runtime: invoke vsyscall helper via TCB when dynamic linking on linux/386

The dynamic linker on linux/386 stores the address of the vsyscall helper at a
fixed offset from the %gs register on linux/386 for easy access from PIC code.

Change-Id: I635305cfecceef2289985d62e676e16810ed6b94
Reviewed-on: https://go-review.googlesource.com/16346
Reviewed-by: Ian Lance Taylor <iant@golang.org>

diff --git a/src/runtime/sys_linux_386.s b/src/runtime/sys_linux_386.s
index 98a1a0ef6dc9db83efe30068adc9c343c46ef911..f2beb184550809ebb4b2cf14a313d7c475d91036 100644 (file)
--- a/src/runtime/sys_linux_386.s
+++ b/src/runtime/sys_linux_386.s
@@ -10,17 +10,23 @@
 #include "go_tls.h"
 #include "textflag.h"
 
+#ifdef shared
+#define INVOKE_SYSINFO CALL 0x10(GS)
+#else
+#define INVOKE_SYSINFO CALL *runtime·_vdso(SB)
+#endif
+
 TEXT runtime·exit(SB),NOSPLIT,$0
        MOVL    $252, AX        // syscall number
        MOVL    code+0(FP), BX
-       CALL    *runtime·_vdso(SB)
+       INVOKE_SYSINFO
        INT $3  // not reached
        RET
 
 TEXT runtime·exit1(SB),NOSPLIT,$0
        MOVL    $1, AX  // exit - exit the current os thread
        MOVL    code+0(FP), BX
-       CALL    *runtime·_vdso(SB)
+       INVOKE_SYSINFO
        INT $3  // not reached
        RET
 
@@ -29,7 +35,7 @@ TEXT runtime·open(SB),NOSPLIT,$0
        MOVL    name+0(FP), BX
        MOVL    mode+4(FP), CX
        MOVL    perm+8(FP), DX
-       CALL    *runtime·_vdso(SB)
+       INVOKE_SYSINFO
        CMPL    AX, $0xfffff001
        JLS     2(PC)
        MOVL    $-1, AX
@@ -39,7 +45,7 @@ TEXT runtime·open(SB),NOSPLIT,$0
 TEXT runtime·closefd(SB),NOSPLIT,$0
        MOVL    $6, AX          // syscall - close
        MOVL    fd+0(FP), BX
-       CALL    *runtime·_vdso(SB)
+       INVOKE_SYSINFO
        CMPL    AX, $0xfffff001
        JLS     2(PC)
        MOVL    $-1, AX
@@ -51,7 +57,7 @@ TEXT runtime·write(SB),NOSPLIT,$0
        MOVL    fd+0(FP), BX
        MOVL    p+4(FP), CX
        MOVL    n+8(FP), DX
-       CALL    *runtime·_vdso(SB)
+       INVOKE_SYSINFO
        CMPL    AX, $0xfffff001
        JLS     2(PC)
        MOVL    $-1, AX
@@ -63,7 +69,7 @@ TEXT runtime·read(SB),NOSPLIT,$0
        MOVL    fd+0(FP), BX
        MOVL    p+4(FP), CX
        MOVL    n+8(FP), DX
-       CALL    *runtime·_vdso(SB)
+       INVOKE_SYSINFO
        CMPL    AX, $0xfffff001
        JLS     2(PC)
        MOVL    $-1, AX
@@ -74,7 +80,7 @@ TEXT runtime·getrlimit(SB),NOSPLIT,$0
        MOVL    $191, AX                // syscall - ugetrlimit
        MOVL    kind+0(FP), BX
        MOVL    limit+4(FP), CX
-       CALL    *runtime·_vdso(SB)
+       INVOKE_SYSINFO
        MOVL    AX, ret+8(FP)
        RET
 
@@ -93,31 +99,31 @@ TEXT runtime·usleep(SB),NOSPLIT,$8
        MOVL    $0, DX
        MOVL    $0, SI
        LEAL    0(SP), DI
-       CALL    *runtime·_vdso(SB)
+       INVOKE_SYSINFO
        RET
 
 TEXT runtime·gettid(SB),NOSPLIT,$0-4
        MOVL    $224, AX        // syscall - gettid
-       CALL    *runtime·_vdso(SB)
+       INVOKE_SYSINFO
        MOVL    AX, ret+0(FP)
        RET
 
 TEXT runtime·raise(SB),NOSPLIT,$12
        MOVL    $224, AX        // syscall - gettid
-       CALL    *runtime·_vdso(SB)
+       INVOKE_SYSINFO
        MOVL    AX, BX  // arg 1 tid
        MOVL    sig+0(FP), CX   // arg 2 signal
        MOVL    $238, AX        // syscall - tkill
-       CALL    *runtime·_vdso(SB)
+       INVOKE_SYSINFO
        RET
 
 TEXT runtime·raiseproc(SB),NOSPLIT,$12
        MOVL    $20, AX // syscall - getpid
-       CALL    *runtime·_vdso(SB)
+       INVOKE_SYSINFO
        MOVL    AX, BX  // arg 1 pid
        MOVL    sig+0(FP), CX   // arg 2 signal
        MOVL    $37, AX // syscall - kill
-       CALL    *runtime·_vdso(SB)
+       INVOKE_SYSINFO
        RET
 
 TEXT runtime·setitimer(SB),NOSPLIT,$0-12
@@ -125,7 +131,7 @@ TEXT runtime·setitimer(SB),NOSPLIT,$0-12
        MOVL    mode+0(FP), BX
        MOVL    new+4(FP), CX
        MOVL    old+8(FP), DX
-       CALL    *runtime·_vdso(SB)
+       INVOKE_SYSINFO
        RET
 
 TEXT runtime·mincore(SB),NOSPLIT,$0-16
@@ -133,7 +139,7 @@ TEXT runtime·mincore(SB),NOSPLIT,$0-16
        MOVL    addr+0(FP), BX
        MOVL    n+4(FP), CX
        MOVL    dst+8(FP), DX
-       CALL    *runtime·_vdso(SB)
+       INVOKE_SYSINFO
        MOVL    AX, ret+12(FP)
        RET
 
@@ -143,7 +149,7 @@ TEXT time·now(SB), NOSPLIT, $32
        MOVL    $0, BX          // CLOCK_REALTIME
        LEAL    8(SP), CX
        MOVL    $0, DX
-       CALL    *runtime·_vdso(SB)
+       INVOKE_SYSINFO
        MOVL    8(SP), AX       // sec
        MOVL    12(SP), BX      // nsec
 
@@ -160,7 +166,7 @@ TEXT runtime·nanotime(SB), NOSPLIT, $32
        MOVL    $1, BX          // CLOCK_MONOTONIC
        LEAL    8(SP), CX
        MOVL    $0, DX
-       CALL    *runtime·_vdso(SB)
+       INVOKE_SYSINFO
        MOVL    8(SP), AX       // sec
        MOVL    12(SP), BX      // nsec
 
@@ -181,7 +187,7 @@ TEXT runtime·rtsigprocmask(SB),NOSPLIT,$0
        MOVL    new+4(FP), CX
        MOVL    old+8(FP), DX
        MOVL    size+12(FP), SI
-       CALL    *runtime·_vdso(SB)
+       INVOKE_SYSINFO
        CMPL    AX, $0xfffff001
        JLS     2(PC)
        INT $3
@@ -193,7 +199,7 @@ TEXT runtime·rt_sigaction(SB),NOSPLIT,$0
        MOVL    new+4(FP), CX
        MOVL    old+8(FP), DX
        MOVL    size+12(FP), SI
-       CALL    *runtime·_vdso(SB)
+       INVOKE_SYSINFO
        MOVL    AX, ret+16(FP)
        RET
 
@@ -235,7 +241,7 @@ TEXT runtime·mmap(SB),NOSPLIT,$0
        MOVL    fd+16(FP), DI
        MOVL    off+20(FP), BP
        SHRL    $12, BP
-       CALL    *runtime·_vdso(SB)
+       INVOKE_SYSINFO
        CMPL    AX, $0xfffff001
        JLS     3(PC)
        NOTL    AX
@@ -247,7 +253,7 @@ TEXT runtime·munmap(SB),NOSPLIT,$0
        MOVL    $91, AX // munmap
        MOVL    addr+0(FP), BX
        MOVL    n+4(FP), CX
-       CALL    *runtime·_vdso(SB)
+       INVOKE_SYSINFO
        CMPL    AX, $0xfffff001
        JLS     2(PC)
        INT $3
@@ -258,7 +264,7 @@ TEXT runtime·madvise(SB),NOSPLIT,$0
        MOVL    addr+0(FP), BX
        MOVL    n+4(FP), CX
        MOVL    flags+8(FP), DX
-       CALL    *runtime·_vdso(SB)
+       INVOKE_SYSINFO
        // ignore failure - maybe pages are locked
        RET
 
@@ -272,7 +278,7 @@ TEXT runtime·futex(SB),NOSPLIT,$0
        MOVL    ts+12(FP), SI
        MOVL    addr2+16(FP), DI
        MOVL    val3+20(FP), BP
-       CALL    *runtime·_vdso(SB)
+       INVOKE_SYSINFO
        MOVL    AX, ret+24(FP)
        RET
 
@@ -314,7 +320,7 @@ TEXT runtime·clone(SB),NOSPLIT,$0
 
        // Initialize AX to Linux tid
        MOVL    $224, AX
-       CALL    *runtime·_vdso(SB)
+       INVOKE_SYSINFO
 
        MOVL    0(SP), BX           // m
        MOVL    4(SP), DX           // g
@@ -366,7 +372,7 @@ TEXT runtime·sigaltstack(SB),NOSPLIT,$-8
        MOVL    $186, AX        // sigaltstack
        MOVL    new+4(SP), BX
        MOVL    old+8(SP), CX
-       CALL    *runtime·_vdso(SB)
+       INVOKE_SYSINFO
        CMPL    AX, $0xfffff001
        JLS     2(PC)
        INT     $3
@@ -427,7 +433,7 @@ TEXT runtime·setldt(SB),NOSPLIT,$32
        MOVL    AX, CX  // user_desc
        MOVL    $16, DX // sizeof(user_desc)
        MOVL    $123, AX        // syscall - modify_ldt
-       CALL    *runtime·_vdso(SB)
+       INVOKE_SYSINFO
 
        // breakpoint on error
        CMPL AX, $0xfffff001
@@ -444,7 +450,7 @@ TEXT runtime·setldt(SB),NOSPLIT,$32
 
 TEXT runtime·osyield(SB),NOSPLIT,$0
        MOVL    $158, AX
-       CALL    *runtime·_vdso(SB)
+       INVOKE_SYSINFO
        RET
 
 TEXT runtime·sched_getaffinity(SB),NOSPLIT,$0
@@ -452,7 +458,7 @@ TEXT runtime·sched_getaffinity(SB),NOSPLIT,$0
        MOVL    pid+0(FP), BX
        MOVL    len+4(FP), CX
        MOVL    buf+8(FP), DX
-       CALL    *runtime·_vdso(SB)
+       INVOKE_SYSINFO
        MOVL    AX, ret+12(FP)
        RET
 
@@ -460,7 +466,7 @@ TEXT runtime·sched_getaffinity(SB),NOSPLIT,$0
 TEXT runtime·epollcreate(SB),NOSPLIT,$0
        MOVL    $254, AX
        MOVL    size+0(FP), BX
-       CALL    *runtime·_vdso(SB)
+       INVOKE_SYSINFO
        MOVL    AX, ret+4(FP)
        RET
 
@@ -468,7 +474,7 @@ TEXT runtime·epollcreate(SB),NOSPLIT,$0
 TEXT runtime·epollcreate1(SB),NOSPLIT,$0
        MOVL    $329, AX
        MOVL    flags+0(FP), BX
-       CALL    *runtime·_vdso(SB)
+       INVOKE_SYSINFO
        MOVL    AX, ret+4(FP)
        RET
 
@@ -479,7 +485,7 @@ TEXT runtime·epollctl(SB),NOSPLIT,$0
        MOVL    op+4(FP), CX
        MOVL    fd+8(FP), DX
        MOVL    ev+12(FP), SI
-       CALL    *runtime·_vdso(SB)
+       INVOKE_SYSINFO
        MOVL    AX, ret+16(FP)
        RET
 
@@ -490,7 +496,7 @@ TEXT runtime·epollwait(SB),NOSPLIT,$0
        MOVL    ev+4(FP), CX
        MOVL    nev+8(FP), DX
        MOVL    timeout+12(FP), SI
-       CALL    *runtime·_vdso(SB)
+       INVOKE_SYSINFO
        MOVL    AX, ret+16(FP)
        RET
 
@@ -500,5 +506,5 @@ TEXT runtime·closeonexec(SB),NOSPLIT,$0
        MOVL    fd+0(FP), BX  // fd
        MOVL    $2, CX  // F_SETFD
        MOVL    $1, DX  // FD_CLOEXEC
-       CALL    *runtime·_vdso(SB)
+       INVOKE_SYSINFO
        RET