From 00c33482bb6110bce8110daa351f9b3baf4df7dc Mon Sep 17 00:00:00 2001 From: Nikita Shubin Date: Tue, 1 Dec 2020 12:55:07 +0300 Subject: [PATCH] rtc: ep93xx: Fix NULL pointer dereference in ep93xx_rtc_read_time Mismatch in probe platform_set_drvdata set's and method's that call dev_get_platdata will result in "Unable to handle kernel NULL pointer dereference", let's use according method for getting driver data after platform_set_drvdata. 8<--- cut here --- Unable to handle kernel NULL pointer dereference at virtual address 00000000 pgd = (ptrval) [00000000] *pgd=00000000 Internal error: Oops: 5 [#1] ARM Modules linked in: CPU: 0 PID: 1 Comm: swapper Not tainted 5.9.10-00003-g723e101e0037-dirty #4 Hardware name: Technologic Systems TS-72xx SBC PC is at ep93xx_rtc_read_time+0xc/0x2c LR is at __rtc_read_time+0x4c/0x8c [...] [] (ep93xx_rtc_read_time) from [] (__rtc_read_time+0x4c/0x8c) [] (__rtc_read_time) from [] (rtc_read_time+0x2c/0x4c) [] (rtc_read_time) from [] (__rtc_read_alarm+0x28/0x358) [] (__rtc_read_alarm) from [] (__rtc_register_device+0x124/0x2ec) [] (__rtc_register_device) from [] (ep93xx_rtc_probe+0xa4/0xac) [] (ep93xx_rtc_probe) from [] (platform_drv_probe+0x24/0x5c) [] (platform_drv_probe) from [] (really_probe+0x218/0x374) [] (really_probe) from [] (device_driver_attach+0x44/0x60) [] (device_driver_attach) from [] (__driver_attach+0xb4/0xc0) [] (__driver_attach) from [] (bus_for_each_dev+0x68/0xac) [] (bus_for_each_dev) from [] (driver_attach+0x18/0x24) [] (driver_attach) from [] (bus_add_driver+0x150/0x1b4) [] (bus_add_driver) from [] (driver_register+0xb0/0xf4) [] (driver_register) from [] (__platform_driver_register+0x30/0x48) [] (__platform_driver_register) from [] (ep93xx_rtc_driver_init+0x10/0x1c) [] (ep93xx_rtc_driver_init) from [] (do_one_initcall+0x7c/0x1c0) [] (do_one_initcall) from [] (kernel_init_freeable+0x168/0x1ac) [] (kernel_init_freeable) from [] (kernel_init+0x8/0xf4) [] (kernel_init) from [] (ret_from_fork+0x14/0x34) Exception stack(0xc441dfb0 to 0xc441dff8) dfa0: 00000000 00000000 00000000 00000000 dfc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 dfe0: 00000000 00000000 00000000 00000000 00000013 00000000 Code: e12fff1e e92d4010 e590303c e1a02001 (e5933000) ---[ end trace c914d6030eaa95c8 ]--- Fixes: b809d192eb98 ("rtc: ep93xx: stop setting platform_data") Signed-off-by: Nikita Shubin Signed-off-by: Alexandre Belloni Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20201201095507.10317-1-nikita.shubin@maquefel.me --- drivers/rtc/rtc-ep93xx.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/rtc/rtc-ep93xx.c b/drivers/rtc/rtc-ep93xx.c index 9a5a15cbcd9b..acae7f16808f 100644 --- a/drivers/rtc/rtc-ep93xx.c +++ b/drivers/rtc/rtc-ep93xx.c @@ -33,7 +33,7 @@ struct ep93xx_rtc { static int ep93xx_rtc_get_swcomp(struct device *dev, unsigned short *preload, unsigned short *delete) { - struct ep93xx_rtc *ep93xx_rtc = dev_get_platdata(dev); + struct ep93xx_rtc *ep93xx_rtc = dev_get_drvdata(dev); unsigned long comp; comp = readl(ep93xx_rtc->mmio_base + EP93XX_RTC_SWCOMP); @@ -51,7 +51,7 @@ static int ep93xx_rtc_get_swcomp(struct device *dev, unsigned short *preload, static int ep93xx_rtc_read_time(struct device *dev, struct rtc_time *tm) { - struct ep93xx_rtc *ep93xx_rtc = dev_get_platdata(dev); + struct ep93xx_rtc *ep93xx_rtc = dev_get_drvdata(dev); unsigned long time; time = readl(ep93xx_rtc->mmio_base + EP93XX_RTC_DATA); @@ -62,7 +62,7 @@ static int ep93xx_rtc_read_time(struct device *dev, struct rtc_time *tm) static int ep93xx_rtc_set_time(struct device *dev, struct rtc_time *tm) { - struct ep93xx_rtc *ep93xx_rtc = dev_get_platdata(dev); + struct ep93xx_rtc *ep93xx_rtc = dev_get_drvdata(dev); unsigned long secs = rtc_tm_to_time64(tm); writel(secs + 1, ep93xx_rtc->mmio_base + EP93XX_RTC_LOAD);