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* ARM: probes: move all probe code to dedicate directoryWang Nan2015-01-091-628/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In discussion on LKML (https://lkml.org/lkml/2014/11/28/158), Russell King suggests to move all probe related code to arch/arm/probes. This patch does the work. Due to dependency on 'arch/arm/kernel/patch.h', this patch also moves patch.h to 'arch/arm/include/asm/patch.h', and related '#include' directives are also midified to '#include <asm/patch.h>'. Following is an overview of this patch: ./arch/arm/kernel/ ./arch/arm/probes/ |-- Makefile |-- Makefile |-- probes-arm.c ==> |-- decode-arm.c |-- probes-arm.h ==> |-- decode-arm.h |-- probes-thumb.c ==> |-- decode-thumb.c |-- probes-thumb.h ==> |-- decode-thumb.h |-- probes.c ==> |-- decode.c |-- probes.h ==> |-- decode.h | |-- kprobes | | |-- Makefile |-- kprobes-arm.c ==> | |-- actions-arm.c |-- kprobes-common.c ==> | |-- actions-common.c |-- kprobes-thumb.c ==> | |-- actions-thumb.c |-- kprobes.c ==> | |-- core.c |-- kprobes.h ==> | |-- core.h |-- kprobes-test-arm.c ==> | |-- test-arm.c |-- kprobes-test.c ==> | |-- test-core.c |-- kprobes-test.h ==> | |-- test-core.h |-- kprobes-test-thumb.c ==> | `-- test-thumb.c | `-- uprobes | |-- Makefile |-- uprobes-arm.c ==> |-- actions-arm.c |-- uprobes.c ==> |-- core.c |-- uprobes.h ==> `-- core.h | `-- patch.h ==> arch/arm/include/asm/patch.h Signed-off-by: Wang Nan <wangnan0@huawei.com> Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Jon Medhurst <tixy@linaro.org>
* ARM: probes: fix instruction fetch order with <asm/opcodes.h>Ben Dooks2014-04-011-4/+5
| | | | | | | | | | | If we are running BE8, the data and instruction endianness do not match, so use <asm/opcodes.h> to correctly translate memory accesses into ARM instructions. Acked-by: Jon Medhurst <tixy@linaro.org> Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk> [taras.kondratiuk@linaro.org: fixed Thumb instruction fetch order] Signed-off-by: Taras Kondratiuk <taras.kondratiuk@linaro.org>
* ARM: Add an emulate flag to the kprobes/uprobes instruction decode functionsDavid A. Long2014-03-181-1/+1
| | | | | | | | Add an emulate flag into the instruction interpreter, primarily for uprobes support. Signed-off-by: David A. Long <dave.long@linaro.org> Acked-by: Jon Medhurst <tixy@linaro.org>
* ARM: Change the remaining shared kprobes/uprobes symbols to something genericDavid A. Long2014-03-181-4/+6
| | | | | | | | Any more ARM kprobes/uprobes symbols which have "kprobe" in the name must be changed to the more generic "probes" or other non-kprobes specific symbol. Signed-off-by: David A. Long <dave.long@linaro.org> Acked-by: Jon Medhurst <tixy@linaro.org>
* ARM: Change more ARM kprobes symbol names to something more genericDavid A. Long2014-03-181-1/+1
| | | | | | | | | | Change kprobe_emulate_none, kprobe_simulate_nop, and arm_kprobe_decode_init function names to something more appropriate for code being shared outside of the kprobes subsystem. Also, move the new arm_probes_decode_init declaration out of the kprobes.h include file and into the probes.h include file. Signed-off-by: David A. Long <dave.long@linaro.org> Acked-by: Jon Medhurst <tixy@linaro.org>
* ARM: Remove use of struct kprobe from generic probes codeDavid A. Long2014-03-181-1/+1
| | | | | | | | | | Change the generic ARM probes code to pass in the opcode and architecture-specific structure separately instead of using struct kprobe, so we do not pollute code being used only for uprobes or other non-kprobes instruction interpretation. Signed-off-by: David A. Long <dave.long@linaro.org> Acked-by: Jon Medhurst <tixy@linaro.org>
* ARM: use a function table for determining instruction interpreter actionDavid A. Long2014-03-181-2/+7
| | | | | | | | | | | Make the instruction interpreter call back to semantic action functions through a function pointer array provided by the invoker. The interpreter decodes the instructions into groups and uses the group number to index into the supplied array. kprobes and uprobes code will each supply their own array of functions. Signed-off-by: David A. Long <dave.long@linaro.org> Acked-by: Jon Medhurst <tixy@linaro.org>
* ARM: Fix missing includes in kprobes sourcesDavid A. Long2014-03-181-0/+2
| | | | | | | | Make sure includes in ARM kprobes sources are done explicitly. Do not rely on includes from other includes. Signed-off-by: David A. Long <dave.long@linaro.org> Acked-by: Jon Medhurst <tixy@linaro.org>
* ARM: 7862/1: pcpu: replace __get_cpu_var_usesChristoph Lameter2013-10-291-4/+4
| | | | | | | | | | | | | | | | | This is the ARM part of Christoph's patchset cleaning up the various uses of __get_cpu_var across the tree. The idea is to convert __get_cpu_var into either an explicit address calculation using this_cpu_ptr() or into a use of this_cpu operations that use the offset. Thereby address calculations are avoided and fewer registers are used when code is generated. [will: fixed debug ref counting checks and pcpu array accesses] Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Christoph Lameter <cl@linux.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* hlist: drop the node parameter from iteratorsSasha Levin2013-02-271-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | I'm not sure why, but the hlist for each entry iterators were conceived list_for_each_entry(pos, head, member) The hlist ones were greedy and wanted an extra parameter: hlist_for_each_entry(tpos, pos, head, member) Why did they need an extra pos parameter? I'm not quite sure. Not only they don't really need it, it also prevents the iterator from looking exactly like the list iterator, which is unfortunate. Besides the semantic patch, there was some manual work required: - Fix up the actual hlist iterators in linux/list.h - Fix up the declaration of other iterators based on the hlist ones. - A very small amount of places were using the 'node' parameter, this was modified to use 'obj->member' instead. - Coccinelle didn't handle the hlist_for_each_entry_safe iterator properly, so those had to be fixed up manually. The semantic patch which is mostly the work of Peter Senna Tschudin is here: @@ iterator name hlist_for_each_entry, hlist_for_each_entry_continue, hlist_for_each_entry_from, hlist_for_each_entry_rcu, hlist_for_each_entry_rcu_bh, hlist_for_each_entry_continue_rcu_bh, for_each_busy_worker, ax25_uid_for_each, ax25_for_each, inet_bind_bucket_for_each, sctp_for_each_hentry, sk_for_each, sk_for_each_rcu, sk_for_each_from, sk_for_each_safe, sk_for_each_bound, hlist_for_each_entry_safe, hlist_for_each_entry_continue_rcu, nr_neigh_for_each, nr_neigh_for_each_safe, nr_node_for_each, nr_node_for_each_safe, for_each_gfn_indirect_valid_sp, for_each_gfn_sp, for_each_host; type T; expression a,c,d,e; identifier b; statement S; @@ -T b; <+... when != b ( hlist_for_each_entry(a, - b, c, d) S | hlist_for_each_entry_continue(a, - b, c) S | hlist_for_each_entry_from(a, - b, c) S | hlist_for_each_entry_rcu(a, - b, c, d) S | hlist_for_each_entry_rcu_bh(a, - b, c, d) S | hlist_for_each_entry_continue_rcu_bh(a, - b, c) S | for_each_busy_worker(a, c, - b, d) S | ax25_uid_for_each(a, - b, c) S | ax25_for_each(a, - b, c) S | inet_bind_bucket_for_each(a, - b, c) S | sctp_for_each_hentry(a, - b, c) S | sk_for_each(a, - b, c) S | sk_for_each_rcu(a, - b, c) S | sk_for_each_from -(a, b) +(a) S + sk_for_each_from(a) S | sk_for_each_safe(a, - b, c, d) S | sk_for_each_bound(a, - b, c) S | hlist_for_each_entry_safe(a, - b, c, d, e) S | hlist_for_each_entry_continue_rcu(a, - b, c) S | nr_neigh_for_each(a, - b, c) S | nr_neigh_for_each_safe(a, - b, c, d) S | nr_node_for_each(a, - b, c) S | nr_node_for_each_safe(a, - b, c, d) S | - for_each_gfn_sp(a, c, d, b) S + for_each_gfn_sp(a, c, d) S | - for_each_gfn_indirect_valid_sp(a, c, d, b) S + for_each_gfn_indirect_valid_sp(a, c, d) S | for_each_host(a, - b, c) S | for_each_host_safe(a, - b, c, d) S | for_each_mesh_entry(a, - b, c, d) S ) ...+> [akpm@linux-foundation.org: drop bogus change from net/ipv4/raw.c] [akpm@linux-foundation.org: drop bogus hunk from net/ipv6/raw.c] [akpm@linux-foundation.org: checkpatch fixes] [akpm@linux-foundation.org: fix warnings] [akpm@linux-foudnation.org: redo intrusive kvm changes] Tested-by: Peter Senna Tschudin <peter.senna@gmail.com> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Sasha Levin <sasha.levin@oracle.com> Cc: Wu Fengguang <fengguang.wu@intel.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Gleb Natapov <gleb@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge tag 'for-linus' of git://github.com/rustyrussell/linuxLinus Torvalds2012-04-021-1/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull cpumask cleanups from Rusty Russell: "(Somehow forgot to send this out; it's been sitting in linux-next, and if you don't want it, it can sit there another cycle)" I'm a sucker for things that actually delete lines of code. Fix up trivial conflict in arch/arm/kernel/kprobes.c, where Rusty fixed a user of &cpu_online_map to be cpu_online_mask, but that code got deleted by commit b21d55e98ac2 ("ARM: 7332/1: extract out code patch function from kprobes"). * tag 'for-linus' of git://github.com/rustyrussell/linux: cpumask: remove old cpu_*_map. documentation: remove references to cpu_*_map. drivers/cpufreq/db8500-cpufreq: remove references to cpu_*_map. remove references to cpu_*_map in arch/
| * remove references to cpu_*_map in arch/Rusty Russell2012-03-291-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This has been obsolescent for a while; time for the final push. In adjacent context, replaced old cpus_* with cpumask_*. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Acked-by: David S. Miller <davem@davemloft.net> (arch/sparc) Acked-by: Chris Metcalf <cmetcalf@tilera.com> (arch/tile) Cc: user-mode-linux-devel@lists.sourceforge.net Cc: Russell King <linux@arm.linux.org.uk> Cc: linux-arm-kernel@lists.infradead.org Cc: Richard Kuo <rkuo@codeaurora.org> Cc: linux-hexagon@vger.kernel.org Cc: Ralf Baechle <ralf@linux-mips.org> Cc: linux-mips@linux-mips.org Cc: Kyle McMartin <kyle@mcmartin.ca> Cc: Helge Deller <deller@gmx.de> Cc: sparclinux@vger.kernel.org
* | ARM: 7332/1: extract out code patch function from kprobesRabin Vincent2012-03-241-62/+24
|/ | | | | | | | | | | | | | | | | | | | Extract out the code patching code from kprobes so that it can be used from the jump label code. Additionally, the separated code: - Uses the IS_ENABLED() macros instead of the #ifdefs for THUMB2 support - Unifies the two separate functions in kprobes, providing one function that uses stop_machine() internally, and one that can be called from stop_machine() directly - Patches the text on all CPUs only on processors requiring software broadcasting of cache operations Acked-by: Jon Medhurst <tixy@yxit.co.uk> Tested-by: Jon Medhurst <tixy@yxit.co.uk> Signed-off-by: Rabin Vincent <rabin@rab.in> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* ARM: kprobes: Extend arch_specific_insn to add pointer to emulated instructionJon Medhurst2011-07-131-0/+5
| | | | | | | | | | | | | | When we come to emulating Thumb instructions then, to interwork correctly, the code on in the instruction slot must be invoked with a function pointer which has the least significant bit set. Rather that set this by hand in every Thumb emulation function we will add a new field for this purpose to arch_specific_insn, called insn_fn. This also enables us to seamlessly share emulation functions between ARM and Thumb code. Signed-off-by: Jon Medhurst <tixy@yxit.co.uk> Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
* ARM: kprobes: Add hooks to override singlestep()Jon Medhurst2011-07-131-5/+3
| | | | | | | | | | | | | | | | | | When a probe fires we must single-step the instruction which was replaced by a breakpoint. As the steps to do this vary between ARM and Thumb instructions we need a way to customise single-stepping. This is done by adding a new hook called insn_singlestep to arch_specific_insn which is initialised by the instruction decoding functions. These single-step hooks must update PC and call the instruction handler. For Thumb instructions an additional step of updating ITSTATE is needed. We do this after calling the handler because some handlers will need to test if they are running in an IT block. Signed-off-by: Jon Medhurst <tixy@yxit.co.uk> Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
* ARM: kprobes: Use conditional breakpoints for ARM probesJon Medhurst2011-07-131-2/+8
| | | | | | | | | | | | | Now we no longer trigger probes on conditional instructions when the condition is false, we can make use of conditional instructions as breakpoints in ARM code to avoid taking unnecessary exceptions. Note, we can't rely on not getting an exception when the condition check fails, as that is Implementation Defined on newer ARM architectures. We therefore still need to perform manual condition checks as well. Signed-off-by: Jon Medhurst <tixy@yxit.co.uk> Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
* ARM: kprobes: Don't trigger probes on conditional instructions when ↵Jon Medhurst2011-07-131-1/+23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | condition is false This patch changes the behavior of kprobes on ARM so that: Kprobes on conditional instructions don't trigger when the condition is false. For conditional branches, this means that they don't trigger in the branch not taken case. Rationale: When probes are placed onto conditionally executed instructions in a Thumb IT block, they may not fire if the condition is not met. This is because we use invalid instructions for breakpoints and "it is IMPLEMENTATION DEFINED whether the instruction executes as a NOP or causes an Undefined Instruction exception". Therefore, for consistency, we will ignore all probes on any conditional instructions when the condition is false. Alternative solutions seem to be too complex to implement or inconsistent. This issue was discussed on linux.arm.kernel in the thread titled "[RFC] kprobes with thumb2 conditional code" See http://comments.gmane.org/gmane.linux.linaro.devel/2985 Signed-off-by: Jon Medhurst <tixy@yxit.co.uk> Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
* ARM: kprobes: Add Thumb breakpoint supportJon Medhurst2011-07-131-12/+110
| | | | | | | | | | | | | | | | | Extend the breakpoint insertion and catching functions to support Thumb code. As breakpoints are no longer of a fixed size, the flush_insns macro is modified to take a size argument instead of an instruction count. Note, we need both 16- and 32-bit Thumb breakpoints, because if we were to use a 16-bit breakpoint to replace a 32-bit instruction which was in an IT block, and the condition check failed, then the breakpoint may not fire (it's unpredictable behaviour) and the CPU could then try and execute the second half of the 32-bit Thumb instruction. Signed-off-by: Jon Medhurst <tixy@yxit.co.uk> Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
* ARM: kprobes: Add Thumb instruction decoding stubsJon Medhurst2011-07-131-2/+18
| | | | | | | | | Extend arch_prepare_kprobe to support probing of Thumb code. For the actual decoding of Thumb instructions, stub functions are added which currently just reject the probe. Signed-off-by: Jon Medhurst <tixy@yxit.co.uk> Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
* ARM: kprobes: Make kprobes framework work on Thumb-2 kernelsJon Medhurst2011-07-131-2/+35
| | | | | | | | Fix up kprobes framework so that it builds and correctly interworks on Thumb-2 kernels. Signed-off-by: Jon Medhurst <tixy@yxit.co.uk> Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
* ARM: kprobes: Split out internal parts of kprobes.hJon Medhurst2011-07-131-0/+2
| | | | | | | | | | | | | | Later, we will be adding a considerable amount of internal implementation definitions to kprobe header files and it would be good to have these in local header file along side the source code, rather than pollute the existing header which is include by all users of kprobes. To this end, we add arch/arm/kernel/kprobes.h and move into this the existing internal defintions from arch/arm/include/asm/kprobes.h Signed-off-by: Jon Medhurst <tixy@yxit.co.uk> Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
* ARM: kprobes: Fix probing of conditionally executed instructionsJon Medhurst2011-04-281-1/+2
| | | | | | | | | | | When a kprobe is placed onto conditionally executed ARM instructions, many of the emulation routines used to single step them produce corrupt register results. Rather than fix all of these cases we modify the framework which calls them to test the relevant condition flags and, if the test fails, skip calling the emulation code. Signed-off-by: Jon Medhurst <tixy@yxit.co.uk> Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
* Merge branch 'master' into export-slabhTejun Heo2010-04-051-1/+9
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| * ARM: 6005/1: arm: kprobes: fix register corruption with jprobesMika Westerberg2010-03-291-1/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Current implementation of jprobes allocates empty pt_regs from the stack which is then passed to kprobe_handler() and eventually to singlestep(). Now when instruction being simulated is STMFD (like in normal function prologues without CONFIG_FRAME_POINTER), stores using SP actually write over top of the fabricated pt_regs structure. This can be reproduced for example by using LKDTM module: # modprobe lkdtm # mount -t debugfs none /sys/kernel/debug # echo PANIC > /sys/kernel/debug/provoke-crash/INT_HW_IRQ_EN after this, it fails with corrupted registers (before the requested crash would occur): lkdtm: Crash point INT_HW_IRQ_EN of type PANIC hit, trigger in 9 rounds lkdtm: Crash point INT_HW_IRQ_EN of type PANIC hit, trigger in 8 rounds Internal error: Oops - undefined instruction: 0 [#1] last sysfs file: /sys/devices/platform/serial8250.0/sleep_timeout Modules linked in: lkdtm CPU: 0 Not tainted (2.6.34-rc2 #69) PC is at irq_desc+0x1638/0xeeb0 LR is at 0x25 pc : [<c050b428>] lr : [<00000025>] psr: c80a0013 sp : ce94bd60 ip : c050b3e8 fp : a0000013 r10: c0aa453c r9 : cf5d4000 r8 : ce9a1822 r7 : c050b424 r6 : 00000025 r5 : c039d8f8 r4 : c050b3e8 r3 : 00000001 r2 : cf4d0440 r1 : c039d8f8 r0 : 00000020 Flags: NZcv IRQs on FIQs on Mode SVC_32 ISA ARM Segment user Control: 10c5387d Table: 8e804019 DAC: 00000015 Process sh (pid: 496, stack limit = 0xce94a2e8) Stack: (0xce94bd60 to 0xce94c000) [...] Code: 000002cd 00000000 00000000 00000001 (dead4ead) ---[ end trace 2b46d5f2b682f370 ]--- Kernel panic - not syncing: Fatal exception in interrupt This patch allocates enough space (2 * sizeof(struct pt_regs)) from the stack to prevent such corruption. Signed-off-by: Mika Westerberg <ext-mika.1.westerberg@nokia.com> Acked-by: Nicolas Pitre <nico@marvell.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* | include cleanup: Update gfp.h and slab.h includes to prepare for breaking ↵Tejun Heo2010-03-301-0/+1
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
* ARM: 5715/1: Make kprobes unregistration SMP safeFrederic Riss2009-09-211-2/+17
| | | | | | | | | | | | | | | | | | | | ARM kprobes use an illegal instruction to trigger kprobes. In the current implementation, there's a race between the unregistration of a kprobe and the illegal instruction exception handler if they run at the same time on different cores. When reading the value of the undefined instruction, the exception handler might get the original legal instruction as just patched concurrently by arch_disarm_kprobe(). When this happen the kprobe handler won't run, and thus the exception handler will oops because it believe it just hit an undefined instruction in kernel space. The following patch synchronizes the code patching in the kprobes unregistration using stop_machine and thus avoids the above race. Signed-off-by: Frederic RISS <frederic.riss@gmail.com> Acked-by: Nicolas Pitre <nico@fluxnic.net> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* kprobes: add kprobe_insn_mutex and cleanup arch_remove_kprobe()Masami Hiramatsu2009-01-061-2/+0
| | | | | | | | | | | | | | | | | | | | | | Add kprobe_insn_mutex for protecting kprobe_insn_pages hlist, and remove kprobe_mutex from architecture dependent code. This allows us to call arch_remove_kprobe() (and free_insn_slot) while holding kprobe_mutex. Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com> Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Cc: Russell King <rmk@arm.linux.org.uk> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [ARM] 5206/1: remove kprobe_trap_handler() hackNicolas Pitre2008-09-011-1/+4
| | | | | | | | | As mentioned in commit 796969104cab0d454dbc792ad0d12a4f365a8564, and because of commit b03a5b7559563dafdbe52f8b5d8e453a914db941, the direct calling of kprobe_trap_handler() can be removed. Signed-off-by: Nicolas Pitre <nico@marvell.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* kprobes: improve kretprobe scalability with hashed lockingSrinivasa D S2008-07-251-4/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently list of kretprobe instances are stored in kretprobe object (as used_instances,free_instances) and in kretprobe hash table. We have one global kretprobe lock to serialise the access to these lists. This causes only one kretprobe handler to execute at a time. Hence affects system performance, particularly on SMP systems and when return probe is set on lot of functions (like on all systemcalls). Solution proposed here gives fine-grain locks that performs better on SMP system compared to present kretprobe implementation. Solution: 1) Instead of having one global lock to protect kretprobe instances present in kretprobe object and kretprobe hash table. We will have two locks, one lock for protecting kretprobe hash table and another lock for kretporbe object. 2) We hold lock present in kretprobe object while we modify kretprobe instance in kretprobe object and we hold per-hash-list lock while modifying kretprobe instances present in that hash list. To prevent deadlock, we never grab a per-hash-list lock while holding a kretprobe lock. 3) We can remove used_instances from struct kretprobe, as we can track used instances of kretprobe instances using kretprobe hash table. Time duration for kernel compilation ("make -j 8") on a 8-way ppc64 system with return probes set on all systemcalls looks like this. cacheline non-cacheline Un-patched kernel aligned patch aligned patch =============================================================================== real 9m46.784s 9m54.412s 10m2.450s user 40m5.715s 40m7.142s 40m4.273s sys 2m57.754s 2m58.583s 3m17.430s =========================================================== Time duration for kernel compilation ("make -j 8) on the same system, when kernel is not probed. ========================= real 9m26.389s user 40m8.775s sys 2m7.283s ========================= Signed-off-by: Srinivasa DS <srinivasa@in.ibm.com> Signed-off-by: Jim Keniston <jkenisto@us.ibm.com> Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Cc: David S. Miller <davem@davemloft.net> Cc: Masami Hiramatsu <mhiramat@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* ftrace: export kretprobe_trampoline for function tracerAbhishek Sagar2008-06-021-1/+1
| | | | | | | Follow suit from kprobe implementations on other archs and make kretprobe_trampoline non-static. Ftrace implmentation (more specifically, kernel/trace/trace.c) requires access to it (see-> http://kerneltrap.org/mailarchive/linux-kernel/2008/5/27/1955234). Signed-off-by: Abhishek Sagar <sagar.abhishek@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* kprobes/arm: fix cache flush address for instruction stubNicolas Pitre2008-04-281-1/+1
| | | | | | | | It is more useful to flush the cache with the actual buffer address rather than the address containing a pointer to the buffer. Signed-off-by: Nicolas Pitre <nico@marvell.com> Acked-by: Lennert Buytenhek <buytenh@marvell.com>
* [ARM] 4847/1: kprobes: fix compilation with CONFIG_DEBUG_FS=yNicolas Pitre2008-03-061-0/+5
| | | | | Signed-off-by: Nicolas Pitre <nico@marvell.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* ARM kprobes: special hook for the kprobes breakpoint handlerNicolas Pitre2008-01-261-7/+1
| | | | | | | | | | The kprobes code is already able to cope with reentrant probes, so its handler must be called outside of the region protected by undef_lock. If ever this lock is released when handlers are called then this commit could be reverted. Signed-off-by: Nicolas Pitre <nico@marvell.com>
* ARM kprobes: prevent some functions involved with kprobes from being probedNicolas Pitre2008-01-261-1/+1
| | | | Signed-off-by: Nicolas Pitre <nico@marvell.com>
* ARM kprobes: core codeAbhishek Sagar2008-01-261-0/+453
This is a full implementation of Kprobes including Jprobes and Kretprobes support. This ARM implementation does not follow the usual kprobes double- exception model. The traditional model is where the initial kprobes breakpoint calls kprobe_handler(), which returns from exception to execute the instruction in its original context, then immediately re-enters after a second breakpoint (or single-stepping exception) into post_kprobe_handler(), each time the probe is hit.. The ARM implementation only executes one kprobes exception per hit, so no post_kprobe_handler() phase. All side-effects from the kprobe'd instruction are resolved before returning from the initial exception. As a result, all instructions are _always_ effectively boosted regardless of the type of instruction, and even regardless of whether or not there is a post-handler for the probe. Signed-off-by: Abhishek Sagar <sagar.abhishek@gmail.com> Signed-off-by: Quentin Barnes <qbarnes@gmail.com> Signed-off-by: Nicolas Pitre <nico@marvell.com>
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