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authorMichael Ellerman <mpe@ellerman.id.au>2015-05-04 06:26:39 (GMT)
committerIngo Molnar <mingo@kernel.org>2015-05-08 10:26:01 (GMT)
commitcb307113746b4d184155d2c412e8069aeaa60d42 (patch)
tree6715ef513c6aab176381a36b853f6cfc397ad889 /init
parentff303e66c240ba6269e31817a386995440a18c99 (diff)
downloadlinux-cb307113746b4d184155d2c412e8069aeaa60d42.tar.xz
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>
Diffstat (limited to 'init')
-rw-r--r--init/Kconfig2
1 files changed, 1 insertions, 1 deletions
diff --git a/init/Kconfig b/init/Kconfig
index dc24dec..81050e4 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -1637,7 +1637,7 @@ config PERF_EVENTS
config DEBUG_PERF_USE_VMALLOC
default n
bool "Debug: use vmalloc to back perf mmap() buffers"
- depends on PERF_EVENTS && DEBUG_KERNEL
+ depends on PERF_EVENTS && DEBUG_KERNEL && !PPC
select PERF_USE_VMALLOC
help
Use vmalloc memory to back perf mmap() buffers.