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runtime, syscall: use int $0x80 to invoke syscalls on android/386 

golang.org/cl/16796 broke android/386 by assuming behaviour specific to glibc's
dynamic linker. Copy bionic by using int $0x80 to invoke syscalls on
android/386 as the old alternative (CALL *runtime_vdso(SB)) cannot be compiled
without text relocations, which we want to get rid of on android.

Also remove "CALL *runtime_vdso(SB)" variant from the syscall package.

Change-Id: I6c01849f8dcbd073d000ddc8f13948a836b8b261
Reviewed-on: https://go-review.googlesource.com/16996
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Crawshaw <crawshaw@golang.org>
Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>
This commit is contained in:
Michael Hudson-Doyle 2015-11-17 20:00:20 +13:00
parent f4a9bd87ba
commit 90e26f52c6
2 changed files with 73 additions and 47 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

93
src/runtime/sys_linux_386.s
View File

@ -10,17 +10,30 @@
#include "go_tls.h"
#include "textflag.h"
// Most linux systems use glibc's dynamic linker, which puts the
// __kernel_vsyscall vdso helper at 0x10(GS) for easy access from position
// independent code and setldt in this file does the same in the statically
// linked case. Android, however, uses bionic's dynamic linker, which does not
// save the helper anywhere, and so the only way to invoke a syscall from
// position independent code is boring old int $0x80 (which is also what
// bionic's syscall wrappers use).
#ifdef GOOS_android
#define INVOKE_SYSCALL INT $0x80
#else
#define INVOKE_SYSCALL CALL 0x10(GS)
#endif
TEXT runtime·exit(SB),NOSPLIT,$0
MOVL $252, AX // syscall number
MOVL code+0(FP), BX
CALL 0x10(GS)
INVOKE_SYSCALL
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 0x10(GS)
INVOKE_SYSCALL
INT $3 // not reached
RET
@ -29,7 +42,7 @@ TEXT runtime·open(SB),NOSPLIT,$0
MOVL name+0(FP), BX
MOVL mode+4(FP), CX
MOVL perm+8(FP), DX
CALL 0x10(GS)
INVOKE_SYSCALL
CMPL AX, $0xfffff001
JLS 2(PC)
MOVL $-1, AX
@ -39,7 +52,7 @@ TEXT runtime·open(SB),NOSPLIT,$0
TEXT runtime·closefd(SB),NOSPLIT,$0
MOVL $6, AX // syscall - close
MOVL fd+0(FP), BX
CALL 0x10(GS)
INVOKE_SYSCALL
CMPL AX, $0xfffff001
JLS 2(PC)
MOVL $-1, AX
@ -51,7 +64,7 @@ TEXT runtime·write(SB),NOSPLIT,$0
MOVL fd+0(FP), BX
MOVL p+4(FP), CX
MOVL n+8(FP), DX
CALL 0x10(GS)
INVOKE_SYSCALL
CMPL AX, $0xfffff001
JLS 2(PC)
MOVL $-1, AX
@ -63,7 +76,7 @@ TEXT runtime·read(SB),NOSPLIT,$0
MOVL fd+0(FP), BX
MOVL p+4(FP), CX
MOVL n+8(FP), DX
CALL 0x10(GS)
INVOKE_SYSCALL
CMPL AX, $0xfffff001
JLS 2(PC)
MOVL $-1, AX
@ -74,7 +87,7 @@ TEXT runtime·getrlimit(SB),NOSPLIT,$0
MOVL $191, AX // syscall - ugetrlimit
MOVL kind+0(FP), BX
MOVL limit+4(FP), CX
CALL 0x10(GS)
INVOKE_SYSCALL
MOVL AX, ret+8(FP)
RET
@ -93,31 +106,31 @@ TEXT runtime·usleep(SB),NOSPLIT,$8
MOVL $0, DX
MOVL $0, SI
LEAL 0(SP), DI
CALL 0x10(GS)
INVOKE_SYSCALL
RET
TEXT runtime·gettid(SB),NOSPLIT,$0-4
MOVL $224, AX // syscall - gettid
CALL 0x10(GS)
INVOKE_SYSCALL
MOVL AX, ret+0(FP)
RET
TEXT runtime·raise(SB),NOSPLIT,$12
MOVL $224, AX // syscall - gettid
CALL 0x10(GS)
INVOKE_SYSCALL
MOVL AX, BX // arg 1 tid
MOVL sig+0(FP), CX // arg 2 signal
MOVL $238, AX // syscall - tkill
CALL 0x10(GS)
INVOKE_SYSCALL
RET
TEXT runtime·raiseproc(SB),NOSPLIT,$12
MOVL $20, AX // syscall - getpid
CALL 0x10(GS)
INVOKE_SYSCALL
MOVL AX, BX // arg 1 pid
MOVL sig+0(FP), CX // arg 2 signal
MOVL $37, AX // syscall - kill
CALL 0x10(GS)
INVOKE_SYSCALL
RET
TEXT runtime·setitimer(SB),NOSPLIT,$0-12
@ -125,7 +138,7 @@ TEXT runtime·setitimer(SB),NOSPLIT,$0-12
MOVL mode+0(FP), BX
MOVL new+4(FP), CX
MOVL old+8(FP), DX
CALL 0x10(GS)
INVOKE_SYSCALL
RET
TEXT runtime·mincore(SB),NOSPLIT,$0-16
@ -133,7 +146,7 @@ TEXT runtime·mincore(SB),NOSPLIT,$0-16
MOVL addr+0(FP), BX
MOVL n+4(FP), CX
MOVL dst+8(FP), DX
CALL 0x10(GS)
INVOKE_SYSCALL
MOVL AX, ret+12(FP)
RET
@ -143,7 +156,7 @@ TEXT time·now(SB), NOSPLIT, $32
MOVL $0, BX // CLOCK_REALTIME
LEAL 8(SP), CX
MOVL $0, DX
CALL 0x10(GS)
INVOKE_SYSCALL
MOVL 8(SP), AX // sec
MOVL 12(SP), BX // nsec
@ -160,7 +173,7 @@ TEXT runtime·nanotime(SB), NOSPLIT, $32
MOVL $1, BX // CLOCK_MONOTONIC
LEAL 8(SP), CX
MOVL $0, DX
CALL 0x10(GS)
INVOKE_SYSCALL
MOVL 8(SP), AX // sec
MOVL 12(SP), BX // nsec
@ -181,7 +194,7 @@ TEXT runtime·rtsigprocmask(SB),NOSPLIT,$0
MOVL new+4(FP), CX
MOVL old+8(FP), DX
MOVL size+12(FP), SI
CALL 0x10(GS)
INVOKE_SYSCALL
CMPL AX, $0xfffff001
JLS 2(PC)
INT $3
@ -193,7 +206,7 @@ TEXT runtime·rt_sigaction(SB),NOSPLIT,$0
MOVL new+4(FP), CX
MOVL old+8(FP), DX
MOVL size+12(FP), SI
CALL 0x10(GS)
INVOKE_SYSCALL
MOVL AX, ret+16(FP)
RET
@ -235,7 +248,7 @@ TEXT runtime·mmap(SB),NOSPLIT,$0
MOVL fd+16(FP), DI
MOVL off+20(FP), BP
SHRL $12, BP
CALL 0x10(GS)
INVOKE_SYSCALL
CMPL AX, $0xfffff001
JLS 3(PC)
NOTL AX
@ -247,7 +260,7 @@ TEXT runtime·munmap(SB),NOSPLIT,$0
MOVL $91, AX // munmap
MOVL addr+0(FP), BX
MOVL n+4(FP), CX
CALL 0x10(GS)
INVOKE_SYSCALL
CMPL AX, $0xfffff001
JLS 2(PC)
INT $3
@ -258,7 +271,7 @@ TEXT runtime·madvise(SB),NOSPLIT,$0
MOVL addr+0(FP), BX
MOVL n+4(FP), CX
MOVL flags+8(FP), DX
CALL 0x10(GS)
INVOKE_SYSCALL
// ignore failure - maybe pages are locked
RET
@ -272,7 +285,7 @@ TEXT runtime·futex(SB),NOSPLIT,$0
MOVL ts+12(FP), SI
MOVL addr2+16(FP), DI
MOVL val3+20(FP), BP
CALL 0x10(GS)
INVOKE_SYSCALL
MOVL AX, ret+24(FP)
RET
@ -313,7 +326,7 @@ TEXT runtime·clone(SB),NOSPLIT,$0
// Initialize AX to Linux tid
MOVL $224, AX
CALL 0x10(GS)
INVOKE_SYSCALL
MOVL 0(SP), BX // m
MOVL 4(SP), DX // g
@ -364,7 +377,7 @@ TEXT runtime·sigaltstack(SB),NOSPLIT,$-8
MOVL $186, AX // sigaltstack
MOVL new+4(SP), BX
MOVL old+8(SP), CX
CALL 0x10(GS)
INVOKE_SYSCALL
CMPL AX, $0xfffff001
JLS 2(PC)
INT $3
@ -421,13 +434,13 @@ TEXT runtime·setldt(SB),NOSPLIT,$32
*/
ADDL $0x4, CX // address
MOVL CX, 0(CX)
#endif
// We copy the dynamic linker behaviour of storing the vsyscall entry point
// at 0x10(GS) so that it can be invoked by "CALL 0x10(GS)" in all
// situations, not only those where the binary is actually dynamically
// linked.
// We copy the glibc dynamic linker behaviour of storing the
// __kernel_vsyscall entry point at 0x10(GS) so that it can be invoked
// by "CALL 0x10(GS)" in all situations, not only those where the
// binary is actually dynamically linked.
MOVL runtime·_vdso(SB), AX
MOVL AX, 0x10(CX)
#endif
// set up user_desc
LEAL 16(SP), AX // struct user_desc
@ -459,7 +472,7 @@ TEXT runtime·setldt(SB),NOSPLIT,$32
TEXT runtime·osyield(SB),NOSPLIT,$0
MOVL $158, AX
CALL 0x10(GS)
INVOKE_SYSCALL
RET
TEXT runtime·sched_getaffinity(SB),NOSPLIT,$0
@ -467,7 +480,7 @@ TEXT runtime·sched_getaffinity(SB),NOSPLIT,$0
MOVL pid+0(FP), BX
MOVL len+4(FP), CX
MOVL buf+8(FP), DX
CALL 0x10(GS)
INVOKE_SYSCALL
MOVL AX, ret+12(FP)
RET
@ -475,7 +488,7 @@ TEXT runtime·sched_getaffinity(SB),NOSPLIT,$0
TEXT runtime·epollcreate(SB),NOSPLIT,$0
MOVL $254, AX
MOVL size+0(FP), BX
CALL 0x10(GS)
INVOKE_SYSCALL
MOVL AX, ret+4(FP)
RET
@ -483,7 +496,7 @@ TEXT runtime·epollcreate(SB),NOSPLIT,$0
TEXT runtime·epollcreate1(SB),NOSPLIT,$0
MOVL $329, AX
MOVL flags+0(FP), BX
CALL 0x10(GS)
INVOKE_SYSCALL
MOVL AX, ret+4(FP)
RET
@ -494,7 +507,7 @@ TEXT runtime·epollctl(SB),NOSPLIT,$0
MOVL op+4(FP), CX
MOVL fd+8(FP), DX
MOVL ev+12(FP), SI
CALL 0x10(GS)
INVOKE_SYSCALL
MOVL AX, ret+16(FP)
RET
@ -505,7 +518,7 @@ TEXT runtime·epollwait(SB),NOSPLIT,$0
MOVL ev+4(FP), CX
MOVL nev+8(FP), DX
MOVL timeout+12(FP), SI
CALL 0x10(GS)
INVOKE_SYSCALL
MOVL AX, ret+16(FP)
RET
@ -515,7 +528,7 @@ TEXT runtime·closeonexec(SB),NOSPLIT,$0
MOVL fd+0(FP), BX // fd
MOVL $2, CX // F_SETFD
MOVL $1, DX // FD_CLOEXEC
CALL 0x10(GS)
INVOKE_SYSCALL
RET
// int access(const char *name, int mode)
@ -523,7 +536,7 @@ TEXT runtime·access(SB),NOSPLIT,$0
MOVL $33, AX // syscall - access
MOVL name+0(FP), BX
MOVL mode+4(FP), CX
CALL 0x10(GS)
INVOKE_SYSCALL
MOVL AX, ret+8(FP)
RET
@ -534,7 +547,7 @@ TEXT runtime·connect(SB),NOSPLIT,$0-16
MOVL $102, AX // syscall - socketcall
MOVL $3, BX // connect
LEAL fd+0(FP), CX
CALL 0x10(GS)
INVOKE_SYSCALL
MOVL AX, ret+12(FP)
RET
@ -545,6 +558,6 @@ TEXT runtime·socket(SB),NOSPLIT,$0-16
MOVL $102, AX // syscall - socketcall
MOVL $1, BX // socket
LEAL domain+0(FP), CX
CALL 0x10(GS)
INVOKE_SYSCALL
MOVL AX, ret+12(FP)
RET

27
src/syscall/asm_linux_386.s
View File

@ -12,6 +12,19 @@
// func Syscall(trap uintptr, a1, a2, a3 uintptr) (r1, r2, err uintptr);
// Trap # in AX, args in BX CX DX SI DI, return in AX
// Most linux systems use glibc's dynamic linker, which puts the
// __kernel_vsyscall vdso helper at 0x10(GS) for easy access from position
// independent code and setldt in runtime does the same in the statically
// linked case. Android, however, uses bionic's dynamic linker, which does not
// save the helper anywhere, and so the only way to invoke a syscall from
// position independent code is boring old int $0x80 (which is also what
// bionic's syscall wrappers use).
#ifdef GOOS_android
#define INVOKE_SYSCALL INT $0x80
#else
#define INVOKE_SYSCALL CALL 0x10(GS)
#endif
TEXT ·Syscall(SB),NOSPLIT,$0-28
CALL runtime·entersyscall(SB)
MOVL trap+0(FP), AX // syscall entry
@ -20,7 +33,7 @@ TEXT ·Syscall(SB),NOSPLIT,$0-28
MOVL a3+12(FP), DX
MOVL $0, SI
MOVL $0, DI
CALL *runtime·_vdso(SB)
INVOKE_SYSCALL
CMPL AX, $0xfffff001
JLS ok
MOVL $-1, r1+16(FP)
@ -46,7 +59,7 @@ TEXT ·Syscall6(SB),NOSPLIT,$0-40
MOVL a4+16(FP), SI
MOVL a5+20(FP), DI
MOVL a6+24(FP), BP
CALL *runtime·_vdso(SB)
INVOKE_SYSCALL
CMPL AX, $0xfffff001
JLS ok6
MOVL $-1, r1+28(FP)
@ -70,7 +83,7 @@ TEXT ·RawSyscall(SB),NOSPLIT,$0-28
MOVL a3+12(FP), DX
MOVL $0, SI
MOVL $0, DI
CALL *runtime·_vdso(SB)
INVOKE_SYSCALL
CMPL AX, $0xfffff001
JLS ok1
MOVL $-1, r1+16(FP)
@ -93,7 +106,7 @@ TEXT ·RawSyscall6(SB),NOSPLIT,$0-40
MOVL a4+16(FP), SI
MOVL a5+20(FP), DI
MOVL a6+24(FP), BP
CALL *runtime·_vdso(SB)
INVOKE_SYSCALL
CMPL AX, $0xfffff001
JLS ok2
MOVL $-1, r1+28(FP)
@ -119,7 +132,7 @@ TEXT ·socketcall(SB),NOSPLIT,$0-36
MOVL $0, DX
MOVL $0, SI
MOVL $0, DI
CALL *runtime·_vdso(SB)
INVOKE_SYSCALL
CMPL AX, $0xfffff001
JLS oksock
MOVL $-1, n+28(FP)
@ -142,7 +155,7 @@ TEXT ·rawsocketcall(SB),NOSPLIT,$0-36
MOVL $0, DX
MOVL $0, SI
MOVL $0, DI
CALL *runtime·_vdso(SB)
INVOKE_SYSCALL
CMPL AX, $0xfffff001
JLS oksock1
MOVL $-1, n+28(FP)
@ -168,7 +181,7 @@ TEXT ·seek(SB),NOSPLIT,$0-28
MOVL offset_lo+4(FP), DX
LEAL newoffset_lo+16(FP), SI // result pointer
MOVL whence+12(FP), DI
CALL *runtime·_vdso(SB)
INVOKE_SYSCALL
CMPL AX, $0xfffff001
JLS okseek
MOVL $-1, newoffset_lo+16(FP)