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Jiri Olsa authored
If we allocate perf ring buffer with the size of single (user) page, we will get memory corruption when releasing itin rb_free_work function (for CONFIG_PERF_USE_VMALLOC option). For single page sized ring buffer the page_order is -1 (because nr_pages is 0). This needs to be recognized in the rb_free_work function to release proper amount of pages. Adding data_page_nr function that returns number of allocated data pages. Customizing the rest of the code to use it. Reported-by:
Jan Stancek <jstancek@redhat.com> Original-patch-by:
Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by:
Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by:
Jiri Olsa <jolsa@redhat.com> Link: http://lkml.kernel.org/r/20130319143509.GA1128@krava.brq.redhat.comSigned-off-by:
Ingo Molnar <mingo@kernel.org>
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