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  1. 11 9月, 2015 1 次提交
  3. 16 4月, 2015 2 次提交
    • R
      lib/string_helpers.c: change semantics of string_escape_mem · 41416f23
      由 Rasmus Villemoes 提交于 
      The current semantics of string_escape_mem are inadequate for one of its
current users, vsnprintf().  If that is to honour its contract, it must
know how much space would be needed for the entire escaped buffer, and
string_escape_mem provides no way of obtaining that (short of allocating a
large enough buffer (~4 times input string) to let it play with, and
that's definitely a big no-no inside vsnprintf).

So change the semantics for string_escape_mem to be more snprintf-like:
Return the size of the output that would be generated if the destination
buffer was big enough, but of course still only write to the part of dst
it is allowed to, and (contrary to snprintf) don't do '\0'-termination.
It is then up to the caller to detect whether output was truncated and to
append a '\0' if desired.  Also, we must output partial escape sequences,
otherwise a call such as snprintf(buf, 3, "%1pE", "\123") would cause
printf to write a \0 to buf[2] but leaving buf[0] and buf[1] with whatever
they previously contained.

This also fixes a bug in the escaped_string() helper function, which used
to unconditionally pass a length of "end-buf" to string_escape_mem();
since the latter doesn't check osz for being insanely large, it would
happily write to dst.  For example, kasprintf(GFP_KERNEL, "something and
then %pE", ...); is an easy way to trigger an oops.

In test-string_helpers.c, the -ENOMEM test is replaced with testing for
getting the expected return value even if the buffer is too small.  We
also ensure that nothing is written (by relying on a NULL pointer deref)
if the output size is 0 by passing NULL - this has to work for
kasprintf("%pE") to work.

In net/sunrpc/cache.c, I think qword_add still has the same semantics.
Someone should definitely double-check this.

In fs/proc/array.c, I made the minimum possible change, but longer-term it
should stop poking around in seq_file internals.

[andriy.shevchenko@linux.intel.com: simplify qword_add]
[andriy.shevchenko@linux.intel.com: add missed curly braces]
Signed-off-by: NRasmus Villemoes <linux@rasmusvillemoes.dk>
Acked-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      41416f23
    • R
      lib/string_helpers.c: refactor string_escape_mem · 3aeddc7d
      由 Rasmus Villemoes 提交于 
      When printf is given the format specifier %pE, it needs a way of obtaining
the total output size that would be generated if the buffer was large
enough, and string_escape_mem doesn't easily provide that.  This is a
refactorization of string_escape_mem in preparation of changing its
external API to provide that information.

The somewhat ugly early returns and subsequent seemingly redundant
conditionals are to make the following patch touch as little as possible
in string_helpers.c while still preserving the current behaviour of never
outputting partial escape sequences.  That behaviour must also change for
%pE to work as one expects from every other printf specifier.
Signed-off-by: NRasmus Villemoes <linux@rasmusvillemoes.dk>
Acked-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      3aeddc7d
  5. 11 4月, 2015 1 次提交
    • J
      sd, mmc, virtio_blk, string_helpers: fix block size units · b9f28d86
      由 James Bottomley 提交于 
      The current string_get_size() overflows when the device size goes over
2^64 bytes because the string helper routine computes the suffix from
the size in bytes.  However, the entirety of Linux thinks in terms of
blocks, not bytes, so this will artificially induce an overflow on very
large devices.  Fix this by making the function string_get_size() take
blocks and the block size instead of bytes.  This should allow us to
keep working until the current SCSI standard overflows.

Also fix virtio_blk and mmc (both of which were also artificially
multiplying by the block size to pass a byte side to string_get_size()).

The mathematics of this is pretty simple:  we're taking a product of
size in blocks (S) and block size (B) and trying to re-express this in
exponential form: S*B = R*N^E (where N, the exponent is either 1000 or
1024) and R < N.  Mathematically, S = RS*N^ES and B=RB*N^EB, so if RS*RB
< N it's easy to see that S*B = RS*RB*N^(ES+EB).  However, if RS*BS > N,
we can see that this can be re-expressed as RS*BS = R*N (where R =
RS*BS/N < N) so the whole exponent becomes R*N^(ES+EB+1)

[jejb: fix incorrect 32 bit do_div spotted by kbuild test robot <fengguang.wu@intel.com>]
Acked-by: NUlf Hansson <ulf.hansson@linaro.org>
Reviewed-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NJames Bottomley <JBottomley@Odin.com>
      b9f28d86
  7. 13 2月, 2015 3 次提交
  9. 14 10月, 2014 2 次提交
  11. 07 8月, 2014 1 次提交
  13. 01 5月, 2013 1 次提交
  15. 30 5月, 2012 1 次提交
  17. 08 3月, 2012 1 次提交
  19. 24 10月, 2008 1 次提交
    • H
      [SCSI] lib: string_get_size(): don't hang on zero; no decimals on exact · a8659597
      由 H. Peter Anvin 提交于 
      We would hang forever when passing a zero to string_get_size().
Furthermore, string_get_size() would produce decimals on a value small
enough to be exact.  Finally, a few formatting issues are inconsistent
with standard SI style guidelines.

- If the value is less than the divisor, skip the entire rounding
  step.  This prints out all small values including zero as integers,
  without decimals.
- Add a space between the value and the symbol for the unit,
  consistent with standard SI practice.
- Lower case k in kB since we are talking about powers of 10.
- Finally, change "int" to "unsigned int" in one place to shut up a
  gcc warning when compiling the code out-of-kernel for testing.
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>
      a8659597
  21. 04 10月, 2008 1 次提交