of the ptrace hw_tracepoints. Cure this by not considering kernel based perf_events for the owner-list and destroying the owner-list when the owner dies. Reported-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Oleg Nesterov <oleg@redhat.com> LKML-Reference: <1289576883.2084.286.camel@laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-18sched: Fix idle balancingNikhil Rao1-1/+3
An earlier commit reverts idle balancing throttling reset to fix a 30% regression in volanomark throughput. We still need to reset idle_stamp when we pull a task in newidle balance. Reported-by: Alex Shi <alex.shi@intel.com> Signed-off-by: Nikhil Rao <ncrao@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1290022924-3548-1-git-send-email-ncrao@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-18sched: Fix volanomark performance regressionAlex Shi1-4/+0
Commit fab4762 triggers excessive idle balancing, causing a ~30% loss in volanomark throughput. Remove idle balancing throttle reset. Originally-by: Alex Shi <alex.shi@intel.com> Signed-off-by: Mike Galbraith <efault@gmx.de> Acked-by: Nikhil Rao <ncrao@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1289928732.5169.211.camel@maggy.simson.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-18Merge branch 'perf/urgent' of ↵Ingo Molnar2-2/+7
git://git.kernel.org/pub/scm/linux/kernel/git/frederic/random-tracing into perf/urgent
2010-11-18Merge branch 'tip/perf/urgent-3' of ↵Ingo Molnar2-0/+31
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into perf/urgent
2010-11-17kdb: fix crash when KDB_BASE_CMD_MAX is exceededJovi Zhang1-4/+4
When the number of dyanmic kdb commands exceeds KDB_BASE_CMD_MAX, the kernel will fault. Signed-off-by: Jovi Zhang <bookjovi@gmail.com> Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
2010-11-17kdb: fix memory leak in kdb_main.cJovi Zhang1-6/+7
Call kfree in the error path as well as the success path in kdb_ll(). Signed-off-by: Jovi Zhang <bookjovi@gmail.com> Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
2010-11-17BKL: remove extraneous #include <smp_lock.h>Arnd Bergmann1-1/+0
The big kernel lock has been removed from all these files at some point, leaving only the #include. Remove this too as a cleanup. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-11-16kernel: make /proc/kallsyms mode 400 to reduce ease of attackingMarcus Meissner1-1/+1
Making /proc/kallsyms readable only for root by default makes it slightly harder for attackers to write generic kernel exploits by removing one source of knowledge where things are in the kernel. This is the second submit, discussion happened on this on first submit and mostly concerned that this is just one hole of the sieve ... but one of the bigger ones. Changing the permissions of at least System.map and vmlinux is also required to fix the same set, but a packaging issue. Target of this starter patch and follow ups is removing any kind of kernel space address information leak from the kernel. [ Side note: the default of root-only reading is the "safe" value, and it's easy enough to then override at any time after boot. The /proc filesystem allows root to change the permissions with a regular chmod, so you can "revert" this at run-time by simply doing chmod og+r /proc/kallsyms as root if you really want regular users to see the kernel symbols. It does help some tools like "perf" figure them out without any setup, so it may well make sense in some situations. - Linus ] Signed-off-by: Marcus Meissner <meissner@suse.de> Acked-by: Tejun Heo <tj@kernel.org> Acked-by: Eugene Teo <eugeneteo@kernel.org> Reviewed-by: Jesper Juhl <jj@chaosbits.net> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-11-16Merge branch 'sched-fixes-for-linus' of ↵Linus Torvalds3-22/+61
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 cross-sched-class wakeup preemption sched: Fix runnable condition for stoptask sched: Use group weight, idle cpu metrics to fix imbalances during idle
2010-11-16Merge branch 'pm-fixes' of ↵Linus Torvalds2-2/+6
git://git.kernel.org/pub/scm/linux/kernel/git/rafael/suspend-2.6 * 'pm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/suspend-2.6: PM / PM QoS: Fix reversed min and max PM / OPP: Hide OPP configuration when SoCs do not provide an implementation PM: Allow devices to be removed during late suspend and early resume
2010-11-16Merge branch 'futexes-for-linus' of ↵Linus Torvalds2-2/+4
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'futexes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: futex: Address compiler warnings in exit_robust_list
2010-11-16Merge branch 'for-linus' of git://git390.marist.edu/pub/scm/linux-2.6Linus Torvalds1-1/+1
* 'for-linus' of git://git390.marist.edu/pub/scm/linux-2.6: [S390] kprobes: Fix the return address of multiple kretprobes [S390] kprobes: disable interrupts throughout [S390] ftrace: build without frame pointers on s390 [S390] mm: add devmem_is_allowed() for STRICT_DEVMEM checking [S390] vmlogrdr: purge after recording is switched off [S390] cio: fix incorrect ccw_device_init_count [S390] tape: add medium state notifications [S390] fix get_user_pages_fast
2010-11-16kernel/sysctl.c: Fix build failure with !CONFIG_PRINTKJoe Perches1-1/+1
Sigh... Signed-off-by: Joe Perches <joe@perches.com> Acked-by: Eric Paris <eparis@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-11-15capabilities/syslog: open code cap_syslog logic to fix build failureEric Paris1-1/+14
The addition of CONFIG_SECURITY_DMESG_RESTRICT resulted in a build failure when CONFIG_PRINTK=n. This is because the capabilities code which used the new option was built even though the variable in question didn't exist. The patch here fixes this by moving the capabilities checks out of the LSM and into the caller. All (known) LSMs should have been calling the capabilities hook already so it actually makes the code organization better to eliminate the hook altogether. Signed-off-by: Eric Paris <eparis@redhat.com> Acked-by: James Morris <jmorris@namei.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-11-15PM / PM QoS: Fix reversed min and maxColin Cross1-2/+2
pm_qos_get_value had min and max reversed, causing all pm_qos requests to have no effect. Signed-off-by: Colin Cross <ccross@android.com> Acked-by: mark <markgross@thegnar.org> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Cc: stable@kernel.org
2010-11-12tracing: Fix recursive user stack traceSteven Rostedt1-0/+19
The user stack trace can fault when examining the trace. Which would call the do_page_fault handler, which would trace again, which would do the user stack trace, which would fault and call do_page_fault again ... Thus this is causing a recursive bug. We need to have a recursion detector here. [ Resubmitted by Jiri Olsa ] [ Eric Dumazet recommended using __this_cpu_* instead of __get_cpu_* ] Cc: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: Jiri Olsa <jolsa@redhat.com> LKML-Reference: <1289390172-9730-3-git-send-email-jolsa@redhat.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-11-12Merge branch 'for-linus' of git://git.kernel.dk/linux-2.6-blockLinus Torvalds1-4/+0
* 'for-linus' of git://git.kernel.dk/linux-2.6-block: (27 commits) block: remove unused copy_io_context() Documentation: remove anticipatory scheduler info block: remove REQ_HARDBARRIER ioprio: rcu_read_lock/unlock protect find_task_by_vpid call (V2) ioprio: fix RCU locking around task dereference block: ioctl: fix information leak to userland block: read i_size with i_size_read() cciss: fix proc warning on attempt to remove non-existant directory bio: take care not overflow page count when mapping/copying user data block: limit vec count in bio_kmalloc() and bio_alloc_map_data() block: take care not to overflow when calculating total iov length block: check for proper length of iov entries in blk_rq_map_user_iov() cciss: remove controllers supported by hpsa cciss: use usleep_range not msleep for small sleeps cciss: limit commands allocated on reset_devices cciss: Use kernel provided PCI state save and restore functions cciss: fix board status waiting code drbd: Removed checks for REQ_HARDBARRIER on incomming BIOs drbd: REQ_HARDBARRIER -> REQ_FUA transition for meta data accesses drbd: Removed the BIO_RW_BARRIER support form the receiver/epoch code ...
2010-11-12Merge branch 'perf-fixes-for-linus' of ↵Linus Torvalds1-8/+34
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, amd: Use kmalloc_node(,__GFP_ZERO) for northbridge structure allocation perf_events: Fix time tracking in samples perf trace: update usage perf trace: update Documentation with new perf trace variants perf trace: live-mode command-line cleanup perf trace record: handle commands correctly perf record: make the record options available outside perf record perf trace scripting: remove system-wide param from shell scripts perf trace scripting: fix some small memory leaks and missing error checks perf: Fix usages of profile_cpu in builtin-top.c to use cpu_list perf, ui: Eliminate stack-smashing protection compiler complaint
2010-11-12Restrict unprivileged access to kernel syslogDan Rosenberg2-0/+15
The kernel syslog contains debugging information that is often useful during exploitation of other vulnerabilities, such as kernel heap addresses. Rather than futilely attempt to sanitize hundreds (or thousands) of printk statements and simultaneously cripple useful debugging functionality, it is far simpler to create an option that prevents unprivileged users from reading the syslog. This patch, loosely based on grsecurity's GRKERNSEC_DMESG, creates the dmesg_restrict sysctl. When set to "0", the default, no restrictions are enforced. When set to "1", only users with CAP_SYS_ADMIN can read the kernel syslog via dmesg(8) or other mechanisms. [akpm@linux-foundation.org: explain the config option in kernel.txt] Signed-off-by: Dan Rosenberg <drosenberg@vsecurity.com> Acked-by: Ingo Molnar <mingo@elte.hu> Acked-by: Eugene Teo <eugeneteo@kernel.org> Acked-by: Kees Cook <kees.cook@canonical.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-11-12latencytop: fix per task accumulatorKen Chen1-9/+8
Per task latencytop accumulator prematurely terminates due to erroneous placement of latency_record_count. It should be incremented whenever a new record is allocated instead of increment on every latencytop event. Also fix search iterator to only search known record events instead of blindly searching all pre-allocated space. Signed-off-by: Ken Chen <kenchen@google.com> Reviewed-by: Arjan van de Ven <arjan@infradead.org> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-11-12kernel/range.c: fix clean_sort_range() for the case of full arrayAlexey Khoroshilov1-1/+1
clean_sort_range() should return a number of nonempty elements of range array, but if the array is full clean_sort_range() returns 0. The problem is that the number of nonempty elements is evaluated by finding the first empty element of the array. If there is no such element it returns an initial value of local variable nr_range that is zero. The fix is trivial: it changes initial value of nr_range to size of the array. The bug can lead to loss of information regarding all ranges, since typically returned value of clean_sort_range() is considered as an actual number of ranges in the array after a series of add/subtract operations. Found by Analytical Verification project of Linux Verification Center (linuxtesting.org), thanks to Alexander Kolosov. Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru> Cc: Yinghai Lu <yinghai@kernel.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-11-12perf,hw_breakpoint: Initialize hardware api earlierJason Wessel2-2/+7
When using early debugging, the kernel does not initialize the hw_breakpoint API early enough and causes the late initialization of the kernel debugger to fail. The boot arguments are: earlyprintk=vga ekgdboc=kbd kgdbwait Then simply type "go" at the kdb prompt and boot. The kernel will later emit the message: kgdb: Could not allocate hwbreakpoints And at that point the kernel debugger will cease to work correctly. The solution is to initialize the hw_breakpoint at the same time that all the other perf call backs are initialized instead of using a core_initcall() initialization which happens well after the kernel debugger can make use of hardware breakpoints. Signed-off-by: Jason Wessel <jason.wessel@windriver.com> CC: Frederic Weisbecker <fweisbec@gmail.com> CC: Ingo Molnar <mingo@elte.hu> CC: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <4CD3396D.1090308@windriver.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2010-11-11sched: Fix cross-sched-class wakeup preemptionPeter Zijlstra3-18/+27
Instead of dealing with sched classes inside each check_preempt_curr() implementation, pull out this logic into the generic wakeup preemption path. This fixes a hang in KVM (and others) where we are waiting for the stop machine thread to run ... Reported-by: Markus Trippelsdorf <markus@trippelsdorf.de> Tested-by: Marcelo Tosatti <mtosatti@redhat.com> Tested-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1288891946.2039.31.camel@laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-10tracing: Fix module use of trace_bprintk()Steven Rostedt1-0/+12
On use of trace_printk() there's a macro that determines if the format is static or a variable. If it is static, it defaults to __trace_bprintk() otherwise it uses __trace_printk(). A while ago, Lai Jiangshan added __trace_bprintk(). In that patch, we discussed a way to allow modules to use it. The difference between __trace_bprintk() and __trace_printk() is that for faster processing, just the format and args are stored in the trace instead of running it through a sprintf function. In order to do this, the format used by the __trace_bprintk() had to be persistent. See commit 1ba28e02a18cbdbea123836f6c98efb09cbf59ec The problem comes with trace_bprintk() where the module is unloaded. The pointer left in the buffer is still pointing to the format. To solve this issue, the formats in the module were copied into kernel core. If the same format was used, they would use the same copy (to prevent memory leak). This all worked well until we tried to merge everything. At the time this was written, Lai Jiangshan, Frederic Weisbecker, Ingo Molnar and myself were all touching the same code. When this was merged, we lost the part of it that was in module.c. This kept out the copying of the formats and unloading the module could cause bad pointers left in the ring buffer. This patch adds back (with updates required for current kernel) the module code that sets up the necessary pointers. Cc: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-11-11PM / OPP: Hide OPP configuration when SoCs do not provide an implementationMark Brown1-0/+4
Since the OPP API is only useful with an appropraite SoC-specific implementation there is no point in offering the ability to enable the API on general systems. Provide an ARCH_HAS OPP Kconfig symbol which masks out the option unless selected by an implementation. Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Acked-by: Nishanth Menon <nm@ti.com> Acked-by: Kevin Hilman <khilman@deeprootsystems.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2010-11-10sched: Fix runnable condition for stoptaskPeter Zijlstra1-1/+1
Heiko reported that the TASK_RUNNING check is not sufficient for CONFIG_PREEMPT=y since we can get preempted with !TASK_RUNNING. He suggested adding a ->se.on_rq test to the existing TASK_RUNNING one, however TASK_RUNNING will always have ->se.on_rq, so we might as well reduce that to a single test. [ stop tasks should never get preempted, but its good to handle this case correctly should this ever happen ] Reported-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-10sched: Use group weight, idle cpu metrics to fix imbalances during idleSuresh Siddha2-3/+33
Currently we consider a sched domain to be well balanced when the imbalance is less than the domain's imablance_pct. As the number of cores and threads are increasing, current values of imbalance_pct (for example 25% for a NUMA domain) are not enough to detect imbalances like: a) On a WSM-EP system (two sockets, each having 6 cores and 12 logical threads), 24 cpu-hogging tasks get scheduled as 13 on one socket and 11 on another socket. Leading to an idle HT cpu. b) On a hypothetial 2 socket NHM-EX system (each socket having 8 cores and 16 logical threads), 16 cpu-hogging tasks can get scheduled as 9 on one socket and 7 on another socket. Leaving one core in a socket idle whereas in another socket we have a core having both its HT siblings busy. While this issue can be fixed by decreasing the domain's imbalance_pct (by making it a function of number of logical cpus in the domain), it can potentially cause more task migrations across sched groups in an overloaded case. Fix this by using imbalance_pct only during newly_idle and busy load balancing. And during idle load balancing, check if there is an imbalance in number of idle cpu's across the busiest and this sched_group or if the busiest group has more tasks than its weight that the idle cpu in this_group can pull. Reported-by: Nikhil Rao <ncrao@google.com> Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1284760952.2676.11.camel@sbsiddha-MOBL3.sc.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-10perf_events: Fix time tracking in samplesStephane Eranian1-8/+34
This patch corrects time tracking in samples. Without this patch both time_enabled and time_running are bogus when user asks for PERF_SAMPLE_READ. One uses PERF_SAMPLE_READ to sample the values of other counters in each sample. Because of multiplexing, it is necessary to know both time_enabled, time_running to be able to scale counts correctly. In this second version of the patch, we maintain a shadow copy of ctx->time which allows us to compute ctx->time without calling update_context_time() from NMI context. We avoid the issue that update_context_time() must always be called with ctx->lock held. We do not keep shadow copies of the other event timings because if the lead event is overflowing then it is active and thus it's been scheduled in via event_sched_in() in which case neither tstamp_stopped, tstamp_running can be modified. This timing logic only applies to samples when PERF_SAMPLE_READ is used. Note that this patch does not address timing issues related to sampling inheritance between tasks. This will be addressed in a future patch. With this patch, the libpfm4 example task_smpl now reports correct counts (shown on 2.4GHz Core 2): $ task_smpl -p 2400000000 -e unhalted_core_cycles:u,instructions_retired:u,baclears noploop 5 noploop for 5 seconds IIP:0x000000004006d6 PID:5596 TID:5596 TIME:466,210,211,430 STREAM_ID:33 PERIOD:2,400,000,000 ENA=1,010,157,814 RUN=1,010,157,814 NR=3 2,400,000,254 unhalted_core_cycles:u (33) 2,399,273,744 instructions_retired:u (34) 53,340 baclears (35) Signed-off-by: Stephane Eranian <eranian@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <4cc6e14b.1e07e30a.256e.5190@mx.google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-10block: remove REQ_HARDBARRIERChristoph Hellwig1-4/+0
REQ_HARDBARRIER is dead now, so remove the leftovers. What's left at this point is: - various checks inside the block layer. - sanity checks in bio based drivers. - now unused bio_empty_barrier helper. - Xen blockfront use of BLKIF_OP_WRITE_BARRIER - it's dead for a while, but Xen really needs to sort out it's barrier situaton. - setting of ordered tags in uas - dead code copied from old scsi drivers. - scsi different retry for barriers - it's dead and should have been removed when flushes were converted to FS requests. - blktrace handling of barriers - removed. Someone who knows blktrace better should add support for REQ_FLUSH and REQ_FUA, though. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-11-10futex: Address compiler warnings in exit_robust_listDarren Hart2-2/+4
Since commit 1dcc41bb (futex: Change 3rd arg of fetch_robust_entry() to unsigned int*) some gcc versions decided to emit the following warning: kernel/futex.c: In function ‘exit_robust_list’: kernel/futex.c:2492: warning: ‘next_pi’ may be used uninitialized in this function The commit did not introduce the warning as gcc should have warned before that commit as well. It's just gcc being silly. The code path really can't result in next_pi being unitialized (or should not), but let's keep the build clean. Annotate next_pi as an uninitialized_var. [ tglx: Addressed the same issue in futex_compat.c and massaged the changelog ] Signed-off-by: Darren Hart <dvhart@linux.intel.com> Tested-by: Matt Fleming <matt@console-pimps.org> Tested-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: John Kacur <jkacur@redhat.com> Cc: Ingo Molnar <mingo@elte.hu> LKML-Reference: <1288897200-13008-1-git-send-email-dvhart@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2010-11-10posix-cpu-timers: Rcu_read_lock/unlock protect find_task_by_vpid callSergey Senozhatsky1-6/+6
Commit 4221a9918e38b7494cee341dda7b7b4bb8c04bde "Add RCU check for find_task_by_vpid()" introduced rcu_lockdep_assert to find_task_by_pid_ns. Add rcu_read_lock/rcu_read_unlock to call find_task_by_vpid. Tetsuo Handa wrote: | Quoting from one of posts in that thead | http://kerneltrap.org/mailarchive/linux-kernel/2010/2/8/4536388 | || Usually tasklist gives enough protection, but if copy_process() fails || it calls free_pid() lockless and does call_rcu(delayed_put_pid(). || This means, without rcu lock find_pid_ns() can't scan the hash table || safely. Thomas Gleixner wrote: | We can remove the tasklist_lock while at it. rcu_read_lock is enough. Patch also replaces thread_group_leader with has_group_leader_pid in accordance to comment by Oleg Nesterov: | ... thread_group_leader() check is not relaible without | tasklist. If we race with de_thread() find_task_by_vpid() can find | the new leader before it updates its ->group_leader. | | perhaps it makes sense to change posix_cpu_timer_create() to use | has_group_leader_pid() instead, just to make this code not look racy | and avoid adding new problems. Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Stanislaw Gruszka <sgruszka@redhat.com> Reviewed-by: Oleg Nesterov <oleg@redhat.com> LKML-Reference: <20101103165256.GD30053@swordfish.minsk.epam.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2010-11-10[S390] ftrace: build without frame pointers on s390Heiko Carstens1-1/+1
s390 doesn't need FRAME_POINTERS in order to have a working function tracer. We don't need frame pointers in order to get strack traces since we always have valid backchains by using the -mkernel-backchain gcc option. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2010-11-05watchdog: Fix section mismatch and potential undefined behavior.David Daney1-1/+1
Commit d9ca07a05ce1 ("watchdog: Avoid kernel crash when disabling watchdog") introduces a section mismatch. Now that we reference no_watchdog from non-__init code it can no longer be __initdata. Signed-off-by: David Daney <ddaney@caviumnetworks.com> Cc: Stephane Eranian <eranian@google.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-11-05posix-cpu-timers: workaround to suppress the problems with mt execOleg Nesterov1-0/+8
posix-cpu-timers.c correctly assumes that the dying process does posix_cpu_timers_exit_group() and removes all !CPUCLOCK_PERTHREAD timers from signal->cpu_timers list. But, it also assumes that timer->it.cpu.task is always the group leader, and thus the dead ->task means the dead thread group. This is obviously not true after de_thread() changes the leader. After that almost every posix_cpu_timer_ method has problems. It is not simple to fix this bug correctly. First of all, I think that timer->it.cpu should use struct pid instead of task_struct. Also, the locking should be reworked completely. In particular, tasklist_lock should not be used at all. This all needs a lot of nontrivial and hard-to-test changes. Change __exit_signal() to do posix_cpu_timers_exit_group() when the old leader dies during exec. This is not the fix, just the temporary hack to hide the problem for 2.6.37 and stable. IOW, this is obviously wrong but this is what we currently have anyway: cpu timers do not work after mt exec. In theory this change adds another race. The exiting leader can detach the timers which were attached to the new leader. However, the window between de_thread() and release_task() is small, we can pretend that sys_timer_create() was called before de_thread(). Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-11-05Clean up relay_alloc_page_array() slightly by using vzalloc rather than ↵Jesper Juhl1-11/+4
vmalloc and memset We can optimize kernel/relay.c::relay_alloc_page_array() slightly by using vzalloc. The patch makes these changes: - use vzalloc instead of vmalloc+memset. - remove redundant local variable 'array'. - declare local 'pa_size' as const. Cuts down nicely on both source and object-code size. Signed-off-by: Jesper Juhl <jj@chaosbits.net> Acked-by: Pekka Enberg <penberg@kernel.org> Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-31Merge branches 'irq-core-for-linus' and 'core-locking-for-linus' of ↵Linus Torvalds1-0/+4
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: genirq: Fix up irq_node() for irq_data changes. genirq: Add single IRQ reservation helper genirq: Warn if enable_irq is called before irq is set up * 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: semaphore: Remove mutex emulation staging: Final semaphore cleanup jbd2: Convert jbd2_slab_create_sem to mutex hpfs: Convert sbi->hpfs_creation_de to mutex Fix up trivial change/delete conflicts with deleted 'dream' drivers (drivers/staging/dream/camera/{mt9d112.c,mt9p012_fox.c,mt9t013.c,s5k3e2fx.c})
2010-10-30Merge branches 'perf-fixes-for-linus' and 'x86-fixes-for-linus' of ↵Linus Torvalds2-21/+82
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: jump label: Add work around to i386 gcc asm goto bug x86, ftrace: Use safe noops, drop trap test jump_label: Fix unaligned traps on sparc. jump label: Make arch_jump_label_text_poke_early() optional jump label: Fix error with preempt disable holding mutex oprofile: Remove deprecated use of flush_scheduled_work() oprofile: Fix the hang while taking the cpu offline jump label: Fix deadlock b/w jump_label_mutex vs. text_mutex jump label: Fix module __init section race * 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: x86: Check irq_remapped instead of remapping_enabled in destroy_irq()
2010-10-30audit mmapAl Viro1-0/+16
Normal syscall audit doesn't catch 5th argument of syscall. It also doesn't catch the contents of userland structures pointed to be syscall argument, so for both old and new mmap(2) ABI it doesn't record the descriptor we are mapping. For old one it also misses flags. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-10-30audit: Use rcu for task lookup protectionThomas Gleixner1-16/+14
Protect the task lookups in audit_receive_msg() with rcu_read_lock() instead of tasklist_lock and use lock/unlock_sighand to protect against the exit race. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Eric Paris <eparis@redhat.com> Cc: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-10-30audit: Do not send uninitialized data for AUDIT_TTY_GETThomas Gleixner1-2/+4
audit_receive_msg() sends uninitialized data for AUDIT_TTY_GET when the task was not found. Send reply only when task was found. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Eric Paris <eparis@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-10-30audit: Call tty_audit_push_task() outside preempt disabledThomas Gleixner1-16/+9
While auditing all tasklist_lock read_lock sites I stumbled over the following call chain: audit_prepare_user_tty() read_lock(&tasklist_lock); tty_audit_push_task(); mutex_lock(&buf->mutex); --> buf->mutex is locked with preemption disabled. Solve this by acquiring a reference to the task struct under rcu_read_lock and call tty_audit_push_task outside of the preempt disabled region. Move all code which needs to be protected by sighand lock into tty_audit_push_task() and use lock/unlock_sighand as we do not hold tasklist_lock. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Eric Paris <eparis@redhat.com> Cc: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-10-30in untag_chunk() we need to do alloc_chunk() a bit earlierAl Viro1-2/+7
... while we are not holding spinlocks. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-10-30audit: make functions staticStephen Hemminger3-9/+6
I was doing some namespace checks and found some simple stuff in audit that could be cleaned up. Make some functions static, and put const on make_reply payload arg. Signed-off-by: Stephen Hemminger <shemminger@vyatta.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-10-30Audit: add support to match lsm labels on user audit messagesMiloslav Trmac1-0/+12
Add support for matching by security label (e.g. SELinux context) of the sender of an user-space audit record. The audit filter code already allows user space to configure such filters, but they were ignored during evaluation. This patch implements evaluation of these filters. For example, after application of this patch, PAM authentication logs caused by cron can be disabled using auditctl -a user,never -F subj_type=crond_t Signed-off-by: Miloslav Trmac <mitr@redhat.com> Acked-by: Eric Paris <eparis@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-10-29Merge branch 'for_linus' of ↵Linus Torvalds2-49/+15
git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/linux-2.6-kgdb * 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/linux-2.6-kgdb: kgdb,ppc: Individual register get/set for ppc kgdbts: prevent re-entry to kgdbts before it unregisters debug_core,x86,blackfin: Clean up hw debug disable API kdb: Fix early debugging crash regression kgdb,arm: fix register dump kdb: fix per_cpu command to remove supress mask kdb: Add kdb kernel module sample
2010-10-29debug_core,x86,blackfin: Clean up hw debug disable APIDongdong Deng1-13/+3
The kgdb_disable_hw_debug() was an architecture specific function for disabling all hardware breakpoints on a per cpu basis when entering the debug core. This patch will remove the weak function kdbg_disable_hw_debug() and change it into a call back which lives with the rest of hw breakpoint call backs in struct kgdb_arch. Signed-off-by: Dongdong Deng <dongdong.deng@windriver.com> Signed-off-by: Jason Wessel <jason.wessel@windriver.com>