From: Aurelien Jarno <aurelien@aurel32.net>
To: libc-stable@sourceware.org
Cc: Noah Goldstein <goldstein.w.n@gmail.com>,
Siddhesh Poyarekar <siddhesh@sourceware.org>
Subject: [COMMITTED 2.34 1/2] stdlib: Remove attr_write from mbstows if dst is NULL [BZ: 29265]
Date: Tue, 16 Aug 2022 00:17:07 +0200 [thread overview]
Message-ID: <20220815221707.2475899-1-aurelien@aurel32.net> (raw)
From: Noah Goldstein <goldstein.w.n@gmail.com>
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.
Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
(cherry picked from commit 464d189b9622932a75302290625de84931656ec0)
---
stdlib/Makefile | 3 +++
stdlib/bits/stdlib.h | 16 +++++++++++-----
stdlib/testmb.c | 7 +++++++
3 files changed, 21 insertions(+), 5 deletions(-)
diff --git a/stdlib/Makefile b/stdlib/Makefile
index a4ac30d1f6..e13f1ee33c 100644
--- a/stdlib/Makefile
+++ b/stdlib/Makefile
@@ -217,6 +217,9 @@ 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 ccacbdf76a..f0918d5d79 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)
--
2.35.1
next reply other threads:[~2022-08-15 22:17 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-08-15 22:17 Aurelien Jarno [this message]
2022-08-15 22:17 ` [COMMITTED 2.34 2/2] stdlib: Fixup mbstowcs NULL __dst handling. [BZ #29279] Aurelien Jarno
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