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authorIngo Molnar <mingo@elte.hu>2008-12-29 00:16:45 +0100
committerIngo Molnar <mingo@elte.hu>2008-12-29 00:19:55 +0100
commitb2e2fe99628c4f944c3075258e536197b5a4f3f8 (patch)
treead56d4853efc86c2c86e897b843a6438550d039c
parent12026ea16a618b289fcf457661aed24f57323a20 (diff)
sparseirq: work around __weak alias bug
Impact: fix boot crash if the kernel is built with certain GCC versions GCC has a bug with __weak alias functions: if the functions are in the same compilation unit as their call site, GCC can decide to inline them - and thus rob the linker of the opportunity to override the weak alias with the real thing. This can lead to the boot crash reported by Kamalesh Babulal: ACPI: Core revision 20080926 Setting APIC routing to flat BUG: unable to handle kernel NULL pointer dereference at 0000000000000000 IP: [<ffffffff8021f9a8>] add_pin_to_irq_cpu+0x14/0x74 PGD 0 Oops: 0000 [#1] SMP [...] So move the arch_init_chip_data() function from handle.c to manage.c. Reported-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
-rw-r--r--kernel/irq/handle.c5
-rw-r--r--kernel/irq/manage.c9
2 files changed, 9 insertions, 5 deletions
diff --git a/kernel/irq/handle.c b/kernel/irq/handle.c
index 157c04c3b15..c20db0be917 100644
--- a/kernel/irq/handle.c
+++ b/kernel/irq/handle.c
@@ -86,11 +86,6 @@ void init_kstat_irqs(struct irq_desc *desc, int cpu, int nr)
desc->kstat_irqs = (unsigned int *)ptr;
}
-int __weak arch_init_chip_data(struct irq_desc *desc, int cpu)
-{
- return 0;
-}
-
static void init_one_irq_desc(int irq, struct irq_desc *desc, int cpu)
{
memcpy(desc, &irq_desc_init, sizeof(struct irq_desc));
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index 46953a06f4a..c2741b02ad3 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -261,6 +261,15 @@ void enable_irq(unsigned int irq)
}
EXPORT_SYMBOL(enable_irq);
+/*
+ * [ Not in kernel/irq/handle.c, so that GCC does not
+ * inline the __weak alias: ]
+ */
+int __weak arch_init_chip_data(struct irq_desc *desc, int cpu)
+{
+ return 0;
+}
+
static int set_irq_wake_real(unsigned int irq, unsigned int on)
{
struct irq_desc *desc = irq_to_desc(irq);