diff options
| author | Thomas Gleixner <tglx@linutronix.de> | 2025-10-27 09:43:56 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2025-11-04 08:28:15 +0100 |
| commit | b2cfc0cd68b830dde80fce2406580e258a1e976d (patch) | |
| tree | bfb76a2eb166ead2cc4f900333289d6b8d189074 | |
| parent | e497310b4ffb559e1149ee89470d5c518d234ddf (diff) | |
uaccess: Provide put/get_user_inline()
Provide convenience wrappers around scoped user access similar to
put/get_user(), which reduce the usage sites to:
if (!get_user_inline(val, ptr))
return -EFAULT;
Should only be used if there is a demonstrable performance benefit.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://patch.msgid.link/20251027083745.609031602@linutronix.de
| -rw-r--r-- | include/linux/uaccess.h | 50 |
1 files changed, 50 insertions, 0 deletions
diff --git a/include/linux/uaccess.h b/include/linux/uaccess.h index 5f142c05b0dc..be395f5f7ee3 100644 --- a/include/linux/uaccess.h +++ b/include/linux/uaccess.h @@ -825,6 +825,56 @@ for (bool done = false; !done; done = true) \ #define scoped_user_rw_access(uptr, elbl) \ scoped_user_rw_access_size(uptr, sizeof(*(uptr)), elbl) +/** + * get_user_inline - Read user data inlined + * @val: The variable to store the value read from user memory + * @usrc: Pointer to the user space memory to read from + * + * Return: 0 if successful, -EFAULT when faulted + * + * Inlined variant of get_user(). Only use when there is a demonstrable + * performance reason. + */ +#define get_user_inline(val, usrc) \ +({ \ + __label__ efault; \ + typeof(usrc) _tmpsrc = usrc; \ + int _ret = 0; \ + \ + scoped_user_read_access(_tmpsrc, efault) \ + unsafe_get_user(val, _tmpsrc, efault); \ + if (0) { \ + efault: \ + _ret = -EFAULT; \ + } \ + _ret; \ +}) + +/** + * put_user_inline - Write to user memory inlined + * @val: The value to write + * @udst: Pointer to the user space memory to write to + * + * Return: 0 if successful, -EFAULT when faulted + * + * Inlined variant of put_user(). Only use when there is a demonstrable + * performance reason. + */ +#define put_user_inline(val, udst) \ +({ \ + __label__ efault; \ + typeof(udst) _tmpdst = udst; \ + int _ret = 0; \ + \ + scoped_user_write_access(_tmpdst, efault) \ + unsafe_put_user(val, _tmpdst, efault); \ + if (0) { \ + efault: \ + _ret = -EFAULT; \ + } \ + _ret; \ +}) + #ifdef CONFIG_HARDENED_USERCOPY void __noreturn usercopy_abort(const char *name, const char *detail, bool to_user, unsigned long offset, |