diff options
| -rw-r--r-- | drivers/char/nvram.c | 120 | ||||
| -rw-r--r-- | include/linux/nvram.h | 32 |
2 files changed, 104 insertions, 48 deletions
diff --git a/drivers/char/nvram.c b/drivers/char/nvram.c index f88ef41d0598..adcc213c331e 100644 --- a/drivers/char/nvram.c +++ b/drivers/char/nvram.c @@ -41,6 +41,7 @@ #include <linux/init.h> #include <linux/proc_fs.h> #include <linux/seq_file.h> +#include <linux/slab.h> #include <linux/spinlock.h> #include <linux/io.h> #include <linux/uaccess.h> @@ -161,7 +162,46 @@ static ssize_t pc_nvram_get_size(void) return NVRAM_BYTES; } +static ssize_t pc_nvram_read(char *buf, size_t count, loff_t *ppos) +{ + char *p = buf; + loff_t i; + + spin_lock_irq(&rtc_lock); + if (!__nvram_check_checksum()) { + spin_unlock_irq(&rtc_lock); + return -EIO; + } + for (i = *ppos; count > 0 && i < NVRAM_BYTES; --count, ++i, ++p) + *p = __nvram_read_byte(i); + spin_unlock_irq(&rtc_lock); + + *ppos = i; + return p - buf; +} + +static ssize_t pc_nvram_write(char *buf, size_t count, loff_t *ppos) +{ + char *p = buf; + loff_t i; + + spin_lock_irq(&rtc_lock); + if (!__nvram_check_checksum()) { + spin_unlock_irq(&rtc_lock); + return -EIO; + } + for (i = *ppos; count > 0 && i < NVRAM_BYTES; --count, ++i, ++p) + __nvram_write_byte(*p, i); + __nvram_set_checksum(); + spin_unlock_irq(&rtc_lock); + + *ppos = i; + return p - buf; +} + const struct nvram_ops arch_nvram_ops = { + .read = pc_nvram_read, + .write = pc_nvram_write, .read_byte = pc_nvram_read_byte, .write_byte = pc_nvram_write_byte, .get_size = pc_nvram_get_size, @@ -184,69 +224,57 @@ static loff_t nvram_misc_llseek(struct file *file, loff_t offset, int origin) static ssize_t nvram_misc_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) { - unsigned char contents[NVRAM_BYTES]; - unsigned i = *ppos; - unsigned char *tmp; - - spin_lock_irq(&rtc_lock); + char *tmp; + ssize_t ret; - if (!__nvram_check_checksum()) - goto checksum_err; - for (tmp = contents; count-- > 0 && i < NVRAM_BYTES; ++i, ++tmp) - *tmp = __nvram_read_byte(i); + if (!access_ok(buf, count)) + return -EFAULT; + if (*ppos >= nvram_size) + return 0; - spin_unlock_irq(&rtc_lock); + count = min_t(size_t, count, nvram_size - *ppos); + count = min_t(size_t, count, PAGE_SIZE); - if (copy_to_user(buf, contents, tmp - contents)) - return -EFAULT; + tmp = kmalloc(count, GFP_KERNEL); + if (!tmp) + return -ENOMEM; - *ppos = i; + ret = nvram_read(tmp, count, ppos); + if (ret <= 0) + goto out; - return tmp - contents; + if (copy_to_user(buf, tmp, ret)) { + *ppos -= ret; + ret = -EFAULT; + } -checksum_err: - spin_unlock_irq(&rtc_lock); - return -EIO; +out: + kfree(tmp); + return ret; } static ssize_t nvram_misc_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) { - unsigned char contents[NVRAM_BYTES]; - unsigned i = *ppos; - unsigned char *tmp; - - if (i >= NVRAM_BYTES) - return 0; /* Past EOF */ - - if (count > NVRAM_BYTES - i) - count = NVRAM_BYTES - i; - if (count > NVRAM_BYTES) - return -EFAULT; /* Can't happen, but prove it to gcc */ + char *tmp; + ssize_t ret; - if (copy_from_user(contents, buf, count)) + if (!access_ok(buf, count)) return -EFAULT; + if (*ppos >= nvram_size) + return 0; - spin_lock_irq(&rtc_lock); - - if (!__nvram_check_checksum()) - goto checksum_err; - - for (tmp = contents; count--; ++i, ++tmp) - __nvram_write_byte(*tmp, i); + count = min_t(size_t, count, nvram_size - *ppos); + count = min_t(size_t, count, PAGE_SIZE); - __nvram_set_checksum(); - - spin_unlock_irq(&rtc_lock); + tmp = memdup_user(buf, count); + if (IS_ERR(tmp)) + return PTR_ERR(tmp); - *ppos = i; - - return tmp - contents; - -checksum_err: - spin_unlock_irq(&rtc_lock); - return -EIO; + ret = nvram_write(tmp, count, ppos); + kfree(tmp); + return ret; } static long nvram_misc_ioctl(struct file *file, unsigned int cmd, diff --git a/include/linux/nvram.h b/include/linux/nvram.h index 31c763087746..9df85703735c 100644 --- a/include/linux/nvram.h +++ b/include/linux/nvram.h @@ -66,18 +66,46 @@ static inline void nvram_write_byte(unsigned char val, int addr) #endif } +static inline ssize_t nvram_read_bytes(char *buf, size_t count, loff_t *ppos) +{ + ssize_t nvram_size = nvram_get_size(); + loff_t i; + char *p = buf; + + if (nvram_size < 0) + return nvram_size; + for (i = *ppos; count > 0 && i < nvram_size; ++i, ++p, --count) + *p = nvram_read_byte(i); + *ppos = i; + return p - buf; +} + +static inline ssize_t nvram_write_bytes(char *buf, size_t count, loff_t *ppos) +{ + ssize_t nvram_size = nvram_get_size(); + loff_t i; + char *p = buf; + + if (nvram_size < 0) + return nvram_size; + for (i = *ppos; count > 0 && i < nvram_size; ++i, ++p, --count) + nvram_write_byte(*p, i); + *ppos = i; + return p - buf; +} + static inline ssize_t nvram_read(char *buf, size_t count, loff_t *ppos) { if (arch_nvram_ops.read) return arch_nvram_ops.read(buf, count, ppos); - return -ENODEV; + return nvram_read_bytes(buf, count, ppos); } static inline ssize_t nvram_write(char *buf, size_t count, loff_t *ppos) { if (arch_nvram_ops.write) return arch_nvram_ops.write(buf, count, ppos); - return -ENODEV; + return nvram_write_bytes(buf, count, ppos); } #endif /* _LINUX_NVRAM_H */ |