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* kprobes: improve kretprobe scalability with hashed lockingSrinivasa D S2008-07-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* [IA64] kprobes: kprobe-booster for ia64Masami Hiramatsu2008-04-09
| | | | | | | | | | | | | | | | | | | | | | | | | | | Add kprobe-booster support on ia64. Kprobe-booster improves the performance of kprobes by eliminating single-step, where possible. Currently, kprobe-booster is implemented on x86 and x86-64. This is an ia64 port. On ia64, kprobe-booster executes a copied bundle directly, instead of single stepping. Bundles which have B or X unit and which may cause an exception (including break) are not executed directly. And also, to prevent hitting break exceptions on the copied bundle, only the hindmost kprobe is executed directly if several kprobes share a bundle and are placed in different slots. Note: set_brl_inst() is used for preparing an instruction buffer(it does not modify any active code), so it does not need any atomic operation. Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com> Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: bibo,mao <bibo.mao@intel.com> Cc: Rusty Lynch <rusty.lynch@intel.com> Cc: Prasanna S Panchamukhi <prasanna@in.ibm.com> Cc: Jim Keniston <jkenisto@us.ibm.com> Cc: Shaohua Li <shaohua.li@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Tony Luck <tony.luck@intel.com>
* [IA64] kprobes arch consolidation build fixHarvey Harrison2008-03-06
| | | | | | | | | ia64 named their handler kprobes_fault_handler while all other arches used kprobe_fault_handler. Change the function definition and header declaration. Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Signed-off-by: Tony Luck <tony.luck@intel.com>
* [IA64] fix ia64 kprobes compilationAdrian Bunk2008-03-04
| | | | | | | | | This patch fixes the following compile error with a recent gcc: CC kernel/kprobes.o /home/bunk/linux/kernel-2.6/git/linux-2.6/kernel/kprobes.c:1066: error: __ksymtab_jprobe_return causes a section type conflict Signed-off-by: Adrian Bunk <bunk@kernel.org> Signed-off-by: Tony Luck <tony.luck@intel.com>
* [IA64] Fix the order of atomic operations in restore_previous_kprobes on ia64Masami Hiramatsu2008-02-04
| | | | | | | | | Fix the order of atomic operations to prevent overwriting prev_kprobe[0]. To pop values from stack, we must decrement stack index right AFTER reading values. Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com> Signed-off-by: Tony Luck <tony.luck@intel.com>
* [IA64] kprobe: make kreturn probe handler stack unwind correctShaohua Li2007-12-07
| | | | | | | | | | Restore regs->ccr_iip before kreturn probe handler runs. In this way, if probe handler does unwind, unwind can correctly get the stack trace. Fixes: http://sourceware.org/bugzilla/show_bug.cgi?id=5051 Signed-off-by: Shaohua Li <shaohua.li@intel.com> Signed-off-by: Tony Luck <tony.luck@intel.com>
* [IA64] Add missing "space" to concatenated stringsJoe Perches2007-12-07
| | | | | Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Tony Luck <tony.luck@intel.com>
* kprobes: support kretprobe blacklistMasami Hiramatsu2007-10-16
| | | | | | | | | | | | | | | | | Introduce architecture dependent kretprobe blacklists to prohibit users from inserting return probes on the function in which kprobes can be inserted but kretprobes can not. This patch also removes "__kprobes" mark from "__switch_to" on x86_64 and registers "__switch_to" to the blacklist on x86-64, because that mark is to prohibit user from inserting only kretprobe. Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com> Cc: Prasanna S Panchamukhi <prasanna@in.ibm.com> Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* jprobes: make jprobes a little safer for usersMichael Ellerman2007-07-19
| | | | | | | | | | | | | | | | | | | | | | | | | I realise jprobes are a razor-blades-included type of interface, but that doesn't mean we can't try and make them safer to use. This guy I know once wrote code like this: struct jprobe jp = { .kp.symbol_name = "foo", .entry = "jprobe_foo" }; And then his kernel exploded. Oops. This patch adds an arch hook, arch_deref_entry_point() (I don't like it either) which takes the void * in a struct jprobe, and gives back the text address that it represents. We can then use that in register_jprobe() to check that the entry point we're passed is actually in the kernel text, rather than just some random value. Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Cc: Prasanna S Panchamukhi <prasanna@in.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> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [IA64] optimize pagefaults a littleChristoph Hellwig2007-05-16
| | | | | | | | | Get rid of the notifier list and call the kprobes code directly if compiled in. This mirrors the changes that recently went into powerpc, s390 and sparc64. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Tony Luck <tony.luck@intel.com>
* [IA64] spelling fixes: arch/ia64/Simon Arlott2007-05-11
| | | | | | | Spelling and apostrophe fixes in arch/ia64/. Signed-off-by: Simon Arlott <simon@fire.lp0.eu> Signed-off-by: Tony Luck <tony.luck@intel.com>
* [IA64] fix Kprobes reentrancyAnil S Keshavamurthy2007-05-11
| | | | | | | | | | | | | | | | | | In case of reentrance i.e when a probe handler calls a functions which inturn has a probe, we save a previous kprobe information and just single step the reentrant probe without calling the actual probe handler. During this reentracy period, if an interrupt occurs and if probe happens to trigger in the inturrupt path, then we were corrupting the previous kprobe( as we were overriding the previous kprobe info) info their by crashing the system. This patch fixes this issues by having a an array of previous kprobe info struct(with the array size of 2). This similar technique is not needed on i386 and x86_64 because by default interrupts are turn off in the break/int3 exception handler. Signed-off-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Tony Luck <tony.luck@intel.com>
* Kprobes: The ON/OFF knob thru debugfsAnanth N Mavinakayanahalli2007-05-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch provides a debugfs knob to turn kprobes on/off o A new file /debug/kprobes/enabled indicates if kprobes is enabled or not (default enabled) o Echoing 0 to this file will disarm all installed probes o Any new probe registration when disabled will register the probe but not arm it. A message will be printed out in such a case. o When a value 1 is echoed to the file, all probes (including ones registered in the intervening period) will be enabled o Unregistration will happen irrespective of whether probes are globally enabled or not. o Update Documentation/kprobes.txt to reflect these changes. While there also update the doc to make it current. We are also looking at providing sysrq key support to tie to the disabling feature provided by this patch. [akpm@linux-foundation.org: Use bool like a bool!] [akpm@linux-foundation.org: add printk facility levels] [cornelia.huck@de.ibm.com: Add the missing arch_trampoline_kprobe() for s390] Signed-off-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Signed-off-by: Srinivasa DS <srinivasa@in.ibm.com> Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* kprobes: kretprobes simplificationsChristoph Hellwig2007-05-08
| | | | | | | | | | | | | | | | | - consolidate duplicate code in all arch_prepare_kretprobe instances into common code - replace various odd helpers that use hlist_for_each_entry to get the first elemenet of a list with either a hlist_for_each_entry_save or an opencoded access to the first element in the caller - inline add_rp_inst into it's only remaining caller - use kretprobe_inst_table_head instead of opencoding it Signed-off-by: Christoph Hellwig <hch@lst.de> Cc: Prasanna S Panchamukhi <prasanna@in.ibm.com> Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Kprobes: print details of kretprobe on assertion failureAnanth N Mavinakayanahalli2007-05-08
| | | | | | | | | | | | | | | | | | In certain cases like when the real return address can't be found or when the number of tracked calls to a kretprobed function is less than the number of returns, we may not be able to find the correct return address after processing a kretprobe. Currently we just do a BUG_ON, but no information is provided about the actual failing kretprobe. Print out details of the kretprobe before calling BUG(). Signed-off-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Prasanna S Panchamukhi <prasanna@in.ibm.com> Cc: Jim Keniston <jkenisto@us.ibm.com> Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Cc: Maneesh Soni <maneesh@in.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* move die notifier handling to common codeChristoph Hellwig2007-05-08
| | | | | | | | | | | | | | | | | | | | | | | This patch moves the die notifier handling to common code. Previous various architectures had exactly the same code for it. Note that the new code is compiled unconditionally, this should be understood as an appel to the other architecture maintainer to implement support for it aswell (aka sprinkling a notify_die or two in the proper place) arm had a notifiy_die that did something totally different, I renamed it to arm_notify_die as part of the patch and made it static to the file it's declared and used at. avr32 used to pass slightly less information through this interface and I brought it into line with the other architectures. [akpm@linux-foundation.org: build fix] [akpm@linux-foundation.org: fix vmalloc_sync_all bustage] [bryan.wu@analog.com: fix vmalloc_sync_all in nommu] Signed-off-by: Christoph Hellwig <hch@lst.de> Cc: <linux-arch@vger.kernel.org> Cc: Russell King <rmk@arm.linux.org.uk> Signed-off-by: Bryan Wu <bryan.wu@analog.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [IA64] kprobe clears qp bits for special instructionsbibo,mao2006-12-12
| | | | | | | | | | | | On IA64 there exists some special instructions which always need to be executed regradless of qp bits, such as com.crel.unc, tbit.trel.unc etc. This patch clears qp bits when inserting kprobe trap code and disables probepoint on slot 1 for these special instructions. Signed-off-by: bibo,mao <bibo.mao@intel.com> Signed-off-by: Tony Luck <tony.luck@intel.com>
* [IA64] enable trap code on slot 1Tony Luck2006-12-12
| | | | | | | | | | | | | | Because slot 1 of one instr bundle crosses border of two consecutive 8-bytes, kprobe on slot 1 is disabled. This patch enables kprobe on slot1, it only replaces higher 8-bytes of the instruction bundle and changes the exception code to ignore the low 12 bits of the break number (which is across the border in the lower 8-bytes of the bundle). For those instructions which must execute regardless qp bits, kprobe on slot 1 is still disabled. Signed-off-by: bibo,mao <bibo.mao@intel.com> Signed-off-by: Tony Luck <tony.luck@intel.com>
* Merge branch 'release' of ↵Linus Torvalds2006-12-07
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | master.kernel.org:/pub/scm/linux/kernel/git/aegl/linux-2.6 * 'release' of master.kernel.org:/pub/scm/linux/kernel/git/aegl/linux-2.6: [IA64] replace kmalloc+memset with kzalloc [IA64] resolve name clash by renaming is_available_memory() [IA64] Need export for csum_ipv6_magic [IA64] Fix DISCONTIGMEM without VIRTUAL_MEM_MAP [PATCH] Add support for type argument in PAL_GET_PSTATE [IA64] tidy up return value of ip_fast_csum [IA64] implement csum_ipv6_magic for ia64. [IA64] More Itanium PAL spec updates [IA64] Update processor_info features [IA64] Add se bit to Processor State Parameter structure [IA64] Add dp bit to cache and bus check structs [IA64] SN: Correctly update smp_affinty mask [IA64] sparse cleanups [IA64] IA64 Kexec/kdump
| * [IA64] sparse cleanupsMatthew Wilcox2006-12-07
| | | | | | | | | | | | | | 0/NULL confusion and some missing UL on constants. Signed-off-by: Matthew Wilcox <matthew@wil.cx> Signed-off-by: Tony Luck <tony.luck@intel.com>
* | [PATCH] kprobes: enable booster on the preemptible kernelMasami Hiramatsu2006-12-07
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When we are unregistering a kprobe-booster, we can't release its instruction buffer immediately on the preemptive kernel, because some processes might be preempted on the buffer. The freeze_processes() and thaw_processes() functions can clean most of processes up from the buffer. There are still some non-frozen threads who have the PF_NOFREEZE flag. If those threads are sleeping (not preempted) at the known place outside the buffer, we can ensure safety of freeing. However, the processing of this check routine takes a long time. So, this patch introduces the garbage collection mechanism of insn_slot. It also introduces the "dirty" flag to free_insn_slot because of efficiency. The "clean" instruction slots (dirty flag is cleared) are released immediately. But the "dirty" slots which are used by boosted kprobes, are marked as garbages. collect_garbage_slots() will be invoked to release "dirty" slots if there are more than INSNS_PER_PAGE garbage slots or if there are no unused slots. Cc: "Keshavamurthy, Anil S" <anil.s.keshavamurthy@intel.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: "bibo,mao" <bibo.mao@intel.com> Cc: Prasanna S Panchamukhi <prasanna@in.ibm.com> Cc: Yumiko Sugita <yumiko.sugita.yf@hitachi.com> Cc: Satoshi Oshima <soshima@redhat.com> Cc: Hideo Aoki <haoki@redhat.com> Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] kretprobe spinlock deadlock patchbibo,mao2006-10-02
| | | | | | | | | | | | kprobe_flush_task() possibly calls kfree function during holding kretprobe_lock spinlock, if kfree function is probed by kretprobe that will incur spinlock deadlock. This patch moves kfree function out scope of kretprobe_lock. Signed-off-by: bibo, mao <bibo.mao@intel.com> Signed-off-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] kprobe whitespace cleanupbibo,mao2006-10-02
| | | | | | | | | | | Whitespace is used to indent, this patch cleans up these sentences by kernel coding style. Signed-off-by: bibo, mao <bibo.mao@intel.com> Signed-off-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: "Luck, Tony" <tony.luck@intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [IA64] kprobes: fixup the pagefault exception caused by probehandlersKeshavamurthy Anil S2006-09-26
| | | | | | | | | | If the user-specified kprobe handler causes the page fault when accessing user space address, fixup this fault since do_page_fault() should not continue as the kprobe handler are run with preemption disabled. Signed-off-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Tony Luck <tony.luck@intel.com>
* [IA64] kprobe opcode 16 bytes alignment on IA64bibo mao2006-09-26
| | | | | | | | | | | | On IA64 instruction opcode must be 16 bytes alignment, in kprobe structure there is one element to save original instruction, currently saved opcode is not statically allocated in kprobe structure, that can not assure 16 bytes alignment. This patch dynamically allocated kprobe instruction opcode to assure 16 bytes alignment. Signed-off-by: bibo mao <bibo.mao@intel.com> Acked-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Signed-off-by: Tony Luck <tony.luck@intel.com>
* [PATCH] IA64: kprobe invalidate icache of jump bufferbibo, mao2006-07-31
| | | | | | | | | | | | | | | | Kprobe inserts breakpoint instruction in probepoint and then jumps to instruction slot when breakpoint is hit, the instruction slot icache must be consistent with dcache. Here is the patch which invalidates instruction slot icache area. Without this patch, in some machines there will be fault when executing instruction slot where icache content is inconsistent with dcache. Signed-off-by: bibo,mao <bibo.mao@intel.com> Acked-by: "Luck, Tony" <tony.luck@intel.com> Acked-by: Keshavamurthy Anil S <anil.s.keshavamurthy@intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* Remove obsolete #include <linux/config.h>Jörn Engel2006-06-30
| | | | | Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de> Signed-off-by: Adrian Bunk <bunk@stusta.de>
* [PATCH] Switch Kprobes inline functions to __kprobes for ia64Prasanna S Panchamukhi2006-04-19
| | | | | | | | | | | | | | | | Andrew Morton pointed out that compiler might not inline the functions marked for inline in kprobes. There-by allowing the insertion of probes on these kprobes routines, which might cause recursion. This patch removes all such inline and adds them to kprobes section there by disallowing probes on all such routines. Some of the routines can even still be inlined, since these routines gets executed after the kprobes had done necessay setup for reentrancy. Signed-off-by: Prasanna S Panchamukhi <prasanna@in.ibm.com> Cc: "Luck, Tony" <tony.luck@intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] kprobes: fix broken fault handling for ia64Prasanna S Panchamukhi2006-03-26
| | | | | | | | | | | | | | | | | | | | Provide proper kprobes fault handling, if a user-specified pre/post handlers tries to access user address space, through copy_from_user(), get_user() etc. The user-specified fault handler gets called only if the fault occurs while executing user-specified handlers. In such a case user-specified handler is allowed to fix it first, later if the user-specifed fault handler does not fix it, we try to fix it by calling fix_exception(). The user-specified handler will not be called if the fault happens when single stepping the original instruction, instead we reset the current probe and allow the system page fault handler to fix it up. Signed-off-by: Prasanna S Panchamukhi <prasanna@in.ibm.com> Acked-by: Anil S Keshavamurthy<anil.s.keshavamurthy@intel.com> Cc: "Luck, Tony" <tony.luck@intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] kprobe handler: discard user space trapbibo,mao2006-03-26
| | | | | | | | | | | | | | Currently kprobe handler traps only happen in kernel space, so function kprobe_exceptions_notify should skip traps which happen in user space. This patch modifies this, and it is based on 2.6.16-rc4. Signed-off-by: bibo mao <bibo.mao@intel.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: "Keshavamurthy, Anil S" <anil.s.keshavamurthy@intel.com> Cc: <hiramatu@sdl.hitachi.co.jp> Signed-off-by: Prasanna S Panchamukhi <prasanna@in.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [IA64] prevent accidental modification of args in jprobe handlerZhang Yanmin2006-01-13
| | | | | | | | | | | When jprobe is hit, the function parameters of the original function should be saved before jprobe handler is executed, and restored it after jprobe handler is executed, because jprobe handler might change the register values due to tail call optimization by the gcc. Signed-off-by: Zhang Yanmin <yanmin.zhang@intel.com> Signed-off-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Signed-off-by: Tony Luck <tony.luck@intel.com>
* [PATCH] kprobes: fix race in recovery of reentrant probeKeshavamurthy Anil S2006-01-11
| | | | | | | | | | | | | | | | | There is a window where a probe gets removed right after the probe is hit on some different cpu. In this case probe handlers can't find a matching probe instance related to break address. In this case we need to read the original instruction at break address to see if that is not a break/int3 instruction and recover safely. Previous code had a bug where we were not checking for the above race in case of reentrant probes and the below patch fixes this race. Tested on IA64, Powerpc, x86_64. Signed-off-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] kprobes: arch_remove_kprobeAnil S Keshavamurthy2006-01-10
| | | | | | | | | | | | | Currently arch_remove_kprobes() is only implemented/required for x86_64 and powerpc. All other architecture like IA64, i386 and sparc64 implementes a dummy function which is being called from arch independent kprobes.c file. This patch removes the dummy functions and replaces it with #define arch_remove_kprobe(p, s) do { } while(0) Signed-off-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] kprobes: increment kprobe missed count for multiprobesKeshavamurthy Anil S2005-12-12
| | | | | | | | | | | | | | When multiple probes are registered at the same address and if due to some recursion (probe getting triggered within a probe handler), we skip calling pre_handlers and just increment nmissed field. The below patch make sure it walks the list for multiple probes case. Without the below patch we get incorrect results of nmissed count for multiple probe case. Signed-off-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [IA64] Remove getting break_num by decoding instructionKeshavamurthy Anil S2005-11-29
| | | | | | | | | | | | | | | | break.b always sets cr.iim to 0 and the current code tries to get the break_num by decoding instruction. However, their seems to be a race condition while reading the regs->cr_iip, as on other cpu the break.b at regs->cr_iip might have been replaced with the original instruction as a result of unregister_kprobe() and hence decoding instruction to obtain break_num will result in wrong value in this case. Also includes changes to kprobes.c which now has to handle break number zero. Signed-off-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Signed-off-by: Tony Luck <tony.luck@intel.com>
* [IA64] Extend notify_die() hooks for IA64Keith Owens2005-11-07
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | notify_die() added for MCA_{MONARCH,SLAVE,RENDEZVOUS}_{ENTER,PROCESS,LEAVE} and INIT_{MONARCH,SLAVE}_{ENTER,PROCESS,LEAVE}. We need multiple notification points for these events because they can take many seconds to run which has nasty effects on the behaviour of the rest of the system. DIE_SS replaced by a generic DIE_FAULT which checks the vector number, to allow interception of faults other than SS. DIE_MACHINE_{HALT,RESTART} added to allow last minute close down processing, especially when the halt/restart routines are called from error handlers. DIE_OOPS added. The check for kprobe's break numbers has been moved from traps.c to kprobes.c, allowing DIE_BREAK to be used for any additional break numbers, i.e. it is no longer kprobes specific. Hooks for kernel debuggers and kernel dumpers added, ENTER and LEAVE. Both of these disable the system for long periods which impact on watchdogs and heartbeat systems in general. More patches to come that use these events to reset watchdogs and heartbeats. unregister_die_notifier() added and both routines exported. Requested by Dean Nelson. Lock removed from {un,}register_die_notifier. notifier_chain_register() already takes a lock. Also the generic notifier chain locking is being reworked to distinguish between callbacks that can block and those that cannot, the lock in {un,}register_die_notifier would interfere with that change. http://marc.theaimsgroup.com/?l=linux-kernel&m=113018709002036&w=2 Leading white space removed from arch/ia64/kernel/kprobes.c. Typo in mca.c in original version of this patch found & fixed by Dean Nelson. Signed-off-by: Keith Owens <kaos@sgi.com> Acked-by: Dean Nelson <dcn@sgi.com> Acked-by: Anil Keshavamurthy <anil.s.keshavamurthy@intel.com> Signed-off-by: Tony Luck <tony.luck@intel.com>
* [PATCH] Kprobes: preempt_disable/enable() simplificationAnanth N Mavinakayanahalli2005-11-07
| | | | | | | | | | | Reorganize the preempt_disable/enable calls to eliminate the extra preempt depth. Changes based on Paul McKenney's review suggestions for the kprobes RCU changeset. Signed-off-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Signed-off-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Kprobes: Use RCU for (un)register synchronization - arch changesAnanth N Mavinakayanahalli2005-11-07
| | | | | | | | | | | | Changes to the arch kprobes infrastructure to take advantage of the locking changes introduced by usage of RCU for synchronization. All handlers are now run without any locks held, so they have to be re-entrant or provide their own synchronization. Signed-off-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Signed-off-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Kprobes: Track kprobe on a per_cpu basis - ia64 changesAnanth N Mavinakayanahalli2005-11-07
| | | | | | | | | | | IA64 changes to track kprobe execution on a per-cpu basis. We now track the kprobe state machine independently on each cpu using an arch specific kprobe control block. Signed-off-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Signed-off-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Kprobes: rearrange preempt_disable/enable() callsAnanth N Mavinakayanahalli2005-11-07
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The following set of patches are aimed at improving kprobes scalability. We currently serialize kprobe registration, unregistration and handler execution using a single spinlock - kprobe_lock. With these changes, kprobe handlers can run without any locks held. It also allows for simultaneous kprobe handler executions on different processors as we now track kprobe execution on a per processor basis. It is now necessary that the handlers be re-entrant since handlers can run concurrently on multiple processors. All changes have been tested on i386, ia64, ppc64 and x86_64, while sparc64 has been compile tested only. The patches can be viewed as 3 logical chunks: patch 1: Reorder preempt_(dis/en)able calls patches 2-7: Introduce per_cpu data areas to track kprobe execution patches 8-9: Use RCU to synchronize kprobe (un)registration and handler execution. Thanks to Maneesh Soni, James Keniston and Anil Keshavamurthy for their review and suggestions. Thanks again to Anil, Hien Nguyen and Kevin Stafford for testing the patches. This patch: Reorder preempt_disable/enable() calls in arch kprobes files in preparation to introduce locking changes. No functional changes introduced by this patch. Signed-off-by: Ananth N Mavinakayahanalli <ananth@in.ibm.com> Signed-off-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] kprobes: fix bug when probed on task and isr functionsKeshavamurthy Anil S2005-09-07
| | | | | | | | | | | | | | | | This patch fixes a race condition where in system used to hang or sometime crash within minutes when kprobes are inserted on ISR routine and a task routine. The fix has been stress tested on i386, ia64, pp64 and on x86_64. To reproduce the problem insert kprobes on schedule() and do_IRQ() functions and you should see hang or system crash. Signed-off-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Signed-off-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Acked-by: Prasanna S Panchamukhi <prasanna@in.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Kprobes/IA64: fix race when break hits and kprobe not foundKeshavamurthy Anil S2005-09-07
| | | | | | | | | | | | | | | | | This patch addresses a potential race condition for a case where Kprobe has been removed right after another CPU has taken a break hit. The way this is addressed here is when the CPU that has taken a break hit does not find its corresponding kprobe, then we check to see if the original instruction got replaced with other than break. If it got replaced with other than break instruction, then we continue to execute from the replaced instruction, else if we find that it is still a break, then we let the kernel handle this, as this might be the break instruction inserted by other than kprobe(may be kernel debugger). Signed-off-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Kprobes: prevent possible race conditions ia64 changesPrasanna S Panchamukhi2005-09-07
| | | | | | | | | This patch contains the ia64 architecture specific changes to prevent the possible race conditions. Signed-off-by: Prasanna S Panchamukhi <prasanna@in.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] kprobes: fix namespace problem and sparc64 buildRusty Lynch2005-07-05
| | | | | | | | | | | | The following renames arch_init, a kprobes function for performing any architecture specific initialization, to arch_init_kprobes in order to cleanup the namespace. Also, this patch adds arch_init_kprobes to sparc64 to fix the sparc64 kprobes build from the last return probe patch. Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] kprobes/ia64: refuse kprobe on ivt codeKeshavamurthy Anil S2005-06-27
| | | | | | | | | | | | Not safe to insert kprobes on IVT code. This patch checks to see if the address on which Kprobes is being inserted is in ivt code and if it is in ivt code then refuse to register kprobe. Signed-off-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Acked-by: David Mosberger <davidm@napali.hpl.hp.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] kprobes/ia64: refuse inserting kprobe on slot 1Rusty Lynch2005-06-27
| | | | | | | | | | | | Without the ability to atomically write 16 bytes, we can not update the middle slot of a bundle, slot 1, unless we stop the machine first. This patch will ensure the ability to robustly insert and remove a kprobe by refusing to insert a kprobe on slot 1 until a mechanism is in place to safely handle this case. Signed-off-by: Rusty Lynch <rusty.lynch@intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Return probe redesign: ia64 specific implementationRusty Lynch2005-06-27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The following patch implements function return probes for ia64 using the revised design. With this new design we no longer need to do some of the odd hacks previous required on the last ia64 return probe port that I sent out for comments. Note that this new implementation still does not resolve the problem noted by Keith Owens where backtrace data is lost after a return probe is hit. Changes include: * Addition of kretprobe_trampoline to act as a dummy function for instrumented functions to return to, and for the return probe infrastructure to place a kprobe on on, gaining control so that the return probe handler can be called, and so that the instruction pointer can be moved back to the original return address. * Addition of arch_init(), allowing a kprobe to be registered on kretprobe_trampoline * Addition of trampoline_probe_handler() which is used as the pre_handler for the kprobe inserted on kretprobe_implementation. This is the function that handles the details for calling the return probe handler function and returning control back at the original return address * Addition of arch_prepare_kretprobe() which is setup as the pre_handler for a kprobe registered at the beginning of the target function by kernel/kprobes.c so that a return probe instance can be setup when a caller enters the target function. (A return probe instance contains all the needed information for trampoline_probe_handler to do it's job.) * Hooks added to the exit path of a task so that we can cleanup any left-over return probe instances (i.e. if a task dies while inside a targeted function then the return probe instance was reserved at the beginning of the function but the function never returns so we need to mark the instance as unused.) Signed-off-by: Rusty Lynch <rusty.lynch@intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Kprobes/ia64: temporary disarming of reentrant probeAnil S Keshavamurthy2005-06-23
| | | | | | | | | | | | This patch includes IA64 architecture specific changes(ported form i386) to support temporary disarming on reentrancy of probes. In case of reentrancy we single step without calling user handler. Signed-of-by: Anil S Keshavamurth <anil.s.keshavamurthy@intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Kprobes/IA64: check jprobe break before handlingKeshavamurthy Anil S2005-06-23
| | | | | | | | | | | | | Once the jprobe instrumented function returns, it executes a jprobe_break which is a break instruction with __IA64_JPROBE_BREAK value. The current patch checks for this break value, before assuming that jprobe instrumented function just completed. The previous code was not checking for this value and that was a bug. Signed-off-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Kprobes IA64: safe register kprobeAnil S Keshavamurthy2005-06-23
| | | | | | | | | | | | | | | The current kprobes does not yet handle register kprobes on some of the following kind of instruction which needs to be emulated in a special way. 1) mov r1=ip 2) chk -- Speculation check instruction This patch attempts to fail register_kprobes() when user tries to insert kprobes on the above kind of instruction. Signed-off-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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