From: Cherry Mui <cherryyz@google.com>
Date: Thu, 7 Oct 2021 20:26:29 +0000 (-0400)
Subject: runtime: handle end PC in textAddr
X-Git-Tag: go1.18beta1~982
X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=6436f5c13d6a5ced6cd5f3873f83ebfae32cce36;p=gostls13.git

runtime: handle end PC in textAddr

As the func table contains the end marker of the text section, we
sometimes need to get that address from an offset. Currently
textAddr doesn't handle that address, as it is not within any
text section. Instead of letting the callers not call textAddr
with the end offset, just handle it more elegantly in textAddr.

For #48837.

Change-Id: I6e97e455f6cb66e9680a7aac6152ba6f4cda2e12
Reviewed-on: https://go-review.googlesource.com/c/go/+/354635
Trust: Cherry Mui <cherryyz@google.com>
Trust: Josh Bleecher Snyder <josharian@gmail.com>
Run-TryBot: Cherry Mui <cherryyz@google.com>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
---

diff --git a/src/runtime/symtab.go b/src/runtime/symtab.go
index 2de518d2e6..e35d8047a1 100644
--- a/src/runtime/symtab.go
+++ b/src/runtime/symtab.go
@@ -623,9 +623,7 @@ func moduledataverify1(datap *moduledata) {
 	}
 
 	min := datap.textAddr(datap.ftab[0].entryoff)
-	// The max PC is outside of the text section.
-	// Subtract 1 to get a PC inside the text section, look it up, then add 1 back in.
-	max := datap.textAddr(datap.ftab[nftab].entryoff-1) + 1
+	max := datap.textAddr(datap.ftab[nftab].entryoff)
 	if datap.minpc != min || datap.maxpc != max {
 		println("minpc=", hex(datap.minpc), "min=", hex(min), "maxpc=", hex(datap.maxpc), "max=", hex(max))
 		throw("minpc or maxpc invalid")
@@ -660,9 +658,10 @@ func (md *moduledata) textAddr(off32 uint32) uintptr {
 	off := uintptr(off32)
 	res := md.text + off
 	if len(md.textsectmap) > 1 {
-		for i := range md.textsectmap {
-			if off >= md.textsectmap[i].vaddr && off < md.textsectmap[i].end {
-				res = md.textsectmap[i].baseaddr + off - md.textsectmap[i].vaddr
+		for i, sect := range md.textsectmap {
+			// For the last section, include the end address (etext), as it is included in the functab.
+			if off >= sect.vaddr && off < sect.end || (i == len(md.textsectmap)-1 && off == sect.end) {
+				res = sect.baseaddr + off - sect.vaddr
 				break
 			}
 		}