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-rw-r--r--src/cmd/internal/obj/x86/asm6.go46
-rw-r--r--src/cmd/internal/obj/x86/obj6.go18
-rw-r--r--src/runtime/asm_386.s19
-rw-r--r--src/runtime/cgo/gcc_windows_386.c12
-rw-r--r--src/runtime/sys_windows_386.s46
5 files changed, 84 insertions, 57 deletions
diff --git a/src/cmd/internal/obj/x86/asm6.go b/src/cmd/internal/obj/x86/asm6.go
index 953eedc0d0..de08b42ab5 100644
--- a/src/cmd/internal/obj/x86/asm6.go
+++ b/src/cmd/internal/obj/x86/asm6.go
@@ -2551,22 +2551,6 @@ func prefixof(ctxt *obj.Link, a *obj.Addr) int {
}
}
- if ctxt.Arch.Family == sys.I386 {
- if a.Index == REG_TLS && ctxt.Flag_shared {
- // When building for inclusion into a shared library, an instruction of the form
- // MOVL off(CX)(TLS*1), AX
- // becomes
- // mov %gs:off(%ecx), %eax
- // which assumes that the correct TLS offset has been loaded into %ecx (today
- // there is only one TLS variable -- g -- so this is OK). When not building for
- // a shared library the instruction it becomes
- // mov 0x0(%ecx), %eax
- // and a R_TLS_LE relocation, and so does not require a prefix.
- return 0x65 // GS
- }
- return 0
- }
-
switch a.Index {
case REG_CS:
return 0x2e
@@ -2582,11 +2566,18 @@ func prefixof(ctxt *obj.Link, a *obj.Addr) int {
// When building for inclusion into a shared library, an instruction of the form
// MOV off(CX)(TLS*1), AX
// becomes
- // mov %fs:off(%rcx), %rax
- // which assumes that the correct TLS offset has been loaded into %rcx (today
+ // mov %gs:off(%ecx), %eax // on i386
+ // mov %fs:off(%rcx), %rax // on amd64
+ // which assumes that the correct TLS offset has been loaded into CX (today
// there is only one TLS variable -- g -- so this is OK). When not building for
- // a shared library the instruction does not require a prefix.
- return 0x64
+ // a shared library the instruction it becomes
+ // mov 0x0(%ecx), %eax // on i386
+ // mov 0x0(%rcx), %rax // on amd64
+ // and a R_TLS_LE relocation, and so does not require a prefix.
+ if ctxt.Arch.Family == sys.I386 {
+ return 0x65 // GS
+ }
+ return 0x64 // FS
}
case REG_FS:
@@ -3725,7 +3716,7 @@ func (ab *AsmBuf) asmandsz(ctxt *obj.Link, cursym *obj.LSym, p *obj.Prog, a *obj
if REG_AX <= base && base <= REG_R15 {
if a.Index == REG_TLS && !ctxt.Flag_shared && !isAndroid &&
- !(ctxt.Headtype == objabi.Hwindows && ctxt.Arch.Family == sys.AMD64) {
+ ctxt.Headtype != objabi.Hwindows {
rel = obj.Reloc{}
rel.Type = objabi.R_TLS_LE
rel.Siz = 4
@@ -5137,19 +5128,6 @@ func (ab *AsmBuf) doasm(ctxt *obj.Link, cursym *obj.LSym, p *obj.Prog) {
pp.From.Index = REG_NONE
ab.Put1(0x8B)
ab.asmand(ctxt, cursym, p, &pp.From, &p.To)
-
- case objabi.Hwindows:
- // Windows TLS base is always 0x14(FS).
- pp.From = p.From
-
- pp.From.Type = obj.TYPE_MEM
- pp.From.Reg = REG_FS
- pp.From.Offset = 0x14
- pp.From.Index = REG_NONE
- pp.From.Scale = 0
- ab.Put2(0x64, // FS
- 0x8B)
- ab.asmand(ctxt, cursym, p, &pp.From, &p.To)
}
break
}
diff --git a/src/cmd/internal/obj/x86/obj6.go b/src/cmd/internal/obj/x86/obj6.go
index 85a4260453..a071762681 100644
--- a/src/cmd/internal/obj/x86/obj6.go
+++ b/src/cmd/internal/obj/x86/obj6.go
@@ -158,11 +158,11 @@ func progedit(ctxt *obj.Link, p *obj.Prog, newprog obj.ProgAlloc) {
}
}
- // Android and Win64 use a tls offset determined at runtime. Rewrite
+ // Android and Windows use a tls offset determined at runtime. Rewrite
// MOVQ TLS, BX
// to
// MOVQ runtime.tls_g(SB), BX
- if (isAndroid || (ctxt.Headtype == objabi.Hwindows && ctxt.Arch.Family == sys.AMD64)) &&
+ if (isAndroid || ctxt.Headtype == objabi.Hwindows) &&
(p.As == AMOVQ || p.As == AMOVL) && p.From.Type == obj.TYPE_REG && p.From.Reg == REG_TLS && p.To.Type == obj.TYPE_REG && REG_AX <= p.To.Reg && p.To.Reg <= REG_R15 {
p.From.Type = obj.TYPE_MEM
p.From.Name = obj.NAME_EXTERN
@@ -170,17 +170,23 @@ func progedit(ctxt *obj.Link, p *obj.Prog, newprog obj.ProgAlloc) {
p.From.Sym = ctxt.Lookup("runtime.tls_g")
p.From.Index = REG_NONE
if ctxt.Headtype == objabi.Hwindows {
- // Win64 requires an additional indirection
+ // Windows requires an additional indirection
// to retrieve the TLS pointer,
- // as runtime.tls_g contains the TLS offset from GS.
- // add
+ // as runtime.tls_g contains the TLS offset from GS or FS.
+ // on AMD64 add
// MOVQ 0(BX)(GS*1), BX
+ // on 386 add
+ // MOVQ 0(BX)(FS*1), BX4
q := obj.Appendp(p, newprog)
q.As = p.As
q.From = obj.Addr{}
q.From.Type = obj.TYPE_MEM
q.From.Reg = p.To.Reg
- q.From.Index = REG_GS
+ if ctxt.Arch.Family == sys.AMD64 {
+ q.From.Index = REG_GS
+ } else {
+ q.From.Index = REG_FS
+ }
q.From.Scale = 1
q.From.Offset = 0
q.To = p.To
diff --git a/src/runtime/asm_386.s b/src/runtime/asm_386.s
index e16880c950..02179d2ee9 100644
--- a/src/runtime/asm_386.s
+++ b/src/runtime/asm_386.s
@@ -171,8 +171,12 @@ nocpuinfo:
MOVL $runtime·tls_g(SB), 8(SP) // arg 3: &tls_g
#else
MOVL $0, BX
- MOVL BX, 12(SP) // arg 3,4: not used when using platform's TLS
- MOVL BX, 8(SP)
+ MOVL BX, 12(SP) // arg 4: not used when using platform's TLS
+#ifdef GOOS_windows
+ MOVL $runtime·tls_g(SB), 8(SP) // arg 3: &tls_g
+#else
+ MOVL BX, 8(SP) // arg 3: not used when using platform's TLS
+#endif
#endif
MOVL $setg_gcc<>(SB), BX
MOVL BX, 4(SP) // arg 2: setg_gcc
@@ -795,14 +799,15 @@ havem:
TEXT runtime·setg(SB), NOSPLIT, $0-4
MOVL gg+0(FP), BX
#ifdef GOOS_windows
+ MOVL runtime·tls_g(SB), CX
CMPL BX, $0
JNE settls
- MOVL $0, 0x14(FS)
+ MOVL $0, 0(CX)(FS)
RET
settls:
MOVL g_m(BX), AX
LEAL m_tls(AX), AX
- MOVL AX, 0x14(FS)
+ MOVL AX, 0(CX)(FS)
#endif
get_tls(CX)
MOVL BX, g(CX)
@@ -867,6 +872,9 @@ rdtsc:
JMP done
TEXT ldt0setup<>(SB),NOSPLIT,$16-0
+#ifdef GOOS_windows
+ CALL runtime·wintls(SB)
+#endif
// set up ldt 7 to point at m0.tls
// ldt 1 would be fine on Linux, but on OS X, 7 is as low as we can go.
// the entry number is just a hint. setldt will set up GS with what it used.
@@ -1577,3 +1585,6 @@ TEXT runtime·panicExtendSlice3CU(SB),NOSPLIT,$0-12
DATA runtime·tls_g+0(SB)/4, $8
GLOBL runtime·tls_g+0(SB), NOPTR, $4
#endif
+#ifdef GOOS_windows
+GLOBL runtime·tls_g+0(SB), NOPTR, $4
+#endif
diff --git a/src/runtime/cgo/gcc_windows_386.c b/src/runtime/cgo/gcc_windows_386.c
index 56fbaac9b8..0f4f01c7c0 100644
--- a/src/runtime/cgo/gcc_windows_386.c
+++ b/src/runtime/cgo/gcc_windows_386.c
@@ -12,10 +12,12 @@
#include "libcgo_windows.h"
static void threadentry(void*);
+static DWORD *tls_g;
void
-x_cgo_init(G *g)
+x_cgo_init(G *g, void (*setg)(void*), void **tlsg, void **tlsbase)
{
+ tls_g = (DWORD *)tlsg;
}
@@ -39,10 +41,10 @@ threadentry(void *v)
* Set specific keys in thread local storage.
*/
asm volatile (
- "movl %0, %%fs:0x14\n" // MOVL tls0, 0x14(FS)
- "movl %%fs:0x14, %%eax\n" // MOVL 0x14(FS), tmp
- "movl %1, 0(%%eax)\n" // MOVL g, 0(FS)
- :: "r"(ts.tls), "r"(ts.g) : "%eax"
+ "movl %0, %%fs:0(%1)\n" // MOVL tls0, 0(tls_g)(FS)
+ "movl %%fs:0(%1), %%eax\n" // MOVL 0(tls_g)(FS), tmp
+ "movl %2, 0(%%eax)\n" // MOVL g, 0(AX)
+ :: "r"(ts.tls), "r"(*tls_g), "r"(ts.g) : "%eax"
);
crosscall_386(ts.fn);
diff --git a/src/runtime/sys_windows_386.s b/src/runtime/sys_windows_386.s
index cf3a439523..8713f7d0d9 100644
--- a/src/runtime/sys_windows_386.s
+++ b/src/runtime/sys_windows_386.s
@@ -7,6 +7,9 @@
#include "textflag.h"
#include "time_windows.h"
+// Offsets into Thread Environment Block (pointer in FS)
+#define TEB_TlsSlots 0xE10
+
// void runtime·asmstdcall(void *c);
TEXT runtime·asmstdcall(SB),NOSPLIT,$0
MOVL fn+0(FP), BX
@@ -222,7 +225,7 @@ TEXT runtime·callbackasm1(SB),NOSPLIT,$0
RET
// void tstart(M *newm);
-TEXT tstart<>(SB),NOSPLIT,$0
+TEXT tstart<>(SB),NOSPLIT,$8-4
MOVL newm+0(FP), CX // m
MOVL m_g0(CX), DX // g
@@ -236,10 +239,11 @@ TEXT tstart<>(SB),NOSPLIT,$0
MOVL AX, g_stackguard1(DX)
// Set up tls.
- LEAL m_tls(CX), SI
- MOVL SI, 0x14(FS)
+ LEAL m_tls(CX), DI
MOVL CX, g_m(DX)
- MOVL DX, g(SI)
+ MOVL DX, g(DI)
+ MOVL DI, 4(SP)
+ CALL runtime·setldt(SB) // clobbers CX and DX
// Someday the convention will be D is always cleared.
CLD
@@ -266,10 +270,11 @@ TEXT runtime·tstart_stdcall(SB),NOSPLIT,$0
RET
-// setldt(int entry, int address, int limit)
-TEXT runtime·setldt(SB),NOSPLIT,$0
- MOVL base+4(FP), CX
- MOVL CX, 0x14(FS)
+// setldt(int slot, int base, int size)
+TEXT runtime·setldt(SB),NOSPLIT,$0-12
+ MOVL base+4(FP), DX
+ MOVL runtime·tls_g(SB), CX
+ MOVL DX, 0(CX)(FS)
RET
// Runs on OS stack.
@@ -356,3 +361,28 @@ loop:
useQPC:
JMP runtime·nanotimeQPC(SB)
RET
+
+// This is called from rt0_go, which runs on the system stack
+// using the initial stack allocated by the OS.
+TEXT runtime·wintls(SB),NOSPLIT|NOFRAME,$0
+ // Allocate a TLS slot to hold g across calls to external code
+ MOVL SP, BP
+ MOVL runtime·_TlsAlloc(SB), AX
+ CALL AX
+ MOVL BP, SP
+
+ MOVL AX, CX // TLS index
+
+ // Assert that slot is less than 64 so we can use _TEB->TlsSlots
+ CMPL CX, $64
+ JB ok
+ CALL runtime·abort(SB)
+ok:
+ // Convert the TLS index at CX into
+ // an offset from TEB_TlsSlots.
+ SHLL $2, CX
+
+ // Save offset from TLS into tls_g.
+ ADDL $TEB_TlsSlots, CX
+ MOVL CX, runtime·tls_g(SB)
+ RET
generated by cgit v1.3 (git 2.53.0) at 2026-04-15 05:06:07 +0000