| Message ID | 20230805095709.6717-1-yoann.congal@smile.fr (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v2] kconfig: avoid an infinite loop in oldconfig/syncconfig | expand |
On Sat, Aug 5, 2023 at 6:57 PM Yoann Congal <yoann.congal@smile.fr> wrote: > > Exit on error when asking for value that has an invalid default value > and stdin has reached EOF. This happens in particular for hex/int > configs without an explicit default value. > > Previously, this case would loop: > * oldconfig prompts for the value but stdin has reached EOF > * It gets the global default value : an empty string > * This is not a valid hex/int value so it prompts again, hence the infinite loop. > > This case happens with a configuration like this (a hex config without a > valid default value): > config TEST_KCONFIG > hex "Test KConfig" > # default 0x0 > > And using: > make oldconfig < /dev/null > > This was discovered when working on Yocto bug[0] on a downstream > kconfig user (U-boot) > > [0]: https://bugzilla.yoctoproject.org/show_bug.cgi?id=14136 > > Signed-off-by: Yoann Congal <yoann.congal@smile.fr> > --- > v1->v2: > * Improve coding style > * Put more info in the commit message > > scripts/kconfig/conf.c | 10 +++++++++- > 1 file changed, 9 insertions(+), 1 deletion(-) > > diff --git a/scripts/kconfig/conf.c b/scripts/kconfig/conf.c > index 7cf63261d951c..8f32cbbce4805 100644 > --- a/scripts/kconfig/conf.c > +++ b/scripts/kconfig/conf.c > @@ -377,8 +377,16 @@ static int conf_string(struct menu *menu) > line[strlen(line)-1] = 0; > def = line; > } > - if (def && sym_set_string_value(sym, def)) > + if (def && sym_set_string_value(sym, def)) { > return 0; > + } else { > + if (feof(stdin) && !sym_string_valid(sym, sym_get_string_value(sym))) { > + fprintf(stderr, > + "Symbol %s has invalid default value and stdin reached EOF\n", > + sym->name); > + exit(1); > + } > + } > } > } > > -- > 2.30.2 > It is strange (and consistent) to bail out only for particular types. I would change the code simply as follows: --- a/scripts/kconfig/conf.c +++ b/scripts/kconfig/conf.c @@ -76,8 +76,10 @@ static void strip(char *str) /* Helper function to facilitate fgets() by Jean Sacren. */ static void xfgets(char *str, int size, FILE *in) { - if (!fgets(str, size, in)) + if (!fgets(str, size, in)) { fprintf(stderr, "\nError in reading or end of file.\n"); + exit(1); + } if (!tty_stdio) printf("%s", str); yes "" | make config will succeed. make config < /dev/null will fail. People expecting the closed stdin to succeed may start complaining, but I believe they must fix their wrong scripts.
On 8/7/23 12:25, Masahiro Yamada wrote: > On Sat, Aug 5, 2023 at 6:57 PM Yoann Congal <yoann.congal@smile.fr> wrote: >> >> Exit on error when asking for value that has an invalid default value >> and stdin has reached EOF. This happens in particular for hex/int >> configs without an explicit default value. >> >> Previously, this case would loop: >> * oldconfig prompts for the value but stdin has reached EOF >> * It gets the global default value : an empty string >> * This is not a valid hex/int value so it prompts again, hence the infinite loop. >> >> This case happens with a configuration like this (a hex config without a >> valid default value): >> config TEST_KCONFIG >> hex "Test KConfig" >> # default 0x0 >> >> And using: >> make oldconfig < /dev/null >> >> This was discovered when working on Yocto bug[0] on a downstream >> kconfig user (U-boot) >> >> [0]: https://bugzilla.yoctoproject.org/show_bug.cgi?id=14136 >> >> Signed-off-by: Yoann Congal <yoann.congal@smile.fr> >> --- >> v1->v2: >> * Improve coding style >> * Put more info in the commit message >> >> scripts/kconfig/conf.c | 10 +++++++++- >> 1 file changed, 9 insertions(+), 1 deletion(-) >> >> diff --git a/scripts/kconfig/conf.c b/scripts/kconfig/conf.c >> index 7cf63261d951c..8f32cbbce4805 100644 >> --- a/scripts/kconfig/conf.c >> +++ b/scripts/kconfig/conf.c >> @@ -377,8 +377,16 @@ static int conf_string(struct menu *menu) >> line[strlen(line)-1] = 0; >> def = line; >> } >> - if (def && sym_set_string_value(sym, def)) >> + if (def && sym_set_string_value(sym, def)) { >> return 0; >> + } else { >> + if (feof(stdin) && !sym_string_valid(sym, sym_get_string_value(sym))) { >> + fprintf(stderr, >> + "Symbol %s has invalid default value and stdin reached EOF\n", >> + sym->name); >> + exit(1); >> + } >> + } >> } >> } >> >> -- >> 2.30.2 >> > > > It is strange (and consistent) to bail out > only for particular types. > It's still very helpful to know the symbol name that is causing the issue. > > I would change the code simply as follows: > > > > --- a/scripts/kconfig/conf.c > +++ b/scripts/kconfig/conf.c > @@ -76,8 +76,10 @@ static void strip(char *str) > /* Helper function to facilitate fgets() by Jean Sacren. */ > static void xfgets(char *str, int size, FILE *in) > { > - if (!fgets(str, size, in)) > + if (!fgets(str, size, in)) { > fprintf(stderr, "\nError in reading or end of file.\n"); > + exit(1); > + } > > if (!tty_stdio) > printf("%s", str); > > > > > > > yes "" | make config > > will succeed. > > > > make config < /dev/null > > will fail. > > > > > > People expecting the closed stdin to succeed > may start complaining, but I believe > they must fix their wrong scripts. > >
Hi, On 8/7/23 22:25, Randy Dunlap wrote: > On 8/7/23 12:25, Masahiro Yamada wrote: >> It is strange (and consistent) to bail out >> only for particular types. > > It's still very helpful to know the symbol name that is causing > the issue. > >> >> I would change the code simply as follows: >> *snip*>> >> yes "" | make config >> >> will succeed. >> >> make config < /dev/null >> >> will fail. >> >> People expecting the closed stdin to succeed >> may start complaining, but I believe >> they must fix their wrong scripts. I've sent a v3 trying to fuse both of your suggestions. Regards,
diff --git a/scripts/kconfig/conf.c b/scripts/kconfig/conf.c index 7cf63261d951c..8f32cbbce4805 100644 --- a/scripts/kconfig/conf.c +++ b/scripts/kconfig/conf.c @@ -377,8 +377,16 @@ static int conf_string(struct menu *menu) line[strlen(line)-1] = 0; def = line; } - if (def && sym_set_string_value(sym, def)) + if (def && sym_set_string_value(sym, def)) { return 0; + } else { + if (feof(stdin) && !sym_string_valid(sym, sym_get_string_value(sym))) { + fprintf(stderr, + "Symbol %s has invalid default value and stdin reached EOF\n", + sym->name); + exit(1); + } + } } }
Exit on error when asking for value that has an invalid default value and stdin has reached EOF. This happens in particular for hex/int configs without an explicit default value. Previously, this case would loop: * oldconfig prompts for the value but stdin has reached EOF * It gets the global default value : an empty string * This is not a valid hex/int value so it prompts again, hence the infinite loop. This case happens with a configuration like this (a hex config without a valid default value): config TEST_KCONFIG hex "Test KConfig" # default 0x0 And using: make oldconfig < /dev/null This was discovered when working on Yocto bug[0] on a downstream kconfig user (U-boot) [0]: https://bugzilla.yoctoproject.org/show_bug.cgi?id=14136 Signed-off-by: Yoann Congal <yoann.congal@smile.fr> --- v1->v2: * Improve coding style * Put more info in the commit message scripts/kconfig/conf.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-)