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 --- samples/user_events/example.c | 73 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 73 insertions(+) create mode 100644 samples/user_events/example.c (limited to 'samples/user_events/example.c') diff --git a/samples/user_events/example.c b/samples/user_events/example.c new file mode 100644 index 000000000..28165a096 --- /dev/null +++ b/samples/user_events/example.c @@ -0,0 +1,73 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (c) 2021, Microsoft Corporation. + * + * Authors: + * Beau Belgrave + */ + +#include +#include +#include +#include +#include +#include +#include +#include + +const char *data_file = "/sys/kernel/tracing/user_events_data"; +int enabled = 0; + +static int event_reg(int fd, const char *command, int *write, int *enabled) +{ + struct user_reg reg = {0}; + + reg.size = sizeof(reg); + reg.enable_bit = 31; + reg.enable_size = sizeof(*enabled); + reg.enable_addr = (__u64)enabled; + reg.name_args = (__u64)command; + + if (ioctl(fd, DIAG_IOCSREG, ®) == -1) + return -1; + + *write = reg.write_index; + + return 0; +} + +int main(int argc, char **argv) +{ + int data_fd, write; + struct iovec io[2]; + __u32 count = 0; + + data_fd = open(data_file, O_RDWR); + + if (event_reg(data_fd, "test u32 count", &write, &enabled) == -1) + return errno; + + /* Setup iovec */ + io[0].iov_base = &write; + io[0].iov_len = sizeof(write); + io[1].iov_base = &count; + io[1].iov_len = sizeof(count); +ask: + printf("Press enter to check status...\n"); + getchar(); + + /* Check if anyone is listening */ + if (enabled) { + /* Yep, trace out our data */ + writev(data_fd, (const struct iovec *)io, 2); + + /* Increase the count */ + count++; + + printf("Something was attached, wrote data\n"); + } + + goto ask; + + return 0; +} -- cgit v1.3.1