| /* Copyright (C) 1992-2018 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) |
| |
| #define SINGLE_THREAD_BY_GLOBAL 1 |
| |
| #endif /* __ASSEMBLER__ */ |
| |
| #endif /* linux/arm/sysdep.h */ |