Messages in this thread | | | From | Nadav Amit <> | Subject | Re: [PATCH v2 1/6] Fix "x86/alternatives: Lockdep-enforce text_mutex in text_poke*()" | Date | Thu, 6 Sep 2018 19:42:14 +0000 |
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at 12:40 PM, Peter Zijlstra <peterz@infradead.org> wrote:
> On Sun, Sep 02, 2018 at 10:32:19AM -0700, Nadav Amit wrote: >> text_mutex is expected to be held before text_poke() is called, but we >> cannot add a lockdep assertion since kgdb does not take it, and instead >> *supposedly* ensures the lock is not taken and will not be acquired by >> any other core while text_poke() is running. >> >> The reason for the "supposedly" comment is that it is not entirely clear >> that this would be the case if gdb_do_roundup is zero. > > Argh, that's pretty shit code... > > Not only is that text_mutex abuse ugly, so too is the fixmap usage from > IRQ context. I suppose this really does require your alternative mm > patches for text_poke().
Right, I forgot about that…
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