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authorLaurence de Bruxelles <lfdebrux@gmail.com>2022-01-01 15:41:49 +0000
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2022-01-27 09:19:53 +0100
commit967ec4b059180679c392dc4a384df11214cb950e (patch)
tree00e530d72d1450823b8b77de83ee6c2f66006837 /drivers/rtc/rtc-pxa.c
parent1623e00e407c4d85d72c9c9acfc0c0e4c76595c6 (diff)
rtc: pxa: fix null pointer dereference
commit 34127b3632b21e5c391756e724b1198eb9917981 upstream. 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 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/rtc/rtc-pxa.c')
-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) {