Commit Graph

154 Commits

Author SHA1 Message Date
Rich Felker
dde325d7b3 fix struct stat size/padding on microblaze 2012-10-19 18:52:14 -04:00
Rich Felker
25011215be inline syscalls for microblaze 2012-10-18 22:13:36 -04:00
Rich Felker
64251d8bbd better support for reverse-endian variants of arm/mips/microblaze
these macros are supported by more compilers
2012-10-18 21:50:55 -04:00
Rich Felker
f321de9e0a floating point environment/exceptions support for mips 2012-10-18 20:19:53 -04:00
Rich Felker
21284ec75d microblaze TLS relocation support, completely untested 2012-10-15 21:01:48 -04:00
Rich Felker
9ec4283b28 add support for TLS variant I, presently needed for arm and mips
despite documentation that makes it sound a lot different, the only
ABI-constraint difference between TLS variants II and I seems to be
that variant II stores the initial TLS segment immediately below the
thread pointer (i.e. the thread pointer points to the end of it) and
variant I stores the initial TLS segment above the thread pointer,
requiring the thread descriptor to be stored below. the actual value
stored in the thread pointer register also tends to have per-arch
random offsets applied to it for silly micro-optimization purposes.

with these changes applied, TLS should be basically working on all
supported archs except microblaze. I'm still working on getting the
necessary information and a working toolchain that can build TLS
binaries for microblaze, but in theory, static-linked programs with
TLS and dynamic-linked programs where only the main executable uses
TLS should already work on microblaze.

alignment constraints have not yet been heavily tested, so it's
possible that this code does not always align TLS segments correctly
on archs that need TLS variant I.
2012-10-15 18:51:53 -04:00
Rich Felker
185a977074 ensure pointer decay in inline-asm arg for i386 syscall6
this is actually a rather subtle issue: do arrays decay to pointers
when used as inline asm args? gcc says yes, but currently pcc says no.
hopefully this discrepency in pcc will be fixed, but since the
behavior is not clearly defined anywhere I can find, I'm using an
explicit operation to cause the decay to occur.
2012-10-13 23:46:51 -04:00
Rich Felker
12e9b4faf6 i386 vsyscall support (vdso-provided sysenter/syscall instruction based)
this doubles the performance of the fastest syscalls on the atom I
tested it on; improvement is reportedly much more dramatic on
worst-case cpus. cannot be used for cancellable syscalls.
2012-10-11 22:47:07 -04:00
Rich Felker
99a2af6f45 fix incorrect TLS reloc macro names in x86_64 reloc.h 2012-10-05 01:00:40 -04:00
Rich Felker
9c74856af7 dynamic-linked TLS support for everything but dlopen'd libs
currently, only i386 is tested. x86_64 and arm should probably work.
the necessary relocation types for mips and microblaze have not been
added because I don't understand how they're supposed to work, and I'm
not even sure if it's defined yet on microblaze. I may be able to
reverse engineer the requirements out of gcc/binutils output.
2012-10-04 22:48:33 -04:00
Rich Felker
8c0a3d9e5c microblaze port
based on initial work by rdp, with heavy modifications. some features
including threads are untested because qemu app-level emulation seems
to be broken and I do not have a proper system image for testing.
2012-09-29 01:05:31 -04:00
Rich Felker
cccc13221d fix IPC_64 in msgctl too 2012-09-22 08:04:17 -04:00
Rich Felker
fce46bf980 fix broken semctl on systems that don't use IPC_64 flag
not tested on mips and arm; they may still be broken. x86_64 should be
ok now.
2012-09-22 08:02:42 -04:00
Rich Felker
6d05d86297 add O_EXEC open mode
the linux O_PATH mode provides the necessary semantics for both the
O_SEARCH and O_EXEC modes defined and required by POSIX 2008.
2012-09-15 23:45:41 -04:00
Rich Felker
075fdb909b fix syscall asm constraints for arm too
no problems were detected so far, but the constraints seem to have
been invalid just like the mips ones.
2012-09-15 03:19:41 -04:00
Rich Felker
4221f154ff fix buggy constraints in mips inline syscall asm
if same register is used for input/output, the compiler must be told.
otherwise is generates random junk code that clobbers the result. in
pure syscall-wrapper functions, nothing went wrong, but in more
complex functions where register allocation is non-trivial, things
broke badly.
2012-09-15 02:22:10 -04:00
Rich Felker
b238b37a0f add O_PATH/O_SEARCH support to fcntl.h
I'm not 100% sure that Linux's O_PATH meets the POSIX requirements for
O_SEARCH, but it seems very close if not perfect. and old kernels
ignore it, so O_SEARCH will still work as desired as long as the
caller has read permissions to the directory.
2012-09-13 20:56:25 -04:00
Rich Felker
cfc09b1ecf improve mips syscall asm constraints to use immediates, if possible
by using the "ir" constraint (immediate or register) and the carefully
constructed instruction addu $2,$0,%2 which can take either an
immediate or a register for %2, the new inline asm admits maximal
optimization with no register spillage to the stack when the compiler
successfully performs constant propagration, but still works by
allocating a register when the syscall number cannot be recognized as
a constant. in the case of syscalls with 0-3 arguments it barely
matters, but for 4-argument syscalls, using an immediate for the
syscall number avoids creating a stack frame for the syscall wrapper
function.
2012-09-11 02:23:47 -04:00
Rich Felker
b94067eeae eliminate assumption that mips syscall restart preserves r25
all past and current kernel versions have done so, but there seems to
be no reason it's necessary and the sentiment from everyone I've asked
has been that we should not rely on it. instead, use r7 (an argument
register) which will necessarily be preserved upon syscall restart.
however this only works for 0-3 argument syscalls, and we have to
resort to the function call for 4-argument syscalls.
2012-09-10 22:43:22 -04:00
Rich Felker
5e3c243d8d inline syscall support for arm
most pure-syscall-wrapper functions compile to the smallest/simplest
code possible (save r7 ; load syscall # ; svc 0 ; restore r7 ; tail
call to __syscall_ret).
2012-09-09 01:29:19 -04:00
Rich Felker
328810d325 inline syscall support for mips
this drastically reduces the size of some functions which are purely
syscall wrappers.

disabled for clang due to known bugs satisfying register constraints.
2012-09-09 01:01:19 -04:00
Rich Felker
208eb584ef syscall organization overhaul
now public syscall.h only exposes __NR_* and SYS_* constants and the
variadic syscall function. no macros or inline functions, no
__syscall_ret or other internal details, no 16-/32-bit legacy syscall
renaming, etc. this logic has all been moved to src/internal/syscall.h
with the arch-specific parts in arch/$(ARCH)/syscall_arch.h, and the
amount of arch-specific stuff has been reduced to a minimum.

changes still need to be reviewed/double-checked. minimal testing on
i386 and mips has already been performed.
2012-09-08 22:43:14 -04:00
Rich Felker
6cf8bfdb64 add acct, accept4, setns, and dup3 syscalls (linux extensions)
based on patch by Justin Cormack
2012-09-08 20:22:08 -04:00
Rich Felker
9f65796c35 add clang-compatible thread-pointer code for mips
clang does not presently support the "v" constraint we want to use to
get the result from $3, and trying to use register...__asm__("$3") to
do the same invokes serious compiler bugs. so for now, i'm working
around the issue with an extra temp register and putting $3 in the
clobber list instead of using it as output. when the bugs in clang are
fixed, this issue should be revisited to generate smaller/faster code
like what gcc gets.
2012-09-07 12:18:14 -04:00
Rich Felker
fb247fafa0 avoid "inline" in public headers for strict c89 compatibility
while musl itself requires a c99 compiler, some applications insist on
being compiled with c89 compilers, and use of "inline" in the headers
was breaking them. much of this had been avoided already by just
skipping the inline keyword in pre-c99 compilers or modes, but this
new unified solution is cleaner and may/should result in better code
generation in the default gcc configuration.
2012-09-02 12:46:06 -04:00
Rich Felker
036eaa24cf avoid need for -march=mips2 to compile mips atomic.h asm
linux guarantees ll/sc are always available. on mips1, they will be
emulated by the kernel. thus they are part of the linux mips1 abi and
safe to use.
2012-08-11 19:51:21 -04:00
Rich Felker
e3ebe7db5d use int instead of long for ptrdiff_t on all 32-bit archs
this is needed to match the underlying "ABI" standards. it's not
really an ABI issue since the binary representations are the same, but
having the wrong type can lead to errors when the type arising from a
difference-of-pointers expression does not match the defined type of
ptrdiff_t. most of the problems affect C++, not C.
2012-08-10 15:13:26 -04:00
Rich Felker
c5875ad34b fix incorrect ptrdiff_t type on mips 2012-08-10 14:59:20 -04:00
Rich Felker
83b42d94bd add defines for number of sigset_t bytes syscalls expect
yet another gratuitous mips incompatibility...
2012-08-09 21:35:19 -04:00
Rich Felker
ae0b9da48c further fixes for mips ioctl.h header
untested; hopefully it's right now
2012-08-07 19:59:28 -04:00
Rich Felker
ff02f94e2d fix another mips gratuitous-incompatibility bug: ioctl numbers 2012-08-07 19:19:21 -04:00
Rich Felker
7fee5f9606 fix socket.h on mips
why does mips have to be gratuitously incompatible in every possible
imaginable way?
2012-08-05 14:23:40 -04:00
Rich Felker
fa91df41e8 more stuff lost committing mips dynamic linker 2012-08-05 13:48:42 -04:00
Rich Felker
babf820180 mips dynamic linker support
not heavily tested, but the basics are working. the basic concept is
that the dynamic linker entry point code invokes a pure-PIC (no global
accesses) C function in reloc.h to perform the early GOT relocations
needed to make the dynamic linker itself functional, then invokes
__dynlink like on other archs. since mips uses some ugly arch-specific
hacks to optimize relocating the GOT (rather than just using the
normal DT_REL[A] tables like on other archs), the dynamic linker has
been modified slightly to support calling arch-specific relocation
code in reloc.h.

most of the actual mips-specific behavior was developed by reading the
output of readelf on libc.so and simple executable files. i could not
find good reference information on which relocation types need to be
supported or their semantics, so it's possible that some legitimate
usage cases will not work yet.
2012-08-05 12:50:26 -04:00
Rich Felker
dc046f55bb add floating point register saving/restoring to mips setjmp/longjmp
also fix the alignment of jmp_buf to meet the abi. linux always
emulates fpu on mips if it's not present, so enabling this code
unconditionally is "safe" but may be slow. in the long term it may be
preferable to find a way to disable it on soft float builds.
2012-07-22 18:55:01 -04:00
Rich Felker
48d20136b0 fix broken mips a_fetch_add
sc was overwriting the result
2012-07-12 23:18:03 -04:00
Rich Felker
e1e4d6b269 mipsel (little endian) support
the fields in the mcontext_t are long long (for no good reason) even
on 32-bit mips, so the offset of the instruction pointer (as a word)
varies depending on endianness.
2012-07-12 21:49:30 -04:00
Rich Felker
96107564e2 workaround another sendmsg kernel bug on 64-bit machines
the kernel wrongly expects the cmsg length field to be size_t instead
of socklen_t. in order to work around the issue, we have to impose a
length limit and copy to a local buffer. the length limit should be
more than sufficient for any real-world use; these headers are only
used for passing file descriptors and permissions between processes
over unix sockets.
2012-07-12 21:37:54 -04:00
Rich Felker
90e123f4a8 fix redef of sigprocmask constants on mips
this fix is easier than trying to reorder the header stuff
2012-07-12 16:54:43 -04:00
Rich Felker
ba8a96b068 more mips bits-header fixes
signal handling was very broken because of this
2012-07-12 14:21:41 -04:00
Rich Felker
db11e96493 fix mips syscalls with long long args
like arm, mips requires 64-bit arguments to be "aligned" on an even
register boundary.
2012-07-12 13:48:56 -04:00
Rich Felker
5fac93db37 fix mips mcontext_t structure size
otherwise offs in ucontext_t will be wrong, and break code that
inspects or modifies the signal makes (including cancellation code).
2012-07-12 00:14:40 -04:00
Rich Felker
2b3cc04a8d fix MAP_ANONYMOUS value for mips, remove cruft copied from i386 2012-07-11 22:29:57 -04:00
Rich Felker
6315004f61 initial version of mips (o32) port, based on work by Richard Pennington (rdp)
basically, this version of the code was obtained by starting with
rdp's work from his ellcc source tree, adapting it to musl's build
system and coding style, auditing the bits headers for discrepencies
with kernel definitions or glibc/LSB ABI or large file issues, fixing
up incompatibility with the old binutils from aboriginal linux, and
adding some new special cases to deal with the oddities of sigaction
and pipe syscall interfaces on mips.

at present, minimal test programs work, but some interfaces are broken
or missing. threaded programs probably will not link.
2012-07-11 04:22:13 -04:00
Rich Felker
bd1cf09c37 support -mfpmath=387 on x86_64
apparently somebody wants this for something... and it doesn't hurt.
2012-07-10 01:18:40 -04:00
Rich Felker
59c4ead16a fix wrong value of FLT_EVAL_METHOD for x86_64 2012-07-10 00:59:58 -04:00
Rich Felker
8bbc3be4b4 make arm syscalls (still non-inline) more efficient
no need to pass zero for unused arguments; just omit them.
2012-07-08 21:32:45 -04:00
Rich Felker
a3bdcd9376 remove little-endian assumption from arm atomic.h
this hidden endian dependency had left big endian arm badly broken.
2012-07-08 00:05:08 -04:00
Rich Felker
d6c0efe106 jmp_buf overhaul fixing several issues
on arm, the location of the saved-signal-mask flag and mask were off
by one between sigsetjmp and siglongjmp, causing incorrect behavior
restoring the signal mask. this is because the siglongjmp code assumed
an extra slot was in the non-sig jmp_buf for the flag, but arm did not
have this. now, the extra slot is removed for all archs since it was
useless.

also, arm eabi requires jmp_buf to have 8-byte alignment. we achieve
that using long long as the type rather than with non-portable gcc
attribute tags.
2012-07-03 20:07:33 -04:00
Rich Felker
213db3e3fa update syscall defs to latest kernel ones
patch submitted by Kristian L. <email@thexception.net>
2012-06-23 21:16:44 -04:00