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Commit 1301a44e authored Nov 26, 2013 by Namhyung Kim Committed by Steven Rostedt Jan 02, 2014

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>

parent 3fd996a2

kernel/trace/trace_kprobe.c

+59 −0

Original line number	Diff line number	Diff line
		@@ -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 */

kernel/trace/trace_probe.c

+0 −59

Original line number	Diff line number	Diff line
		@@ -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;

kernel/trace/trace_probe.h

+24 −0

Original line number	Diff line number	Diff line
		@@ -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;

kernel/trace/trace_uprobe.c

+8 −0

Original line number	Diff line number	Diff line
		@@ -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 */