The soft-fp implementations of fma produce -Wuninitialized warnings
because, in the cases where the result is not a nonzero finite value,
the soft-fp does not set the exponent of the result since the (cooked)
packing will do so, but the compiler does not then see that the
exponent is always set in packing before it's used if it wasn't set
earlier. This patch uses DIAG_* macros to suppress those warnings.
Tested for mips64. (In fact this allows the mips64 build to complete
with the -Wno-uninitialized removed from math/Makefile, but more
cleanups are still needed in the ldbl-128ibm code for uninitialized
warnings there.)
* soft-fp/fmadf4.c: Include <libc-internal.h>.
(__fma): Ignore uninitialized warnings around packing.
* soft-fp/fmasf4.c: Include <libc-internal.h>.
(__fmaf): Ignore uninitialized warnings around packing.
* soft-fp/fmatf4.c: Include <libc-internal.h>.
(__fmal): Ignore uninitialized warnings around packing.
The ldbl-128 and ldbl-128ibm implementations of tanl produce
uninitialized variable warnings with -Wuninitialized because of a
variable that is initialized only conditionally, then used under the
same conditions under which it is set. This patch uses DIAG_* macros
to suppress those warnings.
Tested for powerpc and mips64.
* sysdeps/ieee754/ldbl-128/k_tanl.c: Include <libc-internal.h>.
(__kernel_tanl): Ignore uninitialized warnings around use of SIGN.
* sysdeps/ieee754/ldbl-128ibm/k_tanl.c: Include <libc-internal.h>.
(__kernel_tanl): Ignore uninitialized warnings around use of SIGN.
The ldbl-128 and ldbl-128ibm implementations of erfcl produce
uninitialized variable warnings with -Wuninitialized because of switch
statements where in fact one of the cases will always be executed, but
the compiler does not see that these cases cover all possibilities
(and because the reasoning that it does involves inequalities on the
representation of a floating point value leading to a set of possible
values for 8.0 times that value, converted to int, it's highly
nontrivial for the compiler to see that). This patch fixes those
warnings by converting the last case in those switch statements to a
"default" case.
Tested for powerpc and mips64.
* sysdeps/ieee754/ldbl-128/s_erfl.c (__erfcl): Make case 9 in
switch statement into default case.
* sysdeps/ieee754/ldbl-128ibm/s_erfl.c (__erfcl): Likewise.
The ldbl-128 and ldbl-128ibm implementations of asinl produce
uninitialized variable warnings with -Wuninitialized because the code
for small arguments in fact always returns but the compiler cannot see
this and instead sees that a variable would be uninitialized if the
"if (huge + x > one)" conditional used to force the "inexact"
exception were false.
All the code in libm trying to force "inexact" for functions that are
not exactly defined is suspect and should be removed at some point
given that we now have a clear definition of the accuracy goals for
libm functions which, following C99/C11, does not require anything
about "inexact" for most functions (likewise, the multi-precision code
that tries to give correctly-rounded results, very slowly, for
functions for which the goals clearly do not include correct rounding,
if the faster paths are accurate enough). However, for now this patch
simply changes the code to use math_force_eval, rather than "if", to
ensure the evaluation of the inexact computation.
Tested for powerpc and mips64.
* sysdeps/ieee754/ldbl-128/e_asinl.c (__ieee754_asinl): Don't use
a conditional in forcing "inexact".
* sysdeps/ieee754/ldbl-128ibm/e_asinl.c (__ieee754_asinl):
Likewise.
My review of conformtest expectations for POSIX showed up that the
_POSIX2_C_VERSION macro, required by POSIX and XPG standards before
2001, was missing in unistd.h, having been removed on 2003-04-03
despite those standards still being supported. This patch adds it
back. As it's in the implementation namespace, there's no need for it
to be conditional, and other such macros aren't conditional in this
header either.
Tested for x86_64 and x86 (testsuite). Note that this *does* change
the installed libraries, because it affects the sysconf support
(present all along) for _SC_2_C_VERSION.
[BZ #438]
* posix/unistd.h (_POSIX2_C_VERSION): New macro.
* conform/Makefile (test-xfail-POSIX/unistd.h/conform): Remove
variable.
pathconf (sysdeps/unix/sysv/linux/pathconf.c) uses basename. But
pathconf is in POSIX back to 1990 while basename is only reserved with
external linkage in those standards including XPG functions. This
patch fixes this namespace issue in the usual way, renaming basename
to __basename and making it into a weak alias.
Tested for x86_64 and x86 (testsuite, and that disassembly of
installed shared libraries is unchanged by the patch).
[BZ #18444]
* string/basename.c (basename): Rename to __basename and define as
weak alias of __basename. Use libc_hidden_weak.
* include/string.h (__basename): Declare. Use libc_hidden_proto.
* sysdeps/unix/sysv/linux/pathconf.c (distinguish_extX): Call
__basename instead of basename.
* conform/Makefile (test-xfail-POSIX2008/unistd.h/linknamespace):
Remove variable.
(test-xfail-XOPEN2K8/unistd.h/linknamespace): Likewise.
If you remove the "override CFLAGS += -Wno-uninitialized" in
math/Makefile, you get errors from lgamma implementations of the form:
../sysdeps/ieee754/dbl-64/e_lgamma_r.c: In function '__ieee754_lgamma_r':
../sysdeps/ieee754/dbl-64/e_lgamma_r.c:297:13: error: 'nadj' may be used uninitialized in this function [-Werror=maybe-uninitialized]
if(hx<0) r = nadj - r;
This is one of the standard kinds of false positive uninitialized
warnings: nadj is set under a certain condition, and then later used
under the same condition. This patch uses DIAG_* macros to suppress
the warning on the use of nadj. The ldbl-128 / ldbl-128ibm
implementation has a substantially different structure that avoids
this issue.
Tested for x86_64. (In fact this patch eliminates the need for that
-Wno-uninitialized on x86_64, but I want to test on more architectures
before removing it.)
* sysdeps/ieee754/dbl-64/e_lgamma_r.c: Include <libc-internal.h>.
(__ieee754_lgamma_r): Ignore uninitialized warnings around use of
NADJ.
* sysdeps/ieee754/flt-32/e_lgammaf_r.c: Include <libc-internal.h>.
(__ieee754_lgammaf_r): Ignore uninitialized warnings around use of
NADJ.
* sysdeps/ieee754/ldbl-96/e_lgammal_r.c: Include <libc-internal.h>.
(__ieee754_lgammal_r): Ignore uninitialized warnings around use of
NADJ.
If you remove the "override CFLAGS += -Wno-uninitialized" in
math/Makefile, one of the errors you get is:
../sysdeps/ieee754/dbl-64/mpa.c: In function '__mp_dbl.part.0':
../sysdeps/ieee754/dbl-64/mpa.c:183:5: error: 'c' may be used uninitialized in this function [-Werror=maybe-uninitialized]
c *= X[0];
The problem is that the p < 5 case initializes c if p is 1, 2, 3 or 4
but not otherwise, and in fact p is positive for all calls to this
function so the uninitialized case can't actually occur. This patch
replaces the "if (p == 4)" last case with a comment so the compiler
can see that all paths do initialize c.
Tested for x86_64.
* sysdeps/ieee754/dbl-64/mpa.c (norm): Remove if condition on
(p == 4) case.
This patch adds re_syntax_options (bug 18442) to the set of symbols
that are whitelisted in the linknamespace tests because, while the
references to them are genuine bugs that should be fixed, the
involvement of data symbols makes them harder to fix than most such
bugs.
Tested for x86_64 and x86.
* conform/linknamespace.pl (@whitelist): Add re_syntax_options.
* conform/Makefile (test-xfail-UNIX98/regex.h/linknamespace):
Remove variable.
(test-xfail-XOPEN2K/regex.h/linknamespace): Likewise.
(test-xfail-POSIX2008/regex.h/linknamespace): Likewise.
(test-xfail-XOPEN2K8/regex.h/linknamespace): Likewise.
This splits a considerable chunk of code from the main vfprintf
function. This will make it easier to remove the use of extend_alloca
from the positional argument handling code.
Remove use of ext.nsmap member of struct __res_state and always use
an identity mapping betwen the nsaddr_list array and the ext.nsaddrs
array. The fact that a nameserver has an IPv6 address is signalled by
setting nsaddr_list[].sin_family to zero.
The conform/ tests were using -D_POSIX_C_SOURCE=199912 to test "POSIX"
(1995/6). This patch changes them to use 199506L, the proper value
from the relevant edition of POSIX. (This doesn't make any difference
to features.h, but is the logically correct value to use.) Tested for
x86_64.
* conform/GlibcConform.pm ($CFLAGS{"POSIX"}): Use
-D_POSIX_C_SOURCE=199506L.
When cleaning up conformtest expectations for POSIX for locale.h in
<https://sourceware.org/ml/libc-alpha/2012-11/msg00382.html>, I missed
that locale.h had contents defined in POSIX.2:1993 as well as
POSIX.1:1995/6. Thus, LC_MESSAGES *should* in fact be required for
POSIX, because POSIX.2 says so; this patch adds that expectation
back. Tested for x86_64.
* conform/data/locale.h-data [POSIX] (LC_MESSAGES): Require.
This patch removes the specialized i386 assembly implementations for
fallocate{64}, pselect, and sync_file_range now that i386 have
support for 6 argument syscalls.
ldbl-96 remquol wrongly handles the case where the first argument is
finite and the second infinite, because the check for the second
argument being a NaN fails to disregard the explicit high mantissa bit
and so wrongly interprets an infinity as being a NaN. This patch
fixes this by masking off that bit, and improves test coverage for
both remainder and remquo (various cases were missing tests, or, as in
the case of the bug, were tested only for one of the two functions).
Tested for x86_64 and x86.
[BZ #18244]
* sysdeps/ieee754/ldbl-96/s_remquol.c (__remquol): Ignore explicit
high mantissa bit when testing whether P is a NaN.
* math/libm-test.inc (remainder_test_data): Add more tests.
(remquo_test_data): Likewise.
The i386 implementation of atanhl, for small arguments, does a
calculation that involves computing twice the square of the argument,
resulting in spurious underflows for some arguments. This patch fixes
this by just returning the argument when its exponent is below -32,
with underflow being forced as needed for subnormal arguments.
Tested for x86 and x86_64.
[BZ #18049]
* sysdeps/i386/fpu/e_atanhl.S (__ieee754_atanhl): For exponents
below -32, return the argument, with underflow if subnormal.
* math/auto-libm-test-in: Add more tests of atanh.
* math/auto-libm-test-out: Regenerated.
[BZ #17581] The checking chain of unused chunks was terminated by a hash of
the block pointer, which was sometimes confused with the chunk length byte.
We now avoid using a length byte equal to the magic byte.
When the malloc subsystem detects some kind of memory corruption,
depending on the configuration it prints the error, a backtrace, a
memory map and then aborts the process. In this process, the
backtrace() call may result in a call to malloc, resulting in
various kinds of problematic behavior.
In one case, the malloc it calls may detect a corruption and call
backtrace again, and a stack overflow may result due to the infinite
recursion. In another case, the malloc it calls may deadlock on an
arena lock with the malloc (or free, realloc, etc.) that detected the
corruption. In yet another case, if the program is linked with
pthreads, backtrace may do a pthread_once initialization, which
deadlocks on itself.
In all these cases, the program exit is not as intended. This is
avoidable by marking the arena that malloc detected a corruption on,
as unusable. The following patch does that. Features of this patch
are as follows:
- A flag is added to the mstate struct of the arena to indicate if the
arena is corrupt.
- The flag is checked whenever malloc functions try to get a lock on
an arena. If the arena is unusable, a NULL is returned, causing the
malloc to use mmap or try the next arena.
- malloc_printerr sets the corrupt flag on the arena when it detects a
corruption
- free does not concern itself with the flag at all. It is not
important since the backtrace workflow does not need free. A free
in a parallel thread may cause another corruption, but that's not
new
- The flag check and set are not atomic and may race. This is fine
since we don't care about contention during the flag check. We want
to make sure that the malloc call in the backtrace does not trip on
itself and all that action happens in the same thread and not across
threads.
I verified that the test case does not show any regressions due to
this patch. I also ran the malloc benchmarks and found an
insignificant difference in timings (< 2%).
* malloc/Makefile (tests): New test case tst-malloc-backtrace.
* malloc/arena.c (arena_lock): Check if arena is corrupt.
(reused_arena): Find a non-corrupt arena.
(heap_trim): Pass arena to unlink.
* malloc/hooks.c (malloc_check_get_size): Pass arena to
malloc_printerr.
(top_check): Likewise.
(free_check): Likewise.
(realloc_check): Likewise.
* malloc/malloc.c (malloc_printerr): Add arena argument.
(unlink): Likewise.
(munmap_chunk): Adjust.
(ARENA_CORRUPTION_BIT): New macro.
(arena_is_corrupt): Likewise.
(set_arena_corrupt): Likewise.
(sysmalloc): Use mmap if there are no usable arenas.
(_int_malloc): Likewise.
(__libc_malloc): Don't fail if arena_get returns NULL.
(_mid_memalign): Likewise.
(__libc_calloc): Likewise.
(__libc_realloc): Adjust for additional argument to
malloc_printerr.
(_int_free): Likewise.
(malloc_consolidate): Likewise.
(_int_realloc): Likewise.
(_int_memalign): Don't touch corrupt arenas.
* malloc/tst-malloc-backtrace.c: New test case.
The conditional that evaluates if there are any FAILed test cases
currently always fails, since we ensure it fails if we find any
unexpected results in tests.sum and it would obviously fail if it does
not find failed results in tests.sum. This patch fixes this by simply
inverting the result of the egrep, i.e. succeed if egrep fails (to
find failed results) and fail if it succeeds.
Tested with 'make subdirs=localedata check' and 'make subdirs=locale
check' where all tests succeed and with 'make subdirs=elf check' where
a couple of tests fail for me.
* Makefile (summarize-tests): Fix return value on success.
I was told that Ma Shimao submitted a patch to add envz_remove to the
libc manual, but the patch could not be accepted since he does not
have a copyright assignment in place. I have been woefully behind on
libc-alpha recently and have not seen the patch or the discussion
thread. I have also not read the man page for envz_remove, so
Alexandre Oliva asked me if I could write this independently and post
a patch. The patch below is the result of the same - I have written
it based on the implementation in string/envz.c and Alex told me via
email that the function is AS, AC and MT-safe like envz_strip.
I assume Alex and Carlos cannot review this since they have been
tainted by the original patch (I haven't even tried to look for a link
to it since I don't want to be tainted) so someone else will have to
review this. If there are no reviewers till the end of the week, I
will commit this since I believe there is a chance that there are no
other reviewers who haven't read that thread.
* manual/string.texi (Envz Functions): Add envz_remove.
While trying to get nptl/tst-initializers1.c to include the test skeleton, I
came across a couple of speed bumps. Firstly: after making the appropriate
changes to the test, running `make check' led to this error:
> In file included from ../malloc/malloc.h:24:0,
..
> from tst-initializers1.c:60:
> ../include/stdio.h:111:1: error: unknown type name `wint_t'
> extern wint_t __getwc_unlocked (FILE *__fp);
So, `wint_t' is used before being defined. Question: Why did test-skeleton.c
not cause this error in any of the other tests that include it?
Anyway, I noticed include/stdio.h includes stddef.h, which in turn defines
`wint_t', but only if `__need_wint_t' is defined. So I put in a
`#define __need_wint_t' before the include to get rid of the error. Is that
the correct fix?
A subsequent `make && make check' led to this second error:
> from tst-initializers1-c89.c:1:
> ../test-skeleton.c: In function `main':
> ../test-skeleton.c:356:11: error: `for' loop initial declarations are only
> allowed in C99 mode
> for (struct temp_name_list *n = temp_name_list;
Although there seem to be several other C89 no-noes in test-skeleton.c, I
needed only to fix this specific one for gcc-4.8.3 to stop complaining.
Both bo_CN and bo_IN were not compiling. The following fix
gets them into a usable state again giving a clean build
result for `make localedata/install-locales`.
Similar to various other bugs in this area, some atanh implementations
do not raise the underflow exception for subnormal arguments, when the
result is tiny and inexact. This patch forces the exception in a
similar way to previous fixes. (No change in this regard is needed
for the i386 implementation; special handling to force underflows in
these cases will only be needed there when the spurious underflows,
bug 18049, get fixed.)
Tested for x86_64, x86, powerpc and mips64.
[BZ #16352]
* sysdeps/i386/fpu/e_atanh.S (dbl_min): New object.
(__ieee754_atanh): Force underflow exception for results with
small absolute value.
* sysdeps/i386/fpu/e_atanhf.S (flt_min): New object.
(__ieee754_atanhf): Force underflow exception for results with
small absolute value.
* sysdeps/ieee754/dbl-64/e_atanh.c: Include <float.h>.
(__ieee754_atanh): Force underflow exception for results with
small absolute value.
* sysdeps/ieee754/flt-32/e_atanhf.c: Include <float.h>.
(__ieee754_atanhf): Force underflow exception for results with
small absolute value.
* sysdeps/ieee754/ldbl-128/e_atanhl.c: Include <float.h>.
(__ieee754_atanhl): Force underflow exception for results with
small absolute value.
* sysdeps/ieee754/ldbl-128ibm/e_atanhl.c: Include <float.h>.
(__ieee754_atanhl): Force underflow exception for results with
small absolute value.
* sysdeps/ieee754/ldbl-96/e_atanhl.c: Include <float.h>.
(__ieee754_atanhl): Force underflow exception for results with
small absolute value.
* math/auto-libm-test-in: Do not allow missing underflow
exceptions from atanh.
* math/auto-libm-test-out: Regenerated.
The flt-32 implementation of tanf produces spurious underflow
exceptions for some small arguments, through computing values on the
order of x^5. This patch fixes this by adjusting the threshold for
returning x (or, as applicable, +/- 1/x) to 2**-13 (the next term in
the power series being x^3/3).
Tested for x86_64 and x86.
[BZ #18221]
* sysdeps/ieee754/flt-32/k_tanf.c (__kernel_tanf): Use 2**-13 not
2**-28 as threshold for returning x or +/- 1/x.
* math/auto-libm-test-in: Add more tests of tan.
* math/auto-libm-test-out: Regenerated.
The flt-32 implementation of lgammaf produces spurious underflow
exceptions for some large arguments, because of calculations involving
x^-2 multiplied by small constants. This patch fixes this by
adjusting the threshold for a simpler computation to 2**26 (the error
in the simpler computation is on the order of 0.5 * log (x), for a
result on the order of x * log (x)).
Tested for x86_64 and x86.
[BZ #18220]
* sysdeps/ieee754/flt-32/e_lgammaf_r.c (__ieee754_lgammaf_r): Use
2**26 not 2**58 as threshold for returning x * (log (x) - 1).
* math/auto-libm-test-in: Add another test of lgamma.
* math/auto-libm-test-out: Regenerated.
The flt-32 implementation of erfcf produces spurious underflow
exceptions for some arguments close to 0, because of calculations
squaring the argument and then multiplying by small constants. This
patch fixes this by adjusting the threshold for arguments for which
the result is so close to 1 that 1 - x will give the right result from
2**-56 to 2**-26. (If 1 - x * 2/sqrt(pi) were used, the errors would be
on the order of x^3 and a much larger threshold could be used.)
Tested for x86_64 and x86.
[BZ #18217]
* sysdeps/ieee754/flt-32/s_erff.c (__erfcf): Use 2**-26 not 2**-56
as threshold for returning 1 - x.
* math/auto-libm-test-in: Add more tests of erfc.
* math/auto-libm-test-out: Regenerated.
The sysdeps/ieee754/flt-32 version of atanf produces spurious
underflow exceptions for some large arguments, because of computations
that compute x^-4. This patch fixes this by adjusting the threshold
for large arguments (for which +/- pi/2 can just be returned, the
correct result being roughly +/- pi/2 - 1/x) from 2^34 to 2^25.
Tested for x86_64 and x86.
[BZ #18196]
* sysdeps/ieee754/flt-32/s_atanf.c (__atanf): Use 2^25 not 2^34 as
threshold for large arguments.
* math/auto-libm-test-in: Add another test of atan.
* math/auto-libm-test-out: Regenerated.
Similar to various other bugs in this area, some log1p implementations
do not raise the underflow exception for subnormal arguments, when the
result is tiny and inexact. This patch forces the exception in a
similar way to previous fixes. (The ldbl-128ibm implementation
doesn't currently need any change as it already generates this
exception, albeit through code that would generate spurious exceptions
in other cases; special code for this issue will only be needed there
when fixing the spurious exceptions.)
Tested for x86_64, x86, powerpc and mips64.
[BZ #16339]
* sysdeps/i386/fpu/s_log1p.S (dbl_min): New object.
(__log1p): Force underflow exception for results with small
absolute value.
* sysdeps/i386/fpu/s_log1pf.S (flt_min): New object.
(__log1pf): Force underflow exception for results with small
absolute value.
* sysdeps/ieee754/dbl-64/s_log1p.c: Include <float.h>.
(__log1p): Force underflow exception for results with small
absolute value.
* sysdeps/ieee754/flt-32/s_log1pf.c: Include <float.h>.
(__log1pf): Force underflow exception for results with small
absolute value.
* sysdeps/ieee754/ldbl-128/s_log1pl.c: Include <float.h>.
(__log1pl): Force underflow exception for results with small
absolute value.
* math/auto-libm-test-in: Do not allow missing underflow
exceptions from log1p.
* math/auto-libm-test-out: Regenerated.
