diff options
| -rw-r--r-- | include/linux/regset.h | 116 |
1 files changed, 116 insertions, 0 deletions
diff --git a/include/linux/regset.h b/include/linux/regset.h index 85d0fb0a014d..761c931af975 100644 --- a/include/linux/regset.h +++ b/include/linux/regset.h @@ -15,6 +15,7 @@ #include <linux/compiler.h> #include <linux/types.h> +#include <linux/uaccess.h> struct task_struct; struct user_regset; @@ -203,4 +204,119 @@ struct user_regset_view { const struct user_regset_view *task_user_regset_view(struct task_struct *tsk); +/* + * These are helpers for writing regset get/set functions in arch code. + * Because @start_pos and @end_pos are always compile-time constants, + * these are inlined into very little code though they look large. + * + * Use one or more calls sequentially for each chunk of regset data stored + * contiguously in memory. Call with constants for @start_pos and @end_pos, + * giving the range of byte positions in the regset that data corresponds + * to; @end_pos can be -1 if this chunk is at the end of the regset layout. + * Each call updates the arguments to point past its chunk. + */ + +static inline int user_regset_copyout(unsigned int *pos, unsigned int *count, + void **kbuf, + void __user **ubuf, const void *data, + const int start_pos, const int end_pos) +{ + if (*count == 0) + return 0; + BUG_ON(*pos < start_pos); + if (end_pos < 0 || *pos < end_pos) { + unsigned int copy = (end_pos < 0 ? *count + : min(*count, end_pos - *pos)); + data += *pos - start_pos; + if (*kbuf) { + memcpy(*kbuf, data, copy); + *kbuf += copy; + } else if (__copy_to_user(*ubuf, data, copy)) + return -EFAULT; + else + *ubuf += copy; + *pos += copy; + *count -= copy; + } + return 0; +} + +static inline int user_regset_copyin(unsigned int *pos, unsigned int *count, + const void **kbuf, + const void __user **ubuf, void *data, + const int start_pos, const int end_pos) +{ + if (*count == 0) + return 0; + BUG_ON(*pos < start_pos); + if (end_pos < 0 || *pos < end_pos) { + unsigned int copy = (end_pos < 0 ? *count + : min(*count, end_pos - *pos)); + data += *pos - start_pos; + if (*kbuf) { + memcpy(data, *kbuf, copy); + *kbuf += copy; + } else if (__copy_from_user(data, *ubuf, copy)) + return -EFAULT; + else + *ubuf += copy; + *pos += copy; + *count -= copy; + } + return 0; +} + +/* + * These two parallel the two above, but for portions of a regset layout + * that always read as all-zero or for which writes are ignored. + */ +static inline int user_regset_copyout_zero(unsigned int *pos, + unsigned int *count, + void **kbuf, void __user **ubuf, + const int start_pos, + const int end_pos) +{ + if (*count == 0) + return 0; + BUG_ON(*pos < start_pos); + if (end_pos < 0 || *pos < end_pos) { + unsigned int copy = (end_pos < 0 ? *count + : min(*count, end_pos - *pos)); + if (*kbuf) { + memset(*kbuf, 0, copy); + *kbuf += copy; + } else if (__clear_user(*ubuf, copy)) + return -EFAULT; + else + *ubuf += copy; + *pos += copy; + *count -= copy; + } + return 0; +} + +static inline int user_regset_copyin_ignore(unsigned int *pos, + unsigned int *count, + const void **kbuf, + const void __user **ubuf, + const int start_pos, + const int end_pos) +{ + if (*count == 0) + return 0; + BUG_ON(*pos < start_pos); + if (end_pos < 0 || *pos < end_pos) { + unsigned int copy = (end_pos < 0 ? *count + : min(*count, end_pos - *pos)); + if (*kbuf) + *kbuf += copy; + else + *ubuf += copy; + *pos += copy; + *count -= copy; + } + return 0; +} + + #endif /* <linux/regset.h> */ |