glibc/sysdeps/unix/sysv/linux/aarch64/sysdep.h
Florian Weimer 88f4b6929c Introduce <pointer_guard.h>, extracted from <sysdep.h>
This allows us to define a generic no-op version of PTR_MANGLE and
PTR_DEMANGLE.  In the future, we can use PTR_MANGLE and PTR_DEMANGLE
unconditionally in C sources, avoiding an unintended loss of hardening
due to missing include files or unlucky header inclusion ordering.

In i386 and x86_64, we can avoid a <tls.h> dependency in the C
code by using the computed constant from <tcb-offsets.h>.  <sysdep.h>
no longer includes these definitions, so there is no cyclic dependency
anymore when computing the <tcb-offsets.h> constants.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2022-10-18 17:03:55 +02:00

237 lines
6.8 KiB
C

/* Copyright (C) 2005-2022 Free Software Foundation, Inc.
This file is part of the GNU C Library.
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
<https://www.gnu.org/licenses/>. */
#ifndef _LINUX_AARCH64_SYSDEP_H
#define _LINUX_AARCH64_SYSDEP_H 1
#include <sysdeps/unix/sysdep.h>
#include <sysdeps/aarch64/sysdep.h>
#include <sysdeps/unix/sysv/linux/generic/sysdep.h>
/* Defines RTLD_PRIVATE_ERRNO and USE_DL_SYSINFO. */
#include <dl-sysdep.h>
#include <tls.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__
/* 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 !IS_IN (libc)
# define SYSCALL_ERROR .Lsyscall_error
# if RTLD_PRIVATE_ERRNO
# define SYSCALL_ERROR_HANDLER \
.Lsyscall_error: \
adrp x1, C_SYMBOL_NAME(rtld_errno); \
neg w0, w0; \
str w0, [x1, :lo12:C_SYMBOL_NAME(rtld_errno)]; \
mov x0, -1; \
RET;
# else
# define SYSCALL_ERROR_HANDLER \
.Lsyscall_error: \
adrp x1, :gottprel:errno; \
neg w2, w0; \
ldr PTR_REG(1), [x1, :gottprel_lo12:errno]; \
mrs x3, tpidr_el0; \
mov x0, -1; \
str w2, [x1, x3]; \
RET;
# endif
# else
# define SYSCALL_ERROR __syscall_error
# define SYSCALL_ERROR_HANDLER \
.Lsyscall_error: \
b __syscall_error;
# endif
/* Linux takes system call args in registers:
syscall number x8
arg 1 x0
arg 2 x1
arg 3 x2
arg 4 x3
arg 5 x4
arg 6 x5
arg 7 x6
The compiler is going to form a call by coming here, through PSEUDO, with
arguments
syscall number in the DO_CALL macro
arg 1 x0
arg 2 x1
arg 3 x2
arg 4 x3
arg 5 x4
arg 6 x5
arg 7 x6
*/
# undef DO_CALL
# define DO_CALL(syscall_name, args) \
mov x8, SYS_ify (syscall_name); \
svc 0
#else /* not __ASSEMBLER__ */
# ifdef __LP64__
# define VDSO_NAME "LINUX_2.6.39"
# define VDSO_HASH 123718537
# else
# define VDSO_NAME "LINUX_4.9"
# define VDSO_HASH 61765625
# endif
/* List of system calls which are supported as vsyscalls. */
# define HAVE_CLOCK_GETRES64_VSYSCALL "__kernel_clock_getres"
# define HAVE_CLOCK_GETTIME64_VSYSCALL "__kernel_clock_gettime"
# define HAVE_GETTIMEOFDAY_VSYSCALL "__kernel_gettimeofday"
# undef INTERNAL_SYSCALL_RAW
# define INTERNAL_SYSCALL_RAW(name, nr, args...) \
({ long _sys_result; \
{ \
LOAD_ARGS_##nr (args) \
register long _x8 asm ("x8") = (name); \
asm volatile ("svc 0 // syscall " # name \
: "=r" (_x0) : "r"(_x8) ASM_ARGS_##nr : "memory"); \
_sys_result = _x0; \
} \
_sys_result; })
# undef INTERNAL_SYSCALL
# define INTERNAL_SYSCALL(name, nr, args...) \
INTERNAL_SYSCALL_RAW(SYS_ify(name), nr, args)
# undef INTERNAL_SYSCALL_AARCH64
# define INTERNAL_SYSCALL_AARCH64(name, nr, args...) \
INTERNAL_SYSCALL_RAW(__ARM_NR_##name, nr, args)
# define LOAD_ARGS_0() \
register long _x0 asm ("x0");
# define LOAD_ARGS_1(x0) \
long _x0tmp = (long) (x0); \
LOAD_ARGS_0 () \
_x0 = _x0tmp;
# define LOAD_ARGS_2(x0, x1) \
long _x1tmp = (long) (x1); \
LOAD_ARGS_1 (x0) \
register long _x1 asm ("x1") = _x1tmp;
# define LOAD_ARGS_3(x0, x1, x2) \
long _x2tmp = (long) (x2); \
LOAD_ARGS_2 (x0, x1) \
register long _x2 asm ("x2") = _x2tmp;
# define LOAD_ARGS_4(x0, x1, x2, x3) \
long _x3tmp = (long) (x3); \
LOAD_ARGS_3 (x0, x1, x2) \
register long _x3 asm ("x3") = _x3tmp;
# define LOAD_ARGS_5(x0, x1, x2, x3, x4) \
long _x4tmp = (long) (x4); \
LOAD_ARGS_4 (x0, x1, x2, x3) \
register long _x4 asm ("x4") = _x4tmp;
# define LOAD_ARGS_6(x0, x1, x2, x3, x4, x5) \
long _x5tmp = (long) (x5); \
LOAD_ARGS_5 (x0, x1, x2, x3, x4) \
register long _x5 asm ("x5") = _x5tmp;
# define LOAD_ARGS_7(x0, x1, x2, x3, x4, x5, x6)\
long _x6tmp = (long) (x6); \
LOAD_ARGS_6 (x0, x1, x2, x3, x4, x5) \
register long _x6 asm ("x6") = _x6tmp;
# define ASM_ARGS_0
# define ASM_ARGS_1 , "r" (_x0)
# define ASM_ARGS_2 ASM_ARGS_1, "r" (_x1)
# define ASM_ARGS_3 ASM_ARGS_2, "r" (_x2)
# define ASM_ARGS_4 ASM_ARGS_3, "r" (_x3)
# define ASM_ARGS_5 ASM_ARGS_4, "r" (_x4)
# define ASM_ARGS_6 ASM_ARGS_5, "r" (_x5)
# define ASM_ARGS_7 ASM_ARGS_6, "r" (_x6)
# undef INTERNAL_SYSCALL_NCS
# define INTERNAL_SYSCALL_NCS(number, nr, args...) \
INTERNAL_SYSCALL_RAW (number, nr, args)
#undef HAVE_INTERNAL_BRK_ADDR_SYMBOL
#define HAVE_INTERNAL_BRK_ADDR_SYMBOL 1
#endif /* __ASSEMBLER__ */
#endif /* linux/aarch64/sysdep.h */