You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
51 lines
2.0 KiB
51 lines
2.0 KiB
9 months ago
|
commit abcc039d2e26b3c9c723d6419e086753a791b3d5
|
||
|
|
Author: Florian Weimer <fweimer@redhat.com>
|
||
|
|
Date: Fri Feb 7 20:06:32 2020 +0100
|
||
|
|
|
||
|
|
elf: Introduce the rtld-stubbed-symbols makefile variable
|
||
|
|
|
||
|
|
This generalizes a mechanism used for stack-protector support, so
|
||
|
|
that it can be applied to other symbols if required.
|
||
|
|
|
||
|
|
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
|
||
|
|
|
||
|
|
diff --git a/elf/Makefile b/elf/Makefile
|
||
|
|
index 4ab73dc48d9ac126..a1ea44f231d8cec5 100644
|
||
|
|
--- a/elf/Makefile
|
||
|
|
+++ b/elf/Makefile
|
||
|
|
@@ -474,21 +474,25 @@ $(objpfx)dl-allobjs.os: $(all-rtld-routines:%=$(objpfx)%.os)
|
||
|
|
# are compiled with special flags, and puts these modules into rtld-libc.a
|
||
|
|
# for us. Then we do the real link using rtld-libc.a instead of libc_pic.a.
|
||
|
|
|
||
|
|
-# If the compiler can do SSP, build the mapfile with dummy __stack_chk_fail
|
||
|
|
-# and __stack_chk_fail_local symbols defined, to prevent the real things
|
||
|
|
-# being dragged into rtld even though rtld is never built with stack-
|
||
|
|
-# protection.
|
||
|
|
+# These symbols need to be stubbed out during symbol discovery because
|
||
|
|
+# their implementation is provided differently in rtld, and the symbol
|
||
|
|
+# discovery mechanism is not compatible with the libc implementation
|
||
|
|
+# when compiled for libc.
|
||
|
|
+rtld-stubbed-symbols =
|
||
|
|
+
|
||
|
|
+# The GCC arguments that implement $(rtld-stubbed-symbols).
|
||
|
|
+rtld-stubbed-symbols-args = \
|
||
|
|
+ $(patsubst %,-Wl$(comma)--defsym=%=0, $(rtld-stubbed-symbols))
|
||
|
|
|
||
|
|
ifeq ($(have-ssp),yes)
|
||
|
|
-dummy-stack-chk-fail := -Wl,--defsym='__stack_chk_fail=0' \
|
||
|
|
- -Wl,--defsym='__stack_chk_fail_local=0'
|
||
|
|
-else
|
||
|
|
-dummy-stack-chk-fail :=
|
||
|
|
+# rtld is not built with the stack protector, so these references will
|
||
|
|
+# go away in the rebuilds.
|
||
|
|
+rtld-stubbed-symbols += __stack_chk_fail __stack_chk_fail_local
|
||
|
|
endif
|
||
|
|
|
||
|
|
$(objpfx)librtld.map: $(objpfx)dl-allobjs.os $(common-objpfx)libc_pic.a
|
||
|
|
@-rm -f $@T
|
||
|
|
- $(reloc-link) -o $@.o $(dummy-stack-chk-fail) \
|
||
|
|
+ $(reloc-link) -o $@.o $(rtld-stubbed-symbols-args) \
|
||
|
|
'-Wl,-(' $^ -lgcc '-Wl,-)' -Wl,-Map,$@T
|
||
|
|
rm -f $@.o
|
||
|
|
mv -f $@T $@
|