From 3f4460a28fb2f73df6c32c3a305797abc01c0f9c Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Thu, 11 Aug 2011 20:03:18 +0900 Subject: perf probe: Filter out redundant inline-instances 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 high_pc (addr) .text+0x000000000000248b 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 high_pc (addr) .text+0x0000000000002480 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 @ struct timer_list* timer @ (No matched variables) So, this filters out those redundant instances based on call-site and decl-site information. Cc: Frederic Weisbecker Cc: Ingo Molnar Cc: Paul Mackerras Cc: Pekka Enberg Cc: Peter Zijlstra Cc: yrl.pp-manager.tt@hitachi.com Link: http://lkml.kernel.org/r/20110811110317.19900.59525.stgit@fedora15 Signed-off-by: Masami Hiramatsu Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/dwarf-aux.c | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) (limited to 'tools/perf') diff --git a/tools/perf/util/dwarf-aux.c b/tools/perf/util/dwarf-aux.c index d0f4048b634..ee51e9b4dc0 100644 --- a/tools/perf/util/dwarf-aux.c +++ b/tools/perf/util/dwarf-aux.c @@ -307,6 +307,17 @@ static int die_get_call_fileno(Dwarf_Die *in_die) return -ENOENT; } +/* Get the declared file index number in CU DIE */ +static int die_get_decl_fileno(Dwarf_Die *pdie) +{ + Dwarf_Sword idx; + + if (die_get_attr_sdata(pdie, DW_AT_decl_file, &idx) == 0) + return (int)idx; + else + return -ENOENT; +} + /** * die_get_call_file - Get callsite file name of inlined function instance * @in_die: a DIE of an inlined function instance @@ -467,6 +478,7 @@ static int __die_walk_instances_cb(Dwarf_Die *inst, void *data) Dwarf_Die origin_mem; Dwarf_Attribute *attr; Dwarf_Die *origin; + int tmp; attr = dwarf_attr(inst, DW_AT_abstract_origin, &attr_mem); if (attr == NULL) @@ -476,6 +488,16 @@ static int __die_walk_instances_cb(Dwarf_Die *inst, void *data) if (origin == NULL || origin->addr != iwp->addr) return DIE_FIND_CB_CONTINUE; + /* Ignore redundant instances */ + if (dwarf_tag(inst) == DW_TAG_inlined_subroutine) { + dwarf_decl_line(origin, &tmp); + if (die_get_call_lineno(inst) == tmp) { + tmp = die_get_decl_fileno(origin); + if (die_get_call_fileno(inst) == tmp) + return DIE_FIND_CB_CONTINUE; + } + } + iwp->retval = iwp->callback(inst, iwp->data); return (iwp->retval) ? DIE_FIND_CB_END : DIE_FIND_CB_CONTINUE; -- cgit v1.2.3