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stand/kmem_zalloc: panic when a M_WAITOK allocation fails
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Authored by imp on Jul 8 2021, 5:41 AM.

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Summary

Malloc() might return NULL, in which case we will panic with a NULL
pointer deref. Make it panic when the allocation fails to preserve the
postcondtion that we never return a non-NULL value.

PR: 249859
Sponsored by: Netflix

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R10 FreeBSD src repository
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Event Timeline

imp requested review of this revision.Jul 8 2021, 5:41 AM
imp created this revision.
imp added inline comments.
sys/sys/malloc.h
321

This crept in because we never were testing flags before.

sys/sys/malloc.h
307

Shouldn't this order be reversed? or maybe create inline [function] instead? just thinking...

sys/sys/malloc.h
307

Order of what?
It can't be an inline function because I want FILE and LINE and I didn't see a good way to get that with an inline function.

308

This should be if (p == 0 && (flags & M_WAITOK) != 0)

update and make sure p == NULL before panicing.

Seems good, thanks!

sys/sys/malloc.h
307

Order of what?
It can't be an inline function because I want FILE and LINE and I didn't see a good way to get that with an inline function.

This revision is now accepted and ready to land.Jul 9 2021, 6:40 AM