the _CS_V6_ENV and _CS_V7_ENV constants are required to be available for use
with confstr. glibc defines these constants with values 1148 and 1149,
respectively.
the only missing (and required) confstr constants are
_CS_POSIX_V7_THREADS_CFLAGS and _CS_POSIX_V7_THREADS_LDFLAGS which remain
unavailable in glibc.
aarch64, arm, mips, mips64, mipsn32, powerpc, powerpc64 and sh have
cpu feature bits defined in linux for AT_HWCAP auxv entry, so expose
those in sys/auxv.h
it seems the mips hwcaps were never exposed to userspace neither
by linux nor by glibc, but that's most likely an oversight.
since cpu sets can be dynamically allocated and have variable size,
accessing their contents via ->__bits is not valid; performing pointer
arithmetic outside the range of the size of the declared __bits array
results in undefined beahavior. instead, only use cpu_set_t for
fixed-size cpu set objects (instantiated by the caller) and as an
abstract pointer type for dynamically allocated ones. perform all
accesses simply by casting the abstract pointer type cpuset_t * back
to unsigned long *.
this reverts commit 2c1f8fd5da. without
the _Noreturn attribute, the compiler cannot use asserts to perform
reachability/range analysis. this leads to missed optimizations and
spurious warnings.
the original backtrace problem that prompted the removal of _Noreturn
was not clearly documented at the time, but it seems to happen only
when libc was built without -g, which also breaks many other
backtracing cases.
modern compilers (for gcc, versions 4.8 and later) automatically
pre-include <stdc-predef.h> to obtain the values of certain predefined
macros specified by ISO C but which reflect properties of the library
implementation, not just the compiler. provide values indicating that
wchar_t is Unicode-encoded and that Annex F (IEEE floating point) is
supported unless the compiler indicates otherwise.
based on patch by Masanori Ogino.
it was changed to EM_OR1K in 200d15479c
as that was meant to be the official name, but glibc and the latest
gabi spec still uses the EM_OPENRISC name:
http://www.sco.com/developers/gabi/latest/ch4.eheader.html
binutils defines both macros so we should do the same for backward
compatibility.
placing the opening brace on the same line as the struct keyword/tag
is the style I prefer and seems to be the prevailing practice in more
recent additions.
these changes were generated by the command:
find include/ arch/*/bits -name '*.h' \
-exec sed -i '/^struct [^;{]*$/{N;s/\n/ /;}' {} +
and subsequently checked by hand to ensure that the regex did not pick
up any false positives.
the kernel ABI value for RUSAGE_CHILDREN is -1, not 1. the latter is
actually interpreted as RUSAGE_THREAD, to obtain values for just the
calling thread and not the whole process.
compilers are free not to copy, or in some cases to clobber, padding
bytes in a structure. while it's an aliasing violation, and thus
undefined behavior, to copy or manipulate other sockaddr types using
sockaddr_storage, it seems likely that traditional code attempts to do
so, and the original intent of the sockaddr_storage structure was
probably to allow such usage.
in the interest of avoiding silent and potentially dangerous breakage,
ensure that there are no actual padding bytes in sockaddr_storage by
moving and adjusting the size of the __ss_padding member so that it
fits exactly.
this change also removes a silent assumption that the alignment of
long is equal to its size.
kernel connection multiplexor macros AF_KCM, PF_KCM, SOL_KCM were
added in linux commit ab7ac4eb9832e32a09f4e8042705484d2fb0aad3
MSG_BATCH sendmsg flag for performance optimization was added
in linux commit f092276d85b82504e8a07498f4e9e0c51f06745c
SOL_* macros are now synced with linux socket.h which is not a uapi
header and glibc did not have the macros either, but that has changed
http://sourceware.org/ml/libc-alpha/2016-05/msg00322.html
new fields and associated linux commit:
tcpi_notsent_bytes, tcpi_min_rtt cd9b266095f422267bddbec88f9098b48ea548fc
tcpi_data_segs_in, tcpi_data_segs_out a44d6eacdaf56f74fad699af7f4925a5f5ac0e7f
new socket option so application can give advice about routing
path quality of connected udp sockets, added in linux commit
a87cb3e48ee86d29868d3f59cfb9ce1a8fa63314
previously, the only way the stopping condition could be met with
correct lengths in the headers invoked undefined behavior, adding
sizeof(struct cmsghdr) beyond the end of the cmsg buffer.
instead, compute and compare sizes rather than pointers.
allows the os to free the marked pages lazily on memory pressure.
expected to increase malloc performance.
new in linux commit 854e9ed09dedf0c19ac8640e91bcc74bc3f9e5c9
new flag for exclusive wakeup mode when an event source fd is attached
to multiple epoll fds but they should not all receive the events.
new in linux commit df0108c5da561c66c333bb46bfe3c1fc65905898
new socket options for setting classic or extended BPF program
for sockets in a SO_REUSEPORT group. added in linux commit
538950a1b7527a0a52ccd9337e3fcd304f027f13
currently five targets use the same mman.h constants and the rest
share most constants too, so move them to sys/mman.h before the
bits/mman.h include where the differences can be corrected by
redefinition of the macros.
this fixes two minor bugs: POSIX_MADV_DONTNEED was wrong on most
targets (it should be the same as MADV_DONTNEED), and sh defined
the x86-only MAP_32BIT mmap flag.
Daniel Sabogal
Felix Janda
Szabolcs Nagy
Rich Felker
Duncan Overbruck
Bobby Bingham
Nathan Zadoks