This fixes the following crash when booting on Tegra:
[ 123.346233] Unable to handle kernel NULL pointer dereference at
virtual address 00000000
[ 123.354346] pgd = c0004000
[ 123.357071] [00000000] *pgd=00000000
[ 123.360687] Internal error: Oops: 80000007 [#1] PREEMPT SMP ARM
[ 123.366614] Modules linked in:
[ 123.369702] CPU: 0 Not tainted
(3.8.0-rc7-next-20130212-00002-ga12b34b-dirty #21)
[ 123.377541] PC is at 0x0
[ 123.380123] LR is at tick_do_broadcast.constprop.3+0x74/0xb0
[ 123.385802] pc : [<00000000>] lr : [<c0064344>] psr: 20000193
[ 123.385802] sp : c06ede18 ip : 00000002 fp : 00000004
[ 123.397285] r10: c06e8a60 r9 : c06f4f10 r8 : c06f4ca0
[ 123.402520] r7 : 0000001c r6 : b7bf7c40 r5 : c07537d8 r4 :
00000000
[ 123.409055] r3 : 00000000 r2 : 004ac000 r1 : 00000004 r0 :
c07537e4
[ 123.415594] Flags: nzCv IRQs off FIQs on Mode SVC_32 ISA ARM
Segment kernel
[ 123.422999] Control: 10c5387d Table: 1ada804a DAC: 00000015
[ 123.428756] Process swapper/0 (pid: 0, stack limit = 0xc06ec238)
[ 123.434771] Stack: (0xc06ede18 to 0xc06ee000)
[ 123.439145] de00:
00000002 ffffffff
[ 123.447348] de20: 7fffffff c0064434 b7bec890 c0707840 b7bf7c40
0000001c 00000000 c0707800
[ 123.455547] de40: df815ad0 00000000 00000000 00000049 c072e8b3
df815a80 00000001 c022db34
[ 123.463749] de60: c022db10 c0079a14 0000001c c0b8ca68 b7bf3dc0
df815a80 df815ad0 c0707800
[ 123.471950] de80: fe000100 df9cb380 c06ec000 c04eb1ac 00000000
c0079b94 df815a80 df815ad0
[ 123.480148] dea0: 00000000 c007c7b0 c007c734 00000049 00000049
c0079410 c06e91f0 c000ec38
[ 123.488349] dec0: fe00010c c06f5048 c06edee8 c00086d4 c005dd20
c032c13c 60000113 ffffffff
[ 123.496549] dee0: c06edf1c c000e000 c06edf30 3b9aca00 b7bf2650
0000001c b718bcc0 0000001c
[ 123.504747] df00: c0b8c3e8 00000001 df9cb380 c06ec000 c04eb1ac
00000000 00000015 c06edf30
[ 123.512945] df20: c005dd20 c032c13c 60000113 ffffffff b7bf2650
0000001c 00000000 c04eb1ac
[ 123.521144] df40: 00000000 df9cb394 c0b8c3e8 c0b8c3e8 c06f9de0
c032be10 df9cb394 c0b8c3e8
[ 123.529341] df60: 00000001 c032dd30 0000004c c0b8c3e8 c0777c94
00000001 c06f9de0 00000000
[ 123.537541] df80: c072ea88 c032bf40 c06ec000 c072ea88 c06ec000
c06f43f4 c04eb1ac c000f008
[ 123.545740] dfa0: c06f4d00 00000000 c072e9c0 c0b89140 ffffffff
411fc090 3fffffff c06b47bc
[ 123.553939] dfc0: ffffffff ffffffff c06b42ec 00000000 00000000
c06ddcd0 00000000 10c5387d
[ 123.562138] dfe0: c06f43f0 c06ddccc c06f8aa4 0000406a 00000000
00008074 00000000 00000000
[ 123.570369] [<c0064344>] (tick_do_broadcast.constprop.3+0x74/0xb0)
from [<c0064434>] (tick_handle_oneshot_broadcast+0xb4/0x108)
[ 123.581897] [<c0064434>] (tick_handle_oneshot_broadcast+0xb4/0x108)
from [<c022db34>] (tegra_timer_interrupt+0x24/0x2c)
[ 123.592727] [<c022db34>] (tegra_timer_interrupt+0x24/0x2c) from
[<c0079a14>] (handle_irq_event_percpu+0x50/0x194)
[ 123.603022] [<c0079a14>] (handle_irq_event_percpu+0x50/0x194) from
[<c0079b94>] (handle_irq_event+0x3c/0x5c)
[ 123.612887] [<c0079b94>] (handle_irq_event+0x3c/0x5c) from
[<c007c7b0>] (handle_fasteoi_irq+0x7c/0x138)
[ 123.622314] [<c007c7b0>] (handle_fasteoi_irq+0x7c/0x138) from
[<c0079410>] (generic_handle_irq+0x20/0x30)
[ 123.631923] [<c0079410>] (generic_handle_irq+0x20/0x30) from
[<c000ec38>] (handle_IRQ+0x38/0x94)
[ 123.640740] [<c000ec38>] (handle_IRQ+0x38/0x94) from [<c00086d4>]
(gic_handle_irq+0x28/0x5c)
[ 123.649204] [<c00086d4>] (gic_handle_irq+0x28/0x5c) from
[<c000e000>] (__irq_svc+0x40/0x70)
[ 123.657561] Exception stack(0xc06edee8 to 0xc06edf30)
[ 123.662637] dee0: c06edf30 3b9aca00 b7bf2650
0000001c b718bcc0 0000001c
[ 123.670839] df00: c0b8c3e8 00000001 df9cb380 c06ec000 c04eb1ac
00000000 00000015 c06edf30
[ 123.679027] df20: c005dd20 c032c13c 60000113 ffffffff
[ 123.684125] [<c000e000>] (__irq_svc+0x40/0x70) from [<c032c13c>]
(cpuidle_wrap_enter+0x48/0x94)
[ 123.692858] [<c032c13c>] (cpuidle_wrap_enter+0x48/0x94) from
[<c032be10>] (cpuidle_enter_state+0x14/0x70)
[ 123.702461] [<c032be10>] (cpuidle_enter_state+0x14/0x70) from
[<c032dd30>] (cpuidle_enter_state_coupled+0x208/0x2a0)
[ 123.713013] [<c032dd30>] (cpuidle_enter_state_coupled+0x208/0x2a0)
from [<c032bf40>] (cpuidle_idle_call+0xd4/0x124)
[ 123.723475] [<c032bf40>] (cpuidle_idle_call+0xd4/0x124) from
[<c000f008>] (cpu_idle+0xb0/0x124)
[ 123.732228] [<c000f008>] (cpu_idle+0xb0/0x124) from [<c06b47bc>]
(start_kernel+0x2a4/0x2f4)
[ 123.740586] Code: bad PC value
[ 123.743668] ---[ end trace ceed8db1ca3c192e ]---
[ 123.748297] Kernel panic - not syncing: Fatal exception in interrupt
[ 125.143549] SMP: failed to stop secondary CPUs
Note that I have close to no clue what I'm doing, so the patch might be
the completely wrong thing to do. An alternative I had initially thought
about was to check for NULL before calling the clock_event_device's
.broadcast() function.
The reason why I chose to always assign .broadcast instead is that a
previous patch (3d06770: Add generic timer broadcast support) aims at
generically implementing broadcast support on ARM and providing a
tick_broadcast() implementation for this purpose so it seemed like the
right thing to do.
The above-mentioned patch for some reason removed the assignment to the
.broadcast() member for apparently no reason, so maybe that was just
done by mistake?
Signed-off-by: Thierry Reding <[email protected]>
---
arch/arm/kernel/smp.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c
index 5f73f70..472ba9d 100644
--- a/arch/arm/kernel/smp.c
+++ b/arch/arm/kernel/smp.c
@@ -467,7 +467,7 @@ void tick_broadcast(const struct cpumask *mask)
smp_cross_call(mask, IPI_TIMER);
}
#else
-#define smp_timer_broadcast NULL
+#define tick_broadcast NULL
#endif
static void broadcast_timer_set_mode(enum clock_event_mode mode,
@@ -513,6 +513,8 @@ static void __cpuinit percpu_timer_setup(void)
if (!lt_ops || lt_ops->setup(evt))
broadcast_timer_setup(evt);
+
+ evt->broadcast = tick_broadcast;
}
#ifdef CONFIG_HOTPLUG_CPU
--
1.8.1.2
--
To unsubscribe from this list: send the line "unsubscribe linux-tegra" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
