Update delocate to handle new compiler output.
Delocate failed with some versions of Clang that reference
OPENSSL_ia32cap_P with an orq instruction.
Change-Id: I448d291594f5f147424e6f7014a681c4201b0aee
Reviewed-on: https://boringssl-review.googlesource.com/29764
Reviewed-by: Adam Langley <alangley@gmail.com>
diff --git a/util/fipstools/delocate.go b/util/fipstools/delocate.go
index 827e446..d58e5be 100644
--- a/util/fipstools/delocate.go
+++ b/util/fipstools/delocate.go
@@ -795,6 +795,9 @@
instrTransformingMove
instrJump
instrConditionalMove
+ // instrCombine merges the source and destination in some fashion, for example
+ // a 2-operand bitwise operation.
+ instrCombine
instrOther
)
@@ -820,6 +823,11 @@
return instrJump
}
+ case "orq", "andq", "xorq":
+ if len(args) == 2 {
+ return instrCombine
+ }
+
case "vpbroadcastq":
if len(args) == 2 {
return instrTransformingMove
@@ -855,24 +863,41 @@
}
}
-func saveRegister(w stringWriter) wrapperFunc {
+func saveFlags(w stringWriter, redzoneCleared bool) wrapperFunc {
return func(k func()) {
- w.WriteString("\tleaq -128(%rsp), %rsp\n") // Clear the red zone.
- w.WriteString("\tpushq %rax\n")
+ if !redzoneCleared {
+ w.WriteString("\tleaq -128(%rsp), %rsp\n") // Clear the red zone.
+ defer w.WriteString("\tleaq 128(%rsp), %rsp\n")
+ }
+ w.WriteString("\tpushfq\n")
k()
- w.WriteString("\tpopq %rax\n")
- w.WriteString("\tleaq 128(%rsp), %rsp\n")
+ w.WriteString("\tpopfq\n")
}
}
-func moveTo(w stringWriter, target string, isAVX bool) wrapperFunc {
+func saveRegister(w stringWriter, avoidReg string) (wrapperFunc, string) {
+ reg := "%rax"
+ if reg == avoidReg {
+ reg = "%rbx"
+ }
+
+ return func(k func()) {
+ w.WriteString("\tleaq -128(%rsp), %rsp\n") // Clear the red zone.
+ w.WriteString("\tpushq " + reg + "\n")
+ k()
+ w.WriteString("\tpopq " + reg + "\n")
+ w.WriteString("\tleaq 128(%rsp), %rsp\n")
+ }, reg
+}
+
+func moveTo(w stringWriter, target string, isAVX bool, source string) wrapperFunc {
return func(k func()) {
k()
prefix := ""
if isAVX {
prefix = "v"
}
- w.WriteString("\t" + prefix + "movq %rax, " + target + "\n")
+ w.WriteString("\t" + prefix + "movq " + source + ", " + target + "\n")
}
}
@@ -883,6 +908,13 @@
}
}
+func combineOp(w stringWriter, instructionName, source, dest string) wrapperFunc {
+ return func(k func()) {
+ k()
+ w.WriteString("\t" + instructionName + " " + source + ", " + dest + "\n")
+ }
+}
+
func isValidLEATarget(reg string) bool {
return !strings.HasPrefix(reg, "%xmm") && !strings.HasPrefix(reg, "%ymm") && !strings.HasPrefix(reg, "%zmm")
}
@@ -938,16 +970,9 @@
symbol, offset, section, didChange, symbolIsLocal, memRef := d.parseMemRef(arg.up)
changed = didChange
- if symbol == "OPENSSL_ia32cap_P" {
- var ok bool
- if section == "GOTPCREL" {
- ok = instructionName == "movq"
- } else if section == "" {
- ok = instructionName == "leaq"
- }
-
- if !ok {
- return nil, fmt.Errorf("instruction %q referenced OPENSSL_ia32cap_P in section %q, should be a movq from GOTPCREL or a direct leaq", instructionName, section)
+ if symbol == "OPENSSL_ia32cap_P" && section == "" {
+ if instructionName != "leaq" {
+ return nil, fmt.Errorf("non-leaq instruction %q referenced OPENSSL_ia32cap_P directly", instructionName)
}
if i != 0 || len(argNodes) != 2 || !d.isRIPRelative(memRef) || len(offset) > 0 {
@@ -963,13 +988,14 @@
}
changed = true
+
+ // Flag-altering instructions (i.e. addq) are going to be used so the
+ // flags need to be preserved.
+ wrappers = append(wrappers, saveFlags(d.output, false /* Red Zone not yet cleared */))
+
wrappers = append(wrappers, func(k func()) {
- d.output.WriteString("\tleaq\t-128(%rsp), %rsp\n") // Clear the red zone.
- d.output.WriteString("\tpushfq\n")
d.output.WriteString("\tleaq\tOPENSSL_ia32cap_addr_delta(%rip), " + reg + "\n")
d.output.WriteString("\taddq\t(" + reg + "), " + reg + "\n")
- d.output.WriteString("\tpopfq\n")
- d.output.WriteString("\tleaq\t128(%rsp), %rsp\n")
})
break Args
@@ -1021,6 +1047,7 @@
// Reduce the instruction to movq symbol@GOTPCREL, targetReg.
var targetReg string
+ var redzoneCleared bool
switch classifyInstruction(instructionName, argNodes) {
case instrPush:
wrappers = append(wrappers, push(d.output))
@@ -1038,23 +1065,45 @@
if isValidLEATarget(targetReg) {
return nil, errors.New("Currently transforming moves are assumed to target XMM registers. Otherwise we'll pop %rax before reading it to do the transform.")
}
+ case instrCombine:
+ targetReg = d.contents(argNodes[1])
+ if !isValidLEATarget(targetReg) {
+ return nil, fmt.Errorf("cannot handle combining instructions targeting non-general registers")
+ }
+ saveRegWrapper, tempReg := saveRegister(d.output, targetReg)
+ redzoneCleared = true
+ wrappers = append(wrappers, saveRegWrapper)
+
+ wrappers = append(wrappers, combineOp(d.output, instructionName, tempReg, targetReg))
+ targetReg = tempReg
default:
return nil, fmt.Errorf("Cannot rewrite GOTPCREL reference for instruction %q", instructionName)
}
- var redzoneCleared bool
if !isValidLEATarget(targetReg) {
// Sometimes the compiler will load from the GOT to an
// XMM register, which is not a valid target of an LEA
// instruction.
- wrappers = append(wrappers, saveRegister(d.output))
+ saveRegWrapper, tempReg := saveRegister(d.output, "")
+ wrappers = append(wrappers, saveRegWrapper)
isAVX := strings.HasPrefix(instructionName, "v")
- wrappers = append(wrappers, moveTo(d.output, targetReg, isAVX))
- targetReg = "%rax"
+ wrappers = append(wrappers, moveTo(d.output, targetReg, isAVX, tempReg))
+ targetReg = tempReg
+ if redzoneCleared {
+ return nil, fmt.Errorf("internal error: Red Zone was already cleared")
+ }
redzoneCleared = true
}
- if useGOT {
+ if symbol == "OPENSSL_ia32cap_P" {
+ // Flag-altering instructions (i.e. addq) are going to be used so the
+ // flags need to be preserved.
+ wrappers = append(wrappers, saveFlags(d.output, redzoneCleared))
+ wrappers = append(wrappers, func(k func()) {
+ d.output.WriteString("\tleaq\tOPENSSL_ia32cap_addr_delta(%rip), " + targetReg + "\n")
+ d.output.WriteString("\taddq\t(" + targetReg + "), " + targetReg + "\n")
+ })
+ } else if useGOT {
wrappers = append(wrappers, d.loadFromGOT(d.output, targetReg, symbol, section, redzoneCleared))
} else {
wrappers = append(wrappers, func(k func()) {
@@ -1239,8 +1288,8 @@
}
w.WriteString(".text\n")
- w.WriteString(fmt.Sprintf(".file %d \"inserted_by_delocate.c\"\n", maxObservedFileNumber + 1))
- w.WriteString(fmt.Sprintf(".loc %d 1 0\n", maxObservedFileNumber + 1))
+ w.WriteString(fmt.Sprintf(".file %d \"inserted_by_delocate.c\"\n", maxObservedFileNumber+1))
+ w.WriteString(fmt.Sprintf(".loc %d 1 0\n", maxObservedFileNumber+1))
w.WriteString("BORINGSSL_bcm_text_start:\n")
for _, input := range inputs {
@@ -1250,7 +1299,7 @@
}
w.WriteString(".text\n")
- w.WriteString(fmt.Sprintf(".loc %d 2 0\n", maxObservedFileNumber + 1))
+ w.WriteString(fmt.Sprintf(".loc %d 2 0\n", maxObservedFileNumber+1))
w.WriteString("BORINGSSL_bcm_text_end:\n")
// Emit redirector functions. Each is a single jump instruction.
