From: marc.zyngier@arm•com (Marc Zyngier)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH] irqchip: gicv3-its: fix ITS CPU init
Date: Fri, 09 Jan 2015 16:10:30 +0000 [thread overview]
Message-ID: <54AFFD76.7060401@arm.com> (raw)
In-Reply-To: <1420818645-2349-1-git-send-email-vladimir.murzin@arm.com>
Hi Vladimir,
On 09/01/15 15:50, Vladimir Murzin wrote:
> We skip initialisation of ITS in case the device-tree has no
> corresponding description, but we are still accessing to ITS bits while
> setting CPU interface what leads to the kernel panic:
>
> ITS: No ITS available, not enabling LPIs
> CPU0: found redistributor 0 region 0:0x000000002f100000
> Unable to handle kernel NULL pointer dereference at virtual address 00000000
> pgd = ffffffc0007fb000
> [00000000] *pgd=00000000fc407003, *pud=00000000fc407003, *pmd=00000000fc408003, *pte=006000002f000707
> Internal error: Oops: 96000005 [#1] PREEMPT SMP
> Modules linked in:
> CPU: 0 PID: 0 Comm: swapper/0 Not tainted 3.19.0-rc2+ #318
> Hardware name: FVP Base (DT)
> task: ffffffc00077edb0 ti: ffffffc00076c000 task.ti: ffffffc00076c000
> PC is at its_cpu_init+0x2c/0x320
> LR is at gic_cpu_init+0x168/0x1bc
>
> It happens in gic_rdists_supports_plpis() because gic_rdists is NULL.
> The gic_rdists is set to non-NULL only when ITS node is presented in
> the device-tree.
>
> Fix this by moving the call to gic_rdists_supports_plpis() inside the
> !list_empty(&its_nodes) block, because it is that list that guards the
> validity of the rest of the information in this driver.
>
> Signed-off-by: Vladimir Murzin <vladimir.murzin@arm•com>
Looks good to me.
Acked-by: Marc Zyngier <marc.zyngier@arm•com>
M.
> ---
> drivers/irqchip/irq-gic-v3-its.c | 9 ++++-----
> 1 file changed, 4 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
> index 86e4684..128a12b 100644
> --- a/drivers/irqchip/irq-gic-v3-its.c
> +++ b/drivers/irqchip/irq-gic-v3-its.c
> @@ -1382,12 +1382,11 @@ static bool gic_rdists_supports_plpis(void)
>
> int its_cpu_init(void)
> {
> - if (!gic_rdists_supports_plpis()) {
> - pr_info("CPU%d: LPIs not supported\n", smp_processor_id());
> - return -ENXIO;
> - }
> -
> if (!list_empty(&its_nodes)) {
> + if (!gic_rdists_supports_plpis()) {
> + pr_info("CPU%d: LPIs not supported\n", smp_processor_id());
> + return -ENXIO;
> + }
> its_cpu_init_lpis();
> its_cpu_init_collection();
> }
>
--
Jazz is not dead. It just smells funny...
next prev parent reply other threads:[~2015-01-09 16:10 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-01-09 15:50 [PATCH] irqchip: gicv3-its: fix ITS CPU init Vladimir Murzin
2015-01-09 16:10 ` Marc Zyngier [this message]
2015-01-23 10:03 ` Vladimir Murzin
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=54AFFD76.7060401@arm.com \
--to=marc.zyngier@arm$(echo .)com \
--cc=linux-arm-kernel@lists$(echo .)infradead.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox