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author | andrew <andrew@FreeBSD.org> | 2015-05-23 23:08:16 +0000 |
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committer | andrew <andrew@FreeBSD.org> | 2015-05-23 23:08:16 +0000 |
commit | e6b664c390af88d4a87208bc042ce503da664c3b (patch) | |
tree | d78186deeec09d550c81b1ad26d887f11aee2684 /usr.bin/su | |
parent | 0926af4e2a44b22e2538a698379dc29593568f82 (diff) | |
download | FreeBSD-src-e6b664c390af88d4a87208bc042ce503da664c3b.zip FreeBSD-src-e6b664c390af88d4a87208bc042ce503da664c3b.tar.gz |
Fix a lock up where we enter swapper() with interrupts disabled.
In smp_rendezvous_cpus we expect to wait for all cpus to enter
smp_rendezvous_action. If we call this holding a proc lock swapper may
attempt to also lock it, however as interrupts are disabled the cpu never
handles the ipi. Because smp_rendezvous_action waits for all signaled
cpus before contining it may get caught waiting for the cpu running swapper
as the proc mutex will be unlocked after smp_rendezvous_cpus finishes.
The fix is to enable interrupts in the configure stage as we should be
doing.
MFC after: 1 week
Diffstat (limited to 'usr.bin/su')
0 files changed, 0 insertions, 0 deletions