Messages in this thread | | | Date | Thu, 5 Dec 2019 10:32:29 +0100 | From | Peter Zijlstra <> | Subject | Re: [PATCH] Silence an uninitialized variable warning |
| |
On Wed, Dec 04, 2019 at 09:42:47PM +0300, Dan Carpenter wrote:
> > The current code has this: > > > > static int __init syscall_enter_define_fields(struct trace_event_call *call) > > { > > struct syscall_trace_enter trace; > > struct syscall_metadata *meta = call->data; > > int ret; > > int i; > > int offset = offsetof(typeof(trace), args); > > > > ret = trace_define_field(call, SYSCALL_FIELD(int, nr, __syscall_nr), > > FILTER_OTHER); > > In linux-next this ret = trace_define_field() assignment is removed. > That was commit 60fdad00827c ("ftrace: Rework event_create_dir()").
Yep, mea culpa.
> > if (ret) > > return ret; > > > > for (i = 0; i < meta->nb_args; i++) { > > ret = trace_define_field(call, meta->types[i], > > meta->args[i], offset, > > sizeof(unsigned long), 0, > > FILTER_OTHER); > > offset += sizeof(unsigned long); > > } > > > > return ret; > > } > > > > > > How can ret possibly be uninitialized? > > I should have written this commit more carefully and verified whether > meta->nb_args can actually be zero instead of just assuming it was a > false positive...
Right, I'm thinking this is in fact possible. We have syscalls without arguments (sys_sched_yield for exmaple).
| |