May 2024 - Linux-stable-mirror

FAILED: patch "[PATCH] Input: try trimming too long modalias strings" failed to apply to 5.4-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.4.y git checkout FETCH_HEAD git cherry-pick -x 0774d19038c496f0c3602fb505c43e1b2d8eed85 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024052512-grunt-open-ce9d@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 0774d19038c496f0c3602fb505c43e1b2d8eed85 Mon Sep 17 00:00:00 2001 From: Dmitry Torokhov <dmitry.torokhov(a)gmail.com> Date: Mon, 29 Apr 2024 14:50:41 -0700 Subject: [PATCH] Input: try trimming too long modalias strings If an input device declares too many capability bits then modalias string for such device may become too long and not fit into uevent buffer, resulting in failure of sending said uevent. This, in turn, may prevent userspace from recognizing existence of such devices. This is typically not a concern for real hardware devices as they have limited number of keys, but happen with synthetic devices such as ones created by xen-kbdfront driver, which creates devices as being capable of delivering all possible keys, since it doesn't know what keys the backend may produce. To deal with such devices input core will attempt to trim key data, in the hope that the rest of modalias string will fit in the given buffer. When trimming key data it will indicate that it is not complete by placing "+," sign, resulting in conversions like this: old: k71,72,73,74,78,7A,7B,7C,7D,8E,9E,A4,AD,E0,E1,E4,F8,174, new: k71,72,73,74,78,7A,7B,7C,+, This should allow existing udev rules continue to work with existing devices, and will also allow writing more complex rules that would recognize trimmed modalias and check input device characteristics by other means (for example by parsing KEY= data in uevent or parsing input device sysfs attributes). Note that the driver core may try adding more uevent environment variables once input core is done adding its own, so when forming modalias we can not use the entire available buffer, so we reduce it by somewhat an arbitrary amount (96 bytes). Reported-by: Jason Andryuk <jandryuk(a)gmail.com> Reviewed-by: Peter Hutterer <peter.hutterer(a)who-t.net> Tested-by: Jason Andryuk <jandryuk(a)gmail.com> Link: https://lore.kernel.org/r/ZjAWMQCJdrxZkvkB@google.com Cc: stable(a)vger.kernel.org Signed-off-by: Dmitry Torokhov <dmitry.torokhov(a)gmail.com> diff --git a/drivers/input/input.c b/drivers/input/input.c index 711485437567..fd4997ba263c 100644 --- a/drivers/input/input.c +++ b/drivers/input/input.c @@ -1378,19 +1378,19 @@ static int input_print_modalias_bits(char *buf, int size, char name, const unsigned long *bm, unsigned int min_bit, unsigned int max_bit) { - int len = 0, i; + int bit = min_bit; + int len = 0; len += snprintf(buf, max(size, 0), "%c", name); - for (i = min_bit; i < max_bit; i++) - if (bm[BIT_WORD(i)] & BIT_MASK(i)) - len += snprintf(buf + len, max(size - len, 0), "%X,", i); + for_each_set_bit_from(bit, bm, max_bit) + len += snprintf(buf + len, max(size - len, 0), "%X,", bit); return len; } -static int input_print_modalias(char *buf, int size, const struct input_dev *id, - int add_cr) +static int input_print_modalias_parts(char *buf, int size, int full_len, + const struct input_dev *id) { - int len; + int len, klen, remainder, space; len = snprintf(buf, max(size, 0), "input:b%04Xv%04Xp%04Xe%04X-", @@ -1399,8 +1399,48 @@ static int input_print_modalias(char *buf, int size, const struct input_dev *id, len += input_print_modalias_bits(buf + len, size - len, 'e', id->evbit, 0, EV_MAX); - len += input_print_modalias_bits(buf + len, size - len, + + /* + * Calculate the remaining space in the buffer making sure we + * have place for the terminating 0. + */ + space = max(size - (len + 1), 0); + + klen = input_print_modalias_bits(buf + len, size - len, 'k', id->keybit, KEY_MIN_INTERESTING, KEY_MAX); + len += klen; + + /* + * If we have more data than we can fit in the buffer, check + * if we can trim key data to fit in the rest. We will indicate + * that key data is incomplete by adding "+" sign at the end, like + * this: * "k1,2,3,45,+,". + * + * Note that we shortest key info (if present) is "k+," so we + * can only try to trim if key data is longer than that. + */ + if (full_len && size < full_len + 1 && klen > 3) { + remainder = full_len - len; + /* + * We can only trim if we have space for the remainder + * and also for at least "k+," which is 3 more characters. + */ + if (remainder <= space - 3) { + /* + * We are guaranteed to have 'k' in the buffer, so + * we need at least 3 additional bytes for storing + * "+," in addition to the remainder. + */ + for (int i = size - 1 - remainder - 3; i >= 0; i--) { + if (buf[i] == 'k' || buf[i] == ',') { + strcpy(buf + i + 1, "+,"); + len = i + 3; /* Not counting '\0' */ + break; + } + } + } + } + len += input_print_modalias_bits(buf + len, size - len, 'r', id->relbit, 0, REL_MAX); len += input_print_modalias_bits(buf + len, size - len, @@ -1416,12 +1456,25 @@ static int input_print_modalias(char *buf, int size, const struct input_dev *id, len += input_print_modalias_bits(buf + len, size - len, 'w', id->swbit, 0, SW_MAX); - if (add_cr) - len += snprintf(buf + len, max(size - len, 0), "\n"); - return len; } +static int input_print_modalias(char *buf, int size, const struct input_dev *id) +{ + int full_len; + + /* + * Printing is done in 2 passes: first one figures out total length + * needed for the modalias string, second one will try to trim key + * data in case when buffer is too small for the entire modalias. + * If the buffer is too small regardless, it will fill as much as it + * can (without trimming key data) into the buffer and leave it to + * the caller to figure out what to do with the result. + */ + full_len = input_print_modalias_parts(NULL, 0, 0, id); + return input_print_modalias_parts(buf, size, full_len, id); +} + static ssize_t input_dev_show_modalias(struct device *dev, struct device_attribute *attr, char *buf) @@ -1429,7 +1482,9 @@ static ssize_t input_dev_show_modalias(struct device *dev, struct input_dev *id = to_input_dev(dev); ssize_t len; - len = input_print_modalias(buf, PAGE_SIZE, id, 1); + len = input_print_modalias(buf, PAGE_SIZE, id); + if (len < PAGE_SIZE - 2) + len += snprintf(buf + len, PAGE_SIZE - len, "\n"); return min_t(int, len, PAGE_SIZE); } @@ -1641,6 +1696,23 @@ static int input_add_uevent_bm_var(struct kobj_uevent_env *env, return 0; } +/* + * This is a pretty gross hack. When building uevent data the driver core + * may try adding more environment variables to kobj_uevent_env without + * telling us, so we have no idea how much of the buffer we can use to + * avoid overflows/-ENOMEM elsewhere. To work around this let's artificially + * reduce amount of memory we will use for the modalias environment variable. + * + * The potential additions are: + * + * SEQNUM=18446744073709551615 - (%llu - 28 bytes) + * HOME=/ (6 bytes) + * PATH=/sbin:/bin:/usr/sbin:/usr/bin (34 bytes) + * + * 68 bytes total. Allow extra buffer - 96 bytes + */ +#define UEVENT_ENV_EXTRA_LEN 96 + static int input_add_uevent_modalias_var(struct kobj_uevent_env *env, const struct input_dev *dev) { @@ -1650,9 +1722,11 @@ static int input_add_uevent_modalias_var(struct kobj_uevent_env *env, return -ENOMEM; len = input_print_modalias(&env->buf[env->buflen - 1], - sizeof(env->buf) - env->buflen, - dev, 0); - if (len >= (sizeof(env->buf) - env->buflen)) + (int)sizeof(env->buf) - env->buflen - + UEVENT_ENV_EXTRA_LEN, + dev); + if (len >= ((int)sizeof(env->buf) - env->buflen - + UEVENT_ENV_EXTRA_LEN)) return -ENOMEM; env->buflen += len;

7 months, 2 weeks

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FAILED: patch "[PATCH] Input: try trimming too long modalias strings" failed to apply to 5.10-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.10-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.10.y git checkout FETCH_HEAD git cherry-pick -x 0774d19038c496f0c3602fb505c43e1b2d8eed85 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024052511-greedless-jukebox-5abd@gregkh' --subject-prefix 'PATCH 5.10.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 0774d19038c496f0c3602fb505c43e1b2d8eed85 Mon Sep 17 00:00:00 2001 From: Dmitry Torokhov <dmitry.torokhov(a)gmail.com> Date: Mon, 29 Apr 2024 14:50:41 -0700 Subject: [PATCH] Input: try trimming too long modalias strings If an input device declares too many capability bits then modalias string for such device may become too long and not fit into uevent buffer, resulting in failure of sending said uevent. This, in turn, may prevent userspace from recognizing existence of such devices. This is typically not a concern for real hardware devices as they have limited number of keys, but happen with synthetic devices such as ones created by xen-kbdfront driver, which creates devices as being capable of delivering all possible keys, since it doesn't know what keys the backend may produce. To deal with such devices input core will attempt to trim key data, in the hope that the rest of modalias string will fit in the given buffer. When trimming key data it will indicate that it is not complete by placing "+," sign, resulting in conversions like this: old: k71,72,73,74,78,7A,7B,7C,7D,8E,9E,A4,AD,E0,E1,E4,F8,174, new: k71,72,73,74,78,7A,7B,7C,+, This should allow existing udev rules continue to work with existing devices, and will also allow writing more complex rules that would recognize trimmed modalias and check input device characteristics by other means (for example by parsing KEY= data in uevent or parsing input device sysfs attributes). Note that the driver core may try adding more uevent environment variables once input core is done adding its own, so when forming modalias we can not use the entire available buffer, so we reduce it by somewhat an arbitrary amount (96 bytes). Reported-by: Jason Andryuk <jandryuk(a)gmail.com> Reviewed-by: Peter Hutterer <peter.hutterer(a)who-t.net> Tested-by: Jason Andryuk <jandryuk(a)gmail.com> Link: https://lore.kernel.org/r/ZjAWMQCJdrxZkvkB@google.com Cc: stable(a)vger.kernel.org Signed-off-by: Dmitry Torokhov <dmitry.torokhov(a)gmail.com> diff --git a/drivers/input/input.c b/drivers/input/input.c index 711485437567..fd4997ba263c 100644 --- a/drivers/input/input.c +++ b/drivers/input/input.c @@ -1378,19 +1378,19 @@ static int input_print_modalias_bits(char *buf, int size, char name, const unsigned long *bm, unsigned int min_bit, unsigned int max_bit) { - int len = 0, i; + int bit = min_bit; + int len = 0; len += snprintf(buf, max(size, 0), "%c", name); - for (i = min_bit; i < max_bit; i++) - if (bm[BIT_WORD(i)] & BIT_MASK(i)) - len += snprintf(buf + len, max(size - len, 0), "%X,", i); + for_each_set_bit_from(bit, bm, max_bit) + len += snprintf(buf + len, max(size - len, 0), "%X,", bit); return len; } -static int input_print_modalias(char *buf, int size, const struct input_dev *id, - int add_cr) +static int input_print_modalias_parts(char *buf, int size, int full_len, + const struct input_dev *id) { - int len; + int len, klen, remainder, space; len = snprintf(buf, max(size, 0), "input:b%04Xv%04Xp%04Xe%04X-", @@ -1399,8 +1399,48 @@ static int input_print_modalias(char *buf, int size, const struct input_dev *id, len += input_print_modalias_bits(buf + len, size - len, 'e', id->evbit, 0, EV_MAX); - len += input_print_modalias_bits(buf + len, size - len, + + /* + * Calculate the remaining space in the buffer making sure we + * have place for the terminating 0. + */ + space = max(size - (len + 1), 0); + + klen = input_print_modalias_bits(buf + len, size - len, 'k', id->keybit, KEY_MIN_INTERESTING, KEY_MAX); + len += klen; + + /* + * If we have more data than we can fit in the buffer, check + * if we can trim key data to fit in the rest. We will indicate + * that key data is incomplete by adding "+" sign at the end, like + * this: * "k1,2,3,45,+,". + * + * Note that we shortest key info (if present) is "k+," so we + * can only try to trim if key data is longer than that. + */ + if (full_len && size < full_len + 1 && klen > 3) { + remainder = full_len - len; + /* + * We can only trim if we have space for the remainder + * and also for at least "k+," which is 3 more characters. + */ + if (remainder <= space - 3) { + /* + * We are guaranteed to have 'k' in the buffer, so + * we need at least 3 additional bytes for storing + * "+," in addition to the remainder. + */ + for (int i = size - 1 - remainder - 3; i >= 0; i--) { + if (buf[i] == 'k' || buf[i] == ',') { + strcpy(buf + i + 1, "+,"); + len = i + 3; /* Not counting '\0' */ + break; + } + } + } + } + len += input_print_modalias_bits(buf + len, size - len, 'r', id->relbit, 0, REL_MAX); len += input_print_modalias_bits(buf + len, size - len, @@ -1416,12 +1456,25 @@ static int input_print_modalias(char *buf, int size, const struct input_dev *id, len += input_print_modalias_bits(buf + len, size - len, 'w', id->swbit, 0, SW_MAX); - if (add_cr) - len += snprintf(buf + len, max(size - len, 0), "\n"); - return len; } +static int input_print_modalias(char *buf, int size, const struct input_dev *id) +{ + int full_len; + + /* + * Printing is done in 2 passes: first one figures out total length + * needed for the modalias string, second one will try to trim key + * data in case when buffer is too small for the entire modalias. + * If the buffer is too small regardless, it will fill as much as it + * can (without trimming key data) into the buffer and leave it to + * the caller to figure out what to do with the result. + */ + full_len = input_print_modalias_parts(NULL, 0, 0, id); + return input_print_modalias_parts(buf, size, full_len, id); +} + static ssize_t input_dev_show_modalias(struct device *dev, struct device_attribute *attr, char *buf) @@ -1429,7 +1482,9 @@ static ssize_t input_dev_show_modalias(struct device *dev, struct input_dev *id = to_input_dev(dev); ssize_t len; - len = input_print_modalias(buf, PAGE_SIZE, id, 1); + len = input_print_modalias(buf, PAGE_SIZE, id); + if (len < PAGE_SIZE - 2) + len += snprintf(buf + len, PAGE_SIZE - len, "\n"); return min_t(int, len, PAGE_SIZE); } @@ -1641,6 +1696,23 @@ static int input_add_uevent_bm_var(struct kobj_uevent_env *env, return 0; } +/* + * This is a pretty gross hack. When building uevent data the driver core + * may try adding more environment variables to kobj_uevent_env without + * telling us, so we have no idea how much of the buffer we can use to + * avoid overflows/-ENOMEM elsewhere. To work around this let's artificially + * reduce amount of memory we will use for the modalias environment variable. + * + * The potential additions are: + * + * SEQNUM=18446744073709551615 - (%llu - 28 bytes) + * HOME=/ (6 bytes) + * PATH=/sbin:/bin:/usr/sbin:/usr/bin (34 bytes) + * + * 68 bytes total. Allow extra buffer - 96 bytes + */ +#define UEVENT_ENV_EXTRA_LEN 96 + static int input_add_uevent_modalias_var(struct kobj_uevent_env *env, const struct input_dev *dev) { @@ -1650,9 +1722,11 @@ static int input_add_uevent_modalias_var(struct kobj_uevent_env *env, return -ENOMEM; len = input_print_modalias(&env->buf[env->buflen - 1], - sizeof(env->buf) - env->buflen, - dev, 0); - if (len >= (sizeof(env->buf) - env->buflen)) + (int)sizeof(env->buf) - env->buflen - + UEVENT_ENV_EXTRA_LEN, + dev); + if (len >= ((int)sizeof(env->buf) - env->buflen - + UEVENT_ENV_EXTRA_LEN)) return -ENOMEM; env->buflen += len;

7 months, 2 weeks

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FAILED: patch "[PATCH] Input: try trimming too long modalias strings" failed to apply to 5.15-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.15-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y git checkout FETCH_HEAD git cherry-pick -x 0774d19038c496f0c3602fb505c43e1b2d8eed85 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024052509-curvature-profane-0ac3@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 0774d19038c496f0c3602fb505c43e1b2d8eed85 Mon Sep 17 00:00:00 2001 From: Dmitry Torokhov <dmitry.torokhov(a)gmail.com> Date: Mon, 29 Apr 2024 14:50:41 -0700 Subject: [PATCH] Input: try trimming too long modalias strings If an input device declares too many capability bits then modalias string for such device may become too long and not fit into uevent buffer, resulting in failure of sending said uevent. This, in turn, may prevent userspace from recognizing existence of such devices. This is typically not a concern for real hardware devices as they have limited number of keys, but happen with synthetic devices such as ones created by xen-kbdfront driver, which creates devices as being capable of delivering all possible keys, since it doesn't know what keys the backend may produce. To deal with such devices input core will attempt to trim key data, in the hope that the rest of modalias string will fit in the given buffer. When trimming key data it will indicate that it is not complete by placing "+," sign, resulting in conversions like this: old: k71,72,73,74,78,7A,7B,7C,7D,8E,9E,A4,AD,E0,E1,E4,F8,174, new: k71,72,73,74,78,7A,7B,7C,+, This should allow existing udev rules continue to work with existing devices, and will also allow writing more complex rules that would recognize trimmed modalias and check input device characteristics by other means (for example by parsing KEY= data in uevent or parsing input device sysfs attributes). Note that the driver core may try adding more uevent environment variables once input core is done adding its own, so when forming modalias we can not use the entire available buffer, so we reduce it by somewhat an arbitrary amount (96 bytes). Reported-by: Jason Andryuk <jandryuk(a)gmail.com> Reviewed-by: Peter Hutterer <peter.hutterer(a)who-t.net> Tested-by: Jason Andryuk <jandryuk(a)gmail.com> Link: https://lore.kernel.org/r/ZjAWMQCJdrxZkvkB@google.com Cc: stable(a)vger.kernel.org Signed-off-by: Dmitry Torokhov <dmitry.torokhov(a)gmail.com> diff --git a/drivers/input/input.c b/drivers/input/input.c index 711485437567..fd4997ba263c 100644 --- a/drivers/input/input.c +++ b/drivers/input/input.c @@ -1378,19 +1378,19 @@ static int input_print_modalias_bits(char *buf, int size, char name, const unsigned long *bm, unsigned int min_bit, unsigned int max_bit) { - int len = 0, i; + int bit = min_bit; + int len = 0; len += snprintf(buf, max(size, 0), "%c", name); - for (i = min_bit; i < max_bit; i++) - if (bm[BIT_WORD(i)] & BIT_MASK(i)) - len += snprintf(buf + len, max(size - len, 0), "%X,", i); + for_each_set_bit_from(bit, bm, max_bit) + len += snprintf(buf + len, max(size - len, 0), "%X,", bit); return len; } -static int input_print_modalias(char *buf, int size, const struct input_dev *id, - int add_cr) +static int input_print_modalias_parts(char *buf, int size, int full_len, + const struct input_dev *id) { - int len; + int len, klen, remainder, space; len = snprintf(buf, max(size, 0), "input:b%04Xv%04Xp%04Xe%04X-", @@ -1399,8 +1399,48 @@ static int input_print_modalias(char *buf, int size, const struct input_dev *id, len += input_print_modalias_bits(buf + len, size - len, 'e', id->evbit, 0, EV_MAX); - len += input_print_modalias_bits(buf + len, size - len, + + /* + * Calculate the remaining space in the buffer making sure we + * have place for the terminating 0. + */ + space = max(size - (len + 1), 0); + + klen = input_print_modalias_bits(buf + len, size - len, 'k', id->keybit, KEY_MIN_INTERESTING, KEY_MAX); + len += klen; + + /* + * If we have more data than we can fit in the buffer, check + * if we can trim key data to fit in the rest. We will indicate + * that key data is incomplete by adding "+" sign at the end, like + * this: * "k1,2,3,45,+,". + * + * Note that we shortest key info (if present) is "k+," so we + * can only try to trim if key data is longer than that. + */ + if (full_len && size < full_len + 1 && klen > 3) { + remainder = full_len - len; + /* + * We can only trim if we have space for the remainder + * and also for at least "k+," which is 3 more characters. + */ + if (remainder <= space - 3) { + /* + * We are guaranteed to have 'k' in the buffer, so + * we need at least 3 additional bytes for storing + * "+," in addition to the remainder. + */ + for (int i = size - 1 - remainder - 3; i >= 0; i--) { + if (buf[i] == 'k' || buf[i] == ',') { + strcpy(buf + i + 1, "+,"); + len = i + 3; /* Not counting '\0' */ + break; + } + } + } + } + len += input_print_modalias_bits(buf + len, size - len, 'r', id->relbit, 0, REL_MAX); len += input_print_modalias_bits(buf + len, size - len, @@ -1416,12 +1456,25 @@ static int input_print_modalias(char *buf, int size, const struct input_dev *id, len += input_print_modalias_bits(buf + len, size - len, 'w', id->swbit, 0, SW_MAX); - if (add_cr) - len += snprintf(buf + len, max(size - len, 0), "\n"); - return len; } +static int input_print_modalias(char *buf, int size, const struct input_dev *id) +{ + int full_len; + + /* + * Printing is done in 2 passes: first one figures out total length + * needed for the modalias string, second one will try to trim key + * data in case when buffer is too small for the entire modalias. + * If the buffer is too small regardless, it will fill as much as it + * can (without trimming key data) into the buffer and leave it to + * the caller to figure out what to do with the result. + */ + full_len = input_print_modalias_parts(NULL, 0, 0, id); + return input_print_modalias_parts(buf, size, full_len, id); +} + static ssize_t input_dev_show_modalias(struct device *dev, struct device_attribute *attr, char *buf) @@ -1429,7 +1482,9 @@ static ssize_t input_dev_show_modalias(struct device *dev, struct input_dev *id = to_input_dev(dev); ssize_t len; - len = input_print_modalias(buf, PAGE_SIZE, id, 1); + len = input_print_modalias(buf, PAGE_SIZE, id); + if (len < PAGE_SIZE - 2) + len += snprintf(buf + len, PAGE_SIZE - len, "\n"); return min_t(int, len, PAGE_SIZE); } @@ -1641,6 +1696,23 @@ static int input_add_uevent_bm_var(struct kobj_uevent_env *env, return 0; } +/* + * This is a pretty gross hack. When building uevent data the driver core + * may try adding more environment variables to kobj_uevent_env without + * telling us, so we have no idea how much of the buffer we can use to + * avoid overflows/-ENOMEM elsewhere. To work around this let's artificially + * reduce amount of memory we will use for the modalias environment variable. + * + * The potential additions are: + * + * SEQNUM=18446744073709551615 - (%llu - 28 bytes) + * HOME=/ (6 bytes) + * PATH=/sbin:/bin:/usr/sbin:/usr/bin (34 bytes) + * + * 68 bytes total. Allow extra buffer - 96 bytes + */ +#define UEVENT_ENV_EXTRA_LEN 96 + static int input_add_uevent_modalias_var(struct kobj_uevent_env *env, const struct input_dev *dev) { @@ -1650,9 +1722,11 @@ static int input_add_uevent_modalias_var(struct kobj_uevent_env *env, return -ENOMEM; len = input_print_modalias(&env->buf[env->buflen - 1], - sizeof(env->buf) - env->buflen, - dev, 0); - if (len >= (sizeof(env->buf) - env->buflen)) + (int)sizeof(env->buf) - env->buflen - + UEVENT_ENV_EXTRA_LEN, + dev); + if (len >= ((int)sizeof(env->buf) - env->buflen - + UEVENT_ENV_EXTRA_LEN)) return -ENOMEM; env->buflen += len;

7 months, 2 weeks

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0 0

FAILED: patch "[PATCH] Input: try trimming too long modalias strings" failed to apply to 6.1-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 6.1-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.1.y git checkout FETCH_HEAD git cherry-pick -x 0774d19038c496f0c3602fb505c43e1b2d8eed85 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024052508-stoke-gibberish-c092@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 0774d19038c496f0c3602fb505c43e1b2d8eed85 Mon Sep 17 00:00:00 2001 From: Dmitry Torokhov <dmitry.torokhov(a)gmail.com> Date: Mon, 29 Apr 2024 14:50:41 -0700 Subject: [PATCH] Input: try trimming too long modalias strings If an input device declares too many capability bits then modalias string for such device may become too long and not fit into uevent buffer, resulting in failure of sending said uevent. This, in turn, may prevent userspace from recognizing existence of such devices. This is typically not a concern for real hardware devices as they have limited number of keys, but happen with synthetic devices such as ones created by xen-kbdfront driver, which creates devices as being capable of delivering all possible keys, since it doesn't know what keys the backend may produce. To deal with such devices input core will attempt to trim key data, in the hope that the rest of modalias string will fit in the given buffer. When trimming key data it will indicate that it is not complete by placing "+," sign, resulting in conversions like this: old: k71,72,73,74,78,7A,7B,7C,7D,8E,9E,A4,AD,E0,E1,E4,F8,174, new: k71,72,73,74,78,7A,7B,7C,+, This should allow existing udev rules continue to work with existing devices, and will also allow writing more complex rules that would recognize trimmed modalias and check input device characteristics by other means (for example by parsing KEY= data in uevent or parsing input device sysfs attributes). Note that the driver core may try adding more uevent environment variables once input core is done adding its own, so when forming modalias we can not use the entire available buffer, so we reduce it by somewhat an arbitrary amount (96 bytes). Reported-by: Jason Andryuk <jandryuk(a)gmail.com> Reviewed-by: Peter Hutterer <peter.hutterer(a)who-t.net> Tested-by: Jason Andryuk <jandryuk(a)gmail.com> Link: https://lore.kernel.org/r/ZjAWMQCJdrxZkvkB@google.com Cc: stable(a)vger.kernel.org Signed-off-by: Dmitry Torokhov <dmitry.torokhov(a)gmail.com> diff --git a/drivers/input/input.c b/drivers/input/input.c index 711485437567..fd4997ba263c 100644 --- a/drivers/input/input.c +++ b/drivers/input/input.c @@ -1378,19 +1378,19 @@ static int input_print_modalias_bits(char *buf, int size, char name, const unsigned long *bm, unsigned int min_bit, unsigned int max_bit) { - int len = 0, i; + int bit = min_bit; + int len = 0; len += snprintf(buf, max(size, 0), "%c", name); - for (i = min_bit; i < max_bit; i++) - if (bm[BIT_WORD(i)] & BIT_MASK(i)) - len += snprintf(buf + len, max(size - len, 0), "%X,", i); + for_each_set_bit_from(bit, bm, max_bit) + len += snprintf(buf + len, max(size - len, 0), "%X,", bit); return len; } -static int input_print_modalias(char *buf, int size, const struct input_dev *id, - int add_cr) +static int input_print_modalias_parts(char *buf, int size, int full_len, + const struct input_dev *id) { - int len; + int len, klen, remainder, space; len = snprintf(buf, max(size, 0), "input:b%04Xv%04Xp%04Xe%04X-", @@ -1399,8 +1399,48 @@ static int input_print_modalias(char *buf, int size, const struct input_dev *id, len += input_print_modalias_bits(buf + len, size - len, 'e', id->evbit, 0, EV_MAX); - len += input_print_modalias_bits(buf + len, size - len, + + /* + * Calculate the remaining space in the buffer making sure we + * have place for the terminating 0. + */ + space = max(size - (len + 1), 0); + + klen = input_print_modalias_bits(buf + len, size - len, 'k', id->keybit, KEY_MIN_INTERESTING, KEY_MAX); + len += klen; + + /* + * If we have more data than we can fit in the buffer, check + * if we can trim key data to fit in the rest. We will indicate + * that key data is incomplete by adding "+" sign at the end, like + * this: * "k1,2,3,45,+,". + * + * Note that we shortest key info (if present) is "k+," so we + * can only try to trim if key data is longer than that. + */ + if (full_len && size < full_len + 1 && klen > 3) { + remainder = full_len - len; + /* + * We can only trim if we have space for the remainder + * and also for at least "k+," which is 3 more characters. + */ + if (remainder <= space - 3) { + /* + * We are guaranteed to have 'k' in the buffer, so + * we need at least 3 additional bytes for storing + * "+," in addition to the remainder. + */ + for (int i = size - 1 - remainder - 3; i >= 0; i--) { + if (buf[i] == 'k' || buf[i] == ',') { + strcpy(buf + i + 1, "+,"); + len = i + 3; /* Not counting '\0' */ + break; + } + } + } + } + len += input_print_modalias_bits(buf + len, size - len, 'r', id->relbit, 0, REL_MAX); len += input_print_modalias_bits(buf + len, size - len, @@ -1416,12 +1456,25 @@ static int input_print_modalias(char *buf, int size, const struct input_dev *id, len += input_print_modalias_bits(buf + len, size - len, 'w', id->swbit, 0, SW_MAX); - if (add_cr) - len += snprintf(buf + len, max(size - len, 0), "\n"); - return len; } +static int input_print_modalias(char *buf, int size, const struct input_dev *id) +{ + int full_len; + + /* + * Printing is done in 2 passes: first one figures out total length + * needed for the modalias string, second one will try to trim key + * data in case when buffer is too small for the entire modalias. + * If the buffer is too small regardless, it will fill as much as it + * can (without trimming key data) into the buffer and leave it to + * the caller to figure out what to do with the result. + */ + full_len = input_print_modalias_parts(NULL, 0, 0, id); + return input_print_modalias_parts(buf, size, full_len, id); +} + static ssize_t input_dev_show_modalias(struct device *dev, struct device_attribute *attr, char *buf) @@ -1429,7 +1482,9 @@ static ssize_t input_dev_show_modalias(struct device *dev, struct input_dev *id = to_input_dev(dev); ssize_t len; - len = input_print_modalias(buf, PAGE_SIZE, id, 1); + len = input_print_modalias(buf, PAGE_SIZE, id); + if (len < PAGE_SIZE - 2) + len += snprintf(buf + len, PAGE_SIZE - len, "\n"); return min_t(int, len, PAGE_SIZE); } @@ -1641,6 +1696,23 @@ static int input_add_uevent_bm_var(struct kobj_uevent_env *env, return 0; } +/* + * This is a pretty gross hack. When building uevent data the driver core + * may try adding more environment variables to kobj_uevent_env without + * telling us, so we have no idea how much of the buffer we can use to + * avoid overflows/-ENOMEM elsewhere. To work around this let's artificially + * reduce amount of memory we will use for the modalias environment variable. + * + * The potential additions are: + * + * SEQNUM=18446744073709551615 - (%llu - 28 bytes) + * HOME=/ (6 bytes) + * PATH=/sbin:/bin:/usr/sbin:/usr/bin (34 bytes) + * + * 68 bytes total. Allow extra buffer - 96 bytes + */ +#define UEVENT_ENV_EXTRA_LEN 96 + static int input_add_uevent_modalias_var(struct kobj_uevent_env *env, const struct input_dev *dev) { @@ -1650,9 +1722,11 @@ static int input_add_uevent_modalias_var(struct kobj_uevent_env *env, return -ENOMEM; len = input_print_modalias(&env->buf[env->buflen - 1], - sizeof(env->buf) - env->buflen, - dev, 0); - if (len >= (sizeof(env->buf) - env->buflen)) + (int)sizeof(env->buf) - env->buflen - + UEVENT_ENV_EXTRA_LEN, + dev); + if (len >= ((int)sizeof(env->buf) - env->buflen - + UEVENT_ENV_EXTRA_LEN)) return -ENOMEM; env->buflen += len;

7 months, 2 weeks

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FAILED: patch "[PATCH] serial: sc16is7xx: fix bug in sc16is7xx_set_baud() when using" failed to apply to 4.19-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 4.19-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-4.19.y git checkout FETCH_HEAD git cherry-pick -x 8492bd91aa055907c67ef04f2b56f6dadd1f44bf # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024052509-agreement-quilt-f251@gregkh' --subject-prefix 'PATCH 4.19.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 8492bd91aa055907c67ef04f2b56f6dadd1f44bf Mon Sep 17 00:00:00 2001 From: Hugo Villeneuve <hvilleneuve(a)dimonoff.com> Date: Tue, 30 Apr 2024 16:04:30 -0400 Subject: [PATCH] serial: sc16is7xx: fix bug in sc16is7xx_set_baud() when using prescaler When using a high speed clock with a low baud rate, the 4x prescaler is automatically selected if required. In that case, sc16is7xx_set_baud() properly configures the chip registers, but returns an incorrect baud rate by not taking into account the prescaler value. This incorrect baud rate is then fed to uart_update_timeout(). For example, with an input clock of 80MHz, and a selected baud rate of 50, sc16is7xx_set_baud() will return 200 instead of 50. Fix this by first changing the prescaler variable to hold the selected prescaler value instead of the MCR bitfield. Then properly take into account the selected prescaler value in the return value computation. Also add better documentation about the divisor value computation. Fixes: dfeae619d781 ("serial: sc16is7xx") Cc: stable(a)vger.kernel.org Signed-off-by: Hugo Villeneuve <hvilleneuve(a)dimonoff.com> Reviewed-by: Jiri Slaby <jirislaby(a)kernel.org> Link: https://lore.kernel.org/r/20240430200431.4102923-1-hugo@hugovil.com Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> diff --git a/drivers/tty/serial/sc16is7xx.c b/drivers/tty/serial/sc16is7xx.c index 929206a9a6e1..12915fffac27 100644 --- a/drivers/tty/serial/sc16is7xx.c +++ b/drivers/tty/serial/sc16is7xx.c @@ -554,16 +554,28 @@ static bool sc16is7xx_regmap_noinc(struct device *dev, unsigned int reg) return reg == SC16IS7XX_RHR_REG; } +/* + * Configure programmable baud rate generator (divisor) according to the + * desired baud rate. + * + * From the datasheet, the divisor is computed according to: + * + * XTAL1 input frequency + * ----------------------- + * prescaler + * divisor = --------------------------- + * baud-rate x sampling-rate + */ static int sc16is7xx_set_baud(struct uart_port *port, int baud) { struct sc16is7xx_one *one = to_sc16is7xx_one(port, port); u8 lcr; - u8 prescaler = 0; + unsigned int prescaler = 1; unsigned long clk = port->uartclk, div = clk / 16 / baud; if (div >= BIT(16)) { - prescaler = SC16IS7XX_MCR_CLKSEL_BIT; - div /= 4; + prescaler = 4; + div /= prescaler; } /* Enable enhanced features */ @@ -573,9 +585,10 @@ static int sc16is7xx_set_baud(struct uart_port *port, int baud) SC16IS7XX_EFR_ENABLE_BIT); sc16is7xx_efr_unlock(port); + /* If bit MCR_CLKSEL is set, the divide by 4 prescaler is activated. */ sc16is7xx_port_update(port, SC16IS7XX_MCR_REG, SC16IS7XX_MCR_CLKSEL_BIT, - prescaler); + prescaler == 1 ? 0 : SC16IS7XX_MCR_CLKSEL_BIT); /* Backup LCR and access special register set (DLL/DLH) */ lcr = sc16is7xx_port_read(port, SC16IS7XX_LCR_REG); @@ -591,7 +604,7 @@ static int sc16is7xx_set_baud(struct uart_port *port, int baud) /* Restore LCR and access to general register set */ sc16is7xx_port_write(port, SC16IS7XX_LCR_REG, lcr); - return DIV_ROUND_CLOSEST(clk / 16, div); + return DIV_ROUND_CLOSEST((clk / prescaler) / 16, div); } static void sc16is7xx_handle_rx(struct uart_port *port, unsigned int rxlen,

7 months, 2 weeks

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FAILED: patch "[PATCH] serial: sc16is7xx: fix bug in sc16is7xx_set_baud() when using" failed to apply to 5.4-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.4.y git checkout FETCH_HEAD git cherry-pick -x 8492bd91aa055907c67ef04f2b56f6dadd1f44bf # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024052508-corporate-mayday-15b7@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 8492bd91aa055907c67ef04f2b56f6dadd1f44bf Mon Sep 17 00:00:00 2001 From: Hugo Villeneuve <hvilleneuve(a)dimonoff.com> Date: Tue, 30 Apr 2024 16:04:30 -0400 Subject: [PATCH] serial: sc16is7xx: fix bug in sc16is7xx_set_baud() when using prescaler When using a high speed clock with a low baud rate, the 4x prescaler is automatically selected if required. In that case, sc16is7xx_set_baud() properly configures the chip registers, but returns an incorrect baud rate by not taking into account the prescaler value. This incorrect baud rate is then fed to uart_update_timeout(). For example, with an input clock of 80MHz, and a selected baud rate of 50, sc16is7xx_set_baud() will return 200 instead of 50. Fix this by first changing the prescaler variable to hold the selected prescaler value instead of the MCR bitfield. Then properly take into account the selected prescaler value in the return value computation. Also add better documentation about the divisor value computation. Fixes: dfeae619d781 ("serial: sc16is7xx") Cc: stable(a)vger.kernel.org Signed-off-by: Hugo Villeneuve <hvilleneuve(a)dimonoff.com> Reviewed-by: Jiri Slaby <jirislaby(a)kernel.org> Link: https://lore.kernel.org/r/20240430200431.4102923-1-hugo@hugovil.com Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> diff --git a/drivers/tty/serial/sc16is7xx.c b/drivers/tty/serial/sc16is7xx.c index 929206a9a6e1..12915fffac27 100644 --- a/drivers/tty/serial/sc16is7xx.c +++ b/drivers/tty/serial/sc16is7xx.c @@ -554,16 +554,28 @@ static bool sc16is7xx_regmap_noinc(struct device *dev, unsigned int reg) return reg == SC16IS7XX_RHR_REG; } +/* + * Configure programmable baud rate generator (divisor) according to the + * desired baud rate. + * + * From the datasheet, the divisor is computed according to: + * + * XTAL1 input frequency + * ----------------------- + * prescaler + * divisor = --------------------------- + * baud-rate x sampling-rate + */ static int sc16is7xx_set_baud(struct uart_port *port, int baud) { struct sc16is7xx_one *one = to_sc16is7xx_one(port, port); u8 lcr; - u8 prescaler = 0; + unsigned int prescaler = 1; unsigned long clk = port->uartclk, div = clk / 16 / baud; if (div >= BIT(16)) { - prescaler = SC16IS7XX_MCR_CLKSEL_BIT; - div /= 4; + prescaler = 4; + div /= prescaler; } /* Enable enhanced features */ @@ -573,9 +585,10 @@ static int sc16is7xx_set_baud(struct uart_port *port, int baud) SC16IS7XX_EFR_ENABLE_BIT); sc16is7xx_efr_unlock(port); + /* If bit MCR_CLKSEL is set, the divide by 4 prescaler is activated. */ sc16is7xx_port_update(port, SC16IS7XX_MCR_REG, SC16IS7XX_MCR_CLKSEL_BIT, - prescaler); + prescaler == 1 ? 0 : SC16IS7XX_MCR_CLKSEL_BIT); /* Backup LCR and access special register set (DLL/DLH) */ lcr = sc16is7xx_port_read(port, SC16IS7XX_LCR_REG); @@ -591,7 +604,7 @@ static int sc16is7xx_set_baud(struct uart_port *port, int baud) /* Restore LCR and access to general register set */ sc16is7xx_port_write(port, SC16IS7XX_LCR_REG, lcr); - return DIV_ROUND_CLOSEST(clk / 16, div); + return DIV_ROUND_CLOSEST((clk / prescaler) / 16, div); } static void sc16is7xx_handle_rx(struct uart_port *port, unsigned int rxlen,

7 months, 2 weeks

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FAILED: patch "[PATCH] serial: sc16is7xx: fix bug in sc16is7xx_set_baud() when using" failed to apply to 5.10-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.10-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.10.y git checkout FETCH_HEAD git cherry-pick -x 8492bd91aa055907c67ef04f2b56f6dadd1f44bf # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024052507-catty-penniless-a423@gregkh' --subject-prefix 'PATCH 5.10.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 8492bd91aa055907c67ef04f2b56f6dadd1f44bf Mon Sep 17 00:00:00 2001 From: Hugo Villeneuve <hvilleneuve(a)dimonoff.com> Date: Tue, 30 Apr 2024 16:04:30 -0400 Subject: [PATCH] serial: sc16is7xx: fix bug in sc16is7xx_set_baud() when using prescaler When using a high speed clock with a low baud rate, the 4x prescaler is automatically selected if required. In that case, sc16is7xx_set_baud() properly configures the chip registers, but returns an incorrect baud rate by not taking into account the prescaler value. This incorrect baud rate is then fed to uart_update_timeout(). For example, with an input clock of 80MHz, and a selected baud rate of 50, sc16is7xx_set_baud() will return 200 instead of 50. Fix this by first changing the prescaler variable to hold the selected prescaler value instead of the MCR bitfield. Then properly take into account the selected prescaler value in the return value computation. Also add better documentation about the divisor value computation. Fixes: dfeae619d781 ("serial: sc16is7xx") Cc: stable(a)vger.kernel.org Signed-off-by: Hugo Villeneuve <hvilleneuve(a)dimonoff.com> Reviewed-by: Jiri Slaby <jirislaby(a)kernel.org> Link: https://lore.kernel.org/r/20240430200431.4102923-1-hugo@hugovil.com Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> diff --git a/drivers/tty/serial/sc16is7xx.c b/drivers/tty/serial/sc16is7xx.c index 929206a9a6e1..12915fffac27 100644 --- a/drivers/tty/serial/sc16is7xx.c +++ b/drivers/tty/serial/sc16is7xx.c @@ -554,16 +554,28 @@ static bool sc16is7xx_regmap_noinc(struct device *dev, unsigned int reg) return reg == SC16IS7XX_RHR_REG; } +/* + * Configure programmable baud rate generator (divisor) according to the + * desired baud rate. + * + * From the datasheet, the divisor is computed according to: + * + * XTAL1 input frequency + * ----------------------- + * prescaler + * divisor = --------------------------- + * baud-rate x sampling-rate + */ static int sc16is7xx_set_baud(struct uart_port *port, int baud) { struct sc16is7xx_one *one = to_sc16is7xx_one(port, port); u8 lcr; - u8 prescaler = 0; + unsigned int prescaler = 1; unsigned long clk = port->uartclk, div = clk / 16 / baud; if (div >= BIT(16)) { - prescaler = SC16IS7XX_MCR_CLKSEL_BIT; - div /= 4; + prescaler = 4; + div /= prescaler; } /* Enable enhanced features */ @@ -573,9 +585,10 @@ static int sc16is7xx_set_baud(struct uart_port *port, int baud) SC16IS7XX_EFR_ENABLE_BIT); sc16is7xx_efr_unlock(port); + /* If bit MCR_CLKSEL is set, the divide by 4 prescaler is activated. */ sc16is7xx_port_update(port, SC16IS7XX_MCR_REG, SC16IS7XX_MCR_CLKSEL_BIT, - prescaler); + prescaler == 1 ? 0 : SC16IS7XX_MCR_CLKSEL_BIT); /* Backup LCR and access special register set (DLL/DLH) */ lcr = sc16is7xx_port_read(port, SC16IS7XX_LCR_REG); @@ -591,7 +604,7 @@ static int sc16is7xx_set_baud(struct uart_port *port, int baud) /* Restore LCR and access to general register set */ sc16is7xx_port_write(port, SC16IS7XX_LCR_REG, lcr); - return DIV_ROUND_CLOSEST(clk / 16, div); + return DIV_ROUND_CLOSEST((clk / prescaler) / 16, div); } static void sc16is7xx_handle_rx(struct uart_port *port, unsigned int rxlen,

7 months, 2 weeks

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FAILED: patch "[PATCH] serial: sc16is7xx: fix bug in sc16is7xx_set_baud() when using" failed to apply to 5.15-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.15-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y git checkout FETCH_HEAD git cherry-pick -x 8492bd91aa055907c67ef04f2b56f6dadd1f44bf # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024052506-afternoon-exponent-b101@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 8492bd91aa055907c67ef04f2b56f6dadd1f44bf Mon Sep 17 00:00:00 2001 From: Hugo Villeneuve <hvilleneuve(a)dimonoff.com> Date: Tue, 30 Apr 2024 16:04:30 -0400 Subject: [PATCH] serial: sc16is7xx: fix bug in sc16is7xx_set_baud() when using prescaler When using a high speed clock with a low baud rate, the 4x prescaler is automatically selected if required. In that case, sc16is7xx_set_baud() properly configures the chip registers, but returns an incorrect baud rate by not taking into account the prescaler value. This incorrect baud rate is then fed to uart_update_timeout(). For example, with an input clock of 80MHz, and a selected baud rate of 50, sc16is7xx_set_baud() will return 200 instead of 50. Fix this by first changing the prescaler variable to hold the selected prescaler value instead of the MCR bitfield. Then properly take into account the selected prescaler value in the return value computation. Also add better documentation about the divisor value computation. Fixes: dfeae619d781 ("serial: sc16is7xx") Cc: stable(a)vger.kernel.org Signed-off-by: Hugo Villeneuve <hvilleneuve(a)dimonoff.com> Reviewed-by: Jiri Slaby <jirislaby(a)kernel.org> Link: https://lore.kernel.org/r/20240430200431.4102923-1-hugo@hugovil.com Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> diff --git a/drivers/tty/serial/sc16is7xx.c b/drivers/tty/serial/sc16is7xx.c index 929206a9a6e1..12915fffac27 100644 --- a/drivers/tty/serial/sc16is7xx.c +++ b/drivers/tty/serial/sc16is7xx.c @@ -554,16 +554,28 @@ static bool sc16is7xx_regmap_noinc(struct device *dev, unsigned int reg) return reg == SC16IS7XX_RHR_REG; } +/* + * Configure programmable baud rate generator (divisor) according to the + * desired baud rate. + * + * From the datasheet, the divisor is computed according to: + * + * XTAL1 input frequency + * ----------------------- + * prescaler + * divisor = --------------------------- + * baud-rate x sampling-rate + */ static int sc16is7xx_set_baud(struct uart_port *port, int baud) { struct sc16is7xx_one *one = to_sc16is7xx_one(port, port); u8 lcr; - u8 prescaler = 0; + unsigned int prescaler = 1; unsigned long clk = port->uartclk, div = clk / 16 / baud; if (div >= BIT(16)) { - prescaler = SC16IS7XX_MCR_CLKSEL_BIT; - div /= 4; + prescaler = 4; + div /= prescaler; } /* Enable enhanced features */ @@ -573,9 +585,10 @@ static int sc16is7xx_set_baud(struct uart_port *port, int baud) SC16IS7XX_EFR_ENABLE_BIT); sc16is7xx_efr_unlock(port); + /* If bit MCR_CLKSEL is set, the divide by 4 prescaler is activated. */ sc16is7xx_port_update(port, SC16IS7XX_MCR_REG, SC16IS7XX_MCR_CLKSEL_BIT, - prescaler); + prescaler == 1 ? 0 : SC16IS7XX_MCR_CLKSEL_BIT); /* Backup LCR and access special register set (DLL/DLH) */ lcr = sc16is7xx_port_read(port, SC16IS7XX_LCR_REG); @@ -591,7 +604,7 @@ static int sc16is7xx_set_baud(struct uart_port *port, int baud) /* Restore LCR and access to general register set */ sc16is7xx_port_write(port, SC16IS7XX_LCR_REG, lcr); - return DIV_ROUND_CLOSEST(clk / 16, div); + return DIV_ROUND_CLOSEST((clk / prescaler) / 16, div); } static void sc16is7xx_handle_rx(struct uart_port *port, unsigned int rxlen,

7 months, 2 weeks

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FAILED: patch "[PATCH] serial: sc16is7xx: fix bug in sc16is7xx_set_baud() when using" failed to apply to 6.1-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 6.1-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.1.y git checkout FETCH_HEAD git cherry-pick -x 8492bd91aa055907c67ef04f2b56f6dadd1f44bf # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024052505-conceded-backstage-2637@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 8492bd91aa055907c67ef04f2b56f6dadd1f44bf Mon Sep 17 00:00:00 2001 From: Hugo Villeneuve <hvilleneuve(a)dimonoff.com> Date: Tue, 30 Apr 2024 16:04:30 -0400 Subject: [PATCH] serial: sc16is7xx: fix bug in sc16is7xx_set_baud() when using prescaler When using a high speed clock with a low baud rate, the 4x prescaler is automatically selected if required. In that case, sc16is7xx_set_baud() properly configures the chip registers, but returns an incorrect baud rate by not taking into account the prescaler value. This incorrect baud rate is then fed to uart_update_timeout(). For example, with an input clock of 80MHz, and a selected baud rate of 50, sc16is7xx_set_baud() will return 200 instead of 50. Fix this by first changing the prescaler variable to hold the selected prescaler value instead of the MCR bitfield. Then properly take into account the selected prescaler value in the return value computation. Also add better documentation about the divisor value computation. Fixes: dfeae619d781 ("serial: sc16is7xx") Cc: stable(a)vger.kernel.org Signed-off-by: Hugo Villeneuve <hvilleneuve(a)dimonoff.com> Reviewed-by: Jiri Slaby <jirislaby(a)kernel.org> Link: https://lore.kernel.org/r/20240430200431.4102923-1-hugo@hugovil.com Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> diff --git a/drivers/tty/serial/sc16is7xx.c b/drivers/tty/serial/sc16is7xx.c index 929206a9a6e1..12915fffac27 100644 --- a/drivers/tty/serial/sc16is7xx.c +++ b/drivers/tty/serial/sc16is7xx.c @@ -554,16 +554,28 @@ static bool sc16is7xx_regmap_noinc(struct device *dev, unsigned int reg) return reg == SC16IS7XX_RHR_REG; } +/* + * Configure programmable baud rate generator (divisor) according to the + * desired baud rate. + * + * From the datasheet, the divisor is computed according to: + * + * XTAL1 input frequency + * ----------------------- + * prescaler + * divisor = --------------------------- + * baud-rate x sampling-rate + */ static int sc16is7xx_set_baud(struct uart_port *port, int baud) { struct sc16is7xx_one *one = to_sc16is7xx_one(port, port); u8 lcr; - u8 prescaler = 0; + unsigned int prescaler = 1; unsigned long clk = port->uartclk, div = clk / 16 / baud; if (div >= BIT(16)) { - prescaler = SC16IS7XX_MCR_CLKSEL_BIT; - div /= 4; + prescaler = 4; + div /= prescaler; } /* Enable enhanced features */ @@ -573,9 +585,10 @@ static int sc16is7xx_set_baud(struct uart_port *port, int baud) SC16IS7XX_EFR_ENABLE_BIT); sc16is7xx_efr_unlock(port); + /* If bit MCR_CLKSEL is set, the divide by 4 prescaler is activated. */ sc16is7xx_port_update(port, SC16IS7XX_MCR_REG, SC16IS7XX_MCR_CLKSEL_BIT, - prescaler); + prescaler == 1 ? 0 : SC16IS7XX_MCR_CLKSEL_BIT); /* Backup LCR and access special register set (DLL/DLH) */ lcr = sc16is7xx_port_read(port, SC16IS7XX_LCR_REG); @@ -591,7 +604,7 @@ static int sc16is7xx_set_baud(struct uart_port *port, int baud) /* Restore LCR and access to general register set */ sc16is7xx_port_write(port, SC16IS7XX_LCR_REG, lcr); - return DIV_ROUND_CLOSEST(clk / 16, div); + return DIV_ROUND_CLOSEST((clk / prescaler) / 16, div); } static void sc16is7xx_handle_rx(struct uart_port *port, unsigned int rxlen,

7 months, 2 weeks

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FAILED: patch "[PATCH] serial: sc16is7xx: fix bug in sc16is7xx_set_baud() when using" failed to apply to 6.6-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 6.6-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y git checkout FETCH_HEAD git cherry-pick -x 8492bd91aa055907c67ef04f2b56f6dadd1f44bf # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024052504-hungrily-verdict-1471@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 8492bd91aa055907c67ef04f2b56f6dadd1f44bf Mon Sep 17 00:00:00 2001 From: Hugo Villeneuve <hvilleneuve(a)dimonoff.com> Date: Tue, 30 Apr 2024 16:04:30 -0400 Subject: [PATCH] serial: sc16is7xx: fix bug in sc16is7xx_set_baud() when using prescaler When using a high speed clock with a low baud rate, the 4x prescaler is automatically selected if required. In that case, sc16is7xx_set_baud() properly configures the chip registers, but returns an incorrect baud rate by not taking into account the prescaler value. This incorrect baud rate is then fed to uart_update_timeout(). For example, with an input clock of 80MHz, and a selected baud rate of 50, sc16is7xx_set_baud() will return 200 instead of 50. Fix this by first changing the prescaler variable to hold the selected prescaler value instead of the MCR bitfield. Then properly take into account the selected prescaler value in the return value computation. Also add better documentation about the divisor value computation. Fixes: dfeae619d781 ("serial: sc16is7xx") Cc: stable(a)vger.kernel.org Signed-off-by: Hugo Villeneuve <hvilleneuve(a)dimonoff.com> Reviewed-by: Jiri Slaby <jirislaby(a)kernel.org> Link: https://lore.kernel.org/r/20240430200431.4102923-1-hugo@hugovil.com Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> diff --git a/drivers/tty/serial/sc16is7xx.c b/drivers/tty/serial/sc16is7xx.c index 929206a9a6e1..12915fffac27 100644 --- a/drivers/tty/serial/sc16is7xx.c +++ b/drivers/tty/serial/sc16is7xx.c @@ -554,16 +554,28 @@ static bool sc16is7xx_regmap_noinc(struct device *dev, unsigned int reg) return reg == SC16IS7XX_RHR_REG; } +/* + * Configure programmable baud rate generator (divisor) according to the + * desired baud rate. + * + * From the datasheet, the divisor is computed according to: + * + * XTAL1 input frequency + * ----------------------- + * prescaler + * divisor = --------------------------- + * baud-rate x sampling-rate + */ static int sc16is7xx_set_baud(struct uart_port *port, int baud) { struct sc16is7xx_one *one = to_sc16is7xx_one(port, port); u8 lcr; - u8 prescaler = 0; + unsigned int prescaler = 1; unsigned long clk = port->uartclk, div = clk / 16 / baud; if (div >= BIT(16)) { - prescaler = SC16IS7XX_MCR_CLKSEL_BIT; - div /= 4; + prescaler = 4; + div /= prescaler; } /* Enable enhanced features */ @@ -573,9 +585,10 @@ static int sc16is7xx_set_baud(struct uart_port *port, int baud) SC16IS7XX_EFR_ENABLE_BIT); sc16is7xx_efr_unlock(port); + /* If bit MCR_CLKSEL is set, the divide by 4 prescaler is activated. */ sc16is7xx_port_update(port, SC16IS7XX_MCR_REG, SC16IS7XX_MCR_CLKSEL_BIT, - prescaler); + prescaler == 1 ? 0 : SC16IS7XX_MCR_CLKSEL_BIT); /* Backup LCR and access special register set (DLL/DLH) */ lcr = sc16is7xx_port_read(port, SC16IS7XX_LCR_REG); @@ -591,7 +604,7 @@ static int sc16is7xx_set_baud(struct uart_port *port, int baud) /* Restore LCR and access to general register set */ sc16is7xx_port_write(port, SC16IS7XX_LCR_REG, lcr); - return DIV_ROUND_CLOSEST(clk / 16, div); + return DIV_ROUND_CLOSEST((clk / prescaler) / 16, div); } static void sc16is7xx_handle_rx(struct uart_port *port, unsigned int rxlen,

7 months, 2 weeks

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