linux/arch
Linus Torvalds 92ae03f2ef x86: merge 32/64-bit versions of 'strncpy_from_user()' and speed it up
This merges the 32- and 64-bit versions of the x86 strncpy_from_user()
by just rewriting it in C rather than the ancient inline asm versions
that used lodsb/stosb and had been duplicated for (trivial) differences
between the 32-bit and 64-bit versions.

While doing that, it also speeds them up by doing the accesses a word at
a time.  Finally, the new routines also properly handle the case of
hitting the end of the address space, which we have never done correctly
before (fs/namei.c has a hack around it for that reason).

Despite all these improvements, it actually removes more lines than it
adds, due to the de-duplication.  Also, we no longer export (or define)
the legacy __strncpy_from_user() function (that was defined to not do
the user permission checks), since it's not actually used anywhere, and
the user address space checks are built in to the new code.

Other architecture maintainers have been notified that the old hack in
fs/namei.c will be going away in the 3.5 merge window, in case they
copied the x86 approach of being a bit cavalier about the end of the
address space.

Cc: linux-arch@vger.kernel.org
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Anvin" <hpa@zytor.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-04-11 09:41:28 -07:00
..
alpha Merge branch 'akpm' (Andrew's patch-bomb) 2012-04-05 15:30:34 -07:00
arm ARM: SoC fixes for 3.4-rc2 2012-04-05 22:13:39 -07:00
avr32 avr32: fix nop compile fails from system.h split up 2012-04-04 08:23:44 -07:00
blackfin blackfin: update defconfig for bf527-ezkit 2012-04-06 10:25:03 +08:00
c6x Merge branch 'akpm' (Andrew's patch-bomb) 2012-04-05 15:30:34 -07:00
cris Merge branch 'x86-x32-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2012-03-29 18:12:23 -07:00
frv frv: fix warnings in mb93090-mb00/pci-dma.c about implicit EXPORT_SYMBOL 2012-04-02 14:41:26 -07:00
h8300 Merge branch 'x86-x32-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2012-03-29 18:12:23 -07:00
hexagon Merge branch 'for-linus' of git://git.linaro.org/people/mszyprowski/linux-dma-mapping 2012-04-04 17:13:43 -07:00
ia64 Merge branch 'for-linus' of git://git.linaro.org/people/mszyprowski/linux-dma-mapping 2012-04-04 17:13:43 -07:00
m32r Merge branch 'x86-x32-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2012-03-29 18:12:23 -07:00
m68k m68k/q40: Add missing platform check before registering platform devices 2012-04-01 22:57:53 +02:00
microblaze Merge branch 'for-linus' of git://git.linaro.org/people/mszyprowski/linux-dma-mapping 2012-04-04 17:13:43 -07:00
mips Merge branch 'for-linus' of git://git.linaro.org/people/mszyprowski/linux-dma-mapping 2012-04-04 17:13:43 -07:00
mn10300 Merge branch 'x86-x32-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2012-03-29 18:12:23 -07:00
openrisc Disintegrate and delete asm/system.h 2012-03-28 15:58:21 -07:00
parisc parisc: fix missing cmpxchg file error from system.h split 2012-04-02 14:41:26 -07:00
powerpc Merge branch 'kvm-updates/3.4' of git://git.kernel.org/pub/scm/virt/kvm/kvm 2012-04-07 09:53:33 -07:00
s390 [S390] Fix build errors (fallout from system.h disintegration) 2012-03-30 09:41:12 +02:00
score Delete all instances of asm/system.h 2012-03-28 18:30:03 +01:00
sh SuperH updates for 3.4-rc1 2012-04-07 09:52:46 -07:00
sparc Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc 2012-04-10 10:28:26 -07:00
tile Merge branch 'stable' of git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile 2012-04-06 17:56:20 -07:00
um um: uml_setup_stubs': warning: unused variable 'pages' 2012-04-10 00:13:45 +02:00
unicore32 Merge branch 'for-linus' of git://git.linaro.org/people/mszyprowski/linux-dma-mapping 2012-04-04 17:13:43 -07:00
x86 x86: merge 32/64-bit versions of 'strncpy_from_user()' and speed it up 2012-04-11 09:41:28 -07:00
xtensa Merge branch 'x86-x32-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2012-03-29 18:12:23 -07:00
.gitignore
Kconfig Merge git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile 2012-03-29 14:49:45 -07:00