tracing/probes: Split [ku]probes_fetch_type_table

Use separate fetch_type_table for kprobes and uprobes.  It currently
shares all fetch methods but some of them will be implemented
differently later.

This is not to break build if [ku]probes is configured alone (like
!CONFIG_KPROBE_EVENT and CONFIG_UPROBE_EVENT).  So I added '__weak'
to the table declaration so that it can be safely omitted when it
configured out.

Acked-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: zhangwei(Jovi) <jovi.zhangwei@huawei.com>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>

4 files changed, 119 insertions, 39 deletions

diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index c9ffdafb9ada..fe3f00c381c0 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -88,6 +88,26 @@ static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs);
 static int kretprobe_dispatcher(struct kretprobe_instance *ri,
                                 struct pt_regs *regs);
 
+/* Fetch type information table */
+const struct fetch_type kprobes_fetch_type_table[] = {
+        /* Special types */
+        [FETCH_TYPE_STRING] = __ASSIGN_FETCH_TYPE("string", string, string,
+                                        sizeof(u32), 1, "__data_loc char[]"),
+        [FETCH_TYPE_STRSIZE] = __ASSIGN_FETCH_TYPE("string_size", u32,
+                                        string_size, sizeof(u32), 0, "u32"),
+        /* Basic types */
+        ASSIGN_FETCH_TYPE(u8,  u8,  0),
+        ASSIGN_FETCH_TYPE(u16, u16, 0),
+        ASSIGN_FETCH_TYPE(u32, u32, 0),
+        ASSIGN_FETCH_TYPE(u64, u64, 0),
+        ASSIGN_FETCH_TYPE(s8,  u8,  1),
+        ASSIGN_FETCH_TYPE(s16, u16, 1),
+        ASSIGN_FETCH_TYPE(s32, u32, 1),
+        ASSIGN_FETCH_TYPE(s64, u64, 1),
+
+        ASSIGN_FETCH_TYPE_END
+};
+
 /*
  * Allocate new trace_probe and initialize it (including kprobes).
  */
diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c
index c26bc9eaa2ac..541036ec7392 100644
--- a/kernel/trace/trace_probe.c
+++ b/kernel/trace/trace_probe.c
@@ -54,10 +54,6 @@ DEFINE_BASIC_PRINT_TYPE_FUNC(s16, "%d")
 DEFINE_BASIC_PRINT_TYPE_FUNC(s32, "%d")
 DEFINE_BASIC_PRINT_TYPE_FUNC(s64, "%Ld")
 
-/* For defining macros, define string/string_size types */
-typedef u32 string;
-typedef u32 string_size;
-
 /* Print type function for string type */
 __kprobes int PRINT_TYPE_FUNC_NAME(string)(struct trace_seq *s,
                                                   const char *name,
@@ -74,7 +70,6 @@ __kprobes int PRINT_TYPE_FUNC_NAME(string)(struct trace_seq *s,
 
 const char PRINT_TYPE_FMT_NAME(string)[] = "\\\"%s\\\"";
 
-#define FETCH_FUNC_NAME(method, type)   fetch_##method##_##type
 /*
  * Define macro for basic types - we don't need to define s* types, because
  * we have to care only about bitwidth at recording time.
@@ -359,25 +354,8 @@ free_bitfield_fetch_param(struct bitfield_fetch_param *data)
         kfree(data);
 }
 
-/* Fetch type information table */
-static const struct fetch_type fetch_type_table[] = {
-        /* Special types */
-        [FETCH_TYPE_STRING] = __ASSIGN_FETCH_TYPE("string", string, string,
-                                        sizeof(u32), 1, "__data_loc char[]"),
-        [FETCH_TYPE_STRSIZE] = __ASSIGN_FETCH_TYPE("string_size", u32,
-                                        string_size, sizeof(u32), 0, "u32"),
-        /* Basic types */
-        ASSIGN_FETCH_TYPE(u8,  u8,  0),
-        ASSIGN_FETCH_TYPE(u16, u16, 0),
-        ASSIGN_FETCH_TYPE(u32, u32, 0),
-        ASSIGN_FETCH_TYPE(u64, u64, 0),
-        ASSIGN_FETCH_TYPE(s8,  u8,  1),
-        ASSIGN_FETCH_TYPE(s16, u16, 1),
-        ASSIGN_FETCH_TYPE(s32, u32, 1),
-        ASSIGN_FETCH_TYPE(s64, u64, 1),
-};
-
-static const struct fetch_type *find_fetch_type(const char *type)
+static const struct fetch_type *find_fetch_type(const char *type,
+                                                const struct fetch_type *ftbl)
 {
         int i;
 
@@ -398,21 +376,22 @@ static const struct fetch_type *find_fetch_type(const char *type)
 
                 switch (bs) {
                 case 8:
-                        return find_fetch_type("u8");
+                        return find_fetch_type("u8", ftbl);
                 case 16:
-                        return find_fetch_type("u16");
+                        return find_fetch_type("u16", ftbl);
                 case 32:
-                        return find_fetch_type("u32");
+                        return find_fetch_type("u32", ftbl);
                 case 64:
-                        return find_fetch_type("u64");
+                        return find_fetch_type("u64", ftbl);
                 default:
                         goto fail;
                 }
         }
 
-        for (i = 0; i < ARRAY_SIZE(fetch_type_table); i++)
-                if (strcmp(type, fetch_type_table[i].name) == 0)
-                        return &fetch_type_table[i];
+        for (i = 0; ftbl[i].name; i++) {
+                if (strcmp(type, ftbl[i].name) == 0)
+                        return &ftbl[i];
+        }
 
 fail:
         return NULL;
@@ -426,16 +405,17 @@ static __kprobes void fetch_stack_address(struct pt_regs *regs,
 }
 
 static fetch_func_t get_fetch_size_function(const struct fetch_type *type,
-                                        fetch_func_t orig_fn)
+                                            fetch_func_t orig_fn,
+                                            const struct fetch_type *ftbl)
 {
         int i;
 
-        if (type != &fetch_type_table[FETCH_TYPE_STRING])
+        if (type != &ftbl[FETCH_TYPE_STRING])
                 return NULL;    /* Only string type needs size function */
 
         for (i = 0; i < FETCH_MTD_END; i++)
                 if (type->fetch[i] == orig_fn)
-                        return fetch_type_table[FETCH_TYPE_STRSIZE].fetch[i];
+                        return ftbl[FETCH_TYPE_STRSIZE].fetch[i];
 
         WARN_ON(1);     /* This should not happen */
 
@@ -504,12 +484,14 @@ static int parse_probe_vars(char *arg, const struct fetch_type *t,
 static int parse_probe_arg(char *arg, const struct fetch_type *t,
                      struct fetch_param *f, bool is_return, bool is_kprobe)
 {
+        const struct fetch_type *ftbl;
         unsigned long param;
         long offset;
         char *tmp;
-        int ret;
+        int ret = 0;
 
-        ret = 0;
+        ftbl = is_kprobe ? kprobes_fetch_type_table : uprobes_fetch_type_table;
+        BUG_ON(ftbl == NULL);
 
         /* Until uprobe_events supports only reg arguments */
         if (!is_kprobe && arg[0] != '%')
@@ -568,7 +550,7 @@ static int parse_probe_arg(char *arg, const struct fetch_type *t,
                         struct deref_fetch_param        *dprm;
                         const struct fetch_type         *t2;
 
-                        t2 = find_fetch_type(NULL);
+                        t2 = find_fetch_type(NULL, ftbl);
                         *tmp = '\0';
                         dprm = kzalloc(sizeof(struct deref_fetch_param), GFP_KERNEL);
 
@@ -637,9 +619,13 @@ static int __parse_bitfield_probe_arg(const char *bf,
 int traceprobe_parse_probe_arg(char *arg, ssize_t *size,
                 struct probe_arg *parg, bool is_return, bool is_kprobe)
 {
+        const struct fetch_type *ftbl;
         const char *t;
         int ret;
 
+        ftbl = is_kprobe ? kprobes_fetch_type_table : uprobes_fetch_type_table;
+        BUG_ON(ftbl == NULL);
+
         if (strlen(arg) > MAX_ARGSTR_LEN) {
                 pr_info("Argument is too long.: %s\n",  arg);
                 return -ENOSPC;
@@ -654,7 +640,7 @@ int traceprobe_parse_probe_arg(char *arg, ssize_t *size,
                 arg[t - parg->comm] = '\0';
                 t++;
         }
-        parg->type = find_fetch_type(t);
+        parg->type = find_fetch_type(t, ftbl);
         if (!parg->type) {
                 pr_info("Unsupported type: %s\n", t);
                 return -EINVAL;
@@ -668,7 +654,8 @@ int traceprobe_parse_probe_arg(char *arg, ssize_t *size,
 
         if (ret >= 0) {
                 parg->fetch_size.fn = get_fetch_size_function(parg->type,
-                                                              parg->fetch.fn);
+                                                              parg->fetch.fn,
+                                                              ftbl);
                 parg->fetch_size.data = parg->fetch.data;
         }
 
diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h
index bd621c08b6c6..5b77798d1130 100644
--- a/kernel/trace/trace_probe.h
+++ b/kernel/trace/trace_probe.h
@@ -126,6 +126,10 @@ struct fetch_param {
         void                    *data;
 };
 
+/* For defining macros, define string/string_size types */
+typedef u32 string;
+typedef u32 string_size;
+
 #define PRINT_TYPE_FUNC_NAME(type)      print_type_##type
 #define PRINT_TYPE_FMT_NAME(type)       print_type_format_##type
 
@@ -146,6 +150,47 @@ DECLARE_BASIC_PRINT_TYPE_FUNC(s32);
 DECLARE_BASIC_PRINT_TYPE_FUNC(s64);
 DECLARE_BASIC_PRINT_TYPE_FUNC(string);
 
+#define FETCH_FUNC_NAME(method, type)   fetch_##method##_##type
+
+/* Declare macro for basic types */
+#define DECLARE_FETCH_FUNC(method, type)                                \
+extern void FETCH_FUNC_NAME(method, type)(struct pt_regs *regs,         \
+                                          void *data, void *dest)
+
+#define DECLARE_BASIC_FETCH_FUNCS(method)       \
+DECLARE_FETCH_FUNC(method, u8);                 \
+DECLARE_FETCH_FUNC(method, u16);                \
+DECLARE_FETCH_FUNC(method, u32);                \
+DECLARE_FETCH_FUNC(method, u64)
+
+DECLARE_BASIC_FETCH_FUNCS(reg);
+#define fetch_reg_string                        NULL
+#define fetch_reg_string_size                   NULL
+
+DECLARE_BASIC_FETCH_FUNCS(stack);
+#define fetch_stack_string                      NULL
+#define fetch_stack_string_size                 NULL
+
+DECLARE_BASIC_FETCH_FUNCS(retval);
+#define fetch_retval_string                     NULL
+#define fetch_retval_string_size                NULL
+
+DECLARE_BASIC_FETCH_FUNCS(memory);
+DECLARE_FETCH_FUNC(memory, string);
+DECLARE_FETCH_FUNC(memory, string_size);
+
+DECLARE_BASIC_FETCH_FUNCS(symbol);
+DECLARE_FETCH_FUNC(symbol, string);
+DECLARE_FETCH_FUNC(symbol, string_size);
+
+DECLARE_BASIC_FETCH_FUNCS(deref);
+DECLARE_FETCH_FUNC(deref, string);
+DECLARE_FETCH_FUNC(deref, string_size);
+
+DECLARE_BASIC_FETCH_FUNCS(bitfield);
+#define fetch_bitfield_string                   NULL
+#define fetch_bitfield_string_size              NULL
+
 /* Default (unsigned long) fetch type */
 #define __DEFAULT_FETCH_TYPE(t) u##t
 #define _DEFAULT_FETCH_TYPE(t) __DEFAULT_FETCH_TYPE(t)
@@ -176,9 +221,17 @@ ASSIGN_FETCH_FUNC(bitfield, ftype),			\
 #define ASSIGN_FETCH_TYPE(ptype, ftype, sign)                   \
         __ASSIGN_FETCH_TYPE(#ptype, ptype, ftype, sizeof(ftype), sign, #ptype)
 
+#define ASSIGN_FETCH_TYPE_END {}
+
 #define FETCH_TYPE_STRING       0
 #define FETCH_TYPE_STRSIZE      1
 
+/*
+ * Fetch type information table.
+ * It's declared as a weak symbol due to conditional compilation.
+ */
+extern __weak const struct fetch_type kprobes_fetch_type_table[];
+extern __weak const struct fetch_type uprobes_fetch_type_table[];
 
 struct probe_arg {
         struct fetch_param      fetch;
diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c
index b233d9cb1216..2c60925ea073 100644
--- a/kernel/trace/trace_uprobe.c
+++ b/kernel/trace/trace_uprobe.c
@@ -74,6 +74,26 @@ static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs);
 static int uretprobe_dispatcher(struct uprobe_consumer *con,
                                 unsigned long func, struct pt_regs *regs);
 
+/* Fetch type information table */
+const struct fetch_type uprobes_fetch_type_table[] = {
+        /* Special types */
+        [FETCH_TYPE_STRING] = __ASSIGN_FETCH_TYPE("string", string, string,
+                                        sizeof(u32), 1, "__data_loc char[]"),
+        [FETCH_TYPE_STRSIZE] = __ASSIGN_FETCH_TYPE("string_size", u32,
+                                        string_size, sizeof(u32), 0, "u32"),
+        /* Basic types */
+        ASSIGN_FETCH_TYPE(u8,  u8,  0),
+        ASSIGN_FETCH_TYPE(u16, u16, 0),
+        ASSIGN_FETCH_TYPE(u32, u32, 0),
+        ASSIGN_FETCH_TYPE(u64, u64, 0),
+        ASSIGN_FETCH_TYPE(s8,  u8,  1),
+        ASSIGN_FETCH_TYPE(s16, u16, 1),
+        ASSIGN_FETCH_TYPE(s32, u32, 1),
+        ASSIGN_FETCH_TYPE(s64, u64, 1),
+
+        ASSIGN_FETCH_TYPE_END
+};
+
 static inline void init_trace_uprobe_filter(struct trace_uprobe_filter *filter)
 {
         rwlock_init(&filter->rwlock);