[PATCH -tip 1/4] tracing/kprobes: Support "string" type

From: Masami Hiramatsu
Date: Mon May 17 2010 - 22:44:58 EST

Support string type tracing and printing in kprobe-tracer.
This allows user to trace string data in kernel including
__user data. Note that sometimes __user data may not be
accessed if it is paged-out (sorry, but kprobes operation
should be done in atomic, we can not wait for page-in).

Signed-off-by: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
Cc: Paul Mackerras <paulus@xxxxxxxxx>
Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Mike Galbraith <efault@xxxxxx>
Cc: Frederic Weisbecker <fweisbec@xxxxxxxxx>
---

Documentation/trace/kprobetrace.txt | 2
kernel/trace/trace_kprobe.c | 356 +++++++++++++++++++++++++++--------
2 files changed, 279 insertions(+), 79 deletions(-)

diff --git a/Documentation/trace/kprobetrace.txt b/Documentation/trace/kprobetrace.txt
index ec94748..5f77d94 100644
--- a/Documentation/trace/kprobetrace.txt
+++ b/Documentation/trace/kprobetrace.txt
@@ -42,7 +42,7 @@ Synopsis of kprobe_events
+|-offs(FETCHARG) : Fetch memory at FETCHARG +|- offs address.(**)
NAME=FETCHARG : Set NAME as the argument name of FETCHARG.
FETCHARG:TYPE : Set TYPE as the type of FETCHARG. Currently, basic types
- (u8/u16/u32/u64/s8/s16/s32/s64) are supported.
+ (u8/u16/u32/u64/s8/s16/s32/s64) and string are supported.

(*) only for return probe.
(**) this is useful for fetching a field of data structures.
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index a751432..43bcdf3 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -30,6 +30,8 @@
#include <linux/ptrace.h>
#include <linux/perf_event.h>
#include <linux/stringify.h>
+#include <linux/limits.h>
+#include <linux/uaccess.h>
#include <asm/bitsperlong.h>

#include "trace.h"
@@ -38,6 +40,7 @@
#define MAX_TRACE_ARGS 128
#define MAX_ARGSTR_LEN 63
#define MAX_EVENT_NAME_LEN 64
+#define MAX_STRING_SIZE PATH_MAX
#define KPROBE_EVENT_SYSTEM "kprobes"

/* Reserved field names */
@@ -58,14 +61,16 @@ const char *reserved_field_names[] = {
};

/* Printing function type */
-typedef int (*print_type_func_t)(struct trace_seq *, const char *, void *);
+typedef int (*print_type_func_t)(struct trace_seq *, const char *, void *,
+ void *);
#define PRINT_TYPE_FUNC_NAME(type) print_type_##type
#define PRINT_TYPE_FMT_NAME(type) print_type_format_##type

/* 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)\
+ const char *name, \
+ void *data, void *ent)\
{ \
return trace_seq_printf(s, " %s=" fmt, name, (cast)*(type *)data);\
} \
@@ -80,6 +85,41 @@ DEFINE_BASIC_PRINT_TYPE_FUNC(s16, "%d", int)
DEFINE_BASIC_PRINT_TYPE_FUNC(s32, "%ld", long)
DEFINE_BASIC_PRINT_TYPE_FUNC(s64, "%lld", long long)

+typedef u32 data_rloc_t; /* Data relative location */
+#define make_data_rloc(len, roffs) \
+ (data_rloc_t)(((u32)(len) << 16) | ((u32)(roffs) & 0xffff))
+#define get_rloc_len(dl) ((data_rloc_t)(dl) >> 16)
+#define get_rloc_offs(dl) ((data_rloc_t)(dl) & 0xffff)
+static inline void *get_rloc_data(data_rloc_t *dl)
+{
+ return (u8 *)dl + get_rloc_offs(*dl);
+}
+/* For data_loc conversion */
+static inline void *get_loc_data(u32 *dl, void *ent)
+{
+ return (u8 *)ent + get_rloc_offs(*dl);
+}
+#define convert_rloc_to_loc(dl, offs) ((data_rloc_t)(dl) + (offs))
+
+/* For defining macros */
+typedef data_rloc_t string;
+typedef data_rloc_t 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)
+{
+ int len = *(u32 *)data >> 16;
+
+ if (!len)
+ return trace_seq_printf(s, " %s=(fault)", name);
+ else
+ return trace_seq_printf(s, " %s=\"%s\"", name,
+ (const char *)get_loc_data(data, ent));
+}
+static const char PRINT_TYPE_FMT_NAME(string)[] = "\\\"%s\\\"";
+
/* Data fetch function type */
typedef void (*fetch_func_t)(struct pt_regs *, void *, void *);

@@ -94,32 +134,38 @@ static __kprobes void call_fetch(struct fetch_param *fprm,
return fprm->fn(regs, fprm->data, dest);
}

-#define FETCH_FUNC_NAME(kind, type) fetch_##kind##_##type
+#define FETCH_FUNC_NAME(method, type) fetch_##method##_##type
/*
* Define macro for basic types - we don't need to define s* types, because
* we have to care only about bitwidth at recording time.
*/
-#define DEFINE_BASIC_FETCH_FUNCS(kind) \
-DEFINE_FETCH_##kind(u8) \
-DEFINE_FETCH_##kind(u16) \
-DEFINE_FETCH_##kind(u32) \
-DEFINE_FETCH_##kind(u64)
-
-#define CHECK_BASIC_FETCH_FUNCS(kind, fn) \
- ((FETCH_FUNC_NAME(kind, u8) == fn) || \
- (FETCH_FUNC_NAME(kind, u16) == fn) || \
- (FETCH_FUNC_NAME(kind, u32) == fn) || \
- (FETCH_FUNC_NAME(kind, u64) == fn))
+#define DEFINE_BASIC_FETCH_FUNCS(method) \
+DEFINE_FETCH_##method(u8) \
+DEFINE_FETCH_##method(u16) \
+DEFINE_FETCH_##method(u32) \
+DEFINE_FETCH_##method(u64)
+
+#define CHECK_FETCH_FUNCS(method, fn) \
+ (((FETCH_FUNC_NAME(method, u8) == fn) || \
+ (FETCH_FUNC_NAME(method, u16) == fn) || \
+ (FETCH_FUNC_NAME(method, u32) == fn) || \
+ (FETCH_FUNC_NAME(method, u64) == fn) || \
+ (FETCH_FUNC_NAME(method, string) == fn) || \
+ (FETCH_FUNC_NAME(method, string_size) == fn)) \
+ && (fn != NULL))

/* Data fetch function templates */
#define DEFINE_FETCH_reg(type) \
static __kprobes void FETCH_FUNC_NAME(reg, type)(struct pt_regs *regs, \
- void *offset, void *dest) \
+ void *offset, void *dest) \
{ \
*(type *)dest = (type)regs_get_register(regs, \
(unsigned int)((unsigned long)offset)); \
}
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,\
@@ -129,6 +175,9 @@ static __kprobes void FETCH_FUNC_NAME(stack, type)(struct pt_regs *regs,\
(unsigned int)((unsigned long)offset)); \
}
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,\
@@ -137,6 +186,9 @@ static __kprobes void FETCH_FUNC_NAME(retval, type)(struct pt_regs *regs,\
*(type *)dest = (type)regs_return_value(regs); \
}
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,\
@@ -149,6 +201,63 @@ static __kprobes void FETCH_FUNC_NAME(memory, type)(struct pt_regs *regs,\
*(type *)dest = retval; \
}
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)
+{
+ long ret;
+ int maxlen = get_rloc_len(*(data_rloc_t *)dest);
+ u8 *dst = get_rloc_data(dest);
+ u8 *src = addr;
+ mm_segment_t old_fs = get_fs();
+ if (!maxlen)
+ return;
+ /*
+ * Try to get string again, since the string can be changed while
+ * probing.
+ */
+ set_fs(KERNEL_DS);
+ pagefault_disable();
+ do
+ ret = __copy_from_user_inatomic(dst++, src++, 1);
+ while (dst[-1] && ret == 0 && src - (u8 *)addr < maxlen);
+ dst[-1] = '\0';
+ pagefault_enable();
+ set_fs(old_fs);
+
+ if (ret < 0) { /* Failed to fetch string */
+ ((u8 *)get_rloc_data(dest))[0] = '\0';
+ *(data_rloc_t *)dest = make_data_rloc(0,
+ get_rloc_offs(*(data_rloc_t *)dest));
+ } else
+ *(data_rloc_t *)dest = make_data_rloc(src - (u8 *)addr,
+ get_rloc_offs(*(data_rloc_t *)dest));
+}
+/* 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)
+{
+ int ret, len = 0;
+ u8 c;
+ mm_segment_t old_fs = get_fs();
+
+ set_fs(KERNEL_DS);
+ pagefault_disable();
+ do {
+ ret = __copy_from_user_inatomic(&c, (u8 *)addr + len, 1);
+ len++;
+ } while (c && ret == 0 && len < MAX_STRING_SIZE);
+ pagefault_enable();
+ set_fs(old_fs);
+
+ if (ret < 0) /* Failed to check the length */
+ *(u32 *)dest = 0;
+ else
+ *(u32 *)dest = len;
+}

/* Memory fetching by symbol */
struct symbol_cache {
@@ -203,6 +312,8 @@ static __kprobes void FETCH_FUNC_NAME(symbol, type)(struct pt_regs *regs,\
*(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 {
@@ -224,12 +335,14 @@ static __kprobes void FETCH_FUNC_NAME(deref, type)(struct pt_regs *regs,\
*(type *)dest = 0; \
}
DEFINE_BASIC_FETCH_FUNCS(deref)
+DEFINE_FETCH_deref(string)
+DEFINE_FETCH_deref(string_size)

static __kprobes void free_deref_fetch_param(struct deref_fetch_param *data)
{
- if (CHECK_BASIC_FETCH_FUNCS(deref, data->orig.fn))
+ if (CHECK_FETCH_FUNCS(deref, data->orig.fn))
free_deref_fetch_param(data->orig.data);
- else if (CHECK_BASIC_FETCH_FUNCS(symbol, data->orig.fn))
+ else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn))
free_symbol_cache(data->orig.data);
kfree(data);
}
@@ -240,23 +353,43 @@ static __kprobes void free_deref_fetch_param(struct deref_fetch_param *data)
#define DEFAULT_FETCH_TYPE _DEFAULT_FETCH_TYPE(BITS_PER_LONG)
#define DEFAULT_FETCH_TYPE_STR __stringify(DEFAULT_FETCH_TYPE)

-#define ASSIGN_FETCH_FUNC(kind, type) \
- .kind = FETCH_FUNC_NAME(kind, type)
-
-#define ASSIGN_FETCH_TYPE(ptype, ftype, sign) \
- {.name = #ptype, \
- .size = sizeof(ftype), \
- .is_signed = sign, \
- .print = PRINT_TYPE_FUNC_NAME(ptype), \
- .fmt = PRINT_TYPE_FMT_NAME(ptype), \
-ASSIGN_FETCH_FUNC(reg, ftype), \
-ASSIGN_FETCH_FUNC(stack, ftype), \
-ASSIGN_FETCH_FUNC(retval, ftype), \
-ASSIGN_FETCH_FUNC(memory, ftype), \
-ASSIGN_FETCH_FUNC(symbol, ftype), \
-ASSIGN_FETCH_FUNC(deref, ftype), \
+/* Fetch types */
+enum {
+ FETCH_MTD_reg = 0,
+ FETCH_MTD_stack,
+ FETCH_MTD_retval,
+ FETCH_MTD_memory,
+ FETCH_MTD_symbol,
+ FETCH_MTD_deref,
+ FETCH_MTD_END,
+};
+
+#define ASSIGN_FETCH_FUNC(method, type) \
+ [FETCH_MTD_##method] = FETCH_FUNC_NAME(method, type)
+
+#define __ASSIGN_FETCH_TYPE(_name, ptype, ftype, _size, sign, _fmttype) \
+ {.name = _name, \
+ .size = _size, \
+ .is_signed = sign, \
+ .print = PRINT_TYPE_FUNC_NAME(ptype), \
+ .fmt = PRINT_TYPE_FMT_NAME(ptype), \
+ .fmttype = _fmttype, \
+ .fetch = { \
+ASSIGN_FETCH_FUNC(reg, ftype), \
+ASSIGN_FETCH_FUNC(stack, ftype), \
+ASSIGN_FETCH_FUNC(retval, ftype), \
+ASSIGN_FETCH_FUNC(memory, ftype), \
+ASSIGN_FETCH_FUNC(symbol, ftype), \
+ASSIGN_FETCH_FUNC(deref, ftype), \
+ } \
}

+#define ASSIGN_FETCH_TYPE(ptype, ftype, sign) \
+ __ASSIGN_FETCH_TYPE(#ptype, ptype, ftype, sizeof(ftype), sign, #ptype)
+
+#define FETCH_TYPE_STRING 0
+#define FETCH_TYPE_STRSIZE 1
+
/* Fetch type information table */
static const struct fetch_type {
const char *name; /* Name of type */
@@ -264,14 +397,16 @@ static const struct fetch_type {
int is_signed; /* Signed flag */
print_type_func_t print; /* Print functions */
const char *fmt; /* Fromat string */
+ const char *fmttype; /* Name in format file */
/* Fetch functions */
- fetch_func_t reg;
- fetch_func_t stack;
- fetch_func_t retval;
- fetch_func_t memory;
- fetch_func_t symbol;
- fetch_func_t deref;
+ fetch_func_t fetch[FETCH_MTD_END];
} fetch_type_table[] = {
+ /* Special types */
+ [FETCH_TYPE_STRING] = __ASSIGN_FETCH_TYPE("string", string, string,
+ sizeof(u32), 1, "__data_loc char[]"),
+ [FETCH_TYPE_STRSIZE] = __ASSIGN_FETCH_TYPE("string_size", u32,
+ string_size, sizeof(u32), 0, "u32"),
+ /* Basic types */
ASSIGN_FETCH_TYPE(u8, u8, 0),
ASSIGN_FETCH_TYPE(u16, u16, 0),
ASSIGN_FETCH_TYPE(u32, u32, 0),
@@ -302,12 +437,28 @@ static __kprobes void fetch_stack_address(struct pt_regs *regs,
*(unsigned long *)dest = kernel_stack_pointer(regs);
}

+static fetch_func_t get_fetch_size_function(const struct fetch_type *type,
+ fetch_func_t orig_fn)
+{
+ int i;
+
+ if (type != &fetch_type_table[FETCH_TYPE_STRING])
+ return NULL; /* Only string type needs size function */
+ for (i = 0; i < FETCH_MTD_END; i++)
+ if (type->fetch[i] == orig_fn)
+ return fetch_type_table[FETCH_TYPE_STRSIZE].fetch[i];
+
+ WARN_ON(1); /* This should not happen */
+ return NULL;
+}
+
/**
* Kprobe event core functions
*/

struct probe_arg {
struct fetch_param fetch;
+ struct fetch_param fetch_size;
unsigned int offset; /* Offset from argument entry */
const char *name; /* Name of this argument */
const char *comm; /* Command of this argument */
@@ -428,9 +579,9 @@ error:

static void free_probe_arg(struct probe_arg *arg)
{
- if (CHECK_BASIC_FETCH_FUNCS(deref, arg->fetch.fn))
+ if (CHECK_FETCH_FUNCS(deref, arg->fetch.fn))
free_deref_fetch_param(arg->fetch.data);
- else if (CHECK_BASIC_FETCH_FUNCS(symbol, arg->fetch.fn))
+ else if (CHECK_FETCH_FUNCS(symbol, arg->fetch.fn))
free_symbol_cache(arg->fetch.data);
kfree(arg->name);
kfree(arg->comm);
@@ -547,7 +698,7 @@ static int parse_probe_vars(char *arg, const struct fetch_type *t,

if (strcmp(arg, "retval") == 0) {
if (is_return)
- f->fn = t->retval;
+ f->fn = t->fetch[FETCH_MTD_retval];
else
ret = -EINVAL;
} else if (strncmp(arg, "stack", 5) == 0) {
@@ -561,7 +712,7 @@ static int parse_probe_vars(char *arg, const struct fetch_type *t,
if (ret || param > PARAM_MAX_STACK)
ret = -EINVAL;
else {
- f->fn = t->stack;
+ f->fn = t->fetch[FETCH_MTD_stack];
f->data = (void *)param;
}
} else
@@ -587,7 +738,7 @@ static int __parse_probe_arg(char *arg, const struct fetch_type *t,
case '%': /* named register */
ret = regs_query_register_offset(arg + 1);
if (ret >= 0) {
- f->fn = t->reg;
+ f->fn = t->fetch[FETCH_MTD_reg];
f->data = (void *)(unsigned long)ret;
ret = 0;
}
@@ -597,7 +748,7 @@ static int __parse_probe_arg(char *arg, const struct fetch_type *t,
ret = strict_strtoul(arg + 1, 0, &param);
if (ret)
break;
- f->fn = t->memory;
+ f->fn = t->fetch[FETCH_MTD_memory];
f->data = (void *)param;
} else {
ret = split_symbol_offset(arg + 1, &offset);
@@ -605,7 +756,7 @@ static int __parse_probe_arg(char *arg, const struct fetch_type *t,
break;
f->data = alloc_symbol_cache(arg + 1, offset);
if (f->data)
- f->fn = t->symbol;
+ f->fn = t->fetch[FETCH_MTD_symbol];
}
break;
case '+': /* deref memory */
@@ -635,14 +786,17 @@ static int __parse_probe_arg(char *arg, const struct fetch_type *t,
if (ret)
kfree(dprm);
else {
- f->fn = t->deref;
+ f->fn = t->fetch[FETCH_MTD_deref];
f->data = (void *)dprm;
}
}
break;
}
- if (!ret && !f->fn)
+ if (!ret && !f->fn) { /* Parsed, but do not find fetch method */
+ pr_info("%s type has no corresponding fetch method.\n",
+ t->name);
ret = -EINVAL;
+ }
return ret;
}

@@ -651,6 +805,7 @@ static int parse_probe_arg(char *arg, struct trace_probe *tp,
struct probe_arg *parg, int is_return)
{
const char *t;
+ int ret;

if (strlen(arg) > MAX_ARGSTR_LEN) {
pr_info("Argument is too long.: %s\n", arg);
@@ -673,7 +828,13 @@ static int parse_probe_arg(char *arg, struct trace_probe *tp,
}
parg->offset = tp->size;
tp->size += parg->type->size;
- return __parse_probe_arg(arg, parg->type, &parg->fetch, is_return);
+ ret = __parse_probe_arg(arg, parg->type, &parg->fetch, is_return);
+ if (ret >= 0) {
+ parg->fetch_size.fn = get_fetch_size_function(parg->type,
+ parg->fetch.fn);
+ parg->fetch_size.data = parg->fetch.data;
+ }
+ return ret;
}

/* Return 1 if name is reserved or already used by another argument */
@@ -1042,6 +1203,47 @@ static const struct file_operations kprobe_profile_ops = {
.release = seq_release,
};

+/* Sum up total data length for dynamic arraies (strings) */
+static __kprobes int __get_data_size(struct trace_probe *tp,
+ struct pt_regs *regs)
+{
+ int i, ret = 0;
+ u32 len;
+
+ for (i = 0; i < tp->nr_args; i++)
+ if (unlikely(tp->args[i].fetch_size.fn)) {
+ call_fetch(&tp->args[i].fetch_size, regs, &len);
+ ret += len;
+ }
+
+ return ret;
+}
+
+/* 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)
+{
+ int i;
+ u32 end = tp->size;
+ data_rloc_t *dl;
+
+ for (i = 0; i < tp->nr_args; i++) {
+ if (unlikely(tp->args[i].fetch_size.fn)) {
+ dl = (data_rloc_t *)(data + tp->args[i].offset);
+ *dl = make_data_rloc(maxlen, end - tp->args[i].offset);
+ call_fetch(&tp->args[i].fetch, regs, dl);
+ end += get_rloc_len(*dl);
+ maxlen -= get_rloc_len(*dl);
+ /* Trick here, convert data_rloc to data_loc */
+ *dl = convert_rloc_to_loc(*dl,
+ ent_size + tp->args[i].offset);
+ } else
+ call_fetch(&tp->args[i].fetch, regs,
+ data + tp->args[i].offset);
+ }
+}
+
/* Kprobe handler */
static __kprobes void kprobe_trace_func(struct kprobe *kp, struct pt_regs *regs)
{
@@ -1049,8 +1251,7 @@ static __kprobes void kprobe_trace_func(struct kprobe *kp, struct pt_regs *regs)
struct kprobe_trace_entry_head *entry;
struct ring_buffer_event *event;
struct ring_buffer *buffer;
- u8 *data;
- int size, i, pc;
+ int size, dsize, pc;
unsigned long irq_flags;
struct ftrace_event_call *call = &tp->call;

@@ -1059,7 +1260,8 @@ static __kprobes void kprobe_trace_func(struct kprobe *kp, struct pt_regs *regs)
local_save_flags(irq_flags);
pc = preempt_count();

- size = sizeof(*entry) + tp->size;
+ dsize = __get_data_size(tp, regs);
+ size = sizeof(*entry) + tp->size + dsize;

event = trace_current_buffer_lock_reserve(&buffer, call->id, size,
irq_flags, pc);
@@ -1068,9 +1270,7 @@ static __kprobes void kprobe_trace_func(struct kprobe *kp, struct pt_regs *regs)

entry = ring_buffer_event_data(event);
entry->ip = (unsigned long)kp->addr;
- data = (u8 *)&entry[1];
- for (i = 0; i < tp->nr_args; i++)
- call_fetch(&tp->args[i].fetch, regs, data + tp->args[i].offset);
+ store_trace_args(sizeof(*entry), tp, regs, (u8 *)&entry[1], dsize);

if (!filter_current_check_discard(buffer, call, entry, event))
trace_nowake_buffer_unlock_commit(buffer, event, irq_flags, pc);
@@ -1084,15 +1284,15 @@ static __kprobes void kretprobe_trace_func(struct kretprobe_instance *ri,
struct kretprobe_trace_entry_head *entry;
struct ring_buffer_event *event;
struct ring_buffer *buffer;
- u8 *data;
- int size, i, pc;
+ int size, pc, dsize;
unsigned long irq_flags;
struct ftrace_event_call *call = &tp->call;

local_save_flags(irq_flags);
pc = preempt_count();

- size = sizeof(*entry) + tp->size;
+ dsize = __get_data_size(tp, regs);
+ size = sizeof(*entry) + tp->size + dsize;

event = trace_current_buffer_lock_reserve(&buffer, call->id, size,
irq_flags, pc);
@@ -1102,9 +1302,7 @@ static __kprobes void kretprobe_trace_func(struct kretprobe_instance *ri,
entry = ring_buffer_event_data(event);
entry->func = (unsigned long)tp->rp.kp.addr;
entry->ret_ip = (unsigned long)ri->ret_addr;
- data = (u8 *)&entry[1];
- for (i = 0; i < tp->nr_args; i++)
- call_fetch(&tp->args[i].fetch, regs, data + tp->args[i].offset);
+ store_trace_args(sizeof(*entry), tp, regs, (u8 *)&entry[1], dsize);

if (!filter_current_check_discard(buffer, call, entry, event))
trace_nowake_buffer_unlock_commit(buffer, event, irq_flags, pc);
@@ -1137,7 +1335,7 @@ print_kprobe_event(struct trace_iterator *iter, int flags)
data = (u8 *)&field[1];
for (i = 0; i < tp->nr_args; i++)
if (!tp->args[i].type->print(s, tp->args[i].name,
- data + tp->args[i].offset))
+ data + tp->args[i].offset, field))
goto partial;

if (!trace_seq_puts(s, "\n"))
@@ -1180,7 +1378,7 @@ print_kretprobe_event(struct trace_iterator *iter, int flags)
data = (u8 *)&field[1];
for (i = 0; i < tp->nr_args; i++)
if (!tp->args[i].type->print(s, tp->args[i].name,
- data + tp->args[i].offset))
+ data + tp->args[i].offset, field))
goto partial;

if (!trace_seq_puts(s, "\n"))
@@ -1242,7 +1440,7 @@ static int kprobe_event_define_fields(struct ftrace_event_call *event_call)
DEFINE_FIELD(unsigned long, ip, FIELD_STRING_IP, 0);
/* Set argument names as fields */
for (i = 0; i < tp->nr_args; i++) {
- ret = trace_define_field(event_call, tp->args[i].type->name,
+ ret = trace_define_field(event_call, tp->args[i].type->fmttype,
tp->args[i].name,
sizeof(field) + tp->args[i].offset,
tp->args[i].type->size,
@@ -1264,7 +1462,7 @@ static int kretprobe_event_define_fields(struct ftrace_event_call *event_call)
DEFINE_FIELD(unsigned long, ret_ip, FIELD_STRING_RETIP, 0);
/* Set argument names as fields */
for (i = 0; i < tp->nr_args; i++) {
- ret = trace_define_field(event_call, tp->args[i].type->name,
+ ret = trace_define_field(event_call, tp->args[i].type->fmttype,
tp->args[i].name,
sizeof(field) + tp->args[i].offset,
tp->args[i].type->size,
@@ -1304,8 +1502,13 @@ static int __set_print_fmt(struct trace_probe *tp, char *buf, int len)
pos += snprintf(buf + pos, LEN_OR_ZERO, "\", %s", arg);

for (i = 0; i < tp->nr_args; i++) {
- pos += snprintf(buf + pos, LEN_OR_ZERO, ", REC->%s",
- tp->args[i].name);
+ if (strcmp(tp->args[i].type->name, "string") == 0)
+ pos += snprintf(buf + pos, LEN_OR_ZERO,
+ ", __get_str(%s)",
+ tp->args[i].name);
+ else
+ pos += snprintf(buf + pos, LEN_OR_ZERO, ", REC->%s",
+ tp->args[i].name);
}

#undef LEN_OR_ZERO
@@ -1341,12 +1544,12 @@ static __kprobes void kprobe_perf_func(struct kprobe *kp,
struct trace_probe *tp = container_of(kp, struct trace_probe, rp.kp);
struct ftrace_event_call *call = &tp->call;
struct kprobe_trace_entry_head *entry;
- u8 *data;
- int size, __size, i;
+ int size, __size, dsize;
unsigned long irq_flags;
int rctx;

- __size = sizeof(*entry) + tp->size;
+ dsize = __get_data_size(tp, regs);
+ __size = sizeof(*entry) + tp->size + dsize;
size = ALIGN(__size + sizeof(u32), sizeof(u64));
size -= sizeof(u32);
if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE,
@@ -1358,9 +1561,8 @@ static __kprobes void kprobe_perf_func(struct kprobe *kp,
return;

entry->ip = (unsigned long)kp->addr;
- data = (u8 *)&entry[1];
- for (i = 0; i < tp->nr_args; i++)
- call_fetch(&tp->args[i].fetch, regs, data + tp->args[i].offset);
+ memset(&entry[1], 0, dsize);
+ store_trace_args(sizeof(*entry), tp, regs, (u8 *)&entry[1], dsize);

perf_trace_buf_submit(entry, size, rctx, entry->ip, 1, irq_flags, regs);
}
@@ -1372,12 +1574,12 @@ static __kprobes void kretprobe_perf_func(struct kretprobe_instance *ri,
struct trace_probe *tp = container_of(ri->rp, struct trace_probe, rp);
struct ftrace_event_call *call = &tp->call;
struct kretprobe_trace_entry_head *entry;
- u8 *data;
- int size, __size, i;
+ int size, __size, dsize;
unsigned long irq_flags;
int rctx;

- __size = sizeof(*entry) + tp->size;
+ dsize = __get_data_size(tp, regs);
+ __size = sizeof(*entry) + tp->size + dsize;
size = ALIGN(__size + sizeof(u32), sizeof(u64));
size -= sizeof(u32);
if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE,
@@ -1390,9 +1592,7 @@ static __kprobes void kretprobe_perf_func(struct kretprobe_instance *ri,

entry->func = (unsigned long)tp->rp.kp.addr;
entry->ret_ip = (unsigned long)ri->ret_addr;
- data = (u8 *)&entry[1];
- for (i = 0; i < tp->nr_args; i++)
- call_fetch(&tp->args[i].fetch, regs, data + tp->args[i].offset);
+ store_trace_args(sizeof(*entry), tp, regs, (u8 *)&entry[1], dsize);

perf_trace_buf_submit(entry, size, rctx, entry->ret_ip, 1,
irq_flags, regs);


--
Masami Hiramatsu
e-mail: mhiramat@xxxxxxxxxx
--
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