linux/kernel/events
Srikar Dronamraju d4b3b6384f uprobes/core: Allocate XOL slots for uprobes use
Uprobes executes the original instruction at a probed location
out of line. For this, we allocate a page (per mm) upon the
first uprobe hit, in the process user address space, divide it
into slots that are used to store the actual instructions to be
singlestepped. These slots are known as xol (execution out of
line) slots.

Care is taken to ensure that the allocation is in an unmapped
area as close to the top of the user address space as possible,
with appropriate permission settings to keep selinux like
frameworks happy.

Upon a uprobe hit, a free slot is acquired, and is released
after the singlestep completes.

Lots of improvements courtesy suggestions/inputs from Peter and
Oleg.

[ Folded a fix for build issue on powerpc fixed and reported by
  Stephen Rothwell. ]

Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Jim Keniston <jkenisto@linux.vnet.ibm.com>
Cc: Linux-mm <linux-mm@kvack.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Anton Arapov <anton@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20120330182631.10018.48175.sendpatchset@srdronam.in.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-03-31 11:50:01 +02:00
..
callchain.c perf: Don't call release_callchain_buffers() if allocation fails 2012-01-21 09:33:41 +01:00
core.c Merge branch 'x86/cleanups' into perf/uprobes 2012-03-13 16:33:03 +01:00
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/core: Allocate XOL slots for uprobes use 2012-03-31 11:50:01 +02:00