From ffb07d0c66db2f3f33faedf2927f9aa476d47720 Mon Sep 17 00:00:00 2001 From: Ian Lance Taylor Date: Fri, 24 Feb 2023 15:52:58 -0800 Subject: [PATCH] cmd/link: don't emit PAX_FLAGS segment on Linux We started emitting this segment in 2012 in CL 6326054 for #47. It disabled three kinds of protection: mprotect, randexec, and emutramp. The randexec protection was deprecated some time ago, replaced by PIE. The emutramp and mprotect protection was because we used to rely on being able to create writable executable memory to implement function closures, but that is not true since https://go.dev/s/go11func was implemented. Change-Id: I5e3a5279d76d642b0423d26195b891479a235763 Reviewed-on: https://go-review.googlesource.com/c/go/+/471199 Run-TryBot: Ian Lance Taylor Auto-Submit: Ian Lance Taylor Reviewed-by: Ian Lance Taylor TryBot-Result: Gopher Robot Reviewed-by: Cherry Mui --- src/cmd/link/internal/ld/elf.go | 12 +----------- 1 file changed, 1 insertion(+), 11 deletions(-) diff --git a/src/cmd/link/internal/ld/elf.go b/src/cmd/link/internal/ld/elf.go index 5eeb4a9993..842570d5ef 100644 --- a/src/cmd/link/internal/ld/elf.go +++ b/src/cmd/link/internal/ld/elf.go @@ -2135,25 +2135,15 @@ func asmbElf(ctxt *Link) { } } - if ctxt.HeadType == objabi.Hlinux { + if ctxt.HeadType == objabi.Hlinux || ctxt.HeadType == objabi.Hfreebsd { ph := newElfPhdr() ph.Type = elf.PT_GNU_STACK ph.Flags = elf.PF_W + elf.PF_R ph.Align = uint64(ctxt.Arch.RegSize) - - ph = newElfPhdr() - ph.Type = elf.PT_PAX_FLAGS - ph.Flags = 0x2a00 // mprotect, randexec, emutramp disabled - ph.Align = uint64(ctxt.Arch.RegSize) } else if ctxt.HeadType == objabi.Hsolaris { ph := newElfPhdr() ph.Type = elf.PT_SUNWSTACK ph.Flags = elf.PF_W + elf.PF_R - } else if ctxt.HeadType == objabi.Hfreebsd { - ph := newElfPhdr() - ph.Type = elf.PT_GNU_STACK - ph.Flags = elf.PF_W + elf.PF_R - ph.Align = uint64(ctxt.Arch.RegSize) } elfobj: -- 2.48.1