Re: 2.6.17-rc5-mm1

Ingo Molnar
2006-06-01T06:14:17Z

* Andrew Morton <akpm@osdl.org> wrote:

> > [ 36.489028] Unable to handle kernel NULL pointer dereference at 0000000000000000 RIP:
> > [ 36.500245] [<0000000000000000>] stext+0x7feff0e8/0xe8

> > [ 37.103370] Call Trace:
> > [ 37.140640] <IRQ> [<ffffffff8010b711>] do_IRQ+0x4f/0x5e
> > [ 37.167285] [<ffffffff80107d21>] mwait_idle+0x0/0x53
> > [ 37.193322] [<ffffffff80109708>] ret_from_intr+0x0/0xa
> > [ 37.219723] <EOI>

Randy, do you have an MSI-X device perhaps? Could you try the patch
below?

Ingo

------------------------------------------------------
Subject: genirq MSI fixes
From: Ingo Molnar <mingo@elte.hu>

This is a fixed up and cleaned up replacement for genirq-msi-fixes.patch,
which should solve the i386 4KSTACKS problem. I also added Ben's idea of
pushing the __do_IRQ() check into generic_handle_irq().

I booted this with MSI enabled, but i only have MSI devices, not MSI-X
devices. I'd still expect MSI-X to work now.

irqchip migration helper: call __do_IRQ() if a descriptor is attached to an
irqtype-style controller. This also fixes MSI-X IRQ handling on i386 and
x86_64.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Roland Dreier <rolandd@cisco.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
---

arch/i386/kernel/irq.c | 5 +++++
include/linux/irq.h | 27 ++++++++++++++++-----------
2 files changed, 21 insertions(+), 11 deletions(-)

diff -puN arch/i386/kernel/irq.c~genirq-msi-fixes-2 arch/i386/kernel/irq.c
--- devel/arch/i386/kernel/irq.c~genirq-msi-fixes-2 2006-05-30 23:47:30.000000000 -0700
+++ devel-akpm/arch/i386/kernel/irq.c 2006-05-30 23:47:30.000000000 -0700
@@ -77,6 +77,10 @@ fastcall unsigned int do_IRQ(struct pt_r
}
#endif

+ if (!irq_desc[irq].handle_irq) {
+ __do_IRQ(irq, regs);
+ goto out_exit;
+ }
#ifdef CONFIG_4KSTACKS

curctx = (union irq_ctx *) current_thread_info();
@@ -109,6 +113,7 @@ fastcall unsigned int do_IRQ(struct pt_r
#endif
desc->handle_irq(irq, desc, regs);

+out_exit:
irq_exit();

return 1;
diff -puN include/linux/irq.h~genirq-msi-fixes-2 include/linux/irq.h
--- devel/include/linux/irq.h~genirq-msi-fixes-2 2006-05-30 23:47:30.000000000 -0700
+++ devel-akpm/include/linux/irq.h 2006-05-30 23:47:30.000000000 -0700
@@ -176,17 +176,6 @@ typedef struct irq_desc irq_desc_t;
*/
#include <asm/hw_irq.h>

-/*
- * Architectures call this to let the generic IRQ layer
- * handle an interrupt:
- */
-static inline void generic_handle_irq(unsigned int irq, struct pt_regs *regs)
-{
- struct irq_desc *desc = irq_desc + irq;
-
- desc->handle_irq(irq, desc, regs);
-}
-
extern int setup_irq(unsigned int irq, struct irqaction *new);

#ifdef CONFIG_GENERIC_HARDIRQS
@@ -324,6 +313,22 @@ handle_irq_name(void fastcall (*handle)(
*/
extern fastcall unsigned int __do_IRQ(unsigned int irq, struct pt_regs *regs);

+/*
+ * Architectures call this to let the generic IRQ layer
+ * handle an interrupt. If the descriptor is attached to an
+ * irqchip-style controller then we call the ->handle_irq() handler,
+ * and it calls __do_IRQ() if it's attached to an irqtype-style controller.
+ */
+static inline void generic_handle_irq(unsigned int irq, struct pt_regs *regs)
+{
+ struct irq_desc *desc = irq_desc + irq;
+
+ if (likely(desc->handle_irq))
+ desc->handle_irq(irq, desc, regs);
+ else
+ __do_IRQ(irq, regs);
+}
+
/* Handling of unhandled and spurious interrupts: */
extern void note_interrupt(unsigned int irq, struct irq_desc *desc,
int action_ret, struct pt_regs *regs);
_