2 files changed, 69 insertions, 5 deletions

diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h
index c146c1021a29..6dc1c652447e 100644
--- a/include/linux/ftrace.h
+++ b/include/linux/ftrace.h
@@ -506,13 +506,21 @@ static inline void trace_hw_branch_oops(void) {}
 /*
  * A syscall entry in the ftrace syscalls array.
  *
- * @syscall_nr: syscall number
+ * @name: name of the syscall
+ * @nb_args: number of parameters it takes
+ * @types: list of types as strings
+ * @args: list of args as strings (args[i] matches types[i])
  */
-struct syscall_trace_entry {
-        int             syscall_nr;
+struct syscall_metadata {
+        const char      *name;
+        int             nb_args;
+        const char      **types;
+        const char      **args;
 };
 
 #ifdef CONFIG_FTRACE_SYSCALLS
+extern void arch_init_ftrace_syscalls(void);
+extern struct syscall_metadata *syscall_nr_to_meta(int nr);
 extern void start_ftrace_syscalls(void);
 extern void stop_ftrace_syscalls(void);
 extern void ftrace_syscall_enter(struct pt_regs *regs);
diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index f9f900cfd066..0cff9bb80b02 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -65,6 +65,7 @@ struct old_linux_dirent;
 #include <asm/signal.h>
 #include <linux/quota.h>
 #include <linux/key.h>
+#include <linux/ftrace.h>
 
 #define __SC_DECL1(t1, a1)      t1 a1
 #define __SC_DECL2(t2, a2, ...) t2 a2, __SC_DECL1(__VA_ARGS__)
@@ -95,7 +96,46 @@ struct old_linux_dirent;
 #define __SC_TEST5(t5, a5, ...) __SC_TEST(t5); __SC_TEST4(__VA_ARGS__)
 #define __SC_TEST6(t6, a6, ...) __SC_TEST(t6); __SC_TEST5(__VA_ARGS__)
 
+#ifdef CONFIG_FTRACE_SYSCALLS
+#define __SC_STR_ADECL1(t, a)           #a
+#define __SC_STR_ADECL2(t, a, ...)      #a, __SC_STR_ADECL1(__VA_ARGS__)
+#define __SC_STR_ADECL3(t, a, ...)      #a, __SC_STR_ADECL2(__VA_ARGS__)
+#define __SC_STR_ADECL4(t, a, ...)      #a, __SC_STR_ADECL3(__VA_ARGS__)
+#define __SC_STR_ADECL5(t, a, ...)      #a, __SC_STR_ADECL4(__VA_ARGS__)
+#define __SC_STR_ADECL6(t, a, ...)      #a, __SC_STR_ADECL5(__VA_ARGS__)
+
+#define __SC_STR_TDECL1(t, a)           #t
+#define __SC_STR_TDECL2(t, a, ...)      #t, __SC_STR_TDECL1(__VA_ARGS__)
+#define __SC_STR_TDECL3(t, a, ...)      #t, __SC_STR_TDECL2(__VA_ARGS__)
+#define __SC_STR_TDECL4(t, a, ...)      #t, __SC_STR_TDECL3(__VA_ARGS__)
+#define __SC_STR_TDECL5(t, a, ...)      #t, __SC_STR_TDECL4(__VA_ARGS__)
+#define __SC_STR_TDECL6(t, a, ...)      #t, __SC_STR_TDECL5(__VA_ARGS__)
+
+#define SYSCALL_METADATA(sname, nb)                             \
+        static const struct syscall_metadata __used             \
+          __attribute__((__aligned__(4)))                       \
+          __attribute__((section("__syscalls_metadata")))       \
+          __syscall_meta_##sname = {                            \
+                .name           = "sys"#sname,                  \
+                .nb_args        = nb,                           \
+                .types          = types_##sname,                \
+                .args           = args_##sname,                 \
+        }
+
+#define SYSCALL_DEFINE0(sname)                                  \
+        static const struct syscall_metadata __used             \
+          __attribute__((__aligned__(4)))                       \
+          __attribute__((section("__syscalls_metadata")))       \
+          __syscall_meta_##sname = {                            \
+                .name           = "sys_"#sname,                 \
+                .nb_args        = 0,                            \
+        };                                                      \
+        asmlinkage long sys_##sname(void)
+
+#else
 #define SYSCALL_DEFINE0(name)      asmlinkage long sys_##name(void)
+#endif
+
 #define SYSCALL_DEFINE1(name, ...) SYSCALL_DEFINEx(1, _##name, __VA_ARGS__)
 #define SYSCALL_DEFINE2(name, ...) SYSCALL_DEFINEx(2, _##name, __VA_ARGS__)
 #define SYSCALL_DEFINE3(name, ...) SYSCALL_DEFINEx(3, _##name, __VA_ARGS__)
@@ -117,10 +157,26 @@ struct old_linux_dirent;
 #endif
 #endif
 
+#ifdef CONFIG_FTRACE_SYSCALLS
+#define SYSCALL_DEFINEx(x, sname, ...)                          \
+        static const char *types_##sname[] = {                  \
+                __SC_STR_TDECL##x(__VA_ARGS__)                  \
+        };                                                      \
+        static const char *args_##sname[] = {                   \
+                __SC_STR_ADECL##x(__VA_ARGS__)                  \
+        };                                                      \
+        SYSCALL_METADATA(sname, x);                             \
+        __SYSCALL_DEFINEx(x, sname, __VA_ARGS__)
+#else
+#define SYSCALL_DEFINEx(x, sname, ...)                          \
+        __SYSCALL_DEFINEx(x, sname, __VA_ARGS__)
+#endif
+
 #ifdef CONFIG_HAVE_SYSCALL_WRAPPERS
 
 #define SYSCALL_DEFINE(name) static inline long SYSC_##name
-#define SYSCALL_DEFINEx(x, name, ...)                                   \
+
+#define __SYSCALL_DEFINEx(x, name, ...)                                 \
         asmlinkage long sys##name(__SC_DECL##x(__VA_ARGS__));           \
         static inline long SYSC##name(__SC_DECL##x(__VA_ARGS__));       \
         asmlinkage long SyS##name(__SC_LONG##x(__VA_ARGS__))            \
@@ -134,7 +190,7 @@ struct old_linux_dirent;
 #else /* CONFIG_HAVE_SYSCALL_WRAPPERS */
 
 #define SYSCALL_DEFINE(name) asmlinkage long sys_##name
-#define SYSCALL_DEFINEx(x, name, ...)                                   \
+#define __SYSCALL_DEFINEx(x, name, ...)                                 \
         asmlinkage long sys##name(__SC_DECL##x(__VA_ARGS__))
 
 #endif /* CONFIG_HAVE_SYSCALL_WRAPPERS */