| /* Copyright (C) 2001-2014 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 |
| <http://www.gnu.org/licenses/>. */ |
| |
| #ifndef _LINUX_X86_64_SYSDEP_H |
| #define _LINUX_X86_64_SYSDEP_H 1 |
| |
| /* There is some commonality. */ |
| #include <sysdeps/unix/x86_64/sysdep.h> |
| #include <tls.h> |
| |
| #ifdef IS_IN_rtld |
| # include <dl-sysdep.h> /* Defines RTLD_PRIVATE_ERRNO. */ |
| #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 |
| |
| /* This is a kludge to make syscalls.list find these under the names |
| pread and pwrite, since some kernel headers define those names |
| and some define the *64 names for the same system calls. */ |
| #if !defined __NR_pread && defined __NR_pread64 |
| # define __NR_pread __NR_pread64 |
| #endif |
| #if !defined __NR_pwrite && defined __NR_pwrite64 |
| # define __NR_pwrite __NR_pwrite64 |
| #endif |
| |
| /* This is to help the old kernel headers where __NR_semtimedop is not |
| available. */ |
| #ifndef __NR_semtimedop |
| # define __NR_semtimedop 220 |
| #endif |
| |
| |
| #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 %eax |
| 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 handle to be global when we define |
| it here. */ |
| # ifdef PIC |
| # define SYSCALL_ERROR_LABEL 0f |
| # else |
| # define SYSCALL_ERROR_LABEL syscall_error |
| # endif |
| |
| # undef PSEUDO |
| # define PSEUDO(name, syscall_name, args) \ |
| .text; \ |
| ENTRY (name) \ |
| DO_CALL (syscall_name, args); \ |
| cmpq $-4095, %rax; \ |
| jae 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 ret |
| |
| # undef PSEUDO_ERRVAL |
| # define PSEUDO_ERRVAL(name, syscall_name, args) \ |
| .text; \ |
| ENTRY (name) \ |
| DO_CALL (syscall_name, args); \ |
| negq %rax |
| |
| # undef PSEUDO_END_ERRVAL |
| # define PSEUDO_END_ERRVAL(name) \ |
| END (name) |
| |
| # define ret_ERRVAL ret |
| |
| # if defined PIC && defined RTLD_PRIVATE_ERRNO |
| # define SYSCALL_SET_ERRNO \ |
| lea rtld_errno(%rip), %RCX_LP; \ |
| neg %eax; \ |
| movl %eax, (%rcx) |
| # else |
| # ifndef NOT_IN_libc |
| # define SYSCALL_ERROR_ERRNO __libc_errno |
| # else |
| # define SYSCALL_ERROR_ERRNO errno |
| # endif |
| # define SYSCALL_SET_ERRNO \ |
| movq SYSCALL_ERROR_ERRNO@GOTTPOFF(%rip), %rcx;\ |
| neg %eax; \ |
| movl %eax, %fs:(%rcx); |
| # endif |
| |
| # ifndef PIC |
| # define SYSCALL_ERROR_HANDLER /* Nothing here; code in sysdep.S is used. */ |
| # else |
| # define SYSCALL_ERROR_HANDLER \ |
| 0: \ |
| SYSCALL_SET_ERRNO; \ |
| or $-1, %RAX_LP; \ |
| ret; |
| # endif /* PIC */ |
| |
| /* The Linux/x86-64 kernel expects the system call parameters in |
| registers according to the following table: |
| |
| syscall number rax |
| arg 1 rdi |
| arg 2 rsi |
| arg 3 rdx |
| arg 4 r10 |
| arg 5 r8 |
| arg 6 r9 |
| |
| The Linux kernel uses and destroys internally these registers: |
| return address from |
| syscall rcx |
| eflags from syscall r11 |
| |
| Normal function call, including calls to the system call stub |
| functions in the libc, get the first six parameters passed in |
| registers and the seventh parameter and later on the stack. The |
| register use is as follows: |
| |
| system call number in the DO_CALL macro |
| arg 1 rdi |
| arg 2 rsi |
| arg 3 rdx |
| arg 4 rcx |
| arg 5 r8 |
| arg 6 r9 |
| |
| We have to take care that the stack is aligned to 16 bytes. When |
| called the stack is not aligned since the return address has just |
| been pushed. |
| |
| |
| Syscalls of more than 6 arguments are not supported. */ |
| |
| # undef DO_CALL |
| # define DO_CALL(syscall_name, args) \ |
| DOARGS_##args \ |
| movl $SYS_ify (syscall_name), %eax; \ |
| syscall; |
| |
| # define DOARGS_0 /* nothing */ |
| # define DOARGS_1 /* nothing */ |
| # define DOARGS_2 /* nothing */ |
| # define DOARGS_3 /* nothing */ |
| # define DOARGS_4 movq %rcx, %r10; |
| # define DOARGS_5 DOARGS_4 |
| # define DOARGS_6 DOARGS_5 |
| |
| #else /* !__ASSEMBLER__ */ |
| /* Define a macro which expands inline into the wrapper code for a system |
| call. */ |
| # undef INLINE_SYSCALL |
| # define INLINE_SYSCALL(name, nr, args...) \ |
| ({ \ |
| unsigned long int resultvar = INTERNAL_SYSCALL (name, , nr, args); \ |
| if (__builtin_expect (INTERNAL_SYSCALL_ERROR_P (resultvar, ), 0)) \ |
| { \ |
| __set_errno (INTERNAL_SYSCALL_ERRNO (resultvar, )); \ |
| resultvar = (unsigned long int) -1; \ |
| } \ |
| (long int) resultvar; }) |
| |
| /* Define a macro with explicit types for arguments, which expands inline |
| into the wrapper code for a system call. It should be used when size |
| of any argument > size of long int. */ |
| # undef INLINE_SYSCALL_TYPES |
| # define INLINE_SYSCALL_TYPES(name, nr, args...) \ |
| ({ \ |
| unsigned long int resultvar = INTERNAL_SYSCALL_TYPES (name, , nr, args); \ |
| if (__builtin_expect (INTERNAL_SYSCALL_ERROR_P (resultvar, ), 0)) \ |
| { \ |
| __set_errno (INTERNAL_SYSCALL_ERRNO (resultvar, )); \ |
| resultvar = (unsigned long int) -1; \ |
| } \ |
| (long int) resultvar; }) |
| |
| # undef INTERNAL_SYSCALL_DECL |
| # define INTERNAL_SYSCALL_DECL(err) do { } while (0) |
| |
| # define INTERNAL_SYSCALL_NCS(name, err, nr, args...) \ |
| ({ \ |
| unsigned long int resultvar; \ |
| LOAD_ARGS_##nr (args) \ |
| LOAD_REGS_##nr \ |
| asm volatile ( \ |
| "syscall\n\t" \ |
| : "=a" (resultvar) \ |
| : "0" (name) ASM_ARGS_##nr : "memory", "cc", "r11", "cx"); \ |
| (long int) resultvar; }) |
| # undef INTERNAL_SYSCALL |
| # define INTERNAL_SYSCALL(name, err, nr, args...) \ |
| INTERNAL_SYSCALL_NCS (__NR_##name, err, nr, ##args) |
| |
| # define INTERNAL_SYSCALL_NCS_TYPES(name, err, nr, args...) \ |
| ({ \ |
| unsigned long int resultvar; \ |
| LOAD_ARGS_TYPES_##nr (args) \ |
| LOAD_REGS_TYPES_##nr (args) \ |
| asm volatile ( \ |
| "syscall\n\t" \ |
| : "=a" (resultvar) \ |
| : "0" (name) ASM_ARGS_##nr : "memory", "cc", "r11", "cx"); \ |
| (long int) resultvar; }) |
| # undef INTERNAL_SYSCALL_TYPES |
| # define INTERNAL_SYSCALL_TYPES(name, err, nr, args...) \ |
| INTERNAL_SYSCALL_NCS_TYPES (__NR_##name, err, nr, ##args) |
| |
| # undef INTERNAL_SYSCALL_ERROR_P |
| # define INTERNAL_SYSCALL_ERROR_P(val, err) \ |
| ((unsigned long int) (long int) (val) >= -4095L) |
| |
| # undef INTERNAL_SYSCALL_ERRNO |
| # define INTERNAL_SYSCALL_ERRNO(val, err) (-(val)) |
| |
| # ifdef SHARED |
| # define INLINE_VSYSCALL(name, nr, args...) \ |
| ({ \ |
| __label__ out; \ |
| __label__ iserr; \ |
| INTERNAL_SYSCALL_DECL (sc_err); \ |
| long int sc_ret; \ |
| \ |
| __typeof (__vdso_##name) vdsop = __vdso_##name; \ |
| PTR_DEMANGLE (vdsop); \ |
| if (vdsop != NULL) \ |
| { \ |
| sc_ret = vdsop (args); \ |
| if (!INTERNAL_SYSCALL_ERROR_P (sc_ret, sc_err)) \ |
| goto out; \ |
| if (INTERNAL_SYSCALL_ERRNO (sc_ret, sc_err) != ENOSYS) \ |
| goto iserr; \ |
| } \ |
| \ |
| sc_ret = INTERNAL_SYSCALL (name, sc_err, nr, ##args); \ |
| if (INTERNAL_SYSCALL_ERROR_P (sc_ret, sc_err)) \ |
| { \ |
| iserr: \ |
| __set_errno (INTERNAL_SYSCALL_ERRNO (sc_ret, sc_err)); \ |
| sc_ret = -1L; \ |
| } \ |
| out: \ |
| sc_ret; \ |
| }) |
| # define INTERNAL_VSYSCALL(name, err, nr, args...) \ |
| ({ \ |
| __label__ out; \ |
| long int v_ret; \ |
| \ |
| __typeof (__vdso_##name) vdsop = __vdso_##name; \ |
| PTR_DEMANGLE (vdsop); \ |
| if (vdsop != NULL) \ |
| { \ |
| v_ret = vdsop (args); \ |
| if (!INTERNAL_SYSCALL_ERROR_P (v_ret, err) \ |
| || INTERNAL_SYSCALL_ERRNO (v_ret, err) != ENOSYS) \ |
| goto out; \ |
| } \ |
| v_ret = INTERNAL_SYSCALL (name, err, nr, ##args); \ |
| out: \ |
| v_ret; \ |
| }) |
| |
| # else |
| # define INLINE_VSYSCALL(name, nr, args...) \ |
| INLINE_SYSCALL (name, nr, ##args) |
| # define INTERNAL_VSYSCALL(name, err, nr, args...) \ |
| INTERNAL_SYSCALL (name, err, nr, ##args) |
| # endif |
| |
| # define LOAD_ARGS_0() |
| # define LOAD_REGS_0 |
| # define ASM_ARGS_0 |
| |
| # define LOAD_ARGS_TYPES_1(t1, a1) \ |
| t1 __arg1 = (t1) (a1); \ |
| LOAD_ARGS_0 () |
| # define LOAD_REGS_TYPES_1(t1, a1) \ |
| register t1 _a1 asm ("rdi") = __arg1; \ |
| LOAD_REGS_0 |
| # define ASM_ARGS_1 ASM_ARGS_0, "r" (_a1) |
| # define LOAD_ARGS_1(a1) \ |
| LOAD_ARGS_TYPES_1 (long int, a1) |
| # define LOAD_REGS_1 \ |
| LOAD_REGS_TYPES_1 (long int, a1) |
| |
| # define LOAD_ARGS_TYPES_2(t1, a1, t2, a2) \ |
| t2 __arg2 = (t2) (a2); \ |
| LOAD_ARGS_TYPES_1 (t1, a1) |
| # define LOAD_REGS_TYPES_2(t1, a1, t2, a2) \ |
| register t2 _a2 asm ("rsi") = __arg2; \ |
| LOAD_REGS_TYPES_1(t1, a1) |
| # define ASM_ARGS_2 ASM_ARGS_1, "r" (_a2) |
| # define LOAD_ARGS_2(a1, a2) \ |
| LOAD_ARGS_TYPES_2 (long int, a1, long int, a2) |
| # define LOAD_REGS_2 \ |
| LOAD_REGS_TYPES_2 (long int, a1, long int, a2) |
| |
| # define LOAD_ARGS_TYPES_3(t1, a1, t2, a2, t3, a3) \ |
| t3 __arg3 = (t3) (a3); \ |
| LOAD_ARGS_TYPES_2 (t1, a1, t2, a2) |
| # define LOAD_REGS_TYPES_3(t1, a1, t2, a2, t3, a3) \ |
| register t3 _a3 asm ("rdx") = __arg3; \ |
| LOAD_REGS_TYPES_2(t1, a1, t2, a2) |
| # define ASM_ARGS_3 ASM_ARGS_2, "r" (_a3) |
| # define LOAD_ARGS_3(a1, a2, a3) \ |
| LOAD_ARGS_TYPES_3 (long int, a1, long int, a2, long int, a3) |
| # define LOAD_REGS_3 \ |
| LOAD_REGS_TYPES_3 (long int, a1, long int, a2, long int, a3) |
| |
| # define LOAD_ARGS_TYPES_4(t1, a1, t2, a2, t3, a3, t4, a4) \ |
| t4 __arg4 = (t4) (a4); \ |
| LOAD_ARGS_TYPES_3 (t1, a1, t2, a2, t3, a3) |
| # define LOAD_REGS_TYPES_4(t1, a1, t2, a2, t3, a3, t4, a4) \ |
| register t4 _a4 asm ("r10") = __arg4; \ |
| LOAD_REGS_TYPES_3(t1, a2, t2, a2, t3, a3) |
| # define ASM_ARGS_4 ASM_ARGS_3, "r" (_a4) |
| # define LOAD_ARGS_4(a1, a2, a3, a4) \ |
| LOAD_ARGS_TYPES_4 (long int, a1, long int, a2, long int, a3, \ |
| long int, a4) |
| # define LOAD_REGS_4 \ |
| LOAD_REGS_TYPES_4 (long int, a1, long int, a2, long int, a3, \ |
| long int, a4) |
| |
| # define LOAD_ARGS_TYPES_5(t1, a1, t2, a2, t3, a3, t4, a4, t5, a5) \ |
| t5 __arg5 = (t5) (a5); \ |
| LOAD_ARGS_TYPES_4 (t1, a1, t2, a2, t3, a3, t4, a4) |
| # define LOAD_REGS_TYPES_5(t1, a1, t2, a2, t3, a3, t4, a4, t5, a5) \ |
| register t5 _a5 asm ("r8") = __arg5; \ |
| LOAD_REGS_TYPES_4 (t1, a1, t2, a2, t3, a3, t4, a4) |
| # define ASM_ARGS_5 ASM_ARGS_4, "r" (_a5) |
| # define LOAD_ARGS_5(a1, a2, a3, a4, a5) \ |
| LOAD_ARGS_TYPES_5 (long int, a1, long int, a2, long int, a3, \ |
| long int, a4, long int, a5) |
| # define LOAD_REGS_5 \ |
| LOAD_REGS_TYPES_5 (long int, a1, long int, a2, long int, a3, \ |
| long int, a4, long int, a5) |
| |
| # define LOAD_ARGS_TYPES_6(t1, a1, t2, a2, t3, a3, t4, a4, t5, a5, t6, a6) \ |
| t6 __arg6 = (t6) (a6); \ |
| LOAD_ARGS_TYPES_5 (t1, a1, t2, a2, t3, a3, t4, a4, t5, a5) |
| # define LOAD_REGS_TYPES_6(t1, a1, t2, a2, t3, a3, t4, a4, t5, a5, t6, a6) \ |
| register t6 _a6 asm ("r9") = __arg6; \ |
| LOAD_REGS_TYPES_5 (t1, a1, t2, a2, t3, a3, t4, a4, t5, a5) |
| # define ASM_ARGS_6 ASM_ARGS_5, "r" (_a6) |
| # define LOAD_ARGS_6(a1, a2, a3, a4, a5, a6) \ |
| LOAD_ARGS_TYPES_6 (long int, a1, long int, a2, long int, a3, \ |
| long int, a4, long int, a5, long int, a6) |
| # define LOAD_REGS_6 \ |
| LOAD_REGS_TYPES_6 (long int, a1, long int, a2, long int, a3, \ |
| long int, a4, long int, a5, long int, a6) |
| |
| #endif /* __ASSEMBLER__ */ |
| |
| |
| /* Pointer mangling support. */ |
| #if defined NOT_IN_libc && defined IS_IN_rtld |
| /* We cannot use the thread descriptor because in ld.so we use setjmp |
| earlier than the descriptor is initialized. */ |
| # ifdef __ASSEMBLER__ |
| # define PTR_MANGLE(reg) xor __pointer_chk_guard_local(%rip), reg; \ |
| rol $2*LP_SIZE+1, reg |
| # define PTR_DEMANGLE(reg) ror $2*LP_SIZE+1, reg; \ |
| xor __pointer_chk_guard_local(%rip), reg |
| # else |
| # define PTR_MANGLE(reg) asm ("xor __pointer_chk_guard_local(%%rip), %0\n" \ |
| "rol $2*" LP_SIZE "+1, %0" \ |
| : "=r" (reg) : "0" (reg)) |
| # define PTR_DEMANGLE(reg) asm ("ror $2*" LP_SIZE "+1, %0\n" \ |
| "xor __pointer_chk_guard_local(%%rip), %0" \ |
| : "=r" (reg) : "0" (reg)) |
| # endif |
| #else |
| # ifdef __ASSEMBLER__ |
| # define PTR_MANGLE(reg) xor %fs:POINTER_GUARD, reg; \ |
| rol $2*LP_SIZE+1, reg |
| # define PTR_DEMANGLE(reg) ror $2*LP_SIZE+1, reg; \ |
| xor %fs:POINTER_GUARD, reg |
| # else |
| # define PTR_MANGLE(var) asm ("xor %%fs:%c2, %0\n" \ |
| "rol $2*" LP_SIZE "+1, %0" \ |
| : "=r" (var) \ |
| : "0" (var), \ |
| "i" (offsetof (tcbhead_t, \ |
| pointer_guard))) |
| # define PTR_DEMANGLE(var) asm ("ror $2*" LP_SIZE "+1, %0\n" \ |
| "xor %%fs:%c2, %0" \ |
| : "=r" (var) \ |
| : "0" (var), \ |
| "i" (offsetof (tcbhead_t, \ |
| pointer_guard))) |
| # endif |
| #endif |
| |
| #endif /* linux/x86_64/sysdep.h */ |