[tip:x86/apic] x86, ioapic: Fix potential resume deadlock

From: tip-bot for Daniel J Blueman
Date: Fri May 20 2011 - 09:37:24 EST

Commit-ID: b64ce24daffb634b5b3133a2e411bd4de50654e8
Gitweb: http://git.kernel.org/tip/b64ce24daffb634b5b3133a2e411bd4de50654e8
Author: Daniel J Blueman <daniel.blueman@xxxxxxxxx>
AuthorDate: Wed, 18 May 2011 16:31:31 -0700
Committer: Ingo Molnar <mingo@xxxxxxx>
CommitDate: Fri, 20 May 2011 13:40:41 +0200

x86, ioapic: Fix potential resume deadlock

Fix a potential deadlock when resuming; here the calling
function has disabled interrupts, so we cannot sleep.

Change the memory allocation flag from GFP_KERNEL to GFP_ATOMIC.

TODO: We can do away with this memory allocation during resume
by reusing the ioapic suspend/resume code that uses boot time
allocated buffers, but we want to keep this -stable patch

Signed-off-by: Daniel J Blueman <daniel.blueman@xxxxxxxxx>
Signed-off-by: Suresh Siddha <suresh.b.siddha@xxxxxxxxx>
Cc: <stable@xxxxxxxxxx> # v2.6.38/39
Link: http://lkml.kernel.org/r/20110518233157.385970138@xxxxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxx>
arch/x86/kernel/apic/io_apic.c | 4 ++--
1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
index 45fd33d..df63620 100644
--- a/arch/x86/kernel/apic/io_apic.c
+++ b/arch/x86/kernel/apic/io_apic.c
@@ -621,14 +621,14 @@ struct IO_APIC_route_entry **alloc_ioapic_entries(void)
struct IO_APIC_route_entry **ioapic_entries;

ioapic_entries = kzalloc(sizeof(*ioapic_entries) * nr_ioapics,
if (!ioapic_entries)
return 0;

for (apic = 0; apic < nr_ioapics; apic++) {
ioapic_entries[apic] =
kzalloc(sizeof(struct IO_APIC_route_entry) *
- nr_ioapic_registers[apic], GFP_KERNEL);
+ nr_ioapic_registers[apic], GFP_ATOMIC);
if (!ioapic_entries[apic])
goto nomem;
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/