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
arch: Mass conversion of smp_mb__*()
2014-04-18 14:20:48 +02:00
mm, asm-generic: define PUD_SHIFT in <asm-generic/4level-fixup.h>
2015-02-11 17:06:03 -08:00
asm-generic: Add common asm-offsets.h
2015-06-23 13:35:49 +09:00
locking, asm-generic: Add _{relaxed|acquire|release}() variants for 'atomic_long_t'
2015-08-12 11:59:01 +02:00
atomic: Collapse all atomic_{set,clear}_mask definitions
2015-07-27 14:06:24 +02:00
atomic: Provide atomic_{or,xor,and}
2015-07-27 14:06:24 +02:00
audit: Modify a set of system calls in audit class definitions
2014-01-17 17:01:46 -05:00
audit: Modify a set of system calls in audit class definitions
2014-01-17 17:01:46 -05:00
locking, arch: use WRITE_ONCE()/READ_ONCE() in smp_store_release()/smp_load_acquire()
2015-08-03 10:59:30 +02:00
arch: Prepare for smp_mb__{before,after}_atomic()
2014-04-18 11:40:30 +02:00
bug: Make BUG() always stop the machine
2014-04-07 16:36:10 -07:00
asm-generic headers: Allow yet more arch overrides in checksum.h
2013-02-11 20:00:33 +05:30
asm-generic: COMMON_CLK defines __clk_{get,put}
2014-09-25 18:00:45 -07:00
LLVMLinux: Remove warning about returning an uninitialized variable
2014-04-09 13:44:35 -07:00
locking/rtmutex: Drop usage of __HAVE_ARCH_CMPXCHG
2015-05-13 10:51:28 +02:00
cputime: Generic on-demand virtual cputime accounting
2013-01-27 19:23:27 +01:00
sched, time: Fix build error with 64 bit cputime_t on 32 bit systems
2014-10-03 05:46:55 +02:00
sched, time: Fix build error with 64 bit cputime_t on 32 bit systems
2014-10-03 05:46:55 +02:00
DMA-API: Change dma_declare_coherent_memory() CPU address to phys_addr_t
2014-05-20 16:55:23 -06:00
asm-generic: Add dma-contiguous.h
2014-09-22 13:35:51 +02:00
dma-mapping: consolidate dma_set_mask
2015-09-10 13:29:01 -07:00
Merge branch 'akpm' (patches from Andrew)
2015-09-08 17:52:23 -07:00
mm: provide early_memremap_ro to establish read-only mapping
2015-08-20 12:24:22 +01:00
sched/preempt, futex: Disable preemption in UP futex_atomic_cmpxchg_inatomic() explicitly
2015-05-19 08:39:16 +02:00
gpio: remove gpiod_sysfs_set_active_low
2015-05-12 10:46:53 +02:00
mm: Fix generic hugetlb pte check return type.
2013-10-02 20:02:35 -04:00
readq/writeq: Add explicit lo_hi_[read|write]_q and hi_lo_[read|write]_q
2014-07-04 13:27:30 +02:00
readq/writeq: Add explicit lo_hi_[read|write]_q and hi_lo_[read|write]_q
2014-07-04 13:27:30 +02:00
x86/mm, asm-generic: Add IOMMU ioremap_uc() variant default
2015-07-21 10:47:03 +02:00
include/asm-generic/ioctl.h: fix _IOC_TYPECHECK sparse error
2014-06-06 16:08:13 -07:00
x86/mm, asm-generic: Add ioremap_wt() for creating Write-Through mappings
2015-06-07 15:28:56 +02:00
irq_work: Introduce arch_irq_work_has_interrupt()
2014-09-13 18:38:07 +02:00
KVM: add kvm_para_available to asm-generic/kvm_para.h
2013-06-05 13:21:29 +03:00
locking/mcs: Allow architecture specific asm files to be used for contended case
2014-02-09 21:18:52 +01:00
mm: fix type cast in __pfn_to_phys()
2015-09-19 03:58:10 -04:00
mm: clean up per architecture MM hook header files
2015-07-17 16:39:53 -07:00
mm: Make arch_unmap()/bprm_mm_init() available to all architectures
2014-11-19 11:54:13 +01:00
asm-generic: Remove asm-generic arch_bprm_mm_init()
2014-11-22 21:52:08 +01:00
asm-generic: Add msi.h
2014-11-23 13:01:47 +01:00
arch: Make __mutex_fastpath_lock_retval return whether fastpath succeeded or not
2013-06-26 12:10:55 +02:00
arch: Make __mutex_fastpath_lock_retval return whether fastpath succeeded or not
2013-06-26 12:10:55 +02:00
arch: Make __mutex_fastpath_lock_retval return whether fastpath succeeded or not
2013-06-26 12:10:55 +02:00
pci-dma-compat: add pci_zalloc_consistent helper
2014-08-08 15:57:28 -07:00
PCI: Remove unused pcibios_select_root() (again)
2015-06-08 07:56:21 -05:00
PCI: Add pci_iomap_wc() variants
2015-08-25 09:59:45 +02:00
percpu: preffity percpu header files
2014-06-17 19:12:40 -04:00
mm: clarify that the function operates on hugepage pte
2015-06-24 17:49:44 -07:00
sched/preempt: Fix cond_resched_lock() and cond_resched_softirq()
2015-08-03 12:21:24 +02:00
locking/qrwlock: Make use of _{acquire|release|relaxed}() atomics
2015-08-12 11:59:06 +02:00
locking/rwlocks: Introduce 'qrwlocks' - fair, queued rwlocks
2014-06-06 07:58:28 +02:00
locking/qspinlock/x86: Fix performance regression under unaccelerated VMs
2015-09-11 07:49:42 +02:00
locking/qspinlock: Optimize for smaller NR_CPUS
2015-05-08 12:36:48 +02:00
asm-generic: remove _STK_LIM_MAX
2014-05-15 00:32:09 +01:00
rtc: cmos: century support
2015-09-05 13:19:09 +02:00
asm-generic: rwsem: de-PPCify rwsem.h
2014-03-14 18:02:08 +00:00
seccomp: allow COMPAT sigreturn overrides
2015-04-17 09:04:09 -04:00
nosave: consolidate __nosave_{begin,end} in <asm/sections.h>
2014-10-09 22:26:04 -04:00
constify copy_siginfo_to_user{,32}()
2013-11-09 00:16:29 -05:00
crypto: create generic version of ablk_helper
2013-09-24 06:02:24 +10:00
syscall.h: fix doc text for syscall_get_arch()
2014-09-23 16:20:00 -04:00
burying unused conditionals
2013-02-14 09:21:15 -05:00
mm: mmu_gather: use tlb->end != 0 only for TLB invalidation
2015-01-13 15:20:40 +13:00
asm-generic: uaccess: Spelling s/a ny/any/
2014-01-02 10:45:23 +01:00
asm-generic: allow generic unaligned access if the arch supports it
2014-05-08 10:22:23 +02:00
We get rid of the general module prefix confusion with a binary config option,
2013-05-05 10:58:06 -07:00
kbuild: Fix .text.unlikely placement
2015-08-20 14:55:54 +02:00
include/asm-generic/vtime.h: avoid zero-length file
2013-09-30 14:31:02 -07:00
Make asm/word-at-a-time.h available on all architectures
2015-07-08 16:41:55 -04:00
30c44659f4