Fix application + uffd hangs due to not handling page faults #10448
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j-xiong
reviewed
Oct 9, 2024
prov/util/src/util_mem_monitor.c
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| ret = ioctl(uffd.fd, UFFDIO_ZEROPAGE, &zp); | ||
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| if (0 == ret) { /* success */ |
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Please put the constant at the right side of the comparison. Not about which way is better, but to keep the convention consistent. Same for other similar instances.
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Will do. Also, I think this PR can be squashed into a single commit.
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Please also fix those similar places that this comment applies to.
In order to receive unmap events, uffd uses 'mode missing' when registering memory regions. This implies getting page fault events as well. So handle them by returning a zero-filled page. Page faults come in 3 flavors: reads, writes and writes to protected pages. The only ones we can handle are writes to non-backed pages. Signed-off-by: Mike Uttormark <mike.uttormark@hpe.com> Signed-off-by: Ian Ziemba <ian.ziemba@hpe.com>
j-xiong
approved these changes
Oct 10, 2024
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In order to receive unmap events, uffd uses 'mode missing' when registering memory regions. This implies getting page fault events as well. So handle them by returning a zero-filled page.