1
0
mirror of https://github.com/golang/go synced 2024-11-19 05:34:40 -07:00

cmd/internal/obj/x86: implement -shared computation of TLS base

Somehow, terribly embarrassingly, I lost part of the "re-enable
-shared on amd64" patch when rebasing before it got submitted.
This restores it and also fixes the addend to be the necessary -4.

Change-Id: If71a09121d911a863bc07f1828ef76e3a54c1074
Reviewed-on: https://go-review.googlesource.com/6802
Reviewed-by: Russ Cox <rsc@golang.org>
Run-TryBot: Minux Ma <minux@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
This commit is contained in:
Michael Hudson-Doyle 2015-03-05 14:21:42 +13:00 committed by Minux Ma
parent bcf43e9565
commit e73981512f

View File

@ -3765,6 +3765,39 @@ func doasm(ctxt *obj.Link, p *obj.Prog) {
ctxt.Andptr = ctxt.Andptr[1:] ctxt.Andptr = ctxt.Andptr[1:]
asmand(ctxt, p, &pp.From, &p.To) asmand(ctxt, p, &pp.From, &p.To)
case obj.Hlinux:
if ctxt.Flag_shared == 0 {
log.Fatalf("unknown TLS base location for linux without -shared")
}
// Note that this is not generating the same insn as the other cases.
// MOV TLS, R_to
// becomes
// movq g@gottpoff(%rip), R_to
// which is encoded as
// movq 0(%rip), R_to
// and a R_TLS_IE reloc. This all assumes the only tls variable we access
// is g, which we can't check here, but will when we assemble the second
// instruction.
ctxt.Rexflag = Pw | (regrex[p.To.Reg] & Rxr)
ctxt.Andptr[0] = 0x8B
ctxt.Andptr = ctxt.Andptr[1:]
ctxt.Andptr[0] = byte(0x05 | (reg[p.To.Reg] << 3))
ctxt.Andptr = ctxt.Andptr[1:]
r = obj.Addrel(ctxt.Cursym)
r.Off = int32(p.Pc + int64(-cap(ctxt.Andptr)+cap(ctxt.And[:])))
r.Type = obj.R_TLS_IE
r.Siz = 4
r.Add = -4
ctxt.Andptr[0] = 0x00
ctxt.Andptr = ctxt.Andptr[1:]
ctxt.Andptr[0] = 0x00
ctxt.Andptr = ctxt.Andptr[1:]
ctxt.Andptr[0] = 0x00
ctxt.Andptr = ctxt.Andptr[1:]
ctxt.Andptr[0] = 0x00
ctxt.Andptr = ctxt.Andptr[1:]
case obj.Hplan9: case obj.Hplan9:
if ctxt.Plan9privates == nil { if ctxt.Plan9privates == nil {
ctxt.Plan9privates = obj.Linklookup(ctxt, "_privates", 0) ctxt.Plan9privates = obj.Linklookup(ctxt, "_privates", 0)