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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-07-01 17:13:56 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-07-01 17:13:56 +0000 |
commit | 511e4ecd3211371086a9698ce4042700957cee33 (patch) | |
tree | 7e4c8dbd3f81844f362f480dd8c9244afd9e31dc /drivers/input/input.c | |
parent | Adding debian version 6.9.2-1~exp1. (diff) | |
download | linux-511e4ecd3211371086a9698ce4042700957cee33.tar.xz linux-511e4ecd3211371086a9698ce4042700957cee33.zip |
Merging upstream version 6.9.7.
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/input/input.c')
-rw-r--r-- | drivers/input/input.c | 104 |
1 files changed, 89 insertions, 15 deletions
diff --git a/drivers/input/input.c b/drivers/input/input.c index 7114854375..fd4997ba26 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; |