linux/arch/arc/include/asm
Linus Torvalds 30c44659f4 Merge branch 'strscpy' of git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile
Pull strscpy string copy function implementation from Chris Metcalf.

Chris sent this during the merge window, but I waffled back and forth on
the pull request, which is why it's going in only now.

The new "strscpy()" function is definitely easier to use and more secure
than either strncpy() or strlcpy(), both of which are horrible nasty
interfaces that have serious and irredeemable problems.

strncpy() has a useless return value, and doesn't NUL-terminate an
overlong result.  To make matters worse, it pads a short result with
zeroes, which is a performance disaster if you have big buffers.

strlcpy(), by contrast, is a mis-designed "fix" for strlcpy(), lacking
the insane NUL padding, but having a differently broken return value
which returns the original length of the source string.  Which means
that it will read characters past the count from the source buffer, and
you have to trust the source to be properly terminated.  It also makes
error handling fragile, since the test for overflow is unnecessarily
subtle.

strscpy() avoids both these problems, guaranteeing the NUL termination
(but not excessive padding) if the destination size wasn't zero, and
making the overflow condition very obvious by returning -E2BIG.  It also
doesn't read past the size of the source, and can thus be used for
untrusted source data too.

So why did I waffle about this for so long?

Every time we introduce a new-and-improved interface, people start doing
these interminable series of trivial conversion patches.

And every time that happens, somebody does some silly mistake, and the
conversion patch to the improved interface actually makes things worse.
Because the patch is mindnumbing and trivial, nobody has the attention
span to look at it carefully, and it's usually done over large swatches
of source code which means that not every conversion gets tested.

So I'm pulling the strscpy() support because it *is* a better interface.
But I will refuse to pull mindless conversion patches.  Use this in
places where it makes sense, but don't do trivial patches to fix things
that aren't actually known to be broken.

* 'strscpy' of git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile:
  tile: use global strscpy() rather than private copy
  string: provide strscpy()
  Make asm/word-at-a-time.h available on all architectures
2015-10-04 16:31:13 +01:00
..
arcregs.h ARCv2: Support IO Coherency and permutations involving L1 and L2 caches 2015-08-20 18:11:17 +05:30
asm-offsets.h
atomic.h Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2015-09-03 15:46:07 -07:00
barrier.h ARCv2: barriers 2015-06-25 06:00:17 +05:30
bitops.h ARC: Make ARC bitops "safer" (add anti-optimization) 2015-07-09 17:36:32 +05:30
bug.h ARC: BUG() dumps stack after @msg (@msg now same as in generic BUG)) 2014-10-13 14:46:18 +05:30
cache.h ARCv2: Support IO Coherency and permutations involving L1 and L2 caches 2015-08-20 18:11:17 +05:30
cacheflush.h ARC: fold ___flush_dcache_page into __flush_dcache_page 2015-05-19 11:27:13 +05:30
checksum.h ARC: Checksum/byteorder/swab routines 2013-02-11 20:00:34 +05:30
clk.h ARC: [DeviceTree] Convert some Kconfig items to runtime values 2013-02-15 23:15:56 +05:30
cmpxchg.h ARC: add/fix some comments in code - no functional change 2015-08-20 19:05:49 +05:30
current.h ARC: remove extraneous __KERNEL__ guards 2014-10-13 14:46:20 +05:30
delay.h ARCv2: Adhere to Zero Delay loop restriction 2015-06-22 14:06:56 +05:30
disasm.h ARC: disassembly (needed by kprobes/kgdb/unaligned-access-emul) 2013-02-15 23:16:04 +05:30
dma-mapping.h Merge branch 'akpm' (patches from Andrew) 2015-07-01 17:47:51 -07:00
dma.h ARC: I/O and DMA Mappings 2013-02-15 23:15:54 +05:30
elf.h ARCv2: Support for ARCv2 ISA and HS38x cores 2015-06-22 14:06:55 +05:30
entry-arcv2.h ARCv2: Support for ARCv2 ISA and HS38x cores 2015-06-22 14:06:55 +05:30
entry-compact.h ARC: intc: split into ARCompact ISA specific, common bits 2015-06-19 18:09:40 +05:30
entry.h ARCv2: STAR 9000808988: signals involving Delay Slot 2015-06-22 14:06:55 +05:30
exec.h ARC: Fundamental ARCH data-types/defines 2013-02-11 20:00:34 +05:30
futex.h ARC: change some branchs to jumps to resolve linkage errors 2015-08-20 18:53:15 +05:30
io.h - Support for HS38 cores based on ARCv2 ISA 2015-07-01 09:24:26 -07:00
irq.h ARCv2: SMP: Support ARConnect (MCIP) for Inter-Core-Interrupts et al 2015-06-22 14:06:56 +05:30
irqflags-arcv2.h ARCv2: STAR 9000814690: Really Re-enable interrupts to avoid deadlocks 2015-06-22 14:06:55 +05:30
irqflags-compact.h ARCv2: Support for ARCv2 ISA and HS38x cores 2015-06-22 14:06:55 +05:30
irqflags.h ARCv2: Support for ARCv2 ISA and HS38x cores 2015-06-22 14:06:55 +05:30
Kbuild Merge branch 'strscpy' of git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile 2015-10-04 16:31:13 +01:00
kdebug.h ARC: Fundamental ARCH data-types/defines 2013-02-11 20:00:34 +05:30
kgdb.h ARC: Update order of registers in KGDB to match GDB 7.5 2014-10-13 14:46:20 +05:30
kprobes.h ARC: Remove explicit passing around of ECR 2013-06-26 15:30:50 +05:30
linkage.h ARC: switch to generic ENTRY/END assembler annotations 2014-03-26 14:31:28 +05:30
mach_desc.h arc: use common of_flat_dt_match_machine 2013-10-09 20:03:55 -05:00
mcip.h ARCv2: SMP: clocksource: Enable Global Real Time counter 2015-06-22 14:06:57 +05:30
mmu_context.h ARC: [SMP] TLB flush 2013-11-06 10:41:45 +05:30
mmu.h ARCv2: MMUv4: TLB programming Model changes 2015-06-22 14:06:55 +05:30
module.h ARC: DWARF2 .debug_frame based stack unwinder 2013-02-15 23:16:03 +05:30
mutex.h ARC: SMP support 2013-02-15 23:16:02 +05:30
page.h ARC: [mm] Make stack/heap Non-executable by default 2013-06-22 19:23:20 +05:30
perf_event.h ARCv2: perf: Finally introduce HS perf unit 2015-08-27 14:59:07 +05:30
pgalloc.h arc: handle pgtable_page_ctor() fail 2013-11-15 09:32:16 +09:00
pgtable.h ARCv2: MMUv4: TLB programming Model changes 2015-06-22 14:06:55 +05:30
processor.h ARC: mm: document system mem map clearly 2015-06-19 18:09:29 +05:30
ptrace.h ARC: Make pt_regs regs unsigned 2015-08-05 11:48:21 +05:30
sections.h of/fdt: consolidate built-in dtb section variables 2014-04-30 00:59:13 -05:00
segment.h ARC: uaccess friends 2013-02-11 20:00:31 +05:30
serial.h ARC: Dynamically determine BASE_BAUD from DeviceTree 2015-02-02 17:08:37 +05:30
setup.h ARC: RIP @running_on_hw 2014-10-13 14:46:17 +05:30
shmparam.h ARC: [mm] Aliasing VIPT dcache support 4/4 2013-05-09 22:00:57 +05:30
smp.h ARC: Allow SMP kernel to build/boot on UP-only infrastructure 2014-09-27 14:49:01 +05:30
spinlock_types.h ARC: LLOCK/SCOND based rwlock 2015-08-04 09:26:33 +05:30
spinlock.h ARCv2: spinlock/rwlock/atomics: reduce 1 instruction in exponential backoff 2015-08-07 13:56:16 +05:30
stacktrace.h ARC: Make arc_unwind_core accessible externally 2015-02-27 10:15:00 +05:30
string.h ARC: remove extraneous __KERNEL__ guards 2014-10-13 14:46:20 +05:30
switch_to.h ARC: Process-creation/scheduling/idle-loop 2013-02-11 20:00:38 +05:30
syscall.h ARC: stop using pt_regs->orig_r8 2013-06-22 19:23:26 +05:30
syscalls.h ARC: remove extraneous __KERNEL__ guards 2014-10-13 14:46:20 +05:30
thread_info.h ARCv2: Support for ARCv2 ISA and HS38x cores 2015-06-22 14:06:55 +05:30
timex.h ARC: Timers/counters/delay management 2013-02-11 20:00:39 +05:30
tlb-mmu1.h ARC: Disintegrate arcregs.h 2013-06-22 13:46:42 +05:30
tlb.h ARC: Disintegrate arcregs.h 2013-06-22 13:46:42 +05:30
tlbflush.h ARC: [SMP] TLB flush 2013-11-06 10:41:45 +05:30
uaccess.h ARCv2: Adhere to Zero Delay loop restriction 2015-06-22 14:06:56 +05:30
unaligned.h ARC: rename kconfig option for unaligned emulation 2014-10-13 14:46:15 +05:30
unwind.h ARC: DWARF2 .debug_frame based stack unwinder 2013-02-15 23:16:03 +05:30