Support after-link variable to run a final step on binaries.

This commit is contained in:
Roland McGrath 2015-02-12 13:38:47 -08:00
parent 87a629c5d7
commit 04f5a636b6
4 changed files with 51 additions and 12 deletions

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@ -1,3 +1,14 @@
2015-02-12 Roland McGrath <roland@hack.frob.com>
* Makeconfig (after-link): New variable.
(+link-pie, +link-pie-tests): Use it.
(+link-static, +link-static-tests): Likewise.
(+link, +link-tests): Likewise.
* Makerules (build-module, build-module-asneeded): Likewise.
(lib%.so, $(common-objpfx)libc.so, $(common-objpfx)linkobj/libc.so):
Likewise.
* elf/Makefile ($(objpfx)ld.so): Likewise.
2015-02-12 Rüdiger Sonderfeld <ruediger@c-plusplus.net>
[BZ #17965]

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@ -387,6 +387,14 @@ LDFLAGS.so += $(hashstyle-LDFLAGS)
LDFLAGS-rtld += $(hashstyle-LDFLAGS)
endif
# Command to run after every final link (executable or shared object).
# This is invoked with $(call after-link,...), so it should operate on
# the file $1. This can be set to do some sort of post-processing on
# binaries, or to perform some sort of static sanity check.
ifndef after-link
after-link =
endif
# Command for linking PIE programs with the C library.
ifndef +link-pie
+link-pie-before-libc = $(CC) -pie -Wl,-O1 -nostdlib -nostartfiles -o $@ \
@ -400,10 +408,15 @@ ifndef +link-pie
$(common-objpfx)libc% $(+postinit),$^) \
$(link-extra-libs)
+link-pie-after-libc = $(+postctorS) $(+postinit)
+link-pie = $(+link-pie-before-libc) $(rtld-LDFLAGS) $(link-libc) \
$(+link-pie-after-libc)
+link-pie-tests = $(+link-pie-before-libc) $(rtld-tests-LDFLAGS) \
$(link-libc-tests) $(+link-pie-after-libc)
define +link-pie
$(+link-pie-before-libc) $(rtld-LDFLAGS) $(link-libc) $(+link-pie-after-libc)
$(call after-link,$@)
endef
define +link-pie-tests
$(+link-pie-before-libc) $(rtld-tests-LDFLAGS) $(link-libc-tests) \
$(+link-pie-after-libc)
$(call after-link,$@)
endef
endif
# Command for statically linking programs with the C library.
ifndef +link-static
@ -417,10 +430,14 @@ ifndef +link-static
$(common-objpfx)libc% $(+postinit),$^) \
$(link-extra-libs-static)
+link-static-after-libc = $(+postctorT) $(+postinit)
+link-static = $(+link-static-before-libc) $(link-libc-static) \
$(+link-static-after-libc)
+link-static-tests = $(+link-static-before-libc) $(link-libc-static-tests) \
$(+link-static-after-libc)
define +link-static
$(+link-static-before-libc) $(link-libc-static) $(+link-static-after-libc)
$(call after-link,$@)
endef
define +link-static-tests
$(+link-static-before-libc) $(link-libc-static-tests) $(+link-static-after-libc)
$(call after-link,$@)
endef
endif
# Commands for linking programs with the C library.
ifndef +link
@ -436,10 +453,15 @@ ifeq (yes,$(build-shared))
$(common-objpfx)libc% $(+postinit),$^) \
$(link-extra-libs)
+link-after-libc = $(+postctor) $(+postinit)
+link = $(+link-before-libc) $(rtld-LDFLAGS) $(link-libc) \
$(+link-after-libc)
+link-tests = $(+link-before-libc) $(rtld-tests-LDFLAGS) \
$(link-libc-tests) $(+link-after-libc)
define +link
$(+link-before-libc) $(rtld-LDFLAGS) $(link-libc) $(+link-after-libc)
$(call after-link,$@)
endef
define +link-tests
$(+link-before-libc) $(rtld-tests-LDFLAGS) $(link-libc-tests) \
$(+link-after-libc)
$(call after-link,$@)
endef
else
+link = $(+link-static)
+link-tests = $(+link-static-tests)

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@ -505,6 +505,7 @@ link-libc-deps = $(common-objpfx)libc.so $(common-objpfx)linkobj/libc.so \
# to be as similar as possible to a default link with an installed libc.
lib%.so: lib%_pic.a $(+preinit) $(+postinit) $(link-libc-deps)
$(build-shlib) $(link-libc-args)
$(call after-link,$@)
define build-shlib-helper
$(LINK.o) -shared $(static-libgcc) -Wl,-O1 $(sysdep-LDFLAGS) \
@ -580,12 +581,14 @@ endef
define build-module
$(build-module-helper) -o $@ $(shlib-lds-flags) \
$(csu-objpfx)abi-note.o $(build-module-objlist) $(link-libc-args)
$(call after-link,$@)
endef
define build-module-asneeded
$(build-module-helper) -o $@ $(shlib-lds-flags) \
$(csu-objpfx)abi-note.o \
-Wl,--as-needed $(build-module-objlist) -Wl,--no-as-needed \
$(link-libc-args)
$(call after-link,$@)
endef
build-module-helper-objlist = \
@ -666,6 +669,7 @@ $(common-objpfx)libc.so: $(elf-objpfx)soinit.os \
$(elf-objpfx)ld.so \
$(shlib-lds)
$(build-shlib)
$(call after-link,$@)
$(common-objpfx)linkobj/libc.so: $(elf-objpfx)soinit.os \
$(common-objpfx)linkobj/libc_pic.a \
@ -674,6 +678,7 @@ $(common-objpfx)linkobj/libc.so: $(elf-objpfx)soinit.os \
$(elf-objpfx)ld.so \
$(shlib-lds)
$(build-shlib)
$(call after-link,$@)
ifeq ($(build-shared),yes)
$(common-objpfx)libc.so: $(common-objpfx)libc.map

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@ -349,6 +349,7 @@ $(objpfx)ld.so: $(objpfx)librtld.os $(ld-map)
$(filter-out $(map-file),$^) $(load-map-file) \
-Wl,-soname=$(rtld-installed-name) \
-Wl,-defsym=_begin=0
$(call after-link,$@.new)
$(READELF) -s $@.new \
| $(AWK) '($$7 ~ /^UND(|EF)$$/ && $$1 != "0:" && $$4 != "REGISTER") { print; p=1 } END { exit p != 0 }'
mv -f $@.new $@