Compilers may not be able to apply asm redirections to functions after
these functions are used for the first time, e.g. clang 13.
Fix [BZ #27087] by applying all long double-related asm redirections
before using functions in bits/stdio.h.
However, as these asm redirections depend on the declarations provided
by libio/bits/stdio2.h, this header was split in 2:
- libio/bits/stdio2-decl.h contains all function declarations;
- libio/bits/stdio2.h remains with the remaining contents, including
redirections.
This also adds the access attribute to __vsnprintf_chk that was missing.
Tested with build-many-glibcs.py.
Reviewed-by: Paul E. Murphy <murphyp@linux.ibm.com>
I used these shell commands:
../glibc/scripts/update-copyrights $PWD/../gnulib/build-aux/update-copyright
(cd ../glibc && git commit -am"[this commit message]")
and then ignored the output, which consisted lines saying "FOO: warning:
copyright statement not found" for each of 7061 files FOO.
I then removed trailing white space from math/tgmath.h,
support/tst-support-open-dev-null-range.c, and
sysdeps/x86_64/multiarch/strlen-vec.S, to work around the following
obscure pre-commit check failure diagnostics from Savannah. I don't
know why I run into these diagnostics whereas others evidently do not.
remote: *** 912-#endif
remote: *** 913:
remote: *** 914-
remote: *** error: lines with trailing whitespace found
...
remote: *** error: sysdeps/unix/sysv/linux/statx_cp.c: trailing lines
In _FORTIFY_SOURCE=3, the size expression may be non-constant,
resulting in branches in the inline functions remaining intact and
causing a tiny overhead. Clang (and in future, gcc) make sure that
the -1 case is always safe, i.e. any comparison of the generated
expression with (size_t)-1 is always false so that bit is taken care
of. The rest is avoidable since we want the _chk variant whenever we
have a size expression and it's not -1.
Rework the conditionals in a uniform way to clearly indicate two
conditions at compile time:
- Either the size is unknown (-1) or we know at compile time that the
operation length is less than the object size. We can call the
original function in this case. It could be that either the length,
object size or both are non-constant, but the compiler, through
range analysis, is able to fold the *comparison* to a constant.
- The size and length are known and the compiler can see at compile
time that operation length > object size. This is valid grounds for
a warning at compile time, followed by emitting the _chk variant.
For everything else, emit the _chk variant.
This simplifies most of the fortified function implementations and at
the same time, ensures that only one call from _chk or the regular
function is emitted.
Signed-off-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
In the context of a function definition, the size hints imply that the
size of an object pointed to by one parameter is another parameter.
This doesn't make sense for the fortified versions of the functions
since that's the bit it's trying to validate.
This is harmless with __builtin_object_size since it has fairly simple
semantics when it comes to objects passed as function parameters.
With __builtin_dynamic_object_size we could (as my patchset for gcc[1]
already does) use the access attribute to determine the object size in
the general case but it misleads the fortified functions.
Basically the problem occurs when access attributes are present on
regular functions that have inline fortified definitions to generate
_chk variants; the attributes get inherited by these definitions,
causing problems when analyzing them. For example with poll(fds, nfds,
timeout), nfds is hinted using the __attr_access as being the size of
fds.
Now, when analyzing the inline function definition in bits/poll2.h, the
compiler sees that nfds is the size of fds and tries to use that
information in the function body. In _FORTIFY_SOURCE=3 case, where the
object size could be a non-constant expression, this information results
in the conclusion that nfds is the size of fds, which defeats the
purpose of the implementation because we're trying to check here if nfds
does indeed represent the size of fds. Hence for this case, it is best
to not have the access attribute.
With the attributes gone, the expression evaluation should get delayed
until the function is actually inlined into its destinations.
Disable the access attribute for fortified function inline functions
when building at _FORTIFY_SOURCE=3 to make this work better. The
access attributes remain for the _chk variants since they can be used
by the compiler to warn when the caller is passing invalid arguments.
[1] https://gcc.gnu.org/pipermail/gcc-patches/2021-October/581125.html
Signed-off-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
I used these shell commands:
../glibc/scripts/update-copyrights $PWD/../gnulib/build-aux/update-copyright
(cd ../glibc && git commit -am"[this commit message]")
and then ignored the output, which consisted lines saying "FOO: warning:
copyright statement not found" for each of 6694 files FOO.
I then removed trailing white space from benchtests/bench-pthread-locks.c
and iconvdata/tst-iconv-big5-hkscs-to-2ucs4.c, to work around this
diagnostic from Savannah:
remote: *** pre-commit check failed ...
remote: *** error: lines with trailing whitespace found
remote: error: hook declined to update refs/heads/master
Adds the access attribute newly introduced in GCC 10 to the subset of
function declarations that are already covered by _FORTIFY_SOURCE and
that don't have corresponding GCC built-in equivalents.
Reviewed-by: DJ Delorie <dj@redhat.com>
We shipped 2.27 with libio.h and _G_config.h still installed but
issuing warnings when used. Let's stop installing them early in 2.28
so that we have plenty of time to think of another plan if there are
problems.
The public stdio.h had a genuine dependency on libio.h for the
complete definitions of FILE and cookie_io_functions_t, and a genuine
dependency on _G_config.h for the complete definitions of fpos_t and
fpos64_t; these are moved to single-type headers.
bits/types/struct_FILE.h also provides a handful of accessor and
bitflags macros so that code is not duplicated between bits/stdio.h
and libio.h. All the other _IO_ and _G_ names used by the public
stdio.h can be replaced with either public names or __-names.
In order to minimize the risk of breaking our own compatibility code,
bits/types/struct_FILE.h preserves the _IO_USE_OLD_IO_FILE mechanism
exactly as it was in libio.h, but you have to define _LIBC to use it,
or it'll error out. Similarly, _IO_lock_t_defined is preserved
exactly, but will error out if used without defining _LIBC.
Internally, include/stdio.h continues to include libio.h, and libio.h
scrupulously provides every _IO_* and _G_* name that it always did,
perhaps now defined in terms of the public names. This is how this
patch avoids touching dozens of files throughout glibc and becoming
entangled with the _IO_MTSAFE_IO mess. The remaining patches in this
series eliminate most of the _G_ names.
Tested on x86_64-linux; in addition to the test suite, I installed the
library in a sysroot and verified that a simple program that uses
stdio.h could be compiled against the installed library, and I also
verified that installed stripped libraries are unchanged.
* libio/bits/types/__fpos_t.h, libio/bits/types/__fpos64_t.h:
New single-type headers split from _G_config.h.
* libio/bits/types/cookie_io_functions_t.h
* libio/bits/types/struct_FILE.h
New single-type headers split from libio.h.
* libio/Makefile: Install the above new headers. Don't install
libio.h, _G_config.h, bits/libio.h, bits/_G_config.h, or
bits/libio-ldbl.h.
* libio/_G_config.h, libio/libio.h: Delete file.
* libio/bits/libio.h: Remove improper-inclusion guard.
Include stdio.h and don't repeat anything that it does.
Define _IO_fpos_t as __fpos_t, _IO_fpos64_t as __fpos64_t,
_IO_BUFSIZ as BUFSIZ, _IO_va_list as __gnuc_va_list,
__io_read_fn as cookie_read_function_t,
__io_write_fn as cookie_write_function_t,
__io_seek_fn as cookie_seek_function_t,
__io_close_fn as cookie_close_function_t,
and _IO_cookie_io_functions_t as cookie_io_functions_t.
Define _STDIO_USES_IOSTREAM, __HAVE_COLUMN, and _IO_file_flags
here, in the "compatibility defines" section. Remove an #if 0
block. Use the "body" macros from bits/types/struct_FILE.h to
define _IO_getc_unlocked, _IO_putc_unlocked, _IO_feof_unlocked,
and _IO_ferror_unlocked.
Move prototypes of __uflow and __overflow...
* libio/stdio.h: ...here. Don't include bits/libio.h.
Don't define _STDIO_USES_IOSTREAM. Get __gnuc_va_list
directly from stdarg.h. Include bits/types/__fpos_t.h,
bits/types/__fpos64_t.h, bits/types/struct_FILE.h,
and, when __USE_GNU, bits/types/cookie_io_functions_t.h.
Use __gnuc_va_list, not _G_va_list; __fpos_t, not _G_fpos_t;
__fpos64_t, not _G_fpos64_t; FILE, not struct _IO_FILE;
cookie_io_functions_t, not _IO_cookie_io_functions_t;
__ssize_t, not _IO_ssize_t. Unconditionally define
BUFSIZ as 8192 and EOF as (-1).
* libio/bits/stdio.h: Add multiple-include guard. Use the "body"
macros from bits/types/struct_FILE.h instead of _IO_* macros
from libio.h; use __gnuc_va_list instead of va_list and __ssize_t
instead of _IO_ssize_t.
* libio/bits/stdio2.h: Similarly.
* libio/iolibio.h: Add multiple-include guard.
Include bits/libio.h after stdio.h.
* libio/libioP.h: Add multiple-include guard.
Include stdio.h and bits/libio.h before iolibio.h.
* include/bits/types/__fpos_t.h, include/bits/types/__fpos64_t.h
* include/bits/types/cookie_io_functions_t.h
* include/bits/types/struct_FILE.h: New wrappers.
* bits/_G_config.h, sysdeps/unix/sysv/linux/_G_config.h:
Get definitions of _G_fpos_t and _G_fpos64_t from
bits/types/__fpos_t.h and bits/types/__fpos64_t.h
respectively. Remove improper-inclusion guards.
* conform/data/stdio.h-data: Update expectations of va_list.
* scripts/check-installed-headers.sh: Remove special case for
libio.h and _G_config.h.
gets has the dubious honor of being the only C89 library feature that
has been completely removed from the current C and C++ standards.
glibc follows suit by not declaring it in _GNU_SOURCE mode either,
but it remains present in older compatibility modes. Internally,
two test cases need to see stdio.h make the declaration, but all our
internal code is of course compiled under _GNU_SOURCE. This is currently
kludged by duplicating the gets declaration, fortify wrapper and all,
in include/stdio.h. Also, the conditional in the public headers for
deciding when to declare gets is complicated and repeated in two places.
This patch adds a new macro to features.h that encapsulates the
complicated rule for when to declare gets. stdio.h and bits/stdio2.h
then simply test __GLIBC_USE (DEPRECATED_GETS), and instead of having
a duplicate gets declaration in include/stdio.h, debug/tst-chk1.c and
stdio-common/tst-gets.c can force gets to be declared.
* include/features.h (__GLIBC_USE_DEPRECATED_GETS): New macro.
* libio/stdio.h, libio/bits/stdio2.h: Condition gets on
__GLIBC_USE (DEPRECATED_GETS). Update comments to indicate
gets was removed from C++ in C++14.
* include/stdio.h: Remove redundant declaration of gets.
* debug/tst-chk1.c, stdio-common/tst-gets.c: Force gets to
be declared, since we are testing it.
* stdio-common/Makefile (tst-gets.c): Compile with
-Wno-deprecated-declarations.
* debug/Makefile (tst-chk1.c, tst-chk2.c, tst-chk3.c, tst-chk4.cc)
(tst-chk5.cc, tst-chk6.cc, tst-lfschk1.c, tst-lfschk2.c)
(tst-lfschk3.c, tst-lfschk4.cc, tst-lfschk5.cc, tst-lfschk6.cc):
Compile with -Wno-deprecated-declarations.
with __warning__/__error__ attributes.
(__warnattr): Define.
* stdlib/bits/stdlib.h (__realpath_chk_warn, __ptsname_r_chk_warn,
__mbstowcs_chk_warn, __wcstombs_chk_warn): New aliases with
__warnattr.
(realpath, ptsname_r, mbstowcs, wcstombs): Call __*_chk_warn instead
of __*_chk if compile time detectable overflow is found.
* libio/bits/stdio2.h (__fgets_chk_warn, __fread_chk_warn,
__fgets_unlocked_chk_warn, __fread_unlocked_chk_warn): New aliases
with __warnattr.
(fgets, fread, fgets_unlocked, fread_unlocked): Call __*_chk_warn
instead of __*_chk if compile time detectable overflow is found.
(__gets_alias): Rename to...
(__gets_warn): ... this. Add __warnattr.
(gets): Call __gets_warn instead of __gets_alias.
* socket/bits/socket2.h (__recv_chk_warn, __recvfrom_chk_warn): New
aliases with __warnattr.
(recv, recvfrom): Call __*_chk_warn instead of __*_chk if compile
time detectable overflow is found.
* posix/bits/unistd.h (__read_chk_warn, __pread_chk_warn,
__pread64_chk_warn, __readlink_chk_warn, __readlinkat_chk_warn,
__getcwd_chk_warn, __confstr_chk_warn, __getgroups_chk_warn,
__ttyname_r_chk_warn, __getlogin_r_chk_warn, __gethostname_chk_warn,
__getdomainname_chk_warn): New aliases with __warnattr.
(read, pread, pread64, readlink, readlinkat, getcwd, confstr,
getgroups, ttyname_r, getlogin_r, gethostname, getdomainname): Call
__*_chk_warn instead of __*_chk if compile time detectable overflow
is found.
(__getgroups_chk): Rename argument to __listlen from listlen.
(__getwd_alias): Rename to...
(__getwd_warn): ... this. Add __warnattr.
(getwd): Call __getwd_warn instead of __getwd_alias.
* wcsmbs/bits/wchar2.h (__wmemcpy_chk_warn, __wmemmove_chk_warn,
__wmempcpy_chk_warn, __wmemset_chk_warn, __wcsncpy_chk_warn,
__wcpncpy_chk_warn, __fgetws_chk_warn, __fgetws_unlocked_chk_warn,
__mbsrtowcs_chk_warn, __wcsrtombs_chk_warn, __mbsnrtowcs_chk_warn,
__wcsnrtombs_chk_warn): New aliases with __warnattr.
(wmemcpy, wmemmove, wmempcpy, wmemset, mbsrtowcs, wcsrtombs,
mbsnrtowcs, wcsnrtombs): Call __*_chk_warn instead of __*_chk if
compile time detectable overflow is found.
(wcsncpy, wcpncpy): Likewise. For constant __n fix check whether
to use __*_chk or not.
(fgetws, fgetws_unlocked): Divide __bos by sizeof (wchar_t), both
in comparisons which function should be called and in __*_chk*
arguments. Call __*_chk_warn instead of __*_chk if compile time
detectable overflow is found.
(swprintf, vswprintf): Divide __bos by sizeof (wchar_t) in
__*_chk argument.
* debug/tst-chk1.c (do_test): Add a few more tests.
* misc/bits/syslog.h (syslog): When __va_arg_pack is defined,
implement as __extern_always_inline function.
(vsyslog): Define as __extern_always_inline function unconditionally.
* libio/bits/stdio2.h (sprintf, snprintf, printf, fprintf):
When __va_arg_pack is defined, implement as __extern_always_inline
functions.
(vsprintf, vsnprintf, vprintf, vfprintf): Define as
__extern_always_inline functions unconditionally.
* libio/bits/stdio.h (vprintf): Ifdef out the inline when
bits/stdio2.h will be included.
* wcsmbs/bits/wchar2.h (__swprintf_alias): New redirect.
(swprintf, wprintf, fwprintf): When __va_arg_pack is defined,
implement as __extern_always_inline functions.
(vswprintf, vwprintf, vfwprintf): Define as
__extern_always_inline functions unconditionally.
* debug/tst-chk1.c (do_test): Enable remaining tests for C++.
2007-09-03 Jakub Jelinek <jakub@redhat.com>
* misc/sys/cdefs.h (__extern_inline, __extern_always_inline): Only
define in C++ for GCC 4.3+, in C++ always use __gnu_inline__
attribute.
* include/features.h (__USE_EXTERN_INLINES): Define only when
__extern_inline is defined.
* stdlib/stdlib.h: Include bits/stdlib.h when __extern_always_inline
is defined instead of when not __cplusplus.
* misc/sys/syslog.h: Include bits/syslog.h when __extern_always_inline
is defined instead of when not __cplusplus.
* socket/sys/socket.h: Include bits/socket2.h when
__extern_always_inline is defined instead of when not __cplusplus.
* libio/stdio.h: Include bits/stdio2.h when __extern_always_inline
is defined instead of when not __cplusplus.
* posix/unistd.h: Include bits/unistd.h when __extern_always_inline
is defined instead of when not __cplusplus.
* string/string.h: Include bits/string3.h when __extern_always_inline
is defined instead of when not __cplusplus.
* wcsmbs/wchar.h: Include bits/wchar2.h when __extern_always_inline
is defined instead of when not __cplusplus.
(btowc, wctob): Don't guard the inlines with ifndef __cplusplus.
* io/fcntl.h: Don't include bits/fcntl2.h if __extern_always_inline
is not defined.
* misc/bits/syslog-ldbl.h: Guard *_chk stuff with
defined __extern_always_inline instead of !defined __cplusplus.
* libio/bits/stdio-ldbl.h: Likewise.
* wcsmbs/bits/wchar-ldbl.h: Likewise.
* misc/bits/syslog.h (syslog): Don't define for C++.
(vsyslog): Use __extern_always_inline function for C++ instead of
a macro.
* libio/bits/stdio.h (__STDIO_INLINE): Define to __extern_inline
whenever that macro is defined.
(vprintf): Don't provide the inline for C++.
(fread_unlocked, fwrite_unlocked): Don't define the macros for C++.
* libio/bits/stdio2.h (sprintf, snprintf, printf, fprintf): Don't
define the macros for C++.
(vsprintf, vsnprintf, vprintf, vfprintf): Define as
__extern_always_inline functions for C++.
* io/sys/stat.h (stat, lstat, fstat, fstatat, mknod, mknodat,
stat64, lstat64, fstat64, fstatat64): Don't define if not
__USE_EXTERN_INLINES.
* wcsmbs/bits/wchar2.h: Fix #error message.
(swprintf, wprintf, fwprintf): Don't define the macros for C++.
(vswprintf, vwprintf, vfwprintf): Define using
__extern_always_inline functions for C++.
* string/bits/string3.h: Don't #undef macros if __cplusplus.
(memcpy, memmove, mempcpy, memset, bcopy, bzero, strcpy, stpcpy,
strncpy, strcat, strncat): Define as __extern_always_inline
functions instead of macros for C++.
* math/bits/cmathcalls.h: Guard __extern_inline routines with
defined __extern_inline.
* sysdeps/alpha/fpu/bits/mathinline.h (__MATH_INLINE): Define
to __extern_inline whenever that macro is defined.
* sysdeps/ia64/fpu/bits/mathinline.h (__MATH_INLINE): Likewise.
* sysdeps/i386/fpu/bits/mathinline.h (__MATH_INLINE): Likewise.
* sysdeps/i386/i486/bits/string.h (__STRING_INLINE): Likewise.
* sysdeps/s390/bits/string.h (__STRING_INLINE): Likewise.
* sysdeps/s390/fpu/bits/mathinline.h (__MATH_INLINE): Likewise.
* sysdeps/powerpc/fpu/bits/mathinline.h (__MATH_INLINE): Likewise.
* sysdeps/x86_64/fpu/bits/mathinline.h (__MATH_INLINE): Likewise.
* sysdeps/sparc/fpu/bits/mathinline.h (__MATH_INLINE): Likewise.
* sysdeps/unix/sysv/linux/sys/sysmacros.h (gnu_dev_major,
gnu_dev_minor, gnu_dev_makedev): Remove __extern_inline from
prototypes. Only provide __extern_inline routines if
__USE_EXTERN_INLINES.
* debug/Makefile: Add rules to build and run tst-{,lfs}chk{4,5,6}
tests.
* debug/tst-chk1.c (do_prepare, do_test): Allow compilation as C++.
For now avoid some *printf tests in C++. Skip all testing
if __USE_FORTIFY_LEVEL is defined, but __extern_always_inline macro
is not.
* debug/tst-chk4.cc: New file.
* debug/tst-chk5.cc: New file.
* debug/tst-chk6.cc: New file.
* debug/tst-lfschk4.cc: New file.
* debug/tst-lfschk5.cc: New file.
* debug/tst-lfschk6.cc: New file.
* include/wchar.h (__vfwprintf_chk, __vswprintf_chk): Avoid
prototypes in C++.
* include/stdio.h (__sprintf_chk, __snprintf_chk, __vsprintf_chk,
__vsnprintf_chk, __printf_chk, __fprintf_chk, __vprintf_chk,
__vfprintf_chk, __fgets_unlocked_chk, __fgets_chk): Likewise.
map if requested.
* debug/chk_fail.c: Request backtrace and memory map dump.
* Versions.def: Add GLIBC_2.4 for libc.
* debug/fgets_chk.c: New file.
* debug/fgets_u_chk.c: New file.
* debug/getcwd_chk.c: New file.
* debug/getwd_chk.c: New file.
* debug/readlink_chk.c: New file.
* debug/read_chk.c: New file.
* debug/pread_chk.c: New file.
* debug/pread64_chk.c: New file.
* debug/recv_chk.c: New file.
* debug/recvfrom_chk.c: New file.
* debug/Versions: Add all new functions with version GLIBC_2.4.
* debug/Makefile (routines): Add fgets_chk, fgets_u_chk, read_chk,
pread_chk, pread64_chk, recv_chk, recvfrom_chk, readlink_chk,
getwd_chk, and getcwd_chk. Plus appropriate CFLAGS definitions.
* debug/tst-chk1.c: Add more tests.
* libio/bits/stdio2.h: Add macros for fgets and fgets_unlocked.
* include/stdio.h: Declare __fgets_chk and __fgets_unlocked_chk.
* posix/unistd.h: Include <bits/unistd.h> for fortification.
* posix/bits/unistd.h: New file.
* posix/Makefile (headers): Add bits/unistd.h.
* socket/sys/socket.h: Include <bits/socket2.h> for fortification.
* socket/bits/socket2.h: New file.
* socket/Makefile (headers): Add bits/socket2.h.
* string/bits/string3.h: Extend memset macro to check for zero 3rd
parameter and use __memset_zero_constant_len_parameter in that case.
* sysdeps/generic/memset_chk.c: Add
__memset_zero_constant_len_parameter alias and linker warning.
* debug/Versions: Add __memset_zero_constant_len_parameter to libc
with version GLIBC_2.4.
* sysdeps/generic/bits/types.h: Don't unnecessarily use __extension__
in __STD_TYPE definition.
2005-02-21 Jakub Jelinek <jakub@redhat.com>
* malloc/malloc.c (malloc_printerr): If MALLOC_CHECK_={5,7}, print
the error message rather than program name.
2005-02-21 Ulrich Drepper <drepper@redhat.com>
