[PATCH 07/13] powerpc/kprobes: Unpoison instruction in kprobe struct

From: Nicholas Miehlbradt
Date: Thu Dec 14 2023 - 00:57:48 EST


KMSAN does not unpoison the ainsn field of a kprobe struct correctly.
Manually unpoison it to prevent false positives.

Signed-off-by: Nicholas Miehlbradt <nicholas@xxxxxxxxxxxxx>
---
arch/powerpc/kernel/kprobes.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/arch/powerpc/kernel/kprobes.c b/arch/powerpc/kernel/kprobes.c
index b20ee72e873a..1cbec54f2b6a 100644
--- a/arch/powerpc/kernel/kprobes.c
+++ b/arch/powerpc/kernel/kprobes.c
@@ -27,6 +27,7 @@
#include <asm/sections.h>
#include <asm/inst.h>
#include <linux/uaccess.h>
+#include <linux/kmsan-checks.h>

DEFINE_PER_CPU(struct kprobe *, current_kprobe) = NULL;
DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk);
@@ -179,6 +180,7 @@ int arch_prepare_kprobe(struct kprobe *p)

if (!ret) {
patch_instruction(p->ainsn.insn, insn);
+ kmsan_unpoison_memory(p->ainsn.insn, sizeof(kprobe_opcode_t));
p->opcode = ppc_inst_val(insn);
}

--
2.40.1