From: Arnaldo Carvalho de Melo <[email protected]> There are holes in syscall tables with IDs not associated with any syscall, mark those when trying to read information for syscalls, which could happen when iterating thru all syscalls from 0 to the highest numbered syscall id.
Cc: Adrian Hunter <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: Luis Cláudio Gonçalves <[email protected]> Cc: Namhyung Kim <[email protected]> Link: https://lkml.kernel.org/n/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]> --- tools/perf/builtin-trace.c | 25 +++++++++++++++++++------ 1 file changed, 19 insertions(+), 6 deletions(-) diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c index 5dae7b172291..765b998755ce 100644 --- a/tools/perf/builtin-trace.c +++ b/tools/perf/builtin-trace.c @@ -976,6 +976,7 @@ static struct syscall_fmt *syscall_fmt__find_by_alias(const char *alias) * is_exit: is this "exit" or "exit_group"? * is_open: is this "open" or "openat"? To associate the fd returned in sys_exit with the pathname in sys_enter. * args_size: sum of the sizes of the syscall arguments, anything after that is augmented stuff: pathname for openat, etc. + * nonexistent: Just a hole in the syscall table, syscall id not allocated */ struct syscall { struct tep_event *tp_format; @@ -987,6 +988,7 @@ struct syscall { } bpf_prog; bool is_exit; bool is_open; + bool nonexistent; struct tep_format_field *args; const char *name; struct syscall_fmt *fmt; @@ -1491,9 +1493,6 @@ static int trace__read_syscall_info(struct trace *trace, int id) struct syscall *sc; const char *name = syscalltbl__name(trace->sctbl, id); - if (name == NULL) - return -EINVAL; - if (id > trace->syscalls.max) { struct syscall *nsyscalls = realloc(trace->syscalls.table, (id + 1) * sizeof(*sc)); @@ -1512,8 +1511,15 @@ static int trace__read_syscall_info(struct trace *trace, int id) } sc = trace->syscalls.table + id; - sc->name = name; + if (sc->nonexistent) + return 0; + if (name == NULL) { + sc->nonexistent = true; + return 0; + } + + sc->name = name; sc->fmt = syscall_fmt__find(sc->name); snprintf(tp_name, sizeof(tp_name), "sys_enter_%s", sc->name); @@ -1811,14 +1817,21 @@ static struct syscall *trace__syscall_info(struct trace *trace, return NULL; } + err = -EINVAL; + if ((id > trace->syscalls.max || trace->syscalls.table[id].name == NULL) && (err = trace__read_syscall_info(trace, id)) != 0) goto out_cant_read; - err = -EINVAL; - if ((id > trace->syscalls.max || trace->syscalls.table[id].name == NULL)) + if (id > trace->syscalls.max) goto out_cant_read; + if (trace->syscalls.table[id].name == NULL) { + if (trace->syscalls.table[id].nonexistent) + return NULL; + goto out_cant_read; + } + return &trace->syscalls.table[id]; out_cant_read: -- 2.21.0
