mirror of
https://github.com/raspberrypi/linux.git
synced 2025-12-27 04:22:58 +00:00
bd71558d58
Since binutils 2.39, ld will print a warning if any stack section is
executable, which is the default for stack sections on files without a
.note.GNU-stack section.
This was fixed for x86 in commit ffcf9c5700 ("x86: link vdso and boot with -z noexecstack --no-warn-rwx-segments"),
but remained broken for UML, resulting in several warnings:
/usr/bin/ld: warning: arch/x86/um/vdso/vdso.o: missing .note.GNU-stack section implies executable stack
/usr/bin/ld: NOTE: This behaviour is deprecated and will be removed in a future version of the linker
/usr/bin/ld: warning: .tmp_vmlinux.kallsyms1 has a LOAD segment with RWX permissions
/usr/bin/ld: warning: .tmp_vmlinux.kallsyms1.o: missing .note.GNU-stack section implies executable stack
/usr/bin/ld: NOTE: This behaviour is deprecated and will be removed in a future version of the linker
/usr/bin/ld: warning: .tmp_vmlinux.kallsyms2 has a LOAD segment with RWX permissions
/usr/bin/ld: warning: .tmp_vmlinux.kallsyms2.o: missing .note.GNU-stack section implies executable stack
/usr/bin/ld: NOTE: This behaviour is deprecated and will be removed in a future version of the linker
/usr/bin/ld: warning: vmlinux has a LOAD segment with RWX permissions
Link both the VDSO and vmlinux with -z noexecstack, fixing the warnings
about .note.GNU-stack sections. In addition, pass --no-warn-rwx-segments
to dodge the remaining warnings about LOAD segments with RWX permissions
in the kallsyms objects. (Note that this flag is apparently not
available on lld, so hide it behind a test for BFD, which is what the
x86 patch does.)
Link: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=ffcf9c5700e49c0aee42dcba9a12ba21338e8136
Link: https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=ba951afb99912da01a6e8434126b8fac7aa75107
Signed-off-by: David Gow <davidgow@google.com>
Reviewed-by: Lukas Straub <lukasstraub2@web.de>
Tested-by: Lukas Straub <lukasstraub2@web.de>
Acked-by: Randy Dunlap <rdunlap@infradead.org> # build-tested
Signed-off-by: Richard Weinberger <richard@nod.at>
82 lines
2.1 KiB
Makefile
82 lines
2.1 KiB
Makefile
# SPDX-License-Identifier: GPL-2.0
|
|
#
|
|
# Building vDSO images for x86.
|
|
#
|
|
|
|
# do not instrument on vdso because KASAN is not compatible with user mode
|
|
KASAN_SANITIZE := n
|
|
|
|
# Prevents link failures: __sanitizer_cov_trace_pc() is not linked in.
|
|
KCOV_INSTRUMENT := n
|
|
|
|
VDSO64-y := y
|
|
|
|
vdso-install-$(VDSO64-y) += vdso.so
|
|
|
|
|
|
# files to link into the vdso
|
|
vobjs-y := vdso-note.o um_vdso.o
|
|
|
|
# files to link into kernel
|
|
obj-$(VDSO64-y) += vdso.o vma.o
|
|
|
|
vobjs := $(foreach F,$(vobjs-y),$(obj)/$F)
|
|
|
|
$(obj)/vdso.o: $(obj)/vdso.so
|
|
|
|
targets += vdso.so vdso.so.dbg vdso.lds $(vobjs-y)
|
|
|
|
CPPFLAGS_vdso.lds += -P -C
|
|
|
|
VDSO_LDFLAGS_vdso.lds = -m64 -Wl,-soname=linux-vdso.so.1 \
|
|
-Wl,-z,max-page-size=4096
|
|
|
|
$(obj)/vdso.o: $(src)/vdso.S $(obj)/vdso.so
|
|
|
|
$(obj)/vdso.so.dbg: $(obj)/vdso.lds $(vobjs) FORCE
|
|
$(call if_changed,vdso)
|
|
|
|
$(obj)/%.so: OBJCOPYFLAGS := -S
|
|
$(obj)/%.so: $(obj)/%.so.dbg FORCE
|
|
$(call if_changed,objcopy)
|
|
|
|
#
|
|
# Don't omit frame pointers for ease of userspace debugging, but do
|
|
# optimize sibling calls.
|
|
#
|
|
CFL := $(PROFILING) -mcmodel=small -fPIC -O2 -fasynchronous-unwind-tables -m64 \
|
|
$(filter -g%,$(KBUILD_CFLAGS)) -fno-stack-protector \
|
|
-fno-omit-frame-pointer -foptimize-sibling-calls
|
|
|
|
$(vobjs): KBUILD_CFLAGS += $(CFL)
|
|
|
|
#
|
|
# vDSO code runs in userspace and -pg doesn't help with profiling anyway.
|
|
#
|
|
CFLAGS_REMOVE_vdso-note.o = -pg -fprofile-arcs -ftest-coverage
|
|
CFLAGS_REMOVE_um_vdso.o = -pg -fprofile-arcs -ftest-coverage
|
|
|
|
#
|
|
# The DSO images are built using a special linker script.
|
|
#
|
|
quiet_cmd_vdso = VDSO $@
|
|
cmd_vdso = $(CC) -nostdlib -o $@ \
|
|
$(VDSO_LDFLAGS) $(VDSO_LDFLAGS_$(filter %.lds,$(^F))) \
|
|
-Wl,-T,$(filter %.lds,$^) $(filter %.o,$^) && \
|
|
sh $(srctree)/$(src)/checkundef.sh '$(NM)' '$@'
|
|
|
|
VDSO_LDFLAGS = -fPIC -shared -Wl,--hash-style=sysv -z noexecstack
|
|
GCOV_PROFILE := n
|
|
|
|
#
|
|
# Install the unstripped copy of vdso*.so listed in $(vdso-install-y).
|
|
#
|
|
quiet_cmd_vdso_install = INSTALL $@
|
|
cmd_vdso_install = cp $(obj)/$@.dbg $(MODLIB)/vdso/$@
|
|
$(vdso-install-y): %.so: $(obj)/%.so.dbg FORCE
|
|
@mkdir -p $(MODLIB)/vdso
|
|
$(call cmd,vdso_install)
|
|
|
|
PHONY += vdso_install $(vdso-install-y)
|
|
vdso_install: $(vdso-install-y)
|