From 034dd340b08be1f2f0477ad16131d609f9dbd53c Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sun, 30 Aug 2026 09:22:00 -0700 Subject: Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull tracing fixes from Steven Rostedt: - Fix error output of boot instance creation failure Currently if a boot instance creation fails, instead of printing out the name of the instance that failed, it prints "(null)". That is because it prints "cur_str" that had already been processed by strsep(). Print the saved name instead. While at it, print the error code of the failure. - Fix use-after-free for same named historgrams Histograms can be named so that they can be used in multiple events. But if the named histogram has a variable attached, the second event that uses the named histogram which duplicates it and needs to free the original after duplication leaves the old variable in place and still visible. If another histogram uses than variable, it will use the stale one which will try to reference the freed duplicate histogram and crash the kernel. Free the duplicate variables along with the duplicated histogram data. - Check return value of kthread_run() in event self test The events self tests uses a kthread for testing but does not check if it succeeded in creating a kthread. If the kthread creation were to fail, the code will still try to call kthread_stop() on the error returned. - Fix race between reading trace_pipe and updating subbuffer size If a user is reading the trace_pipe file at the same time they update the ring buffer sub-buffer size, can cause the trace_pipe read to read stale data. Add trace_access_lock() around updating the ring buffer sub-buffer size. - Fix eventfs_inode on failure path in creation of the events directory In the creation of the "events" directory, if after allocating the eventfs_inode a failure is detected, it calls cleanup_ei() which calls free_ei(). The free_ei() will test if eventfs_inode being freed has no children. It is a bug if it does. But on the failure case of the creation of the "events" directory, the children lists have not yet been initialized and the free will trigger a warning because list_empty() on an uninitialized list returns false. Move the initialization into init_ei() where it makes more sense and makes sure that a created eventfs_inode has its lists initialized upon creation. - Check return value of kthread_run() in ftrace direct sample code The sample code that shows how to use the ftrace direct calls does not test the return of kthread_run() to see if it succeeds. Return a failure if the kthread_run() doesn't succeed. - Clear user events state on fork in case of alloc failure On fork, the child gets a pointer to the parent's user events state. It makes a copy of it then updates the child's pointer to it. But if the allocation fails, the duplication function leaves the child with a pointer to its parent's descriptor. When the child cleans up its data, it will free the parent's descriptor while the parent is still using it. In the duplication function, set the child's user_event_mm to NULL before testing if the allocation succeeded, and when it exits it will not free the parent's descriptor. - Fix retry exhaustion in simple ring buffer reader swap simple_ring_buffer_swap_reader_page() starts with retry set to 8 and post-decrements it only after a failed link replacement. On the final attempt, a successful replacement leaves retry at zero, while a failed replacement leaves it at -1. But the check for success expects the retry value to be non-zero and exits with an error on zero. This is the opposite result. Fix it. - Fail nicely when the remote swap_reader_page() returns an error Currently, if the swap_reader_page() of a remote buffer fails, it triggers a WARN_ON_ONCE() and continues normally. Instead, have it exit with an error and a pr_warn() print instead of a full WARNING. * tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: ring-buffer: Stop remote reader update when page swap fails tracing: Fix retry exhaustion in simple ring buffer reader swap tracing/user_events: Clear copied tracing state before fork duplication samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify eventfs: Initialize ei->children and ei->list in init_ei() tracing: Fix use-after-free in trace_pipe read on sub-buffer order change tracing: Fix crash passing ERR_PTR to kthread_stop() tracing: Fix use-after-free with same-name named triggers tracing: Fix logged instance name on creation failure --- drivers/rtc/rtc-sd3078.c | 213 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 213 insertions(+) create mode 100644 drivers/rtc/rtc-sd3078.c (limited to 'drivers/rtc/rtc-sd3078.c') diff --git a/drivers/rtc/rtc-sd3078.c b/drivers/rtc/rtc-sd3078.c new file mode 100644 index 000000000..2c61f0e20 --- /dev/null +++ b/drivers/rtc/rtc-sd3078.c @@ -0,0 +1,213 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Real Time Clock (RTC) Driver for sd3078 + * Copyright (C) 2018 Zoro Li + */ + +#include +#include +#include +#include +#include +#include + +#define SD3078_REG_SC 0x00 +#define SD3078_REG_MN 0x01 +#define SD3078_REG_HR 0x02 +#define SD3078_REG_DW 0x03 +#define SD3078_REG_DM 0x04 +#define SD3078_REG_MO 0x05 +#define SD3078_REG_YR 0x06 + +#define SD3078_REG_CTRL1 0x0f +#define SD3078_REG_CTRL2 0x10 +#define SD3078_REG_CTRL3 0x11 + +#define KEY_WRITE1 0x80 +#define KEY_WRITE2 0x04 +#define KEY_WRITE3 0x80 + +#define NUM_TIME_REGS (SD3078_REG_YR - SD3078_REG_SC + 1) + +/* + * The sd3078 has write protection + * and we can choose whether or not to use it. + * Write protection is turned off by default. + */ +#define WRITE_PROTECT_EN 0 + +/* + * In order to prevent arbitrary modification of the time register, + * when modification of the register, + * the "write" bit needs to be written in a certain order. + * 1. set WRITE1 bit + * 2. set WRITE2 bit + * 3. set WRITE3 bit + */ +static void sd3078_enable_reg_write(struct regmap *regmap) +{ + regmap_update_bits(regmap, SD3078_REG_CTRL2, KEY_WRITE1, KEY_WRITE1); + regmap_update_bits(regmap, SD3078_REG_CTRL1, KEY_WRITE2, KEY_WRITE2); + regmap_update_bits(regmap, SD3078_REG_CTRL1, KEY_WRITE3, KEY_WRITE3); +} + +#if WRITE_PROTECT_EN +/* + * In order to prevent arbitrary modification of the time register, + * we should disable the write function. + * when disable write, + * the "write" bit needs to be clear in a certain order. + * 1. clear WRITE2 bit + * 2. clear WRITE3 bit + * 3. clear WRITE1 bit + */ +static void sd3078_disable_reg_write(struct regmap *regmap) +{ + regmap_update_bits(regmap, SD3078_REG_CTRL1, KEY_WRITE2, 0); + regmap_update_bits(regmap, SD3078_REG_CTRL1, KEY_WRITE3, 0); + regmap_update_bits(regmap, SD3078_REG_CTRL2, KEY_WRITE1, 0); +} +#endif + +static int sd3078_rtc_read_time(struct device *dev, struct rtc_time *tm) +{ + unsigned char hour; + unsigned char rtc_data[NUM_TIME_REGS] = {0}; + struct i2c_client *client = to_i2c_client(dev); + struct regmap *regmap = i2c_get_clientdata(client); + int ret; + + ret = regmap_bulk_read(regmap, SD3078_REG_SC, rtc_data, NUM_TIME_REGS); + if (ret < 0) { + dev_err(dev, "reading from RTC failed with err:%d\n", ret); + return ret; + } + + tm->tm_sec = bcd2bin(rtc_data[SD3078_REG_SC] & 0x7F); + tm->tm_min = bcd2bin(rtc_data[SD3078_REG_MN] & 0x7F); + + /* + * The sd3078 supports 12/24 hour mode. + * When getting time, + * we need to convert the 12 hour mode to the 24 hour mode. + */ + hour = rtc_data[SD3078_REG_HR]; + if (hour & 0x80) /* 24H MODE */ + tm->tm_hour = bcd2bin(rtc_data[SD3078_REG_HR] & 0x3F); + else if (hour & 0x20) /* 12H MODE PM */ + tm->tm_hour = bcd2bin(rtc_data[SD3078_REG_HR] & 0x1F) + 12; + else /* 12H MODE AM */ + tm->tm_hour = bcd2bin(rtc_data[SD3078_REG_HR] & 0x1F); + + tm->tm_mday = bcd2bin(rtc_data[SD3078_REG_DM] & 0x3F); + tm->tm_wday = rtc_data[SD3078_REG_DW] & 0x07; + tm->tm_mon = bcd2bin(rtc_data[SD3078_REG_MO] & 0x1F) - 1; + tm->tm_year = bcd2bin(rtc_data[SD3078_REG_YR]) + 100; + + return 0; +} + +static int sd3078_rtc_set_time(struct device *dev, struct rtc_time *tm) +{ + unsigned char rtc_data[NUM_TIME_REGS]; + struct i2c_client *client = to_i2c_client(dev); + struct regmap *regmap = i2c_get_clientdata(client); + int ret; + + rtc_data[SD3078_REG_SC] = bin2bcd(tm->tm_sec); + rtc_data[SD3078_REG_MN] = bin2bcd(tm->tm_min); + rtc_data[SD3078_REG_HR] = bin2bcd(tm->tm_hour) | 0x80; + rtc_data[SD3078_REG_DM] = bin2bcd(tm->tm_mday); + rtc_data[SD3078_REG_DW] = tm->tm_wday & 0x07; + rtc_data[SD3078_REG_MO] = bin2bcd(tm->tm_mon) + 1; + rtc_data[SD3078_REG_YR] = bin2bcd(tm->tm_year - 100); + +#if WRITE_PROTECT_EN + sd3078_enable_reg_write(regmap); +#endif + + ret = regmap_bulk_write(regmap, SD3078_REG_SC, rtc_data, + NUM_TIME_REGS); + if (ret < 0) { + dev_err(dev, "writing to RTC failed with err:%d\n", ret); + return ret; + } + +#if WRITE_PROTECT_EN + sd3078_disable_reg_write(regmap); +#endif + + return 0; +} + +static const struct rtc_class_ops sd3078_rtc_ops = { + .read_time = sd3078_rtc_read_time, + .set_time = sd3078_rtc_set_time, +}; + +static const struct regmap_config regmap_config = { + .reg_bits = 8, + .val_bits = 8, + .max_register = 0x11, +}; + +static int sd3078_probe(struct i2c_client *client) +{ + int ret; + struct regmap *regmap; + struct rtc_device *rtc; + + if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) + return -ENODEV; + + regmap = devm_regmap_init_i2c(client, ®map_config); + if (IS_ERR(regmap)) { + dev_err(&client->dev, "regmap allocation failed\n"); + return PTR_ERR(regmap); + } + + i2c_set_clientdata(client, regmap); + + rtc = devm_rtc_allocate_device(&client->dev); + if (IS_ERR(rtc)) + return PTR_ERR(rtc); + + rtc->ops = &sd3078_rtc_ops; + rtc->range_min = RTC_TIMESTAMP_BEGIN_2000; + rtc->range_max = RTC_TIMESTAMP_END_2099; + + ret = devm_rtc_register_device(rtc); + if (ret) + return ret; + + sd3078_enable_reg_write(regmap); + + return 0; +} + +static const struct i2c_device_id sd3078_id[] = { + { .name = "sd3078" }, + { } +}; +MODULE_DEVICE_TABLE(i2c, sd3078_id); + +static const __maybe_unused struct of_device_id rtc_dt_match[] = { + { .compatible = "whwave,sd3078" }, + {}, +}; +MODULE_DEVICE_TABLE(of, rtc_dt_match); + +static struct i2c_driver sd3078_driver = { + .driver = { + .name = "sd3078", + .of_match_table = of_match_ptr(rtc_dt_match), + }, + .probe = sd3078_probe, + .id_table = sd3078_id, +}; + +module_i2c_driver(sd3078_driver); + +MODULE_AUTHOR("Dianlong Li "); +MODULE_DESCRIPTION("SD3078 RTC driver"); +MODULE_LICENSE("GPL v2"); -- cgit v1.3.1