From 8981092d71aee273d27b0e11cf932a34d4d365c1 Mon Sep 17 00:00:00 2001 From: "Jason A. Donenfeld" Date: Sun, 8 Nov 2020 03:20:36 +0100 Subject: [PATCH] cmd/link: ignore SEH marking on PE objects Microsoft's linker looks at whether all input objects have an empty section called @feat.00. If all of them do, then it enables SEH; otherwise it doesn't enable that feature. So, since around the Windows XP SP2 era, most tools that make PE objects just tack on that section, so that it won't gimp Microsoft's linker logic. Go doesn't support SEH, so in theory, none of this really matters to us. But actually, if the linker tries to ingest an object with @feat.00 -- which are produced by LLVM's resource compiler, for example -- it chokes because of the IMAGE_SYM_ABSOLUTE section that it doesn't know how to deal with. Since @feat.00 is just a marking anyway, skip IMAGE_SYM_ABSOLUTE sections that are called @feat.00. Change-Id: I1d7bfcf6001186c53e2c487c5ac251ca65efefee Reviewed-on: https://go-review.googlesource.com/c/go/+/268239 Run-TryBot: Jason A. Donenfeld TryBot-Result: Go Bot Reviewed-by: Cherry Zhang Trust: Alex Brainman Trust: Jason A. Donenfeld --- src/cmd/link/internal/loadpe/ldpe.go | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/src/cmd/link/internal/loadpe/ldpe.go b/src/cmd/link/internal/loadpe/ldpe.go index c72965dddc..1e6f978531 100644 --- a/src/cmd/link/internal/loadpe/ldpe.go +++ b/src/cmd/link/internal/loadpe/ldpe.go @@ -6,6 +6,7 @@ package loadpe import ( + "bytes" "cmd/internal/bio" "cmd/internal/objabi" "cmd/internal/sys" @@ -359,6 +360,20 @@ func Load(l *loader.Loader, arch *sys.Arch, localSymVersion int, input *bio.Read if pesym.SectionNumber == IMAGE_SYM_DEBUG { continue } + if pesym.SectionNumber == IMAGE_SYM_ABSOLUTE && bytes.Equal(pesym.Name[:], []byte("@feat.00")) { + // Microsoft's linker looks at whether all input objects have an empty + // section called @feat.00. If all of them do, then it enables SEH; + // otherwise it doesn't enable that feature. So, since around the Windows + // XP SP2 era, most tools that make PE objects just tack on that section, + // so that it won't gimp Microsoft's linker logic. Go doesn't support SEH, + // so in theory, none of this really matters to us. But actually, if the + // linker tries to ingest an object with @feat.00 -- which are produced by + // LLVM's resource compiler, for example -- it chokes because of the + // IMAGE_SYM_ABSOLUTE section that it doesn't know how to deal with. Since + // @feat.00 is just a marking anyway, skip IMAGE_SYM_ABSOLUTE sections that + // are called @feat.00. + continue + } var sect *pe.Section if pesym.SectionNumber > 0 { sect = f.Sections[pesym.SectionNumber-1] -- 2.48.1