Old implementation of realpath allocates a PATH_MAX using alloca for
each symlink in the path, leading to MAXSYMLINKS times PATH_MAX
maximum stack usage.
The test create a symlink with __eloop_threshold() loops and creates
a thread with minimum stack size (obtained through
support_small_stack_thread_attribute). The thread issues a stack
allocations that fill the thread allocated stack minus some slack
plus and the realpath usage (which assumes a bounded stack usage).
If realpath uses more than about 2 * PATH_MAX plus some slack it
triggers a stackoverflow.
Checked on x86_64-linux-gnu and i686-linux-gnu.
Reviewed-by: DJ Delorie <dj@redhat.com>
POSIX states that system returned code for failure to execute the shell
shall be as if the shell had terminated using _exit(127). This
behaviour was removed with 5fb7fc9635.
Checked on x86_64-linux-gnu.
It sync with gnulib version ae9fb3d66. The testcase for BZ#23741
(stdlib/test-bz22786.c) is adjusted to check also for ENOMEM.
The patch fixes multiple realpath issues:
- Portability fixes for errno clobbering on free (BZ#10635). The
function does not call free directly anymore, although it might be
done through scratch_buffer_free. The free errno clobbering is
being tracked by BZ#17924.
- Pointer arithmetic overflows in realpath (BZ#26592).
- Realpath cyclically call __alloca(path_max) to consume too much
stack space (BZ#26341).
- Realpath mishandles EOVERFLOW; stat not needed anyway (BZ#24970).
The check is done through faccessat now.
Checked on x86_64-linux-gnu and i686-linux-gnu.
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
The len variable is only used in the else branch.
We don't need the call to strlen if the name is 0 or 1 characters long.
2019-10-02 Lode Willems <Lode.Willems@UGent.be>
* tdlib/getenv.c: Move the call to strlen into the branch it's used.
inttypes.h has inline implementations of the strtoimax, strtoumax,
wcstoimax and wcstoumax functions, despite the corresponding stdlib.h
and wchar.h inlines having been removed in 2007 (commit
9b2e9577b2).
Remove those inlines, thereby eliminating all references to the
corresponding __*_internal functions from installed headers (so they
could be made into compat symbols in future if desired).
Tested for x86_64 and x86.
The functions strtoimax, strtoumax, wcstoimax, wcstoumax currently
have three implementations each (wordsize-32, wordsize-64 and dummy
implementation in stdlib/ using #error), defining the functions as
thin wrappers round corresponding *_internal functions. Simplify the
code by changing them into aliases of functions such as strtol and
wcstoull. This is more consistent with how e.g. imaxdiv is handled.
Tested for x86_64 and x86.
It replaces the internal usage of __{f,l}xstat{at}{64} with the
__{f,l}stat{at}{64}. It should not change the generate code since
sys/stat.h explicit defines redirections to internal calls back to
xstat* symbols.
Checked with a build for all affected ABIs. I also check on
x86_64-linux-gnu and i686-linux-gnu.
Reviewed-by: Lukasz Majewski <lukma@denx.de>
Bug 26137 reports spurious "inexact" exceptions from strtod, on 32-bit
systems only, for a decimal argument that is exactly 1 + 2^-32. In
fact the same issue also appears for 1 + 2^-64 and 1 + 2^-96 as
arguments to strtof128 on 32-bit systems, and 1 + 2^-64 as an argument
to strtof128 on 64-bit systems. In FE_DOWNWARD or FE_TOWARDZERO mode,
the return value is also incorrect.
The problem is in the multiple-precision division logic used in the
case of dividing by a denominator that occupies at least three GMP
limbs. There was a comment "The division does not work if the upper
limb of the two-limb mumerator is greater than the denominator.", but
in fact there were problems for the case of equality (that is, where
the high limbs are equal, offset by some multiple of the GMP limb
size) as well. In such cases, the code used "quot = ~(mp_limb_t) 0;"
(with subsequent correction if that is an overestimate), because
udiv_qrnnd does not support the case of equality, but it's possible
for the shifted numerator to be greater than or equal to the
denominator, in which case that is an underestimate. To avoid that,
this patch changes the ">" condition to ">=", meaning the first
division is done with a zero high word.
The tests added are all 1 + 2^-n for n from 1 to 113 except for those
that were already present in tst-strtod-round-data.
Tested for x86_64 and x86.
On other platforms, RAND_MAX (which is the range of rand(3))
may differ from 2^31-1 (which is the range of random(3)).
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
The function mbstowcs, by an XSI extension to POSIX, accepts a null
pointer for the destination wchar_t array. This API behaviour allows
you to use the function to compute the length of the required wchar_t
array i.e. does the conversion without storing it and returns the
number of wide characters required.
We remove the __write_only__ markup for the first argument because it
is not true since the destination may be a null pointer, and so the
length argument may not apply. We remove the markup otherwise the new
test case cannot be compiled with -Werror=nonnull.
We add a new test case for mbstowcs which exercises the destination is
a null pointer behaviour which we have now explicitly documented.
The mbsrtowcs and mbsnrtowcs behave similarly, and mbsrtowcs is
documented as doing this in C11, even if the standard doesn't come out
and call out this specific use case. We add one note to each of
mbsrtowcs and mbsnrtowcs to call out that they support a null pointer
for the destination.
The wcsrtombs function behaves similarly but in the other way around
and allows you to use a null destination pointer to compute how many
bytes you would need to convert the wide character input. We document
this particular case also, but leave wcsnrtombs as a references to
wcsrtombs, so the reader must still read the details of the semantics
for wcsrtombs.
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>
Improve the commentary to aid future developers who will stumble
upon this novel, yet not always perfect, mechanism to support
alternative formats for long double.
Likewise, rename __LONG_DOUBLE_USES_FLOAT128 to
__LDOUBLE_REDIRECTS_TO_FLOAT128_ABI now that development work
has settled down. The command used was
git grep -l __LONG_DOUBLE_USES_FLOAT128 ':!./ChangeLog*' | \
xargs sed -i 's/__LONG_DOUBLE_USES_FLOAT128/__LDOUBLE_REDIRECTS_TO_FLOAT128_ABI/g'
Reviewed-by: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com>
This patch removes the IEEE_DOUBLE_BIG_ENDIAN and
IEEE_DOUBLE_MIXED_ENDIAN macros from gmp-impl.h and gmp-mparam.h, and
the ieee_double_extract union from gmp-impl.h. The macros were used
only in defining the union, which was used nowhere in glibc. As GMP's
gmp-impl.h is over 5000 lines, the file in glibc is so far from the
GMP version that it doesn't seem to make sense to keep things there
that are not relevant in glibc. (I expect there is plenty more in the
header after this patch that is also not relevant in glibc and can be
cleaned up later.)
Tested with build-many-glibcs.py that installed stripped shared
libraries are unchanged by this patch.
This patch adds the GRND_INSECURE constant from Linux 5.6 to glibc's
sys/random.h. This is also added to the documentation. The constant
acts as a no-op for the Hurd implementation (as that doesn't check
whether the flags are known), which is semantically fine, while older
Linux kernels reject unknown flags with an EINVAL error.
Tested for x86_64.
All functions that have a format string, which can consume a long double
argument, must have one version for each long double format supported on
a platform. On powerpc64le, these functions currently have two versions
(i.e.: long double with the same format as double, and long double with
IBM Extended Precision format). Support for a third long double format
option (i.e. long double with IEEE long double format) is being prepared
and all the aforementioned functions now have a third version (not yet
exported on the master branch, but the code is in).
For these functions to get selected (during build time), references to
them in user programs (or dependent libraries) must get redirected to
the aforementioned new versions of the functions. This patch installs
the header magic required to perform such redirections.
Notice, however, that since the redirections only happen when
__LONG_DOUBLE_USES_FLOAT128 is set to 1, and no platform (including
powerpc64le) currently does it, no redirections actually happen.
Redirections and the exporting of the new functions will happen at the
same time (when powerpc64le adds ldbl-128ibm-compat to their Implies.
Reviewed-by: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com>
Reviewed-by: Paul E. Murphy <murphyp@linux.vnet.ibm.com>
The namespace pollution results in conform test failures if the tests
are run __USE_EXTERN_INLINES defined (e.g., when configuring with
CC="gcc -O3" CXX="g++ -O3").
Since commit a3cc4f48e9 ("Remove
--as-needed configure test."), --as-needed support is no longer
optional.
The macros are not much shorter and do not provide documentary
value, either, so this commit removes them.
Similarly to what has been done for printf-like functions, more
specifically to the internal implementation in __vfprintf_internal, this
patch extends __vstrfmon_l_internal to deal with long double values with
binary128 format (as a third format option and reusing the float128
implementation).
Tested for powerpc64le, powerpc64, x86_64, and with build-many-glibcs.
Reviewed-by: Paul E. Murphy <murphyp@linux.ibm.com>
As discussed previously on libc-alpha [1], this patch follows up the idea
and add both the __attribute_alloc_size__ on malloc functions (malloc,
calloc, realloc, reallocarray, valloc, pvalloc, and memalign) and limit
maximum requested allocation size to up PTRDIFF_MAX (taking into
consideration internal padding and alignment).
This aligns glibc with gcc expected size defined by default warning
-Walloc-size-larger-than value which warns for allocation larger than
PTRDIFF_MAX. It also aligns with gcc expectation regarding libc and
expected size, such as described in PR#67999 [2] and previously discussed
ISO C11 issues [3] on libc-alpha.
From the RFC thread [4] and previous discussion, it seems that consensus
is only to limit such requested size for malloc functions, not the system
allocation one (mmap, sbrk, etc.).
The implementation changes checked_request2size to check for both overflow
and maximum object size up to PTRDIFF_MAX. No additional checks are done
on sysmalloc, so it can still issue mmap with values larger than
PTRDIFF_T depending on the requested size.
The __attribute_alloc_size__ is for functions that return a pointer only,
which means it cannot be applied to posix_memalign (see remarks in GCC
PR#87683 [5]). The runtimes checks to limit maximum requested allocation
size does applies to posix_memalign.
Checked on x86_64-linux-gnu and i686-linux-gnu.
[1] https://sourceware.org/ml/libc-alpha/2018-11/msg00223.html
[2] https://gcc.gnu.org/bugzilla//show_bug.cgi?id=67999
[3] https://sourceware.org/ml/libc-alpha/2011-12/msg00066.html
[4] https://sourceware.org/ml/libc-alpha/2018-11/msg00224.html
[5] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87683
[BZ #23741]
* malloc/hooks.c (malloc_check, realloc_check): Use
__builtin_add_overflow on overflow check and adapt to
checked_request2size change.
* malloc/malloc.c (__libc_malloc, __libc_realloc, _mid_memalign,
__libc_pvalloc, __libc_calloc, _int_memalign): Limit maximum
allocation size to PTRDIFF_MAX.
(REQUEST_OUT_OF_RANGE): Remove macro.
(checked_request2size): Change to inline function and limit maximum
requested size to PTRDIFF_MAX.
(__libc_malloc, __libc_realloc, _int_malloc, _int_memalign): Limit
maximum allocation size to PTRDIFF_MAX.
(_mid_memalign): Use _int_memalign call for overflow check.
(__libc_pvalloc): Use __builtin_add_overflow on overflow check.
(__libc_calloc): Use __builtin_mul_overflow for overflow check and
limit maximum requested size to PTRDIFF_MAX.
* malloc/malloc.h (malloc, calloc, realloc, reallocarray, memalign,
valloc, pvalloc): Add __attribute_alloc_size__.
* stdlib/stdlib.h (malloc, realloc, reallocarray, valloc): Likewise.
* malloc/tst-malloc-too-large.c (do_test): Add check for allocation
larger than PTRDIFF_MAX.
* malloc/tst-memalign.c (do_test): Disable -Walloc-size-larger-than=
around tests of malloc with negative sizes.
* malloc/tst-posix_memalign.c (do_test): Likewise.
* malloc/tst-pvalloc.c (do_test): Likewise.
* malloc/tst-valloc.c (do_test): Likewise.
* malloc/tst-reallocarray.c (do_test): Replace call to reallocarray
with resulting size allocation larger than PTRDIFF_MAX with
reallocarray_nowarn.
(reallocarray_nowarn): New function.
* NEWS: Mention the malloc function semantic change.
This test would fail unnecessarily if the user running it had more than
64 groups since getgroups returns EINVAL if the size provided is less
than the number of supplementary group IDs. Instead dynamically
determine the number of supplementary groups the user has.
inttypes.h and stdint.h are in sysdeps/generic, but there are no other
versions of these headers anywhere in the source tree, so they aren’t
actually system-dependent. Move them to the subdirectory that
installs them (stdlib).
Reviewed-by: Joseph Myers <joseph@codesourcery.com>
* sysdeps/generic/inttypes.h, sysdeps/generic/stdint.h:
Move to stdlib.
* include/inttypes.h: Adjust to match.
* include/stdint.h: New wrapper.
When running the testsuite, building stdlib/isomac.c outputs the
following warning:
gcc -O -D_GNU_SOURCE -DIS_IN_build -include /home/aurel32/glibc-build/config.h isomac.c -o /home/aurel32/glibc-build/stdlib/isomac
isomac.c: In function ‘get_null_defines’:
isomac.c:260:3: warning: implicit declaration of function ‘close’; did you mean ‘pclose’? [-Wimplicit-function-declaration]
close (fd);
^~~~~
pclose
Fix that by adding the <unistd.h> include.
Changelog:
* stdlib/isomac.c: Include <unistd.h>.
This patch updates longlong.h from GCC. There were no local changes
in glibc (the previous version was identical to the r232143 GCC
version, apart from copyright dates which had been updated in both
places), so this patch makes it identical to the version in GCC again.
Tested for x86_64 and x86. Also tested with build-many-glibcs.py for
its RISC-V configurations, as the glibc architecture with the most
substantial changes in longlong.h in this patch.
* stdlib/longlong.h: Update from GCC.
There are a lot more printf variants than there are scanf variants,
and the code for setting up and tearing down their custom FILE
variants around the call to __vf(w)printf is more complicated and
variable. Therefore, I have added _internal versions of all the
v*printf variants, rather than introducing helper routines so that
they can all directly call __vf(w)printf_internal, as was done with
scanf.
As with the scanf changes, in this patch the _internal functions still
look at the environmental mode bits and all callers pass 0 for the
flags parameter.
Several of the affected public functions had _IO_ name aliases that
were not exported (but, in one case, appeared in libio.h anyway);
I was originally planning to leave them as aliases to avoid having
to touch internal callers, but it turns out ldbl_*_alias only work
for exported symbols, so they've all been removed instead. It also
turns out there were hardly any internal callers. _IO_vsprintf and
_IO_vfprintf *are* exported, so those two stick around.
Summary for the changes to each of the affected symbols:
_IO_vfprintf, _IO_vsprintf:
All internal calls removed, thus the internal declarations, as well
as uses of libc_hidden_proto and libc_hidden_def, were also removed.
The external symbol is now exposed via uses of ldbl_strong_alias
to __vfprintf_internal and __vsprintf_internal, respectively.
_IO_vasprintf, _IO_vdprintf, _IO_vsnprintf,
_IO_vfwprintf, _IO_vswprintf,
_IO_obstack_vprintf, _IO_obstack_printf:
All internal calls removed, thus declaration in internal headers
were also removed. They were never exported, so there are no
aliases tying them to the internal functions. I.e.: entirely gone.
__vsnprintf:
Internal calls were always preceded by macros such as
#define __vsnprintf _IO_vsnprintf, and
#define __vsnprintf vsnprintf
The macros were removed and their uses replaced with calls to the
new internal function __vsnprintf_internal. Since there were no
internal calls, the internal declaration was also removed. The
external symbol is preserved with ldbl_weak_alias to ___vsnprintf.
__vfwprintf:
All internal calls converted into calls to __vfwprintf_internal,
thus the internal declaration was removed. The function is now a
wrapper that calls __vfwprintf_internal. The external symbol is
preserved.
__vswprintf:
Similarly, but no external symbol.
__vasprintf, __vdprintf, __vfprintf, __vsprintf:
New internal wrappers. Not exported.
vasprintf, vdprintf, vfprintf, vsprintf, vsnprintf,
vfwprintf, vswprintf,
obstack_vprintf, obstack_printf:
These functions used to be aliases to the respective _IO_* function,
they are now aliases to their respective __* functions.
Tested for powerpc and powerpc64le.
On platforms where long double used to have the same format as double,
but later switched to a different format (alpha, s390, sparc, and
powerpc), accessing the older behavior is possible and it happens via
__nldbl_* functions (not on the API, but accessible from header
redirection and from compat symbols). These functions write to the
global flag __ldbl_is_dbl, which tells other functions that long double
variables should be handled as double. This patch takes the first step
towards removing this global flag and creates __vstrfmon_l_internal,
which takes an explicit flags parameter.
This change arguably makes the generated code slightly worse on
architectures where __ldbl_is_dbl is never true; right now, on those
architectures, it's a compile-time constant; after this change, the
compiler could theoretically prove that __vstrfmon_l_internal was
never called with a nonzero flags argument, but it would probably need
LTO to do it. This is not performance critical code and I tend to
think that the maintainability benefits of removing action at a
distance are worth it. However, we _could_ wrap the runtime flag
check with a macro that was defined to ignore its argument and always
return false on architectures where __ldbl_is_dbl is never true, if
people think the codegen benefits are important.
Tested for powerpc and powerpc64le.
On systems without enough random-access memory, stdlib/test-bz22786
will go deeply into swap and time out, even with a substantial
TIMEOUTFACTOR. This commit adds a facility to construct repeating
strings with alias mappings, so that the requirement for physical
memory, and uses it in stdlib/test-bz22786.
glibc support for 64-bit time_t on 32-bit architectures
will involve:
- Using 64-bit times inside glibc, with conversions
to and from 32-bit times taking place as necessary
for interfaces using such times.
- Adding 64-bit-time support in the glibc public API.
This support should be dynamic, i.e. glibc should
provide both 32-bit and 64-bit implementations and
let user code choose at compile time whether to use
the 32-bit or 64-bit interfaces.
This requires a glibc-internal name for a type for times
that are always 64-bit.
Based on __TIMESIZE, a new macro is defined, __TIME64_T_TYPE,
which is always the right __*_T_TYPE to hold a 64-bit-time.
__TIME64_T_TYPE equals __TIME_T_TYPE if __TIMESIZE equals 64
and equals __SQUAD_T_TYPE otherwise.
__time64_t can then replace uses of internal_time_t.
This patch was tested by running 'make check' on branch
master then applying this patch and its predecessor and
running 'make check' again, and checking that both 'make
check' yield identical results. This was done on
x86_64-linux-gnu and i686-linux-gnu.
* bits/time64.h: New file.
* include/time.h: Replace internal_time_t with __time64_t.
* posix/bits/types (__time64_t): Add.
* stdlib/Makefile: Add bits/time64.h to includes.
* time/tzfile.c: Replace internal_time_t with __time64_t.
To determine whether the default time_t interfaces are 32-bit
and so need conversions, or are 64-bit and so are compatible
with the internal 64-bit type without conversions, a macro
giving the size of the default time_t is also required.
This macro is called __TIMESIZE.
This macro can then be used instead of __WORDSIZE in msq-pad.h
and shm-pad.h files, which in turn allows removing their x86
variants, and in sem-pad.h files but keeping the x86 variant.
This patch was tested by running 'make check' on branch master
then applying this patch and running 'make check' again, and
checking that both 'make check' yield identical results.
This was done on x86_64-linux-gnu and i686-linux-gnu.
* bits/timesize.h: New file.
* stdlib/Makefile (headers): Add bits/timesize.h.
* sysdeps/unix/sysv/linux/bits/msq-pad.h
(__MSQ_PAD_AFTER_TIME): Use __TIMESIZE instead of __WORDSIZE.
* sysdeps/unix/sysv/linux/bits/sem-pad.h
(__SEM_PAD_AFTER_TIME): Likewise.
* sysdeps/unix/sysv/linux/bits/shm-pad.h
(__SHM_PAD_AFTER_TIME): Likewise.
* sysdeps/unix/sysv/linux/hppa/bits/msq-pad.h
(__MSQ_PAD_BEFORE_TIME): Likewise.
* sysdeps/unix/sysv/linux/hppa/bits/sem-pad.h
(__SEM_PAD_BEFORE_TIME): Likewise.
* sysdeps/unix/sysv/linux/hppa/bits/shm-pad.h
(__SHM_PAD_BEFORE_TIME, __SHM_PAD_BETWEEN_TIME_AND_SEGSZ): Likewise.
* sysdeps/unix/sysv/linux/mips/bits/msq-pad.h
(__MSQ_PAD_AFTER_TIME, __MSQ_PAD_BEFORE_TIME): Likewise.
* sysdeps/unix/sysv/linux/powerpc/bits/msq-pad.h
(__MSQ_PAD_BEFORE_TIME): Likewise.
* sysdeps/unix/sysv/linux/powerpc/bits/sem-pad.h
(__SEM_PAD_BEFORE_TIME): Likewise.
* sysdeps/unix/sysv/linux/powerpc/bits/shm-pad.h
(__SHM_PAD_BEFORE_TIME, __SHM_PAD_BETWEEN_TIME_AND_SEGSZ): Likewise.
* sysdeps/unix/sysv/linux/sparc/bits/msq-pad.h
(__MSQ_PAD_BEFORE_TIME): Likewise.
* sysdeps/unix/sysv/linux/sparc/bits/sem-pad.h
(__SEM_PAD_BEFORE_TIME): Likewise.
* sysdeps/unix/sysv/linux/sparc/bits/shm-pad.h
(__SHM_PAD_BEFORE_TIME): Likewise.
* sysdeps/unix/sysv/linux/x86/bits/msq-pad.h: Delete file.
* sysdeps/unix/sysv/linux/x86/bits/shm-pad.h: Likewise.
* sysdeps/unix/sysv/linux/x86/bits/timesize.h: New file.
The function f1a, executed on a stack of size 32k, allocates an object of
size 32k on the stack. Make the stack variables static to reduce
excessive stack usage.
If the compiler reduces the stack usage in function f1 before calling
into function f2, then when we swapcontext back to f1 and continue
execution we may overwrite registers that were spilled to the stack
while f2 was executing. Later when we return to f2 the corrupt
registers will be reloaded from the stack and the test will crash. This
was most commonly observed on i686 with __x86.get_pc_thunk.dx and
needing to save and restore $edx. Overall i686 has few registers and
the spilling to the stack is bound to happen, therefore the solution to
making this test robust is to split function f1 into two parts f1a and
f1b, and allocate f1b it's own stack such that subsequent execution does
not overwrite the stack in use by function f2.
Tested on i686 and x86_64.
Signed-off-by: Carlos O'Donell <carlos@redhat.com>
