mirror of
https://sourceware.org/git/glibc.git
synced 2024-12-05 19:21:05 +00:00
443 lines
13 KiB
C
443 lines
13 KiB
C
/* Copyright (C) 1992-2017 Free Software Foundation, Inc.
|
|
This file is part of the GNU C Library.
|
|
Contributed by Ulrich Drepper, <drepper@gnu.ai.mit.edu>, August 1995.
|
|
ARM changes by Philip Blundell, <pjb27@cam.ac.uk>, May 1997.
|
|
|
|
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_ARM_SYSDEP_H
|
|
#define _LINUX_ARM_SYSDEP_H 1
|
|
|
|
/* There is some commonality. */
|
|
#include <sysdeps/unix/sysv/linux/sysdep.h>
|
|
#include <sysdeps/unix/arm/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)
|
|
|
|
#include <bits/hwcap.h>
|
|
|
|
#ifdef __ASSEMBLER__
|
|
|
|
#ifndef ARCH_HAS_HARD_TP
|
|
/* Internal macro calling the linux kernel kuser_get_tls helper.
|
|
Note that in thumb mode, a constant pool break is often out of range, so
|
|
we always expand the constant inline. */
|
|
# ifdef __thumb2__
|
|
# define GET_TLS_BODY \
|
|
movw r0, #0x0fe0; \
|
|
movt r0, #0xffff; \
|
|
blx r0
|
|
# else
|
|
# define GET_TLS_BODY \
|
|
mov r0, #0xffff0fff; /* Point to the high page. */ \
|
|
mov lr, pc; /* Save our return address. */ \
|
|
sub pc, r0, #31 /* Jump to the TLS entry. */
|
|
# endif
|
|
|
|
/* Helper to get the TLS base pointer. Save LR in TMP, return in R0,
|
|
and no other registers clobbered. TMP may be LR itself to indicate
|
|
that no save is necessary. */
|
|
# undef GET_TLS
|
|
# define GET_TLS(TMP) \
|
|
.ifnc TMP, lr; \
|
|
mov TMP, lr; \
|
|
cfi_register (lr, TMP); \
|
|
GET_TLS_BODY; \
|
|
mov lr, TMP; \
|
|
cfi_restore (lr); \
|
|
.else; \
|
|
GET_TLS_BODY; \
|
|
.endif
|
|
#endif /* ARCH_HAS_HARD_TP */
|
|
|
|
/* 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 r0, $4096;
|
|
|
|
#define PSEUDO_RET \
|
|
it cc; \
|
|
RETINSTR(cc, lr); \
|
|
b PLTJMP(SYSCALL_ERROR)
|
|
#undef ret
|
|
#define ret PSEUDO_RET
|
|
|
|
#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);
|
|
|
|
#define PSEUDO_RET_NOERRNO \
|
|
DO_RET (lr);
|
|
|
|
#undef ret_NOERRNO
|
|
#define ret_NOERRNO PSEUDO_RET_NOERRNO
|
|
|
|
#undef PSEUDO_END_NOERRNO
|
|
#define PSEUDO_END_NOERRNO(name) \
|
|
END (name)
|
|
|
|
/* 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); \
|
|
rsb r0, r0, #0
|
|
|
|
#undef PSEUDO_END_ERRVAL
|
|
#define PSEUDO_END_ERRVAL(name) \
|
|
END (name)
|
|
|
|
#define ret_ERRVAL PSEUDO_RET_NOERRNO
|
|
|
|
#if !IS_IN (libc)
|
|
# define SYSCALL_ERROR __local_syscall_error
|
|
# if RTLD_PRIVATE_ERRNO
|
|
# define SYSCALL_ERROR_HANDLER \
|
|
__local_syscall_error: \
|
|
rsb r0, r0, #0; \
|
|
LDST_PCREL(str, r0, r1, C_SYMBOL_NAME(rtld_errno)); \
|
|
mvn r0, #0; \
|
|
DO_RET(lr)
|
|
# else
|
|
# if defined(__ARM_ARCH_4T__) && defined(__THUMB_INTERWORK__)
|
|
# define POP_PC \
|
|
pop { lr }; \
|
|
cfi_adjust_cfa_offset (-4); \
|
|
cfi_restore (lr); \
|
|
bx lr
|
|
# else
|
|
# define POP_PC pop { pc }
|
|
# endif
|
|
# define SYSCALL_ERROR_HANDLER \
|
|
__local_syscall_error: \
|
|
push { lr }; \
|
|
cfi_adjust_cfa_offset (4); \
|
|
cfi_rel_offset (lr, 0); \
|
|
push { r0 }; \
|
|
cfi_adjust_cfa_offset (4); \
|
|
bl PLTJMP(C_SYMBOL_NAME(__errno_location)); \
|
|
pop { r1 }; \
|
|
cfi_adjust_cfa_offset (-4); \
|
|
rsb r1, r1, #0; \
|
|
str r1, [r0]; \
|
|
mvn r0, #0; \
|
|
POP_PC;
|
|
# endif
|
|
#else
|
|
# define SYSCALL_ERROR_HANDLER /* Nothing here; code in sysdep.S is used. */
|
|
# define SYSCALL_ERROR __syscall_error
|
|
#endif
|
|
|
|
/* The ARM EABI user interface passes the syscall number in r7, instead
|
|
of in the swi. This is more efficient, because the kernel does not need
|
|
to fetch the swi from memory to find out the number; which can be painful
|
|
with separate I-cache and D-cache. Make sure to use 0 for the SWI
|
|
argument; otherwise the (optional) compatibility code for APCS binaries
|
|
may be invoked. */
|
|
|
|
/* Linux takes system call args in registers:
|
|
arg 1 r0
|
|
arg 2 r1
|
|
arg 3 r2
|
|
arg 4 r3
|
|
arg 5 r4 (this is different from the APCS convention)
|
|
arg 6 r5
|
|
arg 7 r6
|
|
|
|
The compiler is going to form a call by coming here, through PSEUDO, with
|
|
arguments
|
|
syscall number in the DO_CALL macro
|
|
arg 1 r0
|
|
arg 2 r1
|
|
arg 3 r2
|
|
arg 4 r3
|
|
arg 5 [sp]
|
|
arg 6 [sp+4]
|
|
arg 7 [sp+8]
|
|
|
|
We need to shuffle values between R4..R6 and the stack so that the
|
|
caller's v1..v3 and stack frame are not corrupted, and the kernel
|
|
sees the right arguments.
|
|
|
|
*/
|
|
|
|
/* We must save and restore r7 (call-saved) for the syscall number.
|
|
We never make function calls from inside here (only potentially
|
|
signal handlers), so we do not bother with doubleword alignment.
|
|
|
|
Just like the APCS syscall convention, the EABI syscall convention uses
|
|
r0 through r6 for up to seven syscall arguments. None are ever passed to
|
|
the kernel on the stack, although incoming arguments are on the stack for
|
|
syscalls with five or more arguments.
|
|
|
|
The assembler will convert the literal pool load to a move for most
|
|
syscalls. */
|
|
|
|
#undef DO_CALL
|
|
#define DO_CALL(syscall_name, args) \
|
|
DOARGS_##args; \
|
|
ldr r7, =SYS_ify (syscall_name); \
|
|
swi 0x0; \
|
|
UNDOARGS_##args
|
|
|
|
#undef DOARGS_0
|
|
#define DOARGS_0 \
|
|
.fnstart; \
|
|
push { r7 }; \
|
|
cfi_adjust_cfa_offset (4); \
|
|
cfi_rel_offset (r7, 0); \
|
|
.save { r7 }
|
|
#undef DOARGS_1
|
|
#define DOARGS_1 DOARGS_0
|
|
#undef DOARGS_2
|
|
#define DOARGS_2 DOARGS_0
|
|
#undef DOARGS_3
|
|
#define DOARGS_3 DOARGS_0
|
|
#undef DOARGS_4
|
|
#define DOARGS_4 DOARGS_0
|
|
#undef DOARGS_5
|
|
#define DOARGS_5 \
|
|
.fnstart; \
|
|
push {r4, r7}; \
|
|
cfi_adjust_cfa_offset (8); \
|
|
cfi_rel_offset (r4, 0); \
|
|
cfi_rel_offset (r7, 4); \
|
|
.save { r4, r7 }; \
|
|
ldr r4, [sp, #8]
|
|
#undef DOARGS_6
|
|
#define DOARGS_6 \
|
|
.fnstart; \
|
|
mov ip, sp; \
|
|
push {r4, r5, r7}; \
|
|
cfi_adjust_cfa_offset (12); \
|
|
cfi_rel_offset (r4, 0); \
|
|
cfi_rel_offset (r5, 4); \
|
|
cfi_rel_offset (r7, 8); \
|
|
.save { r4, r5, r7 }; \
|
|
ldmia ip, {r4, r5}
|
|
#undef DOARGS_7
|
|
#define DOARGS_7 \
|
|
.fnstart; \
|
|
mov ip, sp; \
|
|
push {r4, r5, r6, r7}; \
|
|
cfi_adjust_cfa_offset (16); \
|
|
cfi_rel_offset (r4, 0); \
|
|
cfi_rel_offset (r5, 4); \
|
|
cfi_rel_offset (r6, 8); \
|
|
cfi_rel_offset (r7, 12); \
|
|
.save { r4, r5, r6, r7 }; \
|
|
ldmia ip, {r4, r5, r6}
|
|
|
|
#undef UNDOARGS_0
|
|
#define UNDOARGS_0 \
|
|
pop {r7}; \
|
|
cfi_adjust_cfa_offset (-4); \
|
|
cfi_restore (r7); \
|
|
.fnend
|
|
#undef UNDOARGS_1
|
|
#define UNDOARGS_1 UNDOARGS_0
|
|
#undef UNDOARGS_2
|
|
#define UNDOARGS_2 UNDOARGS_0
|
|
#undef UNDOARGS_3
|
|
#define UNDOARGS_3 UNDOARGS_0
|
|
#undef UNDOARGS_4
|
|
#define UNDOARGS_4 UNDOARGS_0
|
|
#undef UNDOARGS_5
|
|
#define UNDOARGS_5 \
|
|
pop {r4, r7}; \
|
|
cfi_adjust_cfa_offset (-8); \
|
|
cfi_restore (r4); \
|
|
cfi_restore (r7); \
|
|
.fnend
|
|
#undef UNDOARGS_6
|
|
#define UNDOARGS_6 \
|
|
pop {r4, r5, r7}; \
|
|
cfi_adjust_cfa_offset (-12); \
|
|
cfi_restore (r4); \
|
|
cfi_restore (r5); \
|
|
cfi_restore (r7); \
|
|
.fnend
|
|
#undef UNDOARGS_7
|
|
#define UNDOARGS_7 \
|
|
pop {r4, r5, r6, r7}; \
|
|
cfi_adjust_cfa_offset (-16); \
|
|
cfi_restore (r4); \
|
|
cfi_restore (r5); \
|
|
cfi_restore (r6); \
|
|
cfi_restore (r7); \
|
|
.fnend
|
|
|
|
#else /* not __ASSEMBLER__ */
|
|
|
|
/* Define a macro which expands into the inline wrapper code for a system
|
|
call. */
|
|
#undef INLINE_SYSCALL
|
|
#define INLINE_SYSCALL(name, nr, args...) \
|
|
({ unsigned int _sys_result = INTERNAL_SYSCALL (name, , nr, args); \
|
|
if (__builtin_expect (INTERNAL_SYSCALL_ERROR_P (_sys_result, ), 0)) \
|
|
{ \
|
|
__set_errno (INTERNAL_SYSCALL_ERRNO (_sys_result, )); \
|
|
_sys_result = (unsigned int) -1; \
|
|
} \
|
|
(int) _sys_result; })
|
|
|
|
#undef INTERNAL_SYSCALL_DECL
|
|
#define INTERNAL_SYSCALL_DECL(err) do { } while (0)
|
|
|
|
#if defined(__thumb__)
|
|
/* We can not expose the use of r7 to the compiler. GCC (as
|
|
of 4.5) uses r7 as the hard frame pointer for Thumb - although
|
|
for Thumb-2 it isn't obviously a better choice than r11.
|
|
And GCC does not support asms that conflict with the frame
|
|
pointer.
|
|
|
|
This would be easier if syscall numbers never exceeded 255,
|
|
but they do. For the moment the LOAD_ARGS_7 is sacrificed.
|
|
We can't use push/pop inside the asm because that breaks
|
|
unwinding (i.e. thread cancellation) for this frame. We can't
|
|
locally save and restore r7, because we do not know if this
|
|
function uses r7 or if it is our caller's r7; if it is our caller's,
|
|
then unwinding will fail higher up the stack. So we move the
|
|
syscall out of line and provide its own unwind information. */
|
|
# undef INTERNAL_SYSCALL_RAW
|
|
# define INTERNAL_SYSCALL_RAW(name, err, nr, args...) \
|
|
({ \
|
|
register int _a1 asm ("a1"); \
|
|
int _nametmp = name; \
|
|
LOAD_ARGS_##nr (args) \
|
|
register int _name asm ("ip") = _nametmp; \
|
|
asm volatile ("bl __libc_do_syscall" \
|
|
: "=r" (_a1) \
|
|
: "r" (_name) ASM_ARGS_##nr \
|
|
: "memory", "lr"); \
|
|
_a1; })
|
|
#else /* ARM */
|
|
# undef INTERNAL_SYSCALL_RAW
|
|
# define INTERNAL_SYSCALL_RAW(name, err, nr, args...) \
|
|
({ \
|
|
register int _a1 asm ("r0"), _nr asm ("r7"); \
|
|
LOAD_ARGS_##nr (args) \
|
|
_nr = name; \
|
|
asm volatile ("swi 0x0 @ syscall " #name \
|
|
: "=r" (_a1) \
|
|
: "r" (_nr) ASM_ARGS_##nr \
|
|
: "memory"); \
|
|
_a1; })
|
|
#endif
|
|
|
|
#undef INTERNAL_SYSCALL
|
|
#define INTERNAL_SYSCALL(name, err, nr, args...) \
|
|
INTERNAL_SYSCALL_RAW(SYS_ify(name), err, nr, args)
|
|
|
|
#undef INTERNAL_SYSCALL_ARM
|
|
#define INTERNAL_SYSCALL_ARM(name, err, nr, args...) \
|
|
INTERNAL_SYSCALL_RAW(__ARM_NR_##name, err, nr, args)
|
|
|
|
#undef INTERNAL_SYSCALL_ERROR_P
|
|
#define INTERNAL_SYSCALL_ERROR_P(val, err) \
|
|
((unsigned int) (val) >= 0xfffff001u)
|
|
|
|
#undef INTERNAL_SYSCALL_ERRNO
|
|
#define INTERNAL_SYSCALL_ERRNO(val, err) (-(val))
|
|
|
|
/* List of system calls which are supported as vsyscalls. */
|
|
#define HAVE_CLOCK_GETTIME_VSYSCALL 1
|
|
#define HAVE_GETTIMEOFDAY_VSYSCALL 1
|
|
|
|
#define LOAD_ARGS_0()
|
|
#define ASM_ARGS_0
|
|
#define LOAD_ARGS_1(a1) \
|
|
int _a1tmp = (int) (a1); \
|
|
LOAD_ARGS_0 () \
|
|
_a1 = _a1tmp;
|
|
#define ASM_ARGS_1 ASM_ARGS_0, "r" (_a1)
|
|
#define LOAD_ARGS_2(a1, a2) \
|
|
int _a2tmp = (int) (a2); \
|
|
LOAD_ARGS_1 (a1) \
|
|
register int _a2 asm ("a2") = _a2tmp;
|
|
#define ASM_ARGS_2 ASM_ARGS_1, "r" (_a2)
|
|
#define LOAD_ARGS_3(a1, a2, a3) \
|
|
int _a3tmp = (int) (a3); \
|
|
LOAD_ARGS_2 (a1, a2) \
|
|
register int _a3 asm ("a3") = _a3tmp;
|
|
#define ASM_ARGS_3 ASM_ARGS_2, "r" (_a3)
|
|
#define LOAD_ARGS_4(a1, a2, a3, a4) \
|
|
int _a4tmp = (int) (a4); \
|
|
LOAD_ARGS_3 (a1, a2, a3) \
|
|
register int _a4 asm ("a4") = _a4tmp;
|
|
#define ASM_ARGS_4 ASM_ARGS_3, "r" (_a4)
|
|
#define LOAD_ARGS_5(a1, a2, a3, a4, a5) \
|
|
int _v1tmp = (int) (a5); \
|
|
LOAD_ARGS_4 (a1, a2, a3, a4) \
|
|
register int _v1 asm ("v1") = _v1tmp;
|
|
#define ASM_ARGS_5 ASM_ARGS_4, "r" (_v1)
|
|
#define LOAD_ARGS_6(a1, a2, a3, a4, a5, a6) \
|
|
int _v2tmp = (int) (a6); \
|
|
LOAD_ARGS_5 (a1, a2, a3, a4, a5) \
|
|
register int _v2 asm ("v2") = _v2tmp;
|
|
#define ASM_ARGS_6 ASM_ARGS_5, "r" (_v2)
|
|
#ifndef __thumb__
|
|
# define LOAD_ARGS_7(a1, a2, a3, a4, a5, a6, a7) \
|
|
int _v3tmp = (int) (a7); \
|
|
LOAD_ARGS_6 (a1, a2, a3, a4, a5, a6) \
|
|
register int _v3 asm ("v3") = _v3tmp;
|
|
# define ASM_ARGS_7 ASM_ARGS_6, "r" (_v3)
|
|
#endif
|
|
|
|
/* For EABI, non-constant syscalls are actually pretty easy... */
|
|
#undef INTERNAL_SYSCALL_NCS
|
|
#define INTERNAL_SYSCALL_NCS(number, err, nr, args...) \
|
|
INTERNAL_SYSCALL_RAW (number, err, nr, args)
|
|
|
|
#endif /* __ASSEMBLER__ */
|
|
|
|
#endif /* linux/arm/sysdep.h */
|