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kprobes, ftrace: Use NOKPROBE_SYMBOL macro in ftrace
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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.

Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20140417081828.26341.55152.stgit@ltc230.yrl.intra.hitachi.co.jp
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Masami Hiramatsu authored and Ingo Molnar committed Apr 24, 2014
1 parent 820aede commit 3da0f18
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Showing 4 changed files with 82 additions and 65 deletions.
5 changes: 3 additions & 2 deletions kernel/trace/trace_event_perf.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -248,8 +248,8 @@ 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;
Expand Down Expand Up @@ -281,6 +281,7 @@ __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
Expand Down
66 changes: 39 additions & 27 deletions kernel/trace/trace_kprobe.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -40,35 +40,35 @@ struct trace_kprobe {
(sizeof(struct probe_arg) * (n)))


static __kprobes bool trace_kprobe_is_return(struct trace_kprobe *tk)
static nokprobe_inline bool trace_kprobe_is_return(struct trace_kprobe *tk)
{
return tk->rp.handler != NULL;
}

static __kprobes const char *trace_kprobe_symbol(struct trace_kprobe *tk)
static nokprobe_inline const char *trace_kprobe_symbol(struct trace_kprobe *tk)
{
return tk->symbol ? tk->symbol : "unknown";
}

static __kprobes unsigned long trace_kprobe_offset(struct trace_kprobe *tk)
static nokprobe_inline unsigned long trace_kprobe_offset(struct trace_kprobe *tk)
{
return tk->rp.kp.offset;
}

static __kprobes bool trace_kprobe_has_gone(struct trace_kprobe *tk)
static nokprobe_inline bool trace_kprobe_has_gone(struct trace_kprobe *tk)
{
return !!(kprobe_gone(&tk->rp.kp));
}

static __kprobes bool trace_kprobe_within_module(struct trace_kprobe *tk,
static nokprobe_inline bool trace_kprobe_within_module(struct trace_kprobe *tk,
struct module *mod)
{
int len = strlen(mod->name);
const char *name = trace_kprobe_symbol(tk);
return strncmp(mod->name, name, len) == 0 && name[len] == ':';
}

static __kprobes bool trace_kprobe_is_on_module(struct trace_kprobe *tk)
static nokprobe_inline bool trace_kprobe_is_on_module(struct trace_kprobe *tk)
{
return !!strchr(trace_kprobe_symbol(tk), ':');
}
Expand Down Expand Up @@ -132,34 +132,38 @@ struct symbol_cache *alloc_symbol_cache(const char *sym, long offset)
* Kprobes-specific fetch functions
*/
#define DEFINE_FETCH_stack(type) \
static __kprobes void FETCH_FUNC_NAME(stack, type)(struct pt_regs *regs,\
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_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; \
if (probe_kernel_address(addr, retval)) \
*(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);
Expand Down Expand Up @@ -193,10 +197,11 @@ 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;
Expand All @@ -219,17 +224,19 @@ 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));

#define DEFINE_FETCH_symbol(type) \
__kprobes void FETCH_FUNC_NAME(symbol, type)(struct pt_regs *regs, \
void *data, void *dest) \
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; \
}
} \
NOKPROBE_SYMBOL(FETCH_FUNC_NAME(symbol, type));

DEFINE_BASIC_FETCH_FUNCS(symbol)
DEFINE_FETCH_symbol(string)
DEFINE_FETCH_symbol(string_size)
Expand Down Expand Up @@ -907,7 +914,7 @@ static const struct file_operations kprobe_profile_ops = {
};

/* Kprobe handler */
static __kprobes void
static nokprobe_inline void
__kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs,
struct ftrace_event_file *ftrace_file)
{
Expand Down Expand Up @@ -943,17 +950,18 @@ __kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs,
entry, irq_flags, pc, regs);
}

static __kprobes void
static void
kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs)
{
struct event_file_link *link;

list_for_each_entry_rcu(link, &tk->tp.files, list)
__kprobe_trace_func(tk, regs, link->file);
}
NOKPROBE_SYMBOL(kprobe_trace_func);

/* Kretprobe handler */
static __kprobes void
static nokprobe_inline void
__kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri,
struct pt_regs *regs,
struct ftrace_event_file *ftrace_file)
Expand Down Expand Up @@ -991,7 +999,7 @@ __kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri,
entry, irq_flags, pc, regs);
}

static __kprobes void
static void
kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri,
struct pt_regs *regs)
{
Expand All @@ -1000,6 +1008,7 @@ kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri,
list_for_each_entry_rcu(link, &tk->tp.files, list)
__kretprobe_trace_func(tk, ri, regs, link->file);
}
NOKPROBE_SYMBOL(kretprobe_trace_func);

/* Event entry printers */
static enum print_line_t
Expand Down Expand Up @@ -1131,7 +1140,7 @@ static int kretprobe_event_define_fields(struct ftrace_event_call *event_call)
#ifdef CONFIG_PERF_EVENTS

/* Kprobe profile handler */
static __kprobes void
static void
kprobe_perf_func(struct trace_kprobe *tk, struct pt_regs *regs)
{
struct ftrace_event_call *call = &tk->tp.call;
Expand All @@ -1158,9 +1167,10 @@ kprobe_perf_func(struct trace_kprobe *tk, struct pt_regs *regs)
store_trace_args(sizeof(*entry), &tk->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_kprobe *tk, struct kretprobe_instance *ri,
struct pt_regs *regs)
{
Expand Down Expand Up @@ -1188,6 +1198,7 @@ kretprobe_perf_func(struct trace_kprobe *tk, struct kretprobe_instance *ri,
store_trace_args(sizeof(*entry), &tk->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 */

/*
Expand Down Expand Up @@ -1223,8 +1234,7 @@ static 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_kprobe *tk = container_of(kp, struct trace_kprobe, rp.kp);

Expand All @@ -1238,9 +1248,10 @@ 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
int kretprobe_dispatcher(struct kretprobe_instance *ri, struct pt_regs *regs)
static int
kretprobe_dispatcher(struct kretprobe_instance *ri, struct pt_regs *regs)
{
struct trace_kprobe *tk = container_of(ri->rp, struct trace_kprobe, rp);

Expand All @@ -1254,6 +1265,7 @@ 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
Expand Down
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