We will need to patch several instruction streams over to a different
code path, so we need a way to patch a single instruction with a branch
somewhere else.
This patch adds a helper to facilitate this patching.
Signed-off-by: Alexander Graf <ag...@suse.de>
---
v2 -> v3:
- add safety check for relocatable kernels
---
arch/powerpc/kernel/kvm.c | 14 ++++++++++++++
1 files changed, 14 insertions(+), 0 deletions(-)
diff --git a/arch/powerpc/kernel/kvm.c b/arch/powerpc/kernel/kvm.c
index 926f93f..239a70d 100644
--- a/arch/powerpc/kernel/kvm.c
+++ b/arch/powerpc/kernel/kvm.c
@@ -107,6 +107,20 @@ static void kvm_patch_ins_nop(u32 *inst)
kvm_patch_ins(inst, KVM_INST_NOP);
}
+static void kvm_patch_ins_b(u32 *inst, int addr)
+{
+#ifdef CONFIG_RELOCATABLE
+ /* On relocatable kernels interrupts handlers and our code
+ can be in different regions, so we don't patch them */
+
+ extern u32 __end_interrupts;
+ if ((ulong)inst < (ulong)&__end_interrupts)
+ return;
+#endif
+
+ kvm_patch_ins(inst, KVM_INST_B | (addr & KVM_INST_B_MASK));
+}
+
static u32 *kvm_alloc(int len)
{
u32 *p;
--
1.6.0.2
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