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author | Julien Folly <julien.folly@gmail.com> | 2018-10-09 19:47:45 +0200 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-12-01 09:16:22 +0100 |
commit | 4ab1594e699ed2371e7ea9e6893b58e4038a40fc (patch) | |
tree | 97374ba99349d92fde7da6b66e341cadfaf60f61 /drivers/w1 | |
parent | d11d985d0a8285cc308a61c2464ad68e8e1f4ff8 (diff) | |
download | linux-stable-4ab1594e699ed2371e7ea9e6893b58e4038a40fc.tar.gz linux-stable-4ab1594e699ed2371e7ea9e6893b58e4038a40fc.tar.bz2 linux-stable-4ab1594e699ed2371e7ea9e6893b58e4038a40fc.zip |
w1: IAD Register is yet readable trough iad sys file. Fix snprintf (%u for unsigned, count for max size).
[ Upstream commit 6eaafbb6998e999467cf78a76e155ee00e372b14 ]
IAD Register is yet readable trough the "iad" sys file.
A write to the "iad" sys file enables or disables the current
measurement, but it was not possible to get the measured value by
reading it.
Fix: %u in snprintf for unsigned values (vdd and vad)
Fix: Avoid possibles overflows (Usage of the 'count' variables)
Signed-off-by: Julien Folly <julien.folly@gmail.com>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'drivers/w1')
-rw-r--r-- | drivers/w1/slaves/w1_ds2438.c | 66 |
1 files changed, 52 insertions, 14 deletions
diff --git a/drivers/w1/slaves/w1_ds2438.c b/drivers/w1/slaves/w1_ds2438.c index bf641a191d07..7c4e33dbee4d 100644 --- a/drivers/w1/slaves/w1_ds2438.c +++ b/drivers/w1/slaves/w1_ds2438.c @@ -186,8 +186,8 @@ static int w1_ds2438_change_config_bit(struct w1_slave *sl, u8 mask, u8 value) return -1; } -static uint16_t w1_ds2438_get_voltage(struct w1_slave *sl, - int adc_input, uint16_t *voltage) +static int w1_ds2438_get_voltage(struct w1_slave *sl, + int adc_input, uint16_t *voltage) { unsigned int retries = W1_DS2438_RETRIES; u8 w1_buf[DS2438_PAGE_SIZE + 1 /*for CRC*/]; @@ -235,6 +235,25 @@ post_unlock: return ret; } +static int w1_ds2438_get_current(struct w1_slave *sl, int16_t *voltage) +{ + u8 w1_buf[DS2438_PAGE_SIZE + 1 /*for CRC*/]; + int ret; + + mutex_lock(&sl->master->bus_mutex); + + if (w1_ds2438_get_page(sl, 0, w1_buf) == 0) { + /* The voltage measured across current sense resistor RSENS. */ + *voltage = (((int16_t) w1_buf[DS2438_CURRENT_MSB]) << 8) | ((int16_t) w1_buf[DS2438_CURRENT_LSB]); + ret = 0; + } else + ret = -1; + + mutex_unlock(&sl->master->bus_mutex); + + return ret; +} + static ssize_t iad_write(struct file *filp, struct kobject *kobj, struct bin_attribute *bin_attr, char *buf, loff_t off, size_t count) @@ -257,6 +276,27 @@ static ssize_t iad_write(struct file *filp, struct kobject *kobj, return ret; } +static ssize_t iad_read(struct file *filp, struct kobject *kobj, + struct bin_attribute *bin_attr, char *buf, + loff_t off, size_t count) +{ + struct w1_slave *sl = kobj_to_w1_slave(kobj); + int ret; + int16_t voltage; + + if (off != 0) + return 0; + if (!buf) + return -EINVAL; + + if (w1_ds2438_get_current(sl, &voltage) == 0) { + ret = snprintf(buf, count, "%i\n", voltage); + } else + ret = -EIO; + + return ret; +} + static ssize_t page0_read(struct file *filp, struct kobject *kobj, struct bin_attribute *bin_attr, char *buf, loff_t off, size_t count) @@ -272,9 +312,13 @@ static ssize_t page0_read(struct file *filp, struct kobject *kobj, mutex_lock(&sl->master->bus_mutex); + /* Read no more than page0 size */ + if (count > DS2438_PAGE_SIZE) + count = DS2438_PAGE_SIZE; + if (w1_ds2438_get_page(sl, 0, w1_buf) == 0) { - memcpy(buf, &w1_buf, DS2438_PAGE_SIZE); - ret = DS2438_PAGE_SIZE; + memcpy(buf, &w1_buf, count); + ret = count; } else ret = -EIO; @@ -289,7 +333,6 @@ static ssize_t temperature_read(struct file *filp, struct kobject *kobj, { struct w1_slave *sl = kobj_to_w1_slave(kobj); int ret; - ssize_t c = PAGE_SIZE; int16_t temp; if (off != 0) @@ -298,8 +341,7 @@ static ssize_t temperature_read(struct file *filp, struct kobject *kobj, return -EINVAL; if (w1_ds2438_get_temperature(sl, &temp) == 0) { - c -= snprintf(buf + PAGE_SIZE - c, c, "%d\n", temp); - ret = PAGE_SIZE - c; + ret = snprintf(buf, count, "%i\n", temp); } else ret = -EIO; @@ -312,7 +354,6 @@ static ssize_t vad_read(struct file *filp, struct kobject *kobj, { struct w1_slave *sl = kobj_to_w1_slave(kobj); int ret; - ssize_t c = PAGE_SIZE; uint16_t voltage; if (off != 0) @@ -321,8 +362,7 @@ static ssize_t vad_read(struct file *filp, struct kobject *kobj, return -EINVAL; if (w1_ds2438_get_voltage(sl, DS2438_ADC_INPUT_VAD, &voltage) == 0) { - c -= snprintf(buf + PAGE_SIZE - c, c, "%d\n", voltage); - ret = PAGE_SIZE - c; + ret = snprintf(buf, count, "%u\n", voltage); } else ret = -EIO; @@ -335,7 +375,6 @@ static ssize_t vdd_read(struct file *filp, struct kobject *kobj, { struct w1_slave *sl = kobj_to_w1_slave(kobj); int ret; - ssize_t c = PAGE_SIZE; uint16_t voltage; if (off != 0) @@ -344,15 +383,14 @@ static ssize_t vdd_read(struct file *filp, struct kobject *kobj, return -EINVAL; if (w1_ds2438_get_voltage(sl, DS2438_ADC_INPUT_VDD, &voltage) == 0) { - c -= snprintf(buf + PAGE_SIZE - c, c, "%d\n", voltage); - ret = PAGE_SIZE - c; + ret = snprintf(buf, count, "%u\n", voltage); } else ret = -EIO; return ret; } -static BIN_ATTR(iad, S_IRUGO | S_IWUSR | S_IWGRP, NULL, iad_write, 1); +static BIN_ATTR(iad, S_IRUGO | S_IWUSR | S_IWGRP, iad_read, iad_write, 0); static BIN_ATTR_RO(page0, DS2438_PAGE_SIZE); static BIN_ATTR_RO(temperature, 0/* real length varies */); static BIN_ATTR_RO(vad, 0/* real length varies */); |