| Commit message (Collapse) | Author | Files | Lines |
|---|
|
while it's not clearly documented anywhere, this is the historical
behavior which some applications expect. applications which need to
see the response packet in these cases, for example to distinguish
between nonexistence in a secure vs insecure zone, must already use
res_mkquery with res_send in order to be portable, since most if not
all other implementations of res_query don't provide it.
|
|
the framework to do this always existed but it was deemed unnecessary
because the only [ex-]standard functions using h_errno were not
thread-safe anyway. however, some of the nonstandard res_* functions
are also supposed to set h_errno to indicate the cause of error, and
were unable to do so because it was not thread-safe. this change is a
prerequisite for fixing them.
|
|
these have been adopted for future issue of POSIX as the outcome of
Austin Group issue 1151, and are simply functions performing the roles
of the historical ioctls. since struct winsize is being standardized
along with them, its definition is moved to the appropriate header.
there is some chance this will break source files that expect struct
winsize to be defined by sys/ioctl.h without including termios.h. if
this happens, further changes will be needed to have sys/ioctl.h
expose it too.
|
|
all path elements but the last had the final byte truncated.
|
|
this is a prerequisite for addition of other interfaces that use
kernel tids, including futex and SIGEV_THREAD_ID.
there is some ambiguity as to whether the semantic return type should
be int or pid_t. either way, futex API imposes a contract that the
values fit in int (excluding some upper reserved bits). glibc used
pid_t, so in the interest of not having gratuitous mismatch (the
underlying types are the same anyway), pid_t is used here as well.
while conceptually this is a syscall, the copy stored in the thread
structure is always valid in all contexts where it's valid to call
libc functions, so it's used to avoid the syscall.
|
|
longjmp should set the return value of setjmp, but 64bit
registers were used for the 0 check while the type is int.
use the code that gcc generates for return val ? val : 1;
|
|
Use a branchless sequence that is one byte shorter on 64-bit, same size
on 32-bit. Thanks to Pete Cawley for suggesting this variant.
|
|
|
|
|
|
longjmp 'val' argument is an int, but the assembly is referencing 64-bit
registers as if the argument was a long, or the caller was responsible
for extending the argument. Though the psABI is not clear on this, the
interpretation in GCC is that high bits may be arbitrary and the callee
is responsible for sign/zero-extending the value as needed (likewise for
return values: callers must anticipate that high bits may be garbage).
Therefore testing %rax is a functional bug: setjmp would wrongly return
zero if longjmp was called with val==0, but high bits of %rsi happened
to be non-zero.
Rewrite the prologue to refer to 32-bit registers. In passing, change
'test' to use %rsi, as there's no advantage to using %rax and the new
form is cheaper on processors that do not perform move elimination.
|
|
a number of users performing seccomp filtering have requested use of
the new individual syscall numbers for socket syscalls, rather than
the legacy multiplexed socketcall, since the latter has the arguments
all in memory where they can't participate in filter decisions.
previously, some archs used the multiplexed socketcall if it was
historically all that was available, while other archs used the
separate syscalls. the intent was that the latter set only include
archs that have "always" had separate socket syscalls, at least going
back to linux 2.6.0. however, at least powerpc, powerpc64, and sh were
wrongly included in this set, and thus socket operations completely
failed on old kernels for these archs.
with the changes made here, the separate syscalls are always
preferred, but fallback code is compiled for archs that also define
SYS_socketcall. two such archs, mips (plain o32) and microblaze,
define SYS_socketcall despite never having needed it, so it's now
undefined by their versions of syscall_arch.h to prevent inclusion of
useless fallback code.
some archs, where the separate syscalls were only added after the
addition of SYS_accept4, lack SYS_accept. because socket calls are
always made with zeros in the unused argument positions, it suffices
to just use SYS_accept4 to provide a definition of SYS_accept, and
this is done to make happy the macro machinery that concatenates the
socket call name onto __SC_ and SYS_.
|
|
same approach as in sqrt.
sqrtl was broken on aarch64, riscv64 and s390x targets because
of missing quad precision support and on m68k-sf because of
missing ld80 sqrtl.
this implementation is written for quad precision and then
edited to make it work for both m68k and x86 style ld80 formats
too, but it is not expected to be optimal for them.
note: using fp instructions for the initial estimate when such
instructions are available (e.g. double prec sqrt or rsqrt) is
avoided because of fenv correctness.
|
|
for targets where long double is different from double.
|
|
same method as in sqrt, this was tested on all inputs against
an sqrtf instruction. (the only difference found was that x86
sqrtf does not signal the x86 specific input-denormal exception
on negative subnormal inputs while the software sqrtf does,
this is fine as it was designed for ieee754 exceptions only.)
there is known faster method:
"Computing Floating-Point Square Roots via Bivariate Polynomial Evaluation"
that computes sqrtf directly via pipelined polynomial evaluation
which allows more parallelism, but the design does not generalize
easily to higher precisions.
|
|
approximate 1/sqrt(x) and sqrt(x) with goldschmidt iterations.
this is known to be a fast method for computing sqrt, but it is
tricky to get right, so added detailed comments.
use a lookup table for the initial estimate, this adds 256bytes
rodata but it can be shared between sqrt, sqrtf and sqrtl.
this saves one iteration compared to a linear estimate.
this is for soft float targets, but it supports fenv by using a
floating-point operation to get the final result. the result
is correctly rounded in all rounding modes. if fenv support is
turned off then the nearest rounded result is computed and
inexact exception is not signaled.
assumes fast 32bit integer arithmetics and 32 to 64bit mul.
|
|
prior to this change, the canonical name came from the first hosts
file line matching the requested family, so the canonical name for a
given hostname could differ depending on whether it was requested with
AF_UNSPEC or a particular family (AF_INET or AF_INET6). now, the
canonical name is deterministically the first one to appear with the
requested name as an alias.
|
|
the existing code clobbered the canonical name already discovered
every time another matching line was found, which will necessarily be
the case when a hostname has both IPv4 and v6 definitions.
patch by Wolf.
|
|
|
