| /* Copyright (C) 1996-2018 Free Software Foundation, Inc. |
| This file is part of the GNU C Library. |
| Written by Andreas Schwab, <schwab@issan.informatik.uni-dortmund.de>, |
| December 1995. |
| |
| 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/>. */ |
| |
| #include <sysdeps/unix/sysv/linux/sysdep.h> |
| #include <tls.h> |
| |
| /* Defines RTLD_PRIVATE_ERRNO. */ |
| #include <dl-sysdep.h> |
| |
| /* 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 %d0 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 savely test with -4095. */ |
| |
| /* We don't want the label for the error handler to be visible in the symbol |
| table when we define it here. */ |
| #ifdef PIC |
| #define SYSCALL_ERROR_LABEL .Lsyscall_error |
| #else |
| #define SYSCALL_ERROR_LABEL __syscall_error |
| #endif |
| |
| #undef PSEUDO |
| #define PSEUDO(name, syscall_name, args) \ |
| .text; \ |
| ENTRY (name) \ |
| DO_CALL (syscall_name, args); \ |
| cmp.l &-4095, %d0; \ |
| jcc SYSCALL_ERROR_LABEL |
| |
| #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 rts |
| |
| /* 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); \ |
| negl %d0 |
| |
| #undef PSEUDO_END_ERRVAL |
| #define PSEUDO_END_ERRVAL(name) \ |
| END (name) |
| |
| #define ret_ERRVAL rts |
| |
| #ifdef PIC |
| # if RTLD_PRIVATE_ERRNO |
| # define SYSCALL_ERROR_HANDLER \ |
| SYSCALL_ERROR_LABEL: \ |
| PCREL_OP (lea, rtld_errno, %a0, %a0); \ |
| neg.l %d0; \ |
| move.l %d0, (%a0); \ |
| move.l &-1, %d0; \ |
| /* Copy return value to %a0 for syscalls that are declared to return \ |
| a pointer (e.g., mmap). */ \ |
| move.l %d0, %a0; \ |
| rts; |
| # elif defined _LIBC_REENTRANT |
| # if IS_IN (libc) |
| # define SYSCALL_ERROR_ERRNO __libc_errno |
| # else |
| # define SYSCALL_ERROR_ERRNO errno |
| # endif |
| # define SYSCALL_ERROR_HANDLER \ |
| SYSCALL_ERROR_LABEL: \ |
| neg.l %d0; \ |
| move.l %d0, -(%sp); \ |
| cfi_adjust_cfa_offset (4); \ |
| jbsr __m68k_read_tp@PLTPC; \ |
| SYSCALL_ERROR_LOAD_GOT (%a1); \ |
| add.l (SYSCALL_ERROR_ERRNO@TLSIE, %a1), %a0; \ |
| move.l (%sp)+, (%a0); \ |
| cfi_adjust_cfa_offset (-4); \ |
| move.l &-1, %d0; \ |
| /* Copy return value to %a0 for syscalls that are declared to return \ |
| a pointer (e.g., mmap). */ \ |
| move.l %d0, %a0; \ |
| rts; |
| # else /* !_LIBC_REENTRANT */ |
| /* Store (- %d0) into errno through the GOT. */ |
| # define SYSCALL_ERROR_HANDLER \ |
| SYSCALL_ERROR_LABEL: \ |
| move.l (errno@GOTPC, %pc), %a0; \ |
| neg.l %d0; \ |
| move.l %d0, (%a0); \ |
| move.l &-1, %d0; \ |
| /* Copy return value to %a0 for syscalls that are declared to return \ |
| a pointer (e.g., mmap). */ \ |
| move.l %d0, %a0; \ |
| rts; |
| # endif /* _LIBC_REENTRANT */ |
| #else |
| # define SYSCALL_ERROR_HANDLER /* Nothing here; code in sysdep.S is used. */ |
| #endif /* PIC */ |
| |
| /* Linux takes system call arguments in registers: |
| |
| syscall number %d0 call-clobbered |
| arg 1 %d1 call-clobbered |
| arg 2 %d2 call-saved |
| arg 3 %d3 call-saved |
| arg 4 %d4 call-saved |
| arg 5 %d5 call-saved |
| arg 6 %a0 call-clobbered |
| |
| The stack layout upon entering the function is: |
| |
| 24(%sp) Arg# 6 |
| 20(%sp) Arg# 5 |
| 16(%sp) Arg# 4 |
| 12(%sp) Arg# 3 |
| 8(%sp) Arg# 2 |
| 4(%sp) Arg# 1 |
| (%sp) Return address |
| |
| (Of course a function with say 3 arguments does not have entries for |
| arguments 4 and 5.) |
| |
| Separate move's are faster than movem, but need more space. Since |
| speed is more important, we don't use movem. Since %a0 and %a1 are |
| scratch registers, we can use them for saving as well. */ |
| |
| #define DO_CALL(syscall_name, args) \ |
| move.l &SYS_ify(syscall_name), %d0; \ |
| DOARGS_##args \ |
| trap &0; \ |
| UNDOARGS_##args |
| |
| #define DOARGS_0 /* No arguments to frob. */ |
| #define UNDOARGS_0 /* No arguments to unfrob. */ |
| #define _DOARGS_0(n) /* No arguments to frob. */ |
| |
| #define DOARGS_1 _DOARGS_1 (4) |
| #define _DOARGS_1(n) move.l n(%sp), %d1; _DOARGS_0 (n) |
| #define UNDOARGS_1 UNDOARGS_0 |
| |
| #define DOARGS_2 _DOARGS_2 (8) |
| #define _DOARGS_2(n) move.l %d2, %a0; cfi_register (%d2, %a0); \ |
| move.l n(%sp), %d2; _DOARGS_1 (n-4) |
| #define UNDOARGS_2 UNDOARGS_1; move.l %a0, %d2; cfi_restore (%d2) |
| |
| #define DOARGS_3 _DOARGS_3 (12) |
| #define _DOARGS_3(n) move.l %d3, %a1; cfi_register (%d3, %a1); \ |
| move.l n(%sp), %d3; _DOARGS_2 (n-4) |
| #define UNDOARGS_3 UNDOARGS_2; move.l %a1, %d3; cfi_restore (%d3) |
| |
| #define DOARGS_4 _DOARGS_4 (16) |
| #define _DOARGS_4(n) move.l %d4, -(%sp); \ |
| cfi_adjust_cfa_offset (4); cfi_rel_offset (%d4, 0); \ |
| move.l n+4(%sp), %d4; _DOARGS_3 (n) |
| #define UNDOARGS_4 UNDOARGS_3; move.l (%sp)+, %d4; \ |
| cfi_adjust_cfa_offset (-4); cfi_restore (%d4) |
| |
| #define DOARGS_5 _DOARGS_5 (20) |
| #define _DOARGS_5(n) move.l %d5, -(%sp); \ |
| cfi_adjust_cfa_offset (4); cfi_rel_offset (%d5, 0); \ |
| move.l n+4(%sp), %d5; _DOARGS_4 (n) |
| #define UNDOARGS_5 UNDOARGS_4; move.l (%sp)+, %d5; \ |
| cfi_adjust_cfa_offset (-4); cfi_restore (%d5) |
| |
| #define DOARGS_6 _DOARGS_6 (24) |
| #define _DOARGS_6(n) _DOARGS_5 (n-4); move.l %a0, -(%sp); \ |
| cfi_adjust_cfa_offset (4); \ |
| move.l n+12(%sp), %a0; |
| #define UNDOARGS_6 move.l (%sp)+, %a0; cfi_adjust_cfa_offset (-4); \ |
| UNDOARGS_5 |
| |
| |
| #define ret rts |
| #if 0 /* Not used by Linux */ |
| #define r0 %d0 |
| #define r1 %d1 |
| #define MOVE(x,y) movel x , y |
| #endif |
| |
| #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) |
| |
| /* Define a macro which expands inline into the wrapper code for a system |
| call. This use is for internal calls that do not need to handle errors |
| normally. It will never touch errno. This returns just what the kernel |
| gave back. */ |
| #undef INTERNAL_SYSCALL |
| #define INTERNAL_SYSCALL_NCS(name, err, nr, args...) \ |
| ({ unsigned int _sys_result; \ |
| { \ |
| /* Load argument values in temporary variables |
| to perform side effects like function calls |
| before the call used registers are set. */ \ |
| LOAD_ARGS_##nr (args) \ |
| LOAD_REGS_##nr \ |
| register int _d0 asm ("%d0") = name; \ |
| asm volatile ("trap #0" \ |
| : "=d" (_d0) \ |
| : "0" (_d0) ASM_ARGS_##nr \ |
| : "memory"); \ |
| _sys_result = _d0; \ |
| } \ |
| (int) _sys_result; }) |
| #define INTERNAL_SYSCALL(name, err, nr, args...) \ |
| INTERNAL_SYSCALL_NCS (__NR_##name, err, nr, ##args) |
| |
| #undef INTERNAL_SYSCALL_ERROR_P |
| #define INTERNAL_SYSCALL_ERROR_P(val, err) \ |
| ((unsigned int) (val) >= -4095U) |
| |
| #undef INTERNAL_SYSCALL_ERRNO |
| #define INTERNAL_SYSCALL_ERRNO(val, err) (-(val)) |
| |
| #define LOAD_ARGS_0() |
| #define LOAD_REGS_0 |
| #define ASM_ARGS_0 |
| #define LOAD_ARGS_1(a1) \ |
| LOAD_ARGS_0 () \ |
| int __arg1 = (int) (a1); |
| #define LOAD_REGS_1 \ |
| register int _d1 asm ("d1") = __arg1; \ |
| LOAD_REGS_0 |
| #define ASM_ARGS_1 ASM_ARGS_0, "d" (_d1) |
| #define LOAD_ARGS_2(a1, a2) \ |
| LOAD_ARGS_1 (a1) \ |
| int __arg2 = (int) (a2); |
| #define LOAD_REGS_2 \ |
| register int _d2 asm ("d2") = __arg2; \ |
| LOAD_REGS_1 |
| #define ASM_ARGS_2 ASM_ARGS_1, "d" (_d2) |
| #define LOAD_ARGS_3(a1, a2, a3) \ |
| LOAD_ARGS_2 (a1, a2) \ |
| int __arg3 = (int) (a3); |
| #define LOAD_REGS_3 \ |
| register int _d3 asm ("d3") = __arg3; \ |
| LOAD_REGS_2 |
| #define ASM_ARGS_3 ASM_ARGS_2, "d" (_d3) |
| #define LOAD_ARGS_4(a1, a2, a3, a4) \ |
| LOAD_ARGS_3 (a1, a2, a3) \ |
| int __arg4 = (int) (a4); |
| #define LOAD_REGS_4 \ |
| register int _d4 asm ("d4") = __arg4; \ |
| LOAD_REGS_3 |
| #define ASM_ARGS_4 ASM_ARGS_3, "d" (_d4) |
| #define LOAD_ARGS_5(a1, a2, a3, a4, a5) \ |
| LOAD_ARGS_4 (a1, a2, a3, a4) \ |
| int __arg5 = (int) (a5); |
| #define LOAD_REGS_5 \ |
| register int _d5 asm ("d5") = __arg5; \ |
| LOAD_REGS_4 |
| #define ASM_ARGS_5 ASM_ARGS_4, "d" (_d5) |
| #define LOAD_ARGS_6(a1, a2, a3, a4, a5, a6) \ |
| LOAD_ARGS_5 (a1, a2, a3, a4, a5) \ |
| int __arg6 = (int) (a6); |
| #define LOAD_REGS_6 \ |
| register int _a0 asm ("a0") = __arg6; \ |
| LOAD_REGS_5 |
| #define ASM_ARGS_6 ASM_ARGS_5, "a" (_a0) |
| |
| #endif /* not __ASSEMBLER__ */ |
| |
| /* Pointer mangling is not yet supported for M68K. */ |
| #define PTR_MANGLE(var) (void) (var) |
| #define PTR_DEMANGLE(var) (void) (var) |
| |
| #if defined NEED_DL_SYSINFO || defined NEED_DL_SYSINFO_DSO |
| /* M68K needs system-supplied DSO to access TLS helpers |
| even when statically linked. */ |
| # define NEED_STATIC_SYSINFO_DSO 1 |
| #endif |
