Messages in this thread | | | Date | Mon, 22 Feb 2010 18:15:20 +0100 | From | Frederic Weisbecker <> | Subject | Re: [GIT PULL] perf fixes |
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On Mon, Feb 22, 2010 at 09:01:39AM -0800, Linus Torvalds wrote: > > > On Mon, 22 Feb 2010, Ingo Molnar wrote: > > > > The reason i'm sending them post -rc8 is the fix for the Wine breakage from > > Frederic, which would be nice to see resolved in -final. > > Umm. That commit seems to be crap. > > Yes, it was wrong to not allow a NULL address breakpoint. But if you call > kallsyms_lookup_name(), you should check the "I couldn't find it" end > result for _that_ case, and 0 is the correct check there. > > So the code _should_ do something like > > if (info->name) { > info->address = kallsyms_lookup_name(info->name); > if (!info->address) > return -EINVAL; > } > > and that would correctly handle both the NULL original address _and_ the > name lookup failure.
Ah you're right. That part in itself is buggy. Fortunately this won't ever be reached because we don't use the info->name field anymore . It's a field I forgot to remove when I re-adapted the new hw-breakpoint API on top of perf. The name resolution (used by the ksym tracer and the hw-breakpoint sample only) is done in an upper layer now, and never stored in the arch back end in any case.
I'll remove this field and the associated dead-code for .34
Thanks.
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