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bdb0817599
we have to avoid using ebx unconditionally in asm constraints for
i386, because gcc 3 and 4 and possibly other simplistic compilers
(pcc?) implement PIC via making ebx a fixed-use register, and disallow
its use for anything else. rather than hard-coding knowledge of which
compilers work (at least gcc 5+ and clang), perform a configure test;
this should give us the good codegen on any new compilers we don't yet
know about.
swapping ebx and edx is kept for 1- and 2-arg syscalls because it
avoids having any spills/stack-frame at all in small functions. for
6-arg, if ebx is directly usable, the complex shuffling introduced in
commit c8798ef974 can be avoided, and
ebp can be loaded the same way ebx is in 5-arg syscalls for compilers
that don't support direct use of ebx.
90 lines
3.0 KiB
C
90 lines
3.0 KiB
C
#define __SYSCALL_LL_E(x) \
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((union { long long ll; long l[2]; }){ .ll = x }).l[0], \
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((union { long long ll; long l[2]; }){ .ll = x }).l[1]
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#define __SYSCALL_LL_O(x) __SYSCALL_LL_E((x))
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#if SYSCALL_NO_TLS
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#define SYSCALL_INSNS "int $128"
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#else
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#define SYSCALL_INSNS "call *%%gs:16"
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#endif
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#define SYSCALL_INSNS_12 "xchg %%ebx,%%edx ; " SYSCALL_INSNS " ; xchg %%ebx,%%edx"
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#define SYSCALL_INSNS_34 "xchg %%ebx,%%edi ; " SYSCALL_INSNS " ; xchg %%ebx,%%edi"
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static inline long __syscall0(long n)
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{
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unsigned long __ret;
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__asm__ __volatile__ (SYSCALL_INSNS : "=a"(__ret) : "a"(n) : "memory");
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return __ret;
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}
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static inline long __syscall1(long n, long a1)
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{
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unsigned long __ret;
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__asm__ __volatile__ (SYSCALL_INSNS_12 : "=a"(__ret) : "a"(n), "d"(a1) : "memory");
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return __ret;
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}
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static inline long __syscall2(long n, long a1, long a2)
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{
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unsigned long __ret;
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__asm__ __volatile__ (SYSCALL_INSNS_12 : "=a"(__ret) : "a"(n), "d"(a1), "c"(a2) : "memory");
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return __ret;
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}
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static inline long __syscall3(long n, long a1, long a2, long a3)
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{
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unsigned long __ret;
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#if !defined(__PIC__) || !defined(BROKEN_EBX_ASM)
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__asm__ __volatile__ (SYSCALL_INSNS : "=a"(__ret) : "a"(n), "b"(a1), "c"(a2), "d"(a3) : "memory");
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#else
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__asm__ __volatile__ (SYSCALL_INSNS_34 : "=a"(__ret) : "a"(n), "D"(a1), "c"(a2), "d"(a3) : "memory");
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#endif
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return __ret;
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}
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static inline long __syscall4(long n, long a1, long a2, long a3, long a4)
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{
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unsigned long __ret;
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#if !defined(__PIC__) || !defined(BROKEN_EBX_ASM)
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__asm__ __volatile__ (SYSCALL_INSNS : "=a"(__ret) : "a"(n), "b"(a1), "c"(a2), "d"(a3), "S"(a4) : "memory");
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#else
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__asm__ __volatile__ (SYSCALL_INSNS_34 : "=a"(__ret) : "a"(n), "D"(a1), "c"(a2), "d"(a3), "S"(a4) : "memory");
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#endif
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return __ret;
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}
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static inline long __syscall5(long n, long a1, long a2, long a3, long a4, long a5)
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{
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unsigned long __ret;
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#if !defined(__PIC__) || !defined(BROKEN_EBX_ASM)
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__asm__ __volatile__ (SYSCALL_INSNS
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: "=a"(__ret) : "a"(n), "b"(a1), "c"(a2), "d"(a3), "S"(a4), "D"(a5) : "memory");
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#else
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__asm__ __volatile__ ("pushl %2 ; push %%ebx ; mov 4(%%esp),%%ebx ; " SYSCALL_INSNS " ; pop %%ebx ; add $4,%%esp"
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: "=a"(__ret) : "a"(n), "g"(a1), "c"(a2), "d"(a3), "S"(a4), "D"(a5) : "memory");
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#endif
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return __ret;
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}
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static inline long __syscall6(long n, long a1, long a2, long a3, long a4, long a5, long a6)
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{
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unsigned long __ret;
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#if !defined(__PIC__) || !defined(BROKEN_EBX_ASM)
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__asm__ __volatile__ ("pushl %7 ; push %%ebp ; mov 4(%%esp),%%ebp ; " SYSCALL_INSNS " ; pop %%ebp ; add $4,%%esp"
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: "=a"(__ret) : "a"(n), "b"(a1), "c"(a2), "d"(a3), "S"(a4), "D"(a5), "g"(a6) : "memory");
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#else
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unsigned long a1a6[2] = { a1, a6 };
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__asm__ __volatile__ ("pushl %1 ; push %%ebx ; push %%ebp ; mov 8(%%esp),%%ebx ; mov 4(%%ebx),%%ebp ; mov (%%ebx),%%ebx ; " SYSCALL_INSNS " ; pop %%ebp ; pop %%ebx ; add $4,%%esp"
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: "=a"(__ret) : "g"(&a1a6), "a"(n), "c"(a2), "d"(a3), "S"(a4), "D"(a5) : "memory");
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#endif
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return __ret;
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}
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#define VDSO_USEFUL
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#define VDSO_CGT_SYM "__vdso_clock_gettime"
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#define VDSO_CGT_VER "LINUX_2.6"
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#define SYSCALL_USE_SOCKETCALL
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