On Wed, Jun 06, 2018 at 03:54:11PM +0300, Adrian Hunter wrote: > Without program headers for PTI entry trampoline pages, the trampoline > virtual addresses do not map to anything. >
> > In addition, entry trampolines all map to the same page. Represent that by > giving the corresponding program headers in kcore the same offset. > > This has the benefit that, when perf tools uses /proc/kcore as a source for > kernel object code, samples from different CPU trampolines are aggregated > together. Note, such aggregation is normal for profiling i.e. people want > to profile the object code, not every different virtual address the object > code might be mapped to (across different processes for example). > > Signed-off-by: Adrian Hunter <[email protected]> > Acked-by: Andi Kleen <[email protected]> > --- > arch/x86/mm/cpu_entry_area.c | 10 ++++++++++ > fs/proc/kcore.c | 7 +++++-- > include/linux/kcore.h | 13 +++++++++++++ > 3 files changed, 28 insertions(+), 2 deletions(-) This also adds the KCORE_REMAP functionality, but isn't mentioned at all in the Changelog. Still, looks OK I suppose, Acked-by: Peter Zijlstra (Intel) <[email protected]>
