forked from Minki/linux
a188ad2bc7
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>
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| .. | ||
| boot | ||
| common | ||
| configs | ||
| kernel | ||
| lib | ||
| mach-aaec2000 | ||
| mach-at91rm9200 | ||
| mach-clps711x | ||
| mach-clps7500 | ||
| mach-ebsa110 | ||
| mach-ep93xx | ||
| mach-footbridge | ||
| mach-h720x | ||
| mach-imx | ||
| mach-integrator | ||
| mach-iop3xx | ||
| mach-ixp4xx | ||
| mach-ixp23xx | ||
| mach-ixp2000 | ||
| mach-l7200 | ||
| mach-lh7a40x | ||
| mach-netx | ||
| mach-omap1 | ||
| mach-omap2 | ||
| mach-pnx4008 | ||
| mach-pxa | ||
| mach-realview | ||
| mach-rpc | ||
| mach-s3c2410 | ||
| mach-sa1100 | ||
| mach-shark | ||
| mach-versatile | ||
| mm | ||
| nwfpe | ||
| oprofile | ||
| plat-omap | ||
| tools | ||
| vfp | ||
| Kconfig | ||
| Kconfig-nommu | ||
| Kconfig.debug | ||
| Makefile | ||