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* make kprobes.c:kretprobe_table_lock() staticAdrian Bunk2008-10-161-1/+1
| | | | | | | | | 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>
* kprobes: remove redundant config checkAbhishek Sagar2008-07-251-5/+0
| | | | | | | | | | | | 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>
* kprobes: improve kretprobe scalability with hashed lockingSrinivasa D S2008-07-251-38/+89
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* kernel/kprobes.c: Made kprobe_blacklist static.Daniel Guilak2008-07-101-1/+1
| | | | | Signed-off-by: Daniel Guilak <daniel@danielguilak.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* kprobes: fix error checking of batch registrationMasami Hiramatsu2008-06-121-6/+9
| | | | | | | | | | | | | 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>
* kprobes: add (un)register_jprobes for batch registrationMasami Hiramatsu2008-04-281-9/+56
| | | | | | | | | | | | | | 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>
* kprobes: add (un)register_kretprobes for batch registrationMasami Hiramatsu2008-04-281-20/+88
| | | | | | | | | | | | | | 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>
* kprobes: add (un)register_kprobes for batch registrationMasami Hiramatsu2008-04-281-37/+87
| | | | | | | | | | | | | | | | 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>
* kprobes: prevent probing of preempt_schedule()Srinivasa Ds2008-04-281-0/+52
| | | | | | | | | | | | | | | | | | | | | | 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>
* kprobes: fix a null pointer bug in register_kretprobe()Masami Hiramatsu2008-03-041-17/+26
| | | | | | | | | | | | | | 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>
* Kprobes: indicate kretprobe support in KconfigAnanth N Mavinakayanahalli2008-03-041-6/+3
| | | | | | | | | | | | | | | | | 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>
* kprobes: kretprobe user entry-handlerAbhishek Sagar2008-02-061-1/+8
| | | | | | | | | | | | | | Provide support to add an optional user defined callback to be run at function entry of a kretprobe'd function. Also modify the kprobe smoke tests to include an entry-handler during the kretprobe sanity test. Signed-off-by: Abhishek Sagar <sagar.abhishek@gmail.com> Cc: Prasanna S Panchamukhi <prasanna@in.ibm.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Acked-by: Jim Keniston <jkenisto@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* x86: kprobes: add kprobes smoke tests that run on bootAnanth N Mavinakayanahalli2008-01-301-0/+2
| | | | | | | | | | | | | | | | | | | | | Here is a quick and naive smoke test for kprobes. This is intended to just verify if some unrelated change broke the *probes subsystem. It is self contained, architecture agnostic and isn't of any great use by itself. This needs to be built in the kernel and runs a basic set of tests to verify if kprobes, jprobes and kretprobes run fine on the kernel. In case of an error, it'll print out a message with a "BUG" prefix. This is a start; we intend to add more tests to this bucket over time. Thanks to Jim Keniston and Masami Hiramatsu for comments and suggestions. Tested on x86 (32/64) and powerpc. Signed-off-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Acked-by: Masami Hiramatsu <mhiramat@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* kprobes: support kretprobe blacklistMasami Hiramatsu2007-10-161-0/+23
| | | | | | | | | | | | | | | | | 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>
* x86: optimize page faults like all other achitectures and kill notifier cruftChristoph Hellwig2007-10-161-36/+3
| | | | | | | | | | | | | | | | | | | | | | | x86(-64) are the last architectures still using the page fault notifier cruft for the kprobes page fault hook. This patch converts them to the proper direct calls, and removes the now unused pagefault notifier bits aswell as the cruft in kprobes.c that was related to this mess. I know Andi didn't really like this, but all other architecture maintainers agreed the direct calls are much better and besides the obvious cruft removal a common way of dealing with kprobes across architectures is important aswell. [akpm@linux-foundation.org: build fix] [akpm@linux-foundation.org: fix sparc64] Signed-off-by: Christoph Hellwig <hch@lst.de> Cc: Andi Kleen <ak@suse.de> Cc: <linux-arch@vger.kernel.org> Cc: Prasanna S Panchamukhi <prasanna@in.ibm.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>
* fix compilation with gcc 4.2Peter Chubb2007-08-111-0/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | gcc-4.2 is a lot more picky about its symbol handling. EXPORT_SYMBOL no longer works on symbols that are undefined or defined with static scope. For example, with CONFIG_PROFILE off, I see: kernel/profile.c:206: error: __ksymtab_profile_event_unregister causes a section type conflict kernel/profile.c:205: error: __ksymtab_profile_event_register causes a section type conflict This patch moves the EXPORTs inside the #ifdef CONFIG_PROFILE, so we only try to export symbols that are defined. Also, in kernel/kprobes.c there's an EXPORT_SYMBOL_GPL() for jprobes_return, which if CONFIG_JPROBES is undefined is a static inline and gives the same error. And in drivers/acpi/resources/rsxface.c, there's an ACPI_EXPORT_SYMBOPL() for a static symbol. If it's static, it's not accessible from outside the compilation unit, so should bot be exported. These three changes allow building a zx1_defconfig kernel with gcc 4.2 on IA64. [akpm@linux-foundation.org: export jpobe_return properly] Signed-off-by: Peter Chubb <peterc@gelato.unsw.edu.au> Cc: Prasanna S Panchamukhi <prasanna@in.ibm.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Len Brown <lenb@kernel.org> 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 Ellerman2007-07-191-0/+9
| | | | | | | | | | | | | | | | | | | | | | | | | 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>
* Kprobes: The ON/OFF knob thru debugfsAnanth N Mavinakayanahalli2007-05-081-7/+149
| | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 Hellwig2007-05-081-43/+21
| | | | | | | | | | | | | | | | | - 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: codingstyle cleanupsChristoph Hellwig2007-05-081-25/+30
| | | | | | | | | | | Remove superflous braces and fix indentation aswell as comments. Signed-off-by: Christoph Hellwig <hch@lst.de> Cc: Prasanna S Panchamukhi <prasanna@in.ibm.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>
* kprobes: use hlist_for_each_entryChristoph Hellwig2007-05-081-6/+3
| | | | | | | | | Signed-off-by: Christoph Hellwig <hch@lst.de> Cc: Prasanna S Panchamukhi <prasanna@in.ibm.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>
* Simplify kallsyms_lookup()Alexey Dobriyan2007-05-081-2/+2
| | | | | | | | | | | | | | Several kallsyms_lookup() pass dummy arguments but only need, say, module's name. Make kallsyms_lookup() accept NULLs where possible. Also, makes picture clearer about what interfaces are needed for all symbol resolving business. Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru> Cc: Rusty Russell <rusty@rustcorp.com.au> 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>
* move die notifier handling to common codeChristoph Hellwig2007-05-081-1/+1
| | | | | | | | | | | | | | | | | | | | | | | 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>
* kprobes: fix sparse NULL warningRandy Dunlap2007-05-081-1/+2
| | | | | | | | | | Fix sparse NULL warnings: kernel/kprobes.c:915:49: warning: Using plain integer as NULL pointer Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> 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>
* [PATCH] kprobes: list all active probes in the systemSrinivasa Ds2007-02-201-2/+111
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch lists all active probes in the system by scanning through kprobe_table[]. It takes care of aggregate handlers and prints the type of the probe. Letter "k" for kprobes, "j" for jprobes, "r" for kretprobes. It also lists address of the instruction,its symbolic name(function name + offset) and the module name. One can access this file through /sys/kernel/debug/kprobes/list. Output looks like this ===================== llm40:~/a # cat /sys/kernel/debug/kprobes/list c0169ae3 r sys_read+0x0 c0169ae3 k sys_read+0x0 c01694c8 k vfs_write+0x0 c0167d20 r sys_open+0x0 f8e658a6 k reiserfs_delete_inode+0x0 reiserfs c0120f4a k do_fork+0x0 c0120f4a j do_fork+0x0 c0169b4a r sys_write+0x0 c0169b4a k sys_write+0x0 c0169622 r vfs_read+0x0 ================================= [akpm@linux-foundation.org: cleanup] [ananth@in.ibm.com: sparc build fix] Signed-off-by: Srinivasa DS <srinivasa@in.ibm.com> Cc: Prasanna S Panchamukhi <prasanna@in.ibm.com> Cc: 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>
* [PATCH] kprobes: replace magic numbers with enumMasami Hiramatsu2007-01-301-7/+13
| | | | | | | | | | | | | Replace the magic numbers with an enum, and gets rid of a warning on the specific architectures (ex. powerpc) on which the compiler considers 'char' as 'unsigned char'. Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Prasanna S Panchamukhi <prasanna@in.ibm.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [PATCH] kprobes: enable booster on the preemptible kernelMasami Hiramatsu2006-12-071-21/+96
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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,mao2006-10-021-4/+11
| | | | | | | | | | | | 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,mao2006-10-021-8/+8
| | | | | | | | | | | 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>
* [PATCH] Kprobes: Make kprobe modules more portableAnanth N Mavinakayanahalli2006-10-021-0/+26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | In an effort to make kprobe modules more portable, here is a patch that: o Introduces the "symbol_name" field to struct kprobe. The symbol->address resolution now happens in the kernel in an architecture agnostic manner. 64-bit powerpc users no longer have to specify the ".symbols" o Introduces the "offset" field to struct kprobe to allow a user to specify an offset into a symbol. o The legacy mechanism of specifying the kprobe.addr is still supported. However, if both the kprobe.addr and kprobe.symbol_name are specified, probe registration fails with an -EINVAL. o The symbol resolution code uses kallsyms_lookup_name(). So CONFIG_KPROBES now depends on CONFIG_KALLSYMS o Apparantly kprobe modules were the only legitimate out-of-tree user of the kallsyms_lookup_name() EXPORT. Now that the symbol resolution happens in-kernel, remove the EXPORT as suggested by Christoph Hellwig o Modify tcp_probe.c that uses the kprobe interface so as to make it work on multiple platforms (in its earlier form, the code wouldn't work, say, on powerpc) Signed-off-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Signed-off-by: Prasanna S Panchamukhi <prasanna@in.ibm.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] IA64: kprobe invalidate icache of jump bufferbibo, mao2006-07-311-0/+1
| | | | | | | | | | | | | | | | 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>
* [PATCH] Notify page fault call chainAnil S Keshavamurthy2006-06-261-7/+23
| | | | | | | | | | | | With this patch Kprobes now registers for page fault notifications only when their is an active probe registered. Once all the active probes are unregistered their is no need to be notified of page faults and kprobes unregisters itself from the page fault notifications. Hence we will have ZERO side effects when no probes are active. 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 registers for notify page faultAnil S Keshavamurthy2006-06-261-0/+8
| | | | | | | | Kprobes now registers for page fault notifications. Signed-off-by: Anil S Keshavamurthy <anil.s.keshavmurthy@intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Kprobe: multi kprobe posthandler for boostermao, bibo2006-06-261-8/+24
| | | | | | | | | | | | | | | | | | | | | | If there are multi kprobes on the same probepoint, there will be one extra aggr_kprobe on the head of kprobe list. The aggr_kprobe has aggr_post_handler/aggr_break_handler whether the other kprobe post_hander/break_handler is NULL or not. This patch modifies this, only when there is one or more kprobe in the list whose post_handler is not NULL, post_handler of aggr_kprobe will be set as aggr_post_handler. [soshima@redhat.com: !CONFIG_PREEMPT fix] Signed-off-by: bibo, mao <bibo.mao@intel.com> Cc: Masami Hiramatsu <hiramatu@sdl.hitachi.co.jp> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: "Keshavamurthy, Anil S" <anil.s.keshavamurthy@intel.com> Cc: Prasanna S Panchamukhi <prasanna@in.ibm.com> Cc: Jim Keniston <jkenisto@us.ibm.com> Cc: Yumiko Sugita <sugita@sdl.hitachi.co.jp> Cc: Hideo Aoki <haoki@redhat.com> Signed-off-by: Satoshi Oshima <soshima@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] kprobes: NULL out non-relevant fields in struct kretprobeAnanth N Mavinakayanahalli2006-04-201-0/+3
| | | | | | | | | | | | | | In cases where a struct kretprobe's *_handler fields are non-NULL, it is possible to cause a system crash, due to the possibility of calls ending up in zombie functions. Documentation clearly states that unused *_handlers should be set to NULL, but kprobe users sometimes fail to do so. Fix it by setting the non-relevant fields of the struct kretprobe to NULL. Signed-off-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Acked-by: Jim Keniston <jkenisto@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] kretprobe instance recycled by parent processbibo mao2006-03-261-5/+5
| | | | | | | | | | | | | | | | | When kretprobe probes the schedule() function, if the probed process exits then schedule() will never return, so some kretprobe instances will never be recycled. In this patch the parent process will recycle retprobe instances of the probed function and there will be no memory leak of kretprobe instances. Signed-off-by: bibo mao <bibo.mao@intel.com> Cc: Masami Hiramatsu <hiramatu@sdl.hitachi.co.jp> Cc: Prasanna S Panchamukhi <prasanna@in.ibm.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: 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] sem2mutex: kprobesIngo Molnar2006-03-231-7/+7
| | | | | | | | | | | | Semaphore to mutex conversion. The conversion was generated via scripts, and the result was validated automatically via a script as well. Signed-off-by: Ingo Molnar <mingo@elte.hu> Acked-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 deadlock in function-return probesAnanth N Mavinakayanahalli2006-02-031-1/+1
| | | | | | | | | | | | | | | | When two function-return probes are inserted on kfree()[1] and the second on say, sys_link()[2], and later [2] is unregistered, we have a deadlock as kfree is called with the kretprobe_lock held and the function-return probe on kfree will also try to grab the same lock. However, we can move the kfree() during unregistration to outside the spinlock as we are sure that no instances from the free list will be used after synchronized_sched() returns during the unregistration process. Thanks to Masami Hiramatsu for spotting this. 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] kernel/kprobes.c: fix a warning #ifndef ARCH_SUPPORTS_KRETPROBESAdrian Bunk2006-02-031-17/+17
| | | | | | | | | | kernel/kprobes.c:353: warning: 'pre_handler_kretprobe' defined but not used Signed-off-by: Adrian Bunk <bunk@stusta.de> Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.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>
* [PATCH] kprobes: fix unloading of self probed moduleKeshavamurthy Anil S2006-01-111-10/+32
| | | | | | | | | | | | | | | | | | When a kprobes modules is written in such a way that probes are inserted on itself, then unload of that moudle was not possible due to reference couning on the same module. The below patch makes a check and incrementes the module refcount only if it is not a self probed module. We need to allow modules to probe themself for kprobes performance measurements This patch has been tested on several x86_64, ppc64 and IA64 architectures. Signed-off-by: Anil S Keshavamurthy <anil.s.keshavamurthy> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Kprobes: conversion from kcalloc to kzallocKeshavamurthy Anil S2006-01-101-1/+1
| | | | | | | Signed-of-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 build breakageAnanth N Mavinakayanahalli2006-01-101-2/+2
| | | | | | | | | | | The following patch (against 2.6.15-rc5-mm3) fixes a kprobes build break due to changes introduced in the kprobe locking in 2.6.15-rc5-mm3. In addition, the patch reverts back the open-coding of kprobe_mutex. Signed-off-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Acked-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 Keshavamurthy2006-01-101-3/+1
| | | | | | | | | | | | | 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-changed-from-using-spinlock-to-mutex fixKeshavamurthy Anil S2006-01-101-14/+18
| | | | | | | | | Based on some feedback from Oleg Nesterov, I have made few changes to previously posted patch. 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: changed from using spinlock to mutexAnil S Keshavamurthy2006-01-101-48/+43
| | | | | | | | | | | | | | | Since Kprobes runtime exception handlers is now lock free as this code path is now using RCU to walk through the list, there is no need for the register/unregister{_kprobe} to use spin_{lock/unlock}_isr{save/restore}. The serialization during registration/unregistration is now possible using just a mutex. In the above process, this patch also fixes a minor memory leak for x86_64 and powerpc. 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: enable funcions only for required archAnil S Keshavamurthy2006-01-101-0/+2
| | | | | | | | | | | | | | | Kernel/kprobes.c defines get_insn_slot() and free_insn_slot() which are currently required _only_ for x86_64 and powerpc (which has no-exec support). FYI, get{free}_insn_slot() functions manages the memory page which is mapped as executable, required for instruction emulation. This patch moves those two functions under __ARCH_WANT_KPROBES_INSN_SLOT and defines __ARCH_WANT_KPROBES_INSN_SLOT in arch specific kprobes.h file. 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 S2005-12-121-0/+13
| | | | | | | | | | | | | | 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>
* [PATCH] kprobes: fix race in aggregate kprobe registrationKeshavamurthy Anil S2005-12-121-4/+1
| | | | | | | | | | | | | | | | When registering multiple kprobes at the same address, we leave a small window where the kprobe hlist will not contain a reference to the registered kprobe, leading to potentially, a system crash if the breakpoint is hit on another processor. Patch below now automically relpace the old kprobe with the new kprobe from the hash list. Signed-off-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Kprobes: Reference count the modules when probed on itMao, Bibo2005-12-121-2/+16
| | | | | | | | | | | | | | | When a Kprobes are inserted/removed on a modules, the modules must be ref counted so as not to allow to unload while probes are registered on that module. Without this patch, the probed module is free to unload, and when the probing module unregister the probe, the kpobes code while trying to replace the original instruction might crash. Signed-off-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Signed-off-by: Mao Bibo <bibo.mao@intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Kprobes: preempt_disable/enable() simplificationAnanth N Mavinakayanahalli2005-11-071-1/+1
| | | | | | | | | | | 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>
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