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powerpc/pseries: avoid blocking in irq when queuing hotplug events

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A couple of bugs in queue_hotplug_event():

1. Unchecked kmalloc result which could lead to an oops.
2. Use of GFP_KERNEL allocations in interrupt context (this code's
   only caller is ras_hotplug_interrupt()).

Use kmemdup to avoid open-coding the allocation+copy and check for
failure; use GFP_ATOMIC for both allocations.

Ultimately it probably would be better to avoid or reduce allocations
in this path if possible.

Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This commit is contained in:
Nathan Lynch 2019-05-28 18:28:01 -05:00 committed by Michael Ellerman
parent f474c28fbc
commit 348ea30f51
1 changed files with 4 additions and 4 deletions
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8
arch/powerpc/platforms/pseries/dlpar.c
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@ -390,11 +390,11 @@ void queue_hotplug_event(struct pseries_hp_errorlog *hp_errlog)
struct pseries_hp_work *work;
struct pseries_hp_errorlog *hp_errlog_copy;
hp_errlog_copy = kmalloc(sizeof(struct pseries_hp_errorlog),
GFP_KERNEL);
memcpy(hp_errlog_copy, hp_errlog, sizeof(struct pseries_hp_errorlog));
hp_errlog_copy = kmemdup(hp_errlog, sizeof(*hp_errlog), GFP_ATOMIC);
if (!hp_errlog_copy)
return;
work = kmalloc(sizeof(struct pseries_hp_work), GFP_KERNEL);
work = kmalloc(sizeof(struct pseries_hp_work), GFP_ATOMIC);
if (work) {
INIT_WORK((struct work_struct *)work, pseries_hp_work_fn);
work->errlog = hp_errlog_copy;