Re: [PATCH 1/6] CRISv32: don't enable irqs in INIT_THREAD

Jesper Nilsson
2015-02-20T00:27:59Z

On Thu, Feb 19, 2015 at 08:29:51PM +0100, Rabin Vincent wrote:
> INIT_THREAD enables interrupts in the thread_struct's saved flags. This
> means that interrupts get enabled in the middle of context_switch()
> while switching to new tasks that get forked off the init task during
> boot. Don't do this.
>
> Fixes the following splat on boot with spinlock debugging on:
>
> BUG: spinlock cpu recursion on CPU#0, swapper/2
> lock: runqueues+0x0/0x47c, .magic: dead4ead, .owner: swapper/0,
> .owner_cpu: 0
> CPU: 0 PID: 2 Comm: swapper Not tainted 3.19.0-08796-ga747b55 #285
>
> Call Trace:
> [<c0032b80>] spin_bug+0x2a/0x36
> [<c0032c98>] do_raw_spin_lock+0xa2/0x126
> [<c01964b0>] _raw_spin_lock+0x20/0x2a
> [<c00286c8>] scheduler_tick+0x22/0x76
> [<c003db2c>] update_process_times+0x5e/0x72
> [<c0007a94>] timer_interrupt+0x4e/0x6a
> [<c00378d6>] handle_irq_event_percpu+0x54/0xf2
> [<c00379c4>] handle_irq_event+0x50/0x74
> [<c003988e>] handle_simple_irq+0x6c/0xbe
> [<c0037270>] generic_handle_irq+0x2a/0x36
> [<c0004c40>] do_IRQ+0x38/0x84
> [<c000662e>] crisv32_do_IRQ+0x54/0x60
> [<c0006204>] IRQ0x4b_interrupt+0x34/0x3c
> [<c0192baa>] __schedule+0x24a/0x532
> [<c00056b4>] ret_from_kernel_thread+0x0/0x14
>
> Signed-off-by: Rabin Vincent <rabin@rab.in>

Looks good, adding to the CRIS-tree.

/^JN - Jesper Nilsson
--
Jesper Nilsson -- jesper.nilsson@axis.com