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1 /* Copyright (C) 2001-2005, 2007 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Lesser General Public
6 License as published by the Free Software Foundation; either
7 version 2.1 of the License, or (at your option) any later version.
9 The GNU C Library is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 Lesser General Public License for more details.
14 You should have received a copy of the GNU Lesser General Public
15 License along with the GNU C Library; if not, write to the Free
16 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
19 #ifndef _LINUX_X86_64_SYSDEP_H
20 #define _LINUX_X86_64_SYSDEP_H 1
22 /* There is some commonality. */
23 #include <sysdeps/unix/x86_64/sysdep.h>
29 # include <dl-sysdep.h> /* Defines RTLD_PRIVATE_ERRNO. */
32 /* For Linux we can use the system call table in the header file
33 /usr/include/asm/unistd.h
34 of the kernel. But these symbols do not follow the SYS_* syntax
35 so we have to redefine the `SYS_ify' macro here. */
37 #define SYS_ify(syscall_name) __NR_##syscall_name
39 /* This is a kludge to make syscalls.list find these under the names
40 pread and pwrite, since some kernel headers define those names
41 and some define the *64 names for the same system calls. */
42 #if !defined __NR_pread && defined __NR_pread64
43 # define __NR_pread __NR_pread64
45 #if !defined __NR_pwrite && defined __NR_pwrite64
46 # define __NR_pwrite __NR_pwrite64
49 /* This is to help the old kernel headers where __NR_semtimedop is not
51 #ifndef __NR_semtimedop
52 # define __NR_semtimedop 220
58 /* Linux uses a negative return value to indicate syscall errors,
59 unlike most Unices, which use the condition codes' carry flag.
61 Since version 2.1 the return value of a system call might be
62 negative even if the call succeeded. E.g., the `lseek' system call
63 might return a large offset. Therefore we must not anymore test
64 for < 0, but test for a real error by making sure the value in %eax
65 is a real error number. Linus said he will make sure the no syscall
66 returns a value in -1 .. -4095 as a valid result so we can savely
69 /* We don't want the label for the error handle to be global when we define
72 # define SYSCALL_ERROR_LABEL 0f
74 # define SYSCALL_ERROR_LABEL syscall_error
78 #define PSEUDO(name, syscall_name, args) \
81 DO_CALL (syscall_name, args); \
83 jae SYSCALL_ERROR_LABEL; \
87 #define PSEUDO_END(name) \
88 SYSCALL_ERROR_HANDLER \
92 #define PSEUDO_NOERRNO(name, syscall_name, args) \
95 DO_CALL (syscall_name, args)
97 #undef PSEUDO_END_NOERRNO
98 #define PSEUDO_END_NOERRNO(name) \
101 #define ret_NOERRNO ret
104 #define PSEUDO_ERRVAL(name, syscall_name, args) \
107 DO_CALL (syscall_name, args); \
110 #undef PSEUDO_END_ERRVAL
111 #define PSEUDO_END_ERRVAL(name) \
114 #define ret_ERRVAL ret
117 #define SYSCALL_ERROR_HANDLER /* Nothing here; code in sysdep.S is used. */
118 #elif RTLD_PRIVATE_ERRNO
119 # define SYSCALL_ERROR_HANDLER \
121 leaq rtld_errno(%rip), %rcx; \
129 # define SYSCALL_ERROR_ERRNO __libc_errno
131 # define SYSCALL_ERROR_ERRNO errno
133 # define SYSCALL_ERROR_HANDLER \
135 movq SYSCALL_ERROR_ERRNO@GOTTPOFF(%rip), %rcx;\
138 movl %edx, %fs:(%rcx); \
141 #elif defined _LIBC_REENTRANT
142 /* Store (- %rax) into errno through the GOT.
143 Note that errno occupies only 4 bytes. */
144 # define SYSCALL_ERROR_HANDLER \
149 cfi_adjust_cfa_offset(8); \
150 PUSH_ERRNO_LOCATION_RETURN; \
151 call BP_SYM (__errno_location)@PLT; \
152 POP_ERRNO_LOCATION_RETURN; \
154 cfi_adjust_cfa_offset(-8); \
159 /* A quick note: it is assumed that the call to `__errno_location' does
160 not modify the stack! */
161 #else /* Not _LIBC_REENTRANT. */
162 # define SYSCALL_ERROR_HANDLER \
163 0:movq errno@GOTPCREL(%RIP), %rcx; \
171 /* The Linux/x86-64 kernel expects the system call parameters in
172 registers according to the following table:
182 The Linux kernel uses and destroys internally these registers:
185 eflags from syscall r11
187 Normal function call, including calls to the system call stub
188 functions in the libc, get the first six parameters passed in
189 registers and the seventh parameter and later on the stack. The
190 register use is as follows:
192 system call number in the DO_CALL macro
200 We have to take care that the stack is aligned to 16 bytes. When
201 called the stack is not aligned since the return address has just
205 Syscalls of more than 6 arguments are not supported. */
208 #define DO_CALL(syscall_name, args) \
210 movl $SYS_ify (syscall_name), %eax; \
213 #define DOARGS_0 /* nothing */
214 #define DOARGS_1 /* nothing */
215 #define DOARGS_2 /* nothing */
216 #define DOARGS_3 /* nothing */
217 #define DOARGS_4 movq %rcx, %r10;
218 #define DOARGS_5 DOARGS_4
219 #define DOARGS_6 DOARGS_5
221 #else /* !__ASSEMBLER__ */
222 /* Define a macro which expands inline into the wrapper code for a system
224 #undef INLINE_SYSCALL
225 #define INLINE_SYSCALL(name, nr, args...) \
227 unsigned long resultvar = INTERNAL_SYSCALL (name, , nr, args); \
228 if (__builtin_expect (INTERNAL_SYSCALL_ERROR_P (resultvar, ), 0)) \
230 __set_errno (INTERNAL_SYSCALL_ERRNO (resultvar, )); \
231 resultvar = (unsigned long) -1; \
235 #undef INTERNAL_SYSCALL_DECL
236 #define INTERNAL_SYSCALL_DECL(err) do { } while (0)
238 #define INTERNAL_SYSCALL_NCS(name, err, nr, args...) \
240 unsigned long resultvar; \
241 LOAD_ARGS_##nr (args) \
246 : "0" (name) ASM_ARGS_##nr : "memory", "cc", "r11", "cx"); \
248 #undef INTERNAL_SYSCALL
249 #define INTERNAL_SYSCALL(name, err, nr, args...) \
250 INTERNAL_SYSCALL_NCS (__NR_##name, err, nr, ##args)
252 #undef INTERNAL_SYSCALL_ERROR_P
253 #define INTERNAL_SYSCALL_ERROR_P(val, err) \
254 ((unsigned long) (val) >= -4095L)
256 #undef INTERNAL_SYSCALL_ERRNO
257 #define INTERNAL_SYSCALL_ERRNO(val, err) (-(val))
259 #define LOAD_ARGS_0()
263 #define LOAD_ARGS_1(a1) \
264 long int __arg1 = (long) (a1); \
266 #define LOAD_REGS_1 \
267 register long int _a1 asm ("rdi") = __arg1; \
269 #define ASM_ARGS_1 ASM_ARGS_0, "r" (_a1)
271 #define LOAD_ARGS_2(a1, a2) \
272 long int __arg2 = (long) (a2); \
274 #define LOAD_REGS_2 \
275 register long int _a2 asm ("rsi") = __arg2; \
277 #define ASM_ARGS_2 ASM_ARGS_1, "r" (_a2)
279 #define LOAD_ARGS_3(a1, a2, a3) \
280 long int __arg3 = (long) (a3); \
282 #define LOAD_REGS_3 \
283 register long int _a3 asm ("rdx") = __arg3; \
285 #define ASM_ARGS_3 ASM_ARGS_2, "r" (_a3)
287 #define LOAD_ARGS_4(a1, a2, a3, a4) \
288 long int __arg4 = (long) (a4); \
289 LOAD_ARGS_3 (a1, a2, a3)
290 #define LOAD_REGS_4 \
291 register long int _a4 asm ("r10") = __arg4; \
293 #define ASM_ARGS_4 ASM_ARGS_3, "r" (_a4)
295 #define LOAD_ARGS_5(a1, a2, a3, a4, a5) \
296 long int __arg5 = (long) (a5); \
297 LOAD_ARGS_4 (a1, a2, a3, a4)
298 #define LOAD_REGS_5 \
299 register long int _a5 asm ("r8") = __arg5; \
301 #define ASM_ARGS_5 ASM_ARGS_4, "r" (_a5)
303 #define LOAD_ARGS_6(a1, a2, a3, a4, a5, a6) \
304 long int __arg6 = (long) (a6); \
305 LOAD_ARGS_5 (a1, a2, a3, a4, a5)
306 #define LOAD_REGS_6 \
307 register long int _a6 asm ("r9") = __arg6; \
309 #define ASM_ARGS_6 ASM_ARGS_5, "r" (_a6)
311 #endif /* __ASSEMBLER__ */
314 /* Pointer mangling support. */
315 #if defined NOT_IN_libc && defined IS_IN_rtld
316 /* We cannot use the thread descriptor because in ld.so we use setjmp
317 earlier than the descriptor is initialized. */
318 # ifdef __ASSEMBLER__
319 # define PTR_MANGLE(reg) xorq __pointer_chk_guard_local(%rip), reg; \
321 # define PTR_DEMANGLE(reg) rorq $17, reg; \
322 xorq __pointer_chk_guard_local(%rip), reg
324 # define PTR_MANGLE(reg) asm ("xorq __pointer_chk_guard_local(%%rip), %0\n" \
326 : "=r" (reg) : "0" (reg))
327 # define PTR_DEMANGLE(reg) asm ("rorq $17, %0\n" \
328 "xorq __pointer_chk_guard_local(%%rip), %0" \
329 : "=r" (reg) : "0" (reg))
332 # ifdef __ASSEMBLER__
333 # define PTR_MANGLE(reg) xorq %fs:POINTER_GUARD, reg; \
335 # define PTR_DEMANGLE(reg) rorq $17, reg; \
336 xorq %fs:POINTER_GUARD, reg
338 # define PTR_MANGLE(var) asm ("xorq %%fs:%c2, %0\n" \
342 "i" (offsetof (tcbhead_t, \
344 # define PTR_DEMANGLE(var) asm ("rorq $17, %0\n" \
345 "xorq %%fs:%c2, %0" \
348 "i" (offsetof (tcbhead_t, \
353 #endif /* linux/x86_64/sysdep.h */