Szabolcs Nagy [Sat, 19 Dec 2020 22:29:19 +0000 (22:29 +0000)]
aarch64/bits/mman.h: add PROT_MTE from linux v5.10
see
linux commit
9f3419315f3cdc41a7318e4d50ba18a592b30c8c
arm64: mte: Add PROT_MTE support to mmap() and mprotect()
Szabolcs Nagy [Sat, 19 Dec 2020 22:26:51 +0000 (22:26 +0000)]
aarch64/bits/hwcap.h: add HWCAP2_MTE from linux v5.10
see
linux commit
3b714d24ef173f81c78af16f73dcc9b40428c803
arm64: mte: CPU feature detection and initial sysreg configuration
Szabolcs Nagy [Sat, 19 Dec 2020 22:25:03 +0000 (22:25 +0000)]
add aarch64/bits/mman.h with PROT_BTI from linux v5.8
this was missing, see
linux commit
8ef8f360cf30be12382f89ff48a57fbbd9b31c14
arm64: Basic Branch Target Identification support
Szabolcs Nagy [Sat, 19 Dec 2020 22:22:58 +0000 (22:22 +0000)]
aarch64/bits/hwcap.h: add HWCAP2_BTI from linux v5.8
hwcap for BTI was missing, see
linux commit
8ef8f360cf30be12382f89ff48a57fbbd9b31c14
arm64: Basic Branch Target Identification support
Szabolcs Nagy [Sat, 19 Dec 2020 22:12:50 +0000 (22:12 +0000)]
signal.h: add MTE specific SIGSEGV codes from linux v5.10
add synchronouse and asynchronous tag check failure codes, see
linux commit
74f1082487feb90bbf880af14beb8e29c3030c9f
arm64: mte: Add specific SIGSEGV codes
Szabolcs Nagy [Sat, 19 Dec 2020 21:10:26 +0000 (21:10 +0000)]
sys/prctl.h: add MTE related constants from linux v5.10
these are for the aarch64 MTE (memory tagging extension), see
linux commit
1c101da8b971a36695319dce7a24711dc567a0dd
arm64: mte: Allow user control of the tag check mode via prctl()
linux commit
af5ce95282dc99d08a27a407a02c763dde1c5558
arm64: mte: Allow user control of the generated random tags via prctl()
Szabolcs Nagy [Sat, 19 Dec 2020 21:06:06 +0000 (21:06 +0000)]
elf.h: add NT_ARM_TAGGED_ADDR_CTRL from linux v5.10
see
linux commit
2200aa7154cb7ef76bac93e98326883ba64bfa2e
arm64: mte: ptrace: Add NT_ARM_TAGGED_ADDR_CTRL regset
Szabolcs Nagy [Sat, 19 Dec 2020 21:02:21 +0000 (21:02 +0000)]
sys/mman.h: add MAP_HUGE_16KB from linux v5.10
see
linux commit
e47168f3d1b14af5281cf50c59561d59d28201f9
powerpc/8xx: Support 16k hugepages with 4k pages
Szabolcs Nagy [Sat, 19 Dec 2020 20:56:23 +0000 (20:56 +0000)]
sys/mount.h: add MS_NOSYMFOLLOW from linux v5.10
path resolution does not follow symlinks on nosymfollow mounts (but
readlink still does), see
linux commit
dab741e0e02bd3c4f5e2e97be74b39df2523fc6e
Add a "nosymfollow" mount option.
Szabolcs Nagy [Sat, 19 Dec 2020 20:27:22 +0000 (20:27 +0000)]
sys/membarrier.h: add new constants from linux v5.10
can cause rseq restart on another cpu to synchronize with global
memory access from rseq critical sections, see
linux commit
2a36ab717e8fe678d98f81c14a0b124712719840
rseq/membarrier: Add MEMBARRIER_CMD_PRIVATE_EXPEDITED_RSEQ
Szabolcs Nagy [Sat, 19 Dec 2020 20:12:31 +0000 (20:12 +0000)]
bits/syscall.h: add process_madvise from linux v5.10
mainly added to linux to allow a central process management service in
android to give MADV_COLD|PAGEOUT hints for other processes, see
linux commit
ecb8ac8b1f146915aa6b96449b66dd48984caacc
mm/madvise: introduce process_madvise() syscall: an external memory
hinting API
Rich Felker [Sat, 13 Feb 2021 19:03:23 +0000 (14:03 -0500)]
fix error return value for cuserid
the historical function was specified to return an empty string in the
caller-provided buffer, not a null pointer, to indicate error when the
argument is non-null. only when the argument is null should it return
a null pointer on error.
Rich Felker [Sat, 13 Feb 2021 18:59:44 +0000 (13:59 -0500)]
fix misuse of getpwuid_r in cuserid
getpwuid_r can return 0 but without a result in the case where there
was no error but no record exists. in that case cuserid was treating
it as success and copying junk out of pw.pw_name to the output buffer.
Rich Felker [Sat, 13 Feb 2021 18:54:00 +0000 (13:54 -0500)]
cuserid: don't return truncated results
checking the length also drops the need to pull in snprintf.
Sören Tempel [Wed, 29 Jan 2020 11:20:07 +0000 (12:20 +0100)]
cuserid: support invocation with a null pointer argument
this function was removed from the standard in 2001 but appeared in
SUSv2 with an obligation to support calls with a null pointer
argument, using a static buffer.
Khem Raj [Mon, 11 Jan 2021 17:40:33 +0000 (09:40 -0800)]
riscv64: define ELF_NFPREG
ELF_NFPREG is used by some userspace applications like gdb
Szabolcs Nagy [Fri, 5 Feb 2021 19:51:36 +0000 (19:51 +0000)]
math: fix expm1f overflow threshold
the threshold was wrong so expm1f overflowed to inf a bit too early
and on most targets uint32_t compare is faster than float compare so
use that.
this also fixes sinhf incorrectly returning nan for some values where
the internal expm1f overflowed.
Szabolcs Nagy [Fri, 5 Feb 2021 18:48:19 +0000 (18:48 +0000)]
math: fix acoshf for negative inputs
on some negative inputs (e.g. -0x1.1e6ae8p+5) acoshf failed to return
nan. ensure that negative inputs result nan without introducing new
branches. this was tried before in
commit
101e6012856918440b5d7474739c3fc22a8d3b85
math: fix acoshf on negative values
but that fix was wrong. there are 3 formulas used:
log1p(x-1 + sqrt((x-1)*(x-1)+2*(x-1)))
log(2*x - 1/(x+sqrt(x*x-1)))
log(x) + 0.
693147180559945309417232121458176568
the first fails on large negative inputs (may compute log1p(0) or
log1p(inf)), the second one fails on some mid range or large negative
inputs (may compute log(large) or log(inf)) and the last one fails on
-0 (returns -inf).
Érico Rolim [Thu, 24 Dec 2020 04:18:04 +0000 (01:18 -0300)]
fix possible fd leak via missing O_CLOEXEC in pthread_setname_np
the omission of the flag here seems to have been an oversight when the
function was added in
8fb28b0b3e7a5e958fb844722a4b2ef9bc244af1
Rich Felker [Sat, 30 Jan 2021 22:28:08 +0000 (17:28 -0500)]
oldmalloc: preserve errno across free
as an outcome of Austin Group issue #385, future versions of the
standard will require free not to alter the value of errno. save and
restore it individually around the calls to madvise and munmap so that
the cost is not imposed on calls to free that do not result in any
syscall.
Rich Felker [Sat, 30 Jan 2021 22:26:34 +0000 (17:26 -0500)]
fix build regression in oldmalloc
commit
8d37958d58cf36f53d5fcc7a8aa6d633da6071b2 inadvertently broke
oldmalloc by having it implement __libc_malloc rather than
__libc_malloc_impl.
Rich Felker [Sat, 30 Jan 2021 22:14:20 +0000 (17:14 -0500)]
preserve errno across free
as an outcome of Austin Group issue #385, future versions of the
standard will require free not to alter the value of errno. save and
restore it individually around the calls to madvise and munmap so that
the cost is not imposed on calls to free that do not result in any
syscall.
Rich Felker [Sat, 30 Jan 2021 21:42:26 +0000 (16:42 -0500)]
fix inconsistent signature of __libc_start_main
commit
7586360badcae6e73f04eb1b8189ce630281c4b2 removed the unused
arguments from the definition of __libc_start_main, making it
incompatible with the declaration at the point of call, which still
passed 6 arguments. calls with mismatched function type have undefined
behavior, breaking LTO and any other tooling that checks for function
signature mismatch.
removing the extra arguments from the point of call (crt1) is not an
option for fixing this, since that would be a change in ABI surface
between application and libc.
adding back the extra arguments requires some care. on archs that pass
arguments on the stack or that reserve argument spill space for the
callee on the stack, it imposes an ABI requirement on the caller to
provide such space. the modern crt1.c entry point provides such space,
but originally there was arch-specific asm for the call to
__libc_start_main. the last of this asm was removed in commit
6fef8cafbd0f6f185897bc87feb1ff66e2e204e1, and manual review of the
code removed and its prior history was performed to check that all
archs/variants passed the legacy init/fini/ldso_fini arguments.
Rich Felker [Sat, 30 Jan 2021 21:09:22 +0000 (16:09 -0500)]
fail posix_spawn file_actions operations with negative fds
these functions are specified to fail with EBADF on negative fd
arguments. apart from close, they are also specified to fail if the
value exceeds OPEN_MAX, but as written it is not clear that this
imposes any requirement when OPEN_MAX is not defined, and it's
undesirable to impose a dynamic limit (via setrlimit) here since the
limit at the time of posix_spawn may be different from the limit at
the time of setting up the file actions. this may require revisiting
later.
Rich Felker [Fri, 15 Jan 2021 02:26:00 +0000 (21:26 -0500)]
release 1.2.2
Rich Felker [Mon, 14 Dec 2020 16:10:30 +0000 (11:10 -0500)]
fix VIDIOC_DQEVENT (v4l2) ioctl fallback for pre-5.6 kernels
commit
2412638bb39eb799b2600393bbd71cca8ae96bb2 got the size of struct
v4l2_event wrong and failed to account for the fact that the old
struct might be either 120 bytes with time misaligned mod 8, or 128
bytes with time aligned mod 8, due to the contained union having
64-bit members whose alignment is arch-dependent.
rather than adding new logic to handle the differences, use an actual
stripped-down version of the structure in question to derive the ioctl
number, size, and offsets.
Arnd Bergmann [Mon, 14 Dec 2020 02:43:16 +0000 (21:43 -0500)]
fix v4l2 buffer ioctl fallbacks for pre-5.6 kernels
commit
2412638bb39eb799b2600393bbd71cca8ae96bb2 got the size of struct
v4l2_buffer wrong and omitted the tv_usec member slot from the offset
list, so the ioctl numbers never matched and fallback code path was
never taken. this caused the affected ioctls to fail with ENOTTY on
kernels not new enough to have the native time64 ioctls.
Ariadne Conill [Sat, 12 Dec 2020 04:30:53 +0000 (04:30 +0000)]
sh: fix incorrect mcontext_t member naming
while the layouts match, the member member naming expected by software
using mcontext_t omits the sc_ prefix.
Rich Felker [Wed, 9 Dec 2020 22:11:05 +0000 (17:11 -0500)]
use libc-internal malloc for newlocale/freelocale
this is necessary for MT-fork correctness now that the code runs under
locale lock. it would not be hard to avoid, but __get_locale is
already using libc-internal malloc anyway. this can be reconsidered
during locale overhaul later if needed.
Rich Felker [Wed, 9 Dec 2020 22:01:57 +0000 (17:01 -0500)]
drop use of pthread_once in newlocale
in general, pthread_once is not compatible with MT-fork constraints
(commit
167390f05564e0a4d3fcb4329377fd7743267560). here it actually no
longer matters, because it's now called with a lock held, but since
the lock is held it's pointless to use pthread_once.
Rich Felker [Wed, 9 Dec 2020 21:58:32 +0000 (16:58 -0500)]
lift locale lock out of internal __get_locale
this allows the lock to be shared with setlocale, eliminates repeated
per-category lock/unlock in newlocale, and will allow the use of
pthread_once in newlocale to be dropped (to be done separately).
Rich Felker [Wed, 9 Dec 2020 16:34:29 +0000 (11:34 -0500)]
fix misleading comment in strstr
the intent here is just to scan at least l bytes forward for the end
of the haystack and at least some decent minimum to avoid doing it
over and over if the needle is short, with no need to be precise. the
comment erroneously stated this as an estimate for MIN when it's
actually an estimate for MAX.
Rich Felker [Tue, 8 Dec 2020 23:02:39 +0000 (18:02 -0500)]
drop use of pthread_once for aio thread stack size init
pthread_once is not compatible with MT-fork constraints (commit
167390f05564e0a4d3fcb4329377fd7743267560) and is not needed here
anyway; we already have a lock suitable for initialization.
while changing this, fix a corner case where AT_MINSIGSTKSZ gives a
value that's more than MINSIGSTKSZ but by a margin of less than
2048, thereby causing the size to be reduced. it shouldn't matter but
the intent was to be the larger of a 2048-byte margin over the legacy
fixed minimum stack requirement or a 512-byte margin over the minimum
the kernel reports at runtime.
Rich Felker [Mon, 7 Dec 2020 22:25:08 +0000 (17:25 -0500)]
fix omission of non-stub pthread_mutexattr_getprotocol
this change should have been made when priority inheritance mutex
support was added. if priority protection is also added at some point
the implementation will need to change and will probably no longer be
a simple bit shuffling.
Drew DeVault [Sat, 5 Dec 2020 18:10:06 +0000 (18:10 +0000)]
riscv64: fix inconsistent ucontext_t struct tag
ucontext.h depends on the internal struct tag name for namespacing
reasons, and the intent was always for it to be consistent across
archs anyway.
Rich Felker [Fri, 4 Dec 2020 22:01:05 +0000 (17:01 -0500)]
fix failure to preserve r6 in s390x asm; per ABI it is call-saved
both __clone and __syscall_cp_asm failed to restore the original value
of r6 after using it as a syscall argument register. the extent of
breakage is not known, and in some cases may be mitigated by the only
callers being internal to libc; if they used r6 but no longer needed
its value after the call, they may not have noticed the problem.
however at least posix_spawn (which uses __clone) was observed
returning to the application with the wrong value in r6, leading to
crash.
since the call frame ABI already provides a place to spill registers,
fixing this is just a matter of using it. in __clone, we also
spuriously restore r6 in the child, since the parent branch directly
returns to the caller. this takes the value from an uninitialized slot
of the child's stack, but is harmless since there is no caller to
return to in the child.
Marius Hillenbrand [Tue, 1 Dec 2020 14:36:34 +0000 (15:36 +0100)]
s390x: derive float_t from compiler or default to float
float_t should represent the type that is used to evaluate float
expressions internally. On s390x, float_t is currently set to double.
In contrast, the isa supports single-precision float operations and
compilers by default evaluate float in single precision, which
violates the C standard (sections 5.2.4.2.2 and 7.12 in C11/C17, to be
precise). With -fexcess-precision=standard, gcc evaluates float in
double precision, which aligns with the standard yet at the cost of
added conversion instructions.
gcc-11 will drop the special case to retrofit double precision
behavior for -fexcess-precision=standard so that __FLT_EVAL_METHOD__
will be 0 on s390x in any scenario.
To improve standards compliance and compatibility with future compiler
direction, this patch changes the definition of float_t to be derived
from the compiler's __FLT_EVAL_METHOD__.
Ariadne Conill [Sat, 1 Aug 2020 14:26:35 +0000 (08:26 -0600)]
implement reallocarray
reallocarray is an extension introduced by OpenBSD, which introduces
calloc overflow checking to realloc.
glibc 2.28 introduced support for this function behind _GNU_SOURCE,
while glibc 2.29 allows its usage in _DEFAULT_SOURCE.
Rich Felker [Mon, 30 Nov 2020 17:14:47 +0000 (12:14 -0500)]
implement realpath directly instead of using procfs readlink
inability to use realpath in chroot/container without procfs access
and at early boot prior to mount of /proc has been an ongoing issue,
and it turns out realpath was one of the last remaining interfaces
that needed procfs for its core functionality. during investigation
while reimplementing, it was determined that there were also serious
problems with the procfs-based implementation. most seriously it was
unsafe on pre-O_PATH kernels, and unlike other places where O_PATH was
used, the unsafety was hard or impossible to fix because O_NOFOLLOW
can't be used (since the whole purpose was to follow symlinks).
the new implementation is a direct one, performing readlink on each
path component to resolve it. an explicit stack, as opposed to
recursion, is used to represent the remaining components to be
processed. the stack starts out holding just the input string, and
reading a link pushes the link contents onto the stack.
unlike many other implementations, this one does not call getcwd
initially for relative pathnames. instead it accumulates initial ..
components to be applied to the working directory if the result is
still a relative path. this avoids calling getcwd (which may fail) at
all when symlink traversal will eventually yield an absolute path. it
also doesn't use any form of stat operation; instead it arranges for
readlink to tell it when a non-directory is used in a context where a
directory is needed. this minimizes the number of syscalls needed,
avoids accessing inodes when the directory table suffices, and reduces
the amount of code pulled in for static linking.
Dominic Chen [Wed, 25 Nov 2020 07:53:16 +0000 (02:53 -0500)]
fix mallocng regression in malloc_usable_size with null argument
commit
d1507646975cbf6c3e511ba07b193f27f032d108 added support for null
argument in oldmalloc and was overlooked when switching to mallocng.
Issam E. Maghni [Mon, 2 Nov 2020 22:16:41 +0000 (17:16 -0500)]
configure: do not use obsolescent form of test -a|o
The -a and -o operators are obsolescent and not in baseline POSIX.
Érico Rolim [Thu, 12 Nov 2020 20:52:23 +0000 (17:52 -0300)]
fix segfault in lutimes when tv argument is NULL
calling lutimes with tv=0 is valid if the application wants to set the
timestamps to the current time. this commit makes it so the timespec
struct is populated with values from tv only if tv != 0 and calls
utimensat with times=0 if tv == 0.
Szabolcs Nagy [Sun, 25 Oct 2020 16:42:41 +0000 (16:42 +0000)]
netinet/in.h: add IP_RECVERR_4884 from linux v5.9
see
linux commit
eba75c587e811d3249c8bd50d22bb2266ccd3c0f
icmp: support rfc 4884
Szabolcs Nagy [Sun, 25 Oct 2020 16:25:34 +0000 (16:25 +0000)]
sys/fanotify.h: add new FAN_* macros from linux v5.9
Update fanotify.h, see
linux commit
929943b38daf817f2e6d303ea04401651fc3bc05
fanotify: add support for FAN_REPORT_NAME
linux commit
83b7a59896dd24015a34b7f00027f0ff3747972f
fanotify: add basic support for FAN_REPORT_DIR_FID
linux commit
08b95c338e0c5a96e47f4ca314ea1e7580ecb5d7
fanotify: remove event FAN_DIR_MODIFY
FAN_DIR_MODIFY that was new in v5.7 is now removed from linux uapi,
but kept in musl, so we don't break api, linux cannot reuse the
value anyway.
Szabolcs Nagy [Sat, 24 Oct 2020 10:15:43 +0000 (10:15 +0000)]
bits/syscall.h: add __NR_close_range from linux v5.9
see
linux commit
9b4feb630e8e9801603f3cab3a36369e3c1cf88d
arch: wire-up close_range()
linux commit
278a5fbaed89dacd04e9d052f4594ffd0e0585de
open: add close_range()
William Woodruff [Wed, 18 Nov 2020 15:59:31 +0000 (10:59 -0500)]
add missing personality values
Adds two missing personality(2) personas: UNAME26 and FDPIC_FUNCPTRS.
FDPIC_FUNCPTRS was also missing its corresponding PER_LINUX_FDPIC
value.
Jinliang Li [Fri, 20 Nov 2020 10:45:03 +0000 (18:45 +0800)]
arm fabs and sqrt: support single-precision-only fpu variants
Érico Rolim [Thu, 26 Nov 2020 13:46:03 +0000 (10:46 -0300)]
fix typo in INSTALL
"big-engian" should be "big-endian".
Rich Felker [Tue, 24 Nov 2020 00:44:19 +0000 (19:44 -0500)]
work around linux bug in readlink syscall with zero buffer size
linux fails with EINVAL when a zero buffer size is passed to the
syscall. this is non-conforming because POSIX already defines EINVAL
with a significantly different meaning: the target is not a symlink.
since the request is semantically valid, patch it up by using a dummy
buffer of length one, and truncating the return value to zero if it
succeeds.
Rich Felker [Sun, 22 Nov 2020 22:26:36 +0000 (17:26 -0500)]
parse v3 or future-unknown zoneinfo file versions as v2+
the v1 zoneinfo format with 32-bit time is deprecated. previously, the
v2 parsing code was only used if an exact match for '2' was found in
the version field of the header. this was already incorrect for v3
files (trivial differences from v2 that arguably didn't merit a new
version number anyway) but also failed to be future-proof.
Rich Felker [Sun, 22 Nov 2020 22:00:01 +0000 (17:00 -0500)]
explicitly prefer 64-bit/v2 zoneinfo tables
since commit
38143339646a4ccce8afe298c34467767c899f51, the condition
sizeof(time_t) > 4 is always true, so there is no functional change
being made here. but semantically, the 64-bit tables should always be
preferred now, because upstream zic (zoneinfo compiler) has quietly
switched to emitting empty 32-bit tables by default, and the resulting
backwards-incompatible zoneinfo files will be encountered in the wild.
Rich Felker [Fri, 20 Nov 2020 15:43:20 +0000 (10:43 -0500)]
fix regression in pthread_exit
commit
d26e0774a59bb7245b205bc8e7d8b35cc2037095 moved the detach state
transition at exit before the thread list lock was taken. this
inadvertently allowed pthread_join to race to take the thread list
lock first, and proceed with unmapping of the exiting thread's memory.
we could fix this by just revering the offending commit and instead
performing __vm_wait unconditionally before taking the thread list
lock, but that may be costly. instead, bring back the old DT_EXITING
vs DT_EXITED state distinction that was removed in commit
8f11e6127fe93093f81a52b15bb1537edc3fc8af, and don't transition to
DT_EXITED (a value of 0, which is what pthread_join waits for) until
after the lock has been taken.
Rich Felker [Thu, 19 Nov 2020 22:12:43 +0000 (17:12 -0500)]
rewrite wcsnrtombs to fix buffer overflow and other bugs
the original wcsnrtombs implementation, which has been largely
untouched since 0.5.0, attempted to build input-length-limiting
conversion on top of wcsrtombs, which only limits output length. as
best I recall, this choice was made out of a mix of disdain over
having yet another variant function to implement (added in POSIX 2008;
not standard C) and preference not to switch things around and
implement the wcsrtombs in terms of the more general new function,
probably over namespace issues. the strategy employed was to impose
output limits that would ensure the input limit wasn't exceeded, then
finish up the tail character-at-a-time. unfortunately, none of that
worked correctly.
first, the logic in the wcsrtombs loop was wrong in that it could
easily get stuck making no forward progress, by imposing an output
limit too small to convert even one character.
the character-at-a-time loop that followed was even worse. it made no
effort to ensure that the converted multibyte character would fit in
the remaining output space, only that there was a nonzero amount of
output space remaining. it also employed an incorrect interpretation
of wcrtomb's interface contract for converting the null character,
thereby failing to act on end of input, and remaining space accounting
was subject to unsigned wrap-around. together these errors allow
unbounded overflow of the destination buffer, controlled by input
length limit and input wchar_t string contents.
given the extent to which this function was broken, it's plausible
that most applications that would have been rendered exploitable were
sufficiently broken not to be usable in the first place. however, it's
also plausible that common (especially ASCII-only) inputs succeeded in
the wcsrtombs loop, which mostly worked, while leaving the wildly
erroneous code in the second loop exposed to particular non-ASCII
inputs.
CVE-2020-28928 has been assigned for this issue.
Rich Felker [Thu, 19 Nov 2020 21:20:45 +0000 (16:20 -0500)]
protect destruction of process-shared mutexes against robust list races
after a non-normal-type process-shared mutex is unlocked, it's
immediately available to another thread to lock, unlock, and destroy,
but the first unlocking thread may still have a pointer to it in its
robust_list pending slot. this means, on async process termination,
the kernel may attempt to access and modify the memory that used to
contain the mutex -- memory that may have been reused for some other
purpose after the mutex was destroyed.
setting up for this kind of race to occur is difficult to begin with,
requiring dynamic use of shared memory maps, and actually hitting the
race is very difficult even with a suitable setup. so this is mostly a
theoretical fix, but in any case the cost is very low.
Rich Felker [Thu, 19 Nov 2020 21:09:16 +0000 (16:09 -0500)]
pthread_exit: don't __vm_wait under thread list lock
the __vm_wait operation can delay forward progress arbitrarily long if
a thread holding the lock is interrupted by a signal. in a worst case
this can deadlock. any critical section holding the thread list lock
must respect lock ordering contracts and must not take any lock which
is not AS-safe.
to fix, move the determination of thread joinable/detached state to
take place before the killlock and thread list lock are taken. this
requires reverting the atomic state transition if we determine that
the exiting thread is the last thread and must call exit, but that's
easy to do since it's a single-threaded context with application
signals blocked.
Rich Felker [Wed, 11 Nov 2020 18:37:33 +0000 (13:37 -0500)]
lift child restrictions after multi-threaded fork
as the outcome of Austin Group tracker issue #62, future editions of
POSIX have dropped the requirement that fork be AS-safe. this allows
but does not require implementations to synchronize fork with internal
locks and give forked children of multithreaded parents a partly or
fully unrestricted execution environment where they can continue to
use the standard library (per POSIX, they can only portably use
AS-safe functions).
up until recently, taking this allowance did not seem desirable.
however, commit
8ed2bd8bfcb4ea6448afb55a941f4b5b2b0398c0 exposed the
extent to which applications and libraries are depending on the
ability to use malloc and other non-AS-safe interfaces in MT-forked
children, by converting latent very-low-probability catastrophic state
corruption into predictable deadlock. dealing with the fallout has
been a huge burden for users/distros.
while it looks like most of the non-portable usage in applications
could be fixed given sufficient effort, at least some of it seems to
occur in language runtimes which are exposing the ability to run
unrestricted code in the child as part of the contract with the
programmer. any attempt at fixing such contracts is not just a
technical problem but a social one, and is probably not tractable.
this patch extends the fork function to take locks for all libc
singletons in the parent, and release or reset those locks in the
child, so that when the underlying fork operation takes place, the
state protected by these locks is consistent and ready for the child
to use. locking is skipped in the case where the parent is
single-threaded so as not to interfere with legacy AS-safety property
of fork in single-threaded programs. lock order is mostly arbitrary,
but the malloc locks (including bump allocator in case it's used) must
be taken after the locks on any subsystems that might use malloc, and
non-AS-safe locks cannot be taken while the thread list lock is held,
imposing a requirement that it be taken last.
Rich Felker [Wed, 11 Nov 2020 18:08:42 +0000 (13:08 -0500)]
convert malloc use under libc-internal locks to use internal allocator
this change lifts undocumented restrictions on calls by replacement
mallocs to libc functions that might take these locks, and sets the
stage for lifting restrictions on the child execution environment
after multithreaded fork.
care is taken to #define macros to replace all four functions (malloc,
calloc, realloc, free) even if not all of them will be used, using an
undefined symbol name for the ones intended not to be used so that any
inadvertent future use will be caught at compile time rather than
directed to the wrong implementation.
Rich Felker [Wed, 11 Nov 2020 05:22:34 +0000 (00:22 -0500)]
give libc access to its own malloc even if public malloc is interposed
allowing the application to replace malloc (since commit
c9f415d7ea2dace5bf77f6518b6afc36bb7a5732) has brought multiple
headaches where it's used from various critical sections in libc
components. for example:
- the thread-local message buffers allocated for dlerror can't be
freed at thread exit time because application code would then run in
the context of a non-existant thread. this was handled in commit
aa5a9d15e09851f7b4a1668e9dbde0f6234abada by queuing them for free
later.
- the dynamic linker has to be careful not to pass memory allocated at
early startup time (necessarily using its own malloc) to realloc or
free after redoing relocations with the application and all
libraries present. bugs in this area were fixed several times, at
least in commits
0c5c8f5da6e36fe4ab704bee0cd981837859e23f and
2f1f51ae7b2d78247568e7fdb8462f3c19e469a4 and possibly others.
- by calling the allocator from contexts where libc-internal locks are
held, we impose undocumented requirements on alternate malloc
implementations not to call into any libc function that might
attempt to take these locks; if they do, deadlock results.
- work to make fork of a multithreaded parent give the child an
unrestricted execution environment is blocked by lock order issues
as long as the application-provided allocator can be called with
libc-internal locks held.
these problems are all fixed by giving libc internals access to the
original, non-replaced allocator, for use where needed. it can't be
used everywhere, as some interfaces like str[n]dup, open_[w]memstream,
getline/getdelim, etc. are required to provide the called memory
obtained as if by (the public) malloc. and there are a number of libc
interfaces that are "pure library" code, not part of some internal
singleton, and where using the application's choice of malloc
implementation is preferable -- things like glob, regex, etc.
one might expect there to be significant cost to static-linked
programs, pulling in two malloc implementations, one of them
mostly-unused, if malloc is replaced. however, in almost all of the
places where malloc is used internally, care has been taken already
not to pull in realloc/free (i.e. to link with just the bump
allocator). this size optimization carries over automatically.
the newly-exposed internal allocator functions are obtained by
renaming the actual definitions, then adding new wrappers around them
with the public names. technically __libc_realloc and __libc_free
could be aliases rather than needing a layer of wrapper, but this
would almost surely break certain instrumentation (valgrind) and the
size and performance difference is negligible. __libc_calloc needs to
be handled specially since calloc is designed to work with either the
internal or the replaced malloc.
as a bonus, this change also eliminates the longstanding ugly
dependency of the static bump allocator on order of object files in
libc.a, by making it so there's only one definition of the malloc
function and having it in the same source file as the bump allocator.
Rich Felker [Wed, 11 Nov 2020 00:32:09 +0000 (19:32 -0500)]
drop use of getdelim/stdio in dynamic linker
the only place stdio was used here was for reading the ldso path file,
taking advantage of getdelim to automatically allocate and resize the
buffer. the motivation for use here was that, with shared libraries,
stdio is already available anyway and free to use. this has long been
a nuisance to users because getdelim's use of realloc here triggered a
valgrind bug, but removing it doesn't really fix that; on some archs
even calling the valgrind-interposed malloc at this point will crash.
the actual motivation for this change is moving towards getting rid of
use of application-provided malloc in parts of libc where it would be
called with libc-internal locks held, leading to the possibility of
deadlock if the malloc implementation doesn't follow unwritten rules
about which libc functions are safe for it to call. since getdelim is
required to produce a pointer as if by malloc (i.e. that can be passed
to reallor or free), it necessarily must use the public malloc.
instead of performing a realloc loop as the path file is read, first
query its size with fstat and allocate only once. this produces
slightly different truncation behavior when racing with writes to a
file, but neither behavior is or could be made safe anyway; on a live
system, ldso path files should be replaced by atomic rename only. the
change should also reduce memory waste.
Rich Felker [Tue, 10 Nov 2020 19:29:05 +0000 (14:29 -0500)]
dlerror: don't gratuitously hold freebuf_queue lock while freeing
thread-local buffers allocated for dlerror need to be queued for free
at a later time when the owning thread exits, since malloc may be
replaced by application code and the exiting context is not valid to
call application code from. the code to process queue of pending
frees, introduced in commit
aa5a9d15e09851f7b4a1668e9dbde0f6234abada,
gratuitously held the lock for the entire duration of queue
processing, updating the global queue pointer after each free, despite
there being no logical requirement that all frees finish before
another thread can access the queue.
instead, immediately claim the whole queue for freeing and release the
lock, then walk the list and perform frees without the lock held. the
change is unlikely to make any meaningful difference to performance,
but it eliminates one point where the allocator is called under an
internal lock. since the allocator may be application-provided, such
calls are undesirable because they allow application code to impede
forward progress of libc functions in other threads arbitrarily long,
and to induce deadlock if it calls a libc function that requires the
same lock.
the change also eliminates a lock ordering consideration that's an
impediment upcoming work with multithreaded fork.
Rich Felker [Tue, 3 Nov 2020 04:25:12 +0000 (23:25 -0500)]
fix vector types in aarch64 register file structures
the ABI type for the vector registers in fpregset_t, struct
fpsimd_context, and struct user_fpsimd_struct is __uint128_t, which
was presumably originally not used because it's a nonstandard type,
but its existence is mandated by the aarch64 psABI. use of the wrong
type here broke software using these structures, and encouraged
incorrect fixes with casts rather than reinterpretation of
representation.
Rich Felker [Fri, 30 Oct 2020 20:50:08 +0000 (16:50 -0400)]
fix erroneous pthread_cond_wait mutex waiter count logic due to typo
introduced in commit
27b2fc9d6db956359727a66c262f1e69995660aa.
Rich Felker [Fri, 30 Oct 2020 15:21:06 +0000 (11:21 -0400)]
fix missing-wake regression in pthread_cond_wait
the reasoning in commit
2d0bbe6c788938d1332609c014eeebc1dff966ac was
not entirely correct. while it's true that setting the waiters flag
ensures that the next unlock will perform a wake, it's possible that
the wake is consumed by a mutex waiter that has no relationship with
the condvar wait queue being processed, which then takes the mutex.
when that thread subsequently unlocks, it sees no waiters, and leaves
the rest of the condvar queue stuck.
bring back the waiter count adjustment, but skip it for PI mutexes,
for which a successful lock-after-waiting always sets the waiters bit.
if future changes are made to bring this same waiters-bit contract to
all lock types, this can be reverted.
James Y Knight [Mon, 1 Jul 2019 01:55:20 +0000 (21:55 -0400)]
add support for SIGEV_THREAD_ID timers
This is like SIGEV_SIGNAL, but targeted to a particular thread's
tid, rather than the process.
Rich Felker [Wed, 28 Oct 2020 20:13:45 +0000 (16:13 -0400)]
fix sem_close unmapping of still-referenced semaphore
sem_open is required to return the same sem_t pointer for all
references to the same named semaphore when it's opened more than once
in the same process. thus we keep a table of all the mapped semaphores
and their reference counts. the code path for sem_close checked the
reference count, but then proceeded to unmap the semaphore regardless
of whether the count had reached zero.
add an immediate unlock-and-return for the nonzero refcnt case so the
property of performing the munmap syscall after releasing the lock can
be preserved.
Rich Felker [Tue, 27 Oct 2020 05:12:56 +0000 (01:12 -0400)]
refactor setxid return path to use __syscall_ret
this avoids some spurious negation and duplicated errno logic, and
brings the code in line with the newly-added multithreaded setgroups.
rcombs [Sat, 24 Oct 2020 19:31:14 +0000 (14:31 -0500)]
ldso: notify the debugger when we're doing a dlopen
Otherwise lldb doesn't notice the new library and stack traces
containing it get cut off unhelpfully.
Rich Felker [Tue, 27 Oct 2020 04:59:54 +0000 (00:59 -0400)]
fix setgroups behavior in multithreaded process
this function is outside the scope of the standards, but logically
should behave like the set*id functions whose effects are
process-global.
Rich Felker [Tue, 27 Oct 2020 04:45:59 +0000 (00:45 -0400)]
avoid __synccall for setrlimit on kernels with prlimit syscall
resource limits have been process-wide since linux 2.6.10, and the
prlimit syscall was added in 2.6.36, so prlimit can be assumed to set
the resource limits correctly for the whole process.
Rich Felker [Mon, 26 Oct 2020 22:06:18 +0000 (18:06 -0400)]
fix reintroduction of errno clobbering by atfork handlers
commit
bd153422f28634bb6e53f13f80beb8289d405267 reintroduced the bug
fixed in
c21051e90cd27a0b26be0ac66950b7396a156ba1 by refactoring the
__syscall_ret into _Fork where it once again runs before the atfork
handlers are called. since _Fork is a public interface that sets
errno, this can't be fixed the way it was fixed last time without
making new internal interfaces. instead, just save errno, and restore
it only on error to ensure that a value of 0 is never restored.
Rich Felker [Mon, 26 Oct 2020 19:56:25 +0000 (15:56 -0400)]
fix pthread_cond_wait paired with with priority-inheritance mutex
pthread_cond_wait arranged for requeued waiters to wake when the mutex
is unlocked by temporarily adjusting the mutex's waiter count. commit
54ca677983d47529bab8752315ac1a2b49888870 broke this when introducing
PI mutexes by repurposing the waiter count field of the mutex
structure. since then, for PI mutexes, the waiter count adjustment was
misinterpreted by the mutex locking code as indicating that the mutex
is non a non-recoverable state.
it would be possible to special-case PI mutexes here, but instead just
drop all adjustment of the waiters count, and instead use the lock
word waiters bit for all mutex types. since the mutex is either held
by the caller or in unrecoverable state at the time the bit is set, it
will necessarily still be set at the time of any subsequent valid
unlock operation, and this will produce the desired effect of waking
the next waiter.
if waiter counts are entirely dropped at some point in the future this
code should still work without modification.
Rich Felker [Sat, 24 Oct 2020 17:34:29 +0000 (13:34 -0400)]
lift sigaction abort locking to fix posix_spawn child deadlock
commit
25ea9f712c30c32957de493d4711ee39d0bbb024 introduced a deadlock
to the posix_spawn child whereby, if abort was called in the parent
and ended up taking the abort lock to terminate the process, the
__libc_sigaction calls in the child would wait forever to obtain a
lock that would not be released. this could be fixed by having abort
set the abort lock as the exit futex address, but it's cleaner to just
remove the SIGABRT special handling from the internal __libc_sigaction
and lift it to the public sigaction function.
nothing but the posix_spawn child calls __libc_sigaction on SIGABRT,
and since commit
b7bc966522d73e1dc420b5ee6fc7a2e78099a08c the abort
lock is held at the time of __clone, which precludes the child
inheriting a kernel-level signal disposition inconsistent with the
disposition on the abstract machine. this means it's fine to inspect
and modify the disposition in the child without a lock.
Julien Ramseier [Sun, 18 Oct 2020 16:15:06 +0000 (12:15 -0400)]
update crypt_blowfish to support $2b$ prefix
Merge changes from Solar Designer's crypt_blowfish v1.3. This makes
crypt_blowfish fully compatible with OpenBSD's bcrypt by adding
support for the $2b$ prefix (which behaves the same as
crypt_blowfish's $2y$).
Rich Felker [Thu, 15 Oct 2020 00:31:23 +0000 (20:31 -0400)]
remove unused weak definition of __tl_sync in membarrier.c
Rich Felker [Mon, 28 Sep 2020 22:47:13 +0000 (18:47 -0400)]
move aio implementation details to a proper internal header
also fix the lack of declaration (and thus hidden visibility) in
__stdio_close's use of __aio_close.
Rich Felker [Wed, 14 Oct 2020 23:36:03 +0000 (19:36 -0400)]
remove long-unused struct __timer from pthread_impl.h
commit
3990c5c6a40440cdb14746ac080d0ecf8d5d6733 removed the last
reference.
Rich Felker [Wed, 14 Oct 2020 23:07:27 +0000 (19:07 -0400)]
drop use of pthread_once in timer_create
this makes the code slightly smaller and eliminates timer_create from
relevance to possible future changes to multithreaded fork.
the barrier of a_store isn't technically needed here, but a_store is
used anyway for internal consistency of the memory model.
Rich Felker [Wed, 14 Oct 2020 23:04:19 +0000 (19:04 -0400)]
remove unused SIGTIMER handler in timer_create
this was leftover from when the actual SIGEV_THREAD timer logic was in
the signal handler. commit
5b74eed3b301e2227385f3bf26d3bb7c2d822cf8
replaced that with use of sigwaitinfo, with the actual signal left
blocked, so the no-op signal handler was no longer serving any
purpose.
the signal disposition reset to SIG_DFL is still needed, however, in
case we inherited SIG_IGN from a foreign-libc process.
Rich Felker [Wed, 14 Oct 2020 14:55:55 +0000 (10:55 -0400)]
remove incorrect fflush from assert failure handler
assert is not specified to flush open stdio streams, and doing so can
block indefinitely waiting for a lock already held or an output
operation to a file that can't accept more output until an
unsatisfiable condition is met.
Rich Felker [Sun, 11 Oct 2020 00:04:18 +0000 (20:04 -0400)]
fix getgrouplist when nscd reports an empty list
commit
500c6886c654fd45e4926990fee2c61d816be197 broke this by fixing
the behavior of fread to conform to the C standard; getgroupslist was
assuming the old behavior, that a request to read 1 member of length 0
would return 1, not 0.
Rich Felker [Thu, 1 Oct 2020 18:53:12 +0000 (14:53 -0400)]
fix posix_spawn interaction with fork and abort by taking lock
this change prevents the child created concurrently with abort from
seeing the SIGABRT disposition change from SIG_IGN to SIG_DFL (other
changes are not visible anyway) and prevents leaking the write end of
the child pipe to children created by fork in another thread, which
may block return of posix_spawn indefinitely if the forked child does
not exit or exec.
along with other changes, this suggests that __abort_lock should
perhaps eventually be renamed to reflect that it's becoming a broader
lock on related "process lifetime" state.
Rich Felker [Thu, 1 Oct 2020 16:18:18 +0000 (12:18 -0400)]
fix unintended observability of SIGABRT disposition reset via sigaction
the existing abort locking logic in sigaction only accounted for
attempts to change the disposition, not attempts to observe the change
made by abort.
unfortunately the change is still observable in at least one other
place: inheritance of signal dispositions across exec and posix_spawn.
fixing these is a separate task and it's not even clear whether a
complete fix is possible.
Rich Felker [Wed, 30 Sep 2020 17:32:59 +0000 (13:32 -0400)]
implement _Fork and refactor fork using it
the _Fork interface is defined for future issue of POSIX as the
outcome of Austin Group issue 62, which drops the AS-safety
requirement for fork, and provides an AS-safe replacement that does
not run the registered atfork handlers.
Rich Felker [Wed, 30 Sep 2020 17:24:28 +0000 (13:24 -0400)]
rename fork source file
this is in preparation for implementing _Fork from POSIX-future,
factored as a separate commit to improve readability of history.
Rich Felker [Tue, 29 Sep 2020 23:16:19 +0000 (19:16 -0400)]
ldso: use pthread_t rather than kernel tid to track ctor visitor
commit
188759bbee057aa94db2bbb7cf7f5855f3b9ab53 documented the intent
to allow recursive dlopen based on tracking ctor_visitor, but used a
kernel tid rather than the pthread_t to identify the caller. as a
result, it would not behave as intended under fork by a ctor, where
the child tid would not match.
Rich Felker [Tue, 29 Sep 2020 22:42:05 +0000 (18:42 -0400)]
fix stale lock when allocation of ctor queue fails during dlopen
queue_ctors should not be called with the init_fini_lock held, since
it may longjmp out on allocation failure. this introduces a minor
TOCTOU race with p->constructed, but one already exists further down
anyway, and by design it's okay to run through the queue more than
once anyway. the only reason we bother to check p->constructed at all
is to avoid spurious failure of dlopen when the library is already
fully loaded and constructed.
Rich Felker [Tue, 29 Sep 2020 18:02:06 +0000 (14:02 -0400)]
drop use of pthread_once in mutexattr kernel support tests
this makes the code slightly smaller and eliminates these functions
from relevance to possible future changes to multithreaded fork.
the barrier of a_store isn't technically needed here, but a_store is
used anyway for internal consistency of the memory model.
Rich Felker [Mon, 28 Sep 2020 23:32:34 +0000 (19:32 -0400)]
fix missing synchronization of fork with abort
if the multithreaded parent forked while another thread was calling
sigaction for SIGABRT or calling abort, the child could inherit a lock
state in which future calls to abort will deadlock, or in which the
disposition for SIGABRT has already been reset to SIG_DFL. this is
nonconforming since abort is AS-safe and permitted to be called
concurrently with fork or in the MT-forked child.
Rich Felker [Mon, 28 Sep 2020 23:30:19 +0000 (19:30 -0400)]
move __abort_lock to its own file and drop pointless weak_alias trick
the dummy definition of __abort_lock in sigaction.c was performing
exactly the same role that putting the lock in its own source file
could and should have been used to achieve.
while we're moving it, give it a proper declaration.
Rich Felker [Mon, 28 Sep 2020 22:38:27 +0000 (18:38 -0400)]
fix fork of processes with active async io contexts
previously, if a file descriptor had aio operations pending in the
parent before fork, attempting to close it in the child would attempt
to cancel a thread belonging to the parent. this could deadlock, fail,
or crash the whole process of the cancellation signal handler was not
yet installed in the parent. in addition, further use of aio from the
child could malfunction or deadlock.
POSIX specifies that async io operations are not inherited by the
child on fork, so clear the entire aio fd map in the child, and take
the aio map lock (with signals blocked) across the fork so that the
lock is kept in a consistent state.
Rich Felker [Thu, 17 Sep 2020 19:09:46 +0000 (15:09 -0400)]
avoid set*id/setrlimit misbehavior and hang in vforked/cloned child
taking the deprecated/dropped vfork spec strictly, doing pretty much
anything but execve in the child is wrong and undefined. however,
these are commonly needed operations to setup the child state before
exec, and historical implementations tolerated them.
for single-threaded parents, these operations already worked as
expected in the vforked child. however, due to the need for __synccall
to synchronize id/resource limit changes among all threads, calling
these functions in the vforked child of a multithreaded parent caused
a misdirected broadcast signaling of all threads in the parent. these
signals could kill the parent entirely if the synccall signal handler
had never been installed in the parent, or could be ignored if it had,
or could signal/kill one or more utterly wrong processes if the parent
already terminated (due to vfork semantics, only possible via fatal
signal) and the parent tids were recycled. in any case, the expected
number of semaphore posts would never happen, so the child would
permanently hang (with all signals blocked) waiting for them.
to mitigate this, and also make the normal usage case work as
intended, treat the condition where the caller's actual tid does not
match the tid in its thread structure as single-threaded, and bypass
the entire synccall broadcast operation.
Rich Felker [Thu, 10 Sep 2020 01:55:11 +0000 (21:55 -0400)]
use new SYS_faccessat2 syscall to implement faccessat with flags
commit
0a05eace163cee9b08571d2ff9d90f5e82d9c228 implemented AT_EACCESS
for faccessat with a horrible hack, creating a child process to change
switch uid/gid and perform the access probe without making potentially
irreversible changes to the caller's credentials. this was due to the
syscall lacking a flags argument.
linux 5.8 introduced a new syscall, SYS_faccessat2, fixing this
deficiency. use it if any flags are passed, and fallback to the old
strategy on ENOSYS. continue using the old syscall when there are no
flags.
Szabolcs Nagy [Wed, 9 Sep 2020 07:33:47 +0000 (07:33 +0000)]
netinet/if_ether.h: add ETH_P_MRP from linux v5.8
Ethernet protocol number for media redundancy protocol, see
linux commit
4714d13791f831d253852c8b5d657270becb8b2a
bridge: uapi: mrp: Add mrp attributes.
Szabolcs Nagy [Wed, 9 Sep 2020 07:25:52 +0000 (07:25 +0000)]
elf.h: add .note.gnu.property related definitions
On x86 and aarch64 GNU properties may be used to mark ELF objects.
Szabolcs Nagy [Tue, 28 Jul 2020 21:17:13 +0000 (21:17 +0000)]
bits/syscall.h: add __NR_faccessat2 from linux v5.8
the linux faccessat syscall lacks a flag argument that is necessary
to implement the posix api, see
linux commit
c8ffd8bcdd28296a198f237cc595148a8d4adfbe
vfs: add faccessat2 syscall
Szabolcs Nagy [Mon, 13 Jul 2020 19:59:41 +0000 (19:59 +0000)]
netinet/tcp.h: update to linux v5.7
add TCP_NLA_BYTES_NOTSENT and new tcp_zerocopy_receive fields, see
linux commit
c8856c051454909e5059df4e81c77b9c366c5515
tcp-zerocopy: Return inq along with tcp receive zerocopy.
linux commit
33946518d493cdf10aedb4a483f1aa41948a3dab
tcp-zerocopy: Return sk_err (if set) along with tcp receive zerocopy.
linux commit
e08ab0b377a1489760533424437c5f4be7f484a4
tcp: add bytes not sent to SCM_TIMESTAMPING_OPT_STATS
Szabolcs Nagy [Mon, 13 Jul 2020 19:43:44 +0000 (19:43 +0000)]
sys/mman.h: add MREMAP_DONTUNMAP from linux v5.7
it remaps anon mappings without unmapping the original. chromeos plans
to use it with userfaultfd, see:
linux commit
e346b3813067d4b17383f975f197a9aa28a3b077
mm/mremap: add MREMAP_DONTUNMAP to mremap()
Szabolcs Nagy [Mon, 13 Jul 2020 19:38:27 +0000 (19:38 +0000)]
sys/fanotify.h: update to linux v5.7
see
linux commit
9e2ba2c34f1922ca1e0c7d31b30ace5842c2e7d1
fanotify: send FAN_DIR_MODIFY event flavor with dir inode and name
linux commit
44d705b0370b1d581f46ff23e5d33e8b5ff8ec58
fanotify: report name info for FAN_DIR_MODIFY event
Szabolcs Nagy [Tue, 31 Mar 2020 20:57:46 +0000 (20:57 +0000)]
aarch64: add new HWCAP2_ macros from linux v5.6
added in
linux commit
1a50ec0b3b2e9a83f1b1245ea37a853aac2f741c
arm64: Implement archrandom.h for ARMv8.5-RNG
linux commit
d4209d8b717311d114b5d47ba7f8249fd44e97c2
arm64: cpufeature: Export matrix and other features to userspace
Szabolcs Nagy [Tue, 31 Mar 2020 20:57:46 +0000 (20:57 +0000)]
aarch64: add HWCAP2_ macros from linux v5.3
these were missed before, added in
linux commit
1201937491822b61641c1878ebcd16a93aed4540
arm64: Expose ARMv8.5 CondM capability to userspace
linux commit
ca9503fc9e9812aa6258e55d44edb03eb30fc46f
arm64: Expose FRINT capabilities to userspace