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
The c6x clkdev.h header is the same as the asm-generic header, so
just use the asm-generic one.
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Mark Salter <msalter@redhat.com>
Commit 2ae416b142 ("mm: new mm hook framework") introduced an empty
header file (mm-arch-hooks.h) for every architecture, even those which
doesn't need to define mm hooks.
As suggested by Geert Uytterhoeven, this could be cleaned through the use
of a generic header file included via each per architecture
asm/include/Kbuild file.
The PowerPC architecture is not impacted here since this architecture has
to defined the arch_remap MM hook.
Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
Suggested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Added the x86 implementation of word-at-a-time to the
generic version, which previously only supported big-endian.
Omitted the x86-specific load_unaligned_zeropad(), which in
any case is also not present for the existing BE-only
implementation of a word-at-a-time, and is only used under
CONFIG_DCACHE_WORD_ACCESS.
Added as a "generic-y" to the Kbuilds of all architectures
that didn't previously have it.
Signed-off-by: Chris Metcalf <cmetcalf@ezchip.com>
Or it will cause building break with allmodconfig:
CC [M] drivers/tty/serial/8250/8250_core.o
drivers/tty/serial/8250/8250_core.c:102:24: fatal error: asm/serial.h: No such file or directory
Signed-off-by: Chen Gang <gang.chen.5i5j@gmail.com>
Signed-off-by: Mark Salter <msalter@redhat.com>
As there are now no remaining users of arch_fast_hash(), lets kill
it entirely.
This basically reverts commit 71ae8aac3e ("lib: introduce arch
optimized hash library") and follow-up work, that is f.e., commit
237217546d ("lib: hash: follow-up fixups for arch hash"),
commit e3fec2f74f ("lib: Add missing arch generic-y entries for
asm-generic/hash.h") and last but not least commit 6a02652df5
("perf tools: Fix include for non x86 architectures").
Cc: Francesco Fusco <fusco@ntop.org>
Cc: Thomas Graf <tgraf@suug.ch>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The nohz full code needs irq work to trigger its own interrupt so that
the subsystem can work even when the tick is stopped.
Lets introduce arch_irq_work_has_interrupt() that archs can override to
tell about their support for this ability.
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Pull asm-generic cleanup from Arnd Bergmann:
"These are a few cleanups for asm-generic:
- a set of patches from Lars-Peter Clausen to generalize asm/mmu.h
and use it in the architectures that don't need any special
handling.
- A patch from Will Deacon to remove the {read,write}s{b,w,l} as
discussed during the arm64 review
- A patch from James Hogan that helps with the meta architecture
series."
* tag 'asm-generic' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic:
xtensa: Use generic asm/mmu.h for nommu
h8300: Use generic asm/mmu.h
c6x: Use generic asm/mmu.h
asm-generic/mmu.h: Add support for FDPIC
asm-generic/mmu.h: Remove unused vmlist field from mm_context_t
asm-generic: io: remove {read,write} string functions
asm-generic/io.h: remove asm/cacheflush.h include
c6x's asm/mmu.h is basically identical to asm-generic/mmu.h, so use it instead
of the custom version.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Acked-by: Mark Salter <msalter@redhat.com>
Tested-by: Mark Salter <msalter@redhat.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
In order to promote interoperability between userspace tracers and ftrace,
add a trace_clock that reports raw TSC values which will then be recorded
in the ring buffer. Userspace tracers that also record TSCs are then on
exactly the same time base as the kernel and events can be unambiguously
interlaced.
Tested: Enabled a tracepoint and the "tsc" trace_clock and saw very large
timestamp values.
v2:
Move arch-specific bits out of generic code.
v3:
Rename "x86-tsc", cleanups
v7:
Generic arch bits in Kbuild.
Google-Bug-Id: 6980623
Link: http://lkml.kernel.org/r/1352837903-32191-1-git-send-email-dhsharp@google.com
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@linux.intel.com>
Signed-off-by: David Sharp <dhsharp@google.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Pull C6X UAPI disintegration from Mark Salter:
- scripted UAPI disintegration by David Howells.
* tag 'for-linus' of git://linux-c6x.org/git/projects/linux-c6x-upstreaming:
UAPI: (Scripted) Disintegrate arch/c6x/include/asm
Pull generic execve() changes from Al Viro:
"This introduces the generic kernel_thread() and kernel_execve()
functions, and switches x86, arm, alpha, um and s390 over to them."
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal: (26 commits)
s390: convert to generic kernel_execve()
s390: switch to generic kernel_thread()
s390: fold kernel_thread_helper() into ret_from_fork()
s390: fold execve_tail() into start_thread(), convert to generic sys_execve()
um: switch to generic kernel_thread()
x86, um/x86: switch to generic sys_execve and kernel_execve
x86: split ret_from_fork
alpha: introduce ret_from_kernel_execve(), switch to generic kernel_execve()
alpha: switch to generic kernel_thread()
alpha: switch to generic sys_execve()
arm: get rid of execve wrapper, switch to generic execve() implementation
arm: optimized current_pt_regs()
arm: introduce ret_from_kernel_execve(), switch to generic kernel_execve()
arm: split ret_from_fork, simplify kernel_thread() [based on patch by rmk]
generic sys_execve()
generic kernel_execve()
new helper: current_pt_regs()
preparation for generic kernel_thread()
um: kill thread->forking
um: let signal_delivered() do SIGTRAP on singlestepping into handler
...
The c6x signal.h includes the asm-generic version and provides
a couple of extern declarations. David Howells pointed out that
the externs needed to be protected by ifdef __KERNEL__. As it
turns out, the externs aren't really needed since the functions
are only called from asm code. So this patch gets rid of the
c6x signal.h and uses just the asm-generic version.
Signed-off-by: Mark Salter <msalter@redhat.com>
A recent patch in the linux-next tree caused a build failure on
C6X because C6X didn't define a read_barrier_depends() macro. C6X
does not support SMP and the architecture doesn't provide any
special memory ordering instructions, so it makes sense to just
use the generic barrier.h rather than patching the existing c6x
specific header.
Signed-off-by: Mark Salter <msalter@redhat.com>
