From bce7698e2e6565bb765bd0522337f29f5f312624 Mon Sep 17 00:00:00 2001 From: Haojie Li Date: Tue, 25 Aug 2026 18:08:45 +0800 Subject: drm/mediatek: Add missing IS_ERR check for ovl_adaptor platform device platform_device_register_data() can fail and return an ERR_PTR, but the return value is used without checking, leading to an invalid pointer being stored in ddp_comp[].dev and passed to component_match_add() and mtk_ddp_comp_init(), which could result in a kernel crash. Add an IS_ERR() check to jump to the error handling path on failure. Fixes: 0d9eee9118b7 ("drm/mediatek: Add drm ovl_adaptor sub driver for MT8195") Cc: stable@vger.kernel.org Signed-off-by: Haojie Li Reviewed-by: CK Hu Link: https://patchwork.kernel.org/project/linux-mediatek/patch/20260825100845.438893-1-lihaojie@kylinos.cn/ Signed-off-by: Chun-Kuang Hu --- drivers/rtc/rtc-sun4v.c | 98 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 98 insertions(+) create mode 100644 drivers/rtc/rtc-sun4v.c (limited to 'drivers/rtc/rtc-sun4v.c') diff --git a/drivers/rtc/rtc-sun4v.c b/drivers/rtc/rtc-sun4v.c new file mode 100644 index 000000000..a86e27de8 --- /dev/null +++ b/drivers/rtc/rtc-sun4v.c @@ -0,0 +1,98 @@ +// SPDX-License-Identifier: GPL-2.0 +/* rtc-sun4v.c: Hypervisor based RTC for SUN4V systems. + * + * Author: David S. Miller + * + * Copyright (C) 2008 David S. Miller + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include +#include +#include +#include +#include + +#include + +static unsigned long hypervisor_get_time(void) +{ + unsigned long ret, time; + int retries = 10000; + +retry: + ret = sun4v_tod_get(&time); + if (ret == HV_EOK) + return time; + if (ret == HV_EWOULDBLOCK) { + if (--retries > 0) { + udelay(100); + goto retry; + } + pr_warn("tod_get() timed out.\n"); + return 0; + } + pr_warn("tod_get() not supported.\n"); + return 0; +} + +static int sun4v_read_time(struct device *dev, struct rtc_time *tm) +{ + rtc_time64_to_tm(hypervisor_get_time(), tm); + return 0; +} + +static int hypervisor_set_time(unsigned long secs) +{ + unsigned long ret; + int retries = 10000; + +retry: + ret = sun4v_tod_set(secs); + if (ret == HV_EOK) + return 0; + if (ret == HV_EWOULDBLOCK) { + if (--retries > 0) { + udelay(100); + goto retry; + } + pr_warn("tod_set() timed out.\n"); + return -EAGAIN; + } + pr_warn("tod_set() not supported.\n"); + return -EOPNOTSUPP; +} + +static int sun4v_set_time(struct device *dev, struct rtc_time *tm) +{ + return hypervisor_set_time(rtc_tm_to_time64(tm)); +} + +static const struct rtc_class_ops sun4v_rtc_ops = { + .read_time = sun4v_read_time, + .set_time = sun4v_set_time, +}; + +static int __init sun4v_rtc_probe(struct platform_device *pdev) +{ + struct rtc_device *rtc; + + rtc = devm_rtc_allocate_device(&pdev->dev); + if (IS_ERR(rtc)) + return PTR_ERR(rtc); + + rtc->ops = &sun4v_rtc_ops; + rtc->range_max = U64_MAX; + platform_set_drvdata(pdev, rtc); + + return devm_rtc_register_device(rtc); +} + +static struct platform_driver sun4v_rtc_driver = { + .driver = { + .name = "rtc-sun4v", + }, +}; + +builtin_platform_driver_probe(sun4v_rtc_driver, sun4v_rtc_probe); -- cgit v1.3.1