sysrq: Allow magic SysRq key functions to be disabled through Kconfig Turn the initial value of sysctl kernel.sysrq (SYSRQ_DEFAULT_ENABLE) into a Kconfig variable. Original version by Bastian Blank <waldi@debian.org>. Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Remove GENERIC_HARDIRQ config option After the last architecture switched to generic hard irqs the config options HAVE_GENERIC_HARDIRQS & GENERIC_HARDIRQS and the related code for !CONFIG_GENERIC_HARDIRQS can be removed. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
rbtree: allow tests to run as builtin No reason require rbtree test code to be a module, allow it to be builtin (streamlines my development process) Signed-off-by: Cody P Schafer <cody@linux.vnet.ibm.com> Reviewed-by: Seth Jennings <sjenning@linux.vnet.ibm.com> Cc: David Woodhouse <David.Woodhouse@intel.com> Cc: Rik van Riel <riel@redhat.com> Cc: Michel Lespinasse <walken@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Merge tag 'arc-v3.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc Pull ARC changes from Vineet Gupta: - ARC MM changes: - preparation for MMUv4 (accomodate new PTE bits, new cmds) - Rework the ASID allocation algorithm to remove asid-mm reverse map - Boilerplate code consolidation in Exception Handlers - Disable FRAME_POINTER for ARC - Unaligned Access Emulation for Big-Endian from Noam - Bunch of fixes (udelay, missing accessors) from Mischa * tag 'arc-v3.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc: ARC: fix new Section mismatches in build (post __cpuinit cleanup) Kconfig.debug: Add FRAME_POINTER anti-dependency for ARC ARC: Fix __udelay calculation ARC: remove console_verbose() from setup_arch() ARC: Add read*_relaxed to asm/io.h ARC: Handle un-aligned user space access in BE. ARC: [ASID] Track ASID allocation cycles/generations ARC: [ASID] activate_mm() == switch_mm() ARC: [ASID] get_new_mmu_context() to conditionally allocate new ASID ARC: [ASID] Refactor the TLB paranoid debug code ARC: [ASID] Remove legacy/unused debug code ARC: No need to flush the TLB in early boot ARC: MMUv4 preps/3 - Abstract out TLB Insert/Delete ARC: MMUv4 preps/2 - Reshuffle PTE bits ARC: MMUv4 preps/1 - Fold PTE K/U access flags ARC: Code cosmetics (Nothing semantical) ARC: Entry Handler tweaks: Optimize away redundant IRQ_DISABLE_SAVE ARC: Exception Handlers Code consolidation ARC: Add some .gitignore entries
Kconfig.debug: Add FRAME_POINTER anti-dependency for ARC Frame pointer on ARC doesn't serve the conventional purpose of stack unwinding due to the typical way ABI designates it's usage. Thus it's explicit usage on ARC is discouraged (gcc is free to use it, for some tricky stack frames even if -fomit-frame-pointer). Hence no point enabling it for ARC. References: http://www.spinics.net/lists/kernel/msg1593937.html Signed-off-by: Vineet Gupta <vgupta@synopsys.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: "Paul E. McKenney" <paul.mckenney@linaro.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Michel Lespinasse <walken@google.com> Cc: linux-kernel@vger.kernel.org
kobject: delayed kobject release: help find buggy drivers Implement debugging for kobject release functions. kobjects are reference counted, so the drop of the last reference to them is not predictable. However, the common case is for the last reference to be the kobject's removal from a subsystem, which results in the release function being immediately called. This can hide subtle bugs, which can occur when another thread holds a reference to the kobject at the same time that a kobject is removed. This results in the release method being delayed. In order to make these kinds of problems more visible, the following patch implements a delayed release; this has the effect that the release function will be out of order with respect to the removal of the kobject in the same manner that it would be if a reference was being held. This provides us with an easy way to allow driver writers to debug their drivers and fix otherwise hidden problems. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
kernel: delete __cpuinit usage from all core kernel files The __cpuinit type of throwaway sections might have made sense some time ago when RAM was more constrained, but now the savings do not offset the cost and complications. For example, the fix in commit 5e427ec2d0 ("x86: Fix bit corruption at CPU resume time") is a good example of the nasty type of bugs that can be created with improper use of the various __init prefixes. After a discussion on LKML[1] it was decided that cpuinit should go the way of devinit and be phased out. Once all the users are gone, we can then finally remove the macros themselves from linux/init.h. This removes all the uses of the __cpuinit macros from C files in the core kernel directories (kernel, init, lib, mm, and include) that don't really have a specific maintainer. [1] https://lkml.org/lkml/2013/5/20/589 Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus Pull MIPS updates from Ralf Baechle: "MIPS updates: - All the things that didn't make 3.10. - Removes the Windriver PPMC platform. Nobody will miss it. - Remove a workaround from kernel/irq/irqdomain.c which was there exclusivly for MIPS. Patch by Grant Likely. - More small improvments for the SEAD 3 platform - Improvments on the BMIPS / SMP support for the BCM63xx series. - Various cleanups of dead leftovers. - Platform support for the Cavium Octeon-based EdgeRouter Lite. Two large KVM patchsets didn't make it for this pull request because their respective authors are vacationing" * 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus: (124 commits) MIPS: Kconfig: Add missing MODULES dependency to VPE_LOADER MIPS: BCM63xx: CLK: Add dummy clk_{set,round}_rate() functions MIPS: SEAD3: Disable L2 cache on SEAD-3. MIPS: BCM63xx: Enable second core SMP on BCM6328 if available MIPS: BCM63xx: Add SMP support to prom.c MIPS: define write{b,w,l,q}_relaxed MIPS: Expose missing pci_io{map,unmap} declarations MIPS: Malta: Update GCMP detection. Revert "MIPS: make CAC_ADDR and UNCAC_ADDR account for PHYS_OFFSET" MIPS: APSP: Remove <asm/kspd.h> SSB: Kconfig: Amend SSB_EMBEDDED dependencies MIPS: microMIPS: Fix improper definition of ISA exception bit. MIPS: Don't try to decode microMIPS branch instructions where they cannot exist. MIPS: Declare emulate_load_store_microMIPS as a static function. MIPS: Fix typos and cleanup comment MIPS: Cleanup indentation and whitespace MIPS: BMIPS: support booting from physical CPU other than 0 MIPS: Only set cpu_has_mmips if SYS_SUPPORTS_MICROMIPS MIPS: GIC: Fix gic_set_affinity infinite loop MIPS: Don't save/restore OCTEON wide multiplier state on syscalls. ...
Merge branch 'kconfig-diet' from Dave Hansen Merge Kconfig menu diet patches from Dave Hansen: "I think the "Kernel Hacking" menu has gotten a bit out of hand. It is over 120 lines long on my system with everything enabled and options are scattered around it haphazardly. http://sr71.net/~dave/linux/kconfig-horror.png Let's try to introduce some sanity. This set takes that 120 lines down to 55 and makes it vastly easier to find some things. It's a start. This set stands on its own, but there is plenty of room for follow-up patches. The arch-specific debug options still end up getting stuck in the top-level "kernel hacking" menu. OPTIMIZE_INLINING, for instance, could obviously go in to the "compiler options" menu, but the fact that it is defined in arch/ in a separate Kconfig file keeps it on its own for the moment. The Signed-off-by's in here look funky. I changed employers while working on this set, so I have signoffs from both email addresses" * emailed patches from Dave Hansen <dave@sr71.net>: hang and lockup detection menu kconfig: consolidate printk options group locking debugging options consolidate compilation option configs consolidate runtime testing configs order memory debugging Kconfig options consolidate per-arch stack overflow debugging options
hang and lockup detection menu The hard/softlockup and hung-task entries take up 6 lines of screen real-estate when enabled. I bet folks don't mess with these _that_ often, so move them in a group down a level. Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
kconfig: consolidate printk options Same deal, take the printk-related things and hide them in a menu. This takes another 4 items out of the top-level menu. Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
group locking debugging options Original posting: http://lkml.kernel.org/r/20121214184208.D9E5804D@kernel.stglabs.ibm.com There are quite a few of these, and we want to make sure that there is one-stop-shopping for lock debugging. Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
consolidate compilation option configs Original Post: http://lkml.kernel.org/r/20121214184207.6E00DDEC@kernel.stglabs.ibm.com Again, trying to come up with some common themes of the stuff in the kernel hacking menu... There are quite a few options to tweak compilation in some way, or perform extra compile-time checks. Give them their own menu. The diff here looks a bit funny... makes it look like I'm moving debugfs even though I'm actually moving the options on either side of it. Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
consolidate runtime testing configs Original posting: http://lkml.kernel.org/r/20121214184206.FC11422F@kernel.stglabs.ibm.com These runtime tests are great, except that there are a lot of them, and they are very rarely needed. Give them their own menu so that only the folks who need them will have to go looking for them. Note that there are some other runtime tests that are not in here, like for RCU or locking. This menu should only be used for tests that do not have a more appropriate home. Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
order memory debugging Kconfig options Original posting: http://lkml.kernel.org/r/20121214184203.37E6C724@kernel.stglabs.ibm.com There are a *LOT* of memory debugging options. They are just scattered all over the "Kernel Hacking" menu. Sure, "memory debugging" is a very vague term and it's going to be hard to make absolute rules about what goes in here, but this has to be better than what we had before. This does, however, leave out the architecture-specific memory debugging options (like x86's DEBUG_SET_MODULE_RONX). There would need to be some substantial changes to move those in here. Kconfig can not easily mix arch-specific and generic options together: it really requires a file per-architecture, and I think having an arch/foo/Kconfig.debug-memory might be taking things a bit too far Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
consolidate per-arch stack overflow debugging options Original posting: http://lkml.kernel.org/r/20121214184202.F54094D9@kernel.stglabs.ibm.com Several architectures have similar stack debugging config options. They all pretty much do the same thing, some with slightly differing help text. This patch changes the architectures to instead enable a Kconfig boolean, and then use that boolean in the generic Kconfig.debug to present the actual menu option. This removes a bunch of duplication and adds consistency across arches. Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com> Reviewed-by: H. Peter Anvin <hpa@zytor.com> Reviewed-by: James Hogan <james.hogan@imgtec.com> Acked-by: Chris Metcalf <cmetcalf@tilera.com> [for tile] Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mutex: Add w/w mutex slowpath debugging Injects EDEADLK conditions at pseudo-random interval, with exponential backoff up to UINT_MAX (to ensure that every lock operation still completes in a reasonable time). This way we can test the wound slowpath even for ww mutex users where contention is never expected, and the ww deadlock avoidance algorithm is only needed for correctness against malicious userspace. An example would be protecting kernel modesetting properties, which thanks to single-threaded X isn't really expected to contend, ever. I've looked into using the CONFIG_FAULT_INJECTION infrastructure, but decided against it for two reasons: - EDEADLK handling is mandatory for ww mutex users and should never affect the outcome of a syscall. This is in contrast to -ENOMEM injection. So fine configurability isn't required. - The fault injection framework only allows to set a simple probability for failure. Now the probability that a ww mutex acquire stage with N locks will never complete (due to too many injected EDEADLK backoffs) is zero. But the expected number of ww_mutex_lock operations for the completely uncontended case would be O(exp(N)). The per-acuiqire ctx exponential backoff solution choosen here only results in O(log N) overhead due to injection and so O(log N * N) lock operations. This way we can fail with high probability (and so have good test coverage even for fancy backoff and lock acquisition paths) without running into patalogical cases. Note that EDEADLK will only ever be injected when we managed to acquire the lock. This prevents any behaviour changes for users which rely on the EALREADY semantics. Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> Signed-off-by: Maarten Lankhorst <maarten.lankhorst@canonical.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: dri-devel@lists.freedesktop.org Cc: linaro-mm-sig@lists.linaro.org Cc: rostedt@goodmis.org Cc: daniel@ffwll.ch Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20130620113117.4001.21681.stgit@patser Signed-off-by: Ingo Molnar <mingo@kernel.org>
lib/Kconfig.debug: Restrict FRAME_POINTER for MIPS FAULT_INJECTION_STACKTRACE_FILTER selects FRAME_POINTER but that symbol is not available for MIPS. Fixes the following problem on a randconfig: warning: (LOCKDEP && FAULT_INJECTION_STACKTRACE_FILTER && LATENCYTOP && KMEMCHECK) selects FRAME_POINTER which has unmet direct dependencies (DEBUG_KERNEL && (CRIS || M68K || FRV || UML || AVR32 || SUPERH || BLACKFIN || MN10300 || METAG) || ARCH_WANT_FRAME_POINTERS) Signed-off-by: Markos Chandras <markos.chandras@imgtec.com> Acked-by: Steven J. Hill <Steven.Hill@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/5441/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
notifier-error-inject: fix module names in Kconfig The Kconfig help text for MEMORY_NOTIFIER_ERROR_INJECT and OF_RECONFIG_NOTIFIER_ERROR_INJECT has mismatched module names. Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Kconfig: consolidate CONFIG_DEBUG_STRICT_USER_COPY_CHECKS The help text for this config is duplicated across the x86, parisc, and s390 Kconfig.debug files. Arnd Bergman noted that the help text was slightly misleading and should be fixed to state that enabling this option isn't a problem when using pre 4.4 gcc. To simplify the rewording, consolidate the text into lib/Kconfig.debug and modify it there to be more explicit about when you should say N to this config. Also, make the text a bit more generic by stating that this option enables compile time checks so we can cover architectures which emit warnings vs. ones which emit errors. The details of how an architecture decided to implement the checks isn't as important as the concept of compile time checking of copy_from_user() calls. While we're doing this, remove all the copy_from_user_overflow() code that's duplicated many times and place it into lib/ so that any architecture supporting this option can get the function for free. Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Ingo Molnar <mingo@kernel.org> Acked-by: H. Peter Anvin <hpa@zytor.com> Cc: Arjan van de Ven <arjan@linux.intel.com> Acked-by: Helge Deller <deller@gmx.de> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Chris Metcalf <cmetcalf@tilera.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>