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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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| .. | ||
| abort-ev4.S | ||
| abort-ev4t.S | ||
| abort-ev5t.S | ||
| abort-ev5tj.S | ||
| abort-ev6.S | ||
| abort-lv4t.S | ||
| abort-macro.S | ||
| alignment.c | ||
| cache-v3.S | ||
| cache-v4.S | ||
| cache-v4wb.S | ||
| cache-v4wt.S | ||
| cache-v6.S | ||
| consistent.c | ||
| copypage-v3.S | ||
| copypage-v4mc.c | ||
| copypage-v4wb.S | ||
| copypage-v4wt.S | ||
| copypage-v6.c | ||
| copypage-xsc3.S | ||
| copypage-xscale.c | ||
| discontig.c | ||
| extable.c | ||
| fault-armv.c | ||
| fault.c | ||
| fault.h | ||
| flush.c | ||
| init.c | ||
| iomap.c | ||
| ioremap.c | ||
| Kconfig | ||
| Makefile | ||
| mm-armv.c | ||
| mmap.c | ||
| mmu.c | ||
| nommu.c | ||
| proc-arm6_7.S | ||
| proc-arm720.S | ||
| proc-arm920.S | ||
| proc-arm922.S | ||
| proc-arm925.S | ||
| proc-arm926.S | ||
| proc-arm1020.S | ||
| proc-arm1020e.S | ||
| proc-arm1022.S | ||
| proc-arm1026.S | ||
| proc-macros.S | ||
| proc-sa110.S | ||
| proc-sa1100.S | ||
| proc-syms.c | ||
| proc-v6.S | ||
| proc-xsc3.S | ||
| proc-xscale.S | ||
| tlb-v3.S | ||
| tlb-v4.S | ||
| tlb-v4wb.S | ||
| tlb-v4wbi.S | ||
| tlb-v6.S | ||