The help text for this config is duplicated across the x86, parisc, and
s390 Kconfig.debug files. Arnd Bergman noted that the help text was
slightly misleading and should be fixed to state that enabling this
option isn't a problem when using pre 4.4 gcc.
To simplify the rewording, consolidate the text into lib/Kconfig.debug
and modify it there to be more explicit about when you should say N to
this config.
Also, make the text a bit more generic by stating that this option
enables compile time checks so we can cover architectures which emit
warnings vs. ones which emit errors. The details of how an
architecture decided to implement the checks isn't as important as the
concept of compile time checking of copy_from_user() calls.
While we're doing this, remove all the copy_from_user_overflow() code
that's duplicated many times and place it into lib/ so that any
architecture supporting this option can get the function for free.
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Ingo Molnar <mingo@kernel.org>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Acked-by: Helge Deller <deller@gmx.de>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
srmmu_nocache_bitmap is cleared by bit_map_init(). But bit_map_init()
attempts to clear by memset(), so it can't clear the trailing edge of
bitmap properly on big-endian architecture if the number of bits is not
a multiple of BITS_PER_LONG.
Actually, the number of bits in srmmu_nocache_bitmap is not always
a multiple of BITS_PER_LONG. It is calculated as below:
bitmap_bits = srmmu_nocache_size >> SRMMU_NOCACHE_BITMAP_SHIFT;
srmmu_nocache_size is decided proportionally by the amount of system RAM
and it is rounded to a multiple of PAGE_SIZE. SRMMU_NOCACHE_BITMAP_SHIFT
is defined as (PAGE_SHIFT - 4). So it can only be said that bitmap_bits
is a multiple of 16.
This fixes the problem by using bitmap_clear() instead of memset()
in bit_map_init() and this also uses BITS_TO_LONGS() to calculate correct
size at bitmap allocation time.
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: sparclinux@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>
Sparc32 already supported it, as a consequence of using the
generic atomic64 implementation. And the sparc64 implementation
is rather trivial.
This allows us to set ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE for all
of sparc, and avoid the annoying warning from lib/atomic64_test.c
Signed-off-by: David S. Miller <davem@davemloft.net>
This adds optimized memset/bzero/page-clear routines for Niagara-4.
We basically can do what powerpc has been able to do for a decade (via
the "dcbz" instruction), which is use cache line clearing stores for
bzero and memsets with a 'c' argument of zero.
As long as we make the cache initializing store to each 32-byte
subblock of the L2 cache line, it works.
As with other Niagara-4 optimized routines, the key is to make sure to
avoid any usage of the %asi register, as reads and writes to it cost
at least 50 cycles.
For the user clear cases, we don't use these new routines, we use the
Niagara-1 variants instead. Those have to use %asi in an unavoidable
way.
A Niagara-4 8K page clear costs just under 600 cycles.
Add definitions of the MRU variants of the cache initializing store
ASIs. By default, cache initializing stores install the line as Least
Recently Used. If we know we're going to use the data immediately
(which is true for page copies and clears) we can use the Most
Recently Used variant, to decrease the likelyhood of the lines being
evicted before they get used.
Signed-off-by: David S. Miller <davem@davemloft.net>
There's a Niagara 2 memcpy fix in this tree and I have
a Kconfig fix from Dave Jones which requires the sparc-next
changes which went upstream yesterday.
Signed-off-by: David S. Miller <davem@davemloft.net>
It gets clobbered by the kernel's VISEntryHalf, so we have to save it
in a different register than the set clobbered by that macro.
The instance in glibc is OK and doesn't have this problem.
Signed-off-by: David S. Miller <davem@davemloft.net>
To use this, an architecture simply needs to:
1) Provide a user_addr_max() implementation via asm/uaccess.h
2) Add "select GENERIC_STRNCPY_FROM_USER" to their arch Kcnfig
3) Remove the existing strncpy_from_user() implementation and symbol
exports their architecture had.
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: David Howells <dhowells@redhat.com>
Hide details of maximum user address calculation in a new
asm/uaccess.h interface named user_addr_max().
Provide little-endian implementation in find_zero(), which should work
but can probably be improved.
Abstrace alignment check behind IS_UNALIGNED() macro.
Kill double-semicolon, noticed by David Howells.
Signed-off-by: David S. Miller <davem@davemloft.net>
Compute a mask that will only have 0x80 in the bytes which
had a zero in them. The formula is:
~(((x & 0x7f7f7f7f) + 0x7f7f7f7f) | x | 0x7f7f7f7f)
In the inner word iteration, we have to compute the "x | 0x7f7f7f7f"
part, so we can reuse that in the above calculation.
Once we have this mask, we perform divide and conquer to find the
highest 0x80 location.
Signed-off-by: David S. Miller <davem@davemloft.net>
Linus removed the end-of-address-space hackery from
fs/namei.c:do_getname() so we really have to validate these edge
conditions and cannot cheat any more (as x86 used to as well).
Move to a common C implementation like x86 did. And if both
src and dst are sufficiently aligned we'll do word at a time
copies and checks as well.
Signed-off-by: David S. Miller <davem@davemloft.net>
Otherwise if no references exist in the static kernel image,
we won't export the symbol properly to modules.
Signed-off-by: David S. Miller <davem@davemloft.net>
Based on copy from microblaze add ucmpdi2 implementation.
This fixes build of niu driver which failed with:
drivers/built-in.o: In function `niu_get_nfc':
niu.c:(.text+0x91494): undefined reference to `__ucmpdi2'
This driver will never be used on a sparc32 system,
but patch added to fix build breakage with all*config builds.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
For the explicit calls to .udiv/.umul in assembler, I made a
mechanical (read as: safe) transformation. I didn't attempt
to make any simplifications.
In particular, __ndelay and __udelay can be simplified significantly.
Some of the %y reads are unnecessary and these routines have no need
any longer for allocating a register window, they can be leaf
functions.
Signed-off-by: David S. Miller <davem@davemloft.net>
We always have this instruction available, so no need to use
btfixup for it any more.
This also eradicates the whole of atomic_32.S and thus the
__atomic_begin and __atomic_end symbols completely.
Signed-off-by: David S. Miller <davem@davemloft.net>
Both sparc 32-bit's software divide assembler and MPILIB provide
clz_tab[] with identical contents.
Break it out into a seperate object file and select it when
SPARC32 or MPILIB is set.
Reported-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: James Morris <jmorris@namei.org>
