golang/ppc64x-overflow-2.patch

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From a5b97a846d70cd8db7f33c24f2b9159f935ce318 Mon Sep 17 00:00:00 2001
From: Lynn Boger <laboger@linux.vnet.ibm.com>
Date: Tue, 13 Sep 2016 15:13:08 -0500
Subject: [PATCH] cmd/compile: large text sections on ppc64le
Additional fixes as submitted upstream.
---
src/cmd/link/internal/ld/data.go | 24 ++++++++++++------------
src/cmd/link/internal/ld/lib.go | 2 +-
src/cmd/link/internal/ld/symtab.go | 2 +-
src/runtime/type.go | 28 ++++++++++++++++++----------
4 files changed, 32 insertions(+), 24 deletions(-)
diff --git a/src/cmd/link/internal/ld/data.go b/src/cmd/link/internal/ld/data.go
index 58ce18c..d8e43ff 100644
--- a/src/cmd/link/internal/ld/data.go
+++ b/src/cmd/link/internal/ld/data.go
@@ -531,7 +531,7 @@ func relocsym(s *LSym) {
// The method offset tables using this relocation expect the offset to be relative
// to the start of the first text section, even if there are multiple.
- if Linkmode == LinkExternal && r.Sym.Sect.Name == ".text" && r.Sym.Sect.Vaddr != Segtext.Vaddr {
+ if r.Sym.Sect.Name == ".text" {
o = Symaddr(r.Sym) - int64(Segtext.Vaddr) + r.Add
} else {
o = Symaddr(r.Sym) - int64(r.Sym.Sect.Vaddr) + r.Add
@@ -1928,7 +1928,6 @@ func textaddress() {
sect.Align = int32(Funcalign)
Linklookup(Ctxt, "runtime.text", 0).Sect = sect
- Linklookup(Ctxt, "runtime.etext", 0).Sect = sect
if HEADTYPE == obj.Hwindows {
Linklookup(Ctxt, ".text", 0).Sect = sect
}
@@ -1964,7 +1963,7 @@ func textaddress() {
// Only break at outermost syms.
- if sym.Outer == nil && Iself && Linkmode == LinkExternal && SysArch.InFamily(sys.PPC64) && va-sect.Vaddr > uint64(0x1c00000) {
+ if sym.Outer == nil && Iself && Linkmode == LinkExternal && SysArch.InFamily(sys.PPC64) && va-sect.Vaddr > 0x1c00000 {
// Set the length for the previous text section
sect.Length = va - sect.Vaddr
@@ -1973,7 +1972,7 @@ func textaddress() {
sect = addsection(&Segtext, ".text", 05)
sect.Vaddr = va
- // Create a symbol for the start and end of the secondary text section
+ // Create a symbol for the start of the secondary text section
Linklookup(Ctxt, fmt.Sprintf("runtime.text.%d", n), 0).Sect = sect
n++
}
@@ -2093,15 +2092,8 @@ func address() {
rodata = Segrodata.Sect
} else {
// Could be multiple .text sections
- n := 1
- for sect := Segtext.Sect.Next; sect != nil; sect = sect.Next {
- if sect.Name != ".text" {
- break
- }
+ for sect := Segtext.Sect.Next; sect != nil && sect.Name == ".text"; sect = sect.Next {
lasttext = sect
- symname := fmt.Sprintf("runtime.text.%d", n)
- xdefine(symname, obj.STEXT, int64(sect.Vaddr))
- n++
}
rodata = lasttext.Next
@@ -2155,6 +2147,14 @@ func address() {
xdefine("runtime.text", obj.STEXT, int64(text.Vaddr))
xdefine("runtime.etext", obj.STEXT, int64(lasttext.Vaddr+lasttext.Length))
+
+ n := 1
+ for sect := Segtext.Sect.Next; sect != nil && sect.Name == ".text"; sect = sect.Next {
+ symname := fmt.Sprintf("runtime.text.%d", n)
+ xdefine(symname, obj.STEXT, int64(sect.Vaddr))
+ n++
+ }
+
if HEADTYPE == obj.Hwindows {
xdefine(".text", obj.STEXT, int64(text.Vaddr))
}
diff --git a/src/cmd/link/internal/ld/lib.go b/src/cmd/link/internal/ld/lib.go
index 709e7ca..c37ef92 100644
--- a/src/cmd/link/internal/ld/lib.go
+++ b/src/cmd/link/internal/ld/lib.go
@@ -1958,7 +1958,7 @@ func genasmsym(put func(*LSym, string, int, int64, int64, int, *LSym)) {
}
n := 0
- // Generate base addresses for all text sections if there are multiple
+ // Generate base addresses for all text sections if there are multiple.
for sect := Segtext.Sect; sect != nil; sect = sect.Next {
if n == 0 {
n++
diff --git a/src/cmd/link/internal/ld/symtab.go b/src/cmd/link/internal/ld/symtab.go
index 80eb33d..ec26f88 100644
--- a/src/cmd/link/internal/ld/symtab.go
+++ b/src/cmd/link/internal/ld/symtab.go
@@ -331,7 +331,7 @@ func textsectionmap() uint32 {
break
}
}
- Symgrow(Ctxt, t, nsections*3*8)
+ Symgrow(Ctxt, t, nsections*(2*int64(SysArch.IntSize)+int64(SysArch.PtrSize)))
off := int64(0)
n := 0
diff --git a/src/runtime/type.go b/src/runtime/type.go
index f641adc..d4df5a9 100644
--- a/src/runtime/type.go
+++ b/src/runtime/type.go
@@ -259,17 +259,25 @@ func (t *_type) textOff(off textOff) unsafe.Pointer {
}
res := uintptr(0)
- // Find the text section range that contains the offset to determine the section's base
- // address. In cases where there are multiple text sections, the base address might be
- // relocated by the linker.
-
- for i := 0; i < len(md.textsectmap); i++ {
- sectaddr := md.textsectmap[i].vaddr
- sectlen := md.textsectmap[i].length
- if uint64(off) >= sectaddr && uint64(off) <= sectaddr+sectlen {
- res = md.textsectmap[i].baseaddr + uintptr(off) - uintptr(md.textsectmap[i].vaddr)
- break
+ // The text, or instruction stream is generated as one large buffer. The off (offset) for a method is
+ // its offset within this buffer. If the total text size gets too large, there can be issues on platforms like ppc64 if
+ // the target of calls are too far for the call instruction. To resolve the large text issue, the text is split
+ // into multiple text sections to allow the linker to generate long calls when necessary. When this happens, the vaddr
+ // for each text section is set to its offset within the text. Each method's offset is compared against the section
+ // vaddrs and sizes to determine the containing section. Then the section relative offset is added to the section's
+ // relocated baseaddr to compute the method addess.
+
+ if len(md.textsectmap) > 1 {
+ for i := 0; i < len(md.textsectmap); i++ {
+ sectaddr := md.textsectmap[i].vaddr
+ sectlen := md.textsectmap[i].length
+ if uint64(off) >= sectaddr && uint64(off) <= sectaddr+sectlen {
+ res = md.textsectmap[i].baseaddr + uintptr(off) - uintptr(md.textsectmap[i].vaddr)
+ break
+ }
}
+ } else {
+ res = md.text + uintptr(off)
}
if res > md.etext {