Messages in this thread |  | | Date | Thu, 2 Jan 2020 14:53:14 -0500 | From | Joel Fernandes <> | Subject | Re: [PATCH] tracing: Fix printing ptrs in preempt/irq enable/disable events |
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On Mon, Dec 23, 2019 at 03:13:01PM -0500, Steven Rostedt wrote: > On Sat, 21 Dec 2019 18:47:41 -0500 > Joel Fernandes <joel@joelfernandes.org> wrote: > > > On Wed, Dec 04, 2019 at 09:21:15AM -0500, Steven Rostedt wrote: > > > > > > Joel, > > > > > > Any comments on this patch? > > > > Steve, it looks like this issue happens with trace-cmd not knowing what > > _stext is. If I do cat trace_pipe , then I don't see the issue as _stext is > > looked up correctly but the reporter of the bug is using trace-cmd. Is there > > a way to solve this within trace-cmd? Not knowing much about trace-cmd > > internals, I will have to defer to you on this though.. > > > > Other than this, I need to make the offset to _stext as s32 instead of u32 > > type so that the problem of the symbol location being before _stext does not > > cause overflow. > > > > Lastly, I am not super convinced that we need to store the full pointer just > > to handle a case where the offset of the symbol might be more than +-2G from > > _stext. Once we see such issue, then we can handle it. But right now the size > > of the trace buffer is utilized better by just storing the offset IMHO. > > > > Does this fix it for you?
I am guessing this question is for Antonio to try Steve's patch with trace-cmd. Meanwhile I posted a patch to fix the offset issue by changing the u32 to s32.
thanks,
- Joel
> > -- Steve > > diff --git a/lib/traceevent/event-parse.c b/lib/traceevent/event-parse.c > index 4fd3907e..dc705dd2 100644 > --- a/lib/traceevent/event-parse.c > +++ b/lib/traceevent/event-parse.c > @@ -3595,6 +3595,45 @@ tep_find_event_by_name(struct tep_handle *tep, > return event; > } > > +static unsigned long long test_for_symbol(struct tep_handle *tep, > + struct tep_print_arg *arg) > +{ > + unsigned long long val = 0; > + struct func_list *item = tep->funclist; > + char *func; > + int i; > + > + if (isdigit(arg->atom.atom[0])) > + return 0; > + > + for (i = 0; i < (int)tep->func_count; i++) { > + unsigned long long addr; > + const char *name; > + > + if (tep->func_map) { > + addr = tep->func_map[i].addr; > + name = tep->func_map[i].func; > + } else if (item) { > + addr = item->addr; > + name = item->func; > + item = item->next; > + } else > + break; > + > + if (strcmp(arg->atom.atom, name) == 0) { > + val = addr; > + break; > + } > + } > + > + func = realloc(arg->atom.atom, 32); > + if (func) { > + snprintf(func, 32, "%lld", val); > + arg->atom.atom = func; > + } > + return val; > +} > + > static unsigned long long > eval_num_arg(void *data, int size, struct tep_event *event, struct tep_print_arg *arg) > { > @@ -3611,7 +3650,10 @@ eval_num_arg(void *data, int size, struct tep_event *event, struct tep_print_arg > /* ?? */ > return 0; > case TEP_PRINT_ATOM: > - return strtoull(arg->atom.atom, NULL, 0); > + val = strtoull(arg->atom.atom, NULL, 0); > + if (!val) > + val = test_for_symbol(tep, arg); > + return val; > case TEP_PRINT_FIELD: > if (!arg->field.field) { > arg->field.field = tep_find_any_field(event, arg->field.name);
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