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path: root/arch/x86/kernel/kprobes.c
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2010-09-22jump label: Add jump_label_text_reserved() to reserve jump pointsJason Baron
Add a jump_label_text_reserved(void *start, void *end), so that other pieces of code that want to modify kernel text, can first verify that jump label has not reserved the instruction. Acked-by: Masami Hiramatsu <mhiramat@redhat.com> Signed-off-by: Jason Baron <jbaron@redhat.com> LKML-Reference: <06236663a3a7b1c1f13576bb9eccb6d9c17b7bfe.1284733808.git.jbaron@redhat.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-09-15kprobes: Remove __dummy_bufNamhyung Kim
Remove __dummy_buf which is needed for kallsyms_lookup only. use kallsysm_lookup_size_offset instead. Signed-off-by: Namhyung Kim <namhyung@gmail.com> Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> LKML-Reference: <1284512670-2369-5-git-send-email-namhyung@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-09-15kprobes: Make functions staticNamhyung Kim
Make following (internal) functions static to make sparse happier :-) * get_optimized_kprobe: only called from static functions * kretprobe_table_unlock: _lock function is static * kprobes_optinsn_template_holder: never called but holding asm code Signed-off-by: Namhyung Kim <namhyung@gmail.com> Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> LKML-Reference: <1284512670-2369-4-git-send-email-namhyung@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-08-19kprobes/x86: Fix the return address of multiple kretprobesKUMANO Syuhei
Fix the return address of subsequent kretprobes when multiple kretprobes are set on the same function. For example: # cd /sys/kernel/debug/tracing # echo "r:event1 sys_symlink" > kprobe_events # echo "r:event2 sys_symlink" >> kprobe_events # echo 1 > events/kprobes/enable # ln -s /tmp/foo /tmp/bar (without this patch) # cat trace ln-897 [000] 20404.133727: event1: (kretprobe_trampoline+0x0/0x4c <- sys_symlink) ln-897 [000] 20404.133747: event2: (system_call_fastpath+0x16/0x1b <- sys_symlink) (with this patch) # cat trace ln-740 [000] 13799.491076: event1: (system_call_fastpath+0x16/0x1b <- sys_symlink) ln-740 [000] 13799.491096: event2: (system_call_fastpath+0x16/0x1b <- sys_symlink) Signed-off-by: KUMANO Syuhei <kumano.prog@gmail.com> Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org> LKML-Reference: <1281853084.3254.11.camel@camp10-laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-07-21Merge branch 'linus' into perf/coreIngo Molnar
Merge reason: Pick up the latest perf fixes. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-07-18x86: kprobes: fix swapped segment registers in kretprobeRoland McGrath
In commit f007ea26, the order of the %es and %ds segment registers got accidentally swapped, so synthesized 'struct pt_regs' frames have the two values inverted. It's almost sure that these values never matter, and that they also never differ. But wrong is wrong. Signed-off-by: Roland McGrath <roland@redhat.com>
2010-06-29kprobes/x86: Fix kprobes to skip prefixes correctlyMasami Hiramatsu
Fix resume_execution() and is_IF_modifier() to skip x86 instruction prefixes correctly by using x86 instruction attribute. Without this fix, resume_execution() can't handle instructions which have non-REX prefixes (REX prefixes are skipped). This will cause unexpected kernel panic by hitting bad address when a kprobe hits on two-byte ret (e.g. "repz ret" generated for Athlon/K8 optimization), because it just checks "repz" and can't recognize the "ret" instruction. These prefixes can be found easily with x86 instruction attribute. This patch introduces skip_prefixes() and uses it in resume_execution() and is_IF_modifier() to skip prefixes. Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> LKML-Reference: <4C298A6E.8070609@hitachi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-05-18Merge 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: (311 commits) perf tools: Add mode to build without newt support perf symbols: symbol inconsistency message should be done only at verbose=1 perf tui: Add explicit -lslang option perf options: Type check all the remaining OPT_ variants perf options: Type check OPT_BOOLEAN and fix the offenders perf options: Check v type in OPT_U?INTEGER perf options: Introduce OPT_UINTEGER perf tui: Add workaround for slang < 2.1.4 perf record: Fix bug mismatch with -c option definition perf options: Introduce OPT_U64 perf tui: Add help window to show key associations perf tui: Make <- exit menus too perf newt: Add single key shortcuts for zoom into DSO and threads perf newt: Exit browser unconditionally when CTRL+C, q or Q is pressed perf newt: Fix the 'A'/'a' shortcut for annotate perf newt: Make <- exit the ui_browser x86, perf: P4 PMU - fix counters management logic perf newt: Make <- zoom out filters perf report: Report number of events, not samples perf hist: Clarify events_stats fields usage ... Fix up trivial conflicts in kernel/fork.c and tools/perf/builtin-record.c
2010-05-11kprobes/x86: Fix removed int3 checking orderMasami Hiramatsu
Fix kprobe/x86 to check removed int3 when failing to get kprobe from hlist. Since we have a time window between checking int3 exists on probed address and getting kprobe on that address, we can have following scenario: ------- CPU1 CPU2 hit int3 check int3 exists remove int3 remove kprobe from hlist get kprobe from hlist no kprobe->OOPS! ------- This patch moves int3 checking if there is no kprobe on that address for fixing this problem as follows: ------ CPU1 CPU2 hit int3 remove int3 remove kprobe from hlist get kprobe from hlist no kprobe->check int3 exists ->rollback&retry ------ Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com> Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: systemtap <systemtap@sources.redhat.com> Cc: DLE <dle-develop@lists.sourceforge.net> Cc: Dave Anderson <anderson@redhat.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <20100427223348.2322.9112.stgit@localhost6.localdomain6> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-03-26x86, ptrace: Fix block-stepPeter Zijlstra
Implement ptrace-block-step using TIF_BLOCKSTEP which will set DEBUGCTLMSR_BTF when set for a task while preserving any other DEBUGCTLMSR bits. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20100325135414.017536066@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-03-26x86, perf, bts, mm: Delete the never used BTS-ptrace codePeter Zijlstra
Support for the PMU's BTS features has been upstreamed in v2.6.32, but we still have the old and disabled ptrace-BTS, as Linus noticed it not so long ago. It's buggy: TIF_DEBUGCTLMSR is trampling all over that MSR without regard for other uses (perf) and doesn't provide the flexibility needed for perf either. Its users are ptrace-block-step and ptrace-bts, since ptrace-bts was never used and ptrace-block-step can be implemented using a much simpler approach. So axe all 3000 lines of it. That includes the *locked_memory*() APIs in mm/mlock.c as well. Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Roland McGrath <roland@redhat.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Markus Metzger <markus.t.metzger@intel.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Andrew Morton <akpm@linux-foundation.org> LKML-Reference: <20100325135413.938004390@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-02-25kprobes/x86: Support kprobes jump optimization on x86Masami Hiramatsu
Introduce x86 arch-specific optimization code, which supports both of x86-32 and x86-64. This code also supports safety checking, which decodes whole of a function in which probe is inserted, and checks following conditions before optimization: - The optimized instructions which will be replaced by a jump instruction don't straddle the function boundary. - There is no indirect jump instruction, because it will jumps into the address range which is replaced by jump operand. - There is no jump/loop instruction which jumps into the address range which is replaced by jump operand. - Don't optimize kprobes if it is in functions into which fixup code will jumps. This uses text_poke_multibyte() which doesn't support modifying code on NMI/MCE handler. However, since kprobes itself doesn't support NMI/MCE code probing, it's not a problem. Changes in v9: - Use *_text_reserved() for checking the probe can be optimized. - Verify jump address range is in 2G range when preparing slot. - Backup original code when switching optimized buffer, instead of preparing buffer, because there can be int3 of other probes in preparing phase. - Check kprobe is disabled in arch_check_optimized_kprobe(). - Strictly check indirect jump opcodes (ff /4, ff /5). Changes in v6: - Split stop_machine-based jump patching code. - Update comments and coding style. Changes in v5: - Introduce stop_machine-based jump replacing. 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: <20100225133446.6725.78994.stgit@localhost6.localdomain6> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-02-25kprobes/x86: Cleanup save/restore registersMasami Hiramatsu
Introduce SAVE/RESOTRE_REGS_STRING for cleanup kretprobe-trampoline asm code. These macros will be used for emulating interruption. 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: <20100225133430.6725.83342.stgit@localhost6.localdomain6> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-02-25kprobes/x86: Boost probes when reenteringMasami Hiramatsu
Integrate prepare_singlestep() into setup_singlestep() to boost up reenter probes, if possible. 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: <20100225133423.6725.12071.stgit@localhost6.localdomain6> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-02-25kprobes/x86: Cleanup RELATIVEJUMP_INSTRUCTION to RELATIVEJUMP_OPCODEMasami Hiramatsu
Change RELATIVEJUMP_INSTRUCTION macro to RELATIVEJUMP_OPCODE since it represents just the opcode byte. Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com> Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.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: <20100225133349.6725.99302.stgit@localhost6.localdomain6> 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>
2009-12-07Merge branch 'for-next' into for-linusJiri Kosina
Conflicts: kernel/irq/chip.c
2009-12-05Merge branch 'x86-cleanups-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: x86: Fix a section mismatch in arch/x86/kernel/setup.c x86: Fixup last users of irq_chip->typename x86: Remove BKL from apm_32 x86: Remove BKL from microcode x86: use kernel_stack_pointer() in kprobes.c x86: use kernel_stack_pointer() in kgdb.c x86: use kernel_stack_pointer() in dumpstack.c x86: use kernel_stack_pointer() in process_32.c
2009-12-04tree-wide: fix assorted typos all over the placeAndré Goddard Rosa
That is "success", "unknown", "through", "performance", "[re|un]mapping" , "access", "default", "reasonable", "[con]currently", "temperature" , "channel", "[un]used", "application", "example","hierarchy", "therefore" , "[over|under]flow", "contiguous", "threshold", "enough" and others. Signed-off-by: André Goddard Rosa <andre.goddard@gmail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2009-11-21Merge branch 'tracing/hw-breakpoints' into perf/coreIngo Molnar
Conflicts: arch/x86/kernel/kprobes.c kernel/trace/Makefile Merge reason: hw-breakpoints perf integration is looking good in testing and in reviews, plus conflicts are mounting up - so merge & resolve. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-10-12x86: use kernel_stack_pointer() in kprobes.cH. Peter Anvin
The way to obtain a kernel-mode stack pointer from a struct pt_regs in 32-bit mode is "subtle": the stack doesn't actually contain the stack pointer, but rather the location where it would have been marks the actual previous stack frame. For clarity, use kernel_stack_pointer() instead of coding this weirdness explicitly. Signed-off-by: H. Peter Anvin <hpa@zytor.com> Cc: 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>
2009-08-30kprobes/x86-64: Allow to reenter probe on post_handlerMasami Hiramatsu
Allow to reenter probe on the post_handler of another probe on x86-64, because x86-64 already allows reentering int3. In that case, reentered probe just increases kp.nmissed and returns. 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: <20090827172304.8246.4822.stgit@localhost.localdomain> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2009-08-30kprobes/x86: Call BUG() when reentering probe into KPROBES_HIT_SSMasami Hiramatsu
Call BUG() when a probe have been hit on the way of kprobe processing path, because that kind of probes are currently unrecoverable (recovering it will cause an infinite loop and stack overflow). The original code seems to assume that it's caused by an int3 which another subsystem inserted on out-of-line singlestep buffer if the hitting probe is same as current probe. However, in that case, int3-hitting-address is on the out-of-line buffer and should be different from first (current) int3 address. Thus, I decided to remove the code. I also removes arch_disarm_kprobe() because it will involve other stuffs in text_poke(). 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: <20090827172258.8246.61889.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>
2009-08-27kprobes: Cleanup fix_riprel() using insn decoder on x86Masami Hiramatsu
Cleanup fix_riprel() in arch/x86/kernel/kprobes.c by using the new x86 instruction decoder instead of using comparisons with raw ad hoc numeric opcodes. Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Avi Kivity <avi@redhat.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Frank Ch. Eigler <fche@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Jason Baron <jbaron@redhat.com> Cc: Jim Keniston <jkenisto@us.ibm.com> Cc: K.Prasad <prasad@linux.vnet.ibm.com> Cc: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Przemysław Pawełczyk <przemyslaw@pawelczyk.it> Cc: Roland McGrath <roland@redhat.com> Cc: Sam Ravnborg <sam@ravnborg.org> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Tom Zanussi <tzanussi@gmail.com> Cc: Vegard Nossum <vegard.nossum@gmail.com> LKML-Reference: <20090813203436.31965.34374.stgit@localhost.localdomain> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2009-08-27kprobes: Checks probe address is instruction boudary on x86Masami Hiramatsu
Ensure safeness of inserting kprobes by checking whether the specified address is at the first byte of an instruction on x86. This is done by decoding probed function from its head to the probe point. Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com> Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Avi Kivity <avi@redhat.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Frank Ch. Eigler <fche@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Jason Baron <jbaron@redhat.com> Cc: Jim Keniston <jkenisto@us.ibm.com> Cc: K.Prasad <prasad@linux.vnet.ibm.com> Cc: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Przemysław Pawełczyk <przemyslaw@pawelczyk.it> Cc: Roland McGrath <roland@redhat.com> Cc: Sam Ravnborg <sam@ravnborg.org> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Tom Zanussi <tzanussi@gmail.com> Cc: Vegard Nossum <vegard.nossum@gmail.com> LKML-Reference: <20090813203428.31965.21939.stgit@localhost.localdomain> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2009-06-02hw-breakpoints: reset bits in dr6 after the corresponding exception is handledK.Prasad
This patch resets the bit in dr6 after the corresponding exception is handled in code, so that we keep a clean track of the current virtual debug status register. [ Impact: keep track of breakpoints triggering completion ] Signed-off-by: K.Prasad <prasad@linux.vnet.ibm.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2009-04-02Merge branch 'tracing/core-v2' into tracing-for-linusIngo Molnar
Conflicts: include/linux/slub_def.h lib/Kconfig.debug mm/slob.c mm/slub.c
2009-03-25x86: kretprobe-booster interrupt emulation code fixMasami Hiramatsu
Fix interrupt emulation code in kretprobe-booster according to pt_regs update (es/ds change and gs adding). This issue has been reported on systemtap-bugzilla: http://sources.redhat.com/bugzilla/show_bug.cgi?id=9965 | On a -tip kernel on x86_32, kretprobe_example (from samples) triggers the | following backtrace when its retprobing a class of functions that cause a | copy_from/to_user(). | | BUG: sleeping function called from invalid context at mm/memory.c:3196 | in_atomic(): 0, irqs_disabled(): 1, pid: 2286, name: cat Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com> Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Tested-by: Bharata B Rao <bharata@linux.vnet.ibm.com> Cc: systemtap-ml <systemtap@sources.redhat.com> LKML-Reference: <49C7995C.2010601@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-18x86: kprobes.c fix compilation warningJaswinder Singh Rajput
arch/x86/kernel/kprobes.c:196: warning: passing argument 1 of ‘search_exception_tables’ makes integer from pointer without a cast Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> LKML-Reference:<49BED952.2050809@redhat.com> LKML-Reference: <1237378065.13488.2.camel@localhost.localdomain> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-17prevent boosting kprobes on exception addressMasami Hiramatsu
Don't boost at the addresses which are listed on exception tables, because major page fault will occur on those addresses. In that case, kprobes can not ensure that when instruction buffer can be freed since some processes will sleep on the buffer. kprobes-ia64 already has same check. Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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>
2009-01-07Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (24 commits) trivial: chack -> check typo fix in main Makefile trivial: Add a space (and a comma) to a printk in 8250 driver trivial: Fix misspelling of "firmware" in docs for ncr53c8xx/sym53c8xx trivial: Fix misspelling of "firmware" in powerpc Makefile trivial: Fix misspelling of "firmware" in usb.c trivial: Fix misspelling of "firmware" in qla1280.c trivial: Fix misspelling of "firmware" in a100u2w.c trivial: Fix misspelling of "firmware" in megaraid.c trivial: Fix misspelling of "firmware" in ql4_mbx.c trivial: Fix misspelling of "firmware" in acpi_memhotplug.c trivial: Fix misspelling of "firmware" in ipw2100.c trivial: Fix misspelling of "firmware" in atmel.c trivial: Fix misspelled firmware in Kconfig trivial: fix an -> a typos in documentation and comments trivial: fix then -> than typos in comments and documentation trivial: update Jesper Juhl CREDITS entry with new email trivial: fix singal -> signal typo trivial: Fix incorrect use of "loose" in event.c trivial: printk: fix indentation of new_text_line declaration trivial: rtc-stk17ta8: fix sparse warning ...
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>
2009-01-06trivial: fix then -> than typos in comments and documentationFrederik Schwarzer
- (better, more, bigger ...) then -> (...) than Signed-off-by: Frederik Schwarzer <schwarzerf@gmail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
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>
2008-07-15Kprobe smoke test lockdep warningPeter Zijlstra
On Mon, 2008-04-21 at 18:54 -0400, Masami Hiramatsu wrote: > Thank you for reporting. > > Actually, kprobes tries to fixup thread's flags in post_kprobe_handler > (which is called from kprobe_exceptions_notify) by > trace_hardirqs_fixup_flags(pt_regs->flags). However, even the irq flag > is set in pt_regs->flags, true hardirq is still off until returning > from do_debug. Thus, lockdep assumes that hardirq is off without annotation. > > IMHO, one possible solution is that fixing hardirq flags right after > notify_die in do_debug instead of in post_kprobe_handler. My reply to BZ 10489: > [ 2.707509] Kprobe smoke test started > [ 2.709300] ------------[ cut here ]------------ > [ 2.709420] WARNING: at kernel/lockdep.c:2658 check_flags+0x4d/0x12c() > [ 2.709541] Modules linked in: > [ 2.709588] Pid: 1, comm: swapper Not tainted 2.6.25.jml.057 #1 > [ 2.709588] [<c0126acc>] warn_on_slowpath+0x41/0x51 > [ 2.709588] [<c010bafc>] ? save_stack_trace+0x1d/0x3b > [ 2.709588] [<c0140a83>] ? save_trace+0x37/0x89 > [ 2.709588] [<c011987d>] ? kernel_map_pages+0x103/0x11c > [ 2.709588] [<c0109803>] ? native_sched_clock+0xca/0xea > [ 2.709588] [<c0142958>] ? mark_held_locks+0x41/0x5c > [ 2.709588] [<c0382580>] ? kprobe_exceptions_notify+0x322/0x3af > [ 2.709588] [<c0142aff>] ? trace_hardirqs_on+0xf1/0x119 > [ 2.709588] [<c03825b3>] ? kprobe_exceptions_notify+0x355/0x3af > [ 2.709588] [<c0140823>] check_flags+0x4d/0x12c > [ 2.709588] [<c0143c9d>] lock_release+0x58/0x195 > [ 2.709588] [<c038347c>] ? __atomic_notifier_call_chain+0x0/0x80 > [ 2.709588] [<c03834d6>] __atomic_notifier_call_chain+0x5a/0x80 > [ 2.709588] [<c0383508>] atomic_notifier_call_chain+0xc/0xe > [ 2.709588] [<c013b6d4>] notify_die+0x2d/0x2f > [ 2.709588] [<c038168a>] do_debug+0x67/0xfe > [ 2.709588] [<c0381287>] debug_stack_correct+0x27/0x30 > [ 2.709588] [<c01564c0>] ? kprobe_target+0x1/0x34 > [ 2.709588] [<c0156572>] ? init_test_probes+0x50/0x186 > [ 2.709588] [<c04fae48>] init_kprobes+0x85/0x8c > [ 2.709588] [<c04e947b>] kernel_init+0x13d/0x298 > [ 2.709588] [<c04e933e>] ? kernel_init+0x0/0x298 > [ 2.709588] [<c04e933e>] ? kernel_init+0x0/0x298 > [ 2.709588] [<c0105ef7>] kernel_thread_helper+0x7/0x10 > [ 2.709588] ======================= > [ 2.709588] ---[ end trace 778e504de7e3b1e3 ]--- > [ 2.709588] possible reason: unannotated irqs-off. > [ 2.709588] irq event stamp: 370065 > [ 2.709588] hardirqs last enabled at (370065): [<c0382580>] kprobe_exceptions_notify+0x322/0x3af > [ 2.709588] hardirqs last disabled at (370064): [<c0381bb7>] do_int3+0x1d/0x7d > [ 2.709588] softirqs last enabled at (370050): [<c012b464>] __do_softirq+0xfa/0x100 > [ 2.709588] softirqs last disabled at (370045): [<c0107438>] do_softirq+0x74/0xd9 > [ 2.714751] Kprobe smoke test passed successfully how I love this stuff... Ok, do_debug() is a trap, this can happen at any time regardless of the machine's IRQ state. So the first thing we do is fix up the IRQ state. Then we call this die notifier stuff; and return with messed up IRQ state... YAY. So, kprobes fudges it.. notify_die(DIE_DEBUG) kprobe_exceptions_notify() post_kprobe_handler() modify regs->flags trace_hardirqs_fixup_flags(regs->flags); <--- must be it So what's the use of modifying flags if they're not meant to take effect at some point. /me tries to reproduce issue; enable kprobes test thingy && boot OK, that reproduces.. So the below makes it work - but I'm not getting this code; at the time I wrote that stuff I CC'ed each and every kprobe maintainer listed in the usual places but got no reposonse - can some please explain this stuff to me? Are the saved flags only for the TF bit or are they made in full effect later (and if so, where) ? Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Masami Hiramatsu <mhiramat@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-17x86: replace most VM86 flags with flags from processor-flags.hgorcunov@gmail.com
Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-17x86, kprobes: correct post-eip value in post_hander()Yakov Lerner
I was trying to get the address of instruction to be executed next after the kprobed instruction. But regs->eip in post_handler() contains value which is useless to the user. It's pre-corrected value. This value is difficult to use without access to resume_execution(), which is not exported anyway. I moved the invocation of post_handler() to *after* resume_execution(). Now regs->eip contains meaningful value in post_handler(). I do not think this change breaks any backward-compatibility. To make meaning of the old value, post_handler() would need access to resume_execution() which is not exported. I have difficulty to believe that previous, uncorrected, regs->eip can be meaningfully used in post_handler(). Signed-off-by: Yakov Lerner <iler.ml@gmail.com> Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Acked-by: Masami Hiramatsu <mhiramat@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-17x86: prevent unconditional writes to DebugCtl MSRJan Beulich
Otherwise, enabling (or better, subsequent disabling) of single stepping would cause a kernel oops on CPUs not having this MSR. The patch could have been added a conditional to the MSR write in user_disable_single_step(), but centralizing the updates seems safer and (looking forward) better manageable. Signed-off-by: Jan Beulich <jbeulich@novell.com> Cc: Markus Metzger <markus.t.metzger@intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-19x86, kprobes: remove sparse warnings from x86Harvey Harrison
arch/x86/kernel/kprobes.c:584:16: warning: symbol 'kretprobe_trampoline_holder' was not declared. Should it be static? arch/x86/kernel/kprobes.c:676:6: warning: symbol 'trampoline_handler' was not declared. Should it be static? Make them static and add the __used attribute, approach taken from the arm kprobes implementation. kretprobe_trampoline_holder uses inline assemly to define the global symbol kretprobe_trampoline, but nothing ever calls the holder explicitly. trampoline handler is only called from inline assembly in the same file, mark it used and static. Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Acked-by: Masami Hiramatsu <mhiramat@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30x86: remove unneded castsJan Engelhardt
x86: remove unneeded casts Signed-off-by: Jan Engelhardt <jengelh@computergmbh.de> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30x86: fix singlestep handling in reenter_kprobeAbhishek Sagar
Highlight peculiar cases in singles-step kprobe handling. In reenter_kprobe(), a breakpoint in KPROBE_HIT_SS case can only occur when single-stepping a breakpoint on which a probe was installed. Since such probes are single-stepped inline, identifying these cases is unambiguous. All other cases leading up to KPROBE_HIT_SS are possible bugs. Identify and WARN_ON such cases. Signed-off-by: Abhishek Sagar <sagar.abhishek@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30x86: use wrmsrl in kprobes.c, step.cHarvey Harrison
Where x86_32 passed zero in the high 32 bits, use wrmsrl which will zero extend for us. This allows ifdefs for 32/64 bit to be eliminated. Eliminate ifdef in step.c. Similar cleanup was done when unifying kprobes_32|64.c and wrmsr() was chosen there over wrmsrl(). This patch changes these to wrmsrl. Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30x86: trivial whitespace in kprobes.cHarvey Harrison
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Acked-by: Masami Hiramatsu <mhiramat@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30x86: kprobes change kprobe_handler flowAbhishek Sagar
Signed-off-by: Abhishek Sagar <sagar.abhishek@gmail.com> Signed-off-by: Quentin Barnes <qbarnes@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30x86: code clarification patch to Kprobes arch codeQuentin Barnes
When developing the Kprobes arch code for ARM, I ran across some code found in x86 and s390 Kprobes arch code which I didn't consider as good as it could be. Once I figured out what the code was doing, I changed the code for ARM Kprobes to work the way I felt was more appropriate. I've tested the code this way in ARM for about a year and would like to push the same change to the other affected architectures. The code in question is in kprobe_exceptions_notify() which does: ==== /* kprobe_running() needs smp_processor_id() */ preempt_disable(); if (kprobe_running() && kprobe_fault_handler(args->regs, args->trapnr)) ret = NOTIFY_STOP; preempt_enable(); ==== For the moment, ignore the code having the preempt_disable()/ preempt_enable() pair in it. The problem is that kprobe_running() needs to call smp_processor_id() which will assert if preemption is enabled. That sanity check by smp_processor_id() makes perfect sense since calling it with preemption enabled would return an unreliable result. But the function kprobe_exceptions_notify() can be called from a context where preemption could be enabled. If that happens, the assertion in smp_processor_id() happens and we're dead. So what the original author did (speculation on my part!) is put in the preempt_disable()/preempt_enable() pair to simply defeat the check. Once I figured out what was going on, I considered this an inappropriate approach. If kprobe_exceptions_notify() is called from a preemptible context, we can't be in a kprobe processing context at that time anyways since kprobes requires preemption to already be disabled, so just check for preemption enabled, and if so, blow out before ever calling kprobe_running(). I wrote the ARM kprobe code like this: ==== /* To be potentially processing a kprobe fault and to * trust the result from kprobe_running(), we have * be non-preemptible. */ if (!preemptible() && kprobe_running() && kprobe_fault_handler(args->regs, args->trapnr)) ret = NOTIFY_STOP; ==== The above code has been working fine for ARM Kprobes for a year. So I changed the x86 code (2.6.24-rc6) to be the same way and ran the Systemtap tests on that kernel. As on ARM, Systemtap on x86 comes up with the same test results either way, so it's a neutral external functional change (as expected). This issue has been discussed previously on linux-arm-kernel and the Systemtap mailing lists. Pointers to the by base for the two discussions: http://lists.arm.linux.org.uk/lurker/message/20071219.223225.1f5c2a5e.en.html http://sourceware.org/ml/systemtap/2007-q1/msg00251.html Signed-off-by: Quentin Barnes <qbarnes@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Ananth N Mavinakayahanalli <ananth@in.ibm.com> Acked-by: Ananth N Mavinakayahanalli <ananth@in.ibm.com>
2008-01-30x86: kprobes change kprobe_handler flowHarvey Harrison
Make the control flow of kprobe_handler more obvious. Collapse the separate if blocks/gotos with if/else blocks this unifies the duplication of the check for a breakpoint instruction race with another cpu. Create two jump targets: preempt_out: re-enables preemption before returning ret out: only returns ret Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30x86: kprobes remove fix_riprel #ifdefHarvey Harrison
Move #ifdef around function definiton into the function and unconditionally return on X86_32. Saves an ifdef from the one callsite. [ mingo@elte.hu: minor cleanup. ] Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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