Messages in this thread | | | Date | Thu, 28 Sep 2017 09:41:58 +0900 | From | Sergey Senozhatsky <> | Subject | Re: [PATCH] zsmalloc: calling zs_map_object() from irq is a bug |
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On (09/26/17 17:26), Andrew Morton wrote: > > On Wed, Sep 20, 2017 at 03:39:41PM +0900, Sergey Senozhatsky wrote: > > > Use BUG_ON(in_interrupt()) in zs_map_object(). Calling this > > > function from IRQ is a bug, because we use per-CPU mappings > > > and interrupt may corrupt those buffers. > > > > > > Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> > > > > IMHO, corruption the buffer would be not enough to be a BUG_ON > > which stop the system fully so user loses any chances to shut > > down smooth/hunt it down. > > > > More serious thing of our case is that it can leak other user's > > data by overwriting, which is more concern I am thinking now. > > > > In an off-list email Linus has basically stated that all new uses of > BUG_ON should include words in the changelog or code comments > explaining why it is justifiable to kill the machine when the condition > triggers. > > So can we please have a v2 with the appropriate comment?
ah, OK. will follow up.
-ss
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