STREAMS are utterly useless as far as I can tell, but some software
was apparently broken by the presence of stropts.h but lack of macros
it's supposed to define...
Rich Felker [Thu, 30 Jun 2011 20:31:43 +0000 (16:31 -0400)]
catch invalid ld80 bit patterns and treat them as nan
this should not be necessary - the invalid bit patterns cannot be
created except through type punning. however, some broken gnu software
is passing them to printf and triggering dangerous stack-smashing, so
let's catch them anyway...
Rich Felker [Thu, 30 Jun 2011 15:42:33 +0000 (11:42 -0400)]
implement the nonstandard GNU function fpurge
this is a really ugly and backwards function, but its presence will
prevent lots of broken gnulib software from trying to define its own
version of fpurge and thereby failing to build or worse.
Rich Felker [Wed, 29 Jun 2011 04:42:42 +0000 (00:42 -0400)]
work around linux bug in mprotect
per POSIX: The mprotect() function shall change the access protections
to be that specified by prot for those whole pages containing any part
of the address space of the process starting at address addr and
continuing for len bytes.
on the other hand, linux mprotect fails with EINVAL if the base
address and/or length is not page-aligned, so we have to align them
before making the syscall.
Rich Felker [Tue, 28 Jun 2011 18:20:41 +0000 (14:20 -0400)]
use load address from elf header if possible
this is mostly useless for shared libs (though it could help for
prelink-like purposes); the intended use case is for adding support
for calling the dynamic linker directly to run a program, as in:
./libc.so ./a.out foo
Rich Felker [Mon, 27 Jun 2011 01:21:04 +0000 (21:21 -0400)]
fix resolving symbols in objects loaded in RTLD_LOCAL mode
basically we temporarily make the library and all its dependencies
part of the global namespace but only for the duration of performing
relocations, then return them to their former state.
Rich Felker [Sun, 26 Jun 2011 21:39:17 +0000 (17:39 -0400)]
error handling in dynamic linking
some of the code is not yet used, and is in preparation for dlopen
which needs to be able to handle failure loading libraries without
terminating the program.
Rich Felker [Fri, 24 Jun 2011 02:04:06 +0000 (22:04 -0400)]
prepare support for LD_LIBRARY_PATH (checking suid/sgid safety)
the use of this test will be much stricter than glibc and other
typical implementations; the environment will not be honored
whatsoever unless the program is confirmed non-suid/sgid by the aux
vector the kernel passed in. no fallback to slow syscall-based
checking is used if the kernel fails to provide the information; we
simply assume the worst (suid) in this case and refuse to honor
environment.
Rich Felker [Sat, 18 Jun 2011 23:48:42 +0000 (19:48 -0400)]
experimental dynamic linker!
some notes:
- library search path is hard coded
- x86_64 code is untested and may not work
- dlopen/dlsym is not yet implemented
- relocations in read-only memory won't work
Rich Felker [Tue, 14 Jun 2011 05:35:51 +0000 (01:35 -0400)]
fix race condition in pthread_kill
if thread id was reused by the kernel between the time pthread_kill
read it from the userspace pthread_t object and the time of the tgkill
syscall, a signal could be sent to the wrong thread. the tgkill
syscall was supposed to prevent this race (versus the old tkill
syscall) but it can't; it can only help in the case where the tid is
reused in a different process, but not when the tid is reused in the
same process.
the only solution i can see is an extra lock to prevent threads from
exiting while another thread is trying to pthread_kill them. it should
be very very cheap in the non-contended case.
Rich Felker [Sun, 12 Jun 2011 19:58:15 +0000 (15:58 -0400)]
floating point environment, untested
at present the i386 code does not support sse floating point, which is
not part of the standard i386 abi. while it may be desirable to
support it later, doing so will reduce performance and require some
tricks to probe if sse support is present.
this first commit is i386-only, but it should be trivial to port the
asm to x86_64.
Rich Felker [Sun, 12 Jun 2011 14:53:42 +0000 (10:53 -0400)]
malloc: cast size down to int in bin_index functions
even if size_t was 32-bit already, the fact that the value was
unsigned and that gcc is too stupid to figure out it would be positive
as a signed quantity (due to the immediately-prior arithmetic and
conditionals) results in gcc compiling the integer-to-float conversion
as zero extension to 64 bits followed by an "fildll" (64 bit)
instruction rather than a simple "fildl" (32 bit) instruction on x86.
reportedly fildll is very slow on certain p4-class machines; even if
not, the new code is slightly smaller.
Rich Felker [Tue, 7 Jun 2011 15:26:42 +0000 (11:26 -0400)]
use __WCHAR_TYPE__ on i386 if it is defined
unfortunately traditional i386 practice was to use "long" rather than
"int" for wchar_t, despite the latter being much more natural and
logical. we followed this practice, but it seems some compilers (clang
and maybe certain gcc builds or others too..?) have switched to using
int, resulting in spurious pointer type mismatches when L"..." wide
strings are used. the best solution I could find is to use the
compiler's definition of wchar_t if it exists, and otherwise fallback
to the traditional definition.
there's no point in duplicating this approach on 64-bit archs, as
their only 32-bit type is int.
Rich Felker [Mon, 6 Jun 2011 22:04:28 +0000 (18:04 -0400)]
fix handling of d_name in struct dirent
basically there are 3 choices for how to implement this variable-size
string member:
1. C99 flexible array member: breaks using dirent.h with pre-C99 compiler.
2. old way: length-1 string: generates array bounds warnings in caller.
3. new way: length-NAME_MAX string. no problems, simplifies all code.
of course the usable part in the pointer returned by readdir might be
shorter than NAME_MAX+1 bytes, but that is allowed by the standard and
doesn't hurt anything.
Rich Felker [Sun, 5 Jun 2011 23:29:52 +0000 (19:29 -0400)]
safety fix for glob's vla usage: disallow patterns longer than PATH_MAX
this actually inadvertently disallows some valid patterns with
redundant / or * characters, but it's better than allowing unbounded
vla allocation.
eventually i'll write code to move the pattern to the stack and
eliminate redundancy to ensure that it fits in PATH_MAX at the
beginning of glob. this would also allow it to be modified in place
for passing to fnmatch rather than copied at each level of recursion.
Rich Felker [Mon, 30 May 2011 15:31:07 +0000 (11:31 -0400)]
implement pthread_[sg]etconcurrency.
there is a resource limit of 0 bits to store the concurrency level
requested. thus any positive level exceeds a resource limit, resulting
in EAGAIN. :-)