Oleg Nesterov 5323ce71e4 uprobes: Write_opcode()->__replace_page() can race with try_to_unmap() ... write_opcode() gets old_page via get_user_pages() and then calls __replace_page() which assumes that this old_page is still mapped after pte_offset_map_lock(). This is not true if this old_page was already try_to_unmap()'ed, and in this case everything __replace_page() does with old_page is wrong. Just for example, put_page() is not balanced. I think it is possible to teach __replace_page() to handle this unlikely case correctly, but this patch simply changes it to use page_check_address() and return -EAGAIN if it fails. The caller should notice this error code and retry. Note: write_opcode() asks for the cleanups, I'll try to do this in a separate patch. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Anton Arapov <anton@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20120615154328.GA9571@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>		2012-06-16 09:10:42 +02:00
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callchain.c	perf: Don't call release_callchain_buffers() if allocation fails	2012-01-21 09:33:41 +01:00
core.c	perf: Remove duplicate invocation on perf_event_for_each	2012-05-31 14:01:00 -03:00
hw_breakpoint.c	Merge branch 'x86/cleanups' into perf/uprobes	2012-03-13 16:33:03 +01:00
internal.h	Merge branch 'perf/urgent' into perf/core	2011-12-06 06:43:49 +01:00
Makefile	uprobes: Move to kernel/events/	2012-02-22 11:08:00 +01:00
ring_buffer.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial	2012-01-08 13:21:22 -08:00
uprobes.c	uprobes: Write_opcode()->__replace_page() can race with try_to_unmap()	2012-06-16 09:10:42 +02:00