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  1. May 08, 2009
    • Linus Torvalds's avatar
      random: make get_random_int() more random · 8a0a9bd4
      Linus Torvalds authored 
      

It's a really simple patch that basically just open-codes the current
"secure_ip_id()" call, but when open-coding it we now use a _static_
hashing area, so that it gets updated every time.

And to make sure somebody can't just start from the same original seed of
all-zeroes, and then do the "half_md4_transform()" over and over until
they get the same sequence as the kernel has, each iteration also mixes in
the same old "current->pid + jiffies" we used - so we should now have a
regular strong pseudo-number generator, but we also have one that doesn't
have a single seed.

Note: the "pid + jiffies" is just meant to be a tiny tiny bit of noise. It
has no real meaning. It could be anything. I just picked the previous
seed, it's just that now we keep the state in between calls and that will
feed into the next result, and that should make all the difference.

I made that hash be a per-cpu data just to avoid cache-line ping-pong:
having multiple CPU's write to the same data would be fine for randomness,
and add yet another layer of chaos to it, but since get_random_int() is
supposed to be a fast interface I did it that way instead. I considered
using "__raw_get_cpu_var()" to avoid any preemption overhead while still
getting the hash be _mostly_ ping-pong free, but in the end good taste won
out.

Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      8a0a9bd4
    • Linus Torvalds's avatar
      Merge master.kernel.org:/home/rmk/linux-2.6-arm · 2c66fa7e
      Linus Torvalds authored 
      * master.kernel.org:/home/rmk/linux-2.6-arm:
  [ARM] 5507/1: support R_ARM_MOVW_ABS_NC and MOVT_ABS relocation types
  [ARM] 5506/1: davinci: DMA_32BIT_MASK --> DMA_BIT_MASK(32)
  i.MX31: Disable CPU_32v6K in mx3_defconfig.
  mx3fb: Fix compilation with CONFIG_PM
  mx27ads: move PBC mapping out of vmalloc space
  MXC: remove BUG_ON in interrupt handler
  mx31: remove mx31moboard_defconfig
  ARM: ARCH_MXC should select HAVE_CLK
  mxc : BUG in imx_dma_request
  mxc : Clean up properly when imx_dma_free() used without imx_dma_disable()
  [ARM] mv78xx0: update defconfig
  [ARM] orion5x: update defconfig
  [ARM] Kirkwood: update defconfig
  [ARM] Kconfig typo fix:  "PXA930" -> "CPU_PXA930".
  [ARM] S3C2412: Add missing cache flush in suspend code
  [ARM] S3C: Add UDIVSLOT support for newer UARTS
  [ARM] S3C64XX: Add S3C64XX_PA_IIS{0,1} to <mach/map.h>
      2c66fa7e
    • Paul Gortmaker's avatar
      [ARM] 5507/1: support R_ARM_MOVW_ABS_NC and MOVT_ABS relocation types · ae51e609
      Paul Gortmaker authored 
      

From: Bruce Ashfield <bruce.ashfield@windriver.com>

To fully support the armv7-a instruction set/optimizations, support
for the R_ARM_MOVW_ABS_NC and R_ARM_MOVT_ABS relocation types is
required.

The MOVW and MOVT are both load-immediate instructions, MOVW loads 16
bits into the bottom half of a register, and MOVT loads 16 bits into the
top half of a register.

The relocation information for these instructions has a full 32 bit
value, plus an addend which is stored in the 16 immediate bits in the
instruction itself.  The immediate bits in the instruction are not
contiguous (the register # splits it into a 4 bit and 12 bit value),
so the addend has to be extracted accordingly and added to the value.
The value is then split and put into the instruction; a MOVW uses the
bottom 16 bits of the value, and a MOVT uses the top 16 bits.

Signed-off-by: default avatarDavid Borman <david.borman@windriver.com>
Signed-off-by: default avatarBruce Ashfield <bruce.ashfield@windriver.com>
Signed-off-by: default avatarPaul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
      ae51e609
  3. May 07, 2009
  5. May 06, 2009
  7. May 05, 2009