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Commit b3f20785 authored by Pawel Moll's avatar Pawel Moll Committed by Ingo Molnar
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perf: Handle compat ioctl



When running a 32-bit userspace on a 64-bit kernel (eg. i386
application on x86_64 kernel or 32-bit arm userspace on arm64
kernel) some of the perf ioctls must be treated with special
care, as they have a pointer size encoded in the command.

For example, PERF_EVENT_IOC_ID in 32-bit world will be encoded
as 0x80042407, but 64-bit kernel will expect 0x80082407. In
result the ioctl will fail returning -ENOTTY.

This patch solves the problem by adding code fixing up the
size as compat_ioctl file operation.

Reported-by: default avatarDrew Richardson <drew.richardson@arm.com>
Signed-off-by: default avatarPawel Moll <pawel.moll@arm.com>
Signed-off-by: default avatarPeter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lkml.kernel.org/r/1402671812-9078-1-git-send-email-pawel.moll@arm.com


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent f96f5678
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