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Merge tag 'asm-generic-nommu' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic

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Pull nommu generic uaccess updates from Arnd Bergmann:
 "asm-generic: kill <asm/segment.h> and improve nommu generic uaccess helpers

  Christoph Hellwig writes:

     This is a series doing two somewhat interwinded things. It improves
     the asm-generic nommu uaccess helper to optionally be entirely
     generic and not require any arch helpers for the actual uaccess.
     For the generic uaccess.h to actually be generically useful I also
     had to kill off the mess we made of <asm/segment.h>, which really
     shouldn't exist on most architectures"

* tag 'asm-generic-nommu' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic:
  asm-generic: optimize generic uaccess for 8-byte loads and stores
  asm-generic: provide entirely generic nommu uaccess
  arch: mostly remove <asm/segment.h>
  asm-generic: don't include <asm/segment.h> from <asm/uaccess.h>
This commit is contained in:
Linus Torvalds
2019-05-16 11:26:37 -07:00
parent d396360acd 6edd1dbace
commit 27ebbf9d5b
30 changed files with 64 additions and 117 deletions
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9
include/asm-generic/segment.h
View File

@@ -1,9 +0,0 @@
#ifndef __ASM_GENERIC_SEGMENT_H
#define __ASM_GENERIC_SEGMENT_H
/*
* Only here because we have some old header files that expect it...
*
* New architectures probably don't want to have their own version.
*/
#endif /* __ASM_GENERIC_SEGMENT_H */

58
include/asm-generic/uaccess.h
View File

@@ -9,7 +9,63 @@
*/
#include <linux/string.h>
#include <asm/segment.h>
#ifdef CONFIG_UACCESS_MEMCPY
static inline __must_check unsigned long
raw_copy_from_user(void *to, const void __user * from, unsigned long n)
{
if (__builtin_constant_p(n)) {
switch(n) {
case 1:
*(u8 *)to = *(u8 __force *)from;
return 0;
case 2:
*(u16 *)to = *(u16 __force *)from;
return 0;
case 4:
*(u32 *)to = *(u32 __force *)from;
return 0;
#ifdef CONFIG_64BIT
case 8:
*(u64 *)to = *(u64 __force *)from;
return 0;
#endif
}
}
memcpy(to, (const void __force *)from, n);
return 0;
}
static inline __must_check unsigned long
raw_copy_to_user(void __user *to, const void *from, unsigned long n)
{
if (__builtin_constant_p(n)) {
switch(n) {
case 1:
*(u8 __force *)to = *(u8 *)from;
return 0;
case 2:
*(u16 __force *)to = *(u16 *)from;
return 0;
case 4:
*(u32 __force *)to = *(u32 *)from;
return 0;
#ifdef CONFIG_64BIT
case 8:
*(u64 __force *)to = *(u64 *)from;
return 0;
#endif
default:
break;
}
}
memcpy((void __force *)to, from, n);
return 0;
}
#define INLINE_COPY_FROM_USER
#define INLINE_COPY_TO_USER
#endif /* CONFIG_UACCESS_MEMCPY */
#define MAKE_MM_SEG(s) ((mm_segment_t) { (s) })