Subject: [PATCH v2 3/4] powerpc/bpf: implement bpf_arch_text_invalidate for bpf_prog_pack

From: Hari Bathini <[email-masked]>
Date: Thu, 9 Mar 2023 23:32:12 +0530

Implement bpf_arch_text_invalidate and use it to fill unused part of
the bpf_prog_pack with trap instructions when a BPF program is freed.

Signed-off-by: Hari Bathini <[email-masked]>
---
 arch/powerpc/net/bpf_jit_comp.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/arch/powerpc/net/bpf_jit_comp.c b/arch/powerpc/net/bpf_jit_comp.c
index 0a70319116d1..d1794d9f0154 100644
--- a/arch/powerpc/net/bpf_jit_comp.c
+++ b/arch/powerpc/net/bpf_jit_comp.c
@@ -293,3 +293,18 @@ void *bpf_arch_text_copy(void *dst, void *src, size_t len)
 
 	return ret;
 }
+
+int bpf_arch_text_invalidate(void *dst, size_t len)
+{
+	u32 inst = BREAKPOINT_INSTRUCTION;
+	int ret = -EINVAL;
+
+	if (WARN_ON_ONCE(core_kernel_text((unsigned long)dst)))
+		return ret;
+
+	mutex_lock(&text_mutex);
+	ret = patch_instructions(dst, &inst, true, len);
+	mutex_unlock(&text_mutex);
+
+	return ret;
+}
-- 
2.39.2