From 7d21635ac5c78abe162fb3f56b37c30bcbfa019f Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Wed, 30 Mar 2011 18:25:41 +0900 Subject: perf probe: Fix to ensure function declared file Fix to ensure function declared file matches given file name. This fixes a potential bug. As I've commented on Lin Ming's fastpath enhancement, decl_file should be checked on each probe point if user gives a probe point as func@file. Cc: 2nddept-manager@sdl.hitachi.co.jp Cc: Frederic Weisbecker Cc: Ingo Molnar Cc: Lin Ming Cc: Peter Zijlstra LKML-Reference: <20110330092541.2132.3584.stgit@ltc236.sdl.hitachi.co.jp> Signed-off-by: Masami Hiramatsu Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/probe-finder.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/tools/perf/util/probe-finder.c b/tools/perf/util/probe-finder.c index 194f9e2..3bcd140 100644 --- a/tools/perf/util/probe-finder.c +++ b/tools/perf/util/probe-finder.c @@ -1395,6 +1395,10 @@ static int probe_point_search_cb(Dwarf_Die *sp_die, void *data) !die_compare_name(sp_die, pp->function)) return DWARF_CB_OK; + /* Check declared file */ + if (pp->file && strtailcmp(pp->file, dwarf_decl_file(sp_die))) + return DWARF_CB_OK; + pf->fname = dwarf_decl_file(sp_die); if (pp->line) { /* Function relative line */ dwarf_decl_line(sp_die, &pf->lno); @@ -1840,6 +1844,10 @@ static int line_range_search_cb(Dwarf_Die *sp_die, void *data) struct line_finder *lf = param->data; struct line_range *lr = lf->lr; + /* Check declared file */ + if (lr->file && strtailcmp(lr->file, dwarf_decl_file(sp_die))) + return DWARF_CB_OK; + if (dwarf_tag(sp_die) == DW_TAG_subprogram && die_compare_name(sp_die, lr->function)) { lf->fname = dwarf_decl_file(sp_die); -- cgit v1.1 From f0c4801a17cb1a762bed39a6a9d5e5be33d8a340 Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Wed, 30 Mar 2011 18:25:47 +0900 Subject: perf probe: Fix to remove redundant close Since dwfl_end() closes given fd with dwfl, caller doesn't need to close its fd when finishing process. Cc: 2nddept-manager@sdl.hitachi.co.jp Cc: Frederic Weisbecker Cc: Ingo Molnar Cc: Lin Ming Cc: Peter Zijlstra LKML-Reference: <20110330092547.2132.93728.stgit@ltc236.sdl.hitachi.co.jp> Signed-off-by: Masami Hiramatsu Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/probe-event.c | 3 --- tools/perf/util/probe-finder.c | 2 ++ 2 files changed, 2 insertions(+), 3 deletions(-) diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c index 5ddee66..a372d74 100644 --- a/tools/perf/util/probe-event.c +++ b/tools/perf/util/probe-event.c @@ -234,7 +234,6 @@ static int try_to_find_probe_trace_events(struct perf_probe_event *pev, /* Searching trace events corresponding to probe event */ ntevs = find_probe_trace_events(fd, pev, tevs, max_tevs); - close(fd); if (ntevs > 0) { /* Succeeded to find trace events */ pr_debug("find %d probe_trace_events.\n", ntevs); @@ -388,7 +387,6 @@ int show_line_range(struct line_range *lr, const char *module) } ret = find_line_range(fd, lr); - close(fd); if (ret == 0) { pr_warning("Specified source line is not found.\n"); return -ENOENT; @@ -524,7 +522,6 @@ int show_available_vars(struct perf_probe_event *pevs, int npevs, ret = show_available_vars_at(fd, &pevs[i], max_vls, _filter, externs); - close(fd); return ret; } diff --git a/tools/perf/util/probe-finder.c b/tools/perf/util/probe-finder.c index 3bcd140..5473f11 100644 --- a/tools/perf/util/probe-finder.c +++ b/tools/perf/util/probe-finder.c @@ -1455,6 +1455,7 @@ static int find_probes(int fd, struct probe_finder *pf) if (!dbg) { pr_warning("No debug information found in the vmlinux - " "please rebuild with CONFIG_DEBUG_INFO=y.\n"); + close(fd); /* Without dwfl_end(), fd isn't closed. */ return -EBADF; } @@ -1900,6 +1901,7 @@ int find_line_range(int fd, struct line_range *lr) if (!dbg) { pr_warning("No debug information found in the vmlinux - " "please rebuild with CONFIG_DEBUG_INFO=y.\n"); + close(fd); /* Without dwfl_end(), fd isn't closed. */ return -EBADF; } -- cgit v1.1 From cc446446ff48e82c157dc8c937a3490f2a2ce535 Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Wed, 30 Mar 2011 18:25:53 +0900 Subject: perf probe: Fix multiple --vars options behavior Fix a bug that perf-probe fails to initialize libdwfl and shows incorrect error when user gives multiple --vars options. Cc: 2nddept-manager@sdl.hitachi.co.jp Cc: Frederic Weisbecker Cc: Ingo Molnar Cc: Lin Ming Cc: Peter Zijlstra LKML-Reference: <20110330092553.2132.42691.stgit@ltc236.sdl.hitachi.co.jp> Signed-off-by: Masami Hiramatsu Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/probe-event.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c index a372d74..f022316 100644 --- a/tools/perf/util/probe-event.c +++ b/tools/perf/util/probe-event.c @@ -510,18 +510,18 @@ int show_available_vars(struct perf_probe_event *pevs, int npevs, if (ret < 0) return ret; - fd = open_vmlinux(module); - if (fd < 0) { - pr_warning("Failed to open debug information file.\n"); - return fd; - } - setup_pager(); - for (i = 0; i < npevs && ret >= 0; i++) + for (i = 0; i < npevs && ret >= 0; i++) { + fd = open_vmlinux(module); + if (fd < 0) { + pr_warning("Failed to open debug information file.\n"); + ret = fd; + break; + } ret = show_available_vars_at(fd, &pevs[i], max_vls, _filter, externs); - + } return ret; } -- cgit v1.1 From 1d878083c253fb2e2471b39e825447aca66fc05c Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Wed, 30 Mar 2011 18:25:59 +0900 Subject: perf probe: Fix to find recursively inlined function Fix die_find_inlinefunc() to return correct innermost inlined function at given address. Without this fix, it returns the outermost inlined function. Cc: 2nddept-manager@sdl.hitachi.co.jp Cc: Frederic Weisbecker Cc: Ingo Molnar Cc: Lin Ming Cc: Peter Zijlstra LKML-Reference: <20110330092559.2132.78634.stgit@ltc236.sdl.hitachi.co.jp> Signed-off-by: Masami Hiramatsu Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/probe-finder.c | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-) diff --git a/tools/perf/util/probe-finder.c b/tools/perf/util/probe-finder.c index 5473f11..689ab46 100644 --- a/tools/perf/util/probe-finder.c +++ b/tools/perf/util/probe-finder.c @@ -497,7 +497,20 @@ static int __die_find_inline_cb(Dwarf_Die *die_mem, void *data) static Dwarf_Die *die_find_inlinefunc(Dwarf_Die *sp_die, Dwarf_Addr addr, Dwarf_Die *die_mem) { - return die_find_child(sp_die, __die_find_inline_cb, &addr, die_mem); + Dwarf_Die tmp_die; + + sp_die = die_find_child(sp_die, __die_find_inline_cb, &addr, &tmp_die); + if (!sp_die) + return NULL; + + /* Inlined function could be recursive. Trace it until fail */ + while (sp_die) { + memcpy(die_mem, sp_die, sizeof(Dwarf_Die)); + sp_die = die_find_child(sp_die, __die_find_inline_cb, &addr, + &tmp_die); + } + + return die_mem; } /* Walker on lines (Note: line number will not be sorted) */ -- cgit v1.1 From 1d46ea2a6a405196435ffcc2adb3ef5402a30b3a Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Wed, 30 Mar 2011 18:26:05 +0900 Subject: perf probe: Fix listing incorrect line number with inline function Fix a bug showing incorrect line number when a probe is put on the head of an inline function. This patch updates find_perf_probe_point() and introduces new rules to get correct line number. - If debuginfo doesn't have a correct file name, we shouldn't return line number too, because, without file name, line number is meaningless. - If the address is in a function, it stores the function name and the offset from the function entry. - If the address is on a line, it tries to get the relative line number from the function entry line, except for the address is same as the entry address of the function (in this case, the relative line number should be 0). - If the address is in an inline function entry (call-site), it uses the inline function call line number as the line on which the address is. - If the address is in an inline function body, it stores the inline function name and offset from the inline function call site instead of the (non-inlined) function. Cc: 2nddept-manager@sdl.hitachi.co.jp Cc: Frederic Weisbecker Cc: Ingo Molnar Cc: Lin Ming Cc: Peter Zijlstra LKML-Reference: <20110330092605.2132.11629.stgit@ltc236.sdl.hitachi.co.jp> Signed-off-by: Masami Hiramatsu Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/probe-finder.c | 134 +++++++++++++++++++++++++---------------- 1 file changed, 81 insertions(+), 53 deletions(-) diff --git a/tools/perf/util/probe-finder.c b/tools/perf/util/probe-finder.c index 689ab46..b7c85ce 100644 --- a/tools/perf/util/probe-finder.c +++ b/tools/perf/util/probe-finder.c @@ -273,6 +273,25 @@ static const char *cu_get_comp_dir(Dwarf_Die *cu_die) return dwarf_formstring(&attr); } +/* Get a line number and file name for given address */ +static int cu_find_lineinfo(Dwarf_Die *cudie, unsigned long addr, + const char **fname, int *lineno) +{ + Dwarf_Line *line; + Dwarf_Addr laddr; + + line = dwarf_getsrc_die(cudie, (Dwarf_Addr)addr); + if (line && dwarf_lineaddr(line, &laddr) == 0 && + addr == (unsigned long)laddr && dwarf_lineno(line, lineno) == 0) { + *fname = dwarf_linesrc(line, NULL, NULL); + if (!*fname) + /* line number is useless without filename */ + *lineno = 0; + } + + return *lineno ?: -ENOENT; +} + /* Compare diename and tname */ static bool die_compare_name(Dwarf_Die *dw_die, const char *tname) { @@ -1704,11 +1723,9 @@ int find_perf_probe_point(unsigned long addr, struct perf_probe_point *ppt) Dwarf_Die cudie, spdie, indie; Dwarf *dbg = NULL; Dwfl *dwfl = NULL; - Dwarf_Line *line; - Dwarf_Addr laddr, eaddr, bias = 0; - const char *tmp; - int lineno, ret = 0; - bool found = false; + Dwarf_Addr _addr, baseaddr, bias = 0; + const char *fname = NULL, *func = NULL, *tmp; + int baseline = 0, lineno = 0, ret = 0; /* Open the live linux kernel */ dbg = dwfl_init_live_kernel_dwarf(addr, &dwfl, &bias); @@ -1729,68 +1746,79 @@ int find_perf_probe_point(unsigned long addr, struct perf_probe_point *ppt) goto end; } - /* Find a corresponding line */ - line = dwarf_getsrc_die(&cudie, (Dwarf_Addr)addr); - if (line) { - if (dwarf_lineaddr(line, &laddr) == 0 && - (Dwarf_Addr)addr == laddr && - dwarf_lineno(line, &lineno) == 0) { - tmp = dwarf_linesrc(line, NULL, NULL); - if (tmp) { - ppt->line = lineno; - ppt->file = strdup(tmp); - if (ppt->file == NULL) { - ret = -ENOMEM; - goto end; - } - found = true; - } - } - } + /* Find a corresponding line (filename and lineno) */ + cu_find_lineinfo(&cudie, addr, &fname, &lineno); + /* Don't care whether it failed or not */ - /* Find a corresponding function */ + /* Find a corresponding function (name, baseline and baseaddr) */ if (die_find_real_subprogram(&cudie, (Dwarf_Addr)addr, &spdie)) { + /* Get function entry information */ tmp = dwarf_diename(&spdie); - if (!tmp || dwarf_entrypc(&spdie, &eaddr) != 0) - goto end; - - if (ppt->line) { - if (die_find_inlinefunc(&spdie, (Dwarf_Addr)addr, - &indie)) { - /* addr in an inline function */ + if (!tmp || + dwarf_entrypc(&spdie, &baseaddr) != 0 || + dwarf_decl_line(&spdie, &baseline) != 0) + goto post; + func = tmp; + + if (addr == (unsigned long)baseaddr) + /* Function entry - Relative line number is 0 */ + lineno = baseline; + else if (die_find_inlinefunc(&spdie, (Dwarf_Addr)addr, + &indie)) { + if (dwarf_entrypc(&indie, &_addr) == 0 && + _addr == addr) + /* + * addr is at an inline function entry. + * In this case, lineno should be the call-site + * line number. + */ + lineno = die_get_call_lineno(&indie); + else { + /* + * addr is in an inline function body. + * Since lineno points one of the lines + * of the inline function, baseline should + * be the entry line of the inline function. + */ tmp = dwarf_diename(&indie); - if (!tmp) - goto end; - ret = dwarf_decl_line(&indie, &lineno); - } else { - if (eaddr == addr) { /* Function entry */ - lineno = ppt->line; - ret = 0; - } else - ret = dwarf_decl_line(&spdie, &lineno); - } - if (ret == 0) { - /* Make a relative line number */ - ppt->line -= lineno; - goto found; + if (tmp && + dwarf_decl_line(&spdie, &baseline) == 0) + func = tmp; } } - /* We don't have a line number, let's use offset */ - ppt->offset = addr - (unsigned long)eaddr; -found: - ppt->function = strdup(tmp); + } + +post: + /* Make a relative line number or an offset */ + if (lineno) + ppt->line = lineno - baseline; + else if (func) + ppt->offset = addr - (unsigned long)baseaddr; + + /* Duplicate strings */ + if (func) { + ppt->function = strdup(func); if (ppt->function == NULL) { ret = -ENOMEM; goto end; } - found = true; } - + if (fname) { + ppt->file = strdup(fname); + if (ppt->file == NULL) { + if (ppt->function) { + free(ppt->function); + ppt->function = NULL; + } + ret = -ENOMEM; + goto end; + } + } end: if (dwfl) dwfl_end(dwfl); - if (ret >= 0) - ret = found ? 1 : 0; + if (ret == 0 && (fname || func)) + ret = 1; /* Found a point */ return ret; } -- cgit v1.1