linux/include/asm-generic
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
..
bitops arch: Mass conversion of smp_mb__*() 2014-04-18 14:20:48 +02:00
4level-fixup.h mm, asm-generic: define PUD_SHIFT in <asm-generic/4level-fixup.h> 2015-02-11 17:06:03 -08:00
asm-offsets.h asm-generic: Add common asm-offsets.h 2015-06-23 13:35:49 +09:00
atomic64.h atomic: Provide atomic_{or,xor,and} 2015-07-27 14:06:24 +02:00
atomic-long.h locking, asm-generic: Add _{relaxed|acquire|release}() variants for 'atomic_long_t' 2015-08-12 11:59:01 +02:00
atomic.h atomic: Collapse all atomic_{set,clear}_mask definitions 2015-07-27 14:06:24 +02:00
audit_change_attr.h audit: Modify a set of system calls in audit class definitions 2014-01-17 17:01:46 -05:00
audit_dir_write.h
audit_read.h
audit_signal.h
audit_write.h audit: Modify a set of system calls in audit class definitions 2014-01-17 17:01:46 -05:00
barrier.h locking, arch: use WRITE_ONCE()/READ_ONCE() in smp_store_release()/smp_load_acquire() 2015-08-03 10:59:30 +02:00
bitops.h arch: Prepare for smp_mb__{before,after}_atomic() 2014-04-18 11:40:30 +02:00
bitsperlong.h
bug.h bug: Make BUG() always stop the machine 2014-04-07 16:36:10 -07:00
bugs.h
cache.h
cacheflush.h
checksum.h
clkdev.h asm-generic: COMMON_CLK defines __clk_{get,put} 2014-09-25 18:00:45 -07:00
cmpxchg-local.h LLVMLinux: Remove warning about returning an uninitialized variable 2014-04-09 13:44:35 -07:00
cmpxchg.h locking/rtmutex: Drop usage of __HAVE_ARCH_CMPXCHG 2015-05-13 10:51:28 +02:00
cputime_jiffies.h sched, time: Fix build error with 64 bit cputime_t on 32 bit systems 2014-10-03 05:46:55 +02:00
cputime_nsecs.h sched, time: Fix build error with 64 bit cputime_t on 32 bit systems 2014-10-03 05:46:55 +02:00
cputime.h
current.h
delay.h
device.h
div64.h
dma-coherent.h DMA-API: Change dma_declare_coherent_memory() CPU address to phys_addr_t 2014-05-20 16:55:23 -06:00
dma-contiguous.h asm-generic: Add dma-contiguous.h 2014-09-22 13:35:51 +02:00
dma-mapping-broken.h
dma-mapping-common.h dma-mapping: consolidate dma_set_mask 2015-09-10 13:29:01 -07:00
dma.h
early_ioremap.h Merge branch 'akpm' (patches from Andrew) 2015-09-08 17:52:23 -07:00
emergency-restart.h
exec.h
fb.h
fixmap.h mm: provide early_memremap_ro to establish read-only mapping 2015-08-20 12:24:22 +01:00
ftrace.h
futex.h sched/preempt, futex: Disable preemption in UP futex_atomic_cmpxchg_inatomic() explicitly 2015-05-19 08:39:16 +02:00
getorder.h
gpio.h gpio: remove gpiod_sysfs_set_active_low 2015-05-12 10:46:53 +02:00
hardirq.h
hugetlb.h mm: Fix generic hugetlb pte check return type. 2013-10-02 20:02:35 -04:00
hw_irq.h
ide_iops.h
int-ll64.h
io-64-nonatomic-hi-lo.h readq/writeq: Add explicit lo_hi_[read|write]_q and hi_lo_[read|write]_q 2014-07-04 13:27:30 +02:00
io-64-nonatomic-lo-hi.h readq/writeq: Add explicit lo_hi_[read|write]_q and hi_lo_[read|write]_q 2014-07-04 13:27:30 +02:00
io.h x86/mm, asm-generic: Add IOMMU ioremap_uc() variant default 2015-07-21 10:47:03 +02:00
ioctl.h include/asm-generic/ioctl.h: fix _IOC_TYPECHECK sparse error 2014-06-06 16:08:13 -07:00
iomap.h x86/mm, asm-generic: Add ioremap_wt() for creating Write-Through mappings 2015-06-07 15:28:56 +02:00
irq_regs.h
irq_work.h irq_work: Introduce arch_irq_work_has_interrupt() 2014-09-13 18:38:07 +02:00
irq.h
irqflags.h
Kbuild.asm
kdebug.h
kmap_types.h
kvm_para.h
libata-portmap.h
linkage.h
local64.h
local.h
mcs_spinlock.h locking/mcs: Allow architecture specific asm files to be used for contended case 2014-02-09 21:18:52 +01:00
memory_model.h mm: fix type cast in __pfn_to_phys() 2015-09-19 03:58:10 -04:00
mm_hooks.h mm: Make arch_unmap()/bprm_mm_init() available to all architectures 2014-11-19 11:54:13 +01:00
mm-arch-hooks.h mm: clean up per architecture MM hook header files 2015-07-17 16:39:53 -07:00
mmu_context.h asm-generic: Remove asm-generic arch_bprm_mm_init() 2014-11-22 21:52:08 +01:00
mmu.h
module.h
msi.h asm-generic: Add msi.h 2014-11-23 13:01:47 +01:00
mutex-dec.h
mutex-null.h
mutex-xchg.h
mutex.h
page.h
param.h
parport.h
pci_iomap.h PCI: Add pci_iomap_wc() variants 2015-08-25 09:59:45 +02:00
pci-bridge.h
pci-dma-compat.h pci-dma-compat: add pci_zalloc_consistent helper 2014-08-08 15:57:28 -07:00
pci.h PCI: Remove unused pcibios_select_root() (again) 2015-06-08 07:56:21 -05:00
percpu.h percpu: preffity percpu header files 2014-06-17 19:12:40 -04:00
pgalloc.h
pgtable-nopmd.h
pgtable-nopud.h
pgtable.h mm: clarify that the function operates on hugepage pte 2015-06-24 17:49:44 -07:00
preempt.h sched/preempt: Fix cond_resched_lock() and cond_resched_softirq() 2015-08-03 12:21:24 +02:00
ptrace.h
qrwlock_types.h locking/rwlocks: Introduce 'qrwlocks' - fair, queued rwlocks 2014-06-06 07:58:28 +02:00
qrwlock.h locking/qrwlock: Make use of _{acquire|release|relaxed}() atomics 2015-08-12 11:59:06 +02:00
qspinlock_types.h locking/qspinlock: Optimize for smaller NR_CPUS 2015-05-08 12:36:48 +02:00
qspinlock.h locking/qspinlock/x86: Fix performance regression under unaccelerated VMs 2015-09-11 07:49:42 +02:00
resource.h asm-generic: remove _STK_LIM_MAX 2014-05-15 00:32:09 +01:00
rtc.h rtc: cmos: century support 2015-09-05 13:19:09 +02:00
rwsem.h asm-generic: rwsem: de-PPCify rwsem.h 2014-03-14 18:02:08 +00:00
seccomp.h seccomp: allow COMPAT sigreturn overrides 2015-04-17 09:04:09 -04:00
sections.h nosave: consolidate __nosave_{begin,end} in <asm/sections.h> 2014-10-09 22:26:04 -04:00
segment.h
serial.h
siginfo.h constify copy_siginfo_to_user{,32}() 2013-11-09 00:16:29 -05:00
signal.h
simd.h
sizes.h
spinlock.h
statfs.h
string.h
switch_to.h
syscall.h syscall.h: fix doc text for syscall_get_arch() 2014-09-23 16:20:00 -04:00
syscalls.h
termios-base.h
termios.h
timex.h
tlb.h mm: mmu_gather: use tlb->end != 0 only for TLB invalidation 2015-01-13 15:20:40 +13:00
tlbflush.h
topology.h
trace_clock.h
uaccess-unaligned.h
uaccess.h asm-generic: uaccess: Spelling s/a ny/any/ 2014-01-02 10:45:23 +01:00
unaligned.h asm-generic: allow generic unaligned access if the arch supports it 2014-05-08 10:22:23 +02:00
unistd.h
user.h
vga.h
vmlinux.lds.h kbuild: Fix .text.unlikely placement 2015-08-20 14:55:54 +02:00
vtime.h include/asm-generic/vtime.h: avoid zero-length file 2013-09-30 14:31:02 -07:00
word-at-a-time.h Make asm/word-at-a-time.h available on all architectures 2015-07-08 16:41:55 -04:00
xor.h