Differential D22127

Add missing M_NOWAIT flag
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Authored by rstone on Oct 23 2019, 4:21 PM.

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• hselasky
imp

Commits

rS353938: Add missing M_NOWAIT flag

Summary

The LinuxKPI linux_dma code calls PCTRIE_INSERT with a
mutex held, but does not set M_NOWAIT when allocating
nodes, leading to a potential panic. All of this code
can handle an allocation failure here, so prefer an
allocation failure to sleeping on memory.

Also fix a related case where NOWAIT/WAITOK was not
specified. In this case it's not clear whether sleeping
is allowed so be conservative and assume not. There are
a lot of other paths in this code that can fail due to
a lack of memory anyway.

Sponsored by: Dell EMC Isilon
MFC After: 1 week

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Repository

rS FreeBSD src repository - subversion

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Tests Not Applicable

Event Timeline

rstone created this revision.Oct 23 2019, 4:21 PM

Herald added a subscriber: emaste. · View Herald TranscriptOct 23 2019, 4:21 PM

Harbormaster completed remote builds in B27171: Diff 63586.Oct 23 2019, 4:21 PM

rstone added a reviewer: • hselasky.Oct 23 2019, 4:24 PM

Ping @hselasky @imp @johalun

This looks correct.
I agree with the IRC comment about a kassert in uma_zalloc for the flags, but that's not needed here.

This revision is now accepted and ready to land.Oct 23 2019, 4:36 PM

Closed by commit rS353938: Add missing M_NOWAIT flag (authored by rstone). · Explain WhyOct 23 2019, 5:20 PM

This revision was automatically updated to reflect the committed changes.

rstone added a commit: rS353938: Add missing M_NOWAIT flag.

Revision Contents
Changeset List

Path

Size

head/

sys/

compat/

linuxkpi/

common/

src/

7 lines

Diff 63590

head/sys/compat/linuxkpi/common/src/linux_pci.c

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