Re: [PATCH 06/27] modpost: use bool type where appropriate

From: Masahiro Yamada
Date: Sun May 01 2022 - 09:16:23 EST


On Tue, Apr 26, 2022 at 3:34 AM Nick Desaulniers
<ndesaulniers@xxxxxxxxxx> wrote:
>
> /On Sun, Apr 24, 2022 at 12:09 PM Masahiro Yamada <masahiroy@xxxxxxxxxx> wrote:
> >
> > Use 'bool' to clarify that the valid value is true or false.
> >
> > Here is a small note for the conversion.
> >
> > Strictly speaking, module::gpl_compatible was not boolean because
> > new_module() initialized it to -1. Maybe, -1 was used to represent the
> > license is 'unknown', but it is not useful.
> >
> > Since commit 1d6cd3929360 ("modpost: turn missing MODULE_LICENSE() into
> > error"), unknown module license is not allowed anyway.
> >
> > I changed the initializer "= -1" to "= true". This has no functional
> > change.
> >
> > The current code:
> >
> > if (!mod->gpl_compatible)
> > check_for_gpl_usage(exp->export, basename, exp->name);
> >
> > ... only checks whether gpl_compabilt is zero or not:
>
> s/gpl_compabilt/gpl_compatible/
>
> Also the trailing `:` should perhaps be `.`.
>
> Shouldn't gpl_compatible default to false, until proven otherwise?
> What happens if you default to false? Perhaps an identifier like
> `maybe_gpl_compatible` would be more descriptive?


The init value should be 'true'.

In v2, I split this change into a separate patch,
and added some comments.

https://patchwork.kernel.org/project/linux-kbuild/patch/20220501084032.1025918-3-masahiroy@xxxxxxxxxx/

I hope it answered your question.




> Also, if we're going to rename a few vars, consider using prefixes
> like is_*, has_*, or should_* for some of these to improve the
> readability for boolean variables.


OK, I renamed it to is_gpl_compatible in v2.






> Otherwise LGTM.
>
> >
> > Signed-off-by: Masahiro Yamada <masahiroy@xxxxxxxxxx>
> > ---
> >
> > scripts/mod/modpost.c | 60 +++++++++++++++++++++----------------------
> > scripts/mod/modpost.h | 10 ++++----
> > 2 files changed, 35 insertions(+), 35 deletions(-)
> >
> > diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
> > index f9cbb6b6b7a5..52dd07a36379 100644
> > --- a/scripts/mod/modpost.c
> > +++ b/scripts/mod/modpost.c
> > @@ -23,20 +23,20 @@
> > #include "../../include/linux/license.h"
> >
> > /* Are we using CONFIG_MODVERSIONS? */
> > -static int modversions;
> > +static bool modversions;
> > /* Is CONFIG_MODULE_SRCVERSION_ALL set? */
> > -static int all_versions;
> > +static bool all_versions;
> > /* If we are modposting external module set to 1 */
> > -static int external_module;
> > +static bool external_module;
> > /* Only warn about unresolved symbols */
> > -static int warn_unresolved;
> > +static bool warn_unresolved;
> > /* How a symbol is exported */
> > static int sec_mismatch_count;
> > -static int sec_mismatch_warn_only = true;
> > +static bool sec_mismatch_warn_only = true;
> > /* ignore missing files */
> > -static int ignore_missing_files;
> > +static bool ignore_missing_files;
> > /* If set to 1, only warn (instead of error) about missing ns imports */
> > -static int allow_missing_ns_imports;
> > +static bool allow_missing_ns_imports;
> >
> > static bool error_occurred;
> >
> > @@ -187,7 +187,7 @@ static struct module *new_module(const char *modname)
> > /* add to list */
> > strcpy(mod->name, modname);
> > mod->is_vmlinux = (strcmp(modname, "vmlinux") == 0);
> > - mod->gpl_compatible = -1;
> > + mod->gpl_compatible = true;
> > mod->next = modules;
> > modules = mod;
> >
> > @@ -203,10 +203,10 @@ struct symbol {
> > struct symbol *next;
> > struct module *module;
> > unsigned int crc;
> > - int crc_valid;
> > + bool crc_valid;
> > char *namespace;
> > - unsigned int weak:1;
> > - unsigned int is_static:1; /* 1 if symbol is not global */
> > + bool weak;
> > + bool is_static; /* true if symbol is not global */
> > enum export export; /* Type of export */
> > char name[];
> > };
> > @@ -230,7 +230,7 @@ static inline unsigned int tdb_hash(const char *name)
> > * Allocate a new symbols for use in the hash of exported symbols or
> > * the list of unresolved symbols per module
> > **/
> > -static struct symbol *alloc_symbol(const char *name, unsigned int weak,
> > +static struct symbol *alloc_symbol(const char *name, bool weak,
> > struct symbol *next)
> > {
> > struct symbol *s = NOFAIL(malloc(sizeof(*s) + strlen(name) + 1));
> > @@ -239,7 +239,7 @@ static struct symbol *alloc_symbol(const char *name, unsigned int weak,
> > strcpy(s->name, name);
> > s->weak = weak;
> > s->next = next;
> > - s->is_static = 1;
> > + s->is_static = true;
> > return s;
> > }
> >
> > @@ -250,7 +250,7 @@ static struct symbol *new_symbol(const char *name, struct module *module,
> > unsigned int hash;
> >
> > hash = tdb_hash(name) % SYMBOL_HASH_SIZE;
> > - symbolhash[hash] = alloc_symbol(name, 0, symbolhash[hash]);
> > + symbolhash[hash] = alloc_symbol(name, false, symbolhash[hash]);
> >
> > return symbolhash[hash];
> > }
> > @@ -419,7 +419,7 @@ static void sym_set_crc(const char *name, unsigned int crc)
> > return;
> >
> > s->crc = crc;
> > - s->crc_valid = 1;
> > + s->crc_valid = true;
> > }
> >
> > static void *grab_file(const char *filename, size_t *size)
> > @@ -716,9 +716,9 @@ static void handle_symbol(struct module *mod, struct elf_info *info,
> > sym_add_exported(name, mod, export);
> > }
> > if (strcmp(symname, "init_module") == 0)
> > - mod->has_init = 1;
> > + mod->has_init = true;
> > if (strcmp(symname, "cleanup_module") == 0)
> > - mod->has_cleanup = 1;
> > + mod->has_cleanup = true;
> > break;
> > }
> > }
> > @@ -2008,9 +2008,9 @@ static void read_symbols(const char *modname)
> > error("missing MODULE_LICENSE() in %s\n", modname);
> > while (license) {
> > if (license_is_gpl_compatible(license))
> > - mod->gpl_compatible = 1;
> > + mod->gpl_compatible = true;
> > else {
> > - mod->gpl_compatible = 0;
> > + mod->gpl_compatible = false;
> > break;
> > }
> > license = get_next_modinfo(&info, "license", license);
> > @@ -2053,7 +2053,7 @@ static void read_symbols(const char *modname)
> > sym->st_name));
> >
> > if (s)
> > - s->is_static = 0;
> > + s->is_static = false;
> > }
> > }
> >
> > @@ -2073,7 +2073,7 @@ static void read_symbols(const char *modname)
> > * the automatic versioning doesn't pick it up, but it's really
> > * important anyhow */
> > if (modversions)
> > - mod->unres = alloc_symbol("module_layout", 0, mod->unres);
> > + mod->unres = alloc_symbol("module_layout", false, mod->unres);
> > }
> >
> > static void read_symbols_from_files(const char *filename)
> > @@ -2305,7 +2305,7 @@ static void add_depends(struct buffer *b, struct module *mod)
> > if (s->module->seen)
> > continue;
> >
> > - s->module->seen = 1;
> > + s->module->seen = true;
> > p = strrchr(s->module->name, '/');
> > if (p)
> > p++;
> > @@ -2422,10 +2422,10 @@ static void read_dump(const char *fname)
> > mod = find_module(modname);
> > if (!mod) {
> > mod = new_module(modname);
> > - mod->from_dump = 1;
> > + mod->from_dump = true;
> > }
> > s = sym_add_exported(symname, mod, export_no(export));
> > - s->is_static = 0;
> > + s->is_static = false;
> > sym_set_crc(symname, crc);
> > sym_update_namespace(symname, namespace);
> > }
> > @@ -2503,7 +2503,7 @@ int main(int argc, char **argv)
> > while ((opt = getopt(argc, argv, "ei:mnT:o:awENd:")) != -1) {
> > switch (opt) {
> > case 'e':
> > - external_module = 1;
> > + external_module = true;
> > break;
> > case 'i':
> > *dump_read_iter =
> > @@ -2512,28 +2512,28 @@ int main(int argc, char **argv)
> > dump_read_iter = &(*dump_read_iter)->next;
> > break;
> > case 'm':
> > - modversions = 1;
> > + modversions = true;
> > break;
> > case 'n':
> > - ignore_missing_files = 1;
> > + ignore_missing_files = true;
> > break;
> > case 'o':
> > dump_write = optarg;
> > break;
> > case 'a':
> > - all_versions = 1;
> > + all_versions = true;
> > break;
> > case 'T':
> > files_source = optarg;
> > break;
> > case 'w':
> > - warn_unresolved = 1;
> > + warn_unresolved = true;
> > break;
> > case 'E':
> > sec_mismatch_warn_only = false;
> > break;
> > case 'N':
> > - allow_missing_ns_imports = 1;
> > + allow_missing_ns_imports = true;
> > break;
> > case 'd':
> > missing_namespace_deps = optarg;
> > diff --git a/scripts/mod/modpost.h b/scripts/mod/modpost.h
> > index a85dcec3669a..4085bf5b33aa 100644
> > --- a/scripts/mod/modpost.h
> > +++ b/scripts/mod/modpost.h
> > @@ -1,4 +1,5 @@
> > /* SPDX-License-Identifier: GPL-2.0 */
> > +#include <stdbool.h>
> > #include <stdio.h>
> > #include <stdlib.h>
> > #include <stdarg.h>
> > @@ -116,11 +117,10 @@ struct module {
> > struct module *next;
> > int gpl_compatible;
> > struct symbol *unres;
> > - int from_dump; /* 1 if module was loaded from *.symvers */
> > - int is_vmlinux;
> > - int seen;
> > - int has_init;
> > - int has_cleanup;
> > + bool from_dump; /* true if module was loaded from *.symvers */
> > + bool is_vmlinux;
> > + bool seen;
> > + bool has_init, has_cleanup;
> > struct buffer dev_table_buf;
> > char srcversion[25];
> > // Missing namespace dependencies
> > --
> > 2.32.0
> >
>
>
> --
> Thanks,
> ~Nick Desaulniers



--
Best Regards
Masahiro Yamada