(2015/03/20 10:56), He Kuang wrote: > 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 >
OK, I've checked that this solve the problem :) Acked-by: Masami Hiramatsu <[email protected]> Thank you! > Signed-off-by: He Kuang <[email protected]> > --- > 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 c5e1338..c1ccd6a 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; > -- Masami HIRAMATSU Software Platform Research Dept. Linux Technology Research Center Hitachi, Ltd., Yokohama Research Laboratory E-mail: [email protected] -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
