[PATCH 01/10] kconfig: remove 'const' from the return type of sym_escape_string_value()

From: Masahiro Yamada
Date: Fri Oct 01 2021 - 01:33:47 EST


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>
---

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