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authorLaurence de Bruxelles <lfdebrux@gmail.com>2022-01-01 18:41:49 +0300
committerAlexandre Belloni <alexandre.belloni@bootlin.com>2022-01-05 03:05:17 +0300
commit34127b3632b21e5c391756e724b1198eb9917981 (patch)
treefa92a449dbde8b55d8bc20fb87297290a329e909 /drivers/rtc
parent05020a733b02cf7a474305e620fb306cd3abfe84 (diff)
downloadlinux-34127b3632b21e5c391756e724b1198eb9917981.tar.xz
rtc: pxa: fix null pointer dereference
With the latest stable kernel versions the rtc on the PXA based Zaurus does not work, when booting I see the following kernel messages: pxa-rtc pxa-rtc: failed to find rtc clock source pxa-rtc pxa-rtc: Unable to init SA1100 RTC sub-device pxa-rtc: probe of pxa-rtc failed with error -2 hctosys: unable to open rtc device (rtc0) I think this is because commit f2997775b111 ("rtc: sa1100: fix possible race condition") moved the allocation of the rtc_device struct out of sa1100_rtc_init and into sa1100_rtc_probe. This means that pxa_rtc_probe also needs to do allocation for the rtc_device struct, otherwise sa1100_rtc_init will try to dereference a null pointer. This patch adds that allocation by copying how sa1100_rtc_probe in drivers/rtc/rtc-sa1100.c does it; after the IRQs are set up a managed rtc_device is allocated. I've tested this patch with `qemu-system-arm -machine akita` and with a real Zaurus SL-C1000 applied to 4.19, 5.4, and 5.10. Signed-off-by: Laurence de Bruxelles <lfdebrux@gmail.com> Fixes: f2997775b111 ("rtc: sa1100: fix possible race condition") Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Link: https://lore.kernel.org/r/20220101154149.12026-1-lfdebrux@gmail.com
Diffstat (limited to 'drivers/rtc')
-rw-r--r--drivers/rtc/rtc-pxa.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-pxa.c b/drivers/rtc/rtc-pxa.c
index d2f1d8f754bf..cf8119b6d320 100644
--- a/drivers/rtc/rtc-pxa.c
+++ b/drivers/rtc/rtc-pxa.c
@@ -330,6 +330,10 @@ static int __init pxa_rtc_probe(struct platform_device *pdev)
if (sa1100_rtc->irq_alarm < 0)
return -ENXIO;
+ sa1100_rtc->rtc = devm_rtc_allocate_device(&pdev->dev);
+ if (IS_ERR(sa1100_rtc->rtc))
+ return PTR_ERR(sa1100_rtc->rtc);
+
pxa_rtc->base = devm_ioremap(dev, pxa_rtc->ress->start,
resource_size(pxa_rtc->ress));
if (!pxa_rtc->base) {