linux/lib/vdso/Makefile

# SPDX-License-Identifier: GPL-2.0

GENERIC_VDSO_MK_PATH := $(abspath $(lastword $(MAKEFILE_LIST)))
GENERIC_VDSO_DIR := $(dir $(GENERIC_VDSO_MK_PATH))

c-gettimeofday-$(CONFIG_GENERIC_GETTIMEOFDAY) := $(addprefix $(GENERIC_VDSO_DIR), gettimeofday.c)

# This cmd checks that the vdso library does not contain absolute relocation
# It has to be called after the linking of the vdso library and requires it
# as a parameter.
#
# $(ARCH_REL_TYPE_ABS) is defined in the arch specific makefile and corresponds
# to the absolute relocation types printed by "objdump -R" and accepted by the
# dynamic linker.
ifndef ARCH_REL_TYPE_ABS
$(error ARCH_REL_TYPE_ABS is not set)
endif

quiet_cmd_vdso_check = VDSOCHK $@
      cmd_vdso_check = if $(OBJDUMP) -R $@ | egrep -h "$(ARCH_REL_TYPE_ABS)"; \
		       then (echo >&2 "$@: dynamic relocations are not supported"; \
			     rm -f $@; /bin/false); fi
lib/vdso: Provide generic VDSO implementation In the last few years the kernel gained quite some architecture specific vdso implementations which contain very similar code. Introduce a generic VDSO implementation of gettimeofday() which will be shareable between architectures once they are converted over. The implementation is based on the current x86 VDSO code. [ tglx: Massaged changelog and made the kernel doc tabular ] Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Shijith Thotton <sthotton@marvell.com> Tested-by: Andre Przywara <andre.przywara@arm.com> Cc: linux-arch@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org Cc: linux-mips@vger.kernel.org Cc: linux-kselftest@vger.kernel.org Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Russell King <linux@armlinux.org.uk> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Paul Burton <paul.burton@mips.com> Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: Mark Salyzyn <salyzyn@android.com> Cc: Peter Collingbourne <pcc@google.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Dmitry Safonov <0x7f454c46@gmail.com> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Huw Davies <huw@codeweavers.com> Link: https://lkml.kernel.org/r/20190621095252.32307-3-vincenzo.frascino@arm.com 2019-06-21 09:52:29 +00:00			`# SPDX-License-Identifier: GPL-2.0`

			`GENERIC_VDSO_MK_PATH := $(abspath $(lastword $(MAKEFILE_LIST)))`
			`GENERIC_VDSO_DIR := $(dir $(GENERIC_VDSO_MK_PATH))`

			`c-gettimeofday-$(CONFIG_GENERIC_GETTIMEOFDAY) := $(addprefix $(GENERIC_VDSO_DIR), gettimeofday.c)`

			`# This cmd checks that the vdso library does not contain absolute relocation`
			`# It has to be called after the linking of the vdso library and requires it`
			`# as a parameter.`
			`#`
			`# $(ARCH_REL_TYPE_ABS) is defined in the arch specific makefile and corresponds`
			`# to the absolute relocation types printed by "objdump -R" and accepted by the`
			`# dynamic linker.`
			`ifndef ARCH_REL_TYPE_ABS`
			`$(error ARCH_REL_TYPE_ABS is not set)`
			`endif`

			`quiet_cmd_vdso_check = VDSOCHK $@`
			`cmd_vdso_check = if $(OBJDUMP) -R $@ \| egrep -h "$(ARCH_REL_TYPE_ABS)"; \`
			`then (echo >&2 "$@: dynamic relocations are not supported"; \`
			`rm -f $@; /bin/false); fi`