kbuild: make it possible for the linker to discard local symbols from vmlinux (5d7d18f5) · Commits · 戴 / test

Make it possible for the linker to discard local symbols from vmlinux as they cause vmlinux to balloon when CONFIG_KALLSYMS=y and they cause dump_stack() and get_wchan() to produce useless information under some circumstances. With this we add a config option (CONFIG_STRIP_ASM_SYMS) that will cause the build to supply -X to the linker to tell it to strip temporary local symbols. This doesn't seem to cause gdb any problems. Signed-off-by:

David Howells <dhowells@redhat.com> Signed-off-by:

Andrew Morton <akpm@linux-foundation.org> Signed-off-by:

Sam Ravnborg <sam@ravnborg.org>

Makefile

+4 −0

Original line number	Diff line number	Diff line
		@@ -597,6 +597,10 @@ LDFLAGS_BUILD_ID = $(patsubst -Wl$(comma)%,%,\
		LDFLAGS_MODULE += $(LDFLAGS_BUILD_ID)
		LDFLAGS_vmlinux += $(LDFLAGS_BUILD_ID)

		ifeq ($(CONFIG_STRIP_ASM_SYMS),y)
		LDFLAGS_vmlinux += -X
		endif

		# 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

init/Kconfig

+8 −0

Original line number	Diff line number	Diff line
		@@ -808,6 +808,14 @@ config KALLSYMS_EXTRA_PASS
		you wait for kallsyms to be fixed.


		config STRIP_ASM_SYMS
		bool "Strip assembler-generated symbols during link"
		default n
		help
		Strip internal assembler-generated symbols during a link (symbols
		that look like '.Lxxx') so they don't pollute the output of
		get_wchan() and suchlike.

		config HOTPLUG
		bool "Support for hot-pluggable devices" if EMBEDDED
		default y

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