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Szabolcs Nagy [Sun, 24 Jan 2016 01:19:38 +0000 (01:19 +0000)]
add MCL_ONFAULT and MLOCK_ONFAULT mlockall and mlock2 flags
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
Szabolcs Nagy [Sat, 23 Jan 2016 23:16:14 +0000 (23:16 +0000)]
add mlock2 syscall number from linux v4.4
this is mlock with a flags argument, new in linux commit
a8ca5d0ecbdde5cc3d7accacbd69968b0c98764e
as usual microblaze and sh don't have allocated syscall number yet.
Szabolcs Nagy [Thu, 19 Nov 2015 00:01:17 +0000 (00:01 +0000)]
add new PTRACE_O_SUSPEND_SECCOMP ptrace option
allows a ptracer process to disable/enable seccomp filters of the
traced process, useful for checkpoint/restore, new in v4.3 commit
13c4a90119d28cfcb6b5bdd820c233b86c2b0237
Szabolcs Nagy [Wed, 18 Nov 2015 23:56:08 +0000 (23:56 +0000)]
add new PR_CAP_AMBIENT and related defines to sys/prctl.h
ambient capability mask is new in linux v4.3, commit
58319057b7847667f0c9585b9de0e8932b0fdb08
Szabolcs Nagy [Wed, 18 Nov 2015 23:54:22 +0000 (23:54 +0000)]
update netpacket/packet.h to linux v4.3
Szabolcs Nagy [Wed, 18 Nov 2015 23:31:37 +0000 (23:31 +0000)]
add new membarrier, userfaultfd and switch_endian syscalls
new in linux v4.3 added for aarch64, arm, i386, mips, or1k, powerpc,
x32 and x86_64.
membarrier is a system wide memory barrier, moves most of the
synchronization cost to one side, new in kernel commit
5b25b13ab08f616efd566347d809b4ece54570d1
userfaultfd is useful for qemu and is new in kernel commit
8d2afd96c20316d112e04d935d9e09150e988397
switch_endian is powerpc only for switching endianness, new in commit
529d235a0e190ded1d21ccc80a73e625ebcad09b
Szabolcs Nagy [Wed, 18 Nov 2015 23:27:07 +0000 (23:27 +0000)]
add new i386 socket syscall numbers
new in linux v4.3 commit
9dea5dc921b5f4045a18c63eb92e84dc274d17eb
direct calls instead of socketcall allow better seccomp filtering.
musl continues to use socketcalls internally on i386. (older kernels
would need a fallback mechanism if the direct calls were used.)
Szabolcs Nagy [Mon, 25 Jan 2016 00:52:58 +0000 (00:52 +0000)]
change the internal socketcall selection logic
only use SYS_socketcall if SYSCALL_USE_SOCKETCALL is defined
internally, otherwise use direct syscalls.
this commit does not change the current behaviour, it is
preparation for adding direct syscall numbers for i386.
Rich Felker [Tue, 26 Jan 2016 01:06:31 +0000 (20:06 -0500)]
add ssp suppression to some arch-override files that may need it
these were not covered by the parent-level rules with the new build
system. in the old build system, the equivalent files were often in
arch/$(ARCH)/src and likewise lacked the suppression. this could lead
to early crashing (before thread pointer init) when libc itself was
built with stack protector enabled.
Rich Felker [Tue, 26 Jan 2016 00:57:38 +0000 (19:57 -0500)]
use same object files for libc.a and libc.so if compiler produces PIC
now that .lo and .o files differ only by whether -fPIC is passed (and
no longer at the source level based on the SHARED macro), it's
possible to use the same object files for both static and shared libc
when the compiler would produce PIC for the static files anyway. this
happens if the user has included -fPIC in their CFLAGS or if the
compiler has been configured to produce PIE by default.
we use the .lo files for both, and still append -fPIC to the CFLAGS,
rather than using the .o files so that libc.so does not break
catastrophically if the user later removes -fPIC from CFLAGS in
config.mak or on the make command line. this also ensures that we get
full -fPIC in case -fpic, -fPIE, or some other lesser-PIC option was
passed in CFLAGS.
Rich Felker [Tue, 26 Jan 2016 00:29:55 +0000 (19:29 -0500)]
move dynamic linker to its own top-level directory, ldso
this eliminates the last need for the SHARED macro to control how
files in the src tree are compiled. the same code is used for both
libc.a and libc.so, with additional code for the dynamic linker (from
the new ldso tree) being added to libc.so but not libc.a. separate .o
and .lo object files still exist for the src tree, but the only
difference is that the .lo files are built as PIC.
in the future, if/when we add dlopen support for static-linked
programs, much of the code in dynlink.c may be moved back into the src
tree, but properly factored into separate source files. in that case,
the code in the ldso tree will be reduced to just the dynamic linker
entry point, self-relocation, and loading of libraries needed by the
main application.
Rich Felker [Tue, 26 Jan 2016 00:12:41 +0000 (19:12 -0500)]
adapt static dl_iterate_phdr not to depend on !defined(SHARED)
like elsewhere, use a weak alias that the dynamic linker will override
with a more complete version capable of handling shared libraries.
Rich Felker [Tue, 26 Jan 2016 00:01:22 +0000 (19:01 -0500)]
move static-linked stub dlsym out of dynlink.c
the function name is still __-prefixed because it requires an asm
wrapper to pass the caller's address in order for RTLD_NEXT to work.
since this was the last function in dynlink.c still used for static
linking, now the whole file is conditional on SHARED being defined.
Rich Felker [Mon, 25 Jan 2016 23:58:06 +0000 (18:58 -0500)]
move static-linked stub dlopen out of dynlink.c
Rich Felker [Mon, 25 Jan 2016 23:55:35 +0000 (18:55 -0500)]
move dlinfo out of dynlink.c
Rich Felker [Mon, 25 Jan 2016 23:53:40 +0000 (18:53 -0500)]
move dlclose out of dynlink.c to its own source file
Rich Felker [Mon, 25 Jan 2016 23:51:33 +0000 (18:51 -0500)]
move static-linked stub invalid dso handle checking out of dynlink.c
Rich Felker [Mon, 25 Jan 2016 23:37:05 +0000 (18:37 -0500)]
move static/stub version of dladdr out of dynlink.c
Rich Felker [Mon, 25 Jan 2016 22:56:00 +0000 (17:56 -0500)]
factor dlerror and error-setting code out of dynlink.c
the ultimate goal of this change is to get all code used in libc.a out
of dynlink.c, so that the dynamic linker code can be moved to its own
tree and object files in the src tree can all be shared between libc.a
and libc.so.
Rich Felker [Mon, 25 Jan 2016 21:59:55 +0000 (21:59 +0000)]
fix arm a_crash for big endian
contrary to commit
89e149d275a7699a4a5e4c98bab267648f64cbba, big
endian arm does need the instruction bytes in big endian order. rather
than trying to use a special encoding that works as arm or thumb,
simply encode the simplest/canonical undefined instructions dependent
on whether __thumb__ is defined.
Rich Felker [Mon, 25 Jan 2016 02:40:55 +0000 (02:40 +0000)]
add native a_crash primitive for arm
the .byte directive encodes a guaranteed-undefined instruction, the
same one Linux fills the kuser helper page with when it's disabled.
the udf mnemonic and and .insn directives are not supported by old
binutils versions, and larger-than-byte integer directives would
produce the wrong output on big-endian.
Szabolcs Nagy [Tue, 8 Sep 2015 19:31:58 +0000 (19:31 +0000)]
add new IP_BIND_ADDRESS_NO_PORT and IPPROTO_MPLS to netinet/in.h
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
Szabolcs Nagy [Tue, 8 Sep 2015 19:50:26 +0000 (19:50 +0000)]
update netinet/tcp.h for linux v4.2
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
Szabolcs Nagy [Fri, 26 Jun 2015 20:47:11 +0000 (20:47 +0000)]
add MS_LAZYTIME mount option to sys/mount.h
new in linux 4.0 commit
0ae45f63d4ef8d8eeec49c7d8b44a1775fff13e8,
used to update atime/mtime/ctime only in memory when possible.
Szabolcs Nagy [Fri, 26 Jun 2015 20:32:24 +0000 (20:32 +0000)]
add AF_MPLS (PF_MPLS) address family to socket.h
new in linux 4.0 commit
0189197f441602acdca3f97750d392a895b778fd.
Szabolcs Nagy [Fri, 26 Jun 2015 20:27:37 +0000 (20:27 +0000)]
add MSG_FASTOPEN sendmsg/sendto flag to socket.h
This was new in linux 3.5 in commit
cf60af03ca4e71134206809ea892e49b92a88896,
needed for tcp fastopen feature (sending data in TCP SYN packet).
Szabolcs Nagy [Wed, 18 Nov 2015 23:20:34 +0000 (23:20 +0000)]
clean powerpc syscall.h
remove ifdefs for powerpc64.
Szabolcs Nagy [Sun, 24 Jan 2016 00:20:43 +0000 (00:20 +0000)]
add missing powerpc specific PROT_SAO memory protection flag
this flag for strong access ordering was added in linux v2.6.27
commit
aba46c5027cb59d98052231b36efcbbde9c77a1d
Szabolcs Nagy [Sun, 24 Jan 2016 00:18:17 +0000 (00:18 +0000)]
fix powerpc MCL_* mlockall flags in bits/mman.h
the definitions didn't match the linux uapi headers.
Szabolcs Nagy [Sun, 24 Jan 2016 20:51:34 +0000 (20:51 +0000)]
fix aarch64 atomics to load/store 32bit only
a_ll/a_sc inline asm used 64bit register operands (%0) instead of 32bit
ones (%w0), this at least broke a_and_64 (which always cleared the top
32bit, leaking memory in malloc).
Rich Felker [Sat, 23 Jan 2016 19:03:40 +0000 (14:03 -0500)]
improve aarch64 atomics
aarch64 provides ll/sc variants with acquire/release memory order,
freeing us from the need to have full barriers both before and after
the ll/sc operation. previously they were not used because the a_cas
can fail without performing a_sc, in which case half of the barrier
would be omitted. instead, define a custom version of a_cas for
aarch64 which uses a_barrier explicitly when aborting the cas
operation. aside from cas, other operations built on top of ll/sc are
not affected since they never abort but rather loop until they
succeed.
a split ll/sc version of the pointer-sized a_cas_p is also introduced
using the same technique.
patch by Szabolcs Nagy.
Rich Felker [Fri, 22 Jan 2016 04:04:16 +0000 (04:04 +0000)]
add arch/abi info to dynamic linker's id/version output
Rich Felker [Fri, 22 Jan 2016 03:58:51 +0000 (03:58 +0000)]
remove arch/$(ARCH)/src from the build system
the files that used to come from extra src dirs under the arch dir
have all been removed or moved to appropriate places under the main
src tree.
Rich Felker [Fri, 22 Jan 2016 03:50:58 +0000 (03:50 +0000)]
remove sh port's __fpscr_values source file
commit
f3ddd173806fd5c60b3f034528ca24542aecc5b9, the dynamic linker
bootstrap overhaul, silently disabled the definition of __fpscr_values
in this file since libc.so's copy of __fpscr_values now comes from
crt_arch.h, the same place the public definition in the main program's
crt1.o ultimately comes from. remove this file which is no longer in
use.
Rich Felker [Fri, 22 Jan 2016 03:50:08 +0000 (03:50 +0000)]
move sh port's __shcall internal function from arch/sh/src to src tree
Rich Felker [Fri, 22 Jan 2016 03:46:00 +0000 (03:46 +0000)]
move sh __unmapself code from arch/sh/src to main src tree
Rich Felker [Fri, 22 Jan 2016 03:39:07 +0000 (03:39 +0000)]
move x32 sysinfo impl and syscall fixup code out of arch/x32/src
all such arch-specific translation units are being moved to
appropriate arch dirs under the main src tree.
Rich Felker [Fri, 22 Jan 2016 02:58:32 +0000 (02:58 +0000)]
overhaul powerpc atomics for new atomics framework
previously powerpc had a_cas defined in terms of its native ll/sc
style operations, but all other atomics were defined in terms of
a_cas. instead define a_ll and a_sc so the compiler can generate
optimized versions of all the atomic ops and perform better inlining
of a_cas.
extracting the result of the sc (stwcx.) instruction is rather awkward
because it's natively stored in a condition flag, which is not
representable in inline asm. but even with this limitation the new
code still seems significantly better.
Rich Felker [Fri, 22 Jan 2016 00:53:09 +0000 (00:53 +0000)]
clean up x86_64 (and x32) atomics for new atomics framework
this commit mostly makes consistent things like spacing, function
ordering in atomic_arch.h, argument names, use of volatile, etc.
a_ctz_l was also removed from x86_64 since atomic.h provides it
automatically using a_ctz_64.
Rich Felker [Fri, 22 Jan 2016 00:16:53 +0000 (00:16 +0000)]
clean up i386 atomics for new atomics framework
this commit mostly makes consistent things like spacing, function
ordering in atomic_arch.h, argument names, use of volatile, etc. the
fake 64-bit and/or atomics are also removed because the shared
atomic.h does a better job of implementing them; it avoids making two
atomic memory accesses when only one 32-bit half needs to be touched.
no major overhaul is needed or possible because x86 actually has
native versions of all the usual atomic operations, rather than using
ll/sc or needing cas loops.
Rich Felker [Fri, 22 Jan 2016 00:10:40 +0000 (00:10 +0000)]
overhaul mips atomics for new atomics framework
Rich Felker [Fri, 22 Jan 2016 00:02:21 +0000 (00:02 +0000)]
move arm-specific translation units out of arch/arm/src, to src/*/arm
this is possible with the new build system that allows src/*/$(ARCH)/*
files which do not shadow a file in the parent directory, and yields a
more logical organization. eventually it will be possible to remove
arch/*/src from the build system.
Rich Felker [Thu, 21 Jan 2016 23:30:30 +0000 (23:30 +0000)]
overhaul arm atomics for new atomics framework
switch to ll/sc model so that new atomic.h can provide optimized
versions of all the atomic primitives without needing an ll/sc loop
written in asm for each one.
all isa levels which use ldrex/strex now use the inline ll/sc model
even if the type of barrier to use is not known until runtime (v6).
the cas model is only used for arm v5 and earlier, and it has been
optimized to make the call via inline asm with custom constraints
rather than as a C function call.
Rich Felker [Thu, 21 Jan 2016 19:50:55 +0000 (19:50 +0000)]
overhaul aarch64 atomics for new atomics framework
Rich Felker [Thu, 21 Jan 2016 19:28:15 +0000 (19:28 +0000)]
overhaul sh atomics for new atomics framework, add j-core cas.l backend
sh needs runtime-selected atomic backends since there are a number of
supported models that use non-forwards-compatible (non-smp-compatible)
atomic mechanisms. previously, the code paths for this were highly
inefficient since they involved C function calls with multiple
branches in the callee and heavy spills in the caller. the new code
performs calls the runtime-selected asm fragment from inline asm with
extremely minimal clobbers, rather than using a function call.
for the sh4a case where the atomic mechanism is known and there is no
forward-compatibility issue, the movli.l and movco.l instructions are
provided as a_ll and a_sc, allowing the new shared atomic.h to
generate efficient inline versions of all the basic atomic operations
without needing a cas loop.
Rich Felker [Thu, 21 Jan 2016 19:08:54 +0000 (19:08 +0000)]
refactor internal atomic.h
rather than having each arch provide its own atomic.h, there is a new
shared atomic.h in src/internal which pulls arch-specific definitions
from arc/$(ARCH)/atomic_arch.h. the latter can be extremely minimal,
defining only a_cas or new ll/sc type primitives which the shared
atomic.h will use to construct everything else.
this commit avoids making heavy changes to the individual archs'
atomic implementations. definitions which are identical or
near-identical to what the new shared atomic.h would produce have been
removed, but otherwise the changes made are just hooking up the
arch-specific files to the new infrastructure. major changes to take
advantage of the new system will come in subsequent commits.
Rich Felker [Wed, 20 Jan 2016 19:43:37 +0000 (19:43 +0000)]
fix global visibility (vis.h) support for out-of-tree builds
commit
2f853dd6b9a95d5b13ee8f9df762125e0588df5d failed to change the
test for -include vis.h support to use $srcdir, so vis.h was always
disabled by configure for out-of-tree builds.
Khem Raj [Wed, 20 Jan 2016 18:14:15 +0000 (10:14 -0800)]
exclude vis.h when compiling assembly files
otherwise C declarations are included into preprocessed (.S) asm
source files, producing errors from the assembler.
Rich Felker [Wed, 20 Jan 2016 04:01:05 +0000 (04:01 +0000)]
simplify "make clean" and remove unneeded lib dir from tree
the lib dir is automatically created if needed by the out-of-tree
build logic, and now that all generated files are in obj and lib,
deleting them is much simpler. using "rm -rf" is also more thorough,
as it picks up object files that were left around from source files
that no longer exist or which are no longer to be used because an
arch-specific replacement file was added or removed.
Rich Felker [Wed, 20 Jan 2016 02:58:29 +0000 (02:58 +0000)]
deduplicate compiler invocation command line in makefile
also clean up duplication of CFLAGS passing to assembler.
Rich Felker [Wed, 20 Jan 2016 02:52:39 +0000 (02:52 +0000)]
remove outdated/incorrect comment about AS_CMD from makefile
Rich Felker [Wed, 20 Jan 2016 02:49:32 +0000 (02:49 +0000)]
remove support for subarch .sub files from the makefile
as of commit
af21a82ccc8687aa16e85def7db95efeae4cf72e, .sub files are
no longer in use. removing the makefile machinery to handle them not
only cleans up and simplifies the makefile, but also significantly
reduces make's startup time.
Rich Felker [Wed, 20 Jan 2016 02:31:06 +0000 (02:31 +0000)]
fix build regression for arm pre-v7 from out-of-tree build patch
commit
2f853dd6b9a95d5b13ee8f9df762125e0588df5d failed to replicate
the old makefile logic that caused arch/arm/src/arm/atomics.s to be
built. since this was the only .s file under arch/*/src, rather than
trying to reproduce the old logic, I'm just moving it up a level and
adjusting the glob pattern in the makefile to catch it. eventually
arch/*/src will probably be removed in favor of moving all these files
to appropriate src/*/$(ARCH) locations.
Rich Felker [Wed, 20 Jan 2016 02:07:59 +0000 (02:07 +0000)]
switch arm, sh, and mips fenv asm from .sub system to .S files
Rich Felker [Wed, 20 Jan 2016 01:44:06 +0000 (01:44 +0000)]
switch sh and mips setjmp asm from .sub system to .S files
Rich Felker [Wed, 20 Jan 2016 01:16:09 +0000 (01:16 +0000)]
fix dynamic linker path file selection for arm vs armhf
the __SOFTFP__ macro which was wrongly being used does not reflect the
ABI (arm vs armhf) but just the availability of floating point
instructions/registers, so -mfloat-abi=softfp was wrongly being
treated as armhf. __ARM_PCS_VFP is the correct predefined macro to
check for the armhf EABI variant. this macro usage was corrected for
the build process in commit
4918c2bb206bfaaf5a1f7d3448c2f63d5e2b7d56
but reloc.h was apparently overlooked at the time.
Rich Felker [Wed, 20 Jan 2016 01:09:57 +0000 (01:09 +0000)]
replace armhf math asm source files with inline asm
this makes it possible to inline them with LTO, and is the simplest
approach to eliminating the use of .sub files.
this also makes VFP sqrt available for use with the standard EABI
(plain arm rather than armhf subarch) when libc is built with
-mfloat-abi=softfp. the same could have been done for fabs, but when
the argument and return value are in integer registers, moving to VFP
registers and back is almost certainly more costly than a simple
integer operation.
Rich Felker [Wed, 20 Jan 2016 00:35:05 +0000 (00:35 +0000)]
adapt build of arm memcpy asm not to use .sub files
this depends on commit
9f5eb77992b42d484d69e879d24ef86466f20f21, which
made it possible to use a .c file for arch-specific replacements, and on
commit
2f853dd6b9a95d5b13ee8f9df762125e0588df5d, the out-of-tree build
support, which made it so that src/*/$(ARCH)/* 'replacement' files get
used even if they don't match the base name of a .c file in the parent
directory.
Rich Felker [Wed, 20 Jan 2016 00:08:52 +0000 (19:08 -0500)]
eliminate separate static/shared CFLAGS vars in makefile
this allows the rules for .o and .lo files to be identical, with -fPIC
and -DSHARED added for .lo files via target-specific variable append.
this is arguably cleaner now and will allow more cleanup and removal
of redundant rule bodies after other prerequisite changes are made.
Rich Felker [Tue, 19 Jan 2016 23:19:01 +0000 (18:19 -0500)]
add support for arch-provided replacement files as .c or .S
previously, replacement files provided in $(ARCH) dirs under src/ had
to be .s files. in order to replace a file with C source, an empty .s
file was needed there to suppress the original file, and a separate .c
file was needed in arch/$(ARCH)/src/.
support for .S is new and is aimed at short-term use eliminating .sub
files. asm source files are still expected not to make any heavy
preprocessor use, just simple conditionals on subarch. eventually most
affected files may be replaced with C source files with minimal inline
asm instead of asm source files.
Kylie McClain [Wed, 30 Dec 2015 22:24:02 +0000 (17:24 -0500)]
netinet/tcp: Add TCPOPT, TCPOLEN constants
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.
Ron Yorston [Fri, 15 Jan 2016 09:39:44 +0000 (09:39 +0000)]
fix if_nametoindex return value when socket open fails
The return value of if_nametoindex is unsigned; it should return 0
on error.
Petr Hosek [Wed, 18 Nov 2015 20:07:32 +0000 (12:07 -0800)]
support out-of-tree build
this change adds support for building musl outside of the source
tree. the implementation is similar to autotools where running
configure in a different directory creates config.mak in the current
working directory and symlinks the makefile, which contains the
logic for creating all necessary directories and resolving paths
relative to the source directory.
to support both in-tree and out-of-tree builds with implicit make
rules, all object files are now placed into a separate directory.
Timo Teräs [Tue, 5 Jan 2016 14:58:40 +0000 (16:58 +0200)]
add missing protocols to protoent lookup functions
Rich Felker [Tue, 29 Dec 2015 18:01:29 +0000 (13:01 -0500)]
adjust mips crt_arch entry point asm to avoid assembler bugs
apparently the .gpword directive does not work reliably with local
text labels; values produced were offset by 64k from the correct
value, resulting in incorrect computation of the got pointer at
runtime. instead, use an external label so that the assembler does not
munge the relocation; the linker will then get it right.
commit
6fef8cafbd0f6f185897bc87feb1ff66e2e204e1 exposed this issue by
removing the old, non-PIE-compatible handwritten crt1.s, which was not
affected. presumably mips PIE executables (using Scrt1.o produced from
crt_arch.h) were already affected at the time.
Rich Felker [Tue, 29 Dec 2015 17:46:15 +0000 (12:46 -0500)]
adjust i386 max_align_t definition to work around some broken compilers
at least gcc 4.7 claims c++11 support but does not accept the alignas
keyword, causing breakage when stddef.h is included in c++11 mode.
instead, prefer using __attribute__((__aligned__)) on any compiler
with GNU extensions, and only use the alignas keyword as a fallback
for other C++ compilers.
C code should not be affected by this patch.
Rich Felker [Sun, 20 Dec 2015 05:32:46 +0000 (00:32 -0500)]
fix overly pessimistic realloc strategy in getdelim
previously, getdelim was allocating twice the space needed every time
it expanded its buffer to implement exponential buffer growth (in
order to avoid quadratic run time). however, this doubling was
performed even when the final buffer length needed was already known,
which is the common case that occurs whenever the delimiter is in the
FILE's buffer.
this patch makes two changes to remedy the situation:
1. over-allocation is no longer performed if the delimiter has already
been found when realloc is needed.
2. growth factor is reduced from 2x to 1.5x to reduce the relative
excess allocation in cases where the delimiter is not initially in the
buffer, including unbuffered streams.
in theory these changes could lead to quadratic time if the same
buffer is reused to process a sequence of lines successively
increasing in length, but once this length exceeds the stdio buffer
size, the delimiter will not be found in the buffer right away and
exponential growth will still kick in.
Rich Felker [Sun, 20 Dec 2015 04:43:31 +0000 (23:43 -0500)]
avoid updating caller's size when getdelim fails to realloc
getdelim was updating *n, the caller's stored buffer size, before
calling realloc. if getdelim then failed due to realloc failure, the
caller would see in *n a value larger than the actual size of the
allocated block, and use of that value is unsafe. in particular,
passing it again to getdelim is unsafe.
now, temporary storage is used for the desired new size, and *n is not
written until realloc succeeds.
Rich Felker [Wed, 16 Dec 2015 04:20:36 +0000 (23:20 -0500)]
fix crash when signal number 0 is passed to sigaction
this error case was overlooked in the old range checking logic. new
check is moved out of __libc_sigaction to the public wrapper in order
to unify the error path and reduce code size.
Rich Felker [Wed, 16 Dec 2015 04:18:38 +0000 (23:18 -0500)]
remove visibility suppression by SHARED macro in mips and x32 arch files
commit
8a8fdf6398b85c99dffb237e47fa577e2ddc9e77 was intended to remove
all such usage, but these arch-specific files were overlooked, leading
to inconsistent declarations and definitions.
Szabolcs Nagy [Sat, 5 Dec 2015 20:53:59 +0000 (21:53 +0100)]
fix tsearch, tfind, tdelete to handle null pointer input
POSIX specifies the behaviour for null rootp input, but it
was not implemented correctly.
Szabolcs Nagy [Sat, 5 Dec 2015 20:06:02 +0000 (21:06 +0100)]
tsearch code cleanup
changed the insertion method to simplify the recursion logic and
reduce code size a bit.
Szabolcs Nagy [Sat, 5 Dec 2015 20:04:18 +0000 (21:04 +0100)]
fix tsearch to avoid crash on oom
malloc failure was not properly propagated in the insertion method
which led to null pointer dereference.
Szabolcs Nagy [Sat, 5 Dec 2015 20:02:34 +0000 (21:02 +0100)]
fix tdelete to properly balance the tree
the tsearch data structure is an avl tree, but it did not implement
the deletion operation correctly so the tree could become unbalanced.
reported by Ed Schouten.
Jo-Philipp Wich [Thu, 19 Nov 2015 20:43:10 +0000 (21:43 +0100)]
properly handle point-to-point interfaces in getifaddrs()
With point-to-point interfaces, the IFA_ADDRESS netlink attribute
contains the peer address while an extra attribute IFA_LOCAL carries
the actual local interface address.
Both the glibc and uclibc implementations of getifaddrs() handle this
case by moving the ifa_addr contents to the broadcast/remote address
union and overwriting ifa_addr upon receipt of an IFA_LOCAL attribute.
This patch adds the same special treatment logic of IFA_LOCAL to
musl's implementation of getifaddrs() in order to align its behaviour
with that of uclibc and glibc.
Signed-off-by: Jo-Philipp Wich <jow@openwrt.org>
Szabolcs Nagy [Thu, 26 Nov 2015 18:59:46 +0000 (19:59 +0100)]
ldso: fix the dtv update logic in __tls_get_new
if two or more threads accessed tls in a dso that was loaded after
the threads were created, then __tls_get_new could do out-of-bound
memory access (leading to segfault).
accidentally byte count was used instead of element count when
the new dtv pointer was computed. (dso->new_dtv is (void**).)
it is rare that the same dso provides dtv for several threads,
the crash was not observed in practice, but possible to trigger.
Rich Felker [Sat, 21 Nov 2015 21:23:30 +0000 (21:23 +0000)]
math: explicitly promote expressions to excess-precision types
a conforming compiler for an arch with excess precision floating point
(FLT_EVAL_METHOD!=0; presently i386 is the only such arch supported)
computes all intermediate results in the types float_t and double_t
rather than the nominal type of the expression. some incorrect
compilers, however, only keep excess precision in registers, and
convert down to the nominal type when spilling intermediate results to
memory, yielding unpredictable results that depend on the compiler's
choices of what/when to spill. in particular, this happens on old gcc
versions with -ffloat-store, which we need in order to work around
bugs where the compiler wrongly keeps explicitly-dropped excess
precision.
by explicitly converting to double_t where expressions are expected be
be evaluated in double_t precision, we can avoid depending on the
compiler to get types correct when spilling; the nominal and
intermediate precision now match. this commit should not change the
code generated by correct compilers, or by old ones on non-i386 archs
where double_t is defined as double.
this fixes a serious bug in argument reduction observed on i386 with
gcc 4.2: for values of x outside the unit circle, sin(x) was producing
results outside the interval [-1,1]. changes made in commit
0ce946cf808274c2d6e5419b139e130c8ad4bd30 were likely responsible for
breaking compatibility with this and other old gcc versions.
patch by Szabolcs Nagy.
Rich Felker [Fri, 20 Nov 2015 01:28:08 +0000 (20:28 -0500)]
remove undef weak refs to init/fini array symbols in libc.so
commit
ad1cd43a86645ba2d4f7c8747240452a349d6bc1 eliminated
preprocessor-level omission of references to the init/fini array
symbols from object files going into libc.so. the references are weak,
and the intent was that the linker would resolve them to zero in
libc.so, but instead it leaves undefined references that could be
satisfied at runtime. normally these references would be harmless,
since the code using them does not even get executed, but some older
binutils versions produce a linking error: when linking a program
against libc.so, ld first tries to use the hidden init/fini array
symbols produced by the linker script to satisfy the references in
libc.so, then produces an error because the definitions are hidden.
ideally ld would have already provided definitions of these symbols
when linking libc.so, but the linker script for -shared omits them.
to avoid this situation, the dynamic linker now provides its own dummy
definitions of the init/fini array symbols for libc.so. since they are
hidden, everything binds at ld time and no references remain in the
dynamic symbol table. with modern binutils and --gc-sections, both
the dummy empty array objects and the code referencing them get
dropped at link time, anyway.
the _init and _fini symbols are also switched back to using weak
definitions rather than weak references since the latter behave
somewhat problematically in general, and the weak definition approach
was known to work well.
Rich Felker [Thu, 19 Nov 2015 00:00:44 +0000 (19:00 -0500)]
fix build regression from removal of #ifdef SHARED
Rich Felker [Mon, 16 Nov 2015 02:28:41 +0000 (21:28 -0500)]
use private maps even for read-only segments of FDPIC libraries
the nommu kernel shares memory when it can anyway for private
read-only maps, but semantically the map should be private. this can
make a difference when debugging breakpoints are to be used, in which
case the kernel may need to ensure that the mapping is not shared.
the new behavior matches how the kernel FDPIC loader maps the main
program and/or program interpreter (dynamic linker) binary.
Rich Felker [Thu, 12 Nov 2015 21:13:52 +0000 (16:13 -0500)]
remove use of SHARED macro in dynamic linker version reporting
also fix visibility of the glue function used.
Rich Felker [Thu, 12 Nov 2015 20:50:26 +0000 (15:50 -0500)]
unify static and dynamic linked implementations of thread-local storage
this both allows removal of some of the main remaining uses of the
SHARED macro and clears one obstacle to static-linked dlopen support,
which may be added at some point in the future.
specialized single-TLS-module versions of __copy_tls and __reset_tls
are removed and replaced with code adapted from their dynamic-linked
versions, capable of operating on a whole chain of TLS modules, and
use of the dynamic linker's DSO chain (which contains large struct dso
objects) by these functions is replaced with a new chain of struct
tls_module objects containing only the information needed for
implementing TLS. this may also yield some performance benefit
initializing TLS for a new thread when a large number of modules
without TLS have been loaded, since since there is no need to walk
structures for modules without TLS.
Rich Felker [Thu, 12 Nov 2015 03:08:23 +0000 (22:08 -0500)]
unify static and dynamic libc init/fini code paths
use weak definitions that the dynamic linker can override instead of
preprocessor conditionals on SHARED so that the same libc start and
exit code can be used for both static and dynamic linking.
Rich Felker [Thu, 12 Nov 2015 00:43:56 +0000 (19:43 -0500)]
eliminate use of SHARED macro in __tls_get_addr
this was only a tiny optimization, and static-linked binaries should
not be calling __tls_get_addr anyway since the linker is supposed to
perform relaxation, resulting in use of the local-exec TLS model.
Rich Felker [Thu, 12 Nov 2015 00:29:45 +0000 (19:29 -0500)]
eliminate use of SHARED macro to suppress visibility attributes
this is the first and simplest stage of removal of the SHARED macro,
which will eventually allow libc.a and libc.so to be produced from the
same object files.
the original motivation for these #ifdefs which are now being removed
was to allow building a static-only libc using a compiler that does
not support visibility. however, SHARED was the wrong condition to
test for this anyway; various assembly-language sources refer to
hidden symbols and declare them with the .hidden directive, making it
wrong to define the referenced symbols as non-hidden. if there is a
need in the future to build libc using compilers that lack visibility,
support could be moved to the build system or perhaps the __PIC__
macro could be checked instead of SHARED.
Rich Felker [Wed, 11 Nov 2015 23:27:23 +0000 (18:27 -0500)]
use correct nofpu versions of setjmp/longjmp used on sh-nofpu-fdpic
when adding the fdpic subarchs, the need for these sub files was
overlooked. thus setjmp and longjmp performed illegal instructions.
Rich Felker [Wed, 11 Nov 2015 22:34:17 +0000 (17:34 -0500)]
fix dynamic loader library mapping for nommu systems
on linux/nommu, non-writable private mappings of files may actually
use memory shared with other processes or the fs cache. the old nommu
loader code (used when mmap with MAP_FIXED fails) simply wrote over
top of the original file mapping, possibly clobbering this shared
memory. no such breakage was observed in practice, but it should have
been possible.
the new code starts by mapping anonymous writable memory on archs that
might support nommu, then maps load segments over top of it, falling
back to read if MAP_FIXED fails. we use an anonymous map rather than a
writable file map to avoid reading more data from disk than needed.
since pages cannot be loaded lazily on fault, in case of large
data/bss, mapping the full file may read a lot of data that will
subsequently be thrown away when processing additional LOAD segments.
as a result, we cannot skip the first LOAD segment when operating in
this mode.
these changes affect only non-FDPIC nommu support.
Rich Felker [Wed, 11 Nov 2015 04:07:17 +0000 (23:07 -0500)]
fix return value of nl_langinfo for invalid item arguments
it was wrongly returning a null pointer instead of an empty string.
Rich Felker [Tue, 10 Nov 2015 05:01:55 +0000 (00:01 -0500)]
explicitly assemble all arm asm sources as UAL
these files are all accepted as legacy arm syntax when producing arm
code, but legacy syntax cannot be used for producing thumb2 with
access to the full ISA. even after switching to UAL, some asm source
files contain instructions which are not valid in thumb mode, so these
will need to be addressed separately.
Rich Felker [Tue, 10 Nov 2015 03:36:38 +0000 (22:36 -0500)]
remove non-working pre-armv4t support from arm asm
the idea of the three-instruction sequence being removed was to be
able to return to thumb code when used on armv4t+ from a thumb caller,
but also to be able to run on armv4 without the bx instruction
available (in which case the low bit of lr would always be 0).
however, without compiler support for generating such a sequence from
C code, which does not exist and which there is unlikely to be
interest in implementing, there is little point in having it in the
asm, and it would likely be easier to add pre-armv4t support via
enhanced linker handling of R_ARM_V4BX than at the compiler level.
removing this code simplifies adding support for building libc in
thumb2-only form (for cortex-m).
Rich Felker [Tue, 10 Nov 2015 02:14:07 +0000 (21:14 -0500)]
use vfp mnemonics rather than hard-coded opcodes in arm setjmp/longjmp
the code to save/restore vfp registers needs to build even when the
configured target does not have fpu; this is because code using vfp
fpu (but with the standard soft-float EABI) may call a libc built for
a soft-float only, and the EABI considers these registers call-saved
when they exist. thus, extra directives are used to force the
assembler to allow vfp instructions and to avoid marking the resulting
object files as requiring vfp.
moving away from using hard-coded opcode words is necessary in order
to eventually support producing thumb2-only output for cortex-m.
conditional execution of these instructions based on hwcap flags was
already implemented. when building for arm (non-thumb) output, the
only currently-supported configuration, this commit does not change
the code emitted.
Rich Felker [Sun, 8 Nov 2015 01:23:49 +0000 (20:23 -0500)]
work around toolchains with broken visibility in libgcc/libpcc
Szabolcs Nagy [Thu, 5 Nov 2015 23:13:11 +0000 (18:13 -0500)]
use vfp mnemonics instead of p10 coprocessor ones in armhf fenv asm
mrc/mcr p10 coprocessor mnemonics are deprecated by some
toolchains.
Rich Felker [Mon, 19 Oct 2015 00:17:43 +0000 (20:17 -0400)]
convert arm memcpy asm to UAL, remove .word hacks
contrary to commit
9367fe926196f407705bb07cd29c6e40eb1774dd, all
relevant gas versions actually do support .syntax unified.
Rich Felker [Thu, 5 Nov 2015 02:41:29 +0000 (21:41 -0500)]
remove external linkage from __simple_malloc definition
this function is used only as a weak definition for malloc, for static
linking in programs which do not call realloc or free. since it had
external linkage and was thereby exported in libc.so's dynamic symbol
table, --gc-sections was unable to drop it. this was merely an
oversight; there's no reason for it to be external, so make it static.
Rich Felker [Thu, 5 Nov 2015 02:40:36 +0000 (21:40 -0500)]
have configure check/add --gc-sections linker option
this allowing the linker to drop certain weak definitions that are
only used as dummies for static linking. they could be eliminated for
shared library builds using the preprocessor instead, but we are
trying to transition to using the same object files for shared and
static libc, so a link-time solution is preferable.
Rich Felker [Thu, 5 Nov 2015 02:39:13 +0000 (21:39 -0500)]
have configure check/add linker options to reduce size lost to padding
based on patch by Denys Vlasenko. sorting sections and common data
symbols by alignment acts as an approximation for optimal packing,
which the linker does not actually support.
Rich Felker [Wed, 4 Nov 2015 18:24:11 +0000 (13:24 -0500)]
have configure check/add -ffunction-sections and -fdata-sections
based on patch by Denys Vlasenko. the original intent for using these
options was to enable linking optimizations. these are immediately
available for static linking applications to libc.a, and will also be
used for linking libc.so in a subsequent commit.
in addition to the original motives, this change works around a whole
class of toolchain bugs where the compiler generates relative address
expressions using a weak symbol and the assembler "optimizes out" the
relocation which should result by using the weak definition. (see gas
pr 18561 and gcc pr 66609, 68178, etc. for examples.) by having
different functions and data objects in their own sections, all
relative address expressions are cross-section and thus cannot be
resolved to constants until link time. this allows us to retain
support for affected compiler/assembler versions without invasive
and fragile source-level workarounds.
Rich Felker [Tue, 3 Nov 2015 02:44:57 +0000 (21:44 -0500)]
fix mismatched parens in CMPLX def for annex-g-conforming compilers
this conditional path was never tested because there are no compilers
that conform to annex g (none with _Imaginary_I).
Rich Felker [Mon, 2 Nov 2015 23:11:36 +0000 (18:11 -0500)]
generalize sh entry point asm not to assume call dests fit in 12 bits
this assumption is borderline-unsafe to begin with, and fails badly
with -ffunction-sections since the linker can move the callee
arbitrarily far away when it lies in a different section.