summaryrefslogtreecommitdiff
path: root/arch/x86/include/asm/uaccess.h
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2023-05-03 02:39:59 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2023-05-03 20:37:22 +0300
commitb9bd9f605c4a6f04a83e6640a7d1d6dda80f17ca (patch)
tree30790cb30af3d655b84b933a5175a4490d5b035b /arch/x86/include/asm/uaccess.h
parent6ccdc91d6af922f3ded5de494ff27daedeb6d6c9 (diff)
downloadlinux-b9bd9f605c4a6f04a83e6640a7d1d6dda80f17ca.tar.xz
x86: uaccess: move 32-bit and 64-bit parts into proper <asm/uaccess_N.h> header
The x86 <asm/uaccess.h> file has grown features that are specific to x86-64 like LAM support and the related access_ok() changes. They really should be in the <asm/uaccess_64.h> file and not pollute the generic x86 header. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/x86/include/asm/uaccess.h')
-rw-r--r--arch/x86/include/asm/uaccess.h87
1 files changed, 3 insertions, 84 deletions
diff --git a/arch/x86/include/asm/uaccess.h b/arch/x86/include/asm/uaccess.h
index cad17e11aa83..8bae40a66282 100644
--- a/arch/x86/include/asm/uaccess.h
+++ b/arch/x86/include/asm/uaccess.h
@@ -16,83 +16,10 @@
#include <asm/extable.h>
#include <asm/tlbflush.h>
-#ifdef CONFIG_ADDRESS_MASKING
-/*
- * Mask out tag bits from the address.
- *
- * Magic with the 'sign' allows to untag userspace pointer without any branches
- * while leaving kernel addresses intact.
- */
-static inline unsigned long __untagged_addr(unsigned long addr)
-{
- long sign;
-
- /*
- * Refer tlbstate_untag_mask directly to avoid RIP-relative relocation
- * in alternative instructions. The relocation gets wrong when gets
- * copied to the target place.
- */
- asm (ALTERNATIVE("",
- "sar $63, %[sign]\n\t" /* user_ptr ? 0 : -1UL */
- "or %%gs:tlbstate_untag_mask, %[sign]\n\t"
- "and %[sign], %[addr]\n\t", X86_FEATURE_LAM)
- : [addr] "+r" (addr), [sign] "=r" (sign)
- : "m" (tlbstate_untag_mask), "[sign]" (addr));
-
- return addr;
-}
-
-#define untagged_addr(addr) ({ \
- unsigned long __addr = (__force unsigned long)(addr); \
- (__force __typeof__(addr))__untagged_addr(__addr); \
-})
-
-static inline unsigned long __untagged_addr_remote(struct mm_struct *mm,
- unsigned long addr)
-{
- long sign = addr >> 63;
-
- mmap_assert_locked(mm);
- addr &= (mm)->context.untag_mask | sign;
-
- return addr;
-}
-
-#define untagged_addr_remote(mm, addr) ({ \
- unsigned long __addr = (__force unsigned long)(addr); \
- (__force __typeof__(addr))__untagged_addr_remote(mm, __addr); \
-})
-
+#ifdef CONFIG_X86_32
+# include <asm/uaccess_32.h>
#else
-#define untagged_addr(addr) (addr)
-#endif
-
-#ifdef CONFIG_X86_64
-/*
- * On x86-64, we may have tag bits in the user pointer. Rather than
- * mask them off, just change the rules for __access_ok().
- *
- * Make the rule be that 'ptr+size' must not overflow, and must not
- * have the high bit set. Compilers generally understand about
- * unsigned overflow and the CF bit and generate reasonable code for
- * this. Although it looks like the combination confuses at least
- * clang (and instead of just doing an "add" followed by a test of
- * SF and CF, you'll see that unnecessary comparison).
- *
- * For the common case of small sizes that can be checked at compile
- * time, don't even bother with the addition, and just check that the
- * base pointer is ok.
- */
-static inline bool __access_ok(const void __user *ptr, unsigned long size)
-{
- if (__builtin_constant_p(size <= PAGE_SIZE) && size <= PAGE_SIZE) {
- return (long)ptr >= 0;
- } else {
- unsigned long sum = size + (unsigned long)ptr;
- return (long) sum >= 0 && sum >= (unsigned long)ptr;
- }
-}
-#define __access_ok __access_ok
+# include <asm/uaccess_64.h>
#endif
#include <asm-generic/access_ok.h>
@@ -583,14 +510,6 @@ extern struct movsl_mask {
#define ARCH_HAS_NOCACHE_UACCESS 1
-#ifdef CONFIG_X86_32
-unsigned long __must_check clear_user(void __user *mem, unsigned long len);
-unsigned long __must_check __clear_user(void __user *mem, unsigned long len);
-# include <asm/uaccess_32.h>
-#else
-# include <asm/uaccess_64.h>
-#endif
-
/*
* The "unsafe" user accesses aren't really "unsafe", but the naming
* is a big fat warning: you have to not only do the access_ok()