diff --git a/src/cmd/ld/macho.c b/src/cmd/ld/macho.c index 05638f7254..6781c25a43 100644 --- a/src/cmd/ld/macho.c +++ b/src/cmd/ld/macho.c @@ -499,7 +499,24 @@ domacholink(void) s3 = lookup(".linkedit.got", 0); s4 = lookup(".dynstr", 0); - while(s4->size%4) + // Force the linkedit section to end on a 16-byte + // boundary. This allows pure (non-cgo) Go binaries + // to be code signed correctly. + // + // Apple's codesign_allocate (a helper utility for + // the codesign utility) can do this fine itself if + // it is run on a dynamic Mach-O binary. However, + // when it is run on a pure (non-cgo) Go binary, where + // the linkedit section is mostly empty, it fails to + // account for the extra padding that it itself adds + // when adding the LC_CODE_SIGNATURE load command + // (which must be aligned on a 16-byte boundary). + // + // By forcing the linkedit section to end on a 16-byte + // boundary, codesign_allocate will not need to apply + // any alignment padding itself, working around the + // issue. + while(s4->size%16) adduint8(s4, 0); size = s1->size + s2->size + s3->size + s4->size;