to request or change pointer auth keys for criu via ptrace, new in
linux commit d0a060be573bfbf8753a15dca35497db5e968bb0
arm64: add ptrace regsets for ptrauth key management
RFC 4286: "The IPv4 multicast address for All-Snoopers is 224.0.0.106."
from
linux commit 4effd28c1245303dce7fd290c501ac2c11052114
bridge: join all-snoopers multicast address
SO_BINDTOIFINDEX behaves similar to SO_BINDTODEVICE, but takes a
network interface index as argument, rather than the network
interface name. see
linux commit f5dd3d0c9638a9d9a02b5964c4ad636f06cf7e2c
net: introduce SO_BINDTOIFINDEX sockopt
restricts router alert packets received by the socket to the
socket's namespace only. see
linux commit 9036b2fe092a107856edd1a3bad48b83f2b45000
net: ipv6: add socket option IPV6_ROUTER_ALERT_ISOLATE
allows specifying that the speculative store bypass disable bit should
be cleared on exec. see
linux commit 71368af9027f18fe5d1c6f372cfdff7e4bde8b48
x86/speculation: Add PR_SPEC_DISABLE_NOEXEC
needed for android so it can migrate from its ashmem to memfd.
allows making the memfd readonly for future users while keeping
a writable mmap of it. see
linux commit ab3948f58ff841e51feb845720624665ef5b7ef3
mm/memfd: add an F_SEAL_FUTURE_WRITE seal to memfd
includes changes from linux v5.1
linux commit 235328d1fa4251c6dcb32351219bb553a58838d2
fanotify: add support for create/attrib/move/delete events
linux commit 5e469c830fdb5a1ebaa69b375b87f583326fd296
fanotify: copy event fid info to user
linux commit e9e0c8903009477b630e37a8b6364b26a00720da
fanotify: encode file identifier for FAN_REPORT_FID
as well as earlier changes that were missed.
sys/statfs.h is included for fsid_t.
this reverts commit f552c792c7, which
exposed the sysmacros.h macros (device major/minor calculations) for
BSD and GNU profiles to mimic an unintentional glibc behavior some
code depended on. glibc has deprecated and since removed them as the
resolution to bug #19239, so it makes no sense for us to keep this
behavior. affected code should all have been fixed by now, and if it's
not yet fixed it needs to be for use with modern glibc anyway.
Author: Alex Suykov <alex.suykov@gmail.com>
Author: Aric Belsito <lluixhi@gmail.com>
Author: Drew DeVault <sir@cmpwn.com>
Author: Michael Clark <mjc@sifive.com>
Author: Michael Forney <mforney@mforney.org>
Author: Stefan O'Rear <sorear2@gmail.com>
This port has involved the work of many people over several years. I
have tried to ensure that everyone with substantial contributions has
been credited above; if any omissions are found they will be noted
later in an update to the authors/contributors list in the COPYRIGHT
file.
The version committed here comes from the riscv/riscv-musl repo's
commit 3fe7e2c75df78eef42dcdc352a55757729f451e2, with minor changes by
me for issues found during final review:
- a_ll/a_sc atomics are removed (according to the ISA spec, lr/sc
are not safe to use in separate inline asm fragments)
- a_cas[_p] is fixed to be a memory barrier
- the call from the _start assembly into the C part of crt1/ldso is
changed to allow for the possibility that the linker does not place
them nearby each other.
- DTP_OFFSET is defined correctly so that local-dynamic TLS works
- reloc.h LDSO_ARCH logic is simplified and made explicit.
- unused, non-functional crti/n asm files are removed.
- an empty .sdata section is added to crt1 so that the
__global_pointer reference is resolvable.
- indentation style errors in some asm files are fixed.
FP_FAST_FMA can be defined if "the fma function generally executes about
as fast as, or faster than, a multiply and an add of double operands",
which can only be true if the fma call is inlined as an instruction.
gcc sets __FP_FAST_FMA if __builtin_fma is inlined as an instruction,
but that does not mean an fma call will be inlined (e.g. it is defined
with -fno-builtin-fma), other compilers (clang) don't even have such
macro, but this is the closest we can get.
(even if the libc fma implementation is a single instruction, the extern
call overhead is already too big when the macro is used to decide between
x*y+z and fma(x,y,z) so it cannot be based on libc only, defining the
macro unconditionally on targets which have fma in the base isa is also
incorrect: the compiler might not inline fma anyway.)
this solution works with gcc unless fma inlining is explicitly turned off.
POSIX: "[If] either O_TTY_INIT is set in oflag or O_TTY_INIT has the
value zero, open() shall set any non-standard termios structure
terminal parameters to a state that provides conforming behavior."
The Linux kernel tty drivers always perform initialisation on their
devices to set known good termios values during the open(2) call. This
means that setting O_TTY_INIT to zero is conforming.
This parameter was incorrectly declared to be a pointer to a function
accepting zero parameters. The intent of makecontext is that it is
possible to pass integer parameters to the function, so this should
have been a pointer to a function accepting an unspecified set of
parameters.
aarch64 pointer authentication code related prctl that allows
reinitializing the key for the thread, added in linux commit
ba830885656414101b2f8ca88786524d4bb5e8c1
NT_MIPS_MSA for ptrace access to mips simd arch reg set, added in linux
commit 3cd640832894b85b5929d5bda74505452c800421
NT_ARM_PAC_MASK for ptrace access to pointer auth code mask, added in
commit ec6e822d1a22d0eef1d1fa260dff751dba9a4258
C-SKY support was added to binutils 2.32 in commit
b8891f8d622a31306062065813fc278d8a94fe21
the elf.h change was added to glibc 2.29 in commit
4975f0c3d0131fdf697be0b1631c265e5fd39088
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.
