On Tue, Feb 12, 2013 at 05:28:53PM +0400, Evgeniy Stepanov wrote: > Hey, > > seems like that last of the scanf changes are in. > We're intercepting __isoc99_*scanf irrespective of the glibc version, > because (a) it does not hurt (and with the static runtime, even > interceptor itself is thrown out by the linker), and (b) user program > and tool's runtime can be built with different libc versions. > > Thanks for the help with scanf testing, we've got much more confidence > in our implementation now.
Thanks. Perhaps (completely untested) you could still disallow the GNU %as/%aS/%a[ compatibility for __isoc99_*, that way you can acurately verify even #define _XOPEN_SOURCE 700 ... float flt; int i; sscanf ("0.1234[x6]", "%a[x%d]", &flt, &i); --- sanitizer_common/sanitizer_common_interceptors.inc.jj 2013-02-12 14:34:06.000000000 +0100 +++ sanitizer_common/sanitizer_common_interceptors.inc 2013-02-12 14:40:05.486968072 +0100 @@ -150,7 +150,7 @@ INTERCEPTOR(int, prctl, int option, unsi #include "sanitizer_common_interceptors_scanf.inc" -#define VSCANF_INTERCEPTOR_IMPL(vname, ...) \ +#define VSCANF_INTERCEPTOR_IMPL(vname, allowGnuMalloc, ...) \ { \ void *ctx; \ COMMON_INTERCEPTOR_ENTER(ctx, vname, __VA_ARGS__); \ @@ -158,29 +158,29 @@ INTERCEPTOR(int, prctl, int option, unsi va_copy(aq, ap); \ int res = REAL(vname)(__VA_ARGS__); \ if (res > 0) \ - scanf_common(ctx, res, format, aq); \ + scanf_common(ctx, res, allowGnuMalloc, format, aq); \ va_end(aq); \ return res; \ } INTERCEPTOR(int, vscanf, const char *format, va_list ap) -VSCANF_INTERCEPTOR_IMPL(vscanf, format, ap) +VSCANF_INTERCEPTOR_IMPL(vscanf, true, format, ap) INTERCEPTOR(int, vsscanf, const char *str, const char *format, va_list ap) -VSCANF_INTERCEPTOR_IMPL(vsscanf, str, format, ap) +VSCANF_INTERCEPTOR_IMPL(vsscanf, true, str, format, ap) INTERCEPTOR(int, vfscanf, void *stream, const char *format, va_list ap) -VSCANF_INTERCEPTOR_IMPL(vfscanf, stream, format, ap) +VSCANF_INTERCEPTOR_IMPL(vfscanf, true, stream, format, ap) INTERCEPTOR(int, __isoc99_vscanf, const char *format, va_list ap) -VSCANF_INTERCEPTOR_IMPL(__isoc99_vscanf, format, ap) +VSCANF_INTERCEPTOR_IMPL(__isoc99_vscanf, false, format, ap) INTERCEPTOR(int, __isoc99_vsscanf, const char *str, const char *format, va_list ap) -VSCANF_INTERCEPTOR_IMPL(__isoc99_vsscanf, str, format, ap) +VSCANF_INTERCEPTOR_IMPL(__isoc99_vsscanf, false, str, format, ap) INTERCEPTOR(int, __isoc99_vfscanf, void *stream, const char *format, va_list ap) -VSCANF_INTERCEPTOR_IMPL(__isoc99_vfscanf, stream, format, ap) +VSCANF_INTERCEPTOR_IMPL(__isoc99_vfscanf, false, stream, format, ap) #define SCANF_INTERCEPTOR_IMPL(name, vname, ...) \ { \ --- sanitizer_common/sanitizer_common_interceptors_scanf.inc.jj 2013-02-11 16:56:09.000000000 +0100 +++ sanitizer_common/sanitizer_common_interceptors_scanf.inc 2013-02-12 14:37:46.948784135 +0100 @@ -39,7 +39,8 @@ static bool char_is_one_of(char c, const // returned in dir. This function returns the pointer to the first // unprocessed character, or 0 in case of error. // In case of the end-of-string, a pointer to the closing \0 is returned. -static const char *scanf_parse_next(const char *p, ScanfDirective *dir) { +static const char *scanf_parse_next(const char *p, bool allowGnuMalloc, + ScanfDirective *dir) { internal_memset(dir, 0, sizeof(*dir)); dir->argIdx = -1; @@ -121,7 +122,8 @@ static const char *scanf_parse_next(cons // This is unfortunately ambiguous between old GNU extension // of %as, %aS and %a[...] and newer POSIX %a followed by // letters s, S or [. - if (dir->convSpecifier == 'a' && !dir->lengthModifier[0]) { + if (dir->convSpecifier == 'a' && !dir->lengthModifier[0] + && allowGnuMalloc) { if (*p == 's' || *p == 'S') { dir->maybeGnuMalloc = true; ++p; @@ -271,14 +273,14 @@ static int scanf_get_store_size(ScanfDir // Common part of *scanf interceptors. // Process format string and va_list, and report all store ranges. // Stops when "consuming" n_inputs input items. -static void scanf_common(void *ctx, int n_inputs, const char *format, - va_list aq) { +static void scanf_common(void *ctx, int n_inputs, bool allowGnuMalloc, + const char *format, va_list aq) { CHECK_GT(n_inputs, 0); const char *p = format; while (*p && n_inputs) { ScanfDirective dir; - p = scanf_parse_next(p, &dir); + p = scanf_parse_next(p, allowGnuMalloc, &dir); if (!p) break; if (dir.convSpecifier == 0) { Jakub