diff options
| author | Kirill A. Shutemov <kirill.shutemov@linux.intel.com> | 2025-03-04 17:33:42 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2025-03-19 11:26:24 +0100 |
| commit | bd72baff229920da1d57c14364c11ecdbaf5b458 (patch) | |
| tree | e4628d42e9d4ab8d38dbe9bccac09caa9620d8e8 | |
| parent | fadb6f569b10bf668677add876ed50586931b8f3 (diff) | |
x86/runtime-const: Add the RUNTIME_CONST_PTR assembly macro
Add an assembly macro to refer runtime cost. It hides linker magic and
makes assembly more readable.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/20250304153342.2016569-1-kirill.shutemov@linux.intel.com
| -rw-r--r-- | arch/x86/include/asm/runtime-const.h | 13 | ||||
| -rw-r--r-- | arch/x86/lib/getuser.S | 7 |
2 files changed, 15 insertions, 5 deletions
diff --git a/arch/x86/include/asm/runtime-const.h b/arch/x86/include/asm/runtime-const.h index 6652ebddfd02..8d983cfd06ea 100644 --- a/arch/x86/include/asm/runtime-const.h +++ b/arch/x86/include/asm/runtime-const.h @@ -2,6 +2,18 @@ #ifndef _ASM_RUNTIME_CONST_H #define _ASM_RUNTIME_CONST_H +#ifdef __ASSEMBLY__ + +.macro RUNTIME_CONST_PTR sym reg + movq $0x0123456789abcdef, %\reg + 1: + .pushsection runtime_ptr_\sym, "a" + .long 1b - 8 - . + .popsection +.endm + +#else /* __ASSEMBLY__ */ + #define runtime_const_ptr(sym) ({ \ typeof(sym) __ret; \ asm_inline("mov %1,%0\n1:\n" \ @@ -58,4 +70,5 @@ static inline void runtime_const_fixup(void (*fn)(void *, unsigned long), } } +#endif /* __ASSEMBLY__ */ #endif diff --git a/arch/x86/lib/getuser.S b/arch/x86/lib/getuser.S index 71d8e7da4fc5..9d5654b8a72a 100644 --- a/arch/x86/lib/getuser.S +++ b/arch/x86/lib/getuser.S @@ -35,16 +35,13 @@ #include <asm/thread_info.h> #include <asm/asm.h> #include <asm/smap.h> +#include <asm/runtime-const.h> #define ASM_BARRIER_NOSPEC ALTERNATIVE "", "lfence", X86_FEATURE_LFENCE_RDTSC .macro check_range size:req .if IS_ENABLED(CONFIG_X86_64) - movq $0x0123456789abcdef,%rdx - 1: - .pushsection runtime_ptr_USER_PTR_MAX,"a" - .long 1b - 8 - . - .popsection + RUNTIME_CONST_PTR USER_PTR_MAX, rdx cmp %rdx, %rax cmova %rdx, %rax .else |