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-rw-r--r--arch/arm64/kernel/patching.c75
1 files changed, 75 insertions, 0 deletions
diff --git a/arch/arm64/kernel/patching.c b/arch/arm64/kernel/patching.c
index b4835f6d59..2555349303 100644
--- a/arch/arm64/kernel/patching.c
+++ b/arch/arm64/kernel/patching.c
@@ -105,6 +105,81 @@ noinstr int aarch64_insn_write_literal_u64(void *addr, u64 val)
return ret;
}
+typedef void text_poke_f(void *dst, void *src, size_t patched, size_t len);
+
+static void *__text_poke(text_poke_f func, void *addr, void *src, size_t len)
+{
+ unsigned long flags;
+ size_t patched = 0;
+ size_t size;
+ void *waddr;
+ void *ptr;
+
+ raw_spin_lock_irqsave(&patch_lock, flags);
+
+ while (patched < len) {
+ ptr = addr + patched;
+ size = min_t(size_t, PAGE_SIZE - offset_in_page(ptr),
+ len - patched);
+
+ waddr = patch_map(ptr, FIX_TEXT_POKE0);
+ func(waddr, src, patched, size);
+ patch_unmap(FIX_TEXT_POKE0);
+
+ patched += size;
+ }
+ raw_spin_unlock_irqrestore(&patch_lock, flags);
+
+ flush_icache_range((uintptr_t)addr, (uintptr_t)addr + len);
+
+ return addr;
+}
+
+static void text_poke_memcpy(void *dst, void *src, size_t patched, size_t len)
+{
+ copy_to_kernel_nofault(dst, src + patched, len);
+}
+
+static void text_poke_memset(void *dst, void *src, size_t patched, size_t len)
+{
+ u32 c = *(u32 *)src;
+
+ memset32(dst, c, len / 4);
+}
+
+/**
+ * aarch64_insn_copy - Copy instructions into (an unused part of) RX memory
+ * @dst: address to modify
+ * @src: source of the copy
+ * @len: length to copy
+ *
+ * Useful for JITs to dump new code blocks into unused regions of RX memory.
+ */
+noinstr void *aarch64_insn_copy(void *dst, void *src, size_t len)
+{
+ /* A64 instructions must be word aligned */
+ if ((uintptr_t)dst & 0x3)
+ return NULL;
+
+ return __text_poke(text_poke_memcpy, dst, src, len);
+}
+
+/**
+ * aarch64_insn_set - memset for RX memory regions.
+ * @dst: address to modify
+ * @insn: value to set
+ * @len: length of memory region.
+ *
+ * Useful for JITs to fill regions of RX memory with illegal instructions.
+ */
+noinstr void *aarch64_insn_set(void *dst, u32 insn, size_t len)
+{
+ if ((uintptr_t)dst & 0x3)
+ return NULL;
+
+ return __text_poke(text_poke_memset, dst, &insn, len);
+}
+
int __kprobes aarch64_insn_patch_text_nosync(void *addr, u32 insn)
{
u32 *tp = addr;