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| author | Andreas Gruenbacher <agruen@suse.de> | 2008-12-01 14:21:01 -0800 |
|---|---|---|
| committer | Sam Ravnborg <sam@ravnborg.org> | 2008-12-03 22:33:11 +0100 |
| commit | 64e6c1e12372840e7caf8e25325a9e9c5fd370e6 (patch) | |
| tree | aa47aa4e170dd4bb39c99cc7356231e2c61d64d2 /scripts/Makefile.build | |
| parent | a680eedc6c621c75695c68198533fc3c98f4053b (diff) | |
| download | lwn-64e6c1e12372840e7caf8e25325a9e9c5fd370e6.tar.gz lwn-64e6c1e12372840e7caf8e25325a9e9c5fd370e6.zip | |
genksyms: track symbol checksum changes
Sometimes it is preferable to avoid changes of exported symbol checksums
(to avoid breaking externally provided modules). When a checksum change
occurs, it can be hard to figure out what caused this change: underlying
types may have changed, or additional type information may simply have
become available at the point where a symbol is exported.
Add a new --reference option to genksyms which allows it to report why
checksums change, based on the type information dumps it creates with the
--dump-types flag. Genksyms will read in such a dump from a previous run,
and report which symbols have changed (and why).
The behavior can be controlled for an entire build as follows: If
KBUILD_SYMTYPES is set, genksyms uses --dump-types to produce *.symtypes
dump files. If any *.symref files exist, those will be used as the
reference to check against. If KBUILD_PRESERVE is set, checksum changes
will fail the build.
Signed-off-by: Andreas Gruenbacher <agruen@suse.de>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Diffstat (limited to 'scripts/Makefile.build')
| -rw-r--r-- | scripts/Makefile.build | 16 |
1 files changed, 13 insertions, 3 deletions
diff --git a/scripts/Makefile.build b/scripts/Makefile.build index 468fbc9016c7..d21f0eac2e52 100644 --- a/scripts/Makefile.build +++ b/scripts/Makefile.build @@ -153,12 +153,18 @@ $(obj)/%.i: $(src)/%.c FORCE quiet_cmd_cc_symtypes_c = SYM $(quiet_modtag) $@ cmd_cc_symtypes_c = \ + set -e; \ $(CPP) -D__GENKSYMS__ $(c_flags) $< \ - | $(GENKSYMS) -T $@ >/dev/null; \ + | $(GENKSYMS) -T $@ \ + -r $(firstword $(wildcard \ + $(@:.symtypes=.symref) /dev/null)) \ + $(if $(KBUILD_PRESERVE),-p) \ + -a $(ARCH) \ + >/dev/null; \ test -s $@ || rm -f $@ $(obj)/%.symtypes : $(src)/%.c FORCE - $(call if_changed_dep,cc_symtypes_c) + $(call cmd,cc_symtypes_c) # C (.c) files # The C file is compiled and updated dependency information is generated. @@ -187,7 +193,11 @@ cmd_modversions = \ if $(OBJDUMP) -h $(@D)/.tmp_$(@F) | grep -q __ksymtab; then \ $(CPP) -D__GENKSYMS__ $(c_flags) $< \ | $(GENKSYMS) $(if $(KBUILD_SYMTYPES), \ - -T $(@D)/$(@F:.o=.symtypes)) -a $(ARCH) \ + -T $(@:.o=.symtypes)) \ + -r $(firstword $(wildcard \ + $(@:.o=.symref) /dev/null)) \ + $(if $(KBUILD_PRESERVE),-p) \ + -a $(ARCH) \ > $(@D)/.tmp_$(@F:.o=.ver); \ \ $(LD) $(LDFLAGS) -r -o $@ $(@D)/.tmp_$(@F) \ |