1. 03 2月, 2016 1 次提交
    • H
      perf probe: Search both .eh_frame and .debug_frame sections for probe location · 270bde1e
      Hemant Kumar 提交于
      'perf probe' through debuginfo__find_probes() in util/probe-finder.c
      checks for the functions' frame descriptions in either .eh_frame section
      of an ELF or the .debug_frame.
      
      The check is based on whether either one of these sections is present.
      Depending on distro, toolchain defaults, architetcutre, build flags,
      etc., CFI might be found in either .eh_frame and/or .debug_frame.
      Sometimes, it may happen that, .eh_frame, even if present, may not be
      complete and may miss some descriptions.
      
      Therefore, to be sure, to find the CFI covering an address we will
      always have to investigate both if available.
      
      For e.g., in powerpc, this may happen:
        $ gcc -g bin.c -o bin
      
        $ objdump --dwarf ./bin
        <1><145>: Abbrev Number: 7 (DW_TAG_subprogram)
           <146> DW_AT_external   : 1
           <146> DW_AT_name       : (indirect string, offset: 0x9e): main
           <14a> DW_AT_decl_file  : 1
           <14b> DW_AT_decl_line  : 39
           <14c> DW_AT_prototyped : 1
           <14c> DW_AT_type       : <0x57>
           <150> DW_AT_low_pc     : 0x100007b8
      
      If the .eh_frame and .debug_frame are checked for the same binary, we
      will find that, .eh_frame (although present) doesn't contain a
      description for "main" function.
      
      But, .debug_frame has a description:
      
        000000d8 00000024 00000000 FDE cie=00000000 pc=100007b8..10000838
          DW_CFA_advance_loc: 16 to 100007c8
          DW_CFA_def_cfa_offset: 144
          DW_CFA_offset_extended_sf: r65 at cfa+16
        ...
      
      Due to this (since, perf checks whether .eh_frame is present and goes on
      searching for that address inside that frame), perf is unable to process
      the probes:
      
        # perf probe -x ./bin main
          Failed to get call frame on 0x100007b8
          Error: Failed to add events.
      
      To avoid this issue, we need to check both the sections (.eh_frame and
      .debug_frame), which is done in this patch.
      
      Note that, we can always force everything into both .eh_frame and
      .debug_frame by:
      
        $ gcc bin.c -fasynchronous-unwind-tables  -fno-dwarf2-cfi-asm -g -o bin
      Signed-off-by: NHemant Kumar <hemant@linux.vnet.ibm.com>
      Acked-by: NMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
      Cc: linuxppc-dev@lists.ozlabs.org
      Cc: Mark Wielaard <mjw@redhat.com>
      Cc: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
      Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
      Link: http://lkml.kernel.org/r/1454426806-13974-1-git-send-email-hemant@linux.vnet.ibm.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      270bde1e
  2. 26 11月, 2015 1 次提交
  3. 20 11月, 2015 1 次提交
  4. 13 11月, 2015 2 次提交
    • W
      perf probe: Clear probe_trace_event when add_probe_trace_event() fails · 092b1f0b
      Wang Nan 提交于
      When probing with a glob, errors in add_probe_trace_event() won't be
      passed to debuginfo__find_trace_events() because it would be modified by
      probe_point_search_cb(). It causes a segfault if perf fails to find an
      argument for a probe point matched by the glob. For example:
      
        # ./perf probe -v -n 'SyS_dup? oldfd'
        probe-definition(0): SyS_dup? oldfd
        symbol:SyS_dup? file:(null) line:0 offset:0 return:0 lazy:(null)
        parsing arg: oldfd into oldfd
        1 arguments
        Looking at the vmlinux_path (7 entries long)
        Using /lib/modules/4.3.0-rc4+/build/vmlinux for symbols
        Open Debuginfo file: /lib/modules/4.3.0-rc4+/build/vmlinux
        Try to find probe point from debuginfo.
        Matched function: SyS_dup3
        found inline addr: 0xffffffff812095c0
        Probe point found: SyS_dup3+0
        Searching 'oldfd' variable in context.
        Converting variable oldfd into trace event.
        oldfd type is long int.
        found inline addr: 0xffffffff812096d4
        Probe point found: SyS_dup2+36
        Searching 'oldfd' variable in context.
        Failed to find 'oldfd' in this function.
        Matched function: SyS_dup3
        Probe point found: SyS_dup3+0
        Searching 'oldfd' variable in context.
        Converting variable oldfd into trace event.
        oldfd type is long int.
        Matched function: SyS_dup2
        Probe point found: SyS_dup2+0
        Searching 'oldfd' variable in context.
        Converting variable oldfd into trace event.
        oldfd type is long int.
        Found 4 probe_trace_events.
        Opening /sys/kernel/debug/tracing//kprobe_events write=1
        Writing event: p:probe/SyS_dup3 _text+2135488 oldfd=%di:s64
        Segmentation fault (core dumped)
        #
      
      This patch ensures that add_probe_trace_event() doesn't touches
      tf->ntevs and tf->tevs if those functions fail.
      
      After the patch:
      
        # perf probe  'SyS_dup? oldfd'
        Failed to find 'oldfd' in this function.
        Added new events:
          probe:SyS_dup3       (on SyS_dup? with oldfd)
          probe:SyS_dup3_1     (on SyS_dup? with oldfd)
          probe:SyS_dup2       (on SyS_dup? with oldfd)
      
        You can now use it in all perf tools, such as:
      
      	perf record -e probe:SyS_dup2 -aR sleep 1
      Signed-off-by: NWang Nan <wangnan0@huawei.com>
      Tested-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      Cc: Alexei Starovoitov <ast@kernel.org>
      Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
      Cc: Zefan Li <lizefan@huawei.com>
      Cc: pi3orama@163.com
      Link: http://lkml.kernel.org/r/1447417761-156094-3-git-send-email-wangnan0@huawei.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      092b1f0b
    • M
      perf probe: Fix memory leaking on failure by clearing all probe_trace_events · 0196e787
      Masami Hiramatsu 提交于
      Fix memory leaking on the debuginfo__find_trace_events() failure path
      which frees an array of probe_trace_events but doesn't clears all the
      allocated sub-structures and strings.
      
      So, before doing zfree(tevs), clear all the array elements which may
      have allocated resources.
      Reported-by: NWang Nan <wangnan0@huawei.com>
      Signed-off-by: NMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
      Cc: Alexei Starovoitov <ast@kernel.org>
      Cc: Zefan Li <lizefan@huawei.com>
      Cc: pi3orama@163.com
      Link: http://lkml.kernel.org/r/1447417761-156094-2-git-send-email-wangnan0@huawei.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      0196e787
  5. 01 10月, 2015 3 次提交
  6. 26 8月, 2015 1 次提交
    • W
      perf probe: Support probing at absolute address · da15bd9d
      Wang Nan 提交于
      It should be useful to allow 'perf probe' probe at absolute offset of a
      target. For example, when (u)probing at a instruction of a shared object
      in a embedded system where debuginfo is not avaliable but we know the
      offset of that instruction by manually digging.
      
      This patch enables following perf probe command syntax:
      
        # perf probe 0xffffffff811e6615
      
      And
      
        # perf probe /lib/x86_64-linux-gnu/libc-2.19.so 0xeb860
      
      In the above example, we don't need a anchor symbol, so it is possible
      to compute absolute addresses using other methods and then use 'perf
      probe' to create the probing points.
      
      v1 -> v2:
        Drop the leading '+' in cmdline;
        Allow uprobing at offset 0x0;
        Improve 'perf probe -l' result when uprobe at area without debuginfo.
      
      v2 -> v3:
        Split bugfix to a separated patch.
      
      Test result:
      
        # perf probe 0xffffffff8119d175 %ax
        # perf probe sys_write %ax
        # perf probe /lib64/libc-2.18.so 0x0 %ax
        # perf probe /lib64/libc-2.18.so 0x5 %ax
        # perf probe /lib64/libc-2.18.so 0xd8e40 %ax
        # perf probe /lib64/libc-2.18.so __write %ax
        # perf probe /lib64/libc-2.18.so 0xd8e49 %ax
        # cat /sys/kernel/debug/tracing/uprobe_events
      
        p:probe_libc/abs_0 /lib64/libc-2.18.so:0x          (null) arg1=%ax
        p:probe_libc/abs_5 /lib64/libc-2.18.so:0x0000000000000005 arg1=%ax
        p:probe_libc/abs_d8e40 /lib64/libc-2.18.so:0x00000000000d8e40 arg1=%ax
        p:probe_libc/__write /lib64/libc-2.18.so:0x00000000000d8e40 arg1=%ax
        p:probe_libc/abs_d8e49 /lib64/libc-2.18.so:0x00000000000d8e49 arg1=%ax
      
        # cat /sys/kernel/debug/tracing/kprobe_events
      
        p:probe/abs_ffffffff8119d175 0xffffffff8119d175 arg1=%ax
        p:probe/sys_write _text+1692016 arg1=%ax
      
        # perf probe -l
      
        Failed to find debug information for address 5
          probe:abs_ffffffff8119d175 (on sys_write+5 with arg1)
          probe:sys_write      (on sys_write with arg1)
          probe_libc:__write   (on @unix/syscall-template.S:81 in /lib64/libc-2.18.so with arg1)
          probe_libc:abs_0     (on 0x0 in /lib64/libc-2.18.so with arg1)
          probe_libc:abs_5     (on 0x5 in /lib64/libc-2.18.so with arg1)
          probe_libc:abs_d8e40 (on @unix/syscall-template.S:81 in /lib64/libc-2.18.so with arg1)
          probe_libc:abs_d8e49 (on __GI___libc_write+9 in /lib64/libc-2.18.so with arg1)
      Signed-off-by: NWang Nan <wangnan0@huawei.com>
      Acked-by: NMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
      Cc: Namhyung Kim <namhyung@kernel.org>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      Cc: Zefan Li <lizefan@huawei.com>
      Cc: pi3orama@163.com
      Link: http://lkml.kernel.org/r/1440586666-235233-7-git-send-email-wangnan0@huawei.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      da15bd9d
  7. 20 7月, 2015 1 次提交
  8. 08 6月, 2015 1 次提交
    • A
      perf tools: Reference count struct dso · d3a7c489
      Arnaldo Carvalho de Melo 提交于
      This has a different model than the 'thread' and 'map' struct lifetimes:
      there is not a definitive "don't use this DSO anymore" event, i.e. we may
      get many 'struct map' holding references to the '/usr/lib64/libc-2.20.so'
      DSO but then at some point some DSO may have no references but we still
      don't want to straight away release its resources, because "soon" we may
      get a new 'struct map' that needs it and we want to reuse its symtab or
      other resources.
      
      So we need some way to garbage collect it when crossing some memory
      usage threshold, which is left for anoter patch, for now it is
      sufficient to release it when calling dsos__exit(), i.e. when deleting
      the whole list as part of deleting the 'struct machine' containing it,
      which will leave only referenced objects being used.
      
      Cc: Adrian Hunter <adrian.hunter@intel.com>
      Cc: David Ahern <dsahern@gmail.com>
      Cc: Jiri Olsa <jolsa@redhat.com>
      Cc: Namhyung Kim <namhyung@kernel.org>
      Link: http://lkml.kernel.org/n/tip-majzgz07cm90t2tejrjy4clf@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      d3a7c489
  9. 14 5月, 2015 1 次提交
    • N
      perf probe: Ignore tail calls to probed functions · d4c537e6
      Naveen N. Rao 提交于
      perf probe currently errors out if there are any tail calls to probed
      functions:
      
      [root@rhel71be]# perf probe do_fork
      Failed to find probe point in any functions.
        Error: Failed to add events.
      
      Fix this by teaching perf to ignore tail calls.
      
      Without patch:
      
        [root@rhel71be perf]# ./perf probe -v do_fork
        probe-definition(0): do_fork symbol:do_fork file:(null) line:0 offset:0
        return:0 lazy:(null)
        0 arguments
        Looking at the vmlinux_path (7 entries long)
        symsrc__init: build id mismatch for /boot/vmlinux.
        Using /usr/lib/debug/lib/modules/3.10.0-201.el7.ppc64/vmlinux for symbols
        Open Debuginfo file:
        /usr/lib/debug/lib/modules/3.10.0-201.el7.ppc64/vmlinux
        Try to find probe point from debuginfo.
        found inline addr: 0xc0000000000bb9b0
        Probe point found: do_fork+0
        found inline addr: 0xc0000000000bbe20
        Probe point found: kernel_thread+48
        found inline addr: 0xc0000000000bbe5c
        Probe point found: sys_fork+28
        found inline addr: 0xc0000000000bbfac
        Probe point found: sys_vfork+44
        found inline addr: 0xc0000000000bc27c
        Failed to find probe point in any functions.
        An error occurred in debuginfo analysis (-2).
        Error: Failed to add events. Reason: No such file or directory (Code: -2)
      
      With patch:
      
        [root@rhel71be perf]# ./perf probe -v do_fork
        probe-definition(0): do_fork symbol:do_fork file:(null) line:0 offset:0
        return:0 lazy:(null)
        0 arguments
        Looking at the vmlinux_path (7 entries long)
        symsrc__init: build id mismatch for /boot/vmlinux.
        Using /usr/lib/debug/lib/modules/3.10.0-201.el7.ppc64/vmlinux for symbols
        Open Debuginfo file:
        /usr/lib/debug/lib/modules/3.10.0-201.el7.ppc64/vmlinux
        Try to find probe point from debuginfo.
        found inline addr: 0xc0000000000bb9b0
        Probe point found: do_fork+0
        found inline addr: 0xc0000000000bbe20
        Probe point found: kernel_thread+48
        found inline addr: 0xc0000000000bbe5c
        Probe point found: sys_fork+28
        found inline addr: 0xc0000000000bbfac
        Probe point found: sys_vfork+44
        found inline addr: 0xc0000000000bc27c
        Ignoring tail call from SyS_clone
        Found 4 probe_trace_events.
        Opening /sys/kernel/debug/tracing/kprobe_events write=1
        No kprobe blacklist support, ignored
        Added new events:
        Writing event: p:probe/do_fork _text+768432
        Failed to write event: Invalid argument
          Error: Failed to add events. Reason: Invalid argument (Code: -22)
      
      [Ignore the error about failure to write event - this kernel is missing
      a patch to resolve _text properly]
      
      The reason to ignore tail calls is that the address does not belong to
      any function frame. In the example above, the address in SyS_clone is
      0xc0000000000bc27c, but looking at the debug-info:
      
       <1><830081>: Abbrev Number: 133 (DW_TAG_subprogram)
          <830083>   DW_AT_external    : 1
          <830083>   DW_AT_name        : (indirect string, offset: 0x3cea3): SyS_clone
          <830087>   DW_AT_decl_file   : 7
          <830088>   DW_AT_decl_line   : 1689
          <83008a>   DW_AT_prototyped  : 1
          <83008a>   DW_AT_type        : <0x8110eb>
          <83008e>   DW_AT_low_pc      : 0xc0000000000bc270
          <830096>   DW_AT_high_pc     : 0xc
          <83009e>   DW_AT_frame_base  : 1 byte block: 9c 	(DW_OP_call_frame_cfa)
          <8300a0>   DW_AT_GNU_all_call_sites: 1
          <8300a0>   DW_AT_sibling     : <0x830178>
      <snip>
       <3><830147>: Abbrev Number: 125 (DW_TAG_GNU_call_site)
          <830148>   DW_AT_low_pc      : 0xc0000000000bc27c
          <830150>   DW_AT_GNU_tail_call: 1
          <830150>   DW_AT_abstract_origin: <0x82e7e1>
      
      The frame ends at 0xc0000000000bc27c. I suppose this is why this
      particular call is a "tail" call. FWIW, systemtap seems to ignore these
      as well and requires users to explicitly place probes at these call
      sites if necessary. I print out the caller so that users know.
      Signed-off-by: NNaveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
      Acked-by: NMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
      Link: http://lkml.kernel.org/r/1430394151-15928-1-git-send-email-naveen.n.rao@linux.vnet.ibm.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      d4c537e6
  10. 12 5月, 2015 3 次提交
    • H
      perf probe: Show better error message when failed to find variable · 7d5eaba9
      He Kuang 提交于
      Indicate to check variable location range in error message when we got
      failed to find the variable.
      
      Before this patch:
      
        $ perf probe --add 'generic_perform_write+118 bytes'
        Failed to find the location of bytes at this address.
         Perhaps, it has been optimized out.
          Error: Failed to add events.
      
      After this patch:
      
        $ perf probe --add 'generic_perform_write+118 bytes'
        Failed to find the location of the 'bytes' variable at this address.
         Perhaps it has been optimized out.
         Use -V with the --range option to show 'bytes' location range.
          Error: Failed to add events.
      Signed-off-by: NHe Kuang <hekuang@huawei.com>
      Acked-by: NMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
      Cc: Jiri Olsa <jolsa@kernel.org>
      Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
      Cc: Wang Nan <wangnan0@huawei.com>
      Link: http://lkml.kernel.org/r/1431336304-16863-3-git-send-email-hekuang@huawei.com
      [ Improve the error message based on lkml thread ]
      Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      7d5eaba9
    • H
      perf probe: Add --range option to show a variable's location range · 349e8d26
      He Kuang 提交于
      It is not easy for users to get the accurate byte offset or the line
      number where a local variable can be probed.
      
      With '--range' option, local variables in the scope of the probe point
      are showed with a byte offset range, and can be added according to this
      range information.
      
      For example, there are some variables in the function
      generic_perform_write():
      
        <generic_perform_write@mm/filemap.c:0>
        0  ssize_t generic_perform_write(struct file *file,
        1                                 struct iov_iter *i, loff_t pos)
        2  {
        3          struct address_space *mapping = file->f_mapping;
        4          const struct address_space_operations *a_ops = mapping->a_ops;
        ...
        42                 status = a_ops->write_begin(file, mapping, pos, bytes, flags,
                                                     &page, &fsdata);
        44                 if (unlikely(status < 0))
      
      But we fail when we try to probe the variable 'a_ops' at line 42 or 44.
      
        $ perf probe --add 'generic_perform_write:42 a_ops'
        Failed to find the location of a_ops at this address.
          Perhaps, it has been optimized out.
      
      This is because the source code do not match the assembly, so a variable
      may not be available in the source code line where it appears.
      
      After this patch, we can lookup the accurate byte offset range of a
      variable, 'INV' indicates that this variable is not valid at the given
      point, but available in the scope:
      
        $ perf probe --vars 'generic_perform_write:42' --range
        Available variables at generic_perform_write:42
          @<generic_perform_write+141>
             [INV] ssize_t written @<generic_perform_write+[324-331]>
             [INV] struct address_space_operations*        a_ops   @<generic_perform_write+[55-61,170-176,223-246]>
             [VAL] (unknown_type)  fsdata  @<generic_perform_write+[70-307,346-411]>
             [VAL] loff_t  pos     @<generic_perform_write+[0-286,286-336,346-411]>
             [VAL] long int        status  @<generic_perform_write+[83-342,346-411]>
             [VAL] long unsigned int       bytes   @<generic_perform_write+[122-311,320-338,346-403,403-411]>
             [VAL] struct address_space*   mapping @<generic_perform_write+[35-344,346-411]>
             [VAL] struct iov_iter*        i       @<generic_perform_write+[0-340,346-411]>
             [VAL] struct page*    page    @<generic_perform_write+[70-307,346-411]>
      
      Then it is more clear for us to add a probe with this variable:
      
        $ perf probe --add 'generic_perform_write+170 a_ops'
        Added new event:
          probe:generic_perform_write (on generic_perform_write+170 with a_ops)
      Signed-off-by: NHe Kuang <hekuang@huawei.com>
      Acked-by: NMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
      Cc: Jiri Olsa <jolsa@kernel.org>
      Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
      Cc: Wang Nan <wangnan0@huawei.com>
      Link: http://lkml.kernel.org/r/1431336304-16863-2-git-send-email-hekuang@huawei.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      349e8d26
    • H
      perf probe: Remove length limitation for showing available variables · fb9596d1
      He Kuang 提交于
      Use struct strbuf instead of bare char[] to remove the length limitation
      of variables in variable_list, so they will not disappear due to
      overlength, and make preparation for adding more description for
      variables.
      Signed-off-by: NHe Kuang <hekuang@huawei.com>
      Acked-by: NMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
      Cc: Jiri Olsa <jolsa@kernel.org>
      Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
      Cc: Wang Nan <wangnan0@huawei.com>
      Link: http://lkml.kernel.org/r/1431336304-16863-1-git-send-email-hekuang@huawei.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      fb9596d1
  11. 09 5月, 2015 4 次提交
    • M
      perf probe: Support glob wildcards for function name · 4c859351
      Masami Hiramatsu 提交于
      Support glob wildcards for function name when adding new probes. This
      will allow us to build caches of function-entry level information with
      $params.
      
      e.g.
        ----
        # perf probe --no-inlines --add 'kmalloc* $params'
        Added new events:
          probe:kmalloc_slab   (on kmalloc* with $params)
          probe:kmalloc_large_node (on kmalloc* with $params)
          probe:kmalloc_order_trace (on kmalloc* with $params)
      
        You can now use it in all perf tools, such as:
      
              perf record -e probe:kmalloc_order_trace -aR sleep 1
      
        # perf probe --list
          probe:kmalloc_large_node (on kmalloc_large_node@mm/slub.c with size flags node)
          probe:kmalloc_order_trace (on kmalloc_order_trace@mm/slub.c with size flags order)
          probe:kmalloc_slab   (on kmalloc_slab@mm/slab_common.c with size flags)
        ----
      Signed-off-by: NMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
      Tested-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
      Cc: David Ahern <dsahern@gmail.com>
      Cc: Hemant Kumar <hemant@linux.vnet.ibm.com>
      Cc: Jiri Olsa <jolsa@redhat.com>
      Cc: Namhyung Kim <namhyung@kernel.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Link: http://lkml.kernel.org/r/20150508010335.24812.19972.stgit@localhost.localdomainSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      4c859351
    • M
      perf probe: Add --no-inlines option to avoid searching inline functions · 6cfd1f68
      Masami Hiramatsu 提交于
      Add --no-inlines(--inlines) option to avoid searching inline functions.
      
      Searching all functions which matches glob pattern can take a long time
      and find a lot of inline functions.
      
      With this option perf-probe searches target on the non-inlined
      functions.
      Signed-off-by: NMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
      Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
      Cc: David Ahern <dsahern@gmail.com>
      Cc: Hemant Kumar <hemant@linux.vnet.ibm.com>
      Cc: Jiri Olsa <jolsa@redhat.com>
      Cc: Namhyung Kim <namhyung@kernel.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Link: http://lkml.kernel.org/r/20150508010333.24812.86568.stgit@localhost.localdomainSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      6cfd1f68
    • M
      perf probe: Introduce probe_conf global configs · ddb2f58f
      Masami Hiramatsu 提交于
      Introduce probe_conf global configuration parameters for probe-event and
      probe-finder, and removes related parameters from APIs.
      Signed-off-by: NMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
      Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
      Cc: David Ahern <dsahern@gmail.com>
      Cc: Hemant Kumar <hemant@linux.vnet.ibm.com>
      Cc: Jiri Olsa <jolsa@redhat.com>
      Cc: Namhyung Kim <namhyung@kernel.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Link: http://lkml.kernel.org/r/20150508010330.24812.21095.stgit@localhost.localdomainSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      ddb2f58f
    • M
      perf probe: Support $params special probe argument · f8bffbf1
      Masami Hiramatsu 提交于
      $params is similar to $vars but matches only function parameters not
      local variables.
      
      Thus, this is useful for tracing function parameter changing or tracing
      function call with parameters.
      
      Testing it:
      
       # perf probe tcp_sendmsg '$params'
       Added new event:
        probe:tcp_sendmsg    (on tcp_sendmsg with $params)
      
       You can now use it in all perf tools, such as:
      
      	perf record -e probe:tcp_sendmsg -aR sleep 1
      
       # perf probe -l
        probe:tcp_sendmsg    (on tcp_sendmsg@acme/git/linux/net/ipv4/tcp.c with iocb sk msg size)
       # perf record -a -e probe:*
       press some random letters to generate TCP (sshd) traffic...
      
       ^C[ perf record: Woken up 1 times to write data ]
       [ perf record: Captured and wrote 0.223 MB perf.data (6 samples) ]
      
       # perf script
         sshd 6385 [2] 3.907529: probe:tcp_sendmsg: iocb=0xffff8800ac4cfe70 sk=0xffff88042196c140 msg=0xffff8800ac4cfda8 size=0x24
         sshd 6385 [2] 4.138973: probe:tcp_sendmsg: iocb=0xffff8800ac4cfe70 sk=0xffff88042196c140 msg=0xffff8800ac4cfda8 size=0x24
         sshd 6385 [2] 4.378966: probe:tcp_sendmsg: iocb=0xffff8800ac4cfe70 sk=0xffff88042196c140 msg=0xffff8800ac4cfda8 size=0x24
         sshd 6385 [2] 4.603681: probe:tcp_sendmsg: iocb=0xffff8800ac4cfe70 sk=0xffff88042196c140 msg=0xffff8800ac4cfda8 size=0x24
         sshd 6385 [2] 4.818455: probe:tcp_sendmsg: iocb=0xffff8800ac4cfe70 sk=0xffff88042196c140 msg=0xffff8800ac4cfda8 size=0x24
         sshd 6385 [2] 5.043603: probe:tcp_sendmsg: iocb=0xffff8800ac4cfe70 sk=0xffff88042196c140 msg=0xffff8800ac4cfda8 size=0x24
       # cat /sys/kernel/debug/tracing/events/probe/tcp_sendmsg/format
       name: tcp_sendmsg
       ID: 1927
       format:
         field:unsigned short common_type;	offset:0;	size:2;	signed:0;
         field:unsigned char common_flags;	offset:2;	size:1;	signed:0;
         field:unsigned char common_preempt_count;	offset:3;	size:1;	signed:0;
         field:int common_pid;	offset:4;	size:4;	signed:1;
      
         field:unsigned long __probe_ip;	offset:8;	size:8;	signed:0;
         field:u64 iocb;	offset:16;	size:8;	signed:0;
         field:u64 sk;	offset:24;	size:8;	signed:0;
         field:u64 msg;	offset:32;	size:8;	signed:0;
         field:u64 size;	offset:40;	size:8;	signed:0;
      
       print fmt: "(%lx) iocb=0x%Lx sk=0x%Lx msg=0x%Lx size=0x%Lx", REC->__probe_ip, REC->iocb, REC->sk, REC->msg, REC->size
       #
      
       Do some system wide tracing of this probe + write syscalls:
      
       # perf trace -e write --ev probe:* --filter-pids 6385
        462.612 (0.010 ms): bash/19153 write(fd: 1</dev/pts/1>, buf: 0x7f7556c78000, count: 29               ) = 29
        462.701 (0.027 ms): sshd/19152 write(fd: 3<socket:[63117]>, buf: 0x7f78dd12e160, count: 68           ) ...
        462.701 (        ): probe:tcp_sendmsg:(ffffffff8163db30) iocb=0xffff8803ebec7e70 sk=0xffff88042196ab80 msg=0xffff8803ebec7da8 size=0x44)
        462.710 (0.035 ms): sshd/19152  ... [continued]: write()) = 68
        462.787 (0.009 ms): bash/19153 write(fd: 2</dev/pts/1>, buf: 0x7f7556c77000, count: 22               ) = 22
        462.865 (0.002 ms): sshd/19152 write(fd: 3<socket:[63117]>, buf: 0x7f78dd12e160, count: 68           ) ...
        462.865 (        ): probe:tcp_sendmsg:(ffffffff8163db30) iocb=0xffff8803ebec7e70 sk=0xffff88042196ab80 msg=0xffff8803ebec7da8 size=0x44)
        462.873 (0.010 ms): sshd/19152  ... [continued]: write()) = 68
      Signed-off-by: NMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
      Tested-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
      Cc: David Ahern <dsahern@gmail.com>
      Cc: Hemant Kumar <hemant@linux.vnet.ibm.com>
      Cc: Jiri Olsa <jolsa@redhat.com>
      Cc: Namhyung Kim <namhyung@kernel.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Link: http://lkml.kernel.org/r/20150506124653.4961.59806.stgit@localhost.localdomain
      [ Add some examples to the changelog message showing how to use it ]
      Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      f8bffbf1
  12. 28 4月, 2015 1 次提交
    • H
      perf probe: Fix bug with global variables handling · d13855ef
      He Kuang 提交于
      There are missing curly braces which causes find_variable() return wrong
      value when probing with global variables.
      
      This problem can be reproduced as following:
      
        $ perf probe -v --add='generic_perform_write global_variable_for_test'
        ...
        Try to find probe point from debuginfo.
        Probe point found: generic_perform_write+0
        Searching 'global_variable_for_test' variable in context.
        An error occurred in debuginfo analysis (-2).
          Error: Failed to add events. Reason: No such file or directory (Code: -2)
      
      After this patch:
      
        $ perf probe -v --add='generic_perform_write global_variable_for_test'
        ...
        Converting variable global_variable_for_test into trace event.
        global_variable_for_test type is int.
        Found 1 probe_trace_events.
        Opening /sys/kernel/debug/tracing/kprobe_events write=1
        Added new event:
        Writing event: p:probe/generic_perform_write _stext+1237464
        global_variable_for_test=@global_variable_for_test+0:s32
          probe:generic_perform_write (on generic_perform_write with
          global_variable_for_test)
      
        You can now use it in all perf tools, such as:
      
            perf record -e probe:generic_perform_write -aR sleep 1
      Signed-off-by: NHe Kuang <hekuang@huawei.com>
      Acked-by: NMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
      Cc: Wang Nan <wangnan0@huawei.com>
      Link: http://lkml.kernel.org/r/1429949338-18678-1-git-send-email-hekuang@huawei.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      d13855ef
  13. 14 4月, 2015 2 次提交
  14. 03 4月, 2015 1 次提交
  15. 07 3月, 2015 1 次提交
  16. 02 3月, 2015 1 次提交
  17. 06 2月, 2015 1 次提交
  18. 02 1月, 2015 1 次提交
    • N
      perf probe: Fix crash in dwarf_getcfi_elf · 4093325f
      Namhyung Kim 提交于
      David reported that perf can segfault when adding an uprobe event like
      this:
      
        $ perf probe -x /lib64/libc-2.14.90.so -a 'malloc  size=%di'
      
        (gdb) bt
        #0  parse_eh_frame_hdr (hdr=0x0, hdr_size=2596, hdr_vaddr=71788,
            ehdr=0x7fffffffd390, eh_frame_vaddr=
            0x7fffffffd378, table_entries=0x8808d8, table_encoding=0x8808e0 "") at
            dwarf_getcfi_elf.c:79
        #1  0x000000385f81615a in getcfi_scn_eh_frame (hdr_vaddr=71788,
            hdr_scn=0x8839b0, shdr=0x7fffffffd2f0, scn=<optimized out>,
            ehdr=0x7fffffffd390, elf=0x882b30) at dwarf_getcfi_elf.c:231
        #2  getcfi_shdr (ehdr=0x7fffffffd390, elf=0x882b30) at dwarf_getcfi_elf.c:283
        #3  dwarf_getcfi_elf (elf=0x882b30) at dwarf_getcfi_elf.c:309
        #4  0x00000000004d5bac in debuginfo__find_probes (pf=0x7fffffffd4f0,
            dbg=Unhandled dwarf expression opcode 0xfa) at util/probe-finder.c:993
        #5  0x00000000004d634a in debuginfo__find_trace_events (dbg=0x880840,
            pev=<optimized out>, tevs=0x880f88, max_tevs=<optimized out>) at
            util/probe-finder.c:1200
        #6  0x00000000004aed6b in try_to_find_probe_trace_events (target=0x881b20
            "/lib64/libpthread-2.14.90.so",
            max_tevs=128, tevs=0x880f88, pev=0x859b30) at util/probe-event.c:482
        #7  convert_to_probe_trace_events (target=0x881b20
            "/lib64/libpthread-2.14.90.so", max_tevs=128, tevs=0x880f88,
            pev=0x859b30) at util/probe-event.c:2356
        #8  add_perf_probe_events (pevs=<optimized out>, npevs=1, max_tevs=128,
            target=0x881b20 "/lib64/libpthread-2.14.90.so", force_add=false) at
            util/probe-event.c:2391
        #9  0x000000000044014f in __cmd_probe (argc=<optimized out>,
            argv=0x7fffffffe2f0, prefix=Unhandled dwarf expression opcode 0xfa) at
            at builtin-probe.c:488
        #10 0x0000000000440313 in cmd_probe (argc=5, argv=0x7fffffffe2f0,
            prefix=<optimized out>) at builtin-probe.c:506
        #11 0x000000000041d133 in run_builtin (p=0x805680, argc=5,
            argv=0x7fffffffe2f0) at perf.c:341
        #12 0x000000000041c8b2 in handle_internal_command (argv=<optimized out>,
            argc=<optimized out>) at perf.c:400
        #13 run_argv (argv=<optimized out>, argcp=<optimized out>) at perf.c:444
        #14 main (argc=5, argv=0x7fffffffe2f0) at perf.c:559
      
      And I found a related commit (5704c8c4fa71 "getcfi_scn_eh_frame: Don't
      crash and burn when .eh_frame bits aren't there.") in elfutils that can
      lead to a unexpected crash like this.  To safely use the function, it
      needs to check the .eh_frame section is a PROGBITS type.
      Reported-by: NDavid Ahern <dsahern@gmail.com>
      Tested-by: NDavid Ahern <dsahern@gmail.com>
      Signed-off-by: NNamhyung Kim <namhyung@kernel.org>
      Acked-by: NMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
      Cc: David Ahern <dsahern@gmail.com>
      Cc: Mark Wielaard <mjw@redhat.com>
      Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
      Link: http://lkml.kernel.org/r/20141230090533.GH6081@sejongSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      4093325f
  19. 18 9月, 2014 1 次提交
  20. 15 8月, 2014 1 次提交
  21. 17 7月, 2014 1 次提交
  22. 10 6月, 2014 1 次提交
    • M
      perf probe: Improve an error message of perf probe --vars mode · 69e96eaa
      Masami Hiramatsu 提交于
      Fix an error message when failed to find given address in --vars
      mode.
      
      Without this fix, perf probe -V doesn't show the final "Error"
      message if it fails to find given source line. Moreover, it
      tells it fails to find "variables" instead of the source line.
        -----
        # perf probe -V foo@bar
        Failed to find variables at foo@bar (0)
        -----
      The result also shows mysterious error code. Actually the error
      returns 0 or -ENOENT means that it just fails to find the address
      of given source line. (0 means there is no matching address,
      and -ENOENT means there is an entry(DIE) but it has no instance,
      e.g. an empty inlined function)
      
      This fixes it to show what happened and the final error message
      as below.
        -----
        # perf probe -V foo@bar
        Failed to find the address of foo@bar
          Error: Failed to show vars.
        -----
      Signed-off-by: NMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
      Cc: Ingo Molnar <mingo@kernel.org>
      Cc: Jiri Olsa <jolsa@redhat.com>
      Cc: Namhyung Kim <namhyung@kernel.org>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
      Link: http://lkml.kernel.org/r/20140606071359.6788.84716.stgit@kbuild-fedora.novalocalSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      69e96eaa
  23. 09 6月, 2014 1 次提交
  24. 04 6月, 2014 1 次提交
  25. 14 4月, 2014 3 次提交
  26. 18 2月, 2014 3 次提交
  27. 28 12月, 2013 1 次提交