From 0560a0c4a12a45def9700e7ec3215da102cf914b Mon Sep 17 00:00:00 2001 From: He Kuang Date: Fri, 20 Mar 2015 09:56:56 +0800 Subject: [PATCH] perf probe: Fix failure to add multiple probes without debuginfo Perf tries to find probe function addresses from map when debuginfo could not be found. To the first added function, the value of ref_reloc_sym was set in maps__set_kallsyms_ref_reloc_sym() and can be obtained from host_machine->kmaps->maps. After that, new maps are added to host_machine->kmaps->maps in dso__load_kcore(), all these new added maps do not have a valid ref_reloc_sym. When adding a second function, get_target_map() may get a map without valid ref_reloc_sym, and raise the error "Relocated base symbol is not found". Fix this by using kernel_get_ref_reloc_sym() to get ref_reloc_sym. This problem can be reproduced as following: $ perf probe --add='sys_write' --add='sys_open' Relocated base symbol is not found! Error: Failed to add events. After this patch: $ perf probe --add='sys_write' --add='sys_open' Added new event: probe:sys_write (on sys_write) You can now use it in all perf tools, such as: perf record -e probe:sys_write -aR sleep 1 Added new event: probe:sys_open (on sys_open) You can now use it in all perf tools, such as: perf record -e probe:sys_open -aR sleep 1 Signed-off-by: He Kuang Tested-by: Arnaldo Carvalho de Melo Tested-by: Masami Hiramatsu Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Wang Nan Link: http://lkml.kernel.org/r/1426816616-2394-1-git-send-email-hekuang@huawei.com Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/probe-event.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c index f272a711ad15..6b95985db5b0 100644 --- a/tools/perf/util/probe-event.c +++ b/tools/perf/util/probe-event.c @@ -2507,7 +2507,6 @@ static int find_probe_trace_events_from_map(struct perf_probe_event *pev, int max_tevs, const char *target) { struct map *map = NULL; - struct kmap *kmap = NULL; struct ref_reloc_sym *reloc_sym = NULL; struct symbol *sym; struct probe_trace_event *tev; @@ -2540,8 +2539,7 @@ static int find_probe_trace_events_from_map(struct perf_probe_event *pev, } if (!pev->uprobes && !pp->retprobe) { - kmap = map__kmap(map); - reloc_sym = kmap->ref_reloc_sym; + reloc_sym = kernel_get_ref_reloc_sym(); if (!reloc_sym) { pr_warning("Relocated base symbol is not found!\n"); ret = -EINVAL;