| Message ID | 20220622152421.989555-1-goldstein.w.n@gmail.com |
|---|---|
| State | New |
| Headers | show |
| Series | [v2] stdlib: Remove attr_write from mbstows if dst is NULL [BZ: 29265] | expand |
On 22/06/2022 20:54, Noah Goldstein via Libc-alpha wrote: > mbstows is defined if dst is NULL and is defined to special cased if > dst is NULL so the fortify objsize check if incorrect in that case. > > Tested on x86-64 linux. > --- > stdlib/Makefile | 3 +++ > stdlib/bits/stdlib.h | 16 +++++++++++----- > stdlib/testmb.c | 7 +++++++ > 3 files changed, 21 insertions(+), 5 deletions(-) LGTM. Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org> > > diff --git a/stdlib/Makefile b/stdlib/Makefile > index 60fc59c12c..6ef725ef74 100644 > --- a/stdlib/Makefile > +++ b/stdlib/Makefile > @@ -373,6 +373,9 @@ CFLAGS-tst-qsort.c += $(stack-align-test-flags) > CFLAGS-tst-makecontext.c += -funwind-tables > CFLAGS-tst-makecontext2.c += $(stack-align-test-flags) > > +CFLAGS-testmb.c += -D_FORTIFY_SOURCE=2 -Wall -Werror > + > + > # Run a test on the header files we use. > tests-special += $(objpfx)isomac.out > > diff --git a/stdlib/bits/stdlib.h b/stdlib/bits/stdlib.h > index 277d099e22..d9c2d822a5 100644 > --- a/stdlib/bits/stdlib.h > +++ b/stdlib/bits/stdlib.h > @@ -96,6 +96,11 @@ extern size_t __mbstowcs_chk (wchar_t *__restrict __dst, > const char *__restrict __src, > size_t __len, size_t __dstlen) __THROW > __attr_access ((__write_only__, 1, 3)) __attr_access ((__read_only__, 2)); > +extern size_t __REDIRECT_NTH (__mbstowcs_chk_nulldst, > + (wchar_t *__restrict __dst, > + const char *__restrict __src, > + size_t __len), mbstowcs_chk) > + __attr_access ((__read_only__, 2)); > extern size_t __REDIRECT_NTH (__mbstowcs_alias, > (wchar_t *__restrict __dst, > const char *__restrict __src, > @@ -108,16 +113,17 @@ extern size_t __REDIRECT_NTH (__mbstowcs_chk_warn, > __warnattr ("mbstowcs called with dst buffer smaller than len " > "* sizeof (wchar_t)"); > > -__fortify_function size_t > +__always_inline __fortify_function size_t > __NTH (mbstowcs (wchar_t *__restrict __dst, const char *__restrict __src, > size_t __len)) > { > - return __glibc_fortify_n (mbstowcs, __len, sizeof (wchar_t), > - __glibc_objsize (__dst), > - __dst, __src, __len); > + if (__builtin_constant_p (__dst == NULL) && __dst == NULL) > + return __mbstowcs_chk_nulldst (__dst, __src, __len); > + else > + return __glibc_fortify_n (mbstowcs, __len, sizeof (wchar_t), > + __glibc_objsize (__dst), __dst, __src, __len); > } > > - > extern size_t __wcstombs_chk (char *__restrict __dst, > const wchar_t *__restrict __src, > size_t __len, size_t __dstlen) __THROW > diff --git a/stdlib/testmb.c b/stdlib/testmb.c > index 45dae7db61..6ac4dfd21d 100644 > --- a/stdlib/testmb.c > +++ b/stdlib/testmb.c > @@ -16,6 +16,13 @@ main (int argc, char *argv[]) > lose = 1; > } > > + i = mbstowcs (NULL, "bar", 4); > + if (!(i == 3 && w[1] == 'a')) > + { > + puts ("mbstowcs FAILED2!"); > + lose = 1; > + } > + > mbstowcs (w, "blah", 5); > i = wcstombs (c, w, 10); > if (i != 4)
diff --git a/stdlib/Makefile b/stdlib/Makefile index 60fc59c12c..6ef725ef74 100644 --- a/stdlib/Makefile +++ b/stdlib/Makefile @@ -373,6 +373,9 @@ CFLAGS-tst-qsort.c += $(stack-align-test-flags) CFLAGS-tst-makecontext.c += -funwind-tables CFLAGS-tst-makecontext2.c += $(stack-align-test-flags) +CFLAGS-testmb.c += -D_FORTIFY_SOURCE=2 -Wall -Werror + + # Run a test on the header files we use. tests-special += $(objpfx)isomac.out diff --git a/stdlib/bits/stdlib.h b/stdlib/bits/stdlib.h index 277d099e22..d9c2d822a5 100644 --- a/stdlib/bits/stdlib.h +++ b/stdlib/bits/stdlib.h @@ -96,6 +96,11 @@ extern size_t __mbstowcs_chk (wchar_t *__restrict __dst, const char *__restrict __src, size_t __len, size_t __dstlen) __THROW __attr_access ((__write_only__, 1, 3)) __attr_access ((__read_only__, 2)); +extern size_t __REDIRECT_NTH (__mbstowcs_chk_nulldst, + (wchar_t *__restrict __dst, + const char *__restrict __src, + size_t __len), mbstowcs_chk) + __attr_access ((__read_only__, 2)); extern size_t __REDIRECT_NTH (__mbstowcs_alias, (wchar_t *__restrict __dst, const char *__restrict __src, @@ -108,16 +113,17 @@ extern size_t __REDIRECT_NTH (__mbstowcs_chk_warn, __warnattr ("mbstowcs called with dst buffer smaller than len " "* sizeof (wchar_t)"); -__fortify_function size_t +__always_inline __fortify_function size_t __NTH (mbstowcs (wchar_t *__restrict __dst, const char *__restrict __src, size_t __len)) { - return __glibc_fortify_n (mbstowcs, __len, sizeof (wchar_t), - __glibc_objsize (__dst), - __dst, __src, __len); + if (__builtin_constant_p (__dst == NULL) && __dst == NULL) + return __mbstowcs_chk_nulldst (__dst, __src, __len); + else + return __glibc_fortify_n (mbstowcs, __len, sizeof (wchar_t), + __glibc_objsize (__dst), __dst, __src, __len); } - extern size_t __wcstombs_chk (char *__restrict __dst, const wchar_t *__restrict __src, size_t __len, size_t __dstlen) __THROW diff --git a/stdlib/testmb.c b/stdlib/testmb.c index 45dae7db61..6ac4dfd21d 100644 --- a/stdlib/testmb.c +++ b/stdlib/testmb.c @@ -16,6 +16,13 @@ main (int argc, char *argv[]) lose = 1; } + i = mbstowcs (NULL, "bar", 4); + if (!(i == 3 && w[1] == 'a')) + { + puts ("mbstowcs FAILED2!"); + lose = 1; + } + mbstowcs (w, "blah", 5); i = wcstombs (c, w, 10); if (i != 4)