[PATCH 1/2] powerpc: kretprobes: override default function entry offset

From: Naveen N. Rao
Date: Thu Feb 16 2017 - 03:19:01 EST


With ABIv2, we offset 8 bytes into a function to get at the local entry
point.

Signed-off-by: Naveen N. Rao <naveen.n.rao@xxxxxxxxxxxxxxxxxx>
---
arch/powerpc/kernel/kprobes.c | 9 +++++++++
1 file changed, 9 insertions(+)

diff --git a/arch/powerpc/kernel/kprobes.c b/arch/powerpc/kernel/kprobes.c
index fce05a38851c..331751701fed 100644
--- a/arch/powerpc/kernel/kprobes.c
+++ b/arch/powerpc/kernel/kprobes.c
@@ -131,6 +131,15 @@ static void __kprobes set_current_kprobe(struct kprobe *p, struct pt_regs *regs,
kcb->kprobe_saved_msr = regs->msr;
}

+bool arch_function_offset_within_entry(unsigned long offset)
+{
+#ifdef PPC64_ELF_ABI_v2
+ return offset <= 8;
+#else
+ return !offset;
+#endif
+}
+
void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri,
struct pt_regs *regs)
{
--
2.11.0