| Message ID | 20180712111221.20326-10-armbru@redhat.com |
|---|---|
| State | New |
| Headers | show |
| Series | tests: Compile-time format string checking for libqtest.h | expand |
On 07/12/2018 08:12 AM, Markus Armbruster wrote: > qobject_from_jsonv() takes ownership of %p arguments. On failure, we > can't generally know whether we failed before or after %p, so > ownership becomes indeterminate. To avoid leaks, callers passing %p > must terminate on error, e.g. by passing &error_abort. Trap for the > unwary; document and give the function internal linkage. > > Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org> > --- > include/qapi/qmp/qjson.h | 2 -- > qobject/qjson.c | 13 ++++++++++++- > 2 files changed, 12 insertions(+), 3 deletions(-) > > diff --git a/include/qapi/qmp/qjson.h b/include/qapi/qmp/qjson.h > index 0db121bef9..4a225cf7d1 100644 > --- a/include/qapi/qmp/qjson.h > +++ b/include/qapi/qmp/qjson.h > @@ -15,8 +15,6 @@ > #define QJSON_H > > QObject *qobject_from_json(const char *string, Error **errp); > -QObject *qobject_from_jsonv(const char *string, va_list *ap, Error **errp) > - GCC_FMT_ATTR(1, 0); > > QObject *qobject_from_vjsonf_nofail(const char *string, va_list) > GCC_FMT_ATTR(1, 0); > diff --git a/qobject/qjson.c b/qobject/qjson.c > index 2e450231ff..ab4040f235 100644 > --- a/qobject/qjson.c > +++ b/qobject/qjson.c > @@ -39,7 +39,18 @@ static void parse_json(JSONMessageParser *parser, GQueue *tokens) > s->result = json_parser_parse_err(tokens, s->ap, &s->err); > } > > -QObject *qobject_from_jsonv(const char *string, va_list *ap, Error **errp) > +/* > + * Parse @string as JSON value. > + * If @ap is non-null, interpolate %-escapes. > + * Takes ownership of %p arguments. > + * On success, return the JSON value. > + * On failure, store an error through @errp and return NULL. > + * Ownership of %p arguments becomes indeterminate then. To avoid > + * leaks, callers passing %p must terminate on error, e.g. by passing > + * &error_abort. > + */ > +static QObject *qobject_from_jsonv(const char *string, va_list *ap, > + Error **errp) > { > JSONParsingState state = {}; > >
diff --git a/include/qapi/qmp/qjson.h b/include/qapi/qmp/qjson.h index 0db121bef9..4a225cf7d1 100644 --- a/include/qapi/qmp/qjson.h +++ b/include/qapi/qmp/qjson.h @@ -15,8 +15,6 @@ #define QJSON_H QObject *qobject_from_json(const char *string, Error **errp); -QObject *qobject_from_jsonv(const char *string, va_list *ap, Error **errp) - GCC_FMT_ATTR(1, 0); QObject *qobject_from_vjsonf_nofail(const char *string, va_list) GCC_FMT_ATTR(1, 0); diff --git a/qobject/qjson.c b/qobject/qjson.c index 2e450231ff..ab4040f235 100644 --- a/qobject/qjson.c +++ b/qobject/qjson.c @@ -39,7 +39,18 @@ static void parse_json(JSONMessageParser *parser, GQueue *tokens) s->result = json_parser_parse_err(tokens, s->ap, &s->err); } -QObject *qobject_from_jsonv(const char *string, va_list *ap, Error **errp) +/* + * Parse @string as JSON value. + * If @ap is non-null, interpolate %-escapes. + * Takes ownership of %p arguments. + * On success, return the JSON value. + * On failure, store an error through @errp and return NULL. + * Ownership of %p arguments becomes indeterminate then. To avoid + * leaks, callers passing %p must terminate on error, e.g. by passing + * &error_abort. + */ +static QObject *qobject_from_jsonv(const char *string, va_list *ap, + Error **errp) { JSONParsingState state = {};
qobject_from_jsonv() takes ownership of %p arguments. On failure, we can't generally know whether we failed before or after %p, so ownership becomes indeterminate. To avoid leaks, callers passing %p must terminate on error, e.g. by passing &error_abort. Trap for the unwary; document and give the function internal linkage. Signed-off-by: Markus Armbruster <armbru@redhat.com> --- include/qapi/qmp/qjson.h | 2 -- qobject/qjson.c | 13 ++++++++++++- 2 files changed, 12 insertions(+), 3 deletions(-)