From: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Date: Wed, 8 Mar 2017 08:26:07 +0000 (+0530)
Subject: powerpc/kretprobes: Override default function entry offset
X-Git-Tag: v4.12-rc1~17^2~57^2~6
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=a64e3f35a45f4a84148d0ba30a3c75c4c7076928;p=platform%2Fkernel%2Flinux-exynos.git

powerpc/kretprobes: Override default function entry offset

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

mpe: NB this function is currently not called, the change to generic code to
call it is being merged via the tip tree.

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

diff --git a/arch/powerpc/kernel/kprobes.c b/arch/powerpc/kernel/kprobes.c
index 65828fb..97b5eed 100644
--- a/arch/powerpc/kernel/kprobes.c
+++ b/arch/powerpc/kernel/kprobes.c
@@ -189,6 +189,15 @@ 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)
 {