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authorAl Viro <viro@zeniv.linux.org.uk>2020-02-15 19:46:30 +0300
committerAl Viro <viro@zeniv.linux.org.uk>2020-03-18 22:53:25 +0300
commit4b842e4e25b12951fa10dedb4bc16bc47e3b850c (patch)
treef8ef35539d2ff303275d19182770732d4e053d0e /arch/x86/include/asm/uaccess_64.h
parent71c3313a38aa09339a2442809e658fd233ab0757 (diff)
downloadlinux-4b842e4e25b12951fa10dedb4bc16bc47e3b850c.tar.xz
x86: get rid of small constant size cases in raw_copy_{to,from}_user()
Very few call sites where that would be triggered remain, and none of those is anywhere near hot enough to bother. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'arch/x86/include/asm/uaccess_64.h')
-rw-r--r--arch/x86/include/asm/uaccess_64.h108
1 files changed, 2 insertions, 106 deletions
diff --git a/arch/x86/include/asm/uaccess_64.h b/arch/x86/include/asm/uaccess_64.h
index 5cd1caa8bc65..bc10e3dc64fe 100644
--- a/arch/x86/include/asm/uaccess_64.h
+++ b/arch/x86/include/asm/uaccess_64.h
@@ -65,117 +65,13 @@ copy_to_user_mcsafe(void *to, const void *from, unsigned len)
static __always_inline __must_check unsigned long
raw_copy_from_user(void *dst, const void __user *src, unsigned long size)
{
- int ret = 0;
-
- if (!__builtin_constant_p(size))
- return copy_user_generic(dst, (__force void *)src, size);
- switch (size) {
- case 1:
- __uaccess_begin_nospec();
- __get_user_asm_nozero(*(u8 *)dst, (u8 __user *)src,
- ret, "b", "b", "=q", 1);
- __uaccess_end();
- return ret;
- case 2:
- __uaccess_begin_nospec();
- __get_user_asm_nozero(*(u16 *)dst, (u16 __user *)src,
- ret, "w", "w", "=r", 2);
- __uaccess_end();
- return ret;
- case 4:
- __uaccess_begin_nospec();
- __get_user_asm_nozero(*(u32 *)dst, (u32 __user *)src,
- ret, "l", "k", "=r", 4);
- __uaccess_end();
- return ret;
- case 8:
- __uaccess_begin_nospec();
- __get_user_asm_nozero(*(u64 *)dst, (u64 __user *)src,
- ret, "q", "", "=r", 8);
- __uaccess_end();
- return ret;
- case 10:
- __uaccess_begin_nospec();
- __get_user_asm_nozero(*(u64 *)dst, (u64 __user *)src,
- ret, "q", "", "=r", 10);
- if (likely(!ret))
- __get_user_asm_nozero(*(u16 *)(8 + (char *)dst),
- (u16 __user *)(8 + (char __user *)src),
- ret, "w", "w", "=r", 2);
- __uaccess_end();
- return ret;
- case 16:
- __uaccess_begin_nospec();
- __get_user_asm_nozero(*(u64 *)dst, (u64 __user *)src,
- ret, "q", "", "=r", 16);
- if (likely(!ret))
- __get_user_asm_nozero(*(u64 *)(8 + (char *)dst),
- (u64 __user *)(8 + (char __user *)src),
- ret, "q", "", "=r", 8);
- __uaccess_end();
- return ret;
- default:
- return copy_user_generic(dst, (__force void *)src, size);
- }
+ return copy_user_generic(dst, (__force void *)src, size);
}
static __always_inline __must_check unsigned long
raw_copy_to_user(void __user *dst, const void *src, unsigned long size)
{
- int ret = 0;
-
- if (!__builtin_constant_p(size))
- return copy_user_generic((__force void *)dst, src, size);
- switch (size) {
- case 1:
- __uaccess_begin();
- __put_user_asm(*(u8 *)src, (u8 __user *)dst,
- ret, "b", "b", "iq", 1);
- __uaccess_end();
- return ret;
- case 2:
- __uaccess_begin();
- __put_user_asm(*(u16 *)src, (u16 __user *)dst,
- ret, "w", "w", "ir", 2);
- __uaccess_end();
- return ret;
- case 4:
- __uaccess_begin();
- __put_user_asm(*(u32 *)src, (u32 __user *)dst,
- ret, "l", "k", "ir", 4);
- __uaccess_end();
- return ret;
- case 8:
- __uaccess_begin();
- __put_user_asm(*(u64 *)src, (u64 __user *)dst,
- ret, "q", "", "er", 8);
- __uaccess_end();
- return ret;
- case 10:
- __uaccess_begin();
- __put_user_asm(*(u64 *)src, (u64 __user *)dst,
- ret, "q", "", "er", 10);
- if (likely(!ret)) {
- asm("":::"memory");
- __put_user_asm(4[(u16 *)src], 4 + (u16 __user *)dst,
- ret, "w", "w", "ir", 2);
- }
- __uaccess_end();
- return ret;
- case 16:
- __uaccess_begin();
- __put_user_asm(*(u64 *)src, (u64 __user *)dst,
- ret, "q", "", "er", 16);
- if (likely(!ret)) {
- asm("":::"memory");
- __put_user_asm(1[(u64 *)src], 1 + (u64 __user *)dst,
- ret, "q", "", "er", 8);
- }
- __uaccess_end();
- return ret;
- default:
- return copy_user_generic((__force void *)dst, src, size);
- }
+ return copy_user_generic((__force void *)dst, src, size);
}
static __always_inline __must_check