[PATCH v5 2/5] powerpc: kretprobes: override default function entry offset

Naveen N. Rao naveen.n.rao at linux.vnet.ibm.com
Wed Mar 8 19:26:07 AEDT 2017


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

Acked-by: Ananth N Mavinakayanahalli <ananth at linux.vnet.ibm.com>
Acked-by: Michael Ellerman <mpe at ellerman.id.au>
Signed-off-by: Naveen N. Rao <naveen.n.rao at linux.vnet.ibm.com>
---
 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)
 {
-- 
2.11.1



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