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syncthing-android/ext/patches/golang/386/0001-cmd-runtime-TLS-setup-for-android-386.patch

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7.5 KiB
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From df553e646c597ab7fb26e3ffa2b730c04ab069f8 Mon Sep 17 00:00:00 2001
From: Hyang-Ah Hana Kim <hyangah@gmail.com>
Date: Thu, 5 Nov 2015 16:32:27 -0500
Subject: [PATCH 1/4] cmd,runtime: TLS setup for android/386
Same ugly hack as https://go-review.googlesource.com/15991.
Update golang/go#9327.
Change-Id: I58284e83268a15de95eabc833c3e01bf1e3faa2e
---
src/cmd/internal/obj/x86/asm6.go | 3 ++
src/cmd/link/internal/ld/sym.go | 15 +++++--
src/runtime/cgo/gcc_android_386.c | 87 +++++++++++++++++++++++++++++++++++++++
src/runtime/cgo/gcc_linux_386.c | 12 ++++++
src/runtime/rt0_android_386.s | 39 ++++++++++++++++++
src/runtime/sys_linux_386.s | 10 +++++
6 files changed, 162 insertions(+), 4 deletions(-)
create mode 100644 src/runtime/cgo/gcc_android_386.c
create mode 100644 src/runtime/rt0_android_386.s
diff --git a/src/cmd/internal/obj/x86/asm6.go b/src/cmd/internal/obj/x86/asm6.go
index 919e00b..13ab240 100644
--- a/src/cmd/internal/obj/x86/asm6.go
+++ b/src/cmd/internal/obj/x86/asm6.go
@@ -1975,6 +1975,9 @@ func prefixof(ctxt *obj.Link, p *obj.Prog, a *obj.Addr) int {
if p.Mode == 32 {
switch ctxt.Headtype {
default:
+ if isAndroid {
+ return 0x65 // GS
+ }
log.Fatalf("unknown TLS base register for %s", obj.Headstr(ctxt.Headtype))
case obj.Hdarwin,
diff --git a/src/cmd/link/internal/ld/sym.go b/src/cmd/link/internal/ld/sym.go
index da5776d..d91f138 100644
--- a/src/cmd/link/internal/ld/sym.go
+++ b/src/cmd/link/internal/ld/sym.go
@@ -102,10 +102,17 @@ func linknew(arch *LinkArch) *Link {
obj.Hopenbsd,
obj.Hdragonfly,
obj.Hsolaris:
- if obj.Getgoos() == "android" && ctxt.Arch.Thechar == '6' {
- // Android/x86 constant - offset from 0(FS) to our
- // TLS slot. Explained in src/runtime/cgo/gcc_android_*.c
- ctxt.Tlsoffset = 0x1d0
+ if obj.Getgoos() == "android" {
+ switch ctxt.Arch.Thechar {
+ case '6':
+ // Android/x86 constant - offset from 0(FS) to our
+ // TLS slot. Explained in src/runtime/cgo/gcc_android_*.c
+ ctxt.Tlsoffset = 0x1d0
+ case '8':
+ ctxt.Tlsoffset = 0xf8
+ default:
+ ctxt.Tlsoffset = -1 * ctxt.Arch.Ptrsize
+ }
} else {
ctxt.Tlsoffset = -1 * ctxt.Arch.Ptrsize
}
diff --git a/src/runtime/cgo/gcc_android_386.c b/src/runtime/cgo/gcc_android_386.c
new file mode 100644
index 0000000..a82d7d0
--- /dev/null
+++ b/src/runtime/cgo/gcc_android_386.c
@@ -0,0 +1,87 @@
+// Copyright 2015 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#include <string.h> /* for strerror */
+#include <pthread.h>
+#include <signal.h>
+#include "libcgo.h"
+
+static void* threadentry(void*);
+static pthread_key_t k1;
+
+#define magic1 (0x23581321U)
+
+static void
+inittls(void)
+{
+ uint32 x;
+ pthread_key_t tofree[128], k;
+ int i, ntofree;
+
+ /*
+ * Same logic, code as gcc_android_amd64.c:/inittls.
+ * Note that this is a temporary hack that should be fixed soon.
+ *
+ * TODO: fix this.
+ *
+ * The linker and runtime hard-code this constant offset
+ * from %gs where we expect to find g. Disgusting.
+ *
+ * Known to src/cmd/link/internal/ld/sym.go:/0xf8
+ * and to src/runtime/sys_linux_386.s:/0xf8 or /GOOS_android.
+ * TODO(hyangah): check 0xb0 works with API23+
+ *
+ * As disgusting as on the darwin/386, darwin/amd64.
+ */
+ ntofree = 0;
+ for(;;) {
+ if(pthread_key_create(&k, nil) < 0) {
+ fprintf(stderr, "runtime/cgo: pthread_key_create failed\n");
+ abort();
+ }
+ pthread_setspecific(k, (void*)magic1);
+ asm volatile("movl %%gs:0xf8, %0" : "=r"(x));
+ pthread_setspecific(k, 0);
+ if (x == magic1) {
+ k1 = k;
+ break;
+ }
+ if(ntofree >= nelem(tofree)) {
+ fprintf(stderr, "runtime/cgo: could not obtain pthread_keys\n");
+ fprintf(stderr, "\ttried");
+ for(i=0; i<ntofree; i++)
+ fprintf(stderr, " %#x", (unsigned)tofree[i]);
+ fprintf(stderr, "\n");
+ abort();
+ }
+ tofree[ntofree++] = k;
+ }
+ // TODO: output to stderr is not useful for apps.
+ // Can we fall back to Android's log library?
+
+ /*
+ * We got the key we wanted. Free the others.
+ */
+ for(i=0; i<ntofree; i++) {
+ pthread_key_delete(tofree[i]);
+ }
+}
+
+
+static void*
+threadentry(void *v)
+{
+ ThreadStart ts;
+
+ ts = *(ThreadStart*)v;
+ free(v);
+
+ pthread_setspecific(k1, (void*)ts.g);
+
+ crosscall_386(ts.fn);
+ return nil;
+}
+
+void (*x_cgo_inittls)(void) = inittls;
+void* (*x_cgo_threadentry)(void*) = threadentry;
diff --git a/src/runtime/cgo/gcc_linux_386.c b/src/runtime/cgo/gcc_linux_386.c
index 9801c87..8fb7130 100644
--- a/src/runtime/cgo/gcc_linux_386.c
+++ b/src/runtime/cgo/gcc_linux_386.c
@@ -10,6 +10,10 @@
static void *threadentry(void*);
static void (*setg_gcc)(void*);
+// These will be set in gcc_android_386.c for android-specific customization.
+void (*x_cgo_inittls)(void);
+void* (*x_cgo_threadentry)(void*);
+
void
x_cgo_init(G *g, void (*setg)(void*))
{
@@ -21,6 +25,10 @@ x_cgo_init(G *g, void (*setg)(void*))
pthread_attr_getstacksize(&attr, &size);
g->stacklo = (uintptr)&attr - size + 4096;
pthread_attr_destroy(&attr);
+
+ if (x_cgo_inittls) {
+ x_cgo_inittls();
+ }
}
@@ -57,6 +65,10 @@ _cgo_sys_thread_start(ThreadStart *ts)
static void*
threadentry(void *v)
{
+ if (x_cgo_threadentry) {
+ return x_cgo_threadentry(v);
+ }
+
ThreadStart ts;
ts = *(ThreadStart*)v;
diff --git a/src/runtime/rt0_android_386.s b/src/runtime/rt0_android_386.s
new file mode 100644
index 0000000..bf44af3
--- /dev/null
+++ b/src/runtime/rt0_android_386.s
@@ -0,0 +1,39 @@
+// Copyright 2015 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#include "textflag.h"
+
+TEXT _rt0_386_android(SB),NOSPLIT,$8
+ MOVL 8(SP), AX // argc
+ LEAL 12(SP), BX // argv
+ MOVL AX, 0(SP)
+ MOVL BX, 4(SP)
+ CALL main(SB)
+ INT $3
+
+TEXT _rt0_386_android_lib(SB),NOSPLIT,$0
+ PUSHL $_rt0_386_android_argv(SB) // argv
+ PUSHL $1 // argc
+ CALL _rt0_386_linux_lib(SB)
+ POPL AX
+ POPL AX
+ RET
+
+DATA _rt0_386_android_argv+0x00(SB)/4,$_rt0_386_android_argv0(SB)
+DATA _rt0_386_android_argv+0x04(SB)/4,$0
+DATA _rt0_386_android_argv+0x08(SB)/4,$0
+DATA _rt0_386_android_argv+0x0c(SB)/4,$15 // AT_PLATFORM (auxvec.h)
+DATA _rt0_386_android_argv+0x10(SB)/4,$_rt0_386_android_auxv0(SB)
+DATA _rt0_386_android_argv+0x14(SB)/4,$0
+DATA _rt0_386_android_argv+0x18(SB)/4,$0
+DATA _rt0_386_android_argv+0x1c(SB)/4,$0
+GLOBL _rt0_386_android_argv(SB),NOPTR,$0x20
+
+// TODO: AT_HWCAP necessary? If so, what value?
+
+DATA _rt0_386_android_argv0(SB)/8, $"gojni"
+GLOBL _rt0_386_android_argv0(SB),RODATA,$8
+
+DATA _rt0_386_android_auxv0(SB)/8, $"i386"
+GLOBL _rt0_386_android_auxv0(SB),RODATA,$8
diff --git a/src/runtime/sys_linux_386.s b/src/runtime/sys_linux_386.s
index 9e0e87c..a52c4b2 100644
--- a/src/runtime/sys_linux_386.s
+++ b/src/runtime/sys_linux_386.s
@@ -405,6 +405,15 @@ TEXT runtime·setldt(SB),NOSPLIT,$32
MOVL entry+0(FP), BX // entry
MOVL address+4(FP), CX // base address
+#ifdef GOOS_android
+ /*
+ * Same as in sys_darwin_386.s:/ugliness, different constant.
+ * address currently holds m->tls, which must be %gs:0xf8.
+ * See cgo/gcc_android_386.c for the derivation of the constant.
+ */
+ SUBL $0xf8, CX
+ MOVL CX, 0(CX)
+#else
/*
* When linking against the system libraries,
* we use its pthread_create and let it set up %gs
@@ -420,6 +429,7 @@ TEXT runtime·setldt(SB),NOSPLIT,$32
*/
ADDL $0x4, CX // address
MOVL CX, 0(CX)
+#endif
// set up user_desc
LEAL 16(SP), AX // struct user_desc
--
2.5.2