Commit-ID: 05c3dc2c4b60387769cbe73174347de4cf85f0c9
Gitweb: http://git.kernel.org/tip/05c3dc2c4b60387769cbe73174347de4cf85f0c9
Author: Suresh Siddha <suresh.b.siddha@xxxxxxxxx>
AuthorDate: Mon, 16 Mar 2009 17:05:03 -0700
Commit: H. Peter Anvin <hpa@xxxxxxxxxxxxxxx>
CommitDate: Tue, 17 Mar 2009 15:45:29 -0700
x86, ioapic: Fix non atomic allocation with interrupts disabled
Impact: fix possible race
save_mask_IO_APIC_setup() was using non atomic memory allocation while getting
called with interrupts disabled. Fix this by splitting this into two different
function. Allocation part save_IO_APIC_setup() now happens before
disabling interrupts.
Signed-off-by: Suresh Siddha <suresh.b.siddha@xxxxxxxxx>
Signed-off-by: H. Peter Anvin <hpa@xxxxxxxxxxxxxxx>
---
arch/x86/include/asm/io_apic.h | 3 ++-
arch/x86/kernel/apic/apic.c | 11 ++++++-----
arch/x86/kernel/apic/io_apic.c | 34 +++++++++++++++++++++++-----------
3 files changed, 31 insertions(+), 17 deletions(-)
diff --git a/arch/x86/include/asm/io_apic.h b/arch/x86/include/asm/io_apic.h
index ffcd08f..373cc2b 100644
--- a/arch/x86/include/asm/io_apic.h
+++ b/arch/x86/include/asm/io_apic.h
@@ -162,7 +162,8 @@ extern int (*ioapic_renumber_irq)(int ioapic, int irq);
extern void ioapic_init_mappings(void);
#ifdef CONFIG_X86_64
-extern int save_mask_IO_APIC_setup(void);
+extern int save_IO_APIC_setup(void);
+extern void mask_IO_APIC_setup(void);
extern void restore_IO_APIC_setup(void);
extern void reinit_intr_remapped_IO_APIC(int);
#endif
diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c
index 699f8cf..85eb8e1 100644
--- a/arch/x86/kernel/apic/apic.c
+++ b/arch/x86/kernel/apic/apic.c
@@ -1334,15 +1334,16 @@ void __init enable_IR_x2apic(void)
return;
}
- local_irq_save(flags);
- mask_8259A();
-
- ret = save_mask_IO_APIC_setup();
+ ret = save_IO_APIC_setup();
if (ret) {
pr_info("Saving IO-APIC state failed: %d\n", ret);
goto end;
}
+ local_irq_save(flags);
+ mask_IO_APIC_setup();
+ mask_8259A();
+
ret = enable_intr_remapping(1);
if (ret && x2apic_preenabled) {
@@ -1367,10 +1368,10 @@ end_restore:
else
reinit_intr_remapped_IO_APIC(x2apic_preenabled);
-end:
unmask_8259A();
local_irq_restore(flags);
+end:
if (!ret) {
if (!x2apic_preenabled)
pr_info("Enabled x2apic and interrupt-remapping\n");
diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
index cf27795..ff1759a 100644
--- a/arch/x86/kernel/apic/io_apic.c
+++ b/arch/x86/kernel/apic/io_apic.c
@@ -853,9 +853,9 @@ __setup("pirq=", ioapic_pirq_setup);
static struct IO_APIC_route_entry *early_ioapic_entries[MAX_IO_APICS];
/*
- * Saves and masks all the unmasked IO-APIC RTE's
+ * Saves all the IO-APIC RTE's
*/
-int save_mask_IO_APIC_setup(void)
+int save_IO_APIC_setup(void)
{
union IO_APIC_reg_01 reg_01;
unsigned long flags;
@@ -880,16 +880,9 @@ int save_mask_IO_APIC_setup(void)
}
for (apic = 0; apic < nr_ioapics; apic++)
- for (pin = 0; pin < nr_ioapic_registers[apic]; pin++) {
- struct IO_APIC_route_entry entry;
-
- entry = early_ioapic_entries[apic][pin] =
+ for (pin = 0; pin < nr_ioapic_registers[apic]; pin++)
+ early_ioapic_entries[apic][pin] =
ioapic_read_entry(apic, pin);
- if (!entry.mask) {
- entry.mask = 1;
- ioapic_write_entry(apic, pin, entry);
- }
- }
return 0;
@@ -902,6 +895,25 @@ nomem:
return -ENOMEM;
}
+void mask_IO_APIC_setup(void)
+{
+ int apic, pin;
+
+ for (apic = 0; apic < nr_ioapics; apic++) {
+ if (!early_ioapic_entries[apic])
+ break;
+ for (pin = 0; pin < nr_ioapic_registers[apic]; pin++) {
+ struct IO_APIC_route_entry entry;
+
+ entry = early_ioapic_entries[apic][pin];
+ if (!entry.mask) {
+ entry.mask = 1;
+ ioapic_write_entry(apic, pin, entry);
+ }
+ }
+ }
+}
+
void restore_IO_APIC_setup(void)
{
int apic, pin;
--
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