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2015-04-15lib/string_helpers.c: change semantics of string_escape_memRasmus Villemoes1-42/+7
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: Rasmus Villemoes <linux@rasmusvillemoes.dk> Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-15lib/string_helpers.c: refactor string_escape_memRasmus Villemoes1-103/+105
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: Rasmus Villemoes <linux@rasmusvillemoes.dk> Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-12libstring_helpers.c:string_get_size(): return voidRasmus Villemoes1-6/+4
string_get_size() was documented to return an error, but in fact always returned 0. Since the output always fits in 9 bytes, just document that and let callers do what they do now: pass a small stack buffer and ignore the return value. Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-12lib/string_helpers.c:string_get_size(): use 32 bit arithmetic when possibleRasmus Villemoes1-5/+4
The remainder from do_div is always a u32, and after size has been reduced to be below 1000 (or 1024), it certainly fits in u32. So both remainder and sf_cap can be made u32s, the format specifiers can be simplified (%lld wasn't the right thing to use for _unsigned_ long long anyway), and we can replace a do_div with an ordinary 32/32 bit division. Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-12lib/string_helpers.c:string_get_size(): remove redundant prefixesRasmus Villemoes1-4/+3
While commit 3c9f3681d0b4 ("[SCSI] lib: add generic helper to print sizes rounded to the correct SI range") says that Z and Y are included in preparation for 128 bit computers, they just waste .text currently. If and when we get u128, string_get_size needs updating anyway (and ISO needs to come up with four more prefixes). Also there's no need to include and test for the NULL sentinel; once we reach "E" size is at most 18. [The test is also wrong; it should be units_str[units][i+1]; if we've reached NULL we're already doomed.] Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: James Bottomley <James.Bottomley@HansenPartnership.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-14lib / string_helpers: introduce string_escape_mem()Andy Shevchenko1-0/+274
This is almost the opposite function to string_unescape(). Nevertheless it handles \0 and could be used for any byte buffer. The documentation is supplied together with the function prototype. The test cases covers most of the scenarios and would be expanded later on. [akpm@linux-foundation.org: avoid 1k stack consumption] Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: "John W . Linville" <linville@tuxdriver.com> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Joe Perches <joe@perches.com> Cc: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-14lib / string_helpers: move documentation to c-fileAndy Shevchenko1-0/+38
The introduced function string_escape_mem() is a kind of opposite to string_unescape. We have several users of such functionality each of them created custom implementation. The series contains clean up of test suite, adding new call, and switching few users to use it via %*pE specifier. Test suite covers all of existing and most of potential use cases. This patch (of 11): The documentation of API belongs to c-file. This patch moves it accordingly. There is no functional change. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: "John W . Linville" <linville@tuxdriver.com> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Joe Perches <joe@perches.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-06lib/string_helpers.c: constify static arraysMathias Krause1-6/+9
Complement commit 68aecfb97978 ("lib/string_helpers.c: make arrays static") by making the arrays const -- not only pointing to const strings. This moves them out of the data section to the r/o data section: text data bss dec hex filename 1150 176 0 1326 52e lib/string_helpers.old.o 1326 0 0 1326 52e lib/string_helpers.new.o Signed-off-by: Mathias Krause <minipli@googlemail.com> Cc: James Bottomley <James.Bottomley@HansenPartnership.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-30lib/string_helpers: introduce generic string_unescapeAndy Shevchenko1-0/+133
There are several places in kernel where modules unescapes input to convert C-Style Escape Sequences into byte codes. The patch provides generic implementation of such approach. Test cases are also included into the patch. [akpm@linux-foundation.org: clarify comment] [akpm@linux-foundation.org: export get_random_int() to modules] Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Samuel Thibault <samuel.thibault@ens-lyon.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jason Baron <jbaron@redhat.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: William Hubbs <w.d.hubbs@gmail.com> Cc: Chris Brannon <chris@the-brannons.com> Cc: Kirk Reiser <kirk@braille.uwo.ca> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-05-29lib/string_helpers.c: make arrays staticAndrew Morton1-4/+4
Moving these arrays into static storage shrinks the kernel a bit: text data bss dec hex filename 723 112 64 899 383 lib/string_helpers.o 516 272 64 852 354 lib/string_helpers.o Cc: James Bottomley <James.Bottomley@HansenPartnership.com> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-03-07lib: reduce the use of module.h wherever possiblePaul Gortmaker1-1/+1
For files only using THIS_MODULE and/or EXPORT_SYMBOL, map them onto including export.h -- or if the file isn't even using those, then just delete the include. Fix up any implicit include dependencies that were being masked by module.h along the way. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2008-10-23[SCSI] lib: string_get_size(): don't hang on zero; no decimals on exactH. Peter Anvin1-15/+19
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: H. Peter Anvin <hpa@zytor.com> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-10-03[SCSI] lib: add generic helper to print sizes rounded to the correct SI rangeJames Bottomley1-0/+64
This patch adds the ability to print sizes in either units of 10^3 (SI) or 2^10 (Binary) units. It rounds up to three significant figures and can be used for either memory or storage capacities. Oh, and I'm fully aware that 64 bits is only 16EiB ... the Zetta and Yotta units are added for future proofing against the day we have 128 bit computers ... [fujita.tomonori@lab.ntt.co.jp: fix missed unsigned long long cast] Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>