The lgamma (and likewise lgammaf, lgammal) function wrongly sets the
signgam variable even when building for strict ISO C conformance
(-std=c99 / -std=c11), although the user may define such a variable
and it's only in the implementation namespace for POSIX with XSI
extensions enabled.
Following discussions starting at
<https://sourceware.org/ml/libc-alpha/2013-04/msg00767.html> and
<https://sourceware.org/ml/libc-alpha/2015-10/msg00844.html>, it seems
that the safest approach for fixing this particular issue is for
signgam to become a weak alias for a newly exported symbol __signgam,
with the library functions only setting __signgam, at which point
static linker magic will preserve the alias for newly linked binaries
that refer to the library's signgam rather than defining their own,
while breaking the alias for programs that define their own signgam,
with new symbol versions for lgamma functions and with compat symbols
for existing binaries that set both signgam and __signgam.
This patch implements that approach for the fix. signgam is made into
a weak alias. The four symbols __signgam, lgamma, lgammaf, lgammal
get new symbol versions at version GLIBC_2.23, with the existing
versions of lgamma, lgammaf and lgammal becoming compat symbols.
When the compat versions are built, gamma, gammaf and gammal are
aliases for the compat versions (i.e. always set signgam); this is OK
as they are not ISO C functions, and avoids adding new symbol versions
for them unnecessarily. When the compat versions are not built
(i.e. for static linking and for future glibc ports), gamma, gammaf
and gammal are aliases for the new versions that set __signgam. The
ldbl-opt versions are updated accordingly.
The lgamma wrappers are adjusted so that the same source files,
included from different files with different definitions of
USE_AS_COMPAT, can build either the new versions or the compat
versions. Similar changes are made to the ia64 versions (untested).
Tests are added that the lgamma functions do not interfere with a user
variable called signgam for ISO C, with various choices for the size
of that variable, whether it is initialized, and for static and
dynamic linking. The conformtest whitelist entry is removed as well.
Tested for x86_64, x86, mips64 and powerpc, including looking at
objdump --dynamic-syms output to make sure the expected sets of
symbols were aliases. Also spot-tested that a binary built with old
glibc works properly (i.e. gets signgam set) when run with new glibc.
[BZ #15421]
* sysdeps/ieee754/s_signgam.c (signgam): Rename to __signgam,
initialize with 0 and define as weak alias of __signgam.
* include/math.h [!_ISOMAC] (__signgam): Declare.
* math/Makefile (libm-calls): Add w_lgamma_compat.
(tests): Add test-signgam-uchar, test-signgam-uchar-init,
test-signgam-uint, test-signgam-uint-init, test-signgam-ullong and
test-signgam-ullong-init.
(tests-static): Add test-signgam-uchar-static,
test-signgam-uchar-init-static, test-signgam-uint-static,
test-signgam-uint-init-static, test-signgam-ullong-static and
test-signgam-ullong-init-static.
(CFLAGS-test-signgam-uchar.c): New variable.
(CFLAGS-test-signgam-uchar-init.c): Likewise.
(CFLAGS-test-signgam-uchar-static.c): Likewise.
(CFLAGS-test-signgam-uchar-init-static.c): Likewise.
(CFLAGS-test-signgam-uint.c): Likewise.
(CFLAGS-test-signgam-uint-init.c): Likewise.
(CFLAGS-test-signgam-uint-static.c): Likewise.
(CFLAGS-test-signgam-uint-init-static.c): Likewise.
(CFLAGS-test-signgam-ullong.c): Likewise.
(CFLAGS-test-signgam-ullong-init.c): Likewise.
(CFLAGS-test-signgam-ullong-static.c): Likewise.
(CFLAGS-test-signgam-ullong-init-static.c): Likewise.
* math/Versions (libm): Add GLIBC_2.23.
* math/lgamma-compat.h: New file.
* math/test-signgam-main.c: Likewise.
* math/test-signgam-uchar-init-static.c: Likewise.
* math/test-signgam-uchar-init.c: Likewise.
* math/test-signgam-uchar-static.c: Likewise.
* math/test-signgam-uchar.c: Likewise.
* math/test-signgam-uint-init-static.c: Likewise.
* math/test-signgam-uint-init.c: Likewise.
* math/test-signgam-uint-static.c: Likewise.
* math/test-signgam-uint.c: Likewise.
* math/test-signgam-ullong-init-static.c: Likewise.
* math/test-signgam-ullong-init.c: Likewise.
* math/test-signgam-ullong-static.c: Likewise.
* math/test-signgam-ullong.c: Likewise.
* math/w_lgamma.c: Rename to w_lgamma_main.c and replace by
wrapper of w_lgamma_main.c.
* math/w_lgamma_compat.c: New file.
* math/w_lgamma_compatf.c: Likewise.
* math/w_lgamma_compatl.c: Likewise.
* math/w_lgamma_main.c: New file. Based on w_lgamma.c. Include
<lgamma-compat.h>. Condition contents on [BUILD_LGAMMA]. Support
defining compatibility symbols.
(__lgamma): Change to LGFUNC (__lgamma). Use CALL_LGAMMA.
* math/w_lgammaf.c: Rename to w_lgammaf_main.c and replace by
wrapper of w_lgammaf_main.c.
* math/w_lgammaf_main.c: New file. Based on w_lgammaf.c. Include
<lgamma-compat.h>. Condition contents on [BUILD_LGAMMA]. Support
defining compatibility symbols.
(__lgammaf): Change to LGFUNC (__lgammaf). Use CALL_LGAMMA.
* math/w_lgammal.c: Rename to w_lgammal_main.c and replace by
wrapper of w_lgammal_main.c.
* math/w_lgammal_main.c: New file. Based on w_lgammal.c. Include
<lgamma-compat.h>. Condition contents on [BUILD_LGAMMA]. Support
defining compatibility symbols.
(__lgammal): Change to LGFUNC (__lgammal). Use CALL_LGAMMA.
* sysdeps/ia64/fpu/lgamma-compat.h: New file.
* sysdeps/ia64/fpu/w_lgamma.c: Move to ....
* sysdeps/ia64/fpu/w_lgamma_main.c: ...here. Include
<lgamma-compat.h>.
(__ieee754_lgamma): Change to LGFUNC (lgamma). Use CALL_LGAMMA.
(__ieee754_gamma): Define as alias.
* sysdeps/ia64/fpu/w_lgammaf.c: Move to ....
* sysdeps/ia64/fpu/w_lgammaf_main.c: ...here. Include
<lgamma-compat.h>.
(__ieee754_lgammaf): Change to LGFUNC (lgammaf). Use CALL_LGAMMA.
(__ieee754_gammaf): Define as alias.
* sysdeps/ia64/fpu/w_lgammal.c: Move to ....
* sysdeps/ia64/fpu/w_lgammal_main.c: ...here. Include
<lgamma-compat.h>.
(__ieee754_lgammal): Change to LGFUNC (lgammal). Use CALL_LGAMMA.
(__ieee754_gammal): Define as alias.
* sysdeps/ieee754/ldbl-opt/w_lgamma.c: Move to ....
* sysdeps/ieee754/ldbl-opt/w_lgamma_compat.c: ...here. Include
<math/w_lgamma_compat.c>.
[LONG_DOUBLE_COMPAT(libm, GLIBC_2_0)] (__lgammal_dbl_compat):
Define as alias of __lgamma_compat and use in defining lgammal.
* sysdeps/ieee754/ldbl-opt/w_lgammal.c: Move to ....
* sysdeps/ieee754/ldbl-opt/w_lgamma_compatl.c: ...here. Include
<math/lgamma-compat.h> and <math/w_lgamma_compatl.c>.
(USE_AS_COMPAT): New macro.
(LGAMMA_OLD_VER): Undefine and redefine.
(lgammal): Do not define here.
(gammal): Only define here if [GAMMA_ALIAS].
* conform/linknamespace.pl (@whitelist): Remove signgam.
* sysdeps/nacl/libm.abilist: Update.
* sysdeps/unix/sysv/linux/aarch64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/alpha/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/arm/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/hppa/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/i386/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/ia64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/m68k/coldfire/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/m68k/m680x0/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/microblaze/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/mips/mips32/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/mips/mips64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/nios2/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libm.abilist:
Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libm.abilist:
Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc64/libm-le.abilist:
Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc64/libm.abilist:
Likewise.
* sysdeps/unix/sysv/linux/s390/s390-32/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/s390/s390-64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/sh/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc32/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/tile/tilegx/tilegx32/libm.abilist:
Likewise.
* sysdeps/unix/sysv/linux/tile/tilegx/tilegx64/libm.abilist:
Likewise.
* sysdeps/unix/sysv/linux/tile/tilepro/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/x86_64/64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/x86_64/x32/libm.abilist: Likewise.
The new format lists the version on each line, as in:
VERSION SYMBOL TYPE [VALUE]
This makes it easier to process the files with line-oriented tools.
The abilist files were converted with this awk script:
/^[^ ]/ { version = $1 }
/^ / { print version, substr($0, 2) }
And sorted under the "C" locale with sort.
This patch added a new fmemopen version, for glibc 2.22, that aims to be
POSIX complaint. It fixes some long-stading glibc fmemopen issues, such
as:
* it changes the way fseek with SEEK_END works on fmemopen to seek
relative to buffer size instead of first '\0'. This is default mode and
'b' opening mode does not change internal behavior (bz#6544).
* fix apending opening mode to use as start position either first null
byte of len specified in function call (bz#13152 and #13151).
* remove binary option 'b' and internal different handling (bz#12836)
* fix seek/SEE_END with negative values (bz#14292).
A compatibility symbol is provided to with old behavior for older symbols
version (2.2.5).
* include/stdio.h (fmemopen): Remove hidden prototype.
(__fmemopen): Add new hidden prototype.
* libio/Makefile: Add oldfmemopen object.
* libio/Versions [GLIBC_2.22]: Add new fmemopen symbol.
* libio/fmemopen.c (__fmemopen): Function rewrite to be POSIX
compliance.
* libio/oldfmemopen.c: New file: old fmemopen implementation for
symbol compatibility.
* stdio-common/Makefile [tests]: Add new tst-fmemopen3.
* stdio-common/psiginfo.c [psiginfo]: Call __fmemopen instead of
fmemopen.
* stdio-common/tst-fmemopen3.c: New file: more fmemopen tests, focus
on append and read mode.
* sysdeps/unix/sysv/linux/aarch64/libc.abilist [GLIBC_2.22]: Add
fmemopen.
* sysdeps/unix/sysv/linux/alpha/libc.abilist [GLIBC_2.22]: Likewise.
* sysdeps/unix/sysv/linux/arm/libc.abilist [GLIBC_2.22]: Likewise.
* sysdeps/unix/sysv/linux/i386/libc.abilist [GLIBC_2.22]: Likewise.
* sysdeps/unix/sysv/linux/ia64/libc.abilist [GLIBC_2.22]:
Likewise.
* sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist
[GLIBC_2.22]: Likewise.
* sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist [GLIBC_2.22]:
Likewise.
* sysdeps/unix/sysv/linux/microblaze/libc.abilist [GLIBC_2.22]:
Likewise.
* sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist
[GLIBC_2.22]: Likewise.
* sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist
[GLIBC_2.22]: Likewise.
* sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist
[GLIBC_2.22]: Likewise.
* sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist
[GLIBC_2.22]: Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist
[GLIBC_2.22]: Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist
[GLIBC_2.22]: Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc64/libc.abilist
[GLIBC_2.22]: Likewise.
* sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist [GLIBC_2.22]:
Likewise.
* sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist [GLIBC_2.22]:
Likewise.
* sysdeps/unix/sysv/linux/sh/libc.abilist [GLIBC_2.22]: Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist
[GLIBC_2.22]: Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist
[GLIBC_2.22]: Likewise.
* sysdeps/unix/sysv/linux/tile/tilegx/tilegx32/libc.abilist
[GLIBC_2.22]: Likewise.
* sysdeps/unix/sysv/linux/tile/tilegx/tilegx64/libc.abilist
[GLIBC_2.22]: Likewise.
* sysdeps/unix/sysv/linux/tile/tilepro/libc.abilist [GLIBC_2.22]:
Likewise.
* sysdeps/unix/sysv/linux/x86_64/64/libc.abilist [GLIBC_2.22]:
Likewise.
* sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist [GLIBC_2.22]:
Likewise.
* sysdeps/unix/sysv/linux/hppa/libc.abilist [GLIBC_2.22]: Likewise.
* sysdeps/unix/sysv/linux/nios2/libc.abilist [GLIBC_2.22]: Likewise.
This patch enables syscalls.list entries to specify both compat and
non-compat symbol versions for the same syscall definition, making use
of this for setrlimit / chown / lchown where the inability to specify
such aliases showed up in the course of work on bug 14138.
The change to make-syscalls.sh is minimal: adding a SHARED conditional
on the compat_symbol calls. It remains the case that if a compat
symbol version is specified, the syscall is only built for the shared
library at all if an explicit symbol version is given for a non-compat
symbol (so it's necessary to specify "lchown@@GLIBC_2.0
chown@GLIBC_2.0" rather than just "lchown chown@GLIBC_2.0"). It also
remains the case, as already commented in make-syscalls.sh, that no
SHLIB_COMPAT conditionals are generated, so there would be problems if
the same syscalls.list file, with compat symbols, were used for both
configurations that should have those symbols and configurations for
which they should be conditioned out with SHLIB_COMPAT.
Tested for x86.
* sysdeps/unix/make-syscalls.sh (emit_weak_aliases): Condition
compat_symbol calls on [SHARED].
* sysdeps/unix/sysv/linux/powerpc/lchown.S: Remove file.
* sysdeps/unix/sysv/linux/i386/syscalls.list (oldsetrlimit):
Remove.
(setrlimit): Add setrlimit@GLIBC_2.0 alias.
* sysdeps/unix/sysv/linux/m68k/m680x0/syscalls.list
(oldsetrlimit): Remove.
(setrlimit): Add setrlimit@GLIBC_2.0 alias.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/syscalls.list
(lchown): New syscall entry.
(oldsetrlimit): Remove.
(setrlimit): Add setrlimit@GLIBC_2.0 alias.
* sysdeps/unix/sysv/linux/s390/s390-32/syscalls.list
(oldsetrlimit): Remove.
(setrlimit): Add setrlimit@GLIBC_2.0 alias.
Bug 14138 is followup cleanup after removal of support for old Linux
kernel versions: moving syscalls to syscalls.list where the only
reason for using C definitions was kernel version conditionals that
are no longer present.
This patch deals with the case of setrlimit
(sysdeps/unix/sysv/linux/i386/setrlimit.c, included by various other
architectures). Where needed (where there is also a compat symbol for
setrlimit@GLIBC_2.0), new syscalls.list entries are added. Where not
needed (where there is no such compat symbol and the minimum symbol
version for libc is 2.2 or later), no such entries are added as that
in sysdeps/unix/syscalls.list will suffice. Thus arm and sh need no
such entries, while m68k and powerpc need entries only in a
subdirectory syscalls.list file rather than for all configurations
that previously used setrlimit.c.
(setrlimit@@GLIBC_2.2 and setrlimit@GLIBC_2.0 are now semantically
identical - the new symbol version was about a change of types from
signed to unsigned and the former compatibility code for dealing with
large unsigned arguments on old kernels is no longer needed or
present, having been removed with support for pre-2.4 kernels.
However, making the two versions into aliases doesn't work at present:
the case of having both default and non-default symbol versions on the
same syscalls.list line results in a compat_symbol call in code built
for static libc, which doesn't compile. I don't suppose it would be
hard to generate SHARED conditionals from make-syscalls.sh to fix
this, but in any case this patch doesn't make things any worse, as the
functions weren't aliases before the patch either.)
Tested for x86, and ran ABI tests for ARM as an example of an
architecture where the setrlimit.c file was just removed without
adding syscalls.list entries.
[BZ #14138]
* sysdeps/unix/sysv/linux/arm/setrlimit.c: Remove file.
* sysdeps/unix/sysv/linux/i386/setrlimit.c: Likewise.
* sysdeps/unix/sysv/linux/m68k/setrlimit.c: Likewise.
* sysdeps/unix/sysv/linux/powerpc/setrlimit.c: Likewise.
* sysdeps/unix/sysv/linux/s390/s390-32/setrlimit.c: Likewise.
* sysdeps/unix/sysv/linux/sh/setrlimit.c: Likewise.
* sysdeps/unix/sysv/linux/i386/syscalls.list (setrlimit): Add
syscall entry for GLIBC_2.2 symbol version.
* sysdeps/unix/sysv/linux/m68k/m680x0/syscalls.list (setrlimit):
Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/syscalls.list
(setrlimit): Likewise.
* sysdeps/unix/sysv/linux/s390/s390-32/syscalls.list (setrlimit):
Likewise.
