runtime: fix TLS handling for netbsd

Set the TLS base using the _lwp_setprivate() syscall, instead of via
sysarch(). NetBSD tracks the pointer passed to _lwp_setprivate() and
restores this value when restoring mcontext. If sysarch() is used
directly, restoring an mcontext trashes the FS/GS value, resulting
in a segfault when we next try to access the TLS.

R=golang-dev, r
CC=golang-dev
https://golang.org/cl/6206062

diff --git a/src/pkg/runtime/sys_netbsd_386.s b/src/pkg/runtime/sys_netbsd_386.s
index 018f4919781bc0e84dab1b3a8864042640bc2eea..139f20d0f7fc826d98ddc50f9ce989d236bc0482 100644 (file)
--- a/src/pkg/runtime/sys_netbsd_386.s
+++ b/src/pkg/runtime/sys_netbsd_386.s
@@ -12,14 +12,14 @@
 TEXT runtime·exit(SB),7,$-4
        MOVL    $1, AX
        INT     $0x80
-       MOVL    $0xf1, 0xf1  // crash
+       MOVL    $0xf1, 0xf1             // crash
        RET
 
 TEXT runtime·exit1(SB),7,$-4
        MOVL    $302, AX                // sys_threxit
        INT     $0x80
        JAE     2(PC)
-       MOVL    $0xf1, 0xf1  // crash
+       MOVL    $0xf1, 0xf1             // crash
        RET
 
 TEXT runtime·write(SB),7,$-4
@@ -79,7 +79,7 @@ TEXT runtime·munmap(SB),7,$-4
        MOVL    $73, AX                 // sys_munmap
        INT     $0x80
        JAE     2(PC)
-       MOVL    $0xf1, 0xf1  // crash
+       MOVL    $0xf1, 0xf1             // crash
        RET
 
 TEXT runtime·setitimer(SB),7,$-4
@@ -151,7 +151,7 @@ TEXT runtime·sigaction(SB),7,$24
        MOVL    $340, AX                // sys___sigaction_sigtramp
        INT     $0x80
        JAE     2(PC)
-       MOVL    $0xf1, 0xf1  // crash
+       MOVL    $0xf1, 0xf1             // crash
        RET
 
 TEXT runtime·sigtramp(SB),7,$44
@@ -193,7 +193,7 @@ TEXT runtime·sigtramp(SB),7,$44
        MOVL    AX, 4(SP)               // arg 1 - sigcontext
        MOVL    $103, AX                // sys_sigreturn
        INT     $0x80
-       MOVL    $0xf1, 0xf1  // crash
+       MOVL    $0xf1, 0xf1             // crash
        RET
 
 // int32 rfork_thread(int32 flags, void *stack, M *m, G *g, void (*fn)(void));
@@ -296,16 +296,14 @@ TEXT runtime·setldt(SB),7,$8
 
 TEXT runtime·settls(SB),7,$16
        // adjust for ELF: wants to use -8(GS) and -4(GS) for g and m
-       MOVL    20(SP), CX
+       MOVL    base+0(FP), CX
        ADDL    $8, CX
-       MOVL    CX, 0(CX)
        MOVL    $0, 0(SP)               // syscall gap
-       MOVL    $16, 4(SP)              // X86_SET_GSBASE (x86/sysarch.h)
-       MOVL    CX, 8(SP)               // pointer to base
-       MOVL    $165, AX                // sys_sysarch
+       MOVL    CX, 4(SP)               // arg 1 - ptr
+       MOVL    $317, AX                // sys__lwp_setprivate
        INT     $0x80
        JCC     2(PC)
-       MOVL    $0xf1, 0xf1  // crash
+       MOVL    $0xf1, 0xf1             // crash
        RET
 
 TEXT runtime·osyield(SB),7,$-4

diff --git a/src/pkg/runtime/sys_netbsd_amd64.s b/src/pkg/runtime/sys_netbsd_amd64.s
index c0c60ef0ce1a165e5a9e3bf671c55cdb9f29beb4..0f70f7cfa038f21feac2489fd4526434f797d3df 100644 (file)
--- a/src/pkg/runtime/sys_netbsd_amd64.s
+++ b/src/pkg/runtime/sys_netbsd_amd64.s
@@ -83,13 +83,13 @@ TEXT runtime·exit(SB),7,$-8
        MOVL    8(SP), DI               // arg 1 - exit status
        MOVL    $1, AX                  // sys_exit
        SYSCALL
-       MOVL    $0xf1, 0xf1  // crash
+       MOVL    $0xf1, 0xf1             // crash
        RET
 
 TEXT runtime·exit1(SB),7,$-8
        MOVL    $302, AX                // sys_threxit
        SYSCALL
-       MOVL    $0xf1, 0xf1  // crash
+       MOVL    $0xf1, 0xf1             // crash
        RET
 
 TEXT runtime·write(SB),7,$-8
@@ -179,10 +179,9 @@ TEXT runtime·sigaction(SB),7,$-8
        LEAQ    runtime·sigreturn_tramp(SB), R10
        MOVQ    $3, R8                  // arg 5 - version
        MOVL    $340, AX                // sys___sigaction_sigtramp
-
        SYSCALL
        JCC     2(PC)
-       MOVL    $0xf1, 0xf1  // crash
+       MOVL    $0xf1, 0xf1             // crash
        RET
 
 TEXT runtime·sigtramp(SB),7,$64
@@ -238,7 +237,7 @@ TEXT runtime·munmap(SB),7,$0
        MOVL    $73, AX                 // sys_munmap
        SYSCALL
        JCC     2(PC)
-       MOVL    $0xf1, 0xf1  // crash
+       MOVL    $0xf1, 0xf1             // crash
        RET
 
 TEXT runtime·sigaltstack(SB),7,$-8
@@ -247,20 +246,17 @@ TEXT runtime·sigaltstack(SB),7,$-8
        MOVQ    $281, AX                // sys___sigaltstack14
        SYSCALL
        JCC     2(PC)
-       MOVL    $0xf1, 0xf1  // crash
+       MOVL    $0xf1, 0xf1             // crash
        RET
 
 // set tls base to DI
 TEXT runtime·settls(SB),7,$8
        // adjust for ELF: wants to use -16(FS) and -8(FS) for g and m
-       ADDQ    $16, DI
-       MOVQ    DI, 0(SP)
-       MOVQ    SP, SI
-       MOVQ    $17, DI                 // X86_64_SET_FSBASE (x86/sysarch.h)
-       MOVQ    $165, AX                // sys_sysarch
+       ADDQ    $16, DI                 // arg 1 - ptr
+       MOVQ    $317, AX                // sys__lwp_setprivate
        SYSCALL
        JCC     2(PC)
-       MOVL    $0xf1, 0xf1  // crash
+       MOVL    $0xf1, 0xf1             // crash
        RET
 
 TEXT runtime·sysctl(SB),7,$0