summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorRich Felker <dalias@aerifal.cx>2012-10-11 22:47:07 -0400
committerRich Felker <dalias@aerifal.cx>2012-10-11 22:47:07 -0400
commit12e9b4faf68a1a02ebf5ad69c03ac10f170f14cb (patch)
treef206db332e670791be0120cb21cc5eee9bc23574
parentf2b1f1af83e96f8f98fbf2a5c663d8d058f2a66d (diff)
downloadmusl-12e9b4faf68a1a02ebf5ad69c03ac10f170f14cb.tar.gz
musl-12e9b4faf68a1a02ebf5ad69c03ac10f170f14cb.tar.bz2
musl-12e9b4faf68a1a02ebf5ad69c03ac10f170f14cb.tar.xz
musl-12e9b4faf68a1a02ebf5ad69c03ac10f170f14cb.zip
i386 vsyscall support (vdso-provided sysenter/syscall instruction based)
this doubles the performance of the fastest syscalls on the atom I tested it on; improvement is reportedly much more dramatic on worst-case cpus. cannot be used for cancellable syscalls.
-rw-r--r--arch/i386/syscall_arch.h73
-rw-r--r--src/env/__libc_start_main.c3
-rw-r--r--src/internal/i386/syscall.s74
-rw-r--r--src/internal/libc.c1
4 files changed, 69 insertions, 82 deletions
diff --git a/arch/i386/syscall_arch.h b/arch/i386/syscall_arch.h
index dc9ad147..2d64b0b0 100644
--- a/arch/i386/syscall_arch.h
+++ b/arch/i386/syscall_arch.h
@@ -8,111 +8,52 @@
static inline long __syscall0(long n)
{
unsigned long __ret;
- __asm__ __volatile__ ("int $128" : "=a"(__ret) : "a"(n) : "memory");
+ __asm__ __volatile__ ("call __vsyscall" : "=a"(__ret) : "a"(n) : "memory");
return __ret;
}
-#ifndef __PIC__
-
static inline long __syscall1(long n, long a1)
{
unsigned long __ret;
- __asm__ __volatile__ ("int $128" : "=a"(__ret) : "a"(n), "b"(a1) : "memory");
+ __asm__ __volatile__ ("call __vsyscall" : "=a"(__ret) : "a"(n), "d"(a1) : "memory");
return __ret;
}
static inline long __syscall2(long n, long a1, long a2)
{
unsigned long __ret;
- __asm__ __volatile__ ("int $128" : "=a"(__ret) : "a"(n), "b"(a1), "c"(a2) : "memory");
+ __asm__ __volatile__ ("call __vsyscall" : "=a"(__ret) : "a"(n), "d"(a1), "c"(a2) : "memory");
return __ret;
}
static inline long __syscall3(long n, long a1, long a2, long a3)
{
unsigned long __ret;
- __asm__ __volatile__ ("int $128" : "=a"(__ret) : "a"(n), "b"(a1), "c"(a2), "d"(a3) : "memory");
+ __asm__ __volatile__ ("call __vsyscall" : "=a"(__ret) : "a"(n), "d"(a1), "c"(a2), "D"(a3) : "memory");
return __ret;
}
static inline long __syscall4(long n, long a1, long a2, long a3, long a4)
{
unsigned long __ret;
- __asm__ __volatile__ ("int $128" : "=a"(__ret) : "a"(n), "b"(a1), "c"(a2), "d"(a3), "S"(a4) : "memory");
+ __asm__ __volatile__ ("call __vsyscall" : "=a"(__ret) : "a"(n), "d"(a1), "c"(a2), "D"(a3), "S"(a4) : "memory");
return __ret;
}
static inline long __syscall5(long n, long a1, long a2, long a3, long a4, long a5)
{
unsigned long __ret;
- __asm__ __volatile__ ("int $128" : "=a"(__ret) : "a"(n), "b"(a1), "c"(a2), "d"(a3), "S"(a4), "D"(a5) : "memory");
+ __asm__ __volatile__ ("push %6 ; call __vsyscall ; add $4,%%esp" : "=a"(__ret) : "a"(n), "d"(a1), "c"(a2), "D"(a3), "S"(a4), "g"(a5) : "memory");
return __ret;
}
static inline long __syscall6(long n, long a1, long a2, long a3, long a4, long a5, long a6)
{
unsigned long __ret;
- __asm__ __volatile__ ("pushl %7 ; pushl %%ebp ; mov 4(%%esp),%%ebp ; int $128 ; popl %%ebp ; popl %%ecx"
- : "=a"(__ret) : "a"(n), "b"(a1), "c"(a2), "d"(a3), "S"(a4), "D"(a5), "g"(a6) : "memory");
- return __ret;
-}
-
-#else
-
-static inline long __syscall1(long n, long a1)
-{
- unsigned long __ret;
- __asm__ __volatile__ ("xchg %2,%%ebx ; int $128 ; xchg %2,%%ebx"
- : "=a"(__ret) : "a"(n), "d"(a1) : "memory");
- return __ret;
-}
-
-static inline long __syscall2(long n, long a1, long a2)
-{
- unsigned long __ret;
- __asm__ __volatile__ ("xchg %2,%%ebx ; int $128 ; xchg %2,%%ebx"
- : "=a"(__ret) : "a"(n), "d"(a1), "c"(a2) : "memory");
- return __ret;
-}
-
-static inline long __syscall3(long n, long a1, long a2, long a3)
-{
- unsigned long __ret;
- __asm__ __volatile__ ("xchg %2,%%ebx ; int $128 ; xchg %2,%%ebx"
- : "=a"(__ret) : "a"(n), "S"(a1), "c"(a2), "d"(a3) : "memory");
+ __asm__ __volatile__ ("push %6 ; call __vsyscall6 ; add $4,%%esp" : "=a"(__ret) : "a"(n), "d"(a1), "c"(a2), "D"(a3), "S"(a4), "g"((long[]){a5, a6}) : "memory");
return __ret;
}
-static inline long __syscall4(long n, long a1, long a2, long a3, long a4)
-{
- unsigned long __ret;
- __asm__ __volatile__ ("xchg %2,%%ebx ; int $128 ; xchg %2,%%ebx"
- : "=a"(__ret) : "a"(n), "D"(a1), "c"(a2), "d"(a3), "S"(a4) : "memory");
- return __ret;
-}
-
-#if 0
-static inline long __syscall5(long n, long a1, long a2, long a3, long a4, long a5)
-{
- unsigned long __ret;
- __asm__ __volatile__ ("pushl %2 ; pushl %%ebx ; mov 4(%%esp),%%ebx ; int $128 ; popl %%ebx ; popl %%ecx"
- : "=a"(__ret) : "a"(n), "g"(a1), "c"(a2), "d"(a3), "S"(a4), "D"(a5) : "memory");
- return __ret;
-}
-#else
-static inline long __syscall5(long n, long a1, long a2, long a3, long a4, long a5)
-{
- return (__syscall)(n, a1, a2, a3, a4, a5);
-}
-#endif
-
-static inline long __syscall6(long n, long a1, long a2, long a3, long a4, long a5, long a6)
-{
- return (__syscall)(n, a1, a2, a3, a4, a5, a6);
-}
-
-#endif
-
#define __SC_socket 1
#define __SC_bind 2
diff --git a/src/env/__libc_start_main.c b/src/env/__libc_start_main.c
index e350fdb8..ee10b0de 100644
--- a/src/env/__libc_start_main.c
+++ b/src/env/__libc_start_main.c
@@ -6,6 +6,8 @@ void __init_security(size_t *);
#define AUX_CNT 38
+extern size_t __hwcap, __sysinfo;
+
void __init_libc(char **envp)
{
size_t i, *auxv, aux[AUX_CNT] = { 0 };
@@ -14,6 +16,7 @@ void __init_libc(char **envp)
libc.auxv = auxv = (void *)(envp+i+1);
for (i=0; auxv[i]; i+=2) if (auxv[i]<AUX_CNT) aux[auxv[i]] = auxv[i+1];
__hwcap = aux[AT_HWCAP];
+ __sysinfo = aux[AT_SYSINFO];
__init_tls(aux);
__init_security(aux);
diff --git a/src/internal/i386/syscall.s b/src/internal/i386/syscall.s
index 327d4cc0..79296ba0 100644
--- a/src/internal/i386/syscall.s
+++ b/src/internal/i386/syscall.s
@@ -1,20 +1,62 @@
+.hidden __sysinfo
+
+.global __vsyscall
+.type __vsyscall,@function
+__vsyscall:
+ push %edi
+ push %ebx
+ mov %edx,%ebx
+ mov %edi,%edx
+ mov 12(%esp),%edi
+ push %eax
+ call 1f
+2: pop %ebx
+ pop %ebx
+ pop %edi
+ ret
+
+1: mov (%esp),%eax
+ add $[__sysinfo-2b],%eax
+ mov (%eax),%eax
+ test %eax,%eax
+ jz 1f
+ push %eax
+ mov 8(%esp),%eax
+ ret
+1: mov 4(%esp),%eax
+ int $128
+ ret
+
+.global __vsyscall6
+.type __vsyscall6,@function
+__vsyscall6:
+ push %ebp
+ push %eax
+ mov 12(%esp), %ebp
+ mov (%ebp), %eax
+ mov 4(%ebp), %ebp
+ push %eax
+ mov 4(%esp),%eax
+ call __vsyscall
+ pop %ebp
+ pop %ebp
+ pop %ebp
+ ret
+
.global __syscall
.type __syscall,@function
__syscall:
- pushl %ebx
- pushl %esi
- pushl %edi
- pushl %ebp
- movl 20(%esp),%eax
- movl 24(%esp),%ebx
- movl 28(%esp),%ecx
- movl 32(%esp),%edx
- movl 36(%esp),%esi
- movl 40(%esp),%edi
- movl 44(%esp),%ebp
- int $128
- popl %ebp
- popl %edi
- popl %esi
- popl %ebx
+ lea 24(%esp),%eax
+ push %esi
+ push %edi
+ push %eax
+ mov 16(%esp),%eax
+ mov 20(%esp),%edx
+ mov 24(%esp),%ecx
+ mov 28(%esp),%edi
+ mov 32(%esp),%esi
+ call __vsyscall6
+ pop %edi
+ pop %edi
+ pop %esi
ret
diff --git a/src/internal/libc.c b/src/internal/libc.c
index 004c1a33..d22d2747 100644
--- a/src/internal/libc.c
+++ b/src/internal/libc.c
@@ -15,3 +15,4 @@ __asm__(".hidden __libc");
#endif
size_t __hwcap;
+size_t __sysinfo;