Commit Graph

12 Commits

Author SHA1 Message Date
Russell King 6020dff092 [ARM] Resolve fuse and direct-IO failures due to missing cache flushes
fuse does not work on ARM due to cache incoherency issues - fuse wants
to use get_user_pages() to copy data from the current process into
kernel space.  However, since this accesses userspace via the kernel
mapping, the kernel mapping can be out of date wrt data written to
userspace.

This can lead to unpredictable behaviour (in the case of fuse) or data
corruption for direct-IO.

This resolves debian bug #402876

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2007-01-08 19:49:58 +00:00
Russell King ad1ae2fe7f [ARM] Unuse another Linux PTE bit
L_PTE_ASID is not really required to be stored in every PTE, since we
can identify it via the address passed to set_pte_at().  So, create
set_pte_ext() which takes the address of the PTE to set, the Linux
PTE value, and the additional CPU PTE bits which aren't encoded in
the Linux PTE value.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-12-13 14:34:43 +00:00
George G. Davis a71ebdfa52 [ARM] 3853/1: Fix flush_ptrace_access() thinko for nonaliasing VIPT cache case
Fix thinko in the flush_ptrace_access() "if (expr)" for the ARM
VIPT non-aliasing cache case.  We only need to flush cache when
VM_EXEC is set in vma->vm_flags but "if (expr) always evaluates
to true on UP systems for the ARM VIPT non-aliasing cache case.

Signed-off-by: George G. Davis <gdavis@mvista.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-09-25 10:34:04 +01:00
Russell King 1b2e2b73b4 [ARM] Cleanup arch/arm/mm a little
Move top_pmd into arch/arm/mm/mm.h - nothing outside arch/arm/mm
references it.

Move the repeated definition of TOP_PTE into mm/mm.h, as well as
a few function prototypes.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-09-20 14:58:35 +01:00
George G. Davis a188ad2bc7 [ARM] 3762/1: Fix ptrace cache coherency bug for ARM1136 VIPT nonaliasing Harvard caches
Patch from George G. Davis

Resolve ARM1136 VIPT non-aliasing cache coherency issues observed when
using ptrace to set breakpoints and cleanup copy_{to,from}_user_page()
while we're here as requested by Russell King because "it's also far
too heavy on non-v6 CPUs".

NOTES:

1. Only access_process_vm() calls copy_{to,from}_user_page().
2. access_process_vm() calls get_user_pages() to pin down the "page".
3. get_user_pages() calls flush_dcache_page(page) which ensures cache
   coherency between kernel and userspace mappings of "page".  However
   flush_dcache_page(page) may not invalidate I-Cache over this range
   for all cases, specifically, I-Cache is not invalidated for the VIPT
   non-aliasing case.  So memory is consistent between kernel and user
   space mappings of "page" but I-Cache may still be hot over this
   range.  IOW, we don't have to worry about flush_cache_page() before
   memcpy().
4. Now, for the copy_to_user_page() case, after memcpy(), we must flush
   the caches so memory is consistent with kernel cache entries and
   invalidate the I-Cache if this mm region is executable.  We don't
   need to do anything after memcpy() for the copy_from_user_page()
   case since kernel cache entries will be invalidated via the same
   process above if we access "page" again.  The flush_ptrace_access()
   function (borrowed from SPARC64 implementation) is added to handle
   cache flushing after memcpy() for the copy_to_user_page() case.

Signed-off-by: George G. Davis <gdavis@mvista.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-09-02 18:43:20 +01:00
Catalin Marinas 141fa40cff [ARM] 3356/1: Workaround for the ARM1136 I-cache invalidation problem
Patch from Catalin Marinas

ARM1136 erratum 371025 (category 2) specifies that, under rare
conditions, an invalidate I-cache by MVA (line or range) operation can
fail to invalidate a cache line. The recommended workaround is to
either invalidate the entire I-cache or invalidate the range by
set/way rather than MVA.

Note that for a 16K cache size, invalidating a 4K page by set/way is
equivalent to invalidating the entire I-cache.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-03-10 22:26:47 +00:00
Russell King df2f5e721e [ARM SMP] Disable lazy flush_dcache_page for SMP
Lazy flush_dcache_page() causes userspace instability on SMP
platforms, so disable it for now.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2005-11-30 16:02:54 +00:00
Catalin Marinas 481467d6fa [ARM] 2939/1: Fix compilation error in arch/arm/mm/flush.c
Patch from Catalin Marinas

When CONFIG_CPU_CACHE_VIPT is defined, the flush_pfn_alias() function is
implicitely declared and it later conflicts with its actual definition.
This patch moves the function definition to the beginning of the file.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2005-09-30 16:07:04 +01:00
Russell King d7b6b35894 [ARM] Fix ARMv6 VIPT cache >= 32K
This adds the necessary changes to ensure that we flush the
caches correctly with aliasing VIPT caches.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2005-09-08 15:32:23 +01:00
Russell King 8830f04a09 [PATCH] ARM: Fix delayed dcache flush for ARMv6 non-aliasing caches
flush_dcache_page() did nothing for these caches, but since they
suffer from I/D cache coherency issues, we need to ensure that data
is written back to RAM.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2005-06-20 09:51:03 +01:00
Russell King 8d802d28c2 [PATCH] ARM: Add V6 aliasing cache flush
Add cache flushing support for aliased V6 caches to
flush_dcache_page.

Signed-off-by: Russell King <rmk@arm.linux.org.uk>
2005-05-10 17:31:43 +01:00
Linus Torvalds 1da177e4c3 Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!
2005-04-16 15:20:36 -07:00