[PATCH -tip v6 14/22] ftrace/kprobes: Use NOKPROBE_SYMBOL macro inftrace

From: Masami Hiramatsu
Date: Thu Dec 19 2013 - 04:22:29 EST

Use NOKPROBE_SYMBOL macro to protect functions from
kprobes instead of __kprobes annotation in ftrace.
This applies nokprobe_inline annotation for some cases,
because NOKPROBE_SYMBOL() will inhibit inlining by
referring the symbol address.

Changes from previous:
- Use nokprobe_inline for call_fetch (Thanks to Steven Rostedt)
- Use nokprobe_inline instead of __always_inline.
- Apply NOKPROBE_SYMBOL to __get_data_size and store_trace_args
(Thanks to Steven Rostedt)

Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@xxxxxxxxxxx>
Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
Cc: Frederic Weisbecker <fweisbec@xxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
---
kernel/trace/trace_event_perf.c | 5 ++-
kernel/trace/trace_kprobe.c | 51 +++++++++++++++------------
kernel/trace/trace_probe.c | 74 +++++++++++++++++++++++----------------
kernel/trace/trace_probe.h | 4 +-
4 files changed, 76 insertions(+), 58 deletions(-)

diff --git a/kernel/trace/trace_event_perf.c b/kernel/trace/trace_event_perf.c
index e854f42..c97a795 100644
--- a/kernel/trace/trace_event_perf.c
+++ b/kernel/trace/trace_event_perf.c
@@ -232,8 +232,8 @@ void perf_trace_del(struct perf_event *p_event, int flags)
tp_event->class->reg(tp_event, TRACE_REG_PERF_DEL, p_event);
}

-__kprobes void *perf_trace_buf_prepare(int size, unsigned short type,
- struct pt_regs *regs, int *rctxp)
+void *perf_trace_buf_prepare(int size, unsigned short type,
+ struct pt_regs *regs, int *rctxp)
{
struct trace_entry *entry;
unsigned long flags;
@@ -265,6 +265,7 @@ __kprobes void *perf_trace_buf_prepare(int size, unsigned short type,
return raw_data;
}
EXPORT_SYMBOL_GPL(perf_trace_buf_prepare);
+NOKPROBE_SYMBOL(perf_trace_buf_prepare);

#ifdef CONFIG_FUNCTION_TRACER
static void
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index f8fa5bc..2c54fee 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -51,45 +51,45 @@ struct event_file_link {
(sizeof(struct probe_arg) * (n)))


-static __kprobes bool trace_probe_is_return(struct trace_probe *tp)
+static nokprobe_inline bool trace_probe_is_return(struct trace_probe *tp)
{
return tp->rp.handler != NULL;
}

-static __kprobes const char *trace_probe_symbol(struct trace_probe *tp)
+static nokprobe_inline const char *trace_probe_symbol(struct trace_probe *tp)
{
return tp->symbol ? tp->symbol : "unknown";
}

-static __kprobes unsigned long trace_probe_offset(struct trace_probe *tp)
+static nokprobe_inline unsigned long trace_probe_offset(struct trace_probe *tp)
{
return tp->rp.kp.offset;
}

-static __kprobes bool trace_probe_is_enabled(struct trace_probe *tp)
+static nokprobe_inline bool trace_probe_is_enabled(struct trace_probe *tp)
{
return !!(tp->flags & (TP_FLAG_TRACE | TP_FLAG_PROFILE));
}

-static __kprobes bool trace_probe_is_registered(struct trace_probe *tp)
+static nokprobe_inline bool trace_probe_is_registered(struct trace_probe *tp)
{
return !!(tp->flags & TP_FLAG_REGISTERED);
}

-static __kprobes bool trace_probe_has_gone(struct trace_probe *tp)
+static nokprobe_inline bool trace_probe_has_gone(struct trace_probe *tp)
{
return !!(kprobe_gone(&tp->rp.kp));
}

-static __kprobes bool trace_probe_within_module(struct trace_probe *tp,
- struct module *mod)
+static nokprobe_inline bool trace_probe_within_module(struct trace_probe *tp,
+ struct module *mod)
{
int len = strlen(mod->name);
const char *name = trace_probe_symbol(tp);
return strncmp(mod->name, name, len) == 0 && name[len] == ':';
}

-static __kprobes bool trace_probe_is_on_module(struct trace_probe *tp)
+static nokprobe_inline bool trace_probe_is_on_module(struct trace_probe *tp)
{
return !!strchr(trace_probe_symbol(tp), ':');
}
@@ -755,8 +755,7 @@ static const struct file_operations kprobe_profile_ops = {
};

/* Sum up total data length for dynamic arraies (strings) */
-static __kprobes int __get_data_size(struct trace_probe *tp,
- struct pt_regs *regs)
+static int __get_data_size(struct trace_probe *tp, struct pt_regs *regs)
{
int i, ret = 0;
u32 len;
@@ -769,11 +768,11 @@ static __kprobes int __get_data_size(struct trace_probe *tp,

return ret;
}
+NOKPROBE_SYMBOL(__get_data_size);

/* Store the value of each argument */
-static __kprobes void store_trace_args(int ent_size, struct trace_probe *tp,
- struct pt_regs *regs,
- u8 *data, int maxlen)
+static void store_trace_args(int ent_size, struct trace_probe *tp,
+ struct pt_regs *regs, u8 *data, int maxlen)
{
int i;
u32 end = tp->size;
@@ -801,9 +800,10 @@ static __kprobes void store_trace_args(int ent_size, struct trace_probe *tp,
data + tp->args[i].offset);
}
}
+NOKPROBE_SYMBOL(store_trace_args);

/* Kprobe handler */
-static __kprobes void
+static nokprobe_inline void
__kprobe_trace_func(struct trace_probe *tp, struct pt_regs *regs,
struct ftrace_event_file *ftrace_file)
{
@@ -840,7 +840,7 @@ __kprobe_trace_func(struct trace_probe *tp, struct pt_regs *regs,
irq_flags, pc, regs);
}

-static __kprobes void
+static void
kprobe_trace_func(struct trace_probe *tp, struct pt_regs *regs)
{
struct event_file_link *link;
@@ -848,9 +848,10 @@ kprobe_trace_func(struct trace_probe *tp, struct pt_regs *regs)
list_for_each_entry_rcu(link, &tp->files, list)
__kprobe_trace_func(tp, regs, link->file);
}
+NOKPROBE_SYMBOL(kprobe_trace_func);

/* Kretprobe handler */
-static __kprobes void
+static nokprobe_inline void
__kretprobe_trace_func(struct trace_probe *tp, struct kretprobe_instance *ri,
struct pt_regs *regs,
struct ftrace_event_file *ftrace_file)
@@ -889,7 +890,7 @@ __kretprobe_trace_func(struct trace_probe *tp, struct kretprobe_instance *ri,
irq_flags, pc, regs);
}

-static __kprobes void
+static void
kretprobe_trace_func(struct trace_probe *tp, struct kretprobe_instance *ri,
struct pt_regs *regs)
{
@@ -898,6 +899,7 @@ kretprobe_trace_func(struct trace_probe *tp, struct kretprobe_instance *ri,
list_for_each_entry_rcu(link, &tp->files, list)
__kretprobe_trace_func(tp, ri, regs, link->file);
}
+NOKPROBE_SYMBOL(kretprobe_trace_func);

/* Event entry printers */
static enum print_line_t
@@ -1086,7 +1088,7 @@ static int set_print_fmt(struct trace_probe *tp)
#ifdef CONFIG_PERF_EVENTS

/* Kprobe profile handler */
-static __kprobes void
+static void
kprobe_perf_func(struct trace_probe *tp, struct pt_regs *regs)
{
struct ftrace_event_call *call = &tp->call;
@@ -1113,9 +1115,10 @@ kprobe_perf_func(struct trace_probe *tp, struct pt_regs *regs)
store_trace_args(sizeof(*entry), tp, regs, (u8 *)&entry[1], dsize);
perf_trace_buf_submit(entry, size, rctx, 0, 1, regs, head, NULL);
}
+NOKPROBE_SYMBOL(kprobe_perf_func);

/* Kretprobe profile handler */
-static __kprobes void
+static void
kretprobe_perf_func(struct trace_probe *tp, struct kretprobe_instance *ri,
struct pt_regs *regs)
{
@@ -1143,6 +1146,7 @@ kretprobe_perf_func(struct trace_probe *tp, struct kretprobe_instance *ri,
store_trace_args(sizeof(*entry), tp, regs, (u8 *)&entry[1], dsize);
perf_trace_buf_submit(entry, size, rctx, 0, 1, regs, head, NULL);
}
+NOKPROBE_SYMBOL(kretprobe_perf_func);
#endif /* CONFIG_PERF_EVENTS */

/*
@@ -1179,8 +1183,7 @@ int kprobe_register(struct ftrace_event_call *event,
return 0;
}

-static __kprobes
-int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs)
+static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs)
{
struct trace_probe *tp = container_of(kp, struct trace_probe, rp.kp);

@@ -1194,8 +1197,9 @@ int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs)
#endif
return 0; /* We don't tweek kernel, so just return 0 */
}
+NOKPROBE_SYMBOL(kprobe_dispatcher);

-static __kprobes
+static
int kretprobe_dispatcher(struct kretprobe_instance *ri, struct pt_regs *regs)
{
struct trace_probe *tp = container_of(ri->rp, struct trace_probe, rp);
@@ -1210,6 +1214,7 @@ int kretprobe_dispatcher(struct kretprobe_instance *ri, struct pt_regs *regs)
#endif
return 0; /* We don't tweek kernel, so just return 0 */
}
+NOKPROBE_SYMBOL(kretprobe_dispatcher);

static struct trace_event_functions kretprobe_funcs = {
.trace = print_kretprobe_event
diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c
index 43638a2..314bdc6 100644
--- a/kernel/trace/trace_probe.c
+++ b/kernel/trace/trace_probe.c
@@ -41,13 +41,14 @@ const char *reserved_field_names[] = {

/* Printing in basic type function template */
#define DEFINE_BASIC_PRINT_TYPE_FUNC(type, fmt, cast) \
-static __kprobes int PRINT_TYPE_FUNC_NAME(type)(struct trace_seq *s, \
- const char *name, \
- void *data, void *ent)\
+static int PRINT_TYPE_FUNC_NAME(type)(struct trace_seq *s, \
+ const char *name, \
+ void *data, void *ent) \
{ \
return trace_seq_printf(s, " %s=" fmt, name, (cast)*(type *)data);\
} \
-static const char PRINT_TYPE_FMT_NAME(type)[] = fmt;
+static const char PRINT_TYPE_FMT_NAME(type)[] = fmt; \
+NOKPROBE_SYMBOL(PRINT_TYPE_FUNC_NAME(type));

DEFINE_BASIC_PRINT_TYPE_FUNC(u8, "%x", unsigned int)
DEFINE_BASIC_PRINT_TYPE_FUNC(u16, "%x", unsigned int)
@@ -74,9 +75,9 @@ typedef u32 string;
typedef u32 string_size;

/* Print type function for string type */
-static __kprobes int PRINT_TYPE_FUNC_NAME(string)(struct trace_seq *s,
- const char *name,
- void *data, void *ent)
+static int PRINT_TYPE_FUNC_NAME(string)(struct trace_seq *s,
+ const char *name,
+ void *data, void *ent)
{
int len = *(u32 *)data >> 16;

@@ -86,6 +87,7 @@ static __kprobes int PRINT_TYPE_FUNC_NAME(string)(struct trace_seq *s,
return trace_seq_printf(s, " %s=\"%s\"", name,
(const char *)get_loc_data(data, ent));
}
+NOKPROBE_SYMBOL(PRINT_TYPE_FUNC_NAME(string));

static const char PRINT_TYPE_FMT_NAME(string)[] = "\\\"%s\\\"";

@@ -111,42 +113,45 @@ DEFINE_FETCH_##method(u64)

/* Data fetch function templates */
#define DEFINE_FETCH_reg(type) \
-static __kprobes void FETCH_FUNC_NAME(reg, type)(struct pt_regs *regs, \
+static void FETCH_FUNC_NAME(reg, type)(struct pt_regs *regs, \
void *offset, void *dest) \
{ \
*(type *)dest = (type)regs_get_register(regs, \
(unsigned int)((unsigned long)offset)); \
-}
+} \
+NOKPROBE_SYMBOL(FETCH_FUNC_NAME(reg, type));
DEFINE_BASIC_FETCH_FUNCS(reg)
/* No string on the register */
#define fetch_reg_string NULL
#define fetch_reg_string_size NULL

#define DEFINE_FETCH_stack(type) \
-static __kprobes void FETCH_FUNC_NAME(stack, type)(struct pt_regs *regs,\
- void *offset, void *dest) \
+static void FETCH_FUNC_NAME(stack, type)(struct pt_regs *regs, \
+ void *offset, void *dest) \
{ \
*(type *)dest = (type)regs_get_kernel_stack_nth(regs, \
(unsigned int)((unsigned long)offset)); \
-}
+} \
+NOKPROBE_SYMBOL(FETCH_FUNC_NAME(stack, type));
DEFINE_BASIC_FETCH_FUNCS(stack)
/* No string on the stack entry */
#define fetch_stack_string NULL
#define fetch_stack_string_size NULL

#define DEFINE_FETCH_retval(type) \
-static __kprobes void FETCH_FUNC_NAME(retval, type)(struct pt_regs *regs,\
+static void FETCH_FUNC_NAME(retval, type)(struct pt_regs *regs, \
void *dummy, void *dest) \
{ \
*(type *)dest = (type)regs_return_value(regs); \
-}
+} \
+NOKPROBE_SYMBOL(FETCH_FUNC_NAME(retval, type));
DEFINE_BASIC_FETCH_FUNCS(retval)
/* No string on the retval */
#define fetch_retval_string NULL
#define fetch_retval_string_size NULL

#define DEFINE_FETCH_memory(type) \
-static __kprobes void FETCH_FUNC_NAME(memory, type)(struct pt_regs *regs,\
+static void FETCH_FUNC_NAME(memory, type)(struct pt_regs *regs, \
void *addr, void *dest) \
{ \
type retval; \
@@ -154,14 +159,15 @@ static __kprobes void FETCH_FUNC_NAME(memory, type)(struct pt_regs *regs,\
*(type *)dest = 0; \
else \
*(type *)dest = retval; \
-}
+} \
+NOKPROBE_SYMBOL(FETCH_FUNC_NAME(memory, type));
DEFINE_BASIC_FETCH_FUNCS(memory)
/*
* Fetch a null-terminated string. Caller MUST set *(u32 *)dest with max
* length and relative data location.
*/
-static __kprobes void FETCH_FUNC_NAME(memory, string)(struct pt_regs *regs,
- void *addr, void *dest)
+static void FETCH_FUNC_NAME(memory, string)(struct pt_regs *regs,
+ void *addr, void *dest)
{
long ret;
int maxlen = get_rloc_len(*(u32 *)dest);
@@ -195,10 +201,11 @@ static __kprobes void FETCH_FUNC_NAME(memory, string)(struct pt_regs *regs,
get_rloc_offs(*(u32 *)dest));
}
}
+NOKPROBE_SYMBOL(FETCH_FUNC_NAME(memory, string));

/* Return the length of string -- including null terminal byte */
-static __kprobes void FETCH_FUNC_NAME(memory, string_size)(struct pt_regs *regs,
- void *addr, void *dest)
+static void FETCH_FUNC_NAME(memory, string_size)(struct pt_regs *regs,
+ void *addr, void *dest)
{
mm_segment_t old_fs;
int ret, len = 0;
@@ -221,6 +228,7 @@ static __kprobes void FETCH_FUNC_NAME(memory, string_size)(struct pt_regs *regs,
else
*(u32 *)dest = len;
}
+NOKPROBE_SYMBOL(FETCH_FUNC_NAME(memory, string_size));

/* Memory fetching by symbol */
struct symbol_cache {
@@ -268,7 +276,7 @@ static struct symbol_cache *alloc_symbol_cache(const char *sym, long offset)
}

#define DEFINE_FETCH_symbol(type) \
-static __kprobes void FETCH_FUNC_NAME(symbol, type)(struct pt_regs *regs,\
+static void FETCH_FUNC_NAME(symbol, type)(struct pt_regs *regs, \
void *data, void *dest) \
{ \
struct symbol_cache *sc = data; \
@@ -276,7 +284,8 @@ static __kprobes void FETCH_FUNC_NAME(symbol, type)(struct pt_regs *regs,\
fetch_memory_##type(regs, (void *)sc->addr, dest); \
else \
*(type *)dest = 0; \
-}
+} \
+NOKPROBE_SYMBOL(FETCH_FUNC_NAME(symbol, type));
DEFINE_BASIC_FETCH_FUNCS(symbol)
DEFINE_FETCH_symbol(string)
DEFINE_FETCH_symbol(string_size)
@@ -288,7 +297,7 @@ struct deref_fetch_param {
};

#define DEFINE_FETCH_deref(type) \
-static __kprobes void FETCH_FUNC_NAME(deref, type)(struct pt_regs *regs,\
+static void FETCH_FUNC_NAME(deref, type)(struct pt_regs *regs, \
void *data, void *dest) \
{ \
struct deref_fetch_param *dprm = data; \
@@ -299,20 +308,22 @@ static __kprobes void FETCH_FUNC_NAME(deref, type)(struct pt_regs *regs,\
fetch_memory_##type(regs, (void *)addr, dest); \
} else \
*(type *)dest = 0; \
-}
+} \
+NOKPROBE_SYMBOL(FETCH_FUNC_NAME(deref, type));
DEFINE_BASIC_FETCH_FUNCS(deref)
DEFINE_FETCH_deref(string)
DEFINE_FETCH_deref(string_size)

-static __kprobes void update_deref_fetch_param(struct deref_fetch_param *data)
+static void update_deref_fetch_param(struct deref_fetch_param *data)
{
if (CHECK_FETCH_FUNCS(deref, data->orig.fn))
update_deref_fetch_param(data->orig.data);
else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn))
update_symbol_cache(data->orig.data);
}
+NOKPROBE_SYMBOL(update_deref_fetch_param);

-static __kprobes void free_deref_fetch_param(struct deref_fetch_param *data)
+static void free_deref_fetch_param(struct deref_fetch_param *data)
{
if (CHECK_FETCH_FUNCS(deref, data->orig.fn))
free_deref_fetch_param(data->orig.data);
@@ -320,6 +331,7 @@ static __kprobes void free_deref_fetch_param(struct deref_fetch_param *data)
free_symbol_cache(data->orig.data);
kfree(data);
}
+NOKPROBE_SYMBOL(free_deref_fetch_param);

/* Bitfield fetch function */
struct bitfield_fetch_param {
@@ -329,7 +341,7 @@ struct bitfield_fetch_param {
};

#define DEFINE_FETCH_bitfield(type) \
-static __kprobes void FETCH_FUNC_NAME(bitfield, type)(struct pt_regs *regs,\
+static void FETCH_FUNC_NAME(bitfield, type)(struct pt_regs *regs, \
void *data, void *dest) \
{ \
struct bitfield_fetch_param *bprm = data; \
@@ -340,8 +352,8 @@ static __kprobes void FETCH_FUNC_NAME(bitfield, type)(struct pt_regs *regs,\
buf >>= bprm->low_shift; \
} \
*(type *)dest = buf; \
-}
-
+} \
+NOKPROBE_SYMBOL(FETCH_FUNC_NAME(bitfield, type));
DEFINE_BASIC_FETCH_FUNCS(bitfield)
#define fetch_bitfield_string NULL
#define fetch_bitfield_string_size NULL
@@ -467,11 +479,11 @@ fail:
}

/* Special function : only accept unsigned long */
-static __kprobes void fetch_stack_address(struct pt_regs *regs,
- void *dummy, void *dest)
+static void fetch_stack_address(struct pt_regs *regs, void *dummy, void *dest)
{
*(unsigned long *)dest = kernel_stack_pointer(regs);
}
+NOKPROBE_SYMBOL(fetch_stack_address);

static fetch_func_t get_fetch_size_function(const struct fetch_type *type,
fetch_func_t orig_fn)
diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h
index 5c7e09d..72250cb 100644
--- a/kernel/trace/trace_probe.h
+++ b/kernel/trace/trace_probe.h
@@ -124,8 +124,8 @@ struct probe_arg {
const struct fetch_type *type; /* Type of this argument */
};

-static inline __kprobes void call_fetch(struct fetch_param *fprm,
- struct pt_regs *regs, void *dest)
+static __always_inline void call_fetch(struct fetch_param *fprm,
+ struct pt_regs *regs, void *dest)
{
return fprm->fn(regs, fprm->data, dest);
}


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