/* * User-mode machine state access * * Copyright (C) 2007 Red Hat, Inc. All rights reserved. * * This copyrighted material is made available to anyone wishing to use, * modify, copy, or redistribute it subject to the terms and conditions * of the GNU General Public License v.2. * * Red Hat Author: Roland McGrath. */ #ifndef _LINUX_REGSET_H #define _LINUX_REGSET_H 1 #include #include #include #include struct task_struct; struct user_regset; typedef int user_regset_active_fn(struct task_struct *target, const struct user_regset *regset); typedef int user_regset_get_fn(struct task_struct *target, const struct user_regset *regset, unsigned int pos, unsigned int count, void *kbuf, void __user *ubuf); typedef int user_regset_set_fn(struct task_struct *target, const struct user_regset *regset, unsigned int pos, unsigned int count, const void *kbuf, const void __user *ubuf); /** * user_regset_writeback_fn - type of @writeback function in &struct user_regset * @target: thread being examined * @regset: regset being examined * @immediate: zero if writeback at completion of next context switch is OK * * This call is optional; usually the pointer is %NULL. When * provided, there is some user memory associated with this regset's * hardware, such as memory backing cached register data on register * window machines; the regset's data controls what user memory is * used (e.g. via the stack pointer value). * * Write register data back to user memory. If the @immediate flag * is nonzero, it must be written to the user memory so uaccess or * access_process_vm() can see it when this call returns; if zero, * then it must be written back by the time the task completes a * context switch (as synchronized with wait_task_inactive()). * Return %0 on success or if there was nothing to do, -%EFAULT for * a memory problem (bad stack pointer or whatever), or -%EIO for a * hardware problem. */ typedef int user_regset_writeback_fn(struct task_struct *target, const struct user_regset *regset, int immediate); struct user_regset { user_regset_get_fn *get; user_regset_set_fn *set; user_regset_active_fn *active; user_regset_writeback_fn *writeback; unsigned int n; unsigned int size; unsigned int align; unsigned int bias; unsigned int core_note_type; }; /** * struct user_regset_view - available regsets * @name: Identifier, e.g. UTS_MACHINE string. * @regsets: Array of @n regsets available in this view. * @n: Number of elements in @regsets. * @e_machine: ELF header @e_machine %EM_* value written in core dumps. * @e_flags: ELF header @e_flags value written in core dumps. * @ei_osabi: ELF header @e_ident[%EI_OSABI] value written in core dumps. * * A regset view is a collection of regsets (&struct user_regset, * above). This describes all the state of a thread that can be seen * from a given architecture/ABI environment. More than one view might * refer to the same &struct user_regset, or more than one regset * might refer to the same machine-specific state in the thread. For * example, a 32-bit thread's state could be examined from the 32-bit * view or from the 64-bit view. Either method reaches the same thread * register state, doing appropriate widening or truncation. */ struct user_regset_view { const char *name; const struct user_regset *regsets; unsigned int n; u32 e_flags; u16 e_machine; u8 ei_osabi; }; const struct user_regset_view *task_user_regset_view(struct task_struct *tsk); 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; } 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; } 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]; if (!regset->get) return -EOPNOTSUPP; if (!access_ok(VERIFY_WRITE, data, size)) return -EFAULT; return regset->get(target, regset, offset, size, NULL, data); } static inline int copy_regset_from_user(struct task_struct *target, const struct user_regset_view *view, unsigned int setno, unsigned int offset, unsigned int size, const void __user *data) { const struct user_regset *regset = &view->regsets[setno]; if (!regset->set) return -EOPNOTSUPP; if (!access_ok(VERIFY_READ, data, size)) return -EFAULT; return regset->set(target, regset, offset, size, NULL, data); } #endif