diff options
Diffstat (limited to 'arch/x86/include/asm/vdso/sys_call.h')
| -rw-r--r-- | arch/x86/include/asm/vdso/sys_call.h | 105 |
1 files changed, 105 insertions, 0 deletions
diff --git a/arch/x86/include/asm/vdso/sys_call.h b/arch/x86/include/asm/vdso/sys_call.h new file mode 100644 index 000000000000..5806b1cd6aef --- /dev/null +++ b/arch/x86/include/asm/vdso/sys_call.h @@ -0,0 +1,105 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Macros for issuing an inline system call from the vDSO. + */ + +#ifndef X86_ASM_VDSO_SYS_CALL_H +#define X86_ASM_VDSO_SYS_CALL_H + +#include <linux/compiler.h> +#include <asm/cpufeatures.h> +#include <asm/alternative.h> + +#ifdef CONFIG_X86_64 +# define __sys_instr "syscall" +# define __sys_clobber "rcx", "r11", "memory" +# define __sys_nr(x,y) __NR_ ## x +# define __sys_reg1 "rdi" +# define __sys_reg2 "rsi" +# define __sys_reg3 "rdx" +# define __sys_reg4 "r10" +# define __sys_reg5 "r8" +#else +# define __sys_instr ALTERNATIVE("ds;ds;ds;int $0x80", \ + "call __kernel_vsyscall", \ + X86_FEATURE_SYSFAST32) +# define __sys_clobber "memory" +# define __sys_nr(x,y) __NR_ ## x ## y +# define __sys_reg1 "ebx" +# define __sys_reg2 "ecx" +# define __sys_reg3 "edx" +# define __sys_reg4 "esi" +# define __sys_reg5 "edi" +#endif + +/* + * Example usage: + * + * result = VDSO_SYSCALL3(foo,64,x,y,z); + * + * ... calls foo(x,y,z) on 64 bits, and foo64(x,y,z) on 32 bits. + * + * VDSO_SYSCALL6() is currently missing, because it would require + * special handling for %ebp on 32 bits when the vdso is compiled with + * frame pointers enabled (the default on 32 bits.) Add it as a special + * case when and if it becomes necessary. + */ +#define _VDSO_SYSCALL(name,suf32,...) \ + ({ \ + long _sys_num_ret = __sys_nr(name,suf32); \ + asm_inline volatile( \ + __sys_instr \ + : "+a" (_sys_num_ret) \ + : __VA_ARGS__ \ + : __sys_clobber); \ + _sys_num_ret; \ + }) + +#define VDSO_SYSCALL0(name,suf32) \ + _VDSO_SYSCALL(name,suf32) +#define VDSO_SYSCALL1(name,suf32,a1) \ + ({ \ + register long _sys_arg1 asm(__sys_reg1) = (long)(a1); \ + _VDSO_SYSCALL(name,suf32, \ + "r" (_sys_arg1)); \ + }) +#define VDSO_SYSCALL2(name,suf32,a1,a2) \ + ({ \ + register long _sys_arg1 asm(__sys_reg1) = (long)(a1); \ + register long _sys_arg2 asm(__sys_reg2) = (long)(a2); \ + _VDSO_SYSCALL(name,suf32, \ + "r" (_sys_arg1), "r" (_sys_arg2)); \ + }) +#define VDSO_SYSCALL3(name,suf32,a1,a2,a3) \ + ({ \ + register long _sys_arg1 asm(__sys_reg1) = (long)(a1); \ + register long _sys_arg2 asm(__sys_reg2) = (long)(a2); \ + register long _sys_arg3 asm(__sys_reg3) = (long)(a3); \ + _VDSO_SYSCALL(name,suf32, \ + "r" (_sys_arg1), "r" (_sys_arg2), \ + "r" (_sys_arg3)); \ + }) +#define VDSO_SYSCALL4(name,suf32,a1,a2,a3,a4) \ + ({ \ + register long _sys_arg1 asm(__sys_reg1) = (long)(a1); \ + register long _sys_arg2 asm(__sys_reg2) = (long)(a2); \ + register long _sys_arg3 asm(__sys_reg3) = (long)(a3); \ + register long _sys_arg4 asm(__sys_reg4) = (long)(a4); \ + _VDSO_SYSCALL(name,suf32, \ + "r" (_sys_arg1), "r" (_sys_arg2), \ + "r" (_sys_arg3), "r" (_sys_arg4)); \ + }) +#define VDSO_SYSCALL5(name,suf32,a1,a2,a3,a4,a5) \ + ({ \ + register long _sys_arg1 asm(__sys_reg1) = (long)(a1); \ + register long _sys_arg2 asm(__sys_reg2) = (long)(a2); \ + register long _sys_arg3 asm(__sys_reg3) = (long)(a3); \ + register long _sys_arg4 asm(__sys_reg4) = (long)(a4); \ + register long _sys_arg5 asm(__sys_reg5) = (long)(a5); \ + _VDSO_SYSCALL(name,suf32, \ + "r" (_sys_arg1), "r" (_sys_arg2), \ + "r" (_sys_arg3), "r" (_sys_arg4), \ + "r" (_sys_arg5)); \ + }) + +#endif /* X86_VDSO_SYS_CALL_H */ |