drivers/perf: Prevent forced unbinding of PMU drivers

mainline inclusion
from mainline-v5.8-rc1
commit f32ed8eb
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I4A1WQ
CVE: NA
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=f32ed8eb0e3f0d0ef4ddb854554d60ca5863a9f9



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Forcefully unbinding PMU drivers during perf sampling will lead to
a kernel panic, because the perf upper-layer framework call a NULL
pointer in this situation.

To solve this issue, "suppress_bind_attrs" should be set to true, so
that bind/unbind can be disabled via sysfs and prevent unbinding PMU
drivers during perf sampling.

Signed-off-by: Qi Liu <liuqi115@huawei.com>
Reviewed-by: John Garry <john.garry@huawei.com>
Link: https://lore.kernel.org/r/1594975763-32966-1-git-send-email-liuqi115@huawei.com


Signed-off-by: Will Deacon <will@kernel.org>
Reviewed-by: Yang Jihong <yangjihong1@huawei.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>