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| author | Catalin Marinas <catalin.marinas@arm.com> | 2016-07-08 14:13:20 +0300 |
|---|---|---|
| committer | Catalin Marinas <catalin.marinas@arm.com> | 2016-07-08 16:29:18 +0300 |
| commit | 90f777beb788d08300f4a1482cb4fd37a401b472 (patch) | |
| tree | 1dde16fbc3122b9ab29a60fae912b29460cd5ae1 /arch/arm64/kernel | |
| parent | 40f87d3114b8a1e730ac8f3dc3cf1efe33124776 (diff) | |
| download | linux-90f777beb788d08300f4a1482cb4fd37a401b472.tar.xz | |
arm64: Fix vdso-offsets.h dependency
arch/arm64/kernel/{vdso,signal}.c include generated/vdso-offsets.h, and
therefore the symbol offsets must be generated before these files are
compiled.
The current rules in arm64/kernel/Makefile do not actually enforce
this, because even though $(obj)/vdso is listed as a prerequisite for
vdso-offsets.h, this does not result in the intended effect of
building the vdso subdirectory (before all the other objects). As a
consequence, depending on the order in which the rules are followed,
vdso-offsets.h is updated or not before arm64/kernel/{vdso,signal}.o
are built. The current rules also impose an unnecessary dependency on
vdso-offsets.h for all arm64/kernel/*.o, resulting in unnecessary
rebuilds.
This patch removes the arch/arm64/kernel/vdso/vdso-offsets.h file
generation, leaving only the include/generated/vdso-offsets.h one. It
adds a forced dependency check of the vdso-offsets.h file in
arch/arm64/kernel/Makefile which, if not up to date according to the
arch/arm64/kernel/vdso/Makefile rules (depending on vdso.so.dbg), will
trigger the vdso/ subdirectory build and vdso-offsets.h re-generation.
Automatic kbuild dependency rules between kernel/{vdso,signal}.c rules
and vdso-offsets.h will guarantee that the vDSO object is built first,
followed by the generated symbol offsets header file.
Reported-by: Kevin Brodsky <kevin.brodsky@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch/arm64/kernel')
| -rw-r--r-- | arch/arm64/kernel/Makefile | 7 | ||||
| -rw-r--r-- | arch/arm64/kernel/vdso/Makefile | 7 |
2 files changed, 7 insertions, 7 deletions
diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile index 7700c0c23962..efffc231a244 100644 --- a/arch/arm64/kernel/Makefile +++ b/arch/arm64/kernel/Makefile @@ -54,6 +54,7 @@ obj-m += $(arm64-obj-m) head-y := head.o extra-y += $(head-y) vmlinux.lds -# vDSO - this must be built first to generate the symbol offsets -$(call objectify,$(arm64-obj-y)): $(obj)/vdso/vdso-offsets.h -$(obj)/vdso/vdso-offsets.h: $(obj)/vdso +# Check that the vDSO symbol offsets header file is up to date and re-generate +# it if necessary. +$(objtree)/include/generated/vdso-offsets.h: FORCE + $(Q)$(MAKE) $(build)=$(obj)/vdso $@ diff --git a/arch/arm64/kernel/vdso/Makefile b/arch/arm64/kernel/vdso/Makefile index b467fd0a384b..285433720202 100644 --- a/arch/arm64/kernel/vdso/Makefile +++ b/arch/arm64/kernel/vdso/Makefile @@ -23,7 +23,7 @@ GCOV_PROFILE := n ccflags-y += -Wl,-shared obj-y += vdso.o -extra-y += vdso.lds vdso-offsets.h +extra-y += vdso.lds CPPFLAGS_vdso.lds += -P -C -U$(ARCH) # Force dependency (incbin is bad) @@ -42,11 +42,10 @@ $(obj)/%.so: $(obj)/%.so.dbg FORCE gen-vdsosym := $(srctree)/$(src)/gen_vdso_offsets.sh quiet_cmd_vdsosym = VDSOSYM $@ define cmd_vdsosym - $(NM) $< | $(gen-vdsosym) | LC_ALL=C sort > $@ && \ - cp $@ include/generated/ + $(NM) $< | $(gen-vdsosym) | LC_ALL=C sort > $@ endef -$(obj)/vdso-offsets.h: $(obj)/vdso.so.dbg FORCE +$(objtree)/include/generated/vdso-offsets.h: $(obj)/vdso.so.dbg FORCE $(call if_changed,vdsosym) # Assembly rules for the .S files |