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2010-05-08kprobes: Move enable/disable_kprobe() out from debugfs codeMasami Hiramatsu
Move enable/disable_kprobe() API out from debugfs related code, because these interfaces are not related to debugfs interface. This fixes a compiler warning. Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com> Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Acked-by: Tony Luck <tony.luck@intel.com> Cc: systemtap <systemtap@sources.redhat.com> Cc: DLE <dle-develop@lists.sourceforge.net> LKML-Reference: <20100427223312.2322.60512.stgit@localhost6.localdomain6> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-03-11kprobes: Calculate the index correctly when freeing the out-of-line ↵Masami Hiramatsu
execution slot From : Ananth N Mavinakayanahalli <ananth@in.ibm.com> When freeing the instruction slot, the arithmetic to calculate the index of the slot in the page needs to account for the total size of the instruction on the various architectures. Calculate the index correctly when freeing the out-of-line execution slot. Reported-by: Sachin Sant <sachinp@in.ibm.com> Reported-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com> LKML-Reference: <4B9667AB.9050507@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-02-25kprobes: Jump optimization sysctl interfaceMasami Hiramatsu
Add /proc/sys/debug/kprobes-optimization sysctl which enables and disables kprobes jump optimization on the fly for debugging. Changes in v7: - Remove ctl_name = CTL_UNNUMBERED for upstream compatibility. Changes in v6: - Update comments and coding style. Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com> Cc: systemtap <systemtap@sources.redhat.com> Cc: DLE <dle-develop@lists.sourceforge.net> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Jim Keniston <jkenisto@us.ibm.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Anders Kaseorg <andersk@ksplice.com> Cc: Tim Abbott <tabbott@ksplice.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Jason Baron <jbaron@redhat.com> Cc: Mathieu Desnoyers <compudj@krystal.dyndns.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> LKML-Reference: <20100225133415.6725.8274.stgit@localhost6.localdomain6> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-02-25kprobes: Introduce kprobes jump optimizationMasami Hiramatsu
Introduce kprobes jump optimization arch-independent parts. Kprobes uses breakpoint instruction for interrupting execution flow, on some architectures, it can be replaced by a jump instruction and interruption emulation code. This gains kprobs' performance drastically. To enable this feature, set CONFIG_OPTPROBES=y (default y if the arch supports OPTPROBE). Changes in v9: - Fix a bug to optimize probe when enabling. - Check nearby probes can be optimize/unoptimize when disarming/arming kprobes, instead of registering/unregistering. This will help kprobe-tracer because most of probes on it are usually disabled. Changes in v6: - Cleanup coding style for readability. - Add comments around get/put_online_cpus(). Changes in v5: - Use get_online_cpus()/put_online_cpus() for avoiding text_mutex deadlock. Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com> Cc: systemtap <systemtap@sources.redhat.com> Cc: DLE <dle-develop@lists.sourceforge.net> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Jim Keniston <jkenisto@us.ibm.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Anders Kaseorg <andersk@ksplice.com> Cc: Tim Abbott <tabbott@ksplice.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Jason Baron <jbaron@redhat.com> Cc: Mathieu Desnoyers <compudj@krystal.dyndns.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> LKML-Reference: <20100225133407.6725.81992.stgit@localhost6.localdomain6> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-02-25kprobes: Introduce generic insn_slot frameworkMasami Hiramatsu
Make insn_slot framework support various size slots. Current insn_slot just supports one-size instruction buffer slot. However, kprobes jump optimization needs larger size buffers. Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com> Cc: systemtap <systemtap@sources.redhat.com> Cc: DLE <dle-develop@lists.sourceforge.net> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Jim Keniston <jkenisto@us.ibm.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Anders Kaseorg <andersk@ksplice.com> Cc: Tim Abbott <tabbott@ksplice.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Jason Baron <jbaron@redhat.com> Cc: Mathieu Desnoyers <compudj@krystal.dyndns.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> LKML-Reference: <20100225133358.6725.82430.stgit@localhost6.localdomain6> Signed-off-by: Ingo Molnar <mingo@elte.hu> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Jim Keniston <jkenisto@us.ibm.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Anders Kaseorg <andersk@ksplice.com> Cc: Tim Abbott <tabbott@ksplice.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Jason Baron <jbaron@redhat.com> Cc: Mathieu Desnoyers <compudj@krystal.dyndns.org>
2010-02-05kprobes: Add mcount to the kprobes blacklistMasami Hiramatsu
Since mcount function can be called from everywhere, it should be blacklisted. Moreover, the "mcount" symbol is a special symbol name. So, it is better to put it in the generic blacklist. Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com> Cc: systemtap <systemtap@sources.redhat.com> Cc: DLE <dle-develop@lists.sourceforge.net> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Steven Rostedt <rostedt@goodmis.org> LKML-Reference: <20100205062433.3745.36726.stgit@dhcp-100-2-132.bos.redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-02-04kprobes: Check probe address is reservedMasami Hiramatsu
Check whether the address of new probe is already reserved by ftrace or alternatives (on x86) when registering new probe. If reserved, it returns an error and not register the probe. Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com> Cc: systemtap <systemtap@sources.redhat.com> Cc: DLE <dle-develop@lists.sourceforge.net> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: przemyslaw@pawelczyk.it Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Jim Keniston <jkenisto@us.ibm.com> Cc: Mathieu Desnoyers <compudj@krystal.dyndns.org> Cc: Jason Baron <jbaron@redhat.com> LKML-Reference: <20100202214918.4694.94179.stgit@dhcp-100-2-132.bos.redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-02-04kprobes: Disable booster when CONFIG_PREEMPT=yMasami Hiramatsu
Disable kprobe booster when CONFIG_PREEMPT=y at this time, because it can't ensure that all kernel threads preempted on kprobe's boosted slot run out from the slot even using freeze_processes(). The booster on preemptive kernel will be resumed if synchronize_tasks() or something like that is introduced. Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com> Cc: systemtap <systemtap@sources.redhat.com> Cc: DLE <dle-develop@lists.sourceforge.net> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Jim Keniston <jkenisto@us.ibm.com> Cc: Mathieu Desnoyers <compudj@krystal.dyndns.org> Cc: Steven Rostedt <rostedt@goodmis.org> LKML-Reference: <20100202214904.4694.24330.stgit@dhcp-100-2-132.bos.redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-28kprobes: Fix distinct type warningHeiko Carstens
Every time I see this: kernel/kprobes.c: In function 'register_kretprobe': kernel/kprobes.c:1038: warning: comparison of distinct pointer types lacks a cast I'm wondering if something changed in common code and we need to do something for s390. Apparently that's not the case. Let's get rid of this annoying warning. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Masami Hiramatsu <mhiramat@redhat.com> LKML-Reference: <20091221120224.GA4471@osiris.boeblingen.de.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-05Merge branch 'perf-core-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (470 commits) x86: Fix comments of register/stack access functions perf tools: Replace %m with %a in sscanf hw-breakpoints: Keep track of user disabled breakpoints tracing/syscalls: Make syscall events print callbacks static tracing: Add DEFINE_EVENT(), DEFINE_SINGLE_EVENT() support to docbook perf: Don't free perf_mmap_data until work has been done perf_event: Fix compile error perf tools: Fix _GNU_SOURCE macro related strndup() build error trace_syscalls: Remove unused syscall_name_to_nr() trace_syscalls: Simplify syscall profile trace_syscalls: Remove duplicate init_enter_##sname() trace_syscalls: Add syscall_nr field to struct syscall_metadata trace_syscalls: Remove enter_id exit_id trace_syscalls: Set event_enter_##sname->data to its metadata trace_syscalls: Remove unused event_syscall_enter and event_syscall_exit perf_event: Initialize data.period in perf_swevent_hrtimer() perf probe: Simplify event naming perf probe: Add --list option for listing current probe events perf probe: Add argv_split() from lib/argv_split.c perf probe: Move probe event utility functions to probe-event.c ...
2009-11-02kprobes: Sanitize struct kretprobe_instance allocationsAnanth N Mavinakayanahalli
For as long as kretprobes have existed, we've allocated NR_CPUS instances of kretprobe_instance structures. With the default value of CONFIG_NR_CPUS increasing on certain architectures, we are potentially wasting kernel memory. See http://sourceware.org/bugzilla/show_bug.cgi?id=10839#c3 for more details. Use a saner num_possible_cpus() instead of NR_CPUS for allocation. Signed-off-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Acked-by: Masami Hiramatsu <mhiramat@redhat.com> Cc: Jim Keniston <jkenisto@us.ibm.com> Cc: fweisbec@gmail.com LKML-Reference: <20091030135310.GA22230@in.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-10-17Merge commit 'v2.6.32-rc5' into perf/probesIngo Molnar
Conflicts: kernel/trace/trace_event_profile.c Merge reason: update to -rc5 and resolve conflict. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-10-01const: constify remaining file_operationsAlexey Dobriyan
[akpm@linux-foundation.org: fix KVM] Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Acked-by: Mike Frysinger <vapier@gentoo.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-23Merge commit 'linus/master' into tracing/kprobesFrederic Weisbecker
Conflicts: kernel/trace/Makefile kernel/trace/trace.h kernel/trace/trace_event_types.h kernel/trace/trace_export.c Merge reason: Sync with latest significant tracing core changes.
2009-09-23seq_file: constify seq_operationsJames Morris
Make all seq_operations structs const, to help mitigate against revectoring user-triggerable function pointers. This is derived from the grsecurity patch, although generated from scratch because it's simpler than extracting the changes from there. Signed-off-by: James Morris <jmorris@namei.org> Acked-by: Serge Hallyn <serue@us.ibm.com> Acked-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-17kprobes: Prevent re-registration of the same kprobeAnanth N Mavinakayanahalli
Prevent re-registration of the same kprobe. This situation, though unlikely, needs to be flagged since it can lead to a system crash if it's not handled. The core change itself is small, but the helper routine needed to be moved around a bit; hence the diffstat. Signed-off-by: Ananth N Mavinakayanahalli<ananth@in.ibm.com> Acked-by: Masami Hiramatsu <mhiramat@redhat.com> Cc: Jim Keniston <jkenisto@us.ibm.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Frank Ch. Eigler <fche@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Jason Baron <jbaron@redhat.com> Cc: K.Prasad <prasad@linux.vnet.ibm.com> Cc: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Tom Zanussi <tzanussi@gmail.com> LKML-Reference: <20090915051307.GB26458@in.ibm.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2009-09-11kprobes/x86-32: Move irq-exit functions to kprobes sectionMasami Hiramatsu
Move irq-exit functions to .kprobes.text section to protect against kprobes recursion. When I ran kprobe stress test on x86-32, I found below symbols cause unrecoverable recursive probing: ret_from_exception ret_from_intr check_userspace restore_all restore_all_notrace restore_nocheck irq_return And also, I found some interrupt/exception entry points that cause similar problems. This patch moves those symbols (including their container functions) to .kprobes.text section to prevent any kprobes probing. Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Jim Keniston <jkenisto@us.ibm.com> Cc: Ingo Molnar <mingo@elte.hu> LKML-Reference: <20090908164755.24050.81182.stgit@dhcp-100-2-132.bos.redhat.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2009-08-30kprobes: Prohibit to probe native_get_debugregMasami Hiramatsu
Since do_debug() calls get_debugreg(), native_get_debugreg() will be called from singlestepping. This can cause an int3 infinite loop. We can't put it in the .text.kprobes section because it is inlined, then we blacklist its name. Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com> Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Ingo Molnar <mingo@elte.hu> LKML-Reference: <20090827172332.8246.34194.stgit@localhost.localdomain> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2009-08-27tracing/kprobes: Dump the culprit kprobe in case of kprobe recursionFrederic Weisbecker
Kprobes can enter into a probing recursion, ie: a kprobe that does an endless loop because one of its core mechanism function used during probing is also probed itself. This patch helps pinpointing the kprobe that raised such recursion by dumping it and raising a BUG instead of a warning (we also disarm the kprobe to try avoiding recursion in BUG itself). Having a BUG instead of a warning stops the stacktrace in the right place and doesn't pollute the logs with hundreds of traces that eventually end up in a stack overflow. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Masami Hiramatsu <mhiramat@redhat.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
2009-08-11Merge branch 'linus' into tracing/coreIngo Molnar
Conflicts: kernel/trace/trace_events_filter.c We use the tracing/core version. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-07-30kprobes: Use kernel_text_address() for checking probe addressMasami Hiramatsu
Use kernel_text_address() for checking probe address instead of __kernel_text_address(), because __kernel_text_address() returns true for init functions even after relaseing those functions. That will hit a BUG() in text_poke(). Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Jim Keniston <jkenisto@us.ibm.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-07-01kprobes: Clean up insn_pages by using list instead of hlistMasami Hiramatsu
Use struct list instead of struct hlist for managing insn_pages, because insn_pages doesn't use hash table. Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com> Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Jim Keniston <jkenisto@us.ibm.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> LKML-Reference: <20090630210814.17851.64651.stgit@localhost.localdomain> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-07-01kprobes: No need to unlock kprobe_insn_mutexMasami Hiramatsu
Remove needless kprobe_insn_mutex unlocking during safety check in garbage collection, because if someone releases a dirty slot during safety check (which ensures other cpus doesn't execute all dirty slots), the safety check must be fail. So, we need to hold the mutex while checking safety. Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Jim Keniston <jkenisto@us.ibm.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> LKML-Reference: <20090630210809.17851.28781.stgit@localhost.localdomain> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-05-08kprobes: fix to use text_mutex around arm/disarm kprobeMasami Hiramatsu
Fix kprobes to lock text_mutex around some arch_arm/disarm_kprobe() which are newly added by commit de5bd88d5a5cce3cacea904d3503e5ebdb3852a2. Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com> Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Cc: Jim Keniston <jkenisto@us.ibm.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-07kprobes: support per-kprobe disablingMasami Hiramatsu
Add disable_kprobe() and enable_kprobe() to disable/enable kprobes temporarily. disable_kprobe() asynchronously disables probe handlers of specified kprobe. So, after calling it, some handlers can be called at a while. enable_kprobe() enables specified kprobe. aggr_pre_handler and aggr_post_handler check disabled probes. On the other hand aggr_break_handler and aggr_fault_handler don't check it because these handlers will be called while executing pre or post handlers and usually those help error handling. 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: David S. Miller <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-07kprobes: rename kprobe_enabled to kprobes_all_disarmedMasami Hiramatsu
Rename kprobe_enabled to kprobes_all_disarmed and invert logic due to avoiding naming confusion from per-probe disabling. 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: David S. Miller <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-07kprobes: move EXPORT_SYMBOL_GPL just after function definitionsMasami Hiramatsu
Clean up positions of EXPORT_SYMBOL_GPL in kernel/kprobes.c according to checkpatch.pl. 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: David S. Miller <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-07kprobes: cleanup aggr_kprobe related codeMasami Hiramatsu
Currently, kprobes can disable all probes at once, but can't disable it individually (not unregister, just disable an kprobe, because unregistering needs to wait for scheduler synchronization). These patches introduce APIs for on-the-fly per-probe disabling and re-enabling by dis-arming/re-arming its breakpoint instruction. This patch: Change old_p to ap in add_new_kprobe() for readability, copy flags member in add_aggr_kprobe(), and simplify the code flow of register_aggr_kprobe(). 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: David S. Miller <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-03-18kprobes: Fix locking imbalance in kretprobesAnanth N Mavinakayanahalli
Fix locking imbalance in kretprobes: ===================================== [ BUG: bad unlock balance detected! ] ------------------------------------- kthreadd/2 is trying to release lock (&rp->lock) at: [<c06b3080>] pre_handler_kretprobe+0xea/0xf4 but there are no more locks to release! other info that might help us debug this: 1 lock held by kthreadd/2: #0: (rcu_read_lock){..--}, at: [<c06b2b24>] __atomic_notifier_call_chain+0x0/0x5a stack backtrace: Pid: 2, comm: kthreadd Not tainted 2.6.29-rc8 #1 Call Trace: [<c06ae498>] ? printk+0xf/0x17 [<c06b3080>] ? pre_handler_kretprobe+0xea/0xf4 [<c044ce6c>] print_unlock_inbalance_bug+0xc3/0xce [<c0444d4b>] ? clocksource_read+0x7/0xa [<c04450a4>] ? getnstimeofday+0x5f/0xf6 [<c044a9ca>] ? register_lock_class+0x17/0x293 [<c044b72c>] ? mark_lock+0x1e/0x30b [<c0448956>] ? tick_dev_program_event+0x4a/0xbc [<c0498100>] ? __slab_alloc+0xa5/0x415 [<c06b2fbe>] ? pre_handler_kretprobe+0x28/0xf4 [<c06b3080>] ? pre_handler_kretprobe+0xea/0xf4 [<c044cf1b>] lock_release_non_nested+0xa4/0x1a5 [<c06b3080>] ? pre_handler_kretprobe+0xea/0xf4 [<c044d15d>] lock_release+0x141/0x166 [<c06b07dd>] _spin_unlock_irqrestore+0x19/0x50 [<c06b3080>] pre_handler_kretprobe+0xea/0xf4 [<c06b20b5>] kprobe_exceptions_notify+0x1c9/0x43e [<c06b2b02>] notifier_call_chain+0x26/0x48 [<c06b2b5b>] __atomic_notifier_call_chain+0x37/0x5a [<c06b2b24>] ? __atomic_notifier_call_chain+0x0/0x5a [<c06b2b8a>] atomic_notifier_call_chain+0xc/0xe [<c0442d0d>] notify_die+0x2d/0x2f [<c06b0f9c>] do_int3+0x1f/0x71 [<c06b0e84>] int3+0x2c/0x34 [<c042d476>] ? do_fork+0x1/0x288 [<c040221b>] ? kernel_thread+0x71/0x79 [<c043ed1b>] ? kthread+0x0/0x60 [<c043ed1b>] ? kthread+0x0/0x60 [<c04040b8>] ? kernel_thread_helper+0x0/0x10 [<c043ec7f>] kthreadd+0xac/0x148 [<c043ebd3>] ? kthreadd+0x0/0x148 [<c04040bf>] kernel_thread_helper+0x7/0x10 Signed-off-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Tested-by: Bharata B Rao <bharata@linux.vnet.ibm.com> Cc: Masami Hiramatsu <mhiramat@redhat.com> Cc: Jim Keniston <jkenisto@us.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: <stable@kernel.org> [2.6.29.x, 2.6.28.x, 2.6.27.x] LKML-Reference: <20090318113621.GB4129@in.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-06tracing, Text Edit Lock - kprobes architecture independent supportMathieu Desnoyers
Use the mutual exclusion provided by the text edit lock in the kprobes code. It allows coherent manipulation of the kernel code by other subsystems. Changelog: Move the kernel_text_lock/unlock out of the for loops. Use text_mutex directly instead of a function. Remove whitespace modifications. (note : kprobes_mutex is always taken outside of text_mutex) Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Acked-by: Masami Hiramatsu <mhiramat@redhat.com> LKML-Reference: <49B14306.2080202@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-16kprobes: check CONFIG_FREEZER instead of CONFIG_PMMasami Hiramatsu
Check CONFIG_FREEZER instead of CONFIG_PM because kprobe booster depends on freeze_processes() and thaw_processes() when CONFIG_PREEMPT=y. This fixes a linkage error which occurs when CONFIG_PREEMPT=y, CONFIG_PM=y and CONFIG_FREEZER=n. Reported-by: Cheng Renquan <crquan@gmail.com> Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Len Brown <len.brown@intel.com>
2009-01-06kprobes: support probing module __init functionMasami Hiramatsu
Allow kprobes to probe module __init routines. When __init functions are freed, kprobes which probe those functions are set to "Gone" flag. These "Gone" probes are disarmed from the code and never be enabled. 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> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-06kprobes: remove called_from argumentMasami Hiramatsu
Remove called_from argument from kprobes which had been used for preventing self-refering of kernel module. However, since we don't keep module's refcount after registering kprobe any more, there is no reason to check that. This patch also simplifies registering/unregistering functions because we don't need to use __builtin_return_address(0) which was passed to called_from. [ananth@in.ibm.com: build fix] 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> Signed-off-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-06kprobes: support probing module __exit functionMasami Hiramatsu
Allows kprobes to probe __exit routine. This adds flags member to struct kprobe. When module is freed(kprobes hooks module_notifier to get this event), kprobes which probe the functions in that module are set to "Gone" flag to the flags member. These "Gone" probes are never be enabled. Users can check the GONE flag through debugfs. This also removes mod_refcounted, because we couldn't free a module if kprobe incremented the refcount of that module. [akpm@linux-foundation.org: document some locking] [mhiramat@redhat.com: bugfix: pass aggr_kprobe to arch_remove_kprobe] [mhiramat@redhat.com: bugfix: release old_p's insn_slot before error return] 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> Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-06kprobes: add __kprobes to kprobe internal functionsMasami Hiramatsu
Add __kprobes to kprobes internal functions for protecting from probing by kprobes itself. 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> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-06kprobes: add kprobe_insn_mutex and cleanup arch_remove_kprobe()Masami Hiramatsu
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>
2009-01-06kprobes: bugfix: try_module_get even if calling_mod is NULLMasami Hiramatsu
When someone called register_*probe() from kernel-core code(not from module) and that probes a kernel module, users can remove the probed module because kprobe doesn't increment reference counter of the module. (on the other hand, if the kernel-module calls register_*probe, kprobe increments refcount of the probed module.) Currently, we have no register_*probe() calling from kernel-core(except smoke-test, but the smoke-test doesn't probe module), so there is no real bugs. But the logic is wrong(or not fair) and it can causes a problem when someone might want to probe module from kernel. After this patch is applied, even if someone put register_*probe() call in the kernel-core code, it increments the reference counter of the probed module, and it prevents user to remove the module until stopping probing it. Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com> Cc: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-11-12kernel/kprobes.c: don't pad kretprobe_table_locks[] on uniprocessor buildsAndrew Morton
We only need the cacheline padding on SMP kernels. Saves 6k: text data bss dec hex filename 5713 388 8840 14941 3a5d kernel/kprobes.o 5713 388 2632 8733 221d kernel/kprobes.o Acked-by: Masami Hiramatsu <mhiramat@redhat.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-11-12kprobes: disable preempt for module_text_address() and kernel_text_address()Masami Hiramatsu
__register_kprobe() can be preempted after checking probing address but before module_text_address() or try_module_get(), and in this interval the module can be unloaded. In that case, try_module_get(probed_mod) will access to invalid address, or kprobe will probe invalid address. This patch uses preempt_disable() to protect it and uses __module_text_address() and __kernel_text_address(). Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-16make kprobes.c:kretprobe_table_lock() staticAdrian Bunk
Make the needlessly global kretprobe_table_lock() static. Signed-off-by: Adrian Bunk <bunk@kernel.org> Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-25kprobes: remove redundant config checkAbhishek Sagar
I noticed that there's a CONFIG_KPROBES check inside kernel/kprobes.c, which is redundant. Signed-off-by: Abhishek Sagar <sagar.abhishek@gmail.com> Acked-by: Masami Hiramatsu <mhiramat@redhat.com> Cc: 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>
2008-07-25kprobes: improve kretprobe scalability with hashed lockingSrinivasa D S
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>
2008-07-10kernel/kprobes.c: Made kprobe_blacklist static.Daniel Guilak
Signed-off-by: Daniel Guilak <daniel@danielguilak.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-06-12kprobes: fix error checking of batch registrationMasami Hiramatsu
Fix error checking routine to catch an error which occurs in first __register_*probe(). Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Jim Keniston <jkenisto@us.ibm.com> Cc: David Miller <davem@davemloft.net> 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>
2008-04-28kprobes: add (un)register_jprobes for batch registrationMasami Hiramatsu
Introduce unregister_/register_jprobes() for jprobe batch registration. Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Jim Keniston <jkenisto@us.ibm.com> Cc: Prasanna S Panchamukhi <prasanna@in.ibm.com> Cc: Shaohua Li <shaohua.li@intel.com> Cc: David Miller <davem@davemloft.net> Cc: "Frank Ch. Eigler" <fche@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28kprobes: add (un)register_kretprobes for batch registrationMasami Hiramatsu
Introduce unregister_/register_kretprobes() for kretprobe batch registration. Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Jim Keniston <jkenisto@us.ibm.com> Cc: Prasanna S Panchamukhi <prasanna@in.ibm.com> Cc: Shaohua Li <shaohua.li@intel.com> Cc: David Miller <davem@davemloft.net> Cc: "Frank Ch. Eigler" <fche@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28kprobes: add (un)register_kprobes for batch registrationMasami Hiramatsu
Introduce unregister_/register_kprobes() for kprobe batch registration. This can reduce waiting time for synchronized_sched() when a lot of probes have to be unregistered at once. Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Jim Keniston <jkenisto@us.ibm.com> Cc: Prasanna S Panchamukhi <prasanna@in.ibm.com> Cc: Shaohua Li <shaohua.li@intel.com> Cc: David Miller <davem@davemloft.net> Cc: "Frank Ch. Eigler" <fche@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28kprobes: prevent probing of preempt_schedule()Srinivasa Ds
Prohibit users from probing preempt_schedule(). One way of prohibiting the user from probing functions is by marking such functions with __kprobes. But this method doesn't work for those functions, which are already marked to different section like preempt_schedule() (belongs to __sched section). So we use blacklist approach to refuse user from probing these functions. In blacklist approach we populate the blacklisted function's starting address and its size in kprobe_blacklist structure. Then we verify the user specified address against start and end of the blacklisted function. So any attempt to register probe on blacklisted functions will be rejected. [akpm@linux-foundation.org: build fix] [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Srinivasa DS <srinivasa@in.ibm.com> Signed-off-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Signed-off-by: Jim Keniston <jkenisto@us.ibm.com> Cc: Dave Hansen <haveblue@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-03-04kprobes: fix a null pointer bug in register_kretprobe()Masami Hiramatsu
Fix a bug in regiseter_kretprobe() which does not check rp->kp.symbol_name == NULL before calling kprobe_lookup_name. For maintainability, this introduces kprobe_addr helper function which resolves addr field. It is used by register_kprobe and register_kretprobe. Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Jim Keniston <jkenisto@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-03-04Kprobes: indicate kretprobe support in KconfigAnanth N Mavinakayanahalli
Add CONFIG_HAVE_KRETPROBES to the arch/<arch>/Kconfig file for relevant architectures with kprobes support. This facilitates easy handling of in-kernel modules (like samples/kprobes/kretprobe_example.c) that depend on kretprobes being present in the kernel. Thanks to Sam Ravnborg for helping make the patch more lean. Per Mathieu's suggestion, added CONFIG_KRETPROBES and fixed up dependencies. Signed-off-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Acked-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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