The errors are introduced in "Make pthread join_state not protected by g_thread_list_lock".
Bug: 19636317
Change-Id: I58ae9711da94bfbac809abfd81311eeb70301a4b
Bionic's getauxval(...) implementation returns zero when entries are
missing. Zero can be a valid value, so there is no unambiguous way of
detecting an error. Since glibc 2.19, errno is set to ENOENT when an
entry is missing to make it possible to detect this. Bionic should match
this behavior as code in the Linux ecosystem will start relying on it to
check for the presence of newly added entries.
Change-Id: Ic1efe29bc45fc87489274c96c4d2193f3a7b8854
Signed-off-by: Daniel Micay <danielmicay@gmail.com>
1. Move the representation of thread join_state from pthread.attr.flag
to pthread.join_state. This clarifies thread state change.
2. Use atomic operations for pthread.join_state. So we don't need to
protect it by g_thread_list_lock. g_thread_list_lock will be reduced
to only protect g_thread_list or even removed in further changes.
Bug: 19636317
Change-Id: I31fb143a7c69508c7287307dd3b0776993ec0f43
Make this change because I think it is more reasonable to check stack info
in pthread_getattr_np. I believe pthread_attr_t is not tied with any thread,
and can't have a flag saying who using it is the main thread.
This change also helps refactor of g_thread_list_lock.
Bug: 19636317
Change-Id: Iedbb85a391ac3e1849dd036d01445dac4bc63db9
The kernel system call faccessat() does not have any flags arguments,
so passing flags to the kernel is currently ignored.
Fix the kernel system call so that no flags argument is passed in.
Ensure that we don't support AT_SYMLINK_NOFOLLOW. This non-POSIX
(http://pubs.opengroup.org/onlinepubs/9699919799/functions/access.html)
flag is a glibc extension, and has non-intuitive, error prone behavior.
For example, consider the following code:
symlink("foo.is.dangling", "foo");
if (faccessat(AT_FDCWD, "foo", R_OK, AT_SYMLINK_NOFOLLOW) == 0) {
int fd = openat(AT_FDCWD, "foo", O_RDONLY | O_NOFOLLOW);
}
The faccessat() call in glibc will return true, but an attempt to
open the dangling symlink will end up failing. GLIBC documents this
as returning the access mode of the symlink itself, which will
always return true for any symlink on Linux.
Some further discussions of this are at:
* http://lists.landley.net/pipermail/toybox-landley.net/2014-September/003617.html
* http://permalink.gmane.org/gmane.linux.lib.musl.general/6952
AT_SYMLINK_NOFOLLOW seems broken by design. I suspect this is why this
function was never added to POSIX. (note that "access" is pretty much
broken by design too, since it introduces a race condition between
check and action). We shouldn't support this until it's clearly
documented by POSIX or we can have it produce intuitive results.
Don't support AT_EACCESS for now. Implementing it is complicated, and
pretty much useless on Android, since we don't have setuid binaries.
See http://git.musl-libc.org/cgit/musl/commit/?id=0a05eace163cee9b08571d2ff9d90f5e82d9c228
for how an implementation might look.
Bug: 18867827
Change-Id: I25b86c5020f3152ffa3ac3047f6c4152908d0e04
The overflow's actually in the generic C implementation of memchr.
While I'm here, let's switch our generic memrchr to the OpenBSD version too.
Bug: https://code.google.com/p/android/issues/detail?id=147048
Change-Id: I296ae06a1ee196d2c77c95a22f11ee4d658962da
The .note.android.ident section is only used by GDB, which doesn't
care what section type the section is, but it would be convenient
for readelf -n to be able to find the section too.
The old way of getting the .note.android.ident section to be of type
SH_NOTE involved compiling from .c to .s using gcc, running sed to
change progbits to note, and then compiling from .s to .o using gcc.
Since crtbrand.c only contains a section containing data, a
crtbrand.S can be checked in that will compile on all platforms,
avoiding the need for sed.
Also add crtbrand.o to crtbegin_so.o so that libraries also get
the note, and to the crt workaround in arm libc.so.
Change-Id: Ica71942a6af4553b56978ceaa288b3f4c15ebfa2
crtbrand.c was compiled to a .s file, run through a sed script
to translate a %progbits to %note, and the compiled to .o.
However, when the sed command was copied from the original source
it was not updated to use the new name of the section (.note.ABI-tag
to .note.android.ident), so it didn't modify the file. Since the
section has been generated with type %progbits instead of %note for
two years, just delete the whole sed step.
Change-Id: Id78582e9b43b628afec4eed22a088283132f0742
In https://android-review.googlesource.com/#/c/127908/5/libc/SYSCALLS.TXT@116
Elliott said:
for LP64 these will be hidden. for LP32 we were cowards and left
them all public for compatibility (though i don't think we ever
dremeled to see whether it was needed). we don't have an easy
way to recognize additions, though, so we can't prevent adding
new turds.
Add a mechanism to prevent the adding of new turds, and use that
mechanism on the fchmod/fchmodat system calls.
Bug: 19233951
Change-Id: I98f98345970b631a379f348df57858f9fc3d57c0
Many libc functions have an option to not follow symbolic
links. This is useful to avoid security sensitive code
from inadvertantly following attacker supplied symlinks
and taking inappropriate action on files it shouldn't.
For example, open() has O_NOFOLLOW, chown() has
lchown(), stat() has lstat(), etc.
There is no such equivalent function for chmod(), such as lchmod().
To address this, POSIX introduced fchmodat(AT_SYMLINK_NOFOLLOW),
which is intended to provide a way to perform a chmod operation
which doesn't follow symlinks.
Currently, the Linux kernel doesn't implement AT_SYMLINK_NOFOLLOW.
In GLIBC, attempting to use the AT_SYMLINK_NOFOLLOW flag causes
fchmodat to return ENOTSUP. Details are in "man fchmodat".
Bionic currently differs from GLIBC in that AT_SYMLINK_NOFOLLOW
is silently ignored and treated as if the flag wasn't present.
This patch provides a userspace implementation of
AT_SYMLINK_NOFOLLOW for bionic. Using open(O_PATH | O_NOFOLLOW),
we can provide a way to atomically change the permissions on
files without worrying about race conditions.
As part of this change, we add support for fchmod on O_PATH
file descriptors, because it's relatively straight forward
and could be useful in the future.
The basic idea behind this implementation comes from
https://sourceware.org/bugzilla/show_bug.cgi?id=14578 , specifically
comment #10.
Change-Id: I1eba0cdb2c509d9193ceecf28f13118188a3cfa7
