On Wed, Oct 23, 2024 at 05:24:40PM +0100, Lorenzo Stoakes wrote: > Implement a new lightweight guard page feature, that is regions of userland > virtual memory that, when accessed, cause a fatal signal to arise.
<snip> Hi Andrew - Could you apply the below fix-patch? I realise we must handle fatal signals and conditional rescheduling in the vector_madvise() special case. Thanks! ----8<---- >From 546d7e1831c71599fc733d589e0d75f52e84826d Mon Sep 17 00:00:00 2001 From: Lorenzo Stoakes <[email protected]> Date: Fri, 25 Oct 2024 18:05:48 +0100 Subject: [PATCH] mm: yield on fatal signal/cond_sched() in vector_madvise() While we have to treat -ERESTARTNOINTR specially here as we are looping through a vector of operations and can't simply restart the entire operation, we mustn't hold up fatal signals or RT kernels. --- mm/madvise.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/mm/madvise.c b/mm/madvise.c index 48eba25e25fe..127aa5d86656 100644 --- a/mm/madvise.c +++ b/mm/madvise.c @@ -1713,8 +1713,14 @@ static ssize_t vector_madvise(struct mm_struct *mm, struct iov_iter *iter, * we have already rescinded locks, it should be no problem to * simply try again. */ - if (ret == -ERESTARTNOINTR) + if (ret == -ERESTARTNOINTR) { + if (fatal_signal_pending(current)) { + ret = -EINTR; + break; + } + cond_resched(); continue; + } if (ret < 0) break; iov_iter_advance(iter, iter_iov_len(iter)); -- 2.47.0
