public inbox for glibc-cvs@sourceware.org help / color / mirror / Atom feed
From: H.J. Lu <hjl@sourceware.org> To: glibc-cvs@sourceware.org Subject: [glibc] Enable DT_RELR in glibc shared libraries and PIEs automatically Date: Wed, 18 May 2022 20:04:25 +0000 (GMT) [thread overview] Message-ID: <20220518200425.E2E26387092A@sourceware.org> (raw) https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=2d5ec6692f5746ccb11db60976a6481ef8e9d74f commit 2d5ec6692f5746ccb11db60976a6481ef8e9d74f Author: H.J. Lu <hjl.tools@gmail.com> Date: Mon May 16 06:17:14 2022 -0700 Enable DT_RELR in glibc shared libraries and PIEs automatically Enable DT_RELR in glibc shared libraries and position independent executables (PIE) automatically if linker supports -z pack-relative-relocs. Reviewed-by: Florian Weimer <fweimer@redhat.com> Diff: --- Makeconfig | 12 ++++++++++++ Makerules | 2 ++ elf/Makefile | 5 ++++- 3 files changed, 18 insertions(+), 1 deletion(-) diff --git a/Makeconfig b/Makeconfig index b5aa07c4f4..ba70321af1 100644 --- a/Makeconfig +++ b/Makeconfig @@ -362,6 +362,15 @@ relro-LDFLAGS = -Wl,-z,relro LDFLAGS.so += $(relro-LDFLAGS) LDFLAGS-rtld += $(relro-LDFLAGS) +# Linker options to enable and disable DT_RELR. +ifeq ($(have-dt-relr),yes) +dt-relr-ldflag = -Wl,-z,pack-relative-relocs +no-dt-relr-ldflag = -Wl,-z,nopack-relative-relocs +else +dt-relr-ldflag = +no-dt-relr-ldflag = +endif + ifeq (no,$(build-pie-default)) pie-default = $(no-pie-ccflag) else # build-pie-default @@ -370,6 +379,7 @@ pic-default = -DPIC pie-default = $(pie-ccflag) ifeq (yes,$(enable-static-pie)) +static-pie-dt-relr-ldflag = $(dt-relr-ldflag) ifeq (yes,$(have-static-pie)) static-pie-ldflag = -static-pie else @@ -404,6 +414,7 @@ link-extra-libs-tests = $(libsupport) # Command for linking PIE programs with the C library. ifndef +link-pie +link-pie-before-inputs = $(if $($(@F)-no-pie),$(no-pie-ldflag),-pie) \ + $(if $($(@F)-no-dt-relr),$(no-dt-relr-ldflag),$(dt-relr-ldflag)) \ -Wl,-O1 -nostdlib -nostartfiles \ $(sysdep-LDFLAGS) $(LDFLAGS) $(LDFLAGS-$(@F)) \ $(relro-LDFLAGS) $(hashstyle-LDFLAGS) \ @@ -436,6 +447,7 @@ endif ifndef +link-static +link-static-before-inputs = -nostdlib -nostartfiles -static \ $(if $($(@F)-no-pie),$(no-pie-ldflag),$(static-pie-ldflag)) \ + $(if $($(@F)-no-dt-relr),$(no-dt-relr-ldflag),$(static-pie-dt-relr-ldflag)) \ $(sysdep-LDFLAGS) $(LDFLAGS) $(LDFLAGS-$(@F)) \ $(firstword $(CRT-$(@F)) $(csu-objpfx)$(real-static-start-installed-name)) \ $(+preinit) $(+prectorT) diff --git a/Makerules b/Makerules index 354528b8c7..dfe89e9e39 100644 --- a/Makerules +++ b/Makerules @@ -536,6 +536,7 @@ lib%.so: lib%_pic.a $(+preinit) $(+postinit) $(link-libc-deps) define build-shlib-helper $(LINK.o) -shared -static-libgcc -Wl,-O1 $(sysdep-LDFLAGS) \ $(if $($(@F)-no-z-defs)$(no-z-defs),,-Wl,-z,defs) $(rtld-LDFLAGS) \ + $(if $($(@F)-no-dt-relr),$(no-dt-relr-ldflag),$(dt-relr-ldflag)) \ $(extra-B-$(@F:lib%.so=%).so) -B$(csu-objpfx) \ $(extra-B-$(@F:lib%.so=%).so) $(load-map-file) \ -Wl,-soname=lib$(libprefix)$(@F:lib%.so=%).so$($(@F)-version) \ @@ -588,6 +589,7 @@ endef define build-module-helper $(LINK.o) -shared -static-libgcc $(sysdep-LDFLAGS) $(rtld-LDFLAGS) \ $(if $($(@F)-no-z-defs)$(no-z-defs),,-Wl,-z,defs) \ + $(if $($(@F)-no-dt-relr),$(no-dt-relr-ldflag),$(dt-relr-ldflag)) \ -B$(csu-objpfx) $(load-map-file) \ $(LDFLAGS.so) $(LDFLAGS-$(@F:%.so=%).so) \ $(link-test-modules-rpath-link) \ diff --git a/elf/Makefile b/elf/Makefile index ce3345ed92..6f4ea78007 100644 --- a/elf/Makefile +++ b/elf/Makefile @@ -1342,6 +1342,7 @@ $(objpfx)ld.so: $(objpfx)librtld.os $(ld-map) # if the sanity check below fails. $(LINK.o) -nostdlib -nostartfiles -shared -o $@.new \ $(LDFLAGS-rtld) -Wl,-z,defs $(z-now-$(bind-now)) \ + $(dt-relr-ldflag) \ $(filter-out $(map-file),$^) $(load-map-file) \ -Wl,-soname=$(rtld-installed-name) $(call after-link,$@.new) @@ -1666,6 +1667,7 @@ $(objpfx)nodlopen2.out: $(objpfx)nodlopenmod2.so $(objpfx)filtmod1.so: $(objpfx)filtmod1.os $(objpfx)filtmod2.so $(LINK.o) -shared -o $@ -B$(csu-objpfx) $(LDFLAGS.so) \ + $(dt-relr-ldflag) \ -L$(subst :, -L,$(rpath-link)) \ -Wl,-rpath-link=$(rpath-link) \ $< -Wl,-F,$(objpfx)filtmod2.so @@ -2469,7 +2471,7 @@ $(objpfx)tst-big-note: $(objpfx)tst-big-note-lib.so # artificial, large note in tst-big-note-lib.o and invalidate the # test. $(objpfx)tst-big-note-lib.so: $(objpfx)tst-big-note-lib.o - $(LINK.o) -shared -o $@ $(LDFLAGS.so) $< + $(LINK.o) -shared -o $@ $(LDFLAGS.so) $(dt-relr-ldflag) $< $(objpfx)tst-unwind-ctor: $(objpfx)tst-unwind-ctor-lib.so @@ -2778,6 +2780,7 @@ $(objpfx)tst-ro-dynamic: $(objpfx)tst-ro-dynamic-mod.so $(objpfx)tst-ro-dynamic-mod.so: $(objpfx)tst-ro-dynamic-mod.os \ tst-ro-dynamic-mod.map $(LINK.o) -nostdlib -nostartfiles -shared -o $@ \ + $(dt-relr-ldflag) \ -Wl,--script=tst-ro-dynamic-mod.map \ $(objpfx)tst-ro-dynamic-mod.os
reply other threads:[~2022-05-18 20:04 UTC|newest] Thread overview: [no followups] expand[flat|nested] mbox.gz Atom feed
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=20220518200425.E2E26387092A@sourceware.org \ --to=hjl@sourceware.org \ --cc=glibc-cvs@sourceware.org \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: linkBe sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions for how to clone and mirror all data and code used for this inbox; as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).