Add some helper macros which can be used by livepatch source .patch
files to register callbacks or patch syscalls.
Signed-off-by: Josh Poimboeuf <jpoim...@kernel.org>
---
include/linux/livepatch_helpers.h | 68 +++++++++++++++++++++++++++++++
1 file changed, 68 insertions(+)
create mode 100644 include/linux/livepatch_helpers.h
diff --git a/include/linux/livepatch_helpers.h
b/include/linux/livepatch_helpers.h
new file mode 100644
index 000000000000..09f4a2d53fd7
--- /dev/null
+++ b/include/linux/livepatch_helpers.h
@@ -0,0 +1,68 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _LINUX_LIVEPATCH_HELPERS_H
+#define _LINUX_LIVEPATCH_HELPERS_H
+
+/*
+ * Interfaces for use by livepatch patches
+ */
+
+#include <linux/syscalls.h>
+#include <linux/livepatch.h>
+
+#ifdef MODULE
+#define KLP_OBJNAME __KBUILD_MODNAME
+#else
+#define KLP_OBJNAME vmlinux
+#endif
+
+/* Livepatch callback registration */
+
+#define KLP_CALLBACK_PTRS ".discard.klp_callback_ptrs"
+
+#define KLP_PRE_PATCH_CALLBACK(func)
\
+ klp_pre_patch_t __used __section(KLP_CALLBACK_PTRS)
\
+ __PASTE(__KLP_PRE_PATCH_PREFIX, KLP_OBJNAME) = func
+
+#define KLP_POST_PATCH_CALLBACK(func)
\
+ klp_post_patch_t __used __section(KLP_CALLBACK_PTRS)
\
+ __PASTE(__KLP_POST_PATCH_PREFIX, KLP_OBJNAME) = func
+
+#define KLP_PRE_UNPATCH_CALLBACK(func)
\
+ klp_pre_unpatch_t __used __section(KLP_CALLBACK_PTRS)
\
+ __PASTE(__KLP_PRE_UNPATCH_PREFIX, KLP_OBJNAME) = func
+
+#define KLP_POST_UNPATCH_CALLBACK(func)
\
+ klp_post_unpatch_t __used __section(KLP_CALLBACK_PTRS)
\
+ __PASTE(__KLP_POST_UNPATCH_PREFIX, KLP_OBJNAME) = func
+
+/* Syscall patching */
+
+#define KLP_SYSCALL_DEFINE1(name, ...) KLP_SYSCALL_DEFINEx(1, _##name,
__VA_ARGS__)
+#define KLP_SYSCALL_DEFINE2(name, ...) KLP_SYSCALL_DEFINEx(2, _##name,
__VA_ARGS__)
+#define KLP_SYSCALL_DEFINE3(name, ...) KLP_SYSCALL_DEFINEx(3, _##name,
__VA_ARGS__)
+#define KLP_SYSCALL_DEFINE4(name, ...) KLP_SYSCALL_DEFINEx(4, _##name,
__VA_ARGS__)
+#define KLP_SYSCALL_DEFINE5(name, ...) KLP_SYSCALL_DEFINEx(5, _##name,
__VA_ARGS__)
+#define KLP_SYSCALL_DEFINE6(name, ...) KLP_SYSCALL_DEFINEx(6, _##name,
__VA_ARGS__)
+
+#define KLP_SYSCALL_DEFINEx(x, sname, ...) \
+ __KLP_SYSCALL_DEFINEx(x, sname, __VA_ARGS__)
+
+#ifdef CONFIG_X86_64
+// TODO move this to arch/x86/include/asm/syscall_wrapper.h and share code
+#define __KLP_SYSCALL_DEFINEx(x, name, ...) \
+ static long __se_sys##name(__MAP(x,__SC_LONG,__VA_ARGS__)); \
+ static inline long __klp_do_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__));\
+ __X64_SYS_STUBx(x, name, __VA_ARGS__) \
+ __IA32_SYS_STUBx(x, name, __VA_ARGS__) \
+ static long __se_sys##name(__MAP(x,__SC_LONG,__VA_ARGS__)) \
+ { \
+ long ret = __klp_do_sys##name(__MAP(x,__SC_CAST,__VA_ARGS__));\
+ __MAP(x,__SC_TEST,__VA_ARGS__); \
+ __PROTECT(x, ret,__MAP(x,__SC_ARGS,__VA_ARGS__)); \
+ return ret; \
+ } \
+ static inline long __klp_do_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__))
+
+#endif
+
+#endif /* _LINUX_LIVEPATCH_HELPERS_H */
--
2.49.0
