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-rw-r--r--arch/x86/kernel/alternative.c18
1 files changed, 16 insertions, 2 deletions
diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c
index e377b06e70e3..74f4c659f9c9 100644
--- a/arch/x86/kernel/alternative.c
+++ b/arch/x86/kernel/alternative.c
@@ -2453,16 +2453,30 @@ void __init_or_module text_poke_early(void *addr, const void *opcode,
__ro_after_init struct mm_struct *text_poke_mm;
__ro_after_init unsigned long text_poke_mm_addr;
+/*
+ * Text poking creates and uses a mapping in the lower half of the
+ * address space. Relax LASS enforcement when accessing the poking
+ * address.
+ *
+ * objtool enforces a strict policy of "no function calls within AC=1
+ * regions". Adhere to the policy by using inline versions of
+ * memcpy()/memset() that will never result in a function call.
+ */
+
static void text_poke_memcpy(void *dst, const void *src, size_t len)
{
- memcpy(dst, src, len);
+ lass_stac();
+ __inline_memcpy(dst, src, len);
+ lass_clac();
}
static void text_poke_memset(void *dst, const void *src, size_t len)
{
int c = *(const int *)src;
- memset(dst, c, len);
+ lass_stac();
+ __inline_memset(dst, c, len);
+ lass_clac();
}
typedef void text_poke_f(void *dst, const void *src, size_t len);