Messages in this thread Patch in this message |  | | | Date | Sun, 28 Dec 2008 16:28:23 -0800 | | From | Yinghai Lu <> | | Subject | Re: [git pull] sparseirq / irq updates for v2.6.29 |
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Ingo Molnar wrote: > * Ingo Molnar <mingo@elte.hu> wrote: > >> b2e2fe9: sparseirq: work around __weak alias bug > > here's that fix, standalone too. Kamalesh, i think this should finally fix > the crash you are seeing. > > Ingo > > ----------------> >>From b2e2fe99628c4f944c3075258e536197b5a4f3f8 Mon Sep 17 00:00:00 2001 > From: Ingo Molnar <mingo@elte.hu> > Date: Mon, 29 Dec 2008 00:16:45 +0100 > Subject: [PATCH] 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.
that is not enough.
need
[PATCH] sparseirq: mvoe two weak functions to chip.c
Impact: fix panic
some gcc compiler will remove the weak global blank function Linus noted that we could move those function to other unit to workaround it.
try to workaround it: 1. one time path: add printk 2. multi time path: move to chip.c
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
--- init/main.c | 9 +++------ kernel/irq/chip.c | 10 ++++++++++ kernel/irq/handle.c | 5 ----- 3 files changed, 13 insertions(+), 11 deletions(-) Index: linux-2.6/init/main.c =================================================================== --- linux-2.6.orig/init/main.c +++ linux-2.6/init/main.c @@ -542,14 +542,11 @@ void __init __weak thread_info_cache_ini { } -int __init __weak arch_early_irq_init(void) -{ - return 0; -} - int __init __weak early_irq_init(void) { - return arch_early_irq_init(); + printk(KERN_DEBUG "calling __weak early_irq_init()\n"); + + return 0; } asmlinkage void __init start_kernel(void) Index: linux-2.6/kernel/irq/chip.c =================================================================== --- linux-2.6.orig/kernel/irq/chip.c +++ linux-2.6/kernel/irq/chip.c @@ -18,6 +18,16 @@ #include "internals.h" +int __init __weak arch_early_irq_init(void) +{ + return 0; +} + +int __weak arch_init_chip_data(struct irq_desc *desc, int cpu) +{ + return 0; +} + /** * dynamic_irq_init - initialize a dynamically allocated irq * @irq: irq number to initialize Index: linux-2.6/kernel/irq/handle.c =================================================================== --- linux-2.6.orig/kernel/irq/handle.c +++ linux-2.6/kernel/irq/handle.c @@ -86,11 +86,6 @@ void init_kstat_irqs(struct irq_desc *de 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));
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