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authorNamhyung Kim <namhyung.kim@lge.com>2013-11-26 15:21:04 +0900
committerSteven Rostedt <rostedt@goodmis.org>2014-01-02 16:17:41 -0500
commit1301a44e77557e928700f91c7083c5770054c212 (patch)
treea2bb5e3dae59f410a2030790e1f2cdf2071e4487 /kernel/trace/trace_kprobe.c
parent3fd996a29515df23b3f20c36d69788a3707254a9 (diff)
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>
Diffstat (limited to 'kernel/trace/trace_kprobe.c')
-rw-r--r--kernel/trace/trace_kprobe.c59
1 files changed, 59 insertions, 0 deletions
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index 389f9e4744c8..d2a4fd2fd8c1 100644
--- 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 */