Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756697AbbHZHl1 (ORCPT ); Wed, 26 Aug 2015 03:41:27 -0400 Received: from szxga01-in.huawei.com ([58.251.152.64]:2363 "EHLO szxga01-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756540AbbHZHkt (ORCPT ); Wed, 26 Aug 2015 03:40:49 -0400 From: Wang Nan To: , , CC: , , , Subject: [PATCH v2 2/4] perf probe: Fix list result when address is zero Date: Wed, 26 Aug 2015 07:40:23 +0000 Message-ID: <1440574825-221187-3-git-send-email-wangnan0@huawei.com> X-Mailer: git-send-email 1.8.3.4 In-Reply-To: <1440574825-221187-1-git-send-email-wangnan0@huawei.com> References: <1440574825-221187-1-git-send-email-wangnan0@huawei.com> MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.107.193.248] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3136 Lines: 91 When manually added uprobe point with zero address, 'perf probe -l' reports error. For example: # echo p:probe_libc/abs_0 /path/to/lib.bin:0x0 arg1=%ax > \ /sys/kernel/debug/tracing/uprobe_events # perf probe -l Error: Failed to show event list. Probing at 0x0 is possible and useful when lib.bin is not a normal shared object but is manually mapped. However, in this case kernel report: # cat /sys/kernel/debug/tracing/uprobe_events p:probe_libc/abs_0 /tmp/oxygen_root/lib64/libc-2.18.so:0x (null) arg1=%ax This patch supports the above kernel output. In addition, this patch also fixes convert_to_perf_probe_point() that, if failed to find probe point from both of dwarf and map, in all cases pp->function should be filled with a strdup() result, or the following ENOMEM error code is incorrect. Remove !tp->module && !is_kprobe condition so always use address to build function name if symbol is not found. Signed-off-by: Wang Nan Cc: Arnaldo Carvalho de Melo Cc: Ingo Molnar Cc: Masami Hiramatsu Cc: Namhyung Kim Cc: Steven Rostedt --- tools/perf/util/probe-event.c | 30 ++++++++++++++++++++++++++---- 1 file changed, 26 insertions(+), 4 deletions(-) diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c index ef325a2..3ce223d 100644 --- a/tools/perf/util/probe-event.c +++ b/tools/perf/util/probe-event.c @@ -1521,9 +1521,31 @@ int parse_probe_trace_command(const char *cmd, struct probe_trace_event *tev) } else p = argv[1]; fmt1_str = strtok_r(p, "+", &fmt); - if (fmt1_str[0] == '0') /* only the address started with 0x */ - tp->address = strtoul(fmt1_str, NULL, 0); - else { + /* only the address started with 0x */ + if (fmt1_str[0] == '0') { + /* + * Fix a special case: + * if address == 0, kernel reports something like: + * p:probe_libc/abs_0 /lib/libc-2.18.so:0x (null) arg1=%ax + * Newer kernel may fix that, but we want to + * support old kernel also. + */ + if (strcmp(fmt1_str, "0x") == 0) { + if (!argv[2] || strcmp(argv[2], "(null)")) { + ret = -EINVAL; + goto out; + } + tp->address = 0; + + free(argv[2]); + for (i = 2; argv[i + 1] != NULL; i++) + argv[i] = argv[i + 1]; + + argv[i] = NULL; + argc -= 1; + } else + tp->address = strtoul(fmt1_str, NULL, 0); + } else { /* Only the symbol-based probe has offset */ tp->symbol = strdup(fmt1_str); if (tp->symbol == NULL) { @@ -1868,7 +1890,7 @@ static int convert_to_perf_probe_point(struct probe_trace_point *tp, if (tp->symbol) { pp->function = strdup(tp->symbol); pp->offset = tp->offset; - } else if (!tp->module && !is_kprobe) { + } else { ret = e_snprintf(buf, 128, "0x%" PRIx64, (u64)tp->address); if (ret < 0) return ret; -- 1.8.3.4 -- 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/