Commit d99dc586 authored by Yury Norov (NVIDIA)'s avatar Yury Norov (NVIDIA) Committed by Andrew Morton
Browse files

uaccess: decouple INLINE_COPY_FROM_USER and CONFIG_RUST 

Commit 1f9a8286 ("uaccess: always export _copy_[from|to]_user with
CONFIG_RUST") exports _copy_{from,to}_user() unconditionally, if RUST is
enabled.  This pollutes exported symbols namespace, and spreads RUST
ifdefery in core files.

It's better to declare a corresponding helper under the rust/helpers,
similarly to how non-underscored copy_{from,to}_user() is handled.

[yury.norov@gmail.com: drop rust part of comment for _copy_from_user(), per Alice]
  Link: https://lkml.kernel.org/r/20251024154754.99768-1-yury.norov@gmail.com
Link: https://lkml.kernel.org/r/20251023171607.1171534-1-yury.norov@gmail.com


Signed-off-by: default avatarYury Norov (NVIDIA) <yury.norov@gmail.com>
Acked-by: default avatarArnd Bergmann <arnd@arndb.de>
Acked-by: default avatarMiguel Ojeda <ojeda@kernel.org>
Reviewed-by: default avatarAlice Ryhl <aliceryhl@google.com>
Tested-by: default avatarAlice Ryhl <aliceryhl@google.com>
Cc: Alex Gaynor <alex.gaynor@gmail.com>
Cc: Andreas Hindborg <a.hindborg@kernel.org>
Cc: Björn Roy Baron <bjorn3_gh@protonmail.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Danilo Krummrich <dakr@kernel.org>
Cc: Gary Guo <gary@garyguo.net>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Trevor Gross <tmgross@umich.edu>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 032a7302

include/linux/uaccess.h

+0 −2
Original line number Diff line number Diff line
@@ -152,8 +152,6 @@ __copy_to_user(void __user *to, const void *from, unsigned long n) 
 * directly in the normal copy_to/from_user(), the other ones go

 * through an extern _copy_to/from_user(), which expands the same code

 * here.

 *

 * Rust code always uses the extern definition.

 */

static inline __must_check unsigned long

_inline_copy_from_user(void *to, const void __user *from, unsigned long n)

lib/usercopy.c

+2 −2
Original line number Diff line number Diff line
@@ -12,7 +12,7 @@ 


/* out-of-line parts */



#if !defined(INLINE_COPY_FROM_USER) || defined(CONFIG_RUST)

#if !defined(INLINE_COPY_FROM_USER)

unsigned long _copy_from_user(void *to, const void __user *from, unsigned long n)

{

	return _inline_copy_from_user(to, from, n);
@@ -20,7 +20,7 @@ unsigned long _copy_from_user(void *to, const void __user *from, unsigned long n 
EXPORT_SYMBOL(_copy_from_user);

#endif



#if !defined(INLINE_COPY_TO_USER) || defined(CONFIG_RUST)

#if !defined(INLINE_COPY_TO_USER)

unsigned long _copy_to_user(void __user *to, const void *from, unsigned long n)

{

	return _inline_copy_to_user(to, from, n);

rust/helpers/uaccess.c

+12 −0
Original line number Diff line number Diff line
@@ -13,3 +13,15 @@ unsigned long rust_helper_copy_to_user(void __user *to, const void *from, 
{

	return copy_to_user(to, from, n);

}



#ifdef INLINE_COPY_FROM_USER

unsigned long rust_helper__copy_from_user(void *to, const void __user *from, unsigned long n)

{

	return _inline_copy_from_user(to, from, n);

}



unsigned long rust_helper__copy_to_user(void __user *to, const void *from, unsigned long n)

{

	return _inline_copy_to_user(to, from, n);

}

#endif