Messages in this thread Patch in this message | | | Date | Sun, 28 Dec 2008 16:53:02 -0800 | From | Yinghai Lu <> | Subject | Re: [git pull] sparseirq / irq updates for v2.6.29 |
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Yinghai Lu wrote: > 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 > >
or this one
[PATCH] sparseirq: move weak function to chip.c v2
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 | 4 ++++ kernel/irq/chip.c | 5 +++++ kernel/irq/handle.c | 5 ----- 3 files changed, 9 insertions(+), 5 deletions(-)
Index: linux-2.6/init/main.c =================================================================== --- linux-2.6.orig/init/main.c +++ linux-2.6/init/main.c @@ -544,11 +544,15 @@ void __init __weak thread_info_cache_ini int __init __weak arch_early_irq_init(void) { + printk(KERN_DEBUG "calling __weak arch_early_irq_init()\n"); + return 0; } int __init __weak early_irq_init(void) { + printk(KERN_DEBUG "calling __weak early_irq_init()\n"); + return arch_early_irq_init(); } 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 +18,11 @@ #include "internals.h" +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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