microblaze: Unprivileged stream instruction awareness
Add cpuinfo support for the new MicroBlaze option permitting userspace
(unprivileged) access to the streaming instructions (FSL / AXI-stream).
Emit a noisy warning at bootup if this is enabled, because bad user code
can potentially lockup the CPU.
Signed-off-by: John A. Williams <john.williams@petalogix.com>
Signed-off-by: Michal Simek <monstr@monstr.eu>
diff --git a/arch/microblaze/kernel/cpu/cpuinfo.c b/arch/microblaze/kernel/cpu/cpuinfo.c
index c1640c5..44394d8 100644
--- a/arch/microblaze/kernel/cpu/cpuinfo.c
+++ b/arch/microblaze/kernel/cpu/cpuinfo.c
@@ -88,4 +88,8 @@
printk(KERN_WARNING "%s: Unsupported PVR setting\n", __func__);
set_cpuinfo_static(&cpuinfo, cpu);
}
+
+ if (cpuinfo.mmu_privins)
+ printk(KERN_WARNING "%s: Stream instructions enabled"
+ " - USERSPACE CAN LOCK THIS KERNEL!\n", __func__);
}