Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758804Ab0GPSKQ (ORCPT ); Fri, 16 Jul 2010 14:10:16 -0400 Received: from casper.infradead.org ([85.118.1.10]:49049 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758771Ab0GPSJs (ORCPT ); Fri, 16 Jul 2010 14:09:48 -0400 From: Arnaldo Carvalho de Melo To: Ingo Molnar Cc: linux-kernel@vger.kernel.org, Masami Hiramatsu , Ingo Molnar , Arnaldo Carvalho de Melo Subject: [PATCH 2/3] perf probe: Support comp_dir to find an absolute source path Date: Fri, 16 Jul 2010 15:09:32 -0300 Message-Id: <1279303773-27861-3-git-send-email-acme@infradead.org> X-Mailer: git-send-email 1.6.2.5 In-Reply-To: <1279303773-27861-1-git-send-email-acme@infradead.org> References: <1279303773-27861-1-git-send-email-acme@infradead.org> X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4604 Lines: 148 From: Masami Hiramatsu Gcc generates DW_AT_comp_dir and stores relative source path if building kernel without O= option. In that case, perf probe --line sometimes doesn't work without --source option, because it tries to access relative source path. This adds DW_AT_comp_dir support to perf probe for finding an absolute source path when no --source option. LKML-Reference: <4C36EBE7.3060802@hitachi.com> Cc: Ingo Molnar Signed-off-by: Masami Hiramatsu Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/probe-event.c | 34 ++++++++++++++++++++++------------ tools/perf/util/probe-event.h | 1 + tools/perf/util/probe-finder.c | 21 +++++++++++++++++++++ 3 files changed, 44 insertions(+), 12 deletions(-) diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c index 8d08e75..4445a1e 100644 --- a/tools/perf/util/probe-event.c +++ b/tools/perf/util/probe-event.c @@ -201,28 +201,38 @@ static int try_to_find_kprobe_trace_events(struct perf_probe_event *pev, * a newly allocated path on success. * Return 0 if file was found and readable, -errno otherwise. */ -static int get_real_path(const char *raw_path, char **new_path) +static int get_real_path(const char *raw_path, const char *comp_dir, + char **new_path) { - if (!symbol_conf.source_prefix) { - if (access(raw_path, R_OK) == 0) { - *new_path = strdup(raw_path); - return 0; - } else - return -errno; + const char *prefix = symbol_conf.source_prefix; + + if (!prefix) { + if (raw_path[0] != '/' && comp_dir) + /* If not an absolute path, try to use comp_dir */ + prefix = comp_dir; + else { + if (access(raw_path, R_OK) == 0) { + *new_path = strdup(raw_path); + return 0; + } else + return -errno; + } } - *new_path = malloc((strlen(symbol_conf.source_prefix) + - strlen(raw_path) + 2)); + *new_path = malloc((strlen(prefix) + strlen(raw_path) + 2)); if (!*new_path) return -ENOMEM; for (;;) { - sprintf(*new_path, "%s/%s", symbol_conf.source_prefix, - raw_path); + sprintf(*new_path, "%s/%s", prefix, raw_path); if (access(*new_path, R_OK) == 0) return 0; + if (!symbol_conf.source_prefix) + /* In case of searching comp_dir, don't retry */ + return -errno; + switch (errno) { case ENAMETOOLONG: case ENOENT: @@ -318,7 +328,7 @@ int show_line_range(struct line_range *lr) /* Convert source file path */ tmp = lr->path; - ret = get_real_path(tmp, &lr->path); + ret = get_real_path(tmp, lr->comp_dir, &lr->path); free(tmp); /* Free old path */ if (ret < 0) { pr_warning("Failed to find source file. (%d)\n", ret); diff --git a/tools/perf/util/probe-event.h b/tools/perf/util/probe-event.h index bc06d3e..ed362ac 100644 --- a/tools/perf/util/probe-event.h +++ b/tools/perf/util/probe-event.h @@ -86,6 +86,7 @@ struct line_range { int end; /* End line number */ int offset; /* Start line offset */ char *path; /* Real path name */ + char *comp_dir; /* Compile directory */ struct list_head line_list; /* Visible lines */ }; diff --git a/tools/perf/util/probe-finder.c b/tools/perf/util/probe-finder.c index a934a36..37dcdb6 100644 --- a/tools/perf/util/probe-finder.c +++ b/tools/perf/util/probe-finder.c @@ -144,6 +144,15 @@ static const char *cu_find_realpath(Dwarf_Die *cu_die, const char *fname) return src; } +/* Get DW_AT_comp_dir (should be NULL with older gcc) */ +static const char *cu_get_comp_dir(Dwarf_Die *cu_die) +{ + Dwarf_Attribute attr; + if (dwarf_attr(cu_die, DW_AT_comp_dir, &attr) == NULL) + return NULL; + return dwarf_formstring(&attr); +} + /* Compare diename and tname */ static bool die_compare_name(Dwarf_Die *dw_die, const char *tname) { @@ -1374,6 +1383,7 @@ int find_line_range(int fd, struct line_range *lr) size_t cuhl; Dwarf_Die *diep; Dwarf *dbg; + const char *comp_dir; dbg = dwarf_begin(fd, DWARF_C_READ); if (!dbg) { @@ -1409,6 +1419,17 @@ int find_line_range(int fd, struct line_range *lr) } off = noff; } + + /* Store comp_dir */ + if (lf.found) { + comp_dir = cu_get_comp_dir(&lf.cu_die); + if (comp_dir) { + lr->comp_dir = strdup(comp_dir); + if (!lr->comp_dir) + ret = -ENOMEM; + } + } + pr_debug("path: %s\n", lr->path); dwarf_end(dbg); -- 1.6.2.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/