Commit b2e2fe99628c4f944c3075258e536197b5a4f3f8
1 parent
12026ea16a
Exists in
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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>
Showing 2 changed files with 9 additions and 5 deletions Side-by-side Diff
kernel/irq/handle.c
| ... | ... | @@ -86,11 +86,6 @@ |
| 86 | 86 | desc->kstat_irqs = (unsigned int *)ptr; |
| 87 | 87 | } |
| 88 | 88 | |
| 89 | -int __weak arch_init_chip_data(struct irq_desc *desc, int cpu) | |
| 90 | -{ | |
| 91 | - return 0; | |
| 92 | -} | |
| 93 | - | |
| 94 | 89 | static void init_one_irq_desc(int irq, struct irq_desc *desc, int cpu) |
| 95 | 90 | { |
| 96 | 91 | memcpy(desc, &irq_desc_init, sizeof(struct irq_desc)); |
kernel/irq/manage.c
| ... | ... | @@ -261,6 +261,15 @@ |
| 261 | 261 | } |
| 262 | 262 | EXPORT_SYMBOL(enable_irq); |
| 263 | 263 | |
| 264 | +/* | |
| 265 | + * [ Not in kernel/irq/handle.c, so that GCC does not | |
| 266 | + * inline the __weak alias: ] | |
| 267 | + */ | |
| 268 | +int __weak arch_init_chip_data(struct irq_desc *desc, int cpu) | |
| 269 | +{ | |
| 270 | + return 0; | |
| 271 | +} | |
| 272 | + | |
| 264 | 273 | static int set_irq_wake_real(unsigned int irq, unsigned int on) |
| 265 | 274 | { |
| 266 | 275 | struct irq_desc *desc = irq_to_desc(irq); |