linux.git/arch/arm/mm/alignment.c, branch v3.0

ARM: 6401/1: plug a race in the alignment trap handler

2010-09-23T14:17:04+00:00

When the policy for user space is to ignore misaligned accesses from user
space, the processor then performs a documented rotation on the accessed
data.  This is the result of the access being trapped, and the kernel
disabling the alignment trap before returning to user space again.

In kernel space we always want misaligned accesses to be fixed up.  This
is enforced by always re-enabling the alignment trap on every entry into
kernel space from user space.  No such re-enabling is performed when an
exception occurs while already in kernel space as the alignment trap is
always supposed to be enabled in that case.

There is however a small race window when a misaligned access in user
space is trapped and the alignment trap disabled, but the CPU didn't
return to user space just yet.  Any exception would be entered from kernel
space at that point and the kernel would then execute with the alignment
trap disabled.

Thanks to Maxime Bizon  for providing a test module
that made this issue reproducible.

Signed-off-by: Nicolas Pitre 
Signed-off-by: Russell King

ARM: 6268/1: ARMv6K and ARMv7 use fault statuses 3 and 6 as Access Flag fault

2010-07-27T09:48:41+00:00

Statuses 3 (0b00011) and 6 (0x00110) of DFSR are Access Flags faults on
ARMv6K and ARMv7. Let's patch fsr_info[] at runtime if we are on ARMv7
or later.

Unfortunately, we don't have runtime check for 'K' extension, so we
can't check for it.

Signed-off-by: Kirill A. Shutemov 
Signed-off-by: Russell King

ARM: 6269/1: Add 'code' parameter for hook_fault_code()

2010-07-27T09:48:34+00:00

Add one more parameter to hook_fault_code() to be able to set 'code'
field of struct fsr_info.

Signed-off-by: Kirill A. Shutemov 
Signed-off-by: Russell King

ARM: 6252/1: Use SIGBUS for unaligned access instead of SIGILL

2010-07-27T09:43:49+00:00

POSIX specify to use signal SIGBUS with code BUS_ADRALN for invalid
address alignment.

Signed-off-by: Kirill A. Shutemov 
Signed-off-by: Russell King

Merge branch 'devel-stable' into devel

2010-05-17T16:24:04+00:00

Conflicts:
	arch/arm/Kconfig
	arch/arm/include/asm/system.h
	arch/arm/mm/Kconfig

ARM: convert /proc/cpu/aligment to seq_file

2010-05-15T14:03:48+00:00

Convert code away from ->read_proc/->write_proc interfaces.  Switch to
proc_create()/proc_create_data() which makes addition of proc entries
reliable wrt NULL ->proc_fops, NULL ->data and so on.

Problem with ->read_proc et al is described here commit
786d7e1612f0b0adb6046f19b906609e4fe8b1ba "Fix rmmod/read/write races in
/proc entries"

This patch is part of an effort to remove the old simple procfs PAGE_SIZE
buffer interface.

Signed-off-by: Alexey Dobriyan 
Signed-off-by: Andrew Morton 
Signed-off-by: Russell King

ARM: fix build error in arch/arm/kernel/process.c

2010-04-21T07:45:21+00:00

/tmp/ccJ3ssZW.s: Assembler messages:
/tmp/ccJ3ssZW.s:1952: Error: can't resolve `.text' {.text section} - `.LFB1077'

This is caused because:

	.section .data
	.section .text
	.section .text
	.previous

does not return us to the .text section, but the .data section; this
makes use of .previous dangerous if the ordering of previous sections
is not known.

Fix up the other users of .previous; .pushsection and .popsection are
a safer pairing to use than .section and .previous.

Signed-off-by: Russell King

Merge branch 'for-linus' of master.kernel.org:/home/rmk/linux-2.6-arm

2010-03-01T17:15:15+00:00

* 'for-linus' of master.kernel.org:/home/rmk/linux-2.6-arm: (100 commits)
  ARM: Eliminate decompressor -Dstatic= PIC hack
  ARM: 5958/1: ARM: U300: fix inverted clk round rate
  ARM: 5956/1: misplaced parentheses
  ARM: 5955/1: ep93xx: move timer defines into core.c and document
  ARM: 5954/1: ep93xx: move gpio interrupt support to gpio.c
  ARM: 5953/1: ep93xx: fix broken build of clock.c
  ARM: 5952/1: ARM: MM: Add ARM_L1_CACHE_SHIFT_6 for handle inside each ARCH Kconfig
  ARM: 5949/1: NUC900 add gpio virtual memory map
  ARM: 5948/1: Enable timer0 to time4 clock support for nuc910
  ARM: 5940/2: ARM: MMCI: remove custom DBG macro and printk
  ARM: make_coherent(): fix problems with highpte, part 2
  MM: Pass a PTE pointer to update_mmu_cache() rather than the PTE itself
  ARM: 5945/1: ep93xx: include correct irq.h in core.c
  ARM: 5933/1: amba-pl011: support hardware flow control
  ARM: 5930/1: Add PKMAP area description to memory.txt.
  ARM: 5929/1: Add checks to detect overlap of memory regions.
  ARM: 5928/1: Change type of VMALLOC_END to unsigned long.
  ARM: 5927/1: Make delimiters of DMA area globally visibly.
  ARM: 5926/1: Add "Virtual kernel memory..." printout.
  ARM: 5920/1: OMAP4: Enable L2 Cache
  ...

Fix up trivial conflict in arch/arm/mach-mx25/clock.c

ARM: allow alignment fault mode to be configured at kernel boot

2010-02-20T16:20:49+00:00

Some glibc versions intentionally create lots of alignment faults in
their gconv code, which if not fixed up, results in segfaults during
boot.  This can prevent systems booting properly.

There is no clear hard-configurable default for this; the desired
default depends on the nature of the userspace which is going to be
booted.

So, provide a way for the alignment fault handler to be configured via
the kernel command line.

Signed-off-by: Russell King

ARM: Move creation of /proc/cpu out of alignment.c

2010-02-15T21:39:12+00:00

Always creating this directory avoids other users having to jump
through silly hoops when they want to share this directory.

Signed-off-by: Russell King