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2013-12-19fix failure of fchmod, fstat, fchdir, and fchown to produce EBADFRich Felker-2/+6
the workaround/fallback code for supporting O_PATH file descriptors when the kernel lacks support for performing these operations on them caused EBADF to get replaced by ENOENT (due to missing entry in /proc/self/fd). this is unlikely to affect real-world code (calls that might yield EBADF are generally unsafe, especially in library code) but it was breaking some test cases. the fix I've applied is something of a tradeoff: it adds one syscall to these operations on kernels where the workaround is needed. the alternative would be to catch ENOENT from the /proc lookup and translate it to EBADF, but I want to avoid doing that in the interest of not touching/depending on /proc at all in these functions as long as the kernel correctly supports the operations. this is following the general principle of isolating hacks to code paths that are taken on broken systems, and keeping the code for correct systems completely hack-free.
2013-12-12include cleanups: remove unused headers and add feature test macrosSzabolcs Nagy-1/+2
2013-08-02make fchdir, fchmod, fchown, and fstat support O_PATH file descriptorsRich Felker-3/+19
on newer kernels, fchdir and fstat work anyway. this same fix should be applied to any other syscalls that are similarly affected. with this change, the current definitions of O_SEARCH and O_EXEC as O_PATH are mostly conforming to POSIX requirements. the main remaining issue is that O_NOFOLLOW has different semantics.
2013-08-02debloat code that depends on /proc/self/fd/%d with shared functionRich Felker-1/+3
I intend to add more Linux workarounds that depend on using these pathnames, and some of them will be in "syscall" functions that, from an anti-bloat standpoint, should not depend on the whole snprintf framework.
2013-08-02work around linux's lack of flags argument to fchmodat syscallRich Felker-1/+29
previously, the AT_SYMLINK_NOFOLLOW flag was ignored, giving dangerously incorrect behavior -- the target of the symlink had its modes changed to the modes (usually 0777) intended for the symlink). this issue was amplified by the fact that musl provides lchmod, as a wrapper for fchmodat, which some archival programs take as a sign that symlink modes are supported and thus attempt to use. emulating AT_SYMLINK_NOFOLLOW was a difficult problem, and I originally believed it could not be solved, at least not without depending on kernels newer than 3.5.x or so where O_PATH works halfway well. however, it turns out that accessing O_PATH file descriptors via their pseudo-symlink entries in /proc/self/fd works much better than trying to use the fd directly, and works even on older kernels. moreover, the kernel has permanently pegged these references to the inode obtained by the O_PATH open, so there should not be race conditions with the file being moved, deleted, replaced, etc.
2013-07-19improve [f]stat[v]fs functions, and possibly work around old kernelsRich Felker-2/+5
the main aim of this patch is to ensure that if not all fields are filled in, they contain zeros, so as not to confuse applications. reportedly some older kernels, including commonly used openvz kernels, lack the f_flags field, resulting in applications reading random junk as the mount flags; the common symptom seems to be wrongly considering the filesystem to be mounted read-only and refusing to operate. glibc has some amazingly ugly fallback code to get the mount flags for old kernels, but having them really is not that important anyway; what matters most is not presenting incorrect flags to the application. I have also aimed to fill in some fields of statvfs that were previously missing, and added code to explicitly zero the reserved space at the end of the structure, which will make things easier in the future if this space someday needs to be used.
2013-05-16fix mknod and mknodat to accept large dev_t valuesRich Felker-5/+2
support for these was recently added to sysmacros.h. note that the syscall argument is a long, despite dev_t being 64-bit, so on 32-bit archs the high bits will be lost. it appears the high bits are just glibc silliness and not part of the kernel api, anyway, but it's nice that we have them there for future expansion if needed.
2012-12-06add obsolete futimesat()rofl0r-0/+9
this function is obsolete, however it's available as a syscall and as such qemu userspace emulation tries to forward it to the host kernel.
2012-09-06use restrict everywhere it's required by c99 and/or posix 2008Rich Felker-4/+4
to deal with the fact that the public headers may be used with pre-c99 compilers, __restrict is used in place of restrict, and defined appropriately for any supported compiler. we also avoid the form [restrict] since older versions of gcc rejected it due to a bug in the original c99 standard, and instead use the form *restrict.
2012-05-31add LSB ABI __xstat, etc. junkRich Felker-0/+36
2011-09-20fix statvfs.c to match new fsid_t definitionRich Felker-1/+1
2011-09-19fix the definition of struct statvfs to match lsb abiRich Felker-19/+46
at the same time, make struct statfs match the traditional definition and make it more useful, especially the fsid_t stuff.
2011-04-05fix (hopefully) statvfs breakage on x86_64 that resulted from fixing i386...Rich Felker-2/+10
2011-04-03fix statvfs syscalls (missing size argument)Rich Felker-2/+2
2011-03-20global cleanup to use the new syscall interfaceRich Felker-15/+15
2011-02-27implement futimens and utimensatRich Felker-0/+13
2011-02-17add portable lchown (trivial to support and a few ancient things want it..)Rich Felker-0/+7
2011-02-15finish moving 32-bit-specific junk out of source files.Rich Felker-6/+6
2011-02-12initial check-in, version 0.5.0v0.5.0Rich Felker-0/+137