cmd/link: mark holes in functab with end PC-1
When we have multiple text sections, we need to mark holes between
the sections in the functab. A hole is marked with an entry with
the end PC of the previous section. As we now use offsets instead
of (relocated) PCs, the end offset of a section may be the same of
the start of the next one. Distinguish it by using the end address
-1.
For #48837.
Change-Id: I121aac53b32a869378632cf151cb1b6f98ad3089
Reviewed-on: https://go-review.googlesource.com/c/go/+/354636
Trust: Cherry Mui <cherryyz@google.com>
Trust: Josh Bleecher Snyder <josharian@gmail.com>
Run-TryBot: Cherry Mui <cherryyz@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
diff --git a/src/cmd/link/internal/ld/pcln.go b/src/cmd/link/internal/ld/pcln.go
index ee26ee2..465c52b 100644
--- a/src/cmd/link/internal/ld/pcln.go
+++ b/src/cmd/link/internal/ld/pcln.go
@@ -631,9 +631,11 @@
if thisSect := ldr.SymSect(s); thisSect != prevSect {
// With multiple text sections, there may be a hole here in the
// address space. We use an invalid funcoff value to mark the hole.
+ // Use the end PC - 1 to distinguish the end of a section vs. the
+ // start of the next.
// See also runtime/symtab.go:findfunc
prevFuncSize := uint32(ldr.SymSize(prevFunc))
- sb.SetUint32(ctxt.Arch, int64(funcIndex*2*4), pcOff(prevFunc)+prevFuncSize)
+ sb.SetUint32(ctxt.Arch, int64(funcIndex*2*4), pcOff(prevFunc)+prevFuncSize-1)
sb.SetUint32(ctxt.Arch, int64((funcIndex*2+1)*4), ^uint32(0))
funcIndex++
prevSect = thisSect
