On Fri, Oct 1, 2021 at 2:33 PM Masahiro Yamada <masahiroy@xxxxxxxxxx> wrote:
>
> sym_escape_string_value() returns a malloc'ed memory, but as
> (const char *). So, it must be casted to (void *) when it is free'd.
> This is odd.
>
> The return type of sym_escape_string_value() should be (char *).
>
> I exploited that free(NULL) has no effect.
>
> Signed-off-by: Masahiro Yamada <masahiroy@xxxxxxxxxx>
> ---
All applied to linux-kbuild.
I pushed 10/10 v3 to the for-next branch.
>
> scripts/kconfig/conf.c | 15 +++++++--------
> scripts/kconfig/confdata.c | 27 ++++++++++++++-------------
> scripts/kconfig/lkc_proto.h | 2 +-
> scripts/kconfig/symbol.c | 3 ++-
> 4 files changed, 24 insertions(+), 23 deletions(-)
>
> diff --git a/scripts/kconfig/conf.c b/scripts/kconfig/conf.c
> index 5d84b44a2a2a..310fdd408793 100644
> --- a/scripts/kconfig/conf.c
> +++ b/scripts/kconfig/conf.c
> @@ -647,17 +647,16 @@ static void check_conf(struct menu *menu)
> switch (input_mode) {
> case listnewconfig:
> if (sym->name) {
> - const char *str;
> + const char *val = sym_get_string_value(sym);
> + char *escaped = NULL;
>
> if (sym->type == S_STRING) {
> - str = sym_get_string_value(sym);
> - str = sym_escape_string_value(str);
> - printf("%s%s=%s\n", CONFIG_, sym->name, str);
> - free((void *)str);
> - } else {
> - str = sym_get_string_value(sym);
> - printf("%s%s=%s\n", CONFIG_, sym->name, str);
> + escaped = sym_escape_string_value(val);
> + val = escaped;
> }
> +
> + printf("%s%s=%s\n", CONFIG_, sym->name, val);
> + free(escaped);
> }
> break;
> case helpnewconfig:
> diff --git a/scripts/kconfig/confdata.c b/scripts/kconfig/confdata.c
> index cf72680cd769..9b2271eb43d6 100644
> --- a/scripts/kconfig/confdata.c
> +++ b/scripts/kconfig/confdata.c
> @@ -728,21 +728,22 @@ static struct conf_printer header_printer_cb =
> static void conf_write_symbol(FILE *fp, struct symbol *sym,
> struct conf_printer *printer, void *printer_arg)
> {
> - const char *str;
> + const char *val;
> + char *escaped = NULL;
>
> - switch (sym->type) {
> - case S_UNKNOWN:
> - break;
> - case S_STRING:
> - str = sym_get_string_value(sym);
> - str = sym_escape_string_value(str);
> - printer->print_symbol(fp, sym, str, printer_arg);
> - free((void *)str);
> - break;
> - default:
> - str = sym_get_string_value(sym);
> - printer->print_symbol(fp, sym, str, printer_arg);
> + if (sym->type == S_UNKNOWN)
> + return;
> +
> + val = sym_get_string_value(sym);
> +
> + if (sym->type == S_STRING) {
> + escaped = sym_escape_string_value(val);
> + val = escaped;
> }
> +
> + printer->print_symbol(fp, sym, val, printer_arg);
> +
> + free(escaped);
> }
>
> static void
> diff --git a/scripts/kconfig/lkc_proto.h b/scripts/kconfig/lkc_proto.h
> index a11626bdc421..e6955df49973 100644
> --- a/scripts/kconfig/lkc_proto.h
> +++ b/scripts/kconfig/lkc_proto.h
> @@ -18,7 +18,7 @@ extern struct symbol * symbol_hash[SYMBOL_HASHSIZE];
>
> struct symbol * sym_lookup(const char *name, int flags);
> struct symbol * sym_find(const char *name);
> -const char * sym_escape_string_value(const char *in);
> +char *sym_escape_string_value(const char *in);
> struct symbol ** sym_re_search(const char *pattern);
> const char * sym_type_name(enum symbol_type type);
> void sym_calc_value(struct symbol *sym);
> diff --git a/scripts/kconfig/symbol.c b/scripts/kconfig/symbol.c
> index 5844d636d38f..6bf8665a6a0f 100644
> --- a/scripts/kconfig/symbol.c
> +++ b/scripts/kconfig/symbol.c
> @@ -871,7 +871,8 @@ struct symbol *sym_find(const char *name)
> return symbol;
> }
>
> -const char *sym_escape_string_value(const char *in)
> +/* The returned pointer must be freed on the caller side */
> +char *sym_escape_string_value(const char *in)
> {
> const char *p;
> size_t reslen;
> --
> 2.30.2
>
--
Best Regards
Masahiro Yamada
