diff options
| author | Masahiro Yamada <masahiroy@kernel.org> | 2020-12-18 11:45:40 +0900 |
|---|---|---|
| committer | Will Deacon <will@kernel.org> | 2021-01-20 12:18:46 +0000 |
| commit | a5b8ca97fbf8300a5e21c393df25ce6f521e7939 (patch) | |
| tree | e408b44b8200420fb5e05c14edacbf566dbb503e /arch | |
| parent | 19c329f6808995b142b3966301f217c831e7cf31 (diff) | |
arm64: do not descend to vdso directories twice
arm64 descends into each vdso directory twice; first in vdso_prepare,
second during the ordinary build process.
PPC mimicked it and uncovered a problem [1]. In the first descend,
Kbuild directly visits the vdso directories, therefore it does not
inherit subdir-ccflags-y from upper directories.
This means the command line parameters may differ between the two.
If it happens, the offset values in the generated headers might be
different from real offsets of vdso.so in the kernel.
This potential danger should be avoided. The vdso directories are
built in the vdso_prepare stage, so the second descend is unneeded.
[1]: https://lore.kernel.org/linux-kbuild/CAK7LNARAkJ3_-4gX0VA2UkapbOftuzfSTVMBbgbw=HD8n7N+7w@mail.gmail.com/T/#ma10dcb961fda13f36d42d58fa6cb2da988b7e73a
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Link: https://lore.kernel.org/r/20201218024540.1102650-1-masahiroy@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/arm64/Makefile | 10 | ||||
| -rw-r--r-- | arch/arm64/kernel/Makefile | 5 | ||||
| -rw-r--r-- | arch/arm64/kernel/vdso-wrap.S (renamed from arch/arm64/kernel/vdso/vdso.S) | 0 | ||||
| -rw-r--r-- | arch/arm64/kernel/vdso/Makefile | 1 | ||||
| -rw-r--r-- | arch/arm64/kernel/vdso32-wrap.S (renamed from arch/arm64/kernel/vdso32/vdso.S) | 0 | ||||
| -rw-r--r-- | arch/arm64/kernel/vdso32/Makefile | 1 |
6 files changed, 9 insertions, 8 deletions
diff --git a/arch/arm64/Makefile b/arch/arm64/Makefile index 90309208bb28..5b84aec31ed3 100644 --- a/arch/arm64/Makefile +++ b/arch/arm64/Makefile @@ -188,10 +188,12 @@ ifeq ($(KBUILD_EXTMOD),) # this hack. prepare: vdso_prepare vdso_prepare: prepare0 - $(Q)$(MAKE) $(build)=arch/arm64/kernel/vdso include/generated/vdso-offsets.h - $(if $(CONFIG_COMPAT_VDSO),$(Q)$(MAKE) \ - $(build)=arch/arm64/kernel/vdso32 \ - include/generated/vdso32-offsets.h) + $(Q)$(MAKE) $(build)=arch/arm64/kernel/vdso \ + include/generated/vdso-offsets.h arch/arm64/kernel/vdso/vdso.so +ifdef CONFIG_COMPAT_VDSO + $(Q)$(MAKE) $(build)=arch/arm64/kernel/vdso32 \ + include/generated/vdso32-offsets.h arch/arm64/kernel/vdso32/vdso.so +endif endif define archhelp diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile index 86364ab6f13f..42f6ad2c7eac 100644 --- a/arch/arm64/kernel/Makefile +++ b/arch/arm64/kernel/Makefile @@ -59,9 +59,10 @@ obj-$(CONFIG_CRASH_CORE) += crash_core.o obj-$(CONFIG_ARM_SDE_INTERFACE) += sdei.o obj-$(CONFIG_ARM64_PTR_AUTH) += pointer_auth.o obj-$(CONFIG_ARM64_MTE) += mte.o +obj-y += vdso-wrap.o +obj-$(CONFIG_COMPAT_VDSO) += vdso32-wrap.o -obj-y += vdso/ probes/ -obj-$(CONFIG_COMPAT_VDSO) += vdso32/ +obj-y += probes/ head-y := head.o extra-y += $(head-y) vmlinux.lds diff --git a/arch/arm64/kernel/vdso/vdso.S b/arch/arm64/kernel/vdso-wrap.S index c4b1990bf2be..c4b1990bf2be 100644 --- a/arch/arm64/kernel/vdso/vdso.S +++ b/arch/arm64/kernel/vdso-wrap.S diff --git a/arch/arm64/kernel/vdso/Makefile b/arch/arm64/kernel/vdso/Makefile index cd9c3fa25902..76c0255ecc91 100644 --- a/arch/arm64/kernel/vdso/Makefile +++ b/arch/arm64/kernel/vdso/Makefile @@ -44,7 +44,6 @@ endif # Disable gcov profiling for VDSO code GCOV_PROFILE := n -obj-y += vdso.o targets += vdso.lds CPPFLAGS_vdso.lds += -P -C -U$(ARCH) diff --git a/arch/arm64/kernel/vdso32/vdso.S b/arch/arm64/kernel/vdso32-wrap.S index e72ac7bc4c04..e72ac7bc4c04 100644 --- a/arch/arm64/kernel/vdso32/vdso.S +++ b/arch/arm64/kernel/vdso32-wrap.S diff --git a/arch/arm64/kernel/vdso32/Makefile b/arch/arm64/kernel/vdso32/Makefile index a1e0f91e6cea..789ad420f16b 100644 --- a/arch/arm64/kernel/vdso32/Makefile +++ b/arch/arm64/kernel/vdso32/Makefile @@ -155,7 +155,6 @@ c-obj-vdso-gettimeofday := $(addprefix $(obj)/, $(c-obj-vdso-gettimeofday)) asm-obj-vdso := $(addprefix $(obj)/, $(asm-obj-vdso)) obj-vdso := $(c-obj-vdso) $(c-obj-vdso-gettimeofday) $(asm-obj-vdso) -obj-y += vdso.o targets += vdso.lds CPPFLAGS_vdso.lds += -P -C -U$(ARCH) |