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  1. 06 5月, 2012 1 次提交
  3. 21 3月, 2012 2 次提交
  5. 26 2月, 2012 1 次提交
    • I
      autofs: work around unhappy compat problem on x86-64 · a32744d4
      由 Ian Kent 提交于 
      When the autofs protocol version 5 packet type was added in commit
5c0a32fc ("autofs4: add new packet type for v5 communications"), it
obvously tried quite hard to be word-size agnostic, and uses explicitly
sized fields that are all correctly aligned.

However, with the final "char name[NAME_MAX+1]" array at the end, the
actual size of the structure ends up being not very well defined:
because the struct isn't marked 'packed', doing a "sizeof()" on it will
align the size of the struct up to the biggest alignment of the members
it has.

And despite all the members being the same, the alignment of them is
different: a "__u64" has 4-byte alignment on x86-32, but native 8-byte
alignment on x86-64.  And while 'NAME_MAX+1' ends up being a nice round
number (256), the name[] array starts out a 4-byte aligned.

End result: the "packed" size of the structure is 300 bytes: 4-byte, but
not 8-byte aligned.

As a result, despite all the fields being in the same place on all
architectures, sizeof() will round up that size to 304 bytes on
architectures that have 8-byte alignment for u64.

Note that this is *not* a problem for 32-bit compat mode on POWER, since
there __u64 is 8-byte aligned even in 32-bit mode.  But on x86, 32-bit
and 64-bit alignment is different for 64-bit entities, and as a result
the structure that has exactly the same layout has different sizes.

So on x86-64, but no other architecture, we will just subtract 4 from
the size of the structure when running in a compat task.  That way we
will write the properly sized packet that user mode expects.

Not pretty.  Sadly, this very subtle, and unnecessary, size difference
has been encoded in user space that wants to read packets of *exactly*
the right size, and will refuse to touch anything else.
Reported-and-tested-by: NThomas Meyer <thomas@m3y3r.de>
Signed-off-by: NIan Kent <raven@themaw.net>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      a32744d4
  7. 20 2月, 2012 1 次提交
    • D
      Wrap accesses to the fd_sets in struct fdtable · 1dce27c5
      由 David Howells 提交于 
      Wrap accesses to the fd_sets in struct fdtable (for recording open files and
close-on-exec flags) so that we can move away from using fd_sets since we
abuse the fd_set structs by not allocating the full-sized structure under
normal circumstances and by non-core code looking at the internals of the
fd_sets.

The first abuse means that use of FD_ZERO() on these fd_sets is not permitted,
since that cannot be told about their abnormal lengths.

This introduces six wrapper functions for setting, clearing and testing
close-on-exec flags and fd-is-open flags:

	void __set_close_on_exec(int fd, struct fdtable *fdt);
	void __clear_close_on_exec(int fd, struct fdtable *fdt);
	bool close_on_exec(int fd, const struct fdtable *fdt);
	void __set_open_fd(int fd, struct fdtable *fdt);
	void __clear_open_fd(int fd, struct fdtable *fdt);
	bool fd_is_open(int fd, const struct fdtable *fdt);

Note that I've prepended '__' to the names of the set/clear functions because
they require the caller to hold a lock to use them.

Note also that I haven't added wrappers for looking behind the scenes at the
the array.  Possibly that should exist too.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Link: http://lkml.kernel.org/r/20120216174942.23314.1364.stgit@warthog.procyon.org.ukSigned-off-by: NH. Peter Anvin <hpa@zytor.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
      1dce27c5
  9. 14 2月, 2012 1 次提交
  11. 14 1月, 2012 1 次提交
  13. 11 1月, 2012 3 次提交
    • A
      autofs4: deal with autofs4_write/autofs4_write races · d668dc56
      由 Al Viro 提交于 
      Just serialize the actual writing of packets into pipe on
a new mutex, independent from everything else in the locking
hierarchy.  As soon as something has started feeding a piece
of packet into the pipe to daemon, we *want* everything else
about to try the same to wait until we are done.
Acked-by: NIan Kent <raven@themaw.net>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      d668dc56
    • A
      autofs4: catatonic_mode vs. notify_daemon race · 87533332
      由 Al Viro 提交于 
      we need to hold ->wq_mutex while we are forming the packet to send,
lest we have autofs4_catatonic_mode() setting wq->name.name to NULL
just as autofs4_notify_daemon() decides to memcpy() from it...

We do have check for catatonic mode immediately after that (under
->wq_mutex, as it ought to be) and packet won't be actually sent,
but it'll be too late for us if we oops on that memcpy() from NULL...

Fix is obvious - just extend the area covered by ->wq_mutex over
that switch and check whether it's catatonic *before* doing anything
else.
Acked-by: NIan Kent <raven@themaw.net>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      87533332
    • A
      autofs4: autofs4_wait() vs. autofs4_catatonic_mode() race · 4041bcdc
      由 Al Viro 提交于 
      We need to recheck ->catatonic after autofs4_wait() got ->wq_mutex
for good, or we might end up with wq inserted into queue after
autofs4_catatonic_mode() had done its thing.  It will stick there
forever, since there won't be anything to clear its ->name.name.

A bit of a complication: validate_request() drops and regains ->wq_mutex.
It actually ends up the most convenient place to stick the check into...
Acked-by: NIan Kent <raven@themaw.net>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      4041bcdc
  15. 07 1月, 2012 2 次提交
  17. 04 1月, 2012 2 次提交
  19. 02 11月, 2011 1 次提交
  21. 09 8月, 2011 2 次提交
    • L
      autofs4: fix debug printk warning uncovered by cleanup · 2f84dd70
      由 Linus Torvalds 提交于 
      The previous comit made the autofs4 debug printouts check types against
the printout format, and uncovered this bug:

  fs/autofs4/waitq.c:106:2: warning: format ‘%08lx’ expects type ‘long unsigned int’, but argument 4 has type ‘autofs_wqt_t’

which is due to the insane type for wait_queue_token.  That thing should
be some fixed well-defined size (preferably just 'unsigned int' or
'u32') but for unexplained reasons it is randomly either 'unsigned long'
or 'unsigned int' depending on the architecture.

For now, cast it to 'unsigned long' for printing, the way we do
elsewhere.  Somebody else can try to explain the typedef mess.

(There's a reason we don't support excessive use of typedefs in the
kernel: it's usually just a good way of confusing yourself).
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      2f84dd70
    • L
      autofs4: clean up uaotfs use of debug/info/warning printouts · c3ad9962
      由 Linus Torvalds 提交于 
      Use 'pr_debug()' for DPRINTK, which will do the proper type checking on
the arguments (without generating code) even when DEBUG isn't #defined.

Also, use the standard __VA_ARGS__ for the macros, and stop the
pointless abuse of 'do { xyz } while (0)' when the macro is already a
perfectly well-formed single statement.
Reported-by: NDavid Howells <dhowells@redhat.com>
Suggested-by: NJoe Perches <joe@perches.com>
Cc: Ian Kent <raven@themaw.net>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      c3ad9962
  23. 30 5月, 2011 1 次提交
  25. 26 5月, 2011 1 次提交
  27. 31 3月, 2011 1 次提交
  29. 25 3月, 2011 6 次提交
  31. 18 3月, 2011 1 次提交
  33. 18 1月, 2011 10 次提交
  35. 16 1月, 2011 3 次提交