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authorMichael Ellerman <mpe@ellerman.id.au>2015-05-04 16:26:39 +1000
committerIngo Molnar <mingo@kernel.org>2015-05-08 12:26:01 +0200
commitcb307113746b4d184155d2c412e8069aeaa60d42 (patch)
tree6715ef513c6aab176381a36b853f6cfc397ad889 /init
parentff303e66c240ba6269e31817a386995440a18c99 (diff)
downloadlinux-cb307113746b4d184155d2c412e8069aeaa60d42.tar.bz2
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 dc24dec60232..81050e4d9941 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.