From b0ef07324310d66f660a311d4a8d669eda74f801 Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Tue, 27 Oct 2009 16:43:19 -0400 Subject: perf/probes: Support function entry relative line number Add function-entry relative line number specifying support to perf-probe. This allows users to define probes by line number from entry of the function. e.g. perf probe schedule:16 Signed-off-by: Masami Hiramatsu Cc: Steven Rostedt Cc: Jim Keniston Cc: Ananth N Mavinakayanahalli Cc: Christoph Hellwig Cc: Frank Ch. Eigler Cc: Frederic Weisbecker Cc: Jason Baron Cc: K.Prasad Cc: Peter Zijlstra Cc: Srikar Dronamraju LKML-Reference: <20091027204319.30545.30678.stgit@harusame> Signed-off-by: Ingo Molnar --- tools/perf/util/probe-finder.c | 79 ++++++++++++++++++++++++++++++++---------- tools/perf/util/probe-finder.h | 2 ++ 2 files changed, 63 insertions(+), 18 deletions(-) (limited to 'tools/perf/util') diff --git a/tools/perf/util/probe-finder.c b/tools/perf/util/probe-finder.c index 6d3bac9f9473..db96186e02a8 100644 --- a/tools/perf/util/probe-finder.c +++ b/tools/perf/util/probe-finder.c @@ -114,7 +114,7 @@ static int strtailcmp(const char *s1, const char *s2) } /* Find the fileno of the target file. */ -static Dwarf_Unsigned die_get_fileno(Dwarf_Die cu_die, const char *fname) +static Dwarf_Unsigned cu_find_fileno(Dwarf_Die cu_die, const char *fname) { Dwarf_Signed cnt, i; Dwarf_Unsigned found = 0; @@ -335,6 +335,36 @@ static int attr_get_locdesc(Dwarf_Attribute attr, Dwarf_Locdesc *desc, return ret; } +/* Get decl_file attribute value (file number) */ +static Dwarf_Unsigned die_get_decl_file(Dwarf_Die sp_die) +{ + Dwarf_Attribute attr; + Dwarf_Unsigned fno; + int ret; + + ret = dwarf_attr(sp_die, DW_AT_decl_file, &attr, &__dw_error); + DIE_IF(ret != DW_DLV_OK); + dwarf_formudata(attr, &fno, &__dw_error); + DIE_IF(ret != DW_DLV_OK); + dwarf_dealloc(__dw_debug, attr, DW_DLA_ATTR); + return fno; +} + +/* Get decl_line attribute value (line number) */ +static Dwarf_Unsigned die_get_decl_line(Dwarf_Die sp_die) +{ + Dwarf_Attribute attr; + Dwarf_Unsigned lno; + int ret; + + ret = dwarf_attr(sp_die, DW_AT_decl_line, &attr, &__dw_error); + DIE_IF(ret != DW_DLV_OK); + dwarf_formudata(attr, &lno, &__dw_error); + DIE_IF(ret != DW_DLV_OK); + dwarf_dealloc(__dw_debug, attr, DW_DLA_ATTR); + return lno; +} + /* * Probe finder related functions */ @@ -501,6 +531,7 @@ static void show_probepoint(Dwarf_Die sp_die, Dwarf_Signed offs, DIE_IF(ret < 0); DIE_IF(ret >= MAX_PROBE_BUFFER); len = ret; + pr_debug("Probe point found: %s\n", tmp); /* Find each argument */ get_current_frame_base(sp_die, pf); @@ -536,17 +567,16 @@ static int probeaddr_callback(struct die_link *dlink, void *data) } /* Find probe point from its line number */ -static void find_by_line(Dwarf_Die cu_die, struct probe_finder *pf) +static void find_by_line(struct probe_finder *pf) { - struct probe_point *pp = pf->pp; - Dwarf_Signed cnt, i; + Dwarf_Signed cnt, i, clm; Dwarf_Line *lines; Dwarf_Unsigned lineno = 0; Dwarf_Addr addr; Dwarf_Unsigned fno; int ret; - ret = dwarf_srclines(cu_die, &lines, &cnt, &__dw_error); + ret = dwarf_srclines(pf->cu_die, &lines, &cnt, &__dw_error); DIE_IF(ret != DW_DLV_OK); for (i = 0; i < cnt; i++) { @@ -557,15 +587,20 @@ static void find_by_line(Dwarf_Die cu_die, struct probe_finder *pf) ret = dwarf_lineno(lines[i], &lineno, &__dw_error); DIE_IF(ret != DW_DLV_OK); - if (lineno != (Dwarf_Unsigned)pp->line) + if (lineno != pf->lno) continue; + ret = dwarf_lineoff(lines[i], &clm, &__dw_error); + DIE_IF(ret != DW_DLV_OK); + ret = dwarf_lineaddr(lines[i], &addr, &__dw_error); DIE_IF(ret != DW_DLV_OK); - pr_debug("Probe point found: 0x%llx\n", addr); + pr_debug("Probe line found: line[%d]:%u,%d addr:0x%llx\n", + (int)i, (unsigned)lineno, (int)clm, addr); pf->addr = addr; /* Search a real subprogram including this line, */ - ret = search_die_from_children(cu_die, probeaddr_callback, pf); + ret = search_die_from_children(pf->cu_die, + probeaddr_callback, pf); if (ret == 0) die("Probe point is not found in subprograms.\n"); /* Continuing, because target line might be inlined. */ @@ -587,6 +622,13 @@ static int probefunc_callback(struct die_link *dlink, void *data) DIE_IF(ret == DW_DLV_ERROR); if (tag == DW_TAG_subprogram) { if (die_compare_name(dlink->die, pp->function) == 0) { + if (pp->line) { /* Function relative line */ + pf->fno = die_get_decl_file(dlink->die); + pf->lno = die_get_decl_line(dlink->die) + + pp->line; + find_by_line(pf); + return 1; + } if (die_inlined_subprogram(dlink->die)) { /* Inlined function, save it. */ ret = dwarf_die_CU_offset(dlink->die, @@ -631,9 +673,9 @@ found: return 0; } -static void find_by_func(Dwarf_Die cu_die, struct probe_finder *pf) +static void find_by_func(struct probe_finder *pf) { - search_die_from_children(cu_die, probefunc_callback, pf); + search_die_from_children(pf->cu_die, probefunc_callback, pf); } /* Find a probe point */ @@ -641,7 +683,6 @@ int find_probepoint(int fd, struct probe_point *pp) { Dwarf_Half addr_size = 0; Dwarf_Unsigned next_cuh = 0; - Dwarf_Die cu_die = 0; int cu_number = 0, ret; struct probe_finder pf = {.pp = pp}; @@ -659,25 +700,27 @@ int find_probepoint(int fd, struct probe_point *pp) break; /* Get the DIE(Debugging Information Entry) of this CU */ - ret = dwarf_siblingof(__dw_debug, 0, &cu_die, &__dw_error); + ret = dwarf_siblingof(__dw_debug, 0, &pf.cu_die, &__dw_error); DIE_IF(ret != DW_DLV_OK); /* Check if target file is included. */ if (pp->file) - pf.fno = die_get_fileno(cu_die, pp->file); + pf.fno = cu_find_fileno(pf.cu_die, pp->file); if (!pp->file || pf.fno) { /* Save CU base address (for frame_base) */ - ret = dwarf_lowpc(cu_die, &pf.cu_base, &__dw_error); + ret = dwarf_lowpc(pf.cu_die, &pf.cu_base, &__dw_error); DIE_IF(ret == DW_DLV_ERROR); if (ret == DW_DLV_NO_ENTRY) pf.cu_base = 0; - if (pp->line) - find_by_line(cu_die, &pf); if (pp->function) - find_by_func(cu_die, &pf); + find_by_func(&pf); + else { + pf.lno = pp->line; + find_by_line(&pf); + } } - dwarf_dealloc(__dw_debug, cu_die, DW_DLA_DIE); + dwarf_dealloc(__dw_debug, pf.cu_die, DW_DLA_DIE); } ret = dwarf_finish(__dw_debug, &__dw_error); DIE_IF(ret != DW_DLV_OK); diff --git a/tools/perf/util/probe-finder.h b/tools/perf/util/probe-finder.h index 240d6cb3cc2e..bdebca6697d2 100644 --- a/tools/perf/util/probe-finder.h +++ b/tools/perf/util/probe-finder.h @@ -41,7 +41,9 @@ struct probe_finder { /* For function searching */ Dwarf_Addr addr; /* Address */ Dwarf_Unsigned fno; /* File number */ + Dwarf_Unsigned lno; /* Line number */ Dwarf_Off inl_offs; /* Inline offset */ + Dwarf_Die cu_die; /* Current CU */ /* For variable searching */ Dwarf_Addr cu_base; /* Current CU base address */ -- cgit v1.2.3