perf_event: Don't allow vmalloc() backed perf on powerpc
authorMichael Ellerman <mpe@ellerman.id.au>
Mon, 4 May 2015 06:26:39 +0000 (16:26 +1000)
committerIngo Molnar <mingo@kernel.org>
Fri, 8 May 2015 10:26:01 +0000 (12:26 +0200)
commitcb307113746b4d184155d2c412e8069aeaa60d42
tree6715ef513c6aab176381a36b853f6cfc397ad889
parentff303e66c240ba6269e31817a386995440a18c99
perf_event: Don't allow vmalloc() backed perf on powerpc

On powerpc the perf event interrupt is not masked when interrupts are
disabled, allowing it to function as an NMI.

This causes problems if perf is using vmalloc. If we take a page fault
on the vmalloc region the fault handler will fail the page fault because
it detects we are coming in from an NMI (see do_hash_page()).

We don't actually need or want vmalloc backed perf so just disable it on
powerpc.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: <linuxppc-dev@ozlabs.org>
Cc: Andrew Morton <akpm@osdl.org>
Cc: Anton Blanchard <anton@samba.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: acme@ghostprotocols.net
Cc: sukadev@linux.vnet.ibm.com
Link: http://lkml.kernel.org/r/1430720799-18426-1-git-send-email-mpe@ellerman.id.au
Signed-off-by: Ingo Molnar <mingo@kernel.org>
init/Kconfig