Implement arch_fill_execmem() and arch_invalidate_execmem() to support
execmem_alloc.
arch_fill_execmem() copies dynamic kernel text (such as BPF programs) to
RO+X memory region allocated by execmem_alloc().
arch_invalidate_execmem() fills memory with 0xcc after it is released by
execmem_free().
Signed-off-by: Song Liu <song@xxxxxxxxxx>
---
arch/x86/kernel/alternative.c | 12 ++++++++++++
1 file changed, 12 insertions(+)
diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c
index 5cadcea035e0..e38829f19a81 100644
--- a/arch/x86/kernel/alternative.c
+++ b/arch/x86/kernel/alternative.c
@@ -1270,6 +1270,18 @@ void *text_poke_copy(void *addr, const void *opcode, size_t len)
return addr;
}
+void *arch_fill_execmem(void *dst, void *src, size_t len)
+{
+ if (text_poke_copy(dst, src, len) == NULL)
+ return ERR_PTR(-EINVAL);
+ return dst;
+}
+
+int arch_invalidate_execmem(void *ptr, size_t len)
+{
+ return IS_ERR_OR_NULL(text_poke_set(ptr, 0xcc, len));
+}
+
/**
* text_poke_set - memset into (an unused part of) RX memory
* @addr: address to modify
--
2.30.2
