diff options
Diffstat (limited to 'include/linux/regset.h')
| -rw-r--r-- | include/linux/regset.h | 230 |
1 files changed, 73 insertions, 157 deletions
diff --git a/include/linux/regset.h b/include/linux/regset.h index bf0243779738..a00765f0e8cf 100644 --- a/include/linux/regset.h +++ b/include/linux/regset.h @@ -17,6 +17,64 @@ struct task_struct; struct user_regset; +struct membuf { + void *p; + size_t left; +}; + +static inline int membuf_zero(struct membuf *s, size_t size) +{ + if (s->left) { + if (size > s->left) + size = s->left; + memset(s->p, 0, size); + s->p += size; + s->left -= size; + } + return s->left; +} + +static inline int membuf_write(struct membuf *s, const void *v, size_t size) +{ + if (s->left) { + if (size > s->left) + size = s->left; + memcpy(s->p, v, size); + s->p += size; + s->left -= size; + } + return s->left; +} + +static inline struct membuf membuf_at(const struct membuf *s, size_t offs) +{ + struct membuf n = *s; + + if (offs > n.left) + offs = n.left; + n.p += offs; + n.left -= offs; + + return n; +} + +/* current s->p must be aligned for v; v must be a scalar */ +#define membuf_store(s, v) \ +({ \ + struct membuf *__s = (s); \ + if (__s->left) { \ + typeof(v) __v = (v); \ + size_t __size = sizeof(__v); \ + if (unlikely(__size > __s->left)) { \ + __size = __s->left; \ + memcpy(__s->p, &__v, __size); \ + } else { \ + *(typeof(__v + 0) *)__s->p = __v; \ + } \ + __s->p += __size; \ + __s->left -= __size; \ + } \ + __s->left;}) /** * user_regset_active_fn - type of @active function in &struct user_regset @@ -36,26 +94,9 @@ struct user_regset; typedef int user_regset_active_fn(struct task_struct *target, const struct user_regset *regset); -/** - * user_regset_get_fn - type of @get function in &struct user_regset - * @target: thread being examined - * @regset: regset being examined - * @pos: offset into the regset data to access, in bytes - * @count: amount of data to copy, in bytes - * @kbuf: if not %NULL, a kernel-space pointer to copy into - * @ubuf: if @kbuf is %NULL, a user-space pointer to copy into - * - * Fetch register values. Return %0 on success; -%EIO or -%ENODEV - * are usual failure returns. The @pos and @count values are in - * bytes, but must be properly aligned. If @kbuf is non-null, that - * buffer is used and @ubuf is ignored. If @kbuf is %NULL, then - * ubuf gives a userland pointer to access directly, and an -%EFAULT - * return value is possible. - */ -typedef int user_regset_get_fn(struct task_struct *target, +typedef int user_regset_get2_fn(struct task_struct *target, const struct user_regset *regset, - unsigned int pos, unsigned int count, - void *kbuf, void __user *ubuf); + struct membuf to); /** * user_regset_set_fn - type of @set function in &struct user_regset @@ -104,28 +145,6 @@ typedef int user_regset_writeback_fn(struct task_struct *target, int immediate); /** - * user_regset_get_size_fn - type of @get_size function in &struct user_regset - * @target: thread being examined - * @regset: regset being examined - * - * This call is optional; usually the pointer is %NULL. - * - * When provided, this function must return the current size of regset - * data, as observed by the @get function in &struct user_regset. The - * value returned must be a multiple of @size. The returned size is - * required to be valid only until the next time (if any) @regset is - * modified for @target. - * - * This function is intended for dynamically sized regsets. A regset - * that is statically sized does not need to implement it. - * - * This function should not be called directly: instead, callers should - * call regset_size() to determine the current size of a regset. - */ -typedef unsigned int user_regset_get_size_fn(struct task_struct *target, - const struct user_regset *regset); - -/** * struct user_regset - accessible thread CPU state * @n: Number of slots (registers). * @size: Size in bytes of a slot (register). @@ -136,7 +155,6 @@ typedef unsigned int user_regset_get_size_fn(struct task_struct *target, * @set: Function to store values. * @active: Function to report if regset is active, or %NULL. * @writeback: Function to write data back to user memory, or %NULL. - * @get_size: Function to return the regset's size, or %NULL. * * This data structure describes a machine resource we call a register set. * This is part of the state of an individual thread, not necessarily @@ -144,12 +162,7 @@ typedef unsigned int user_regset_get_size_fn(struct task_struct *target, * similar slots, given by @n. Each slot is @size bytes, and aligned to * @align bytes (which is at least @size). For dynamically-sized * regsets, @n must contain the maximum possible number of slots for the - * regset, and @get_size must point to a function that returns the - * current regset size. - * - * Callers that need to know only the current size of the regset and do - * not care about its internal structure should call regset_size() - * instead of inspecting @n or calling @get_size. + * regset. * * For backward compatibility, the @get and @set methods must pad to, or * accept, @n * @size bytes, even if the current regset size is smaller. @@ -185,11 +198,10 @@ typedef unsigned int user_regset_get_size_fn(struct task_struct *target, * omitted when there is an @active function and it returns zero. */ struct user_regset { - user_regset_get_fn *get; + user_regset_get2_fn *regset_get; user_regset_set_fn *set; user_regset_active_fn *active; user_regset_writeback_fn *writeback; - user_regset_get_size_fn *get_size; unsigned int n; unsigned int size; unsigned int align; @@ -238,44 +250,6 @@ 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, @@ -301,35 +275,6 @@ static inline int user_regset_copyin(unsigned int *pos, unsigned int *count, 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, @@ -353,31 +298,19 @@ static inline int user_regset_copyin_ignore(unsigned int *pos, return 0; } -/** - * copy_regset_to_user - fetch a thread's user_regset data into user memory - * @target: thread to be examined - * @view: &struct user_regset_view describing user thread machine state - * @setno: index in @view->regsets - * @offset: offset into the regset data, in bytes - * @size: amount of data to copy, in bytes - * @data: user-mode pointer to copy into - */ -static inline int copy_regset_to_user(struct task_struct *target, - const struct user_regset_view *view, - unsigned int setno, - unsigned int offset, unsigned int size, - void __user *data) -{ - const struct user_regset *regset = &view->regsets[setno]; +extern int regset_get(struct task_struct *target, + const struct user_regset *regset, + unsigned int size, void *data); - if (!regset->get) - return -EOPNOTSUPP; - - if (!access_ok(data, size)) - return -EFAULT; +extern int regset_get_alloc(struct task_struct *target, + const struct user_regset *regset, + unsigned int size, + void **data); - return regset->get(target, regset, offset, size, NULL, data); -} +extern int copy_regset_to_user(struct task_struct *target, + const struct user_regset_view *view, + unsigned int setno, unsigned int offset, + unsigned int size, void __user *data); /** * copy_regset_from_user - store into thread's user_regset data from user memory @@ -405,21 +338,4 @@ static inline int copy_regset_from_user(struct task_struct *target, return regset->set(target, regset, offset, size, NULL, data); } -/** - * regset_size - determine the current size of a regset - * @target: thread to be examined - * @regset: regset to be examined - * - * Note that the returned size is valid only until the next time - * (if any) @regset is modified for @target. - */ -static inline unsigned int regset_size(struct task_struct *target, - const struct user_regset *regset) -{ - if (!regset->get_size) - return regset->n * regset->size; - else - return regset->get_size(target, regset); -} - #endif /* <linux/regset.h> */ |