diff options
Diffstat (limited to 'libc/sysdeps/linux/aarch64/sysdep.h')
| -rw-r--r-- | libc/sysdeps/linux/aarch64/sysdep.h | 150 |
1 files changed, 150 insertions, 0 deletions
diff --git a/libc/sysdeps/linux/aarch64/sysdep.h b/libc/sysdeps/linux/aarch64/sysdep.h new file mode 100644 index 000000000..82790be6d --- /dev/null +++ b/libc/sysdeps/linux/aarch64/sysdep.h @@ -0,0 +1,150 @@ +/* Copyright (C) 2005-2016 Free Software Foundation, Inc. + +The GNU C Library is free software; you can redistribute it and/or +modify it under the terms of the GNU Lesser General Public License as +published by the Free Software Foundation; either version 2.1 of the +License, or (at your option) any later version. + +The GNU C Library is distributed in the hope that it will be useful, +but WITHOUT ANY WARRANTY; without even the implied warranty of +MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU +Lesser General Public License for more details. + +You should have received a copy of the GNU Lesser General Public +License along with the GNU C Library; if not, see +<http://www.gnu.org/licenses/>. */ + +#ifndef _LINUX_AARCH64_SYSDEP_H +#define _LINUX_AARCH64_SYSDEP_H 1 + +#include <common/sysdep.h> +#include <sys/syscall.h> + +/* In order to get __set_errno() definition in INLINE_SYSCALL. */ +#ifndef __ASSEMBLER__ +#include <errno.h> +#endif + +/* For Linux we can use the system call table in the header file +/usr/include/asm/unistd.h +of the kernel. But these symbols do not follow the SYS_* syntax +so we have to redefine the `SYS_ify' macro here. */ +#undef SYS_ify +#define SYS_ify(syscall_name) (__NR_##syscall_name) + +#ifdef __ASSEMBLER__ + +#define ASM_SIZE_DIRECTIVE(name) .size name,.-name + +/* Local label name for asm code. */ +#ifndef L +# define L(name) .L##name +#endif + +/* Define an entry point visible from C. */ +#define ENTRY(name) \ + .globl C_SYMBOL_NAME(name); \ + .type C_SYMBOL_NAME(name),%function; \ + .align 4; \ + C_LABEL(name) \ + cfi_startproc; + +/* Define an entry point visible from C. */ +#define ENTRY_ALIGN(name, align) \ + .globl C_SYMBOL_NAME(name); \ + .type C_SYMBOL_NAME(name),%function; \ + .p2align align; \ + C_LABEL(name) \ + cfi_startproc; + +#undef END +#define END(name) \ + cfi_endproc; \ + ASM_SIZE_DIRECTIVE(name) + +/* Linux uses a negative return value to indicate syscall errors, +unlike most Unices, which use the condition codes' carry flag. + +Since version 2.1 the return value of a system call might be +negative even if the call succeeded. E.g., the `lseek' system call +might return a large offset. Therefore we must not anymore test +for < 0, but test for a real error by making sure the value in R0 +is a real error number. Linus said he will make sure the no syscall +returns a value in -1 .. -4095 as a valid result so we can safely +test with -4095. */ + +# undef PSEUDO +# define PSEUDO(name, syscall_name, args) \ +.text; \ +ENTRY (name); \ +DO_CALL (syscall_name, args); \ +cmn x0, #4095; \ +b.cs .Lsyscall_error; + +# undef PSEUDO_END +# define PSEUDO_END(name) \ +SYSCALL_ERROR_HANDLER \ +END (name) + +# undef PSEUDO_NOERRNO +# define PSEUDO_NOERRNO(name, syscall_name, args) \ +.text; \ +ENTRY (name); \ +DO_CALL (syscall_name, args); + +# undef PSEUDO_END_NOERRNO +# define PSEUDO_END_NOERRNO(name) \ +END (name) + +# define ret_NOERRNO ret + +/* The function has to return the error code. */ +# undef PSEUDO_ERRVAL +# define PSEUDO_ERRVAL(name, syscall_name, args) \ +.text; \ +ENTRY (name) \ +DO_CALL (syscall_name, args); \ +neg x0, x0 + +# undef PSEUDO_END_ERRVAL +# define PSEUDO_END_ERRVAL(name) \ +END (name) + +# define ret_ERRVAL ret + +#if defined _LIBC_REENTRANT +# if defined USE___THREAD +# ifndef NOT_IN_libc +# define SYSCALL_ERROR_ERRNO __libc_errno +# else +# define SYSCALL_ERROR_ERRNO errno +# endif +# endif +#endif + +#if defined USE___THREAD +# define SYSCALL_ERROR .Lsyscall_error +# define SYSCALL_ERROR_HANDLER \ +.Lsyscall_error: \ + adrp x1, :gottprel:SYSCALL_ERROR_ERRNO; \ + neg w2, w0; \ + ldr x1, [x1, :gottprel_lo12:SYSCALL_ERROR_ERRNO]; \ + mrs x3, tpidr_el0; \ + mov x0, -1; \ + str w2, [x1, x3]; \ + ret; +#else +# define SYSCALL_ERROR __syscall_error +# define SYSCALL_ERROR_HANDLER \ +.Lsyscall_error: \ + b __syscall_error; +#endif + +# undef DO_CALL +# define DO_CALL(syscall_name, args) \ +mov x8, SYS_ify (syscall_name); \ +svc 0 + +#endif /* __ASSEMBLER__ */ + +#endif /* linux/aarch64/sysdep.h */ |