tracing/probes: Move 'symbol' fetch method to kprobes

Move existing functions to trace_kprobe.c and add NULL entries to the
uprobes fetch type table.  I don't make them static since some generic
routines like update/free_XXX_fetch_param() require pointers to the
functions.

Acked-by: Oleg Nesterov <oleg@redhat.com>
Cc: 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>

diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index 389f9e4..d2a4fd2 100644 (file)
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -88,6 +88,51 @@ static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs);
 static int kretprobe_dispatcher(struct kretprobe_instance *ri,
                                struct pt_regs *regs);
 
+/* Memory fetching by symbol */
+struct symbol_cache {
+       char            *symbol;
+       long            offset;
+       unsigned long   addr;
+};
+
+unsigned long update_symbol_cache(struct symbol_cache *sc)
+{
+       sc->addr = (unsigned long)kallsyms_lookup_name(sc->symbol);
+
+       if (sc->addr)
+               sc->addr += sc->offset;
+
+       return sc->addr;
+}
+
+void free_symbol_cache(struct symbol_cache *sc)
+{
+       kfree(sc->symbol);
+       kfree(sc);
+}
+
+struct symbol_cache *alloc_symbol_cache(const char *sym, long offset)
+{
+       struct symbol_cache *sc;
+
+       if (!sym || strlen(sym) == 0)
+               return NULL;
+
+       sc = kzalloc(sizeof(struct symbol_cache), GFP_KERNEL);
+       if (!sc)
+               return NULL;
+
+       sc->symbol = kstrdup(sym, GFP_KERNEL);
+       if (!sc->symbol) {
+               kfree(sc);
+               return NULL;
+       }
+       sc->offset = offset;
+       update_symbol_cache(sc);
+
+       return sc;
+}
+
 /*
  * Kprobes-specific fetch functions
  */
@@ -103,6 +148,20 @@ DEFINE_BASIC_FETCH_FUNCS(stack)
 #define fetch_stack_string     NULL
 #define fetch_stack_string_size        NULL
 
+#define DEFINE_FETCH_symbol(type)                                      \
+__kprobes void FETCH_FUNC_NAME(symbol, type)(struct pt_regs *regs,     \
+                                         void *data, void *dest)       \
+{                                                                      \
+       struct symbol_cache *sc = data;                                 \
+       if (sc->addr)                                                   \
+               fetch_memory_##type(regs, (void *)sc->addr, dest);      \
+       else                                                            \
+               *(type *)dest = 0;                                      \
+}
+DEFINE_BASIC_FETCH_FUNCS(symbol)
+DEFINE_FETCH_symbol(string)
+DEFINE_FETCH_symbol(string_size)
+
 /* Fetch type information table */
 const struct fetch_type kprobes_fetch_type_table[] = {
        /* Special types */

diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c
index 77aa7d1..a31ad47 100644 (file)
--- a/kernel/trace/trace_probe.c
+++ b/kernel/trace/trace_probe.c
@@ -180,65 +180,6 @@ __kprobes void FETCH_FUNC_NAME(memory, string_size)(struct pt_regs *regs,
                *(u32 *)dest = len;
 }
 
-/* Memory fetching by symbol */
-struct symbol_cache {
-       char            *symbol;
-       long            offset;
-       unsigned long   addr;
-};
-
-static unsigned long update_symbol_cache(struct symbol_cache *sc)
-{
-       sc->addr = (unsigned long)kallsyms_lookup_name(sc->symbol);
-
-       if (sc->addr)
-               sc->addr += sc->offset;
-
-       return sc->addr;
-}
-
-static void free_symbol_cache(struct symbol_cache *sc)
-{
-       kfree(sc->symbol);
-       kfree(sc);
-}
-
-static struct symbol_cache *alloc_symbol_cache(const char *sym, long offset)
-{
-       struct symbol_cache *sc;
-
-       if (!sym || strlen(sym) == 0)
-               return NULL;
-
-       sc = kzalloc(sizeof(struct symbol_cache), GFP_KERNEL);
-       if (!sc)
-               return NULL;
-
-       sc->symbol = kstrdup(sym, GFP_KERNEL);
-       if (!sc->symbol) {
-               kfree(sc);
-               return NULL;
-       }
-       sc->offset = offset;
-       update_symbol_cache(sc);
-
-       return sc;
-}
-
-#define DEFINE_FETCH_symbol(type)                                      \
-__kprobes void FETCH_FUNC_NAME(symbol, type)(struct pt_regs *regs,     \
-                                         void *data, void *dest)       \
-{                                                                      \
-       struct symbol_cache *sc = data;                                 \
-       if (sc->addr)                                                   \
-               fetch_memory_##type(regs, (void *)sc->addr, dest);      \
-       else                                                            \
-               *(type *)dest = 0;                                      \
-}
-DEFINE_BASIC_FETCH_FUNCS(symbol)
-DEFINE_FETCH_symbol(string)
-DEFINE_FETCH_symbol(string_size)
-
 /* Dereference memory access function */
 struct deref_fetch_param {
        struct fetch_param      orig;

diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h
index 8211dd6..8be8455 100644 (file)
--- a/kernel/trace/trace_probe.h
+++ b/kernel/trace/trace_probe.h
@@ -239,6 +239,30 @@ ASSIGN_FETCH_FUNC(bitfield, ftype),                        \
 extern __weak const struct fetch_type kprobes_fetch_type_table[];
 extern __weak const struct fetch_type uprobes_fetch_type_table[];
 
+#ifdef CONFIG_KPROBE_EVENT
+struct symbol_cache;
+unsigned long update_symbol_cache(struct symbol_cache *sc);
+void free_symbol_cache(struct symbol_cache *sc);
+struct symbol_cache *alloc_symbol_cache(const char *sym, long offset);
+#else
+struct symbol_cache {
+};
+static inline unsigned long __used update_symbol_cache(struct symbol_cache *sc)
+{
+       return 0;
+}
+
+static inline void __used free_symbol_cache(struct symbol_cache *sc)
+{
+}
+
+static inline struct symbol_cache * __used
+alloc_symbol_cache(const char *sym, long offset)
+{
+       return NULL;
+}
+#endif /* CONFIG_KPROBE_EVENT */
+
 struct probe_arg {
        struct fetch_param      fetch;
        struct fetch_param      fetch_size;

diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c
index 5395d37..24ef6a3 100644 (file)
--- a/kernel/trace/trace_uprobe.c
+++ b/kernel/trace/trace_uprobe.c
@@ -115,6 +115,14 @@ DEFINE_BASIC_FETCH_FUNCS(stack)
 #define fetch_stack_string_size        NULL
 
 
+/* uprobes do not support symbol fetch methods */
+#define fetch_symbol_u8                        NULL
+#define fetch_symbol_u16               NULL
+#define fetch_symbol_u32               NULL
+#define fetch_symbol_u64               NULL
+#define fetch_symbol_string            NULL
+#define fetch_symbol_string_size       NULL
+
 /* Fetch type information table */
 const struct fetch_type uprobes_fetch_type_table[] = {
        /* Special types */