Messages in this thread | | | From | Linus Torvalds <> | Date | Sun, 25 Aug 2019 09:54:28 -0700 | Subject | Re: [PATCH] /dev/mem: Bail out upon SIGKILL when reading memory. |
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On Sat, Aug 24, 2019 at 10:50 PM Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp> wrote: > > @@ -142,7 +144,7 @@ static ssize_t read_mem(struct file *file, char __user *buf, > sz = size_inside_page(p, count); > cond_resched(); > err = -EINTR; > - if (fatal_signal_pending(current)) > + if (signal_pending(current)) > goto failed; > > err = -EPERM;
So from a "likelihood of breaking" standpoint, I'd really like to make sure that the "signal_pending()" checks come at the *end* of the loop.
That way, if somebody is doing a 4-byte read from MMIO, he'll never see -EINTR.
I'm specifically thinking of tools like user-space 'lspci' etc, which I wouldn't be surprised could happen.
Also, just in case things break, I do agree with Ingo that this should be split up into several patches.
Linus
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