NT_MIPS_FP_MODE is new in linux commit
1ae22a0e35636efceab83728ba30b013df761592
NT_MIPS_DSP is new in linux commit
44109c60176ae73924a42a6bef64ef151aba9095
new fields for RFC 4898 tcp stats in linux
tcpi_bytes_sent added in commit ba113c3aa79a7f941ac162d05a3620bdc985c58d
tcpi_bytes_retrans added in commit fb31c9b9f6c85b1bad569ecedbde78d9e37cd87b
tcpi_dsack_dups added in commit 7e10b6554ff2ce7f86d5d3eec3af5db8db482caa
tcpi_reord_seen added in commit 7ec65372ca534217b53fd208500cf7aac223a383
The new fields change the size of a public struct and thus an ABI break,
but this is how the getsockopt TCP_INFO api is designed: the tcp_info
type must only be used with a length parameter in extern interfaces.
inotify_add_watch flag to prevent modifying existing watch descriptors,
when used on an already watched inode it fails with EEXIST.
added in linux commit 4d97f7d53da7dc830dbf416a3d2a6778d267ae68
On s390x, POSIX_FADV_DONTNEED and POSIX_FADV_NOREUSE have different
values than on all other architectures that Linux supports.
Handle this difference by wrapping their definitions in
include/fcntl.h in #ifdef, so that arch/s390x/bits/fcntl.h can
override them.
as noted in Austin Group issue #1236, the XSI shading for TSVTX is
misplaced in the html version of the standard; it was only supposed to
be on the description text. the intent was that the definition always
be visible, which is reflected in the pdf version of the standard.
this reverts commits d93c0740d8 and
729fef0a93.
C11 removed the requirement that FILE be a complete type, which was
deemed erroneous, as part of the changes introduced by N1439 regarding
completeness of types (see footnote 6 for specific mention of FILE).
however the current version of POSIX is still based on C99 and
incorporates the old requirement that FILE be a complete type.
expose an arbitrary, useless complete type definition because the
actual object used to represent FILE streams cannot be public/ABI.
thanks to commit 13d1afa46f, we now have
a framework for suppressing the public complete-type definition of FILE
when stdio.h is included internally, so that a different internal
definition can be provided. this is perfectly well-defined, since the
same struct tag can refer to different types in different translation
units. it would be a problem if the implementation were accessing the
application's FILE objects or vice versa, but either would be
undefined behavior.
the motivation for this change is twofold. first, it gets the fallback
logic out of the dynamic linker, improving code readability and
organization. second, it provides application code that wants to use
the membarrier syscall, which depends on preregistration of intent
before the process becomes multithreaded unless unbounded latency is
acceptable, with a symbol that, when linked, ensures that this
registration happens.
new in linux commit 76b7f670730e87974f71df9f6129811e2769666e
in struct signalfd_siginfo the pad member is changed to __pad to keep
the namespace clean, it's not part of the public api.
add UDP_NO_CHECK6_* to restrict zero UDP6 checksums, new in linux commit
1c19448c9ba6545b80ded18488a64a7f3d8e6998 (pre-v4.18 change, was missed)
add UDP_SEGMENT to support generic segmentation offload for udp datagrams,
bec1f6f697362c5bc635dacd7ac8499d0a10a4e7 (new in v4.18)
add packet delivery info to tcp_info,
new in linux commit feb5f2ec646483fb66f9ad7218b1aad2a93a2a5c
add TCP_ZEROCOPY_RECEIVE socket option for zerocopy receive,
new in linux commit 05255b823a6173525587f29c4e8f1ca33fd7677d
add TCP_INQ socket option and TCP_CM_INQ cmsg to get in-queue bytes in cmsg
upon read, new in linux commit b75eba76d3d72e2374fac999926dafef2997edd2
add TCP_REPAIR_* to fix repair socket window probe patch,
new in linux commit 31048d7aedf31bf0f69c54a662944632f29d82f2
revert commit a603a75a72.
as a result of commit 1c84c99913 this is
now safe, assuming an interpretation of the somewhat-underspecified
attribute((const)) consistent with real-world usage.
previously, a common __posix_spawnx backend was used that accepted an
additional argument for the execve variant to call in the child. this
moderately bloated up the posix_spawn function, shuffling arguments
between stack and/or registers to call a 7-argument function from a
6-argument one.
instead, tuck the exec function pointer in an unused part of the
(large) pthread_spawnattr_t structure, and have posix_spawnp duplicate
the attributes and fill in a pointer to __execvpe. the net code size
change is minimal, but the weight is shifted to the "heavier" function
which already pulls in more dependencies.
as a bonus, we get rid of an external symbol (__posix_spawnx) that had
no really good place for a declaration because it shouldn't have
existed to begin with.
commit 201995f382 introduced a hack
utilizing the signedness of character constants at the preprocessor
level to avoid depending on the gcc-specific __CHAR_UNSIGNED__ predef.
while this trick works on gcc and presumably other compilers being
used, it's not clear that the behavior it depends on is actually
conforming. C11 6.4.4.4 ¶10 defines character constants as having type
int, and 6.10.1 ¶4 defines preprocessor #if arithmetic to take place
in intmax_t or uintmax_t, depending on the signedness of the integer
operand types, and it is specified that "this includes interpreting
character constants".
if character literals had type char and just promoted to int, it would
be clear that when char is unsigned they should behave as uintmax_t at
the preprocessor level. however, as written the text of the standard
seems to require that character constants always behave as intmax_t,
corresponding to int, at the preprocessor level.
since there is a good deal of ambiguity about the correct behavior and
a risk that compilers will disagree or that an interpretation may
mandate a change in the behavior, do not rely on it for defining
CHAR_MIN and CHAR_MAX correctly. instead, use the signedness of the
value (as opposed to the type) of '\xff', which will be positive if
and only if plain char is unsigned. this behavior is clearly
specified, and the specific case '\xff' is even used in an example,
under 6.4.4.4 of the standard.
commit 98c9af5001 wrongly claimed they
do not need to be valid for such usage, but the last sentence of C11
7.1.4 ¶1 imposes a broad requirement that all macros specified as
integer constant expressions also need to be valid for #if.
simply write the value out explicitly. there is no value here in
pretending that the width of int will vary.
POSIX requires the symlink function to fail with ENAMETOOLONG if the
link contents to be written exceed SYMLINK_MAX in length, but neither
Linux nor our syscall wrapper code enforce this. the value 255 for
SYMLINK_MAX is not meaningful and does not seem to have been motivated
by anything except perhaps a wrong assumption that a definition was
mandatory. it has been present (though moving through bits to
top-level limits.h) since the beginning of the project history.
[f]pathconf is entitled to return -1 as the limit for conf names for
which there is no hard limit, with the usual POSIX note that an
indefinite limit does not imply an infinite limit. in principle we
might should report a limit for filesystems that impose one, but such
functionality is not currently present for any of the pathconf limits,
and adding it is beyond the scope of fixing the incorrect limit.
maintainer's note: while musl does not use the linux kernel headers,
it does provide these three sys/* headers which do nothing but include
the corresponding linux/* headers, since the sys/* versions are the
ones documented for application use (and they arguably provide
interfaces that are not linux-specific but common to other unices).
these headers should probably not be provided by libc (rather by a
separate package), but as long as they are, use the bits header
framework as an aid to out-of-tree ports of musl for non-linux systems
that want to implement them in some other way.
maintainer's note: at some point, probably long before linux separated
the uapi headers, it was the case, or at least I believed it was the
case, that linux/types.h was unsafe to include from userspace. thus,
the inclusion guard macro _LINUX_TYPES_H was defined in sys/kd.h to
prevent linux/kd.h from including linux/types.h (which it spuriously
includes but does not use). as far as I can tell, whatever problem
this was meant to solve does not seem to have been present for a long
time, and the hack was not done correctly anyway, so removing it is
the right thing to do.
sys/ptrace.h is target specific, use bits/ptrace.h to add target
specific macro definitions.
these macros are kept in the generic sys/ptrace.h even though some
targets don't support them:
PTRACE_GETREGS
PTRACE_SETREGS
PTRACE_GETFPREGS
PTRACE_SETFPREGS
PTRACE_GETFPXREGS
PTRACE_SETFPXREGS
so no macro definition got removed in this patch on any target. only
s390x has a numerically conflicting macro definition (PTRACE_SINGLEBLOCK).
the PT_ aliases follow glibc headers, otherwise the definitions come
from linux uapi headers except ones that are skipped in glibc and
there is no real kernel support (s390x PTRACE_*_AREA) or need special
type definitions (mips PTRACE_*_WATCH_*) or only relevant for linux
2.4 compatibility (PTRACE_OLDSETOPTIONS).
new in linux v3.1 commit 3544d72a0e10d0aa1c1bd59ed77a53a59cdc12f7
changed in linux v3.4 commit 5cdf389aee90109e2e3d88085dea4dd5508a3be7
A tracer recieves this event in the waitpid status of a PTRACED_SEIZED
process.
including uchar.h in c++ code is only well defined in c++11 onwards
where char16_t and char32_t type definitions must be hidden since they
are keywords. however some c++ code compiled for older c++ standard
include uchar.h too and they need the typedefs, this fix makes such
code work.
maintainer's note: past sentiment was that, despite being imperfect
and unable to force clearing of all possible copies of sensitive data
(e.g. in registers, register spills, signal contexts left on the
stack, etc.) this function would be added if major implementations
agreed on it, which has happened -- several BSDs and glibc all include
it.
mlock2 syscall was added in linux v4.4 and glibc has api for it.
It falls back to mlock in case of flags==0, so that case works
even on older kernels.
MLOCK_ONFAULT is moved under _GNU_SOURCE following glibc.
PR_{SET,GET}_SPECULATION_CTRL controls speculation related vulnerability
mitigations, new in commits
b617cfc858161140d69cc0b5cc211996b557a1c7
356e4bfff2c5489e016fdb925adbf12a1e3950ee
new and missing netlink attributes types for SCM_TIMESTAMPING_OPT_STATS,
new ones were added in commits
7156d194a0772f733865267e7207e0b08f81b02b
be631892948060f44b1ceee3132be1266932071e
87ecc95d81d951b0984f2eb9c5c118cb68d0dce8
introduced to stat ipc objects without permission checks since the
info is available in /proc/sysvipc anyway, new in linux commits
23c8cec8cf679b10997a512abb1e86f0cedc42ba
a280d6dc77eb6002f269d58cd47c7c7e69b617b6
c21a6970ae727839a2f300cd8dd957de0d0238c3
to map at a fixed address without unmapping underlying mappings
(fails with EEXIST unlike MAP_FIXED), new in linux commits
4ed28639519c7bad5f518e70b3284c6e0763e650 and
a4ff8e8620d3f4f50ac4b41e8067b7d395056843.
to get seccomp state for checkpoint restore.
added in linux commit 26500475ac1b499d8636ff281311d633909f5d20
struct tag follows the glibc api and ptrace_peeksiginfo_args
got changed too accordingly.
added to uapi in commit 65aaf87b3aa2d049c6b9fd85221858a895df3393
used since commit a9a08845e9acbd224e4ee466f5c1275ed50054e8,
which renamed POLL* to EPOLL* in the kernel.
commit d93c0740d8 added use of feature
test macros without including features.h, causing a definition that
should be exposed in the default profile, TSVTX, to appear only when
_XOPEN_SOURCE or higher is explicitly defined.
standing alone, both the signed and int keywords identify the same
type, a (signed) int. however the C language has an exception where,
when the lone keyword int is used to declare a bitfield, it's
implementation-defined whether the bitfield is signed or unsigned. C11
footnote 125 extends this implementation-definedness to typedefs, and
DR#315 extends it to other integer types (for which support with
bitfields is implementation-defined).
while reasonable ABIs (all the ones we support) define bitfields as
signed by default, GCC and compatible compilers offer an option
-funsigned-bitfields to change the default. while any signed types
defined without explicit use of the signed keyword are affected, the
stdint.h types, especially intNN_t, have a natural use in bitfields.
ensure that bitfields defined with these types always have the correct
signedness regardless of compiler & flags used.
see also GCC PR 83294.
this must have been taken from POSIX without realizing that it was
meaningless. the resolution to Austin Group issue #844 removed it from
the standard.
PAGESIZE is actually the version defined in POSIX base, with PAGE_SIZE
being in the XSI option. use PAGESIZE as the underlying definition to
facilitate making exposure of PAGE_SIZE conditional.
add a member of appropriate type to the fpos_t union so that accesses
are well-defined. use long long instead of off_t since off_t is not
always exposed in stdio.h and there's no namespace-clean alias for it.
access is still performed using pointer casts rather than by naming
the union member as a matter of style; to the extent possible, the
naming of fields in opaque types defined in the public headers is not
treated as an API contract with the implementation. access via the
pointer cast is valid as long as the union has a member of matching
type.
based loosely on patch by Hauke Mehrtens; converted to wrap the public
API of the underlying getrandom function rather than direct syscalls,
so that if/when a fallback implementation of getrandom is added it
will automatically get picked up by getentropy too.
NT_ARM_SVE and NT_S390_RI_CB are new in linux commits
43d4da2c45b2f5d62f8a79ff7c6f95089bb24656 and
262832bc5acda76fd8f901d39f4da1121d951222
the rest are older.
musl missed NT_PRFPREG because it followed the glibc api:
https://sourceware.org/bugzilla/show_bug.cgi?id=14890
PR_SVE_SET_VL and PR_SVE_GET_VL controls are new in linux commit
2d2123bc7c7f843aa9db87720de159a049839862
related PR_SVE_* macros were added in
7582e22038a266444eb87bc07c372592ad647439
for synchronous page faults, new in linux commit
1c9725974074a047f6080eecc62c50a8e840d050 and
b6fb293f2497a9841d94f6b57bd2bb2cd222da43
note that only targets that use asm-generic/mman.h have this new
flag defined, so undef it on other targets (mips*, powerpc*).
*_HUGE_SHIFT, *_HUGE_2MB, *_HUGE_1GB are documented in the man page,
so add all of the *_HUGE_* macros from linux uapi.
if MAP_HUGETLB is set, top bits of the mmap flags encode the page size.
see the linux commit aafd4562dfee81a40ba21b5ea3cf5e06664bc7f6
if SHM_HUGETLB is set, top bits of the shmget flags encode the page size.
see the linux commit 4da243ac1cf6aeb30b7c555d56208982d66d6d33
*_HUGE_16GB is defined unsigned to avoid signed left shift ub.
new ethertypes in linux v4.14:
ETH_P_ERSPAN new in 84e54fe0a5eaed696dee4019c396f8396f5a908b
ETH_P_IFE new in 2804fd3af6ba5ae5737705b27146455eabe2e2f8
ETH_P_NSH new in 155e6f649757c902901e599c268f8b575ddac1f8
ETH_P_MAP new in 7373ae7e8f0bf2c0718422481da986db5058b005
MSG_ZEROCOPY socket send flag avoids copy in the kernel
new in linux commit 52267790ef52d7513879238ca9fac22c1733e0e3
SO_ZEROCOPY socket option enables MSG_ZEROCOPY if availale
new in linux commit 76851d1212c11365362525e1e2c0a18c97478e6b
add AF_SMC and PF_SMC for the IBM shared memory communication protocol.
new in linux commit ac7138746e14137a451f8539614cdd349153e0c0
(linux socket.h is not in uapi so this update was missed earlier)
With Linux kernel 4.16 it will be possible to guard more parts of the
Linux header files from a libc. Make use of this in musl to guard all
the structures and other definitions from the Linux header files which
are also defined by the header files provided by musl. This will make
it possible to compile source files which include both the libc
headers and the kernel userspace headers.
This extends the definitions done in commit 04983f2272 ("make
netinet/in.h suppress clashing definitions from kernel headers")
notes added by maintainer:
this function is a GNU extension. it was chosen over the similar BSD
function funopen because the latter depends on fpos_t being an
arithmetic type as part of its public API, conflicting with our
definition of fpos_t and with the intent that it be an opaque type. it
was accepted for inclusion because, despite not being widely used, it
is usually very difficult to extricate software using it from the
dependency on it.
calling pattern for the read and write callbacks is not likely to
match glibc or other implementations, but should work with any
reasonable callbacks. in particular the read function is never called
without at least one byte being needed to satisfy its caller, so that
spurious blocking is not introduced.
contracts for what callbacks called from inside libc/stdio can do are
always complicated, and at some point still need to be specified
explicitly. at the very least, the callbacks must return or block
indefinitely (they cannot perform nonlocal exits) and they should not
make calls to stdio using their own FILE as an argument.
for getting/setting write lifetime hints fcntl commands were
added in linux commit c75b1d9421f80f4143e389d2d50ddfc8a28c8c35
added under _GNU_SOURCE || _BSD_SOURCE, since RWH_* life time
hints are not in the POSIX reserved namespace.
SO_MEMINFO added in linux commit a2d133b1d465016d0d97560b11f54ba0ace56d3e
SO_INCOMING_NAPI_ID added in 6d4339028b350efbf87c61e6d9e113e5373545c9
SO_COOKIE added in 5daab9db7b65df87da26fd8cfa695fb9546a1ddb
min max mtu size definitions mostly for drivers.
new in linux commits a52ad514fdf3b8a57ca4322c92d2d8d5c6182485 and
d894be57ca92c8a8819ab544d550809e8731137b
for tcp timestamp control messages, new in linux commit
1c885808e45601b2b6f68b30ac1d999e10b6f606
and export time measurements via tcp_info, added in linux commit
efd90174167530c67a54273fd5d8369c87f9bd32
since setlocale(cat, NULL) is required to return the setting for the
global locale, there is no standard mechanism to obtain the name of
the currently active thread-local locale set by uselocale. this makes
it impossible for application/library software to load appropriate
translations, etc. unless using the gettext implementation provided by
libc, which has privileged access to libc internals.
to fill this gap, glibc introduced the _NL_LOCALE_NAME macro which can
be used with nl_langinfo to obtain the name. GNU gettext/gnulib code
already use this functionality on glibc, and can easily be adapted to
make use of it on non-glibc systems if it's available; for other
systems they poke at locale implementation internals, which we want to
avoid. this patch provides a compatible interface to the one glibc
introduced.
the bit is reserved anyway for ABI-compat reasons; this documents it
and makes it so we can have posix_spawnattr_setflags check for flag
validity without hard-coding an anonymous bit value.
this has been slated for removal for a long time. there is
fundamentally no way to implement stdarg without compiler assistance;
any attempt to do so has serious undefined behavior; its working
depends not just (as a common misconception goes) on ABI, but also on
assumptions about compiler code generation internal to a translation
unit, which is not subject to external ABI constraints.
alpha and s390x gratuitously use 64-bit entries (wasting 2x space and
cache utilization) despite the values always being 32-bit.
based on patch by Bobby Bingham, with changes suggested by Alexander
Monakov to use the public Elf_Symndx type from link.h (and make it
properly variable by arch) rather than adding new internal
infrastructure for handling the type.
based on patch by Timo Teräs:
While generally this is a bad API, it is the only existing API to
affect c++ (std::thread) and c11 (thrd_create) thread stack size.
This patch allows applications only to increate stack and guard
page sizes.
the linux kernel uapi headers provide their own definitions of the
structures from netinet/in.h, resulting in errors when a program
includes both the standard libc header and one or more of the
networking-related kernel headers that pull in the kernel definitions.
as before, we do not attempt to support the case where kernel headers
are included before the libc ones, since the kernel definitions may
have subtly incorrect types, namespace violations, etc. however, we
can easily support the inclusion of the kernel headers after the libc
ones, since the kernel headers provide a public interface for
suppressing their definitions. this patch adds the necessary macro
definitions for such suppression.
the value 19991006 for __RES implies availability of res_ninit and
related functions that take a resolver state argument; these are not
supported since our resolver is stateless. instead claim support for
just the older API by defining __RES to 19960801.
based on patch by Dmitrij D. Czarkoff.
ETH_P_HSR (IEC 62439-3 HSRv1) added in
linux 4.7 commit ee1c27977284907d40f7f72c2d078d709f15811f
ETH_P_TSN (IEEE 1722) added in
linux 4.3 commit 1ab1e895492d8084dfc1c854efacde219e56b8c1
this constant breaks the ascending order to match the kernel header
ETH_P_XDSA (Multiplexed DSA protocol) added in
linux 3.18 commit 3e8a72d1dae374cf6fc1dba97cec663585845ff9
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.
some software simply uses static_assert if the macro is defined, and
this breaks if the compiler does not recognize the _Static_assert
keyword used to define it.
commit 378f8cb522 added these functions
(as stubs) but left them without declarations. this broke some
autoconf based software that detected linkability of the symbols but
didn't check for a declaration.
si_errno and si_code are swapped in mips siginfo_t compared to other
archs and some si_code values are different. This fix is required
for POSIX timers to work.
based on patch by Dmitry Ivanov.
only have code above the bits/signal.h include that is necessary.
(some types are used for the ucontext struct and mips has to
override a few macro definitions)
this way mips bits/signal.h will be able to affect siginfo_t.
they lock faulted pages into memory (useful when a small part of a
large mapped file needs efficient access), new in linux v4.4, commit
b0f205c2a3082dd9081f9a94e50658c5fa906ff1
MLOCK_* is not in the POSIX reserved namespace for sys/mman.h
allows a ptracer process to disable/enable seccomp filters of the
traced process, useful for checkpoint/restore, new in v4.3 commit
13c4a90119d28cfcb6b5bdd820c233b86c2b0237
IP_BIND_ADDRESS_NO_PORT is a SOL_IP socket option to delay src port
allocation until connect in case src ip is set with bind(port=0).
new in linux v4.2, commit 90c337da1524863838658078ec34241f45d8394d
IPPROTO_MPLS protocol number for mpls over ip.
new in linux v4.2, commit 730fc4371333636a00fed32c587fc1e85c5367e2
TCP_CC_INFO is a new socket option to get congestion control info without
netlink (union tcp_cc_info is in linux/inet_diag.h kernel header).
linux commit 6e9250f59ef9efb932c84850cd221f22c2a03c4a
TCP_SAVE_SYN, TCP_SAVED_SYN socket options are for saving and getting the
SYN headers of passive connections in a server application.
linux commit cd8ae85299d54155702a56811b2e035e63064d3d
Add new tcpi_* fields to struct tcp_info implementing RFC4898 counters.
linux commit 2efd055c53c06b7e89c167c98069bab9afce7e59
Programs such as iptables depend on these constants, which can also
be found defined in other libcs.
Since only TCP_* is reserved as part of tcp.h's namespace, we hide
them behind _BSD_SOURCE (and therefore _DEFAULT_SOURCE) to expose
them by default, but keep it standard conforming.
this attribute was applied to pthread_self and the functions providing
the locations for errno and h_errno as an optimization; however, it is
subtly incorrect. as specified, it means the return value will always
be the same, which is not true; it varies per-thread.
this attribute also implies that the function does not depend on any
state, and that calls to it can safely be reordered across any other
code. however such reordering is unsafe for these functions: they
break when reordered before initialization of the thread pointer. such
breakage was actually observed when compiled by libfirm/cparser.
to some extent the reordering problem could be solved with strong
compiler barriers between the stages of early startup code, but the
specified meaning of of attribute((const)) is sufficiently strong that
a compiler would theoretically be justified inserting gratuitous calls
to attribute((const)) const functions at random locations (e.g. to
save the value in static storage for later use).
this reverts commit cbf35978a9.
their absence completely breaks format string warnings in programs
with gettext message translations: -Wformat gives no results, and
-Wformat-nonliteral produces spurious warnings.
with gcc, the problem manifests only in standards-conforming profiles;
otherwise gcc sets these attributes by default for the gettext family.
with clang, the problem always manifests; clang has no such defaults.
being nonstandard, the closest thing to a specification for this
function is its man page, which documents it as returning int. it can
fail with EBADF if the file descriptor passed is invalid.
this patch activates the new byte-based C locale (high bytes treated
as abstract code unit "characters" rather than decoded as multibyte
characters) by making the value of MB_CUR_MAX depend on the active
locale. for the C locale, the LC_CTYPE category pointer is null,
yielding a value of 1. all other locales yield a value of 4.
the casts of the argument to unsigned int suppressed diagnosis of
errors like passing a pointer instead of a character. putting the
actual function call in an unreachable branch restores any diagnostics
that would be present if the macros didn't exist and functions were
used.
the C standard specifies that setjmp is a macro, but longjmp is a
normal function. a macro version of it would be permitted (albeit
useless) for C (not C++), but would have to be a function-like macro,
not an object-like one.
while it's the same for all presently supported archs, it differs at
least on sparc, and conceptually it's no less arch-specific than the
other O_* macros. O_SEARCH and O_EXEC are still defined in terms of
O_PATH in the main fcntl.h.
commit 559de8f5f0 redefined FLT_ROUNDS
to use an external function that can report the actual current
rounding mode, rather than always reporting round-to-nearest. however,
float.h did not include 'extern "C"' wrapping for C++, so C++ programs
using FLT_ROUNDS ended up with an unresolved reference to a
name-mangled C++ function __flt_rounds.
the previous values (2k min and 8k default) were too small for some
archs. aarch64 reserves 4k in the signal context for future extensions
and requires about 4.5k total, and powerpc reportedly uses over 2k.
the new minimums are chosen to fit the saved context and also allow a
minimal signal handler to run.
since the default (SIGSTKSZ) has always been 6k larger than the
minimum, it is also increased to maintain the 6k usable by the signal
handler. this happens to be able to store one pathname buffer and
should be sufficient for calling any function in libc that doesn't
involve conversion between floating point and decimal representations.
x86 (both 32-bit and 64-bit variants) may also need a larger minimum
(around 2.5k) in the future to support avx-512, but the values on
these archs are left alone for now pending further analysis.
the value for PTHREAD_STACK_MIN is not increased to match MINSIGSTKSZ
at this time. this is so as not to preclude applications from using
extremely small thread stacks when they know they will not be handling
signals. unfortunately cancellation and multi-threaded set*id() use
signals as an implementation detail and therefore require a stack
large enough for a signal context, so applications which use extremely
small thread stacks may still need to avoid using these features.
