powerpc/perf: Fix MMCR2 handling for EBB

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In the recent commit b50a6c584b "Clear MMCR2 when enabling PMU", I
screwed up the handling of MMCR2 for tasks using EBB.

We must make sure we set MMCR2 *before* ebb_switch_in(), otherwise we
overwrite the value of MMCR2 that userspace may have written. That
potentially breaks a task that uses EBB and manually uses MMCR2 for
event freezing.

Fixes: b50a6c584b ("powerpc/perf: Clear MMCR2 when enabling PMU")
Cc: stable@vger.kernel.org
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

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Michael Ellerman 2014-07-23 17:20:04 +10:00 • committed by Benjamin Herrenschmidt

parent 6f5405bc2e

commit 8903461c9b

1 changed files with 3 additions and 3 deletions

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arch/powerpc/perf/core-book3s.c

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