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path: root/Documentation/trace/uprobetracer.txt
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2014-01-02tracing/uprobes: Add @+file_offset fetch methodNamhyung Kim
Enable to fetch data from a file offset. Currently it only supports fetching from same binary uprobe set. It'll translate the file offset to a proper virtual address in the process. The syntax is "@+OFFSET" as it does similar to normal memory fetching (@ADDR) which does no address translation. Suggested-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Acked-by: Oleg Nesterov <oleg@redhat.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: zhangwei(Jovi) <jovi.zhangwei@huawei.com> Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net> Signed-off-by: Namhyung Kim <namhyung@kernel.org>
2014-01-02tracing/uprobes: Add support for full argument access methodsNamhyung Kim
Enable to fetch other types of argument for the uprobes. IOW, we can access stack, memory, deref, bitfield and retval from uprobes now. The format for the argument types are same as kprobes (but @SYMBOL type is not supported for uprobes), i.e: @ADDR : Fetch memory at ADDR $stackN : Fetch Nth entry of stack (N >= 0) $stack : Fetch stack address $retval : Fetch return value +|-offs(FETCHARG) : Fetch memory at FETCHARG +|- offs address Note that the retval only can be used with uretprobes. Original-patch-by: Hyeoncheol Lee <cheol.lee@lge.com> Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Acked-by: Oleg Nesterov <oleg@redhat.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: zhangwei(Jovi) <jovi.zhangwei@huawei.com> Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net> Signed-off-by: Hyeoncheol Lee <cheol.lee@lge.com> Signed-off-by: Namhyung Kim <namhyung@kernel.org>
2014-01-02tracing/uprobes: Fix documentation of uprobe registration syntaxNamhyung Kim
The uprobe syntax requires an offset after a file path not a symbol. Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Acked-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: zhangwei(Jovi) <jovi.zhangwei@huawei.com> Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net> Signed-off-by: Namhyung Kim <namhyung@kernel.org>
2013-04-13uretprobes: Documentation updateAnton Arapov
add the uretprobe syntax and update an example Signed-off-by: Anton Arapov <anton@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Signed-off-by: Oleg Nesterov <oleg@redhat.com>
2012-05-08tracing: Fix kconfig warning due to a typoSrikar Dronamraju
Commit f3f096cfe ("tracing: Provide trace events interface for uprobes") throws a warning about unmet dependencies. The exact warning message is: warning: (UPROBE_EVENT) selects UPROBES which has unmet direct dependencies (UPROBE_EVENTS && PERF_EVENTS) This is due to a typo in arch/Kconfig file. Fix similar typos in the uprobetracer documentation. Also add sample format of a uprobe event in the uprobetracer documentation as suggested by Masami Hiramatsu. Reported-by: Stephen Boyd <sboyd@codeaurora.org> Reported-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Anton Arapov <anton@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20120508111126.21004.38285.sendpatchset@srdronam.in.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-05-07tracing: Provide trace events interface for uprobesSrikar Dronamraju
Implements trace_event support for uprobes. In its current form it can be used to put probes at a specified offset in a file and dump the required registers when the code flow reaches the probed address. The following example shows how to dump the instruction pointer and %ax a register at the probed text address. Here we are trying to probe zfree in /bin/zsh: # cd /sys/kernel/debug/tracing/ # cat /proc/`pgrep zsh`/maps | grep /bin/zsh | grep r-xp 00400000-0048a000 r-xp 00000000 08:03 130904 /bin/zsh # objdump -T /bin/zsh | grep -w zfree 0000000000446420 g DF .text 0000000000000012 Base zfree # echo 'p /bin/zsh:0x46420 %ip %ax' > uprobe_events # cat uprobe_events p:uprobes/p_zsh_0x46420 /bin/zsh:0x0000000000046420 # echo 1 > events/uprobes/enable # sleep 20 # echo 0 > events/uprobes/enable # cat trace # tracer: nop # # TASK-PID CPU# TIMESTAMP FUNCTION # | | | | | zsh-24842 [006] 258544.995456: p_zsh_0x46420: (0x446420) arg1=446421 arg2=79 zsh-24842 [007] 258545.000270: p_zsh_0x46420: (0x446420) arg1=446421 arg2=79 zsh-24842 [002] 258545.043929: p_zsh_0x46420: (0x446420) arg1=446421 arg2=79 zsh-24842 [004] 258547.046129: p_zsh_0x46420: (0x446420) arg1=446421 arg2=79 Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Acked-by: Steven Rostedt <rostedt@goodmis.org> Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Jim Keniston <jkenisto@linux.vnet.ibm.com> Cc: Linux-mm <linux-mm@kvack.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Christoph Hellwig <hch@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Anton Arapov <anton@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20120411103043.GB29437@linux.vnet.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>