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2013-10-04perf probe: Fix to find line information for probe listMasami Hiramatsu
Fix to find the correct (as much as possible) line information for listing probes. Without this fix, perf probe --list action will show incorrect line information as below; probe:getname_flags (on getname_flags@ksrc/linux-3/fs/namei.c) probe:getname_flags_1 (on getname:-89@x86/include/asm/current.h) probe:getname_flags_2 (on user_path_at_empty:-2054@x86/include/asm/current.h) The minus line number is obviously wrong, and current.h is not related to the probe point. Deeper investigation discovered that there were 2 issues related to this bug, and minor typos too. The 1st issue is the rack of considering about nested inlined functions, which causes the wrong (relative) line number. The 2nd issue is that the dwarf line info is not correct at those points. It points 14th line of current.h. Since it seems that the line info includes somewhat unreliable information, this fixes perf to try to find correct line information from both of debuginfo and line info as below. 1) Probe address is the entry of a function instance In this case, the line is set as the function declared line. 2) Probe address is the entry of an expanded inline function block In this case, the line is set as the function call-site line. This means that the line number is relative from the entry line of caller function (which can be an inlined function if nested) 3) Probe address is inside a function instance or an expanded inline function block In this case, perf probe queries the line number from lineinfo and verify the function declared file is same as the file name queried from lineinfo. If the file name is different, it is a failure case. The probe address is shown as symbol+offset. 4) Probe address is not in the any function instance This is a failure case, the probe address is shown as symbol+offset. With this fix, perf probe -l shows correct probe lines as below; probe:getname_flags (on getname_flags@ksrc/linux-3/fs/namei.c) probe:getname_flags_1 (on getname:2@ksrc/linux-3/fs/namei.c) probe:getname_flags_2 (on user_path_at_empty:4@ksrc/linux-3/fs/namei.c) Changes at v2: - Fix typos in the function comments. (Thanks to Namhyung Kim) - Use die_find_top_inlinefunc instead of die_find_inlinefunc_next. Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Ingo Molnar <mingo@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/20130930092144.1693.11058.stgit@udc4-manage.rcp.hitachi.co.jp Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2013-09-19perf probe: Fix finder to find lines of given functionMasami Hiramatsu
The commit ba28c59bc9ed8fb7b9a753cd88ee54a2c4f6265b fixed a declaration entry bug in probe_point_search_cb(). There are same bugs in line finder and call_probe_finder(). This introduces a new dwarf utility function to determine given DIE is a function definition, not declaration. Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Prashanth Nageshappa <prashanth@linux.vnet.ibm.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: yrl.pp-manager.tt@hitachi.com Link: http://lkml.kernel.org/r/20120423032435.8737.80064.stgit@localhost.localdomain Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2012-09-27perf probe: Print an enum type variable in "enum variable-name" format when ↵Hyeoncheol Lee
showing accessible variables When showing accessible variables, an enum type variable was printed in "variable-name" format. Change this format into "enum variable-name". Signed-off-by: Hyeoncheol Lee <hyc.lee@gmail.com> Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Link: http://lkml.kernel.org/r/1348713399-4541-1-git-send-email-hyc.lee@gmail.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2011-08-12perf probe: Filter out redundant inline-instancesMasami Hiramatsu
With gcc4.6, some instances of concrete inlined function looks redundant and broken, because it appears inside of a concrete instance and its call_file and call_line are same as the original abstruct's decl_file and decl_line respectively. e.g. [ d1aa] subprogram external (flag) Yes name (strp) "add_timer" decl_file (data1) 2 ;here is original decl_line (data2) 847 ;line and file prototyped (flag) Yes inline (data1) inlined (1) sibling (ref4) [ d1c6] ... [ 11d84] subprogram abstract_origin (ref4) [ d1aa] ; concrete instance low_pc (addr) .text+0x000000000000246f <add_timer> high_pc (addr) .text+0x000000000000248b <mod_timer_pending> frame_base (block1) [ 0] call_frame_cfa sibling (ref4) [ 11dd9] [ 11d9f] formal_parameter abstract_origin (ref4) [ d1b9] location (data4) location list [ 701b] [ 11da8] inlined_subroutine abstract_origin (ref4) [ d1aa] ; redundant instance low_pc (addr) .text+0x000000000000247e <add_timer+0xf> high_pc (addr) .text+0x0000000000002480 <add_timer+0x11> call_file (data1) 2 ; call line and file call_line (data2) 847 ; are same as above Those redundant instances leads unwilling results; e.g. find probe points inside of functions even if we specify a function entry as below; $ perf probe -V add_timer Available variables at add_timer @<add_timer+0> struct timer_list* timer @<add_timer+15> (No matched variables) So, this filters out those redundant instances based on call-site and decl-site information. Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Paul Mackerras <paulus@samba.org> Cc: Pekka Enberg <penberg@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: yrl.pp-manager.tt@hitachi.com Link: http://lkml.kernel.org/r/20110811110317.19900.59525.stgit@fedora15 Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2011-08-12perf probe: Search concrete out-of-line instancesMasami Hiramatsu
gcc 4.6 generates a concrete out-of-line instance when there is a function which is implicitly inlined somewhere but also has its own instance. The concrete out-of-line instance means that it has an abstract origin of the function which is referred by not only inlined-subroutines but also a concrete subprogram. Since current dwarf_func_inline_instances() can find only instances of inlined-subroutines, this introduces new die_walk_instances() to find both of subprogram and inlined-subroutines. e.g. without this, Available variables at sched_group_rt_period @<cpu_rt_period_read_uint+9> struct task_group* tg perf probe failed to find actual subprogram instance of sched_group_rt_period(). With this, Available variables at sched_group_rt_period @<cpu_rt_period_read_uint+9> struct task_group* tg @<sched_group_rt_period+0> struct task_group* tg Now it found the sched_group_rt_period() itself. Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Paul Mackerras <paulus@samba.org> Cc: Pekka Enberg <penberg@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: yrl.pp-manager.tt@hitachi.com Link: http://lkml.kernel.org/r/20110811110311.19900.63997.stgit@fedora15 Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2011-08-12perf probe: Fix to search local variables in appropriate scopeMasami Hiramatsu
Fix perf probe to search local variables in appropriate local inlined function scope. For example, pre_schedule() has only 2 local variables, as below; $ perf probe -L pre_schedule <pre_schedule@/home/mhiramat/ksrc/linux-2.6/kernel/sched.c:0> 0 static inline void pre_schedule(struct rq *rq, struct task_struct *prev) { 2 if (prev->sched_class->pre_schedule) 3 prev->sched_class->pre_schedule(rq, prev); } However, current perf probe shows 4 local variables on pre_schedule(), because it searches variables in the caller(schedule()) scope. $ perf probe -V pre_schedule Available variables at pre_schedule @<schedule+445> int cpu long unsigned int* switch_count struct rq* rq struct task_struct* prev This patch fixes this issue by searching variables in the local scope of the instance of inlined function. Here is the result. $ perf probe -V pre_schedule Available variables at pre_schedule @<schedule+445> struct rq* rq struct task_struct* prev Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Paul Mackerras <paulus@samba.org> Cc: Pekka Enberg <penberg@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: yrl.pp-manager.tt@hitachi.com Link: http://lkml.kernel.org/r/20110811110259.19900.85664.stgit@fedora15 Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2011-08-12perf probe: Fix to search nested inlined functions in CUMasami Hiramatsu
Fix perf probe to walk through the lines of all nested inlined function call sites and declared lines when a whole CU is passed to the line walker. The die_walk_lines() can have two different type of DIEs, subprogram (or inlined-subroutine) DIE and CU DIE. If a caller passes a subprogram DIE, this means that the walker walk on lines of given subprogram. In this case, it just needs to search on direct children of DIE tree for finding call-site information of inlined function which directly called from given subprogram. On the other hand, if a caller passes a CU DIE to the walker, this means that the walker have to walk on all lines in the source files included in given CU DIE. In this case, it has to search whole DIE trees of all subprograms to find the call-site information of all nested inlined functions. Without this patch: $ perf probe --line kernel/cpu.c:151-157 </home/mhiramat/ksrc/linux-2.6/kernel/cpu.c:151> static int cpu_notify(unsigned long val, void *v) { 154 return __cpu_notify(val, v, -1, NULL); } With this: $ perf probe --line kernel/cpu.c:151-157 </home/mhiramat/ksrc/linux-2.6/kernel/cpu.c:151> 152 static int cpu_notify(unsigned long val, void *v) { 154 return __cpu_notify(val, v, -1, NULL); } As you can see, --line option with source line range shows the declared lines as probe-able. Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Paul Mackerras <paulus@samba.org> Cc: Pekka Enberg <penberg@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: yrl.pp-manager.tt@hitachi.com Link: http://lkml.kernel.org/r/20110811110241.19900.34994.stgit@fedora15 Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2011-08-12perf probe: Fix line walker to check CU correctlyMasami Hiramatsu
Fix line walker to check whether a given DIE is CU or not. Actually this function accepts CU, subprogram and inlined_subroutine DIEs. Without this fix, perf probe always fails to analyze lines on inlined functions; $ perf probe -L pre_schedule Debuginfo analysis failed. (-2) Error: Failed to show lines. (-2) This fixes that bug, as below. $ perf probe -L pre_schedule <pre_schedule@/home/mhiramat/ksrc/linux-2.6/kernel/sched.c:0> 0 static inline void pre_schedule(struct rq *rq, struct task_struct *prev { 2 if (prev->sched_class->pre_schedule) 3 prev->sched_class->pre_schedule(rq, prev); } /* rq->lock is NOT held, but preemption is disabled */ Changes from v1: - Update against current tip tree.(Fix dwarf-aux.c) Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Masami Hiramatsu <masami.hiramatsu@gmail.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Pekka Enberg <penberg@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: yrl.pp-manager.tt@hitachi.com Link: http://lkml.kernel.org/r/20110811110235.19900.20614.stgit@fedora15 Signed-off-by: Masami Hiramatsu <masami.hiramatsu@gmail.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2011-07-15perf-probe: Move dwarf library routines to dwarf-aux.{c, h}Masami Hiramatsu
Move dwarf library related routines to dwarf-aux.{c,h}. This includes several minor changes. - Add simple documents for each API. - Rename die_find_real_subprogram() to die_find_realfunc() - Rename line_walk_handler_t to line_walk_callback_t. - Minor cleanups. Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net> Link: http://lkml.kernel.org/r/20110627072727.6528.57647.stgit@fedora15 Signed-off-by: Steven Rostedt <rostedt@goodmis.org>