v2: eliminate strscpy_truncate(); the single strscpy() API in v2 just tolerates a truncated string (while returning an error value) Also, improve some of the comparison language with strlcpy/strncpy.
This patch series addresses limitations in strncpy() and strlcpy(); both the old APIs are unpleasant, as Linus nicely summarized here: https://lkml.org/lkml/2015/4/28/570 and of course as other folks (Greg K-H and Linus again) said last year: https://plus.google.com/+gregkroahhartman/posts/1amLbuhWbh5 The proposed new API (strscpy(), for "s"afe string copy) has an easy-to-use API for detecting buffer overflow, doesn't walk past the requested copy size on the source string, and isn't subject to thread-safety attacks like the current strlcpy implementation. See patch 2/3 for more on why strscpy() is a good thing. To make strscpy() work more efficiently I did the minimum tweaking necessary to allow <asm/word-at-a-time.h> to work on all architectures, though of course individual maintainers can still make their versions more efficient as needed. It's likely not necessary for per-architecture implementations of strscpy() to be written, but I stuck with the standard __HAVE_ARCH_XXX model just for consistency with the rest of <linux/string.h>. I tested the implementation with a simple user-space harness, so I believe it is correct for the corner cases I could think of. In particular I pairwise-tested all the unaligned values of source and dest, and tested the restriction on src page-crossing at all unaligned offsets approaching the page boundary. The patch series is available to be pulled from git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile.git strscpy Chris Metcalf (3): Make asm/word-at-a-time.h available on all architectures string: provide strscpy() tile: use global strscpy() rather than private copy arch/arc/include/asm/Kbuild | 1 + arch/avr32/include/asm/Kbuild | 1 + arch/blackfin/include/asm/Kbuild | 1 + arch/c6x/include/asm/Kbuild | 1 + arch/cris/include/asm/Kbuild | 1 + arch/frv/include/asm/Kbuild | 1 + arch/hexagon/include/asm/Kbuild | 1 + arch/ia64/include/asm/Kbuild | 1 + arch/m32r/include/asm/Kbuild | 1 + arch/metag/include/asm/Kbuild | 1 + arch/microblaze/include/asm/Kbuild | 1 + arch/mips/include/asm/Kbuild | 1 + arch/mn10300/include/asm/Kbuild | 1 + arch/nios2/include/asm/Kbuild | 1 + arch/powerpc/include/asm/Kbuild | 1 + arch/s390/include/asm/Kbuild | 1 + arch/score/include/asm/Kbuild | 1 + arch/tile/gxio/mpipe.c | 33 ++------------ arch/tile/include/asm/Kbuild | 1 + arch/um/include/asm/Kbuild | 1 + arch/unicore32/include/asm/Kbuild | 1 + arch/xtensa/include/asm/Kbuild | 1 + include/asm-generic/word-at-a-time.h | 80 ++++++++++++++++++++++++++++---- include/linux/string.h | 3 ++ lib/string.c | 88 ++++++++++++++++++++++++++++++++++++ 25 files changed, 188 insertions(+), 37 deletions(-) -- 2.1.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
