Read fips scope marker addresses using adrp instead of adr to increas…

…e reach (#1332)

When including the new Ed25519 implementations in the FIPS build the follow error occurred:
bcm.c:47662: Error: pc-relative address offset out of range
The reason is that we get the address of e.g. BORINGSSL_bcm_text_end using adr like this:
adr x4, BORINGSSL_bcm_text_end
But since the size of the fips module has slowly increased the last few years the amount of memory we attempt to jump with adr runs over the reach of the instruction (about 1MB or so).

The solution is to no longer consider BORINGSSL_bcm_text_[end,start] for special and use a redirector function to resolve their addresses.

util/fipstools/delocate/delocate.go

@@ -407,7 +407,7 @@ func (d *delocation) loadAarch64Address(statement *node32, targetReg string, sym
 
 	_, isKnown := d.symbols[symbol]
 	isLocal := strings.HasPrefix(symbol, ".L")
-	if isKnown || isLocal || isSynthesized(symbol) {
+	if isKnown || isLocal || isSynthesized(symbol, aarch64) {
 		if isLocal {
 			symbol = d.mapLocalSymbol(symbol)
 		} else if isKnown {
@@ -566,10 +566,17 @@ func (d *delocation) processAarch64Instruction(statement, instruction *node32) (
 				symbol, offset, _, didChange, symbolIsLocal, _ := d.parseMemRef(arg.up)
 				changed = didChange
 
-				if _, knownSymbol := d.symbols[symbol]; knownSymbol {
+				if isFipsScopeMarkers(symbol) {
+					// fips scope markers are known. But they challenge the adr
+					// reach, so go through GOT via an adrp outside the scope.
+					redirector := redirectorName(symbol)
+					d.redirectors[symbol] = redirector
+					symbol = redirector
+					changed = true
+				} else if _, knownSymbol := d.symbols[symbol]; knownSymbol {
 					symbol = localTargetName(symbol)
 					changed = true
-				} else if !symbolIsLocal && !isSynthesized(symbol) {
+				} else if !symbolIsLocal && !isSynthesized(symbol, aarch64) {
 					redirector := redirectorName(symbol)
 					d.redirectors[symbol] = redirector
 					symbol = redirector
@@ -981,7 +988,7 @@ Args:
 				} else if _, knownSymbol := d.symbols[symbol]; knownSymbol {
 					symbol = localTargetName(symbol)
 					changed = true
-				} else if !symbolIsLocal && !isSynthesized(symbol) && len(section) == 0 {
+				} else if !symbolIsLocal && !isSynthesized(symbol, ppc64le) && len(section) == 0 {
 					changed = true
 					d.redirectors[symbol] = redirectorName(symbol)
 					symbol = redirectorName(symbol)
@@ -1421,7 +1428,7 @@ Args:
 				if _, knownSymbol := d.symbols[symbol]; knownSymbol {
 					symbol = localTargetName(symbol)
 					changed = true
-				} else if !symbolIsLocal && !isSynthesized(symbol) {
+				} else if !symbolIsLocal && !isSynthesized(symbol, x86_64) {
 					// Unknown symbol via PLT is an
 					// out-call from the module, e.g.
 					// memcpy.
@@ -1443,7 +1450,7 @@ Args:
 				if _, knownSymbol := d.symbols[symbol]; knownSymbol {
 					symbol = localTargetName(symbol)
 					changed = true
-				} else if !isSynthesized(symbol) {
+				} else if !isSynthesized(symbol, x86_64) {
 					useGOT = true
 				}
 
@@ -1834,6 +1841,13 @@ func transform(w stringWriter, inputs []inputFile) error {
 	}
 	w.WriteString(fmt.Sprintf(".file %d \"inserted_by_delocate.c\"%s\n", maxObservedFileNumber+1, fileTrailing))
 	w.WriteString(fmt.Sprintf(".loc %d 1 0\n", maxObservedFileNumber+1))
+	if d.processor == aarch64 {
+		// Grab the address of BORINGSSL_bcm_test_[start,end] via a relocation
+		// from a redirector function. For this to work, need to add the markers
+		// to the symbol table.
+		w.WriteString(fmt.Sprintf(".global BORINGSSL_bcm_text_start\n"))
+		w.WriteString(fmt.Sprintf(".type BORINGSSL_bcm_text_start, @function\n"))
+	}
 	w.WriteString("BORINGSSL_bcm_text_start:\n")
 
 	for _, input := range inputs {
@@ -1844,6 +1858,10 @@ func transform(w stringWriter, inputs []inputFile) error {
 
 	w.WriteString(".text\n")
 	w.WriteString(fmt.Sprintf(".loc %d 2 0\n", maxObservedFileNumber+1))
+	if d.processor == aarch64 {
+		w.WriteString(fmt.Sprintf(".global BORINGSSL_bcm_text_end\n"))
+		w.WriteString(fmt.Sprintf(".type BORINGSSL_bcm_text_end, @function\n"))
+	}
 	w.WriteString("BORINGSSL_bcm_text_end:\n")
 
 	// Emit redirector functions. Each is a single jump instruction.
@@ -2256,10 +2274,23 @@ func localEntryName(name string) string {
 	return ".L" + name + "_local_entry"
 }
 
-func isSynthesized(symbol string) bool {
-	return strings.HasSuffix(symbol, "_bss_get") ||
+func isSynthesized(symbol string, processor processorType) bool {
+	SymbolisSynthesized := strings.HasSuffix(symbol, "_bss_get") ||
 		symbol == "OPENSSL_ia32cap_get" ||
-		strings.HasPrefix(symbol, "BORINGSSL_bcm_text_")
+		symbol == "BORINGSSL_bcm_text_hash"
+
+	// While BORINGSSL_bcm_text_[start,end] are known symbols, on aarch64 we go
+	// through the GOT because adr doesn't have adequate reach.
+	if (processor != aarch64) {
+		SymbolisSynthesized = SymbolisSynthesized || strings.HasPrefix(symbol, "BORINGSSL_bcm_text_")
+	}
+
+	return SymbolisSynthesized
+}
+
+func isFipsScopeMarkers(symbol string) bool {
+	return	symbol == "BORINGSSL_bcm_text_start" ||
+		symbol == "BORINGSSL_bcm_text_end"
 }
 
 func redirectorName(symbol string) string {

util/fipstools/delocate/testdata/aarch64-Basic/in.s

@@ -87,6 +87,10 @@ foo:
 	add x22, sp, #(13*32)+96
 	add x22, sp, #(13*32)+96*32
 
+	// Ensure BORINGSSL_bcm_text_[end,start] are loaded through GOT
+	adrp x4, :got:BORINGSSL_bcm_text_start
+	adrp x5, :got:BORINGSSL_bcm_text_end
+
 local_function:
 
 // BSS data

util/fipstools/delocate/testdata/aarch64-Basic/out.s

@@ -1,6 +1,8 @@
 .text
 .file 1 "inserted_by_delocate.c"
 .loc 1 1 0
+.global BORINGSSL_bcm_text_start
+.type BORINGSSL_bcm_text_start, @function
 BORINGSSL_bcm_text_start:
 	.type foo, %function
 	.globl foo
@@ -141,6 +143,22 @@ foo:
 	add x22, sp, #(13*32)+96
 	add x22, sp, #(13*32)+96*32
 
+	// Ensure BORINGSSL_bcm_text_[end,start] are loaded through GOT
+// WAS adrp x4, :got:BORINGSSL_bcm_text_start
+	sub sp, sp, 128
+	stp x0, lr, [sp, #-16]!
+	bl .Lboringssl_loadgot_BORINGSSL_bcm_text_start
+	mov x4, x0
+	ldp x0, lr, [sp], #16
+	add sp, sp, 128
+// WAS adrp x5, :got:BORINGSSL_bcm_text_end
+	sub sp, sp, 128
+	stp x0, lr, [sp, #-16]!
+	bl .Lboringssl_loadgot_BORINGSSL_bcm_text_end
+	mov x5, x0
+	ldp x0, lr, [sp], #16
+	add sp, sp, 128
+
 .Llocal_function_local_target:
 local_function:
 
@@ -154,6 +172,8 @@ bss_symbol:
 .size bss_symbol, 4
 .text
 .loc 1 2 0
+.global BORINGSSL_bcm_text_end
+.type BORINGSSL_bcm_text_end, @function
 BORINGSSL_bcm_text_end:
 .p2align 2
 .hidden bcm_redirector_remote_function
@@ -190,6 +210,26 @@ bss_symbol_bss_get:
 .cfi_endproc
 .size bss_symbol_bss_get, .-bss_symbol_bss_get
 .p2align 2
+.hidden .Lboringssl_loadgot_BORINGSSL_bcm_text_end
+.type .Lboringssl_loadgot_BORINGSSL_bcm_text_end, @function
+.Lboringssl_loadgot_BORINGSSL_bcm_text_end:
+.cfi_startproc
+	adrp x0, :got:BORINGSSL_bcm_text_end
+	ldr x0, [x0, :got_lo12:BORINGSSL_bcm_text_end]
+	ret
+.cfi_endproc
+.size .Lboringssl_loadgot_BORINGSSL_bcm_text_end, .-.Lboringssl_loadgot_BORINGSSL_bcm_text_end
+.p2align 2
+.hidden .Lboringssl_loadgot_BORINGSSL_bcm_text_start
+.type .Lboringssl_loadgot_BORINGSSL_bcm_text_start, @function
+.Lboringssl_loadgot_BORINGSSL_bcm_text_start:
+.cfi_startproc
+	adrp x0, :got:BORINGSSL_bcm_text_start
+	ldr x0, [x0, :got_lo12:BORINGSSL_bcm_text_start]
+	ret
+.cfi_endproc
+.size .Lboringssl_loadgot_BORINGSSL_bcm_text_start, .-.Lboringssl_loadgot_BORINGSSL_bcm_text_start
+.p2align 2
 .hidden .Lboringssl_loadgot_stderr
 .type .Lboringssl_loadgot_stderr, @function
 .Lboringssl_loadgot_stderr: