From 18991197b4b588255ccabf472ebc84db7b66a19c Mon Sep 17 00:00:00 2001 From: Roland McGrath Date: Thu, 19 Jul 2007 01:48:40 -0700 Subject: [PATCH] Use --build-id ld option This change passes the --build-id when linking the kernel and when linking modules, if ld supports it. This is a new GNU ld option that synthesizes an ELF note section inside the read-only data. The note in this section contains unique identifying bits called the "build ID", which are generated so as to be different for any two linked ELF files that aren't identical. The build ID can be recovered from stripped files, memory dumps, etc. and used to look up the original program built, locate debuginfo or other details or history associated with it. For normal program linking, the compiler passes --build-id to ld by default, but the option is needed when using ld directly as we do. Signed-off-by: Roland McGrath Cc: Andi Kleen Cc: Paul Mackerras Cc: Benjamin Herrenschmidt Cc: Richard Henderson Cc: Ivan Kokshaysky Cc: Martin Schwidefsky Cc: Heiko Carstens Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Makefile | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/Makefile b/Makefile index ddbfcac299c..eccb03b88b8 100644 --- a/Makefile +++ b/Makefile @@ -514,6 +514,12 @@ CFLAGS += $(call cc-option,-Wdeclaration-after-statement,) # disable pointer signed / unsigned warnings in gcc 4.0 CFLAGS += $(call cc-option,-Wno-pointer-sign,) +# Use --build-id when available. +LDFLAGS_BUILD_ID = $(patsubst -Wl$(comma)%,%,\ + $(call ld-option, -Wl$(comma)--build-id,)) +LDFLAGS_MODULE += $(LDFLAGS_BUILD_ID) +LDFLAGS_vmlinux += $(LDFLAGS_BUILD_ID) + # Default kernel image to build when no specific target is given. # KBUILD_IMAGE may be overruled on the command line or # set in the environment