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 <hbath...@linux.ibm.com>
---
 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

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