cmd/link: set runtime.text to the address of the first function

In CL 240065 we changed it to set to FlagTextAddr. Normally it
is the address of the first function, except on plan9/amd64
where, as FlagTextAddr is not aligned, it is rounded up. Set it
to the actual text start address.

Fixes #41137.

Change-Id: I1bba67f5eb4e24d9f745a11350fc999ff48bff45
Reviewed-on: https://go-review.googlesource.com/c/go/+/261644
Trust: Cherry Zhang <cherryyz@google.com>
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: David du Colombier <0intro@gmail.com>
Reviewed-by: Than McIntosh <thanm@google.com>

diff --git a/src/cmd/link/internal/ld/data.go b/src/cmd/link/internal/ld/data.go
index 3cd7b4ad0b45ad99c093159254a8f4f50ac034de..84e03a4011396f4eb220d8b7d3ff71f297ff3418 100644 (file)
--- a/src/cmd/link/internal/ld/data.go
+++ b/src/cmd/link/internal/ld/data.go
@@ -2188,7 +2188,7 @@ func (ctxt *Link) textaddress() {
                ctxt.Textp[0] = text
        }
 
-       va := uint64(*FlagTextAddr)
+       va := uint64(Rnd(*FlagTextAddr, int64(Funcalign)))
        n := 1
        sect.Vaddr = va
        ntramps := 0
@@ -2214,7 +2214,7 @@ func (ctxt *Link) textaddress() {
                // Set the address of the start/end symbols, if not already
                // (i.e. not darwin+dynlink or AIX+external, see above).
                ldr.SetSymValue(etext, int64(va))
-               ldr.SetSymValue(text, *FlagTextAddr)
+               ldr.SetSymValue(text, int64(Segtext.Sections[0].Vaddr))
        }
 
        // merge tramps into Textp, keeping Textp in address order