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syscalls: Get rid of register variables

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It's been found that gcc 4.1.2 20080704 (Red Hat 4.1.2-48)
ignores register variables so to be on a safe side rewrite
syscalls with inline assembly without them.

nb: gcc version 4.6.1 20110908 (Red Hat 4.6.1-9) (GCC)
compiles them correctly.

Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
This commit is contained in:
Cyrill Gorcunov
2011-10-31 16:33:43 +04:00
parent 5b6748b4c9
commit bf41dcac48
1 changed files with 46 additions and 34 deletions
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80
include/syscall.h
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@@ -39,7 +39,7 @@ static always_inline long syscall2(int nr, unsigned long arg0, unsigned long arg
}
static always_inline long syscall3(int nr, unsigned long arg0, unsigned long arg1,
unsigned long arg2)
unsigned long arg2)
{
long ret;
asm volatile("syscall"
@@ -50,52 +50,64 @@ static always_inline long syscall3(int nr, unsigned long arg0, unsigned long arg
}
static always_inline long syscall4(int nr, unsigned long arg0, unsigned long arg1,
unsigned long arg2, unsigned long arg3)
unsigned long arg2, unsigned long arg3)
{
register unsigned long r10 asm("r10") = r10;
long ret;
r10 = arg3;
asm volatile("syscall"
: "=a" (ret)
: "a" (nr), "D" (arg0), "S" (arg1), "d" (arg2)
: "memory");
asm volatile(
"movl %1, %%eax \t\n"
"movq %2, %%rdi \t\n"
"movq %3, %%rsi \t\n"
"movq %4, %%rdx \t\n"
"movq %5, %%r10 \t\n"
"syscall \t\n"
"movq %%rax, %0 \t\n"
: "=r"(ret)
: "g" ((int)nr), "g" (arg0), "g" (arg1), "g" (arg2),
"g" (arg3)
: "rax", "rdi", "rsi", "rdx", "r10", "memory");
return ret;
}
static long always_inline syscall5(int nr, unsigned long arg0, unsigned long arg1,
unsigned long arg2, unsigned long arg3,
unsigned long arg4)
unsigned long arg2, unsigned long arg3,
unsigned long arg4)
{
register unsigned long r10 asm("r10") = r10;
register unsigned long r8 asm("r8") = r8;
long ret;
r10 = arg3;
r8 = arg4;
asm volatile("syscall"
: "=a" (ret)
: "a" (nr), "D" (arg0), "S" (arg1), "d" (arg2)
: "memory");
asm volatile(
"movl %1, %%eax \t\n"
"movq %2, %%rdi \t\n"
"movq %3, %%rsi \t\n"
"movq %4, %%rdx \t\n"
"movq %5, %%r10 \t\n"
"movq %6, %%r8 \t\n"
"syscall \t\n"
"movq %%rax, %0 \t\n"
: "=r"(ret)
: "g" ((int)nr), "g" (arg0), "g" (arg1), "g" (arg2),
"g" (arg3), "g" (arg4)
: "rax", "rdi", "rsi", "rdx", "r10", "r8", "memory");
return ret;
}
static long always_inline syscall6(int nr, unsigned long arg0, unsigned long arg1,
unsigned long arg2, unsigned long arg3,
unsigned long arg4, unsigned long arg5)
unsigned long arg2, unsigned long arg3,
unsigned long arg4, unsigned long arg5)
{
register unsigned long r10 asm("r10") = r10;
register unsigned long r8 asm("r8") = r8;
register unsigned long r9 asm("r9") = r9;
long ret;
r10 = arg3;
r8 = arg4;
r9 = arg5;
asm volatile("syscall"
: "=a" (ret)
: "a" (nr), "D" (arg0), "S" (arg1), "d" (arg2)
: "memory");
asm volatile(
"movl %1, %%eax \t\n"
"movq %2, %%rdi \t\n"
"movq %3, %%rsi \t\n"
"movq %4, %%rdx \t\n"
"movq %5, %%r10 \t\n"
"movq %6, %%r8 \t\n"
"movq %7, %%r9 \t\n"
"syscall \t\n"
"movq %%rax, %0 \t\n"
: "=r"(ret)
: "g" ((int)nr), "g" (arg0), "g" (arg1), "g" (arg2),
"g" (arg3), "g" (arg4), "g" (arg5)
: "rax", "rdi", "rsi", "rdx", "r10", "r8", "r9", "memory");
return ret;
}
@@ -105,7 +117,7 @@ static always_inline unsigned long sys_pause(void)
}
static always_inline unsigned long sys_mmap(void *addr, unsigned long len, unsigned long prot,
unsigned long flags, unsigned long fd, unsigned long offset)
unsigned long flags, unsigned long fd, unsigned long offset)
{
return syscall6(__NR_mmap, (unsigned long)addr,
len, prot, flags, fd, offset);