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2012-09-23rcu: Add PROVE_RCU_DELAY to provoke difficult racesPaul E. McKenney1-0/+14
There have been some recent bugs that were triggered only when preemptible RCU's __rcu_read_unlock() was preempted just after setting ->rcu_read_lock_nesting to INT_MIN, which is a low-probability event. Therefore, reproducing those bugs (to say nothing of gaining confidence in alleged fixes) was quite difficult. This commit therefore creates a new debug-only RCU kernel config option that forces a short delay in __rcu_read_unlock() to increase the probability of those sorts of bugs occurring. Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
2012-07-30powerpc: pSeries reconfig notifier error injection moduleAkinobu Mita1-0/+17
This provides the ability to inject artifical errors to pSeries reconfig notifier chain callbacks. It is controlled through debugfs interface under /sys/kernel/debug/notifier-error-inject/pSeries-reconfig If the notifier call chain should be failed with some events notified, write the error code to "actions/<notifier event>/error". Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Cc: Greg KH <greg@kroah.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <michael@ellerman.id.au> Cc: Dave Jones <davej@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-07-30memory: memory notifier error injection moduleAkinobu Mita1-0/+23
This provides the ability to inject artifical errors to memory hotplug notifier chain callbacks. It is controlled through debugfs interface under /sys/kernel/debug/notifier-error-inject/memory If the notifier call chain should be failed with some events notified, write the error code to "actions/<notifier event>/error". Example: Inject memory hotplug offline error (-12 == -ENOMEM) # cd /sys/kernel/debug/notifier-error-inject/memory # echo -12 > actions/MEM_GOING_OFFLINE/error # echo offline > /sys/devices/system/memory/memoryXXX/state bash: echo: write error: Cannot allocate memory Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Cc: Greg KH <greg@kroah.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <michael@ellerman.id.au> Cc: Dave Jones <davej@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-07-30PM: PM notifier error injection moduleAkinobu Mita1-0/+24
This provides the ability to inject artifical errors to PM notifier chain callbacks. It is controlled through debugfs interface under /sys/kernel/debug/notifier-error-inject/pm Each of the files in "error" directory represents an event which can be failed and contains the error code. If the notifier call chain should be failed with some events notified, write the error code to the files. If the notifier call chain should be failed with some events notified, write the error code to "actions/<notifier event>/error". Example: Inject PM suspend error (-12 = -ENOMEM) # cd /sys/kernel/debug/notifier-error-inject/pm # echo -12 > actions/PM_SUSPEND_PREPARE/error # echo mem > /sys/power/state bash: echo: write error: Cannot allocate memory Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Acked-by: "Rafael J. Wysocki" <rjw@sisk.pl> Cc: Pavel Machek <pavel@ucw.cz> Cc: Greg KH <greg@kroah.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <michael@ellerman.id.au> Cc: Dave Jones <davej@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-07-30cpu: rewrite cpu-notifier-error-inject moduleAkinobu Mita1-2/+14
Rewrite existing cpu-notifier-error-inject module to use debugfs based new framework. This change removes cpu_up_prepare_error and cpu_down_prepare_error module parameters which were used to specify error code to be injected. We could keep these module parameters for backward compatibility by module_param_cb but it seems overkill for this module. This provides the ability to inject artifical errors to CPU notifier chain callbacks. It is controlled through debugfs interface under /sys/kernel/debug/notifier-error-inject/cpu If the notifier call chain should be failed with some events notified, write the error code to "actions/<notifier event>/error". Example1: inject CPU offline error (-1 == -EPERM) # cd /sys/kernel/debug/notifier-error-inject/cpu # echo -1 > actions/CPU_DOWN_PREPARE/error # echo 0 > /sys/devices/system/cpu/cpu1/online bash: echo: write error: Operation not permitted Example2: inject CPU online error (-2 == -ENOENT) # cd /sys/kernel/debug/notifier-error-inject/cpu # echo -2 > actions/CPU_UP_PREPARE/error # echo 1 > /sys/devices/system/cpu/cpu1/online bash: echo: write error: No such file or directory Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Cc: Greg KH <greg@kroah.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <michael@ellerman.id.au> Cc: Dave Jones <davej@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-07-30fault-injection: notifier error injectionAkinobu Mita1-0/+11
This patchset provides kernel modules that can be used to test the error handling of notifier call chain failures by injecting artifical errors to the following notifier chain callbacks. * CPU notifier * PM notifier * memory hotplug notifier * powerpc pSeries reconfig notifier Example: Inject CPU offline error (-1 == -EPERM) # cd /sys/kernel/debug/notifier-error-inject/cpu # echo -1 > actions/CPU_DOWN_PREPARE/error # echo 0 > /sys/devices/system/cpu/cpu1/online bash: echo: write error: Operation not permitted The patchset also adds cpu and memory hotplug tests to tools/testing/selftests These tests first do simple online and offline test and then do fault injection tests if notifier error injection module is available. This patch: The notifier error injection provides the ability to inject artifical errors to specified notifier chain callbacks. It is useful to test the error handling of notifier call chain failures. This adds common basic functions to define which type of events can be fail and to initialize the debugfs interface to control what error code should be returned and which event should be failed. Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Cc: Greg KH <greg@kroah.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <michael@ellerman.id.au> Cc: Dave Jones <davej@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-07-23Merge tag 'please-pull-misc-3.6' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux Pull misc Itanium fixes from Tony Luck. * tag 'please-pull-misc-3.6' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux: debug: Do not permit CONFIG_DEBUG_STACK_USAGE=y on IA64 or PARISC [IA64] Port OOM changes to ia64_do_page_fault
2012-07-19debug: Do not permit CONFIG_DEBUG_STACK_USAGE=y on IA64 or PARISCTony Luck1-1/+1
The stack_not_used() function in <linux/sched.h> assumes that stacks grow downwards. This is not true on IA64 or PARISC, so this function would walk off in the wrong direction and into the weeds. Found on IA64 because of a compilation failure with recursive dependencies on IA64_TASKSIZE and IA64_THREAD_INFO_SIZE. Fixing the code is possible, but should be combined with other infrastructure additions to set up the "canary" at the end of the stack. Reported-by: Fengguang Wu <fengguang.wu@intel.com> (failed allmodconfig build) Signed-off-by: Tony Luck <tony.luck@intel.com>
2012-06-06Merge branch 'core/debug' into core/urgentIngo Molnar1-0/+20
Merge two debugging patchlets that were waiting for preparatory commits to hit upstream. Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-05-23Merge branches 'x86-asm-for-linus', 'x86-cleanups-for-linus', ↵Linus Torvalds1-0/+9
'x86-cpu-for-linus', 'x86-debug-for-linus' and 'x86-microcode-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull initial trivial x86 stuff from Ingo Molnar. Various random cleanups and trivial fixes. * 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86-64: Eliminate dead ia32 syscall handlers * 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/pci-calgary_64.c: Remove obsoleted simple_strtoul() usage x86: Don't continue booting if we can't load the specified initrd x86: kernel/dumpstack.c simple_strtoul cleanup x86: kernel/check.c simple_strtoul cleanup debug: Add CONFIG_READABLE_ASM x86: spinlock.h: Remove REG_PTR_MODE * 'x86-cpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/cache_info: Fix setup of l2/l3 ids * 'x86-debug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86: Avoid double stack traces with show_regs() * 'x86-microcode-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86, microcode: microcode_core.c simple_strtoul cleanup
2012-05-09printk() - restore timestamp printing at console outputKay Sievers1-6/+10
The output of the timestamps got lost with the conversion of the kmsg buffer to records; restore the old behavior. Document, that CONFIG_PRINTK_TIME now only controls the output of the timestamps in the syslog() system call and on the console, and not the recording of the timestamps. Cc: Joe Perches <joe@perches.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Sasha Levin <levinsasha928@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Reported-by: Yinghai Lu <yinghai@kernel.org> Signed-off-by: Kay Sievers <kay@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-05-07panic: Make panic_on_oops configurableKyle McMartin1-0/+20
Several distros set this by default by patching panic_on_oops. It seems to fit with the BOOTPARAM_{HARD,SOFT}_PANIC options though, so let's add a Kconfig entry and reduce some more upstream delta. Signed-off-by: Kyle McMartin <kyle@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20120411121529.GH26688@redacted.bos.redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-04-30dynamic_debug: update Documentation/*, Kconfig.debugJim Cromie1-6/+11
In dynamic-debug-howto.txt: - add section: Debug Messages at Module Initialization Time - update flags indicators in example outputs to include '=' - make flags descriptions tabular - add item on '_' flag-char - add dyndbg, boot-args examples - rewrap some paragraphs with long lines In Kconfig.debug, note that compiling with -DDEBUG enables all pr_debug()s in that code. In kernel-parameters.txt, add dyndbg and module.dyndbg items, and deprecate ddebug_query. Signed-off-by: Jim Cromie <jim.cromie@gmail.com> Acked-by: Jason Baron <jbaron@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-03-30debug: Add CONFIG_READABLE_ASMAndi Kleen1-0/+9
Add a config option to disable various gcc compiler optimizations that make assembler listings much harder to read. This is everything that reorders code significantly or creates partial functions. This is mainly to keep kernel hackers sane. Signed-off-by: Andi Kleen <ak@linux.intel.com> Link: http://lkml.kernel.org/r/1332960678-11879-2-git-send-email-andi@firstfloor.org Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2012-03-29Merge branch 'x86-urgent-for-linus' of ↵Linus Torvalds1-0/+1
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 updates from Ingo Molnar. This touches some non-x86 files due to the sanitized INLINE_SPIN_UNLOCK config usage. Fixed up trivial conflicts due to just header include changes (removing headers due to cpu_idle() merge clashing with the <asm/system.h> split). * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/apic/amd: Be more verbose about LVT offset assignments x86, tls: Off by one limit check x86/ioapic: Add io_apic_ops driver layer to allow interception x86/olpc: Add debugfs interface for EC commands x86: Merge the x86_32 and x86_64 cpu_idle() functions x86/kconfig: Remove CONFIG_TR=y from the defconfigs x86: Stop recursive fault in print_context_stack after stack overflow x86/io_apic: Move and reenable irq only when CONFIG_GENERIC_PENDING_IRQ=y x86/apic: Add separate apic_id_valid() functions for selected apic drivers locking/kconfig: Simplify INLINE_SPIN_UNLOCK usage x86/kconfig: Update defconfigs x86: Fix excessive MSR print out when show_msr is not specified
2012-03-23Merge git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/sysctlLinus Torvalds1-8/+0
Pull sysctl updates from Eric Biederman: - Rewrite of sysctl for speed and clarity. Insert/remove/Lookup in sysctl are all now O(NlogN) operations, and are no longer bottlenecks in the process of adding and removing network devices. sysctl is now focused on being a filesystem instead of system call and the code can all be found in fs/proc/proc_sysctl.c. Hopefully this means the code is now approachable. Much thanks is owed to Lucian Grinjincu for keeping at this until something was found that was usable. - The recent proc_sys_poll oops found by the fuzzer during hibernation is fixed. * git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/sysctl: (36 commits) sysctl: protect poll() in entries that may go away sysctl: Don't call sysctl_follow_link unless we are a link. sysctl: Comments to make the code clearer. sysctl: Correct error return from get_subdir sysctl: An easier to read version of find_subdir sysctl: fix memset parameters in setup_sysctl_set() sysctl: remove an unused variable sysctl: Add register_sysctl for normal sysctl users sysctl: Index sysctl directories with rbtrees. sysctl: Make the header lists per directory. sysctl: Move sysctl_check_dups into insert_header sysctl: Modify __register_sysctl_paths to take a set instead of a root and an nsproxy sysctl: Replace root_list with links between sysctl_table_sets. sysctl: Add sysctl_print_dir and use it in get_subdir sysctl: Stop requiring explicit management of sysctl directories sysctl: Add a root pointer to ctl_table_set sysctl: Rewrite proc_sys_readdir in terms of first_entry and next_entry sysctl: Rewrite proc_sys_lookup introducing find_entry and lookup_entry. sysctl: Normalize the root_table data structure. sysctl: Factor out insert_header and erase_header ...
2012-03-23nmi watchdog: do not use cpp symbol in KconfigCong Wang1-1/+1
ARCH_HAS_NMI_WATCHDOG is a macro defined by arch, but config HARDLOCKUP_DETECTOR depends on it. This is wrong, ARCH_HAS_NMI_WATCHDOG has to be a Kconfig config, and arch's need it should select it explicitly. Signed-off-by: WANG Cong <xiyou.wangcong@gmail.com> Acked-by: Don Zickus <dzickus@redhat.com> Acked-by: Mike Frysinger <vapier@gentoo.org> Cc: David Howells <dhowells@redhat.com> Cc: David Miller <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-03-23locking/kconfig: Simplify INLINE_SPIN_UNLOCK usageRaghavendra K T1-0/+1
Get rid of INLINE_SPIN_UNLOCK entirely replacing it with UNINLINE_SPIN_UNLOCK instead of the reverse meaning. Whoever wants to change the default spinlock inlining behavior and uninline the spinlocks for some weird reason, such as spinlock debugging, paravirt etc. can now all just select UNINLINE_SPIN_UNLOCK Original discussion at: https://lkml.org/lkml/2012/3/21/357 Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Chris Zankel <chris@zankel.net> Cc: linux-mips@linux-mips.org Link: http://lkml.kernel.org/r/20120322095502.30866.75756.sendpatchset@codeblue [ tidied up the changelog a bit ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-03-20Merge branch 'perf-core-for-linus' of ↵Linus Torvalds1-7/+11
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf events changes for v3.4 from Ingo Molnar: - New "hardware based branch profiling" feature both on the kernel and the tooling side, on CPUs that support it. (modern x86 Intel CPUs with the 'LBR' hardware feature currently.) This new feature is basically a sophisticated 'magnifying glass' for branch execution - something that is pretty difficult to extract from regular, function histogram centric profiles. The simplest mode is activated via 'perf record -b', and the result looks like this in perf report: $ perf record -b any_call,u -e cycles:u branchy $ perf report -b --sort=symbol 52.34% [.] main [.] f1 24.04% [.] f1 [.] f3 23.60% [.] f1 [.] f2 0.01% [k] _IO_new_file_xsputn [k] _IO_file_overflow 0.01% [k] _IO_vfprintf_internal [k] _IO_new_file_xsputn 0.01% [k] _IO_vfprintf_internal [k] strchrnul 0.01% [k] __printf [k] _IO_vfprintf_internal 0.01% [k] main [k] __printf This output shows from/to branch columns and shows the highest percentage (from,to) jump combinations - i.e. the most likely taken branches in the system. "branches" can also include function calls and any other synchronous and asynchronous transitions of the instruction pointer that are not 'next instruction' - such as system calls, traps, interrupts, etc. This feature comes with (hopefully intuitive) flat ascii and TUI support in perf report. - Various 'perf annotate' visual improvements for us assembly junkies. It will now recognize function calls in the TUI and by hitting enter you can follow the call (recursively) and back, amongst other improvements. - Multiple threads/processes recording support in perf record, perf stat, perf top - which is activated via a comma-list of PIDs: perf top -p 21483,21485 perf stat -p 21483,21485 -ddd perf record -p 21483,21485 - Support for per UID views, via the --uid paramter to perf top, perf report, etc. For example 'perf top --uid mingo' will only show the tasks that I am running, excluding other users, root, etc. - Jump label restructurings and improvements - this includes the factoring out of the (hopefully much clearer) include/linux/static_key.h generic facility: struct static_key key = STATIC_KEY_INIT_FALSE; ... if (static_key_false(&key)) do unlikely code else do likely code ... static_key_slow_inc(); ... static_key_slow_inc(); ... The static_key_false() branch will be generated into the code with as little impact to the likely code path as possible. the static_key_slow_*() APIs flip the branch via live kernel code patching. This facility can now be used more widely within the kernel to micro-optimize hot branches whose likelihood matches the static-key usage and fast/slow cost patterns. - SW function tracer improvements: perf support and filtering support. - Various hardenings of the perf.data ABI, to make older perf.data's smoother on newer tool versions, to make new features integrate more smoothly, to support cross-endian recording/analyzing workflows better, etc. - Restructuring of the kprobes code, the splitting out of 'optprobes', and a corner case bugfix. - Allow the tracing of kernel console output (printk). - Improvements/fixes to user-space RDPMC support, allowing user-space self-profiling code to extract PMU counts without performing any system calls, while playing nice with the kernel side. - 'perf bench' improvements - ... and lots of internal restructurings, cleanups and fixes that made these features possible. And, as usual this list is incomplete as there were also lots of other improvements * 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (120 commits) perf report: Fix annotate double quit issue in branch view mode perf report: Remove duplicate annotate choice in branch view mode perf/x86: Prettify pmu config literals perf report: Enable TUI in branch view mode perf report: Auto-detect branch stack sampling mode perf record: Add HEADER_BRANCH_STACK tag perf record: Provide default branch stack sampling mode option perf tools: Make perf able to read files from older ABIs perf tools: Fix ABI compatibility bug in print_event_desc() perf tools: Enable reading of perf.data files from different ABI rev perf: Add ABI reference sizes perf report: Add support for taken branch sampling perf record: Add support for sampling taken branch perf tools: Add code to support PERF_SAMPLE_BRANCH_STACK x86/kprobes: Split out optprobe related code to kprobes-opt.c x86/kprobes: Fix a bug which can modify kernel code permanently x86/kprobes: Fix instruction recovery on optimized path perf: Add callback to flush branch_stack on context switch perf: Disable PERF_SAMPLE_BRANCH_* when not supported perf/x86: Add LBR software filter support for Intel CPUs ...
2012-02-21rcu: Print scheduling-clock information on RCU CPU stall-warning messagesPaul E. McKenney1-0/+14
There have been situations where RCU CPU stall warnings were caused by issues in scheduling-clock timer initialization. To make it easier to track these down, this commit causes the RCU CPU stall-warning messages to print out the number of scheduling-clock interrupts taken in the current grace period for each stalled CPU. Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2012-02-21rcu: Move RCU_TRACE to lib/Kconfig.debugPaul E. McKenney1-0/+10
The RCU_TRACE kernel parameter has always been intended for debugging, not for production use. Formalize this by moving RCU_TRACE from init/Kconfig to lib/Kconfig.debug. Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2012-02-11watchdog: Update Kconfig entriesFernando Luis Vázquez Cao1-7/+11
The soft and hard lockup thresholds have changed so the corresponding Kconfig entries need to be updated accordingly. Add a reference to watchdog_thresh while at it. Signed-off-by: Fernando Luis Vazquez Cao <fernando@oss.ntt.co.jp> Signed-off-by: Don Zickus <dzickus@redhat.com> Link: http://lkml.kernel.org/r/1328827342-6253-2-git-send-email-dzickus@redhat.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2012-01-24sysctl: Improve the sysctl sanity checksEric W. Biederman1-8/+0
- Stop validating subdirectories now that we only register leaf tables - Cleanup and improve the duplicate filename check. * Run the duplicate filename check under the sysctl_lock to guarantee we never add duplicate names. * Reduce the duplicate filename check to nearly O(M*N) where M is the number of entries in tthe table we are registering and N is the number of entries in the directory before we got there. - Move the duplicate filename check into it's own function and call it directtly from __register_sysctl_table - Kill the config option as the sanity checks are now cheap enough the config option is unnecessary. The original reason for the config option was because we had a huge table used to verify the proc filename to binary sysctl mapping. That table has now evolved into the binary_sysctl translation layer and is no longer part of the sysctl_check code. - Tighten up the permission checks. Guarnateeing that files only have read or write permissions. - Removed redudant check for parents having a procname as now everything has a procname. - Generalize the backtrace logic so that we print a backtrace from any failure of __register_sysctl_table that was not caused by a memmory allocation failure. The backtrace allows us to track down who erroneously registered a sysctl table. Bechmark before (CONFIG_SYSCTL_CHECK=y): make-dummies 0 999 -> 12s rmmod dummy -> 0.08s Bechmark before (CONFIG_SYSCTL_CHECK=n): make-dummies 0 999 -> 0.7s rmmod dummy -> 0.06s make-dummies 0 99999 -> 1m13s rmmod dummy -> 0.38s Benchmark after: make-dummies 0 999 -> 0.65s rmmod dummy -> 0.055s make-dummies 0 9999 -> 1m10s rmmod dummy -> 0.39s The sysctl sanity checks now impose no measurable cost. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2011-12-02kmemleak: Add support for memory hotplugLaura Abbott1-1/+1
Ensure that memory hotplug can co-exist with kmemleak by taking the hotplug lock before scanning the memory banks. Signed-off-by: Laura Abbott <lauraa@codeaurora.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2011-10-31lib/Kconfig.debug: fix help message for DEFAULT_HUNG_TASK_TIMEOUTJiaju Zhang1-2/+3
Added missing _secs in the help message of config DEFAULT_HUNG_TASK_TIMEOUT. Signed-off-by: Jiaju Zhang <jjzhang@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-10-28Merge branch 'for-linus' of ↵Linus Torvalds1-0/+11
git://git.kernel.org/pub/scm/linux/kernel/git/cjb/mmc * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/cjb/mmc: (83 commits) mmc: fix compile error when CONFIG_BLOCK is not enabled mmc: core: Cleanup eMMC4.5 conditionals mmc: omap_hsmmc: if multiblock reads are broken, disable them mmc: core: add workaround for controllers with broken multiblock reads mmc: core: Prevent too long response times for suspend mmc: recognise SDIO cards with SDIO_CCCR_REV 3.00 mmc: sd: Handle SD3.0 cards not supporting UHS-I bus speed mode mmc: core: support HPI send command mmc: core: Add cache control for eMMC4.5 device mmc: core: Modify the timeout value for writing power class mmc: core: new discard feature support at eMMC v4.5 mmc: core: mmc sanitize feature support for v4.5 mmc: dw_mmc: modify DATA register offset mmc: sdhci-pci: add flag for devices that can support runtime PM mmc: omap_hsmmc: ensure pbias configuration is always done mmc: core: Add Power Off Notify Feature eMMC 4.5 mmc: sdhci-s3c: fix potential NULL dereference mmc: replace printk with appropriate display macro mmc: core: Add default timeout value for CMD6 mmc: sdhci-pci: add runtime pm support ...
2011-10-26mmc: core: add random fault injectionPer Forlin1-0/+11
This adds support to inject data errors after a completed host transfer. The mmc core will return error even though the host transfer is successful. This simple fault injection proved to be very useful to test the non-blocking error handling in the mmc_blk_issue_rw_rq(). Random faults can also test how the host driver handles pre_req() and post_req() in case of errors. Signed-off-by: Per Forlin <per.forlin@linaro.org> Acked-by: Akinobu Mita <akinobu.mita@gmail.com> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Chris Ball <cjb@laptop.org>
2011-10-25Merge branch 'for-linus' of ↵Linus Torvalds1-20/+20
git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (59 commits) MAINTAINERS: linux-m32r is moderated for non-subscribers linux@lists.openrisc.net is moderated for non-subscribers Drop default from "DM365 codec select" choice parisc: Kconfig: cleanup Kernel page size default Kconfig: remove redundant CONFIG_ prefix on two symbols cris: remove arch/cris/arch-v32/lib/nand_init.S microblaze: add missing CONFIG_ prefixes h8300: drop puzzling Kconfig dependencies MAINTAINERS: microblaze-uclinux@itee.uq.edu.au is moderated for non-subscribers tty: drop superfluous dependency in Kconfig ARM: mxc: fix Kconfig typo 'i.MX51' Fix file references in Kconfig files aic7xxx: fix Kconfig references to READMEs Fix file references in drivers/ide/ thinkpad_acpi: Fix printk typo 'bluestooth' bcmring: drop commented out line in Kconfig btmrvl_sdio: fix typo 'btmrvl_sdio_sd6888' doc: raw1394: Trivial typo fix CIFS: Don't free volume_info->UNC until we are entirely done with it. treewide: Correct spelling of successfully in comments ...
2011-10-01ARM: always use ARM_UNWIND for thumb2 kernelsArnd Bergmann1-2/+2
Thumb2 kernels cannot be built with frame pointers, but can use the ARM_UNWIND feature for unwinding instead. This makes sure that all features that rely on unwinding includeing CONFIG_LATENCYTOP and FAULT_INJECTION_STACKTRACE_FILTER do not enable frame pointers when the unwinder is already selected, and we always build with the unwinder when we want a thumb2 kernel, to make sure we do not get the frame pointers instead. A different option would be to redefine the CONFIG_FRAME_POINTERS option on ARM to mean builing with either frame pointers or the unwinder, and then select which one to use based on the CPU architecture or another user option. That would still allow building thumb2 kernels without the unwinder but would also be more confusing. Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2011-09-15Kconfig: Copyedit: DEBUG_SECTION_MISMATCHMichael Witten1-19/+19
Signed-off-by: Michael Witten <mfwitten@gmail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2011-08-23lib: Kconfig.debug: Typo remove extra "it"Justin P. Mattock1-1/+1
The patch below removes an extra "it" in the comment. Signed-off-by: Justin P. Mattock <justinmattock@gmail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2011-07-22Merge branch 'sched-core-for-linus' of ↵Linus Torvalds1-3/+6
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (24 commits) sched: Cleanup duplicate local variable in [enqueue|dequeue]_task_fair sched: Replace use of entity_key() sched: Separate group-scheduling code more clearly sched: Reorder root_domain to remove 64 bit alignment padding sched: Do not attempt to destroy uninitialized rt_bandwidth sched: Remove unused function cpu_cfs_rq() sched: Fix (harmless) typo 'CONFG_FAIR_GROUP_SCHED' sched, cgroup: Optimize load_balance_fair() sched: Don't update shares twice on on_rq parent sched: update correct entity's runtime in check_preempt_wakeup() xtensa: Use generic config PREEMPT definition h8300: Use generic config PREEMPT definition m32r: Use generic PREEMPT config sched: Skip autogroup when looking for all rt sched groups sched: Simplify mutex_spin_on_owner() sched: Remove rcu_read_lock() from wake_affine() sched: Generalize sleep inside spinlock detection sched: Make sleeping inside spinlock detection working in !CONFIG_PREEMPT sched: Isolate preempt counting in its own config option sched: Remove pointless in_atomic() definition check ...
2011-07-05lockup detector: Fix reference to the non-existent CONFIG_DETECT_SOFTLOCKUP ↵Anton Blanchard1-2/+2
option Replace CONFIG_DETECT_SOFTLOCKUP with CONFIG_LOCKUP_DETECTOR. Signed-off-by: Anton Blanchard <anton@samba.org> Acked-by: WANG Cong <xiyou.wangcong@gmail.com> Cc: fweisbec@gmail.com Cc: a.p.zijlstra@chello.nl Link: http://lkml.kernel.org/r/20110705133240.25e81a7a@kryten Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-01Merge branch 'sched/core-v2' of ↵Ingo Molnar1-3/+6
git://git.kernel.org/pub/scm/linux/kernel/git/frederic/random-tracing into sched/core
2011-06-23sched: Generalize sleep inside spinlock detectionFrederic Weisbecker1-3/+5
The sleeping inside spinlock detection is actually used for more general sleeping inside atomic sections debugging: preemption disabled, rcu read side critical sections, interrupts, interrupt disabled, etc... Change the name of the config and its help section to reflect its more general role. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Acked-by: Randy Dunlap <randy.dunlap@oracle.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Ingo Molnar <mingo@elte.hu>
2011-06-10sched: Make sleeping inside spinlock detection working in !CONFIG_PREEMPTFrederic Weisbecker1-0/+1
Select CONFIG_PREEMPT_COUNT when we enable the sleeping inside spinlock detection, so that the preempt offset gets correctly incremented/decremented from preempt_disable()/preempt_enable(). This makes the preempt count eventually working in !CONFIG_PREEMPT when that debug option is set and thus fixes the detection of explicit preemption disabled sections under such config. Code that sleeps in explicitly preempt disabled section can be finally spotted in non-preemptible kernels. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
2011-06-01tile: enable CONFIG_BUGVERBOSEChris Metcalf1-1/+1
Trivial config change to enable backtraces on panic. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2011-05-25lib: consolidate DEBUG_STACK_USAGE optionStephen Boyd1-0/+9
Most arches define CONFIG_DEBUG_STACK_USAGE exactly the same way. Move it to lib/Kconfig.debug so each arch doesn't have to define it. This obviously makes the option generic, but that's fine because the config is already used in generic code. It's not obvious to me that sysrq-P actually does anything caution by keeping the most inclusive wording. Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> Cc: Chris Metcalf <cmetcalf@tilera.com> Acked-by: David S. Miller <davem@davemloft.net> Acked-by: Richard Weinberger <richard@nod.at> Acked-by: Mike Frysinger <vapier@gentoo.org> Cc: Russell King <rmk@arm.linux.org.uk> Cc: Hirokazu Takata <takata@linux-m32r.org> Acked-by: Ralf Baechle <ralf@linux-mips.org> Cc: Paul Mackerras <paulus@samba.org> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Chen Liqin <liqin.chen@sunplusct.com> Cc: Lennox Wu <lennox.wu@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-05-25lib: consolidate DEBUG_PER_CPU_MAPSStephen Boyd1-0/+11
DEBUG_PER_CPU_MAPS is used in lib/cpumask.c as well as in inlcude/linux/cpumask.h and thus it has outgrown its use within x86 and powerpc alone. Any arch with SMP support may want to get some more debugging, so make this option generic. Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> Cc: <linux-arch@vger.kernel.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-05-23Merge branch 'for-linus' of ↵Linus Torvalds1-1/+2
git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (39 commits) b43: fix comment typo reqest -> request Haavard Skinnemoen has left Atmel cris: typo in mach-fs Makefile Kconfig: fix copy/paste-ism for dell-wmi-aio driver doc: timers-howto: fix a typo ("unsgined") perf: Only include annotate.h once in tools/perf/util/ui/browsers/annotate.c md, raid5: Fix spelling error in comment ('Ofcourse' --> 'Of course'). treewide: fix a few typos in comments regulator: change debug statement be consistent with the style of the rest Revert "arm: mach-u300/gpio: Fix mem_region resource size miscalculations" audit: acquire creds selectively to reduce atomic op overhead rtlwifi: don't touch with treewide double semicolon removal treewide: cleanup continuations and remove logging message whitespace ath9k_hw: don't touch with treewide double semicolon removal include/linux/leds-regulator.h: fix syntax in example code tty: fix typo in descripton of tty_termios_encode_baud_rate xtensa: remove obsolete BKL kernel option from defconfig m68k: fix comment typo 'occcured' arch:Kconfig.locks Remove unused config option. treewide: remove extra semicolons ...
2011-05-19Merge branch 'core-rcu-for-linus' of ↵Linus Torvalds1-29/+3
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (78 commits) Revert "rcu: Decrease memory-barrier usage based on semi-formal proof" net,rcu: convert call_rcu(prl_entry_destroy_rcu) to kfree batman,rcu: convert call_rcu(softif_neigh_free_rcu) to kfree_rcu batman,rcu: convert call_rcu(neigh_node_free_rcu) to kfree() batman,rcu: convert call_rcu(gw_node_free_rcu) to kfree_rcu net,rcu: convert call_rcu(kfree_tid_tx) to kfree_rcu() net,rcu: convert call_rcu(xt_osf_finger_free_rcu) to kfree_rcu() net/mac80211,rcu: convert call_rcu(work_free_rcu) to kfree_rcu() net,rcu: convert call_rcu(wq_free_rcu) to kfree_rcu() net,rcu: convert call_rcu(phonet_device_rcu_free) to kfree_rcu() perf,rcu: convert call_rcu(swevent_hlist_release_rcu) to kfree_rcu() perf,rcu: convert call_rcu(free_ctx) to kfree_rcu() net,rcu: convert call_rcu(__nf_ct_ext_free_rcu) to kfree_rcu() net,rcu: convert call_rcu(net_generic_release) to kfree_rcu() net,rcu: convert call_rcu(netlbl_unlhsh_free_addr6) to kfree_rcu() net,rcu: convert call_rcu(netlbl_unlhsh_free_addr4) to kfree_rcu() security,rcu: convert call_rcu(sel_netif_free) to kfree_rcu() net,rcu: convert call_rcu(xps_dev_maps_release) to kfree_rcu() net,rcu: convert call_rcu(xps_map_release) to kfree_rcu() net,rcu: convert call_rcu(rps_map_release) to kfree_rcu() ...
2011-05-19Merge branch 'core-locking-for-linus' of ↵Linus Torvalds1-0/+15
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: seqlock: Don't smp_rmb in seqlock reader spin loop watchdog, hung_task_timeout: Add Kconfig configurable default lockdep: Remove cmpxchg to update nr_chain_hlocks lockdep: Print a nicer description for simple irq lock inversions lockdep: Replace "Bad BFS generated tree" message with something less cryptic lockdep: Print a nicer description for irq inversion bugs lockdep: Print a nicer description for simple deadlocks lockdep: Print a nicer description for normal deadlocks lockdep: Print a nicer description for irq lock inversions
2011-05-19Merge branch 'for-linus' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/cmarinas/linux-2.6-cm * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/cmarinas/linux-2.6-cm: kmemleak: Initialise kmemleak after debug_objects_mem_init() kmemleak: Select DEBUG_FS unconditionally in DEBUG_KMEMLEAK kmemleak: Do not return a pointer to an object that kmemleak did not get
2011-05-19kmemleak: Select DEBUG_FS unconditionally in DEBUG_KMEMLEAKCatalin Marinas1-1/+1
In the past DEBUG_FS used to depend on SYSFS and DEBUG_KMEMLEAK selected it conditionally. This is no longer the case, so always select DEBUG_FS via DEBUG_KMEMLEAK. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2011-05-19MIPS: Enable kmemleak for MIPSMaxin John1-1/+1
Signed-off-by: Maxin B. John <maxin.john@gmail.com> To: Catalin Marinas <catalin.marinas@arm.com> Cc: Daniel Baluta <dbaluta@ixiacom.com> Cc: naveen yadav <yad.naveen@gmail.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org Patchwork: https://patchwork.linux-mips.org/patch/2244/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2011-05-05rcu: Enable DEBUG_OBJECTS_RCU_HEAD from !PREEMPTMathieu Desnoyers1-1/+1
The prohibition of DEBUG_OBJECTS_RCU_HEAD from !PREEMPT was due to the fixup actions. So just produce a warning from !PREEMPT. Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
2011-05-05rcu: Remove conditional compilation for RCU CPU stall warningsPaul E. McKenney1-28/+2
The RCU CPU stall warnings can now be controlled using the rcu_cpu_stall_suppress boot-time parameter or via the same parameter from sysfs. There is therefore no longer any reason to have kernel config parameters for this feature. This commit therefore removes the RCU_CPU_STALL_DETECTOR and RCU_CPU_STALL_DETECTOR_RUNNABLE kernel config parameters. The RCU_CPU_STALL_TIMEOUT parameter remains to allow the timeout to be tuned and the RCU_CPU_STALL_VERBOSE parameter remains to allow task-stall information to be suppressed if desired. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
2011-04-28watchdog, hung_task_timeout: Add Kconfig configurable defaultJeff Mahoney1-0/+15
This patch allows the default value for sysctl_hung_task_timeout_secs to be set at build time. The feature carries virtually no overhead, so it makes sense to keep it enabled. On heavily loaded systems, though, it can end up triggering stack traces when there is no bug other than the system being underprovisioned. We use this patch to keep the hung task facility available but disabled at boot-time. The default of 120 seconds is preserved. As a note, commit e162b39a may have accidentally reverted commit fb822db4, which raised the default from 120 seconds to 480 seconds. Signed-off-by: Jeff Mahoney <jeffm@suse.com> Acked-by: Mandeep Singh Baines <msb@google.com> Link: http://lkml.kernel.org/r/4DB8600C.8080000@suse.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-04-26Merge branch 'master' into for-nextJiri Kosina1-9/+33
Fast-forwarded to current state of Linus' tree as there are patches to be applied for files that didn't exist on the old branch.
2011-04-10add printk.time=1 boot-time hint to Kconfig.debug help textJim Cromie1-1/+2
Cite Documentation/kernel-parameters.txt for an alternative to building with PRINTK_TIME compiled in. Signed-off-by: Jim Cromie <jim.cromie@gmail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>