the input name is validated, the other parameters are assumed to be
valid (the list of already compressed names are not checked for
infinite reference loops or out-of-bound offsets).
names are handled case-sensitively for now.
trailing . should be accepted in domain name strings by convention
(RFC 1034), host name lookup accepts "." but rejects empty "", res_*
interfaces also accept empty name following existing practice.
Due to an error introduced in commit fcc522c923,
checking of the remaining output buffer space was not performed correctly,
allowing malformed input to write past the end of the buffer.
In addition, the loop detection logic failed to account for the possibility
of infinite loops with no output, which would hang the function.
The output size is now limited more strictly so only names with valid length
are accepted.
from linux/in.h and linux/in6.h uapi headers the following
missing socket options were added:
IP_NODEFRAG - used with customized ipv4 headers
IPV6_RECVPATHMTU - for ipv6 path mtu
IPV6_PATHMTU - for ipv6 path mtu
IPV6_DONTFRAG - for ipv6 path mtu
IPV6_ADDR_PREFERENCES - RFC5014 Source Address Selection
IPV6_MINHOPCOUNT - RFC5082 Generalized TTL Security Mechanism
IPV6_ORIGDSTADDR - used by tproxy
IPV6_RECVORIGDSTADDR - used by tproxy
IPV6_TRANSPARENT - used by tproxy
IPV6_UNICAST_IF - ipv6 version of IP_UNICAST_IF
and socket option values:
IP_PMTUDISC_OMIT - value for IP_MTU_DISCOVER option, new in linux 3.14
IPV6_PMTUDISC_OMIT - same for IPV6_MTU_DISCOVER
IPV6_PMTUDISC_INTERFACE - ipv6 version of IP_PMTUDISC_INTERFACE
IPV6_PREFER_* - flags for IPV6_ADDR_PREFERENCES
not added: ipv6 flow info and flow label related definitions.
(it's unclear if libc should define these and namespace polluting
type name is involved so they are not provided for now)
linux 3.14 introduced sched_getattr and sched_setattr syscalls in
commit d50dde5a10f305253cbc3855307f608f8a3c5f73
and the related SCHED_DEADLINE scheduling policy in
commit aab03e05e8f7e26f51dee792beddcb5cca9215a5
but struct sched_attr "extended scheduling parameters data structure"
is not yet exported to userspace (necessary for using the syscalls)
so related uapi definitions are not added yet.
On 32 bit mips the kernel uses -1UL/2 to mark RLIM_INFINITY (and
this is the definition in the userspace api), but since it is in
the middle of the valid range of limits and limits are often
compared with relational operators, various kernel side logic is
broken if larger than -1UL/2 limits are used. So we truncate the
limits to -1UL/2 in get/setrlimit and prlimit.
Even if the kernel side logic consistently treated -1UL/2 as greater
than any other limit value, there wouldn't be any clean workaround
that allowed using large limits:
* using -1UL/2 as RLIM_INFINITY in userspace would mean different
infinity value for get/setrlimt and prlimit (where infinity is always
-1ULL) and userspace logic could break easily (just like the kernel
is broken now) and more special case code would be needed for mips.
* translating -1UL/2 kernel side value to -1ULL in userspace would
mean that -1UL/2 limit cannot be set (eg. -1UL/2+1 had to be passed
to the kernel instead).
The mips arch is special in that it uses different RLIMIT_
numbers than other archs, so allow bits/resource.h to override
the default RLIMIT_ numbers (empty on all archs except mips).
Reported by orc.
modfl and sincosl were passing long double* instead of double*
to the wrapped double precision functions (on archs where long
double and double have the same size).
This is fixed now by using temporaries (this is not optimized
to a single branch so the generated code is a bit bigger).
Found by Morten Welinder.
The mips statfs struct layout is different than on other archs, so the
statfs, fstatfs, statvfs and fstatvfs APIs were broken on mips.
Now the ordering is fixed, the types are kept consistent with other archs.
Userspace emulated floating-point (gcc -msoft-float) is not compatible
with the default mips abi (assumes an FPU or in kernel emulation of it).
Soft vs hard float abi should not be mixed, __mips_soft_float is checked
in musl's configure script and there is no runtime check. The -sf subarch
does not save/restore floating-point registers in setjmp/longjmp and only
provides dummy fenv implementation.
gcc -Wsign-compare warns about expanded macros that were defined in
standard headers (before gcc 4.8) which can make builds fail that
use -Werror. changed macros: WIFSIGNALED, __CPU_op_S
the default fenv was not set up properly, in particular the
tag word that indicates the contents of the x87 registers was
set to 0 (used) instead of 0xffff (empty)
this could cause random crashes after setting the default fenv
because it corrupted the fpu stack and then any float computation
gives NaN result breaking the program logic (usually after a
float to integer conversion).
setstate could use the results of previous initstate or setstate
calls (they return the old state buffer), but the documentation
requires that an initialized state buffer should be possible to
use in setstate immediately, which means that initstate should
save the generator parameters in it.
I also removed the copyright notice since it is present in the
copyright file.
historically these functions appeared in BSD 4.3 without prototypes,
then in the bind project prototypes were added to resolv.h, but those
were incompatible with the definitions of the implementation.
the bind resolv.h became the defacto api most systems use now, but the
old internal definitions found their way into the linux manuals and thus
into musl.
a '/' in the pattern could be incorrectly matched against the
terminating null byte in the string causing arbitrarily long
sequence of out-of-bounds access in fnmatch("/","",FNM_PATHNAME)
- remove the HAVE_EFFICIENT_IRINT case: fn is an exact integer, so
it can be converted to int32_t a bit more efficiently than with a
cast (the rounding mode change can be avoided), but musl does not
support this case on any arch.
- __rem_pio2: use double_t where possible
- __rem_pio2f: use less assignments to avoid stores on i386
- use unsigned int bit manipulation (and union instead of macros)
- use hexfloat literals instead of named constants
* simplify sin_pi(x) (don't care about inexact here, the result is
inexact anyway, and x is not so small to underflow)
* in lgammal add the previously removed special case for x==1 and
x==2 (to fix the sign of zero in downward rounding mode)
* only define lgammal on supported long double platforms
* change tgamma so the generated code is a bit smaller
i386 fenv code checks __hwcap for sse support, but in fesetround the sse
code was unconditionally jumped over after the test so the sse rounding
mode was never set.
The log, log2 and log10 functions share a lot of code and to a lesser
extent log1p too. A small part of the code was kept separately in
__log1p.h, but since it did not capture much of the common code and
it was inlined anyway, it did not solve the issue properly. Now the
log functions have significant code duplication, which may be resolved
later, until then they need to be modified together.
logl, log10l, log2l, log1pl:
* Fix the sign when the return value should be -inf.
* Remove the volatile hack from log10l (seems unnecessary)
log1p, log1pf:
* Change the handling of small inputs: only |x|<2^-53 is special
(then it is enough to return x with the usual subnormal handling)
this fixes the sign of log1p(0) in downward rounding.
* Do not handle the k==0 case specially (other than skipping the
elaborate argument reduction)
* Do not handle 1+x close to power-of-two specially (this code was
used rarely, did not give much speed up and the precision wasn't
better than the general)
* Fix the correction term formula (c=1-(u-x) was used incorrectly
when x<1 but (double)(x+1)==2, this was not a critical issue)
* Use the exact same method for calculating log(1+f) as in log
(except in log1p the c correction term is added to the result).
log, logf, log10, log10f, log2, log2f:
* Use double_t and float_t consistently.
* Now the first part of log10 and log2 is identical to log (until the
return statement, hopefully this makes maintainence easier).
* Most special case formulas were removed (close to power-of-two and
k==0 cases), they increase the code size without providing precision
or performance benefits (and obfuscate the code).
Only x==1 is handled specially so in downward rounding mode the
sign of zero is correct (the general formula happens to give -0).
* For x==0 instead of -1/0.0 or -two54/0.0, return -1/(x*x) to force
raising the exception at runtime.
* Arg reduction code is changed (slightly simplified)
* The thresholds for arg reduction to [sqrt(2)/2,sqrt(2)] are now
consistently the [0x3fe6a09e00000000,0x3ff6a09dffffffff] and the
[0x3f3504f3,0x3fb504f2] intervals for double and float reductions
respectively (the exact threshold values are not critical)
* Remove the obsolete comment for the FLT_EVAL_METHOD!=0 case in log2f
(The same code is used for all eval methods now, on i386 slightly
simpler code could be used, but we have asm there anyway)
all:
* Fix signed int arithmetics (using unsigned for bitmanipulation)
* Fix various comments
* parse IPv4 dotted-decimal correctly (without strtoul, no leading zeros)
* disallow single leading ':' in IPv6 address
* allow at most 4 hex digits in IPv6 address (according to RFC 2373)
* have enough hex fields in IPv4 mapped IPv6 address
* disallow leading zeros in IPv4 mapped IPv6 address
* allow at most 4 parts
* bounds check the parts correctly
* disallow leading whitespace and sign
* check the address family before falling back to IPv6
This is a change in ISO C11 annex F (F.10.11p1), comparision macros
can't round their arguments to their semantic type when the evaluation
format has wider range and precision. (ie. they must be consistent with
the builtin relational operators)
These constants are not specified by POSIX, but they are in the reserved
namespace, glibc and bsd systems seem to provide them as well.
(Note that POSIX specifies -NZERO and NZERO-1 to be the limits, but
PRIO_MAX equals NZERO)
the changes were verified using various sources:
linux: include/uapi/linux/elf.h
binutils: include/elf/common.h
glibc: elf/elf.h
sysv gabi: http://www.sco.com/developers/gabi/latest/contents.html
sun linker docs: http://docs.oracle.com/cd/E18752_01/pdf/817-1984.pdf
and platform specific docs
- fixed:
EF_MIPS_* E_MIPS_* e_flags: fixed accoding to glibc and binutils
- added:
ELFOSABI_GNU for EI_OSABI entry: glibc, binutils and sysv gabi
EM_* e_machine values: updated according to linux and glibc
PN_XNUM e_phnum value: from glibc and linux, see oracle docs
NT_* note types: updated according to linux and glibc
DF_1_* flags for DT_FLAGS_1 entry: following glibc and oracle docs
AT_HWCAP2 auxv entry for more hwcap bits accoding to linux and glibc
R_386_SIZE32 relocation according to glibc and binutils
EF_ARM_ABI_FLOAT_* e_flags: added following glibc and binutils
R_AARCH64_* relocs: added following glibc and aarch64 elf specs
R_ARM_* relocs: according to glibc, binutils and arm elf specs
R_X86_64_* relocs: added missing relocs following glibc
- removed:
HWCAP_SPARC_* flags were moved to arch specific header in glibc
R_ARM_SWI24 reloc is marked as obsolete in glibc, not present in binutils
not specified in arm elf spec, R_ARM_TLS_DESC reused its number
see http://www.codesourcery.com/publications/RFC-TLSDESC-ARM.txt
- glibc changes not pulled in:
ELFOSABI_ARM_AEABI (bare-metal system, binutils and glibc disagrees about the name)
R_68K_* relocs for unsupported platform
R_SPARC_* ditto
EF_SH* ditto (e_flags)
EF_S390* ditto (e_flags)
R_390* ditto
R_MN10300* ditto
R_TILE* ditto
the removed ARPHRD_IEEE802154_PHY was only present in the kernel api
in v2.6.31 (by accident), but it got into the glibc headers (in 2009)
and remained there since this header was not updated since then.
PAGE_SIZE was hardcoded to 4096, which is historically what most
systems use, but on several archs it is a kernel config parameter,
user space can only know it at execution time from the aux vector.
PAGE_SIZE and PAGESIZE are not defined on archs where page size is
a runtime parameter, applications should use sysconf(_SC_PAGE_SIZE)
to query it. Internally libc code defines PAGE_SIZE to libc.page_size,
which is set to aux[AT_PAGESZ] in __init_libc and early in __dynlink
as well. (Note that libc.page_size can be accessed without GOT, ie.
before relocations are done)
Some fpathconf settings are hardcoded to 4096, these should be actually
queried from the filesystem using statfs.
gcc did not always drop excess precision according to c99 at assignments
before version 4.5 even if -std=c99 was requested which caused badly
broken mathematical functions on i386 when FLT_EVAL_METHOD!=0
but STRICT_ASSIGN was not used consistently and it is worked around for
old compilers with -ffloat-store so it is no longer needed
the new convention is to get the compiler respect c99 semantics and when
excess precision is not harmful use float_t or double_t or to specialize
code using FLT_EVAL_METHOD
apparently gnulib requires invalid long double representations
to be handled correctly in printf so we classify them according
to how the fpu treats them: bad inf is nan, bad nan is nan,
bad normal is nan and bad subnormal/zero is minimal normal
in atanh exception handling was left to the called log functions,
but the argument to those functions could underflow or overflow.
use double_t and float_t to avoid some useless stores on x86
acosh(x) is invalid for x<1, acoshf tried to be clever using
signed comparisions to handle all x<2 the same way, but the
formula was wrong on large negative values.
there were two problems:
* omitted underflow on subnormal results: exp2l(-16383.5) was calculated
as sqrt(2)*2^-16384, the last bits of sqrt(2) are zero so the down scaling
does not underflow eventhough the result is in subnormal range
* spurious underflow for subnormal inputs: exp2l(0x1p-16400) was evaluated
as f2xm1(x)+1 and f2xm1 raised underflow (because inexact subnormal result)
the first issue is fixed by raising underflow manually if x is in
(-32768,-16382] and not integer (x-0x1p63+0x1p63 != x)
the second issue is fixed by treating x in (-0x1p64,0x1p64) specially
for these fixes the special case handling was completely rewritten
* use float_t and double_t
* cleanup subnormal handling
* bithacks according to the new convention (ldshape for long double
and explicit unions for float and double)
* don't care about inexact flag
* use double_t and float_t (faster, smaller, more precise on x86)
* exp: underflow when result is zero or subnormal and not -inf
* exp2: underflow when result is zero or subnormal and not exact
* expm1: underflow when result is zero or subnormal
* expl: don't underflow on -inf
* exp2: fix incorrect comment
* expm1: simplify special case handling and overflow properly
* expm1: cleanup final scaling and fix negative left shift ub (twopk)
ld128 support was added to internal kernel functions (__cosl, __sinl,
__tanl, __rem_pio2l) from freebsd (not tested, but should be a good
start for when ld128 arch arrives)
__rem_pio2l had some code cleanup, the freebsd ld128 code seems to
gather the results of a large reduction with precision loss (fixed
the bug but a todo comment was added for later investigation)
the old copyright was removed from the non-kernel wrapper functions
(cosl, sinl, sincosl, tanl) since these are trivial and the interesting
parts and comments had been already rewritten.
method: if there is a large difference between the scale of x and y
then the larger magnitude dominates, otherwise reduce x,y so the
argument of sqrt (x*x+y*y) does not overflow or underflow and calculate
the argument precisely using exact multiplication. If the argument
has less error than 1/sqrt(2) ~ 0.7 ulp, then the result has less error
than 1 ulp in nearest rounding mode.
the original fdlibm method was the same, except it used bit hacks
instead of dekker-veltkamp algorithm, which is problematic for long
double where different representations are supported. (the new hypot
and hypotl code should be smaller and faster on 32bit cpu archs with
fast fpu), the new code behaves differently in non-nearest rounding,
but the error should be still less than 2ulps.
ld80 and ld128 are supported
* results are exact
* modfl follows truncl (raises inexact flag spuriously now)
* modf and modff only had cosmetic cleanup
* remainder is just a wrapper around remquo now
* using iterative shift+subtract for remquo and fmod
* ld80 and ld128 are supported as well
* faster, smaller, cleaner implementation than the bit hacks of fdlibm
* use arithmetics like y=(double)(x+0x1p52)-0x1p52, which is an integer
neighbor of x in all rounding modes (0<=x<0x1p52) and only use bithacks
when that's faster and smaller (for float it usually is)
* the code assumes standard excess precision handling for casts
* long double code supports both ld80 and ld128
* nearbyint is not changed (it is a wrapper around rint)
* consistent code style
* explicit union instead of typedef for double and float bit access
* turn FENV_ACCESS ON to make 0/0.0f raise invalid flag
* (untested) ld128 version of ilogbl (used by logbl which has ld128 support)
new ldshape union, ld128 support is kept, code that used the old
ldshape union was rewritten (IEEEl2bits union of freebsd libm is
not touched yet)
ld80 __fpclassifyl no longer tries to handle invalid representation
fesetround.c is a wrapper to do the arch independent argument
check (on archs where rounding mode is not stored in 2 bits
__fesetround still has to check its arguments)
on powerpc fe*except functions do not accept the extra invalid
flags of its fpscr register
the useless FENV_ACCESS pragma was removed from feupdateenv
the x87 exception summary (ES) and stack fault (SF) flags may be
spuriously cleared by feclearexcept using the fnclex instruction,
but these flags are not observable through libc hence maintaining
their state is not critical.
the sse and x87 rounding modes should be always the same,
the visible exception flags are the bitwise or of the two
fenv states (so it's enough to query the rounding mode or
raise exceptions on one fenv)
Szabolcs Nagy