| Message ID | 20220208184309.148192-3-nick.alcock@oracle.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v8,1/6] kbuild: bring back tristate.conf | expand |
On Wed, Feb 9, 2022 at 3:44 AM Nick Alcock <nick.alcock@oracle.com> wrote: > > This is similar to modules.builtin, and constructed in a similar way to > the way that used to be built before commit > 8b41fc4454e36fbfdbb23f940d023d4dece2de29, via tristate.conf inclusion > and recursive concatenation up the tree. Unlike modules.builtin, > modules_thick.builtin givs the names of the object files that make up > modules that are comprised of more than one object file, using a syntax > similar to that of makefiles, e.g.: > > crypto/crypto.o: crypto/api.o crypto/cipher.o crypto/compress.o crypto/memneq.o > crypto/crypto_algapi.o: crypto/algapi.o crypto/proc.o crypto/scatterwalk.o > crypto/aead.o: > crypto/geniv.o: > > (where the latter two are single-file modules). > > An upcoming commit will use this mapping to populate /proc/kallmodsyms. > > A parser is included that yields a stram of (module, objfile name[]) > mappings: it's a bit baroque, but then parsing text files in C is quite > painful, and I'd rather put the complexity in here than in its callers. > The parser is not built in this commit, nor does it have any callers > yet; nor is any rule added that causes modules_thick.builtin to actually > be constructed. (Again, see a later commit for that.) > > I am not wedded to the approach used to construct this file, but I don't > see any other way to do it despite spending a week or so trying to tie > it into Kbuild without using a separate Makefile.modbuiltin: unlike the > names of builtin modules (which are also recorded in the source files > themseves via MODULE_*() macros) the mapping from object file name to > built-in module name is not recorded anywhere but in the makefiles > themselves, so we have to at least reparse them with something to > indicate the builtin-ness of each module (i.e., tristate.conf) if we are > to figure out which modules are built-in and which are not. > > Signed-off-by: Nick Alcock <nick.alcock@oracle.com> > Reviewed-by: Kris Van Hees <kris.van.hees@oracle.com> modules.builtin was initially implemented in a terrible way, hence I cleaned up the code and removed the double recursion of the source tree. Honestly, I do not want to see you bringing back all the bloat. > --- > .gitignore | 1 + > Documentation/dontdiff | 1 + > Makefile | 19 +++- > scripts/Kbuild.include | 6 ++ > scripts/Makefile.modbuiltin | 56 ++++++++++ > scripts/modules_thick.c | 200 ++++++++++++++++++++++++++++++++++++ > scripts/modules_thick.h | 48 +++++++++ > 7 files changed, 330 insertions(+), 1 deletion(-) > create mode 100644 scripts/Makefile.modbuiltin > create mode 100644 scripts/modules_thick.c > create mode 100644 scripts/modules_thick.h > > diff --git a/.gitignore b/.gitignore > index 7afd412dadd2..b49cd96f587a 100644 > --- a/.gitignore > +++ b/.gitignore > @@ -49,6 +49,7 @@ > *.zst > Module.symvers > modules.order > +modules_thick.builtin > > # > # Top-level generic files > diff --git a/Documentation/dontdiff b/Documentation/dontdiff > index 910b30a2a7d9..6a78988547d0 100644 > --- a/Documentation/dontdiff > +++ b/Documentation/dontdiff > @@ -183,6 +183,7 @@ modules.builtin > modules.builtin.modinfo > modules.nsdeps > modules.order > +modules_thick.builtin > modversions.h* > nconf > nconf-cfg > diff --git a/Makefile b/Makefile > index 199b6f388484..5e823fe8390f 100644 > --- a/Makefile > +++ b/Makefile > @@ -1470,6 +1470,23 @@ __modinst_pre: > > endif # CONFIG_MODULES > > +# modules_thick.builtin maps from kernel modules (or rather the object file > +# names they would have had had they not been built in) to their constituent > +# object files: we can use this to determine which modules any given object > +# file is part of. (We cannot eliminate the slight redundancy here without > +# double-expansion.) > + > +modthickbuiltin-files := $(addsuffix /modules_thick.builtin, $(build-dirs)) > + > +modules_thick.builtin: $(modthickbuiltin-files) > + $(Q)$(AWK) '!x[$$0]++' $(addsuffix /$@, $(build-dirs)) > $@ > + > +# tristate.conf is not included from this Makefile. Add it as a prerequisite > +# here to make it self-healing in case somebody accidentally removes it. > +$(modthickbuiltin-files): include/config/tristate.conf > + $(Q)$(MAKE) $(modbuiltin)=$(patsubst %/modules_thick.builtin,%,$@) builtin-file=modules_thick.builtin > + > + > ### > # Cleaning is done on three levels. > # make clean Delete most generated files > @@ -1849,7 +1866,7 @@ clean: $(clean-dirs) > -o -name '*.lex.c' -o -name '*.tab.[ch]' \ > -o -name '*.asn1.[ch]' \ > -o -name '*.symtypes' -o -name 'modules.order' \ > - -o -name '.tmp_*.o.*' \ > + -o -name '.tmp_*.o.*' -o -name modules_thick.builtin \ > -o -name '*.c.[012]*.*' \ > -o -name '*.ll' \ > -o -name '*.gcno' \ > diff --git a/scripts/Kbuild.include b/scripts/Kbuild.include > index 3514c2149e9d..167bbbd5fdf5 100644 > --- a/scripts/Kbuild.include > +++ b/scripts/Kbuild.include > @@ -74,6 +74,12 @@ endef > # $(Q)$(MAKE) $(build)=dir > build := -f $(srctree)/scripts/Makefile.build obj > > +### > +# Shorthand for $(Q)$(MAKE) -f scripts/Makefile.modbuiltin obj= > +# Usage: > +# $(Q)$(MAKE) $(modbuiltin)=dir > +modbuiltin := -f $(srctree)/scripts/Makefile.modbuiltin obj > + > ### > # Shorthand for $(Q)$(MAKE) -f scripts/Makefile.dtbinst obj= > # Usage: > diff --git a/scripts/Makefile.modbuiltin b/scripts/Makefile.modbuiltin > new file mode 100644 > index 000000000000..a27b692ea795 > --- /dev/null > +++ b/scripts/Makefile.modbuiltin > @@ -0,0 +1,56 @@ > +# SPDX-License-Identifier: GPL-2.0 > +# ========================================================================== > +# Generating modules_thick.builtin > +# ========================================================================== > + > +src := $(obj) > + > +PHONY := __modbuiltin > +__modbuiltin: > + > +include include/config/auto.conf > +# tristate.conf sets tristate variables to uppercase 'Y' or 'M' > +# That way, we get the list of built-in modules in obj-Y > +include include/config/tristate.conf > + > +include scripts/Kbuild.include > + > +ifdef building_out_of_srctree > +# Create output directory if not already present > +_dummy := $(shell [ -d $(obj) ] || mkdir -p $(obj)) > +endif > + > +# The filename Kbuild has precedence over Makefile > +kbuild-dir := $(if $(filter /%,$(src)),$(src),$(srctree)/$(src)) > +kbuild-file := $(if $(wildcard $(kbuild-dir)/Kbuild),$(kbuild-dir)/Kbuild,$(kbuild-dir)/Makefile) > +include $(kbuild-file) > + > +include scripts/Makefile.lib > + > +modthickbuiltin-subdirs := $(patsubst %,%/modules_thick.builtin, $(subdir-ym)) > +modthickbuiltin-target := $(obj)/modules_thick.builtin > + > +__modbuiltin: $(obj)/$(builtin-file) $(subdir-ym) > + @: > + > +$(modthickbuiltin-target): $(subdir-ym) FORCE > + $(Q) rm -f $@ > + $(Q) $(foreach mod-o, $(filter %.o,$(obj-Y)),\ > + printf "%s:" $(addprefix $(obj)/,$(mod-o)) >> $@; \ > + printf " %s" $(sort $(strip $(addprefix $(obj)/,$($(mod-o:.o=-objs)) \ > + $($(mod-o:.o=-y)) $($(mod-o:.o=-Y))))) >> $@; \ > + printf "\n" >> $@; ) \ > + cat /dev/null $(modthickbuiltin-subdirs) >> $@; > + > +PHONY += FORCE > + > +FORCE: > + > +# Descending > +# --------------------------------------------------------------------------- > + > +PHONY += $(subdir-ym) > +$(subdir-ym): > + $(Q)$(MAKE) $(modbuiltin)=$@ builtin-file=$(builtin-file) > + > +.PHONY: $(PHONY) > diff --git a/scripts/modules_thick.c b/scripts/modules_thick.c > new file mode 100644 > index 000000000000..9a15e99c1330 > --- /dev/null > +++ b/scripts/modules_thick.c > @@ -0,0 +1,200 @@ > +/* SPDX-License-Identifier: GPL-2.0 */ > +/* > + * A simple modules_thick reader. > + * > + * (C) 2014, 2021 Oracle, Inc. All rights reserved. > + * > + * This program is free software; you can redistribute it and/or modify > + * it under the terms of the GNU General Public License as published by > + * the Free Software Foundation; either version 2 of the License, or > + * (at your option) any later version. > + */ > + > +#include <errno.h> > +#include <stdio.h> > +#include <stdlib.h> > +#include <string.h> > + > +#include "modules_thick.h" > + > +/* > + * Read a modules_thick.builtin file and translate it into a stream of > + * name / module-name pairs. > + */ > + > +/* > + * Construct a modules_thick.builtin iterator. > + */ > +struct modules_thick_iter * > +modules_thick_iter_new(const char *modules_thick_file) > +{ > + struct modules_thick_iter *i; > + > + i = calloc(1, sizeof(struct modules_thick_iter)); > + if (i == NULL) > + return NULL; > + > + i->f = fopen(modules_thick_file, "r"); > + > + if (i->f == NULL) { > + fprintf(stderr, "Cannot open builtin module file %s: %s\n", > + modules_thick_file, strerror(errno)); > + return NULL; > + } > + > + return i; > +} > + > +/* > + * Iterate, returning a new null-terminated array of object file names, and a > + * new dynamically-allocated module name. (The module name passed in is freed.) > + * > + * The array of object file names should be freed by the caller: the strings it > + * points to are owned by the iterator, and should not be freed. > + */ > + > +char ** __attribute__((__nonnull__)) > +modules_thick_iter_next(struct modules_thick_iter *i, char **module_name) > +{ > + size_t npaths = 1; > + char **module_paths; > + char *last_slash; > + char *last_dot; > + char *trailing_linefeed; > + char *object_name = i->line; > + char *dash; > + int composite = 0; > + > + /* > + * Read in all module entries, computing the suffixless, pathless name > + * of the module and building the next arrayful of object file names for > + * return. > + * > + * Modules can consist of multiple files: in this case, the portion > + * before the colon is the path to the module (as before): the portion > + * after the colon is a space-separated list of files that should be > + * considered part of this module. In this case, the portion before the > + * name is an "object file" that does not actually exist: it is merged > + * into built-in.a without ever being written out. > + * > + * All module names have - translated to _, to match what is done to the > + * names of the same things when built as modules. > + */ > + > + /* > + * Reinvocation of exhausted iterator. Return NULL, once. > + */ > +retry: > + if (getline(&i->line, &i->line_size, i->f) < 0) { > + if (ferror(i->f)) { > + fprintf(stderr, "Error reading from modules_thick file:" > + " %s\n", strerror(errno)); > + exit(1); > + } > + rewind(i->f); > + return NULL; > + } > + > + if (i->line[0] == '\0') > + goto retry; > + > + /* > + * Slice the line in two at the colon, if any. If there is anything > + * past the ': ', this is a composite module. (We allow for no colon > + * for robustness, even though one should always be present.) > + */ > + if (strchr(i->line, ':') != NULL) { > + char *name_start; > + > + object_name = strchr(i->line, ':'); > + *object_name = '\0'; > + object_name++; > + name_start = object_name + strspn(object_name, " \n"); > + if (*name_start != '\0') { > + composite = 1; > + object_name = name_start; > + } > + } > + > + /* > + * Figure out the module name. > + */ > + last_slash = strrchr(i->line, '/'); > + last_slash = (!last_slash) ? i->line : > + last_slash + 1; > + free(*module_name); > + *module_name = strdup(last_slash); > + dash = *module_name; > + > + while (dash != NULL) { > + dash = strchr(dash, '-'); > + if (dash != NULL) > + *dash = '_'; > + } > + > + last_dot = strrchr(*module_name, '.'); > + if (last_dot != NULL) > + *last_dot = '\0'; > + > + trailing_linefeed = strchr(object_name, '\n'); > + if (trailing_linefeed != NULL) > + *trailing_linefeed = '\0'; > + > + /* > + * Multifile separator? Object file names explicitly stated: > + * slice them up and shuffle them in. > + * > + * The array size may be an overestimate if any object file > + * names start or end with spaces (very unlikely) but cannot be > + * an underestimate. (Check for it anyway.) > + */ > + if (composite) { > + char *one_object; > + > + for (npaths = 0, one_object = object_name; > + one_object != NULL; > + npaths++, one_object = strchr(one_object + 1, ' ')); > + } > + > + module_paths = malloc((npaths + 1) * sizeof(char *)); > + if (!module_paths) { > + fprintf(stderr, "%s: out of memory on module %s\n", __func__, > + *module_name); > + exit(1); > + } > + > + if (composite) { > + char *one_object; > + size_t i = 0; > + > + while ((one_object = strsep(&object_name, " ")) != NULL) { > + if (i >= npaths) { > + fprintf(stderr, "%s: num_objs overflow on module " > + "%s: this is a bug.\n", __func__, > + *module_name); > + exit(1); > + } > + > + module_paths[i++] = one_object; > + } > + } else > + module_paths[0] = i->line; /* untransformed module name */ > + > + module_paths[npaths] = NULL; > + > + return module_paths; > +} > + > +/* > + * Free an iterator. Can be called while iteration is underway, so even > + * state that is freed at the end of iteration must be freed here too. > + */ > +void > +modules_thick_iter_free(struct modules_thick_iter *i) > +{ > + if (i == NULL) > + return; > + fclose(i->f); > + free(i->line); > + free(i); > +} > diff --git a/scripts/modules_thick.h b/scripts/modules_thick.h > new file mode 100644 > index 000000000000..f5edcaf9550c > --- /dev/null > +++ b/scripts/modules_thick.h > @@ -0,0 +1,48 @@ > +/* SPDX-License-Identifier: GPL-2.0 */ > +/* > + * A simple modules_thick reader. > + * > + * (C) 2014, 2021 Oracle, Inc. All rights reserved. > + * > + * This program is free software; you can redistribute it and/or modify > + * it under the terms of the GNU General Public License as published by > + * the Free Software Foundation; either version 2 of the License, or > + * (at your option) any later version. > + */ > + > +#ifndef _LINUX_MODULES_THICK_H > +#define _LINUX_MODULES_THICK_H > + > +#include <stdio.h> > +#include <stddef.h> > + > +/* > + * modules_thick.builtin iteration state. > + */ > +struct modules_thick_iter { > + FILE *f; > + char *line; > + size_t line_size; > +}; > + > +/* > + * Construct a modules_thick.builtin iterator. > + */ > +struct modules_thick_iter * > +modules_thick_iter_new(const char *modules_thick_file); > + > +/* > + * Iterate, returning a new null-terminated array of object file names, and a > + * new dynamically-allocated module name. (The module name passed in is freed.) > + * > + * The array of object file names should be freed by the caller: the strings it > + * points to are owned by the iterator, and should not be freed. > + */ > + > +char ** __attribute__((__nonnull__)) > +modules_thick_iter_next(struct modules_thick_iter *i, char **module_name); > + > +void > +modules_thick_iter_free(struct modules_thick_iter *i); > + > +#endif > -- > 2.35.0.260.gb82b153193.dirty >
On 10 Feb 2022, Masahiro Yamada told this: > On Wed, Feb 9, 2022 at 3:44 AM Nick Alcock <nick.alcock@oracle.com> wrote: >> >> I am not wedded to the approach used to construct this file, but I don't >> see any other way to do it despite spending a week or so trying to tie >> it into Kbuild without using a separate Makefile.modbuiltin: unlike the >> names of builtin modules (which are also recorded in the source files >> themseves via MODULE_*() macros) the mapping from object file name to >> built-in module name is not recorded anywhere but in the makefiles >> themselves, so we have to at least reparse them with something to >> indicate the builtin-ness of each module (i.e., tristate.conf) if we are >> to figure out which modules are built-in and which are not. >> >> Signed-off-by: Nick Alcock <nick.alcock@oracle.com> >> Reviewed-by: Kris Van Hees <kris.van.hees@oracle.com> > > modules.builtin was initially implemented in a terrible way, > hence I cleaned up the code and removed the double recursion > of the source tree. That's why I said I was not wedded to this approach, and I'd be happy to use another one. I tried to reimplement it using a single recursion, but it seems to be impossible or at least very difficult, since you have to somehow interpret each target in the tree in two ways ("build this" versus "figure out whether this is built-in or not): if you can think up a trick, I'll give it a try. I tried to make the core Kbuild makefiles interpret obj-Y suitably, which might mean you could build the whole tree with tristate.conf in force as it is in Makefile.modbuiltin, but got lost in the tangle: and in any case doing that seemed far more invasive and far more likely to be rejected than just bringing back Makefile.modbuiltin. But for now, to me, this seems tolerable. The time costs of building modules_thick.builtin are so minimal I cannot determine them in a normal parallel build, well down in the noise, unless your machine is so short of memory that it can't even cache the directory tree walk (and with the cache hot, even with -j 1 building it takes only half a second). The maintenance costs appear to be basically zero as well: one file, not tightly coupled to the rest (the only coupling it has is the same coupling as every makefile in the build tree). Also one file that was present for decades already :) So... honestly, I don't see your objection. What's terrible about scripts/Makefile.modbuiltin? If it's so terrible, do you have an alternative way to do what it does in this patch series? > Honestly, I do not want to see you bringing back > all the bloat. It's come back because I find it necessary for the series which follows, which surely makes it not bloat. If you can think of another approach that can similarly figure out which modules are built in and which are not, I'd be happy to use it, but I can't think of one.
diff --git a/.gitignore b/.gitignore index 7afd412dadd2..b49cd96f587a 100644 --- a/.gitignore +++ b/.gitignore @@ -49,6 +49,7 @@ *.zst Module.symvers modules.order +modules_thick.builtin # # Top-level generic files diff --git a/Documentation/dontdiff b/Documentation/dontdiff index 910b30a2a7d9..6a78988547d0 100644 --- a/Documentation/dontdiff +++ b/Documentation/dontdiff @@ -183,6 +183,7 @@ modules.builtin modules.builtin.modinfo modules.nsdeps modules.order +modules_thick.builtin modversions.h* nconf nconf-cfg diff --git a/Makefile b/Makefile index 199b6f388484..5e823fe8390f 100644 --- a/Makefile +++ b/Makefile @@ -1470,6 +1470,23 @@ __modinst_pre: endif # CONFIG_MODULES +# modules_thick.builtin maps from kernel modules (or rather the object file +# names they would have had had they not been built in) to their constituent +# object files: we can use this to determine which modules any given object +# file is part of. (We cannot eliminate the slight redundancy here without +# double-expansion.) + +modthickbuiltin-files := $(addsuffix /modules_thick.builtin, $(build-dirs)) + +modules_thick.builtin: $(modthickbuiltin-files) + $(Q)$(AWK) '!x[$$0]++' $(addsuffix /$@, $(build-dirs)) > $@ + +# tristate.conf is not included from this Makefile. Add it as a prerequisite +# here to make it self-healing in case somebody accidentally removes it. +$(modthickbuiltin-files): include/config/tristate.conf + $(Q)$(MAKE) $(modbuiltin)=$(patsubst %/modules_thick.builtin,%,$@) builtin-file=modules_thick.builtin + + ### # Cleaning is done on three levels. # make clean Delete most generated files @@ -1849,7 +1866,7 @@ clean: $(clean-dirs) -o -name '*.lex.c' -o -name '*.tab.[ch]' \ -o -name '*.asn1.[ch]' \ -o -name '*.symtypes' -o -name 'modules.order' \ - -o -name '.tmp_*.o.*' \ + -o -name '.tmp_*.o.*' -o -name modules_thick.builtin \ -o -name '*.c.[012]*.*' \ -o -name '*.ll' \ -o -name '*.gcno' \ diff --git a/scripts/Kbuild.include b/scripts/Kbuild.include index 3514c2149e9d..167bbbd5fdf5 100644 --- a/scripts/Kbuild.include +++ b/scripts/Kbuild.include @@ -74,6 +74,12 @@ endef # $(Q)$(MAKE) $(build)=dir build := -f $(srctree)/scripts/Makefile.build obj +### +# Shorthand for $(Q)$(MAKE) -f scripts/Makefile.modbuiltin obj= +# Usage: +# $(Q)$(MAKE) $(modbuiltin)=dir +modbuiltin := -f $(srctree)/scripts/Makefile.modbuiltin obj + ### # Shorthand for $(Q)$(MAKE) -f scripts/Makefile.dtbinst obj= # Usage: diff --git a/scripts/Makefile.modbuiltin b/scripts/Makefile.modbuiltin new file mode 100644 index 000000000000..a27b692ea795 --- /dev/null +++ b/scripts/Makefile.modbuiltin @@ -0,0 +1,56 @@ +# SPDX-License-Identifier: GPL-2.0 +# ========================================================================== +# Generating modules_thick.builtin +# ========================================================================== + +src := $(obj) + +PHONY := __modbuiltin +__modbuiltin: + +include include/config/auto.conf +# tristate.conf sets tristate variables to uppercase 'Y' or 'M' +# That way, we get the list of built-in modules in obj-Y +include include/config/tristate.conf + +include scripts/Kbuild.include + +ifdef building_out_of_srctree +# Create output directory if not already present +_dummy := $(shell [ -d $(obj) ] || mkdir -p $(obj)) +endif + +# The filename Kbuild has precedence over Makefile +kbuild-dir := $(if $(filter /%,$(src)),$(src),$(srctree)/$(src)) +kbuild-file := $(if $(wildcard $(kbuild-dir)/Kbuild),$(kbuild-dir)/Kbuild,$(kbuild-dir)/Makefile) +include $(kbuild-file) + +include scripts/Makefile.lib + +modthickbuiltin-subdirs := $(patsubst %,%/modules_thick.builtin, $(subdir-ym)) +modthickbuiltin-target := $(obj)/modules_thick.builtin + +__modbuiltin: $(obj)/$(builtin-file) $(subdir-ym) + @: + +$(modthickbuiltin-target): $(subdir-ym) FORCE + $(Q) rm -f $@ + $(Q) $(foreach mod-o, $(filter %.o,$(obj-Y)),\ + printf "%s:" $(addprefix $(obj)/,$(mod-o)) >> $@; \ + printf " %s" $(sort $(strip $(addprefix $(obj)/,$($(mod-o:.o=-objs)) \ + $($(mod-o:.o=-y)) $($(mod-o:.o=-Y))))) >> $@; \ + printf "\n" >> $@; ) \ + cat /dev/null $(modthickbuiltin-subdirs) >> $@; + +PHONY += FORCE + +FORCE: + +# Descending +# --------------------------------------------------------------------------- + +PHONY += $(subdir-ym) +$(subdir-ym): + $(Q)$(MAKE) $(modbuiltin)=$@ builtin-file=$(builtin-file) + +.PHONY: $(PHONY) diff --git a/scripts/modules_thick.c b/scripts/modules_thick.c new file mode 100644 index 000000000000..9a15e99c1330 --- /dev/null +++ b/scripts/modules_thick.c @@ -0,0 +1,200 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * A simple modules_thick reader. + * + * (C) 2014, 2021 Oracle, Inc. All rights reserved. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + */ + +#include <errno.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> + +#include "modules_thick.h" + +/* + * Read a modules_thick.builtin file and translate it into a stream of + * name / module-name pairs. + */ + +/* + * Construct a modules_thick.builtin iterator. + */ +struct modules_thick_iter * +modules_thick_iter_new(const char *modules_thick_file) +{ + struct modules_thick_iter *i; + + i = calloc(1, sizeof(struct modules_thick_iter)); + if (i == NULL) + return NULL; + + i->f = fopen(modules_thick_file, "r"); + + if (i->f == NULL) { + fprintf(stderr, "Cannot open builtin module file %s: %s\n", + modules_thick_file, strerror(errno)); + return NULL; + } + + return i; +} + +/* + * Iterate, returning a new null-terminated array of object file names, and a + * new dynamically-allocated module name. (The module name passed in is freed.) + * + * The array of object file names should be freed by the caller: the strings it + * points to are owned by the iterator, and should not be freed. + */ + +char ** __attribute__((__nonnull__)) +modules_thick_iter_next(struct modules_thick_iter *i, char **module_name) +{ + size_t npaths = 1; + char **module_paths; + char *last_slash; + char *last_dot; + char *trailing_linefeed; + char *object_name = i->line; + char *dash; + int composite = 0; + + /* + * Read in all module entries, computing the suffixless, pathless name + * of the module and building the next arrayful of object file names for + * return. + * + * Modules can consist of multiple files: in this case, the portion + * before the colon is the path to the module (as before): the portion + * after the colon is a space-separated list of files that should be + * considered part of this module. In this case, the portion before the + * name is an "object file" that does not actually exist: it is merged + * into built-in.a without ever being written out. + * + * All module names have - translated to _, to match what is done to the + * names of the same things when built as modules. + */ + + /* + * Reinvocation of exhausted iterator. Return NULL, once. + */ +retry: + if (getline(&i->line, &i->line_size, i->f) < 0) { + if (ferror(i->f)) { + fprintf(stderr, "Error reading from modules_thick file:" + " %s\n", strerror(errno)); + exit(1); + } + rewind(i->f); + return NULL; + } + + if (i->line[0] == '\0') + goto retry; + + /* + * Slice the line in two at the colon, if any. If there is anything + * past the ': ', this is a composite module. (We allow for no colon + * for robustness, even though one should always be present.) + */ + if (strchr(i->line, ':') != NULL) { + char *name_start; + + object_name = strchr(i->line, ':'); + *object_name = '\0'; + object_name++; + name_start = object_name + strspn(object_name, " \n"); + if (*name_start != '\0') { + composite = 1; + object_name = name_start; + } + } + + /* + * Figure out the module name. + */ + last_slash = strrchr(i->line, '/'); + last_slash = (!last_slash) ? i->line : + last_slash + 1; + free(*module_name); + *module_name = strdup(last_slash); + dash = *module_name; + + while (dash != NULL) { + dash = strchr(dash, '-'); + if (dash != NULL) + *dash = '_'; + } + + last_dot = strrchr(*module_name, '.'); + if (last_dot != NULL) + *last_dot = '\0'; + + trailing_linefeed = strchr(object_name, '\n'); + if (trailing_linefeed != NULL) + *trailing_linefeed = '\0'; + + /* + * Multifile separator? Object file names explicitly stated: + * slice them up and shuffle them in. + * + * The array size may be an overestimate if any object file + * names start or end with spaces (very unlikely) but cannot be + * an underestimate. (Check for it anyway.) + */ + if (composite) { + char *one_object; + + for (npaths = 0, one_object = object_name; + one_object != NULL; + npaths++, one_object = strchr(one_object + 1, ' ')); + } + + module_paths = malloc((npaths + 1) * sizeof(char *)); + if (!module_paths) { + fprintf(stderr, "%s: out of memory on module %s\n", __func__, + *module_name); + exit(1); + } + + if (composite) { + char *one_object; + size_t i = 0; + + while ((one_object = strsep(&object_name, " ")) != NULL) { + if (i >= npaths) { + fprintf(stderr, "%s: num_objs overflow on module " + "%s: this is a bug.\n", __func__, + *module_name); + exit(1); + } + + module_paths[i++] = one_object; + } + } else + module_paths[0] = i->line; /* untransformed module name */ + + module_paths[npaths] = NULL; + + return module_paths; +} + +/* + * Free an iterator. Can be called while iteration is underway, so even + * state that is freed at the end of iteration must be freed here too. + */ +void +modules_thick_iter_free(struct modules_thick_iter *i) +{ + if (i == NULL) + return; + fclose(i->f); + free(i->line); + free(i); +} diff --git a/scripts/modules_thick.h b/scripts/modules_thick.h new file mode 100644 index 000000000000..f5edcaf9550c --- /dev/null +++ b/scripts/modules_thick.h @@ -0,0 +1,48 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * A simple modules_thick reader. + * + * (C) 2014, 2021 Oracle, Inc. All rights reserved. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + */ + +#ifndef _LINUX_MODULES_THICK_H +#define _LINUX_MODULES_THICK_H + +#include <stdio.h> +#include <stddef.h> + +/* + * modules_thick.builtin iteration state. + */ +struct modules_thick_iter { + FILE *f; + char *line; + size_t line_size; +}; + +/* + * Construct a modules_thick.builtin iterator. + */ +struct modules_thick_iter * +modules_thick_iter_new(const char *modules_thick_file); + +/* + * Iterate, returning a new null-terminated array of object file names, and a + * new dynamically-allocated module name. (The module name passed in is freed.) + * + * The array of object file names should be freed by the caller: the strings it + * points to are owned by the iterator, and should not be freed. + */ + +char ** __attribute__((__nonnull__)) +modules_thick_iter_next(struct modules_thick_iter *i, char **module_name); + +void +modules_thick_iter_free(struct modules_thick_iter *i); + +#endif