[PATCH -tip 4/7] trace/kprobes: Support basic types

From: Masami Hiramatsu
Date: Mon Mar 29 2010 - 16:31:38 EST

Support basic types of integer (u8, u16, u32, u64, s8, s16, s32, s64) in
kprobe tracer. With this patch, users can specify above basic types on
each arguments after ':'. If omitted, the argument type is set as
unsigned long (u32 or u64, arch-dependent).

e.g.
echo 'p account_system_time+0 hardirq_offset=%si:s32' > kprobe_events

adds a probe recording hardirq_offset in signed-32bits value on the
entry of account_system_time.

Signed-off-by: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxx>
Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
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 | 4
kernel/trace/trace.h | 16 -
kernel/trace/trace_kprobe.c | 535 ++++++++++++++++++++++-------------
3 files changed, 334 insertions(+), 221 deletions(-)

diff --git a/Documentation/trace/kprobetrace.txt b/Documentation/trace/kprobetrace.txt
index a9100b2..ec94748 100644
--- a/Documentation/trace/kprobetrace.txt
+++ b/Documentation/trace/kprobetrace.txt
@@ -40,7 +40,9 @@ Synopsis of kprobe_events
$stack : Fetch stack address.
$retval : Fetch return value.(*)
+|-offs(FETCHARG) : Fetch memory at FETCHARG +|- offs address.(**)
- NAME=FETCHARG: Set NAME as the argument name of FETCHARG.
+ 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.

(*) only for return probe.
(**) this is useful for fetching a field of data structures.
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index bec2c97..3ebdb6b 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -102,29 +102,17 @@ struct syscall_trace_exit {
long ret;
};

-struct kprobe_trace_entry {
+struct kprobe_trace_entry_head {
struct trace_entry ent;
unsigned long ip;
- int nargs;
- unsigned long args[];
};

-#define SIZEOF_KPROBE_TRACE_ENTRY(n) \
- (offsetof(struct kprobe_trace_entry, args) + \
- (sizeof(unsigned long) * (n)))
-
-struct kretprobe_trace_entry {
+struct kretprobe_trace_entry_head {
struct trace_entry ent;
unsigned long func;
unsigned long ret_ip;
- int nargs;
- unsigned long args[];
};

-#define SIZEOF_KRETPROBE_TRACE_ENTRY(n) \
- (offsetof(struct kretprobe_trace_entry, args) + \
- (sizeof(unsigned long) * (n)))
-
/*
* trace_flag_type is an enumeration that holds different
* states when a trace occurs. These are:
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index 1251e36..a751432 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -29,6 +29,8 @@
#include <linux/ctype.h>
#include <linux/ptrace.h>
#include <linux/perf_event.h>
+#include <linux/stringify.h>
+#include <asm/bitsperlong.h>

#include "trace.h"
#include "trace_output.h"
@@ -40,7 +42,6 @@

/* Reserved field names */
#define FIELD_STRING_IP "__probe_ip"
-#define FIELD_STRING_NARGS "__probe_nargs"
#define FIELD_STRING_RETIP "__probe_ret_ip"
#define FIELD_STRING_FUNC "__probe_func"

@@ -52,56 +53,102 @@ const char *reserved_field_names[] = {
"common_tgid",
"common_lock_depth",
FIELD_STRING_IP,
- FIELD_STRING_NARGS,
FIELD_STRING_RETIP,
FIELD_STRING_FUNC,
};

-struct fetch_func {
- unsigned long (*func)(struct pt_regs *, void *);
+/* Printing function type */
+typedef int (*print_type_func_t)(struct trace_seq *, const char *, 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)\
+{ \
+ return trace_seq_printf(s, " %s=" fmt, name, (cast)*(type *)data);\
+} \
+static const char PRINT_TYPE_FMT_NAME(type)[] = fmt;
+
+DEFINE_BASIC_PRINT_TYPE_FUNC(u8, "%x", unsigned int)
+DEFINE_BASIC_PRINT_TYPE_FUNC(u16, "%x", unsigned int)
+DEFINE_BASIC_PRINT_TYPE_FUNC(u32, "%lx", unsigned long)
+DEFINE_BASIC_PRINT_TYPE_FUNC(u64, "%llx", unsigned long long)
+DEFINE_BASIC_PRINT_TYPE_FUNC(s8, "%d", int)
+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)
+
+/* Data fetch function type */
+typedef void (*fetch_func_t)(struct pt_regs *, void *, void *);
+
+struct fetch_param {
+ fetch_func_t fn;
void *data;
};

-static __kprobes unsigned long call_fetch(struct fetch_func *f,
- struct pt_regs *regs)
+static __kprobes void call_fetch(struct fetch_param *fprm,
+ struct pt_regs *regs, void *dest)
{
- return f->func(regs, f->data);
+ return fprm->fn(regs, fprm->data, dest);
}

-/* fetch handlers */
-static __kprobes unsigned long fetch_register(struct pt_regs *regs,
- void *offset)
-{
- return regs_get_register(regs, (unsigned int)((unsigned long)offset));
+#define FETCH_FUNC_NAME(kind, type) fetch_##kind##_##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))
+
+/* 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) \
+{ \
+ *(type *)dest = (type)regs_get_register(regs, \
+ (unsigned int)((unsigned long)offset)); \
}
-
-static __kprobes unsigned long fetch_stack(struct pt_regs *regs,
- void *num)
-{
- return regs_get_kernel_stack_nth(regs,
- (unsigned int)((unsigned long)num));
+DEFINE_BASIC_FETCH_FUNCS(reg)
+
+#define DEFINE_FETCH_stack(type) \
+static __kprobes 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)); \
}
+DEFINE_BASIC_FETCH_FUNCS(stack)

-static __kprobes unsigned long fetch_memory(struct pt_regs *regs, void *addr)
-{
- unsigned long retval;
-
- if (probe_kernel_address(addr, retval))
- return 0;
- return retval;
+#define DEFINE_FETCH_retval(type) \
+static __kprobes void FETCH_FUNC_NAME(retval, type)(struct pt_regs *regs,\
+ void *dummy, void *dest) \
+{ \
+ *(type *)dest = (type)regs_return_value(regs); \
}
-
-static __kprobes unsigned long fetch_retvalue(struct pt_regs *regs,
- void *dummy)
-{
- return regs_return_value(regs);
-}
-
-static __kprobes unsigned long fetch_stack_address(struct pt_regs *regs,
- void *dummy)
-{
- return kernel_stack_pointer(regs);
+DEFINE_BASIC_FETCH_FUNCS(retval)
+
+#define DEFINE_FETCH_memory(type) \
+static __kprobes 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; \
}
+DEFINE_BASIC_FETCH_FUNCS(memory)

/* Memory fetching by symbol */
struct symbol_cache {
@@ -145,51 +192,126 @@ static struct symbol_cache *alloc_symbol_cache(const char *sym, long offset)
return sc;
}

-static __kprobes unsigned long fetch_symbol(struct pt_regs *regs, void *data)
-{
- struct symbol_cache *sc = data;
-
- if (sc->addr)
- return fetch_memory(regs, (void *)sc->addr);
- else
- return 0;
+#define DEFINE_FETCH_symbol(type) \
+static __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)

-/* Special indirect memory access interface */
-struct indirect_fetch_data {
- struct fetch_func orig;
+/* Dereference memory access function */
+struct deref_fetch_param {
+ struct fetch_param orig;
long offset;
};

-static __kprobes unsigned long fetch_indirect(struct pt_regs *regs, void *data)
-{
- struct indirect_fetch_data *ind = data;
- unsigned long addr;
-
- addr = call_fetch(&ind->orig, regs);
- if (addr) {
- addr += ind->offset;
- return fetch_memory(regs, (void *)addr);
- } else
- return 0;
+#define DEFINE_FETCH_deref(type) \
+static __kprobes void FETCH_FUNC_NAME(deref, type)(struct pt_regs *regs,\
+ void *data, void *dest) \
+{ \
+ struct deref_fetch_param *dprm = data; \
+ unsigned long addr; \
+ call_fetch(&dprm->orig, regs, &addr); \
+ if (addr) { \
+ addr += dprm->offset; \
+ fetch_memory_##type(regs, (void *)addr, dest); \
+ } else \
+ *(type *)dest = 0; \
}
+DEFINE_BASIC_FETCH_FUNCS(deref)

-static __kprobes void free_indirect_fetch_data(struct indirect_fetch_data *data)
+static __kprobes void free_deref_fetch_param(struct deref_fetch_param *data)
{
- if (data->orig.func == fetch_indirect)
- free_indirect_fetch_data(data->orig.data);
- else if (data->orig.func == fetch_symbol)
+ if (CHECK_BASIC_FETCH_FUNCS(deref, data->orig.fn))
+ free_deref_fetch_param(data->orig.data);
+ else if (CHECK_BASIC_FETCH_FUNCS(symbol, data->orig.fn))
free_symbol_cache(data->orig.data);
kfree(data);
}

+/* Default (unsigned long) fetch type */
+#define __DEFAULT_FETCH_TYPE(t) u##t
+#define _DEFAULT_FETCH_TYPE(t) __DEFAULT_FETCH_TYPE(t)
+#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 type information table */
+static const struct fetch_type {
+ const char *name; /* Name of type */
+ size_t size; /* Byte size of type */
+ int is_signed; /* Signed flag */
+ print_type_func_t print; /* Print functions */
+ const char *fmt; /* Fromat string */
+ /* 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_type_table[] = {
+ ASSIGN_FETCH_TYPE(u8, u8, 0),
+ ASSIGN_FETCH_TYPE(u16, u16, 0),
+ ASSIGN_FETCH_TYPE(u32, u32, 0),
+ ASSIGN_FETCH_TYPE(u64, u64, 0),
+ ASSIGN_FETCH_TYPE(s8, u8, 1),
+ ASSIGN_FETCH_TYPE(s16, u16, 1),
+ ASSIGN_FETCH_TYPE(s32, u32, 1),
+ ASSIGN_FETCH_TYPE(s64, u64, 1),
+};
+
+static const struct fetch_type *find_fetch_type(const char *type)
+{
+ int i;
+
+ if (!type)
+ type = DEFAULT_FETCH_TYPE_STR;
+
+ for (i = 0; i < ARRAY_SIZE(fetch_type_table); i++)
+ if (strcmp(type, fetch_type_table[i].name) == 0)
+ return &fetch_type_table[i];
+ return NULL;
+}
+
+/* Special function : only accept unsigned long */
+static __kprobes void fetch_stack_address(struct pt_regs *regs,
+ void *dummy, void *dest)
+{
+ *(unsigned long *)dest = kernel_stack_pointer(regs);
+}
+
/**
* Kprobe event core functions
*/

struct probe_arg {
- struct fetch_func fetch;
- const char *name;
+ struct fetch_param fetch;
+ unsigned int offset; /* Offset from argument entry */
+ const char *name; /* Name of this argument */
+ const char *comm; /* Command of this argument */
+ const struct fetch_type *type; /* Type of this argument */
};

/* Flags for trace_probe */
@@ -204,6 +326,7 @@ struct trace_probe {
const char *symbol; /* symbol name */
struct ftrace_event_call call;
struct trace_event event;
+ ssize_t size; /* trace entry size */
unsigned int nr_args;
struct probe_arg args[];
};
@@ -212,6 +335,7 @@ struct trace_probe {
(offsetof(struct trace_probe, args) + \
(sizeof(struct probe_arg) * (n)))

+
static __kprobes int probe_is_return(struct trace_probe *tp)
{
return tp->rp.handler != NULL;
@@ -222,49 +346,6 @@ static __kprobes const char *probe_symbol(struct trace_probe *tp)
return tp->symbol ? tp->symbol : "unknown";
}

-static int probe_arg_string(char *buf, size_t n, struct fetch_func *ff)
-{
- int ret = -EINVAL;
-
- if (ff->func == fetch_register) {
- const char *name;
- name = regs_query_register_name((unsigned int)((long)ff->data));
- ret = snprintf(buf, n, "%%%s", name);
- } else if (ff->func == fetch_stack)
- ret = snprintf(buf, n, "$stack%lu", (unsigned long)ff->data);
- else if (ff->func == fetch_memory)
- ret = snprintf(buf, n, "@0x%p", ff->data);
- else if (ff->func == fetch_symbol) {
- struct symbol_cache *sc = ff->data;
- if (sc->offset)
- ret = snprintf(buf, n, "@%s%+ld", sc->symbol,
- sc->offset);
- else
- ret = snprintf(buf, n, "@%s", sc->symbol);
- } else if (ff->func == fetch_retvalue)
- ret = snprintf(buf, n, "$retval");
- else if (ff->func == fetch_stack_address)
- ret = snprintf(buf, n, "$stack");
- else if (ff->func == fetch_indirect) {
- struct indirect_fetch_data *id = ff->data;
- size_t l = 0;
- ret = snprintf(buf, n, "%+ld(", id->offset);
- if (ret >= n)
- goto end;
- l += ret;
- ret = probe_arg_string(buf + l, n - l, &id->orig);
- if (ret < 0)
- goto end;
- l += ret;
- ret = snprintf(buf + l, n - l, ")");
- ret += l;
- }
-end:
- if (ret >= n)
- return -ENOSPC;
- return ret;
-}
-
static int register_probe_event(struct trace_probe *tp);
static void unregister_probe_event(struct trace_probe *tp);

@@ -347,11 +428,12 @@ error:

static void free_probe_arg(struct probe_arg *arg)
{
- if (arg->fetch.func == fetch_symbol)
+ if (CHECK_BASIC_FETCH_FUNCS(deref, arg->fetch.fn))
+ free_deref_fetch_param(arg->fetch.data);
+ else if (CHECK_BASIC_FETCH_FUNCS(symbol, arg->fetch.fn))
free_symbol_cache(arg->fetch.data);
- else if (arg->fetch.func == fetch_indirect)
- free_indirect_fetch_data(arg->fetch.data);
kfree(arg->name);
+ kfree(arg->comm);
}

static void free_trace_probe(struct trace_probe *tp)
@@ -457,28 +539,30 @@ static int split_symbol_offset(char *symbol, unsigned long *offset)
#define PARAM_MAX_ARGS 16
#define PARAM_MAX_STACK (THREAD_SIZE / sizeof(unsigned long))

-static int parse_probe_vars(char *arg, struct fetch_func *ff, int is_return)
+static int parse_probe_vars(char *arg, const struct fetch_type *t,
+ struct fetch_param *f, int is_return)
{
int ret = 0;
unsigned long param;

if (strcmp(arg, "retval") == 0) {
- if (is_return) {
- ff->func = fetch_retvalue;
- ff->data = NULL;
- } else
+ if (is_return)
+ f->fn = t->retval;
+ else
ret = -EINVAL;
} else if (strncmp(arg, "stack", 5) == 0) {
if (arg[5] == '\0') {
- ff->func = fetch_stack_address;
- ff->data = NULL;
+ if (strcmp(t->name, DEFAULT_FETCH_TYPE_STR) == 0)
+ f->fn = fetch_stack_address;
+ else
+ ret = -EINVAL;
} else if (isdigit(arg[5])) {
ret = strict_strtoul(arg + 5, 10, &param);
if (ret || param > PARAM_MAX_STACK)
ret = -EINVAL;
else {
- ff->func = fetch_stack;
- ff->data = (void *)param;
+ f->fn = t->stack;
+ f->data = (void *)param;
}
} else
ret = -EINVAL;
@@ -488,7 +572,8 @@ static int parse_probe_vars(char *arg, struct fetch_func *ff, int is_return)
}

/* Recursive argument parser */
-static int __parse_probe_arg(char *arg, struct fetch_func *ff, int is_return)
+static int __parse_probe_arg(char *arg, const struct fetch_type *t,
+ struct fetch_param *f, int is_return)
{
int ret = 0;
unsigned long param;
@@ -497,13 +582,13 @@ static int __parse_probe_arg(char *arg, struct fetch_func *ff, int is_return)

switch (arg[0]) {
case '$':
- ret = parse_probe_vars(arg + 1, ff, is_return);
+ ret = parse_probe_vars(arg + 1, t, f, is_return);
break;
case '%': /* named register */
ret = regs_query_register_offset(arg + 1);
if (ret >= 0) {
- ff->func = fetch_register;
- ff->data = (void *)(unsigned long)ret;
+ f->fn = t->reg;
+ f->data = (void *)(unsigned long)ret;
ret = 0;
}
break;
@@ -512,26 +597,22 @@ static int __parse_probe_arg(char *arg, struct fetch_func *ff, int is_return)
ret = strict_strtoul(arg + 1, 0, &param);
if (ret)
break;
- ff->func = fetch_memory;
- ff->data = (void *)param;
+ f->fn = t->memory;
+ f->data = (void *)param;
} else {
ret = split_symbol_offset(arg + 1, &offset);
if (ret)
break;
- ff->data = alloc_symbol_cache(arg + 1, offset);
- if (ff->data)
- ff->func = fetch_symbol;
- else
- ret = -EINVAL;
+ f->data = alloc_symbol_cache(arg + 1, offset);
+ if (f->data)
+ f->fn = t->symbol;
}
break;
- case '+': /* indirect memory */
+ case '+': /* deref memory */
case '-':
tmp = strchr(arg, '(');
- if (!tmp) {
- ret = -EINVAL;
+ if (!tmp)
break;
- }
*tmp = '\0';
ret = strict_strtol(arg + 1, 0, &offset);
if (ret)
@@ -541,38 +622,58 @@ static int __parse_probe_arg(char *arg, struct fetch_func *ff, int is_return)
arg = tmp + 1;
tmp = strrchr(arg, ')');
if (tmp) {
- struct indirect_fetch_data *id;
+ struct deref_fetch_param *dprm;
+ const struct fetch_type *t2 = find_fetch_type(NULL);
*tmp = '\0';
- id = kzalloc(sizeof(struct indirect_fetch_data),
- GFP_KERNEL);
- if (!id)
+ dprm = kzalloc(sizeof(struct deref_fetch_param),
+ GFP_KERNEL);
+ if (!dprm)
return -ENOMEM;
- id->offset = offset;
- ret = __parse_probe_arg(arg, &id->orig, is_return);
+ dprm->offset = offset;
+ ret = __parse_probe_arg(arg, t2, &dprm->orig,
+ is_return);
if (ret)
- kfree(id);
+ kfree(dprm);
else {
- ff->func = fetch_indirect;
- ff->data = (void *)id;
+ f->fn = t->deref;
+ f->data = (void *)dprm;
}
- } else
- ret = -EINVAL;
+ }
break;
- default:
- /* TODO: support custom handler */
- ret = -EINVAL;
}
+ if (!ret && !f->fn)
+ ret = -EINVAL;
return ret;
}

/* String length checking wrapper */
-static int parse_probe_arg(char *arg, struct fetch_func *ff, int is_return)
+static int parse_probe_arg(char *arg, struct trace_probe *tp,
+ struct probe_arg *parg, int is_return)
{
+ const char *t;
+
if (strlen(arg) > MAX_ARGSTR_LEN) {
pr_info("Argument is too long.: %s\n", arg);
return -ENOSPC;
}
- return __parse_probe_arg(arg, ff, is_return);
+ parg->comm = kstrdup(arg, GFP_KERNEL);
+ if (!parg->comm) {
+ pr_info("Failed to allocate memory for command '%s'.\n", arg);
+ return -ENOMEM;
+ }
+ t = strchr(parg->comm, ':');
+ if (t) {
+ arg[t - parg->comm] = '\0';
+ t++;
+ }
+ parg->type = find_fetch_type(t);
+ if (!parg->type) {
+ pr_info("Unsupported type: %s\n", t);
+ return -EINVAL;
+ }
+ parg->offset = tp->size;
+ tp->size += parg->type->size;
+ return __parse_probe_arg(arg, parg->type, &parg->fetch, is_return);
}

/* Return 1 if name is reserved or already used by another argument */
@@ -602,15 +703,18 @@ static int create_trace_probe(int argc, char **argv)
* @ADDR : fetch memory at ADDR (ADDR should be in kernel)
* @SYM[+|-offs] : fetch memory at SYM +|- offs (SYM is a data symbol)
* %REG : fetch register REG
- * Indirect memory fetch:
+ * Dereferencing memory fetch:
* +|-offs(ARG) : fetch memory at ARG +|- offs address.
* Alias name of args:
* NAME=FETCHARG : set NAME as alias of FETCHARG.
+ * Type of args:
+ * FETCHARG:TYPE : use TYPE instead of unsigned long.
*/
struct trace_probe *tp;
int i, ret = 0;
int is_return = 0, is_delete = 0;
- char *symbol = NULL, *event = NULL, *arg = NULL, *group = NULL;
+ char *symbol = NULL, *event = NULL, *group = NULL;
+ char *arg, *tmp;
unsigned long offset = 0;
void *addr = NULL;
char buf[MAX_EVENT_NAME_LEN];
@@ -723,13 +827,6 @@ static int create_trace_probe(int argc, char **argv)
else
arg = argv[i];

- if (conflict_field_name(argv[i], tp->args, i)) {
- pr_info("Argument%d name '%s' conflicts with "
- "another field.\n", i, argv[i]);
- ret = -EINVAL;
- goto error;
- }
-
tp->args[i].name = kstrdup(argv[i], GFP_KERNEL);
if (!tp->args[i].name) {
pr_info("Failed to allocate argument%d name '%s'.\n",
@@ -737,9 +834,19 @@ static int create_trace_probe(int argc, char **argv)
ret = -ENOMEM;
goto error;
}
+ tmp = strchr(tp->args[i].name, ':');
+ if (tmp)
+ *tmp = '_'; /* convert : to _ */
+
+ if (conflict_field_name(tp->args[i].name, tp->args, i)) {
+ pr_info("Argument%d name '%s' conflicts with "
+ "another field.\n", i, argv[i]);
+ ret = -EINVAL;
+ goto error;
+ }

/* Parse fetch argument */
- ret = parse_probe_arg(arg, &tp->args[i].fetch, is_return);
+ ret = parse_probe_arg(arg, tp, &tp->args[i], is_return);
if (ret) {
pr_info("Parse error at argument%d. (%d)\n", i, ret);
kfree(tp->args[i].name);
@@ -794,8 +901,7 @@ static void probes_seq_stop(struct seq_file *m, void *v)
static int probes_seq_show(struct seq_file *m, void *v)
{
struct trace_probe *tp = v;
- int i, ret;
- char buf[MAX_ARGSTR_LEN + 1];
+ int i;

seq_printf(m, "%c", probe_is_return(tp) ? 'r' : 'p');
seq_printf(m, ":%s/%s", tp->call.system, tp->call.name);
@@ -807,15 +913,10 @@ static int probes_seq_show(struct seq_file *m, void *v)
else
seq_printf(m, " %s", probe_symbol(tp));

- for (i = 0; i < tp->nr_args; i++) {
- ret = probe_arg_string(buf, MAX_ARGSTR_LEN, &tp->args[i].fetch);
- if (ret < 0) {
- pr_warning("Argument%d decoding error(%d).\n", i, ret);
- return ret;
- }
- seq_printf(m, " %s=%s", tp->args[i].name, buf);
- }
+ for (i = 0; i < tp->nr_args; i++)
+ seq_printf(m, " %s=%s", tp->args[i].name, tp->args[i].comm);
seq_printf(m, "\n");
+
return 0;
}

@@ -945,9 +1046,10 @@ static const struct file_operations kprobe_profile_ops = {
static __kprobes void kprobe_trace_func(struct kprobe *kp, struct pt_regs *regs)
{
struct trace_probe *tp = container_of(kp, struct trace_probe, rp.kp);
- struct kprobe_trace_entry *entry;
+ struct kprobe_trace_entry_head *entry;
struct ring_buffer_event *event;
struct ring_buffer *buffer;
+ u8 *data;
int size, i, pc;
unsigned long irq_flags;
struct ftrace_event_call *call = &tp->call;
@@ -957,7 +1059,7 @@ static __kprobes void kprobe_trace_func(struct kprobe *kp, struct pt_regs *regs)
local_save_flags(irq_flags);
pc = preempt_count();

- size = SIZEOF_KPROBE_TRACE_ENTRY(tp->nr_args);
+ size = sizeof(*entry) + tp->size;

event = trace_current_buffer_lock_reserve(&buffer, call->id, size,
irq_flags, pc);
@@ -965,10 +1067,10 @@ static __kprobes void kprobe_trace_func(struct kprobe *kp, struct pt_regs *regs)
return;

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

if (!filter_current_check_discard(buffer, call, entry, event))
trace_nowake_buffer_unlock_commit(buffer, event, irq_flags, pc);
@@ -979,9 +1081,10 @@ static __kprobes void kretprobe_trace_func(struct kretprobe_instance *ri,
struct pt_regs *regs)
{
struct trace_probe *tp = container_of(ri->rp, struct trace_probe, rp);
- struct kretprobe_trace_entry *entry;
+ struct kretprobe_trace_entry_head *entry;
struct ring_buffer_event *event;
struct ring_buffer *buffer;
+ u8 *data;
int size, i, pc;
unsigned long irq_flags;
struct ftrace_event_call *call = &tp->call;
@@ -989,7 +1092,7 @@ static __kprobes void kretprobe_trace_func(struct kretprobe_instance *ri,
local_save_flags(irq_flags);
pc = preempt_count();

- size = SIZEOF_KRETPROBE_TRACE_ENTRY(tp->nr_args);
+ size = sizeof(*entry) + tp->size;

event = trace_current_buffer_lock_reserve(&buffer, call->id, size,
irq_flags, pc);
@@ -997,11 +1100,11 @@ static __kprobes void kretprobe_trace_func(struct kretprobe_instance *ri,
return;

entry = ring_buffer_event_data(event);
- entry->nargs = tp->nr_args;
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++)
- entry->args[i] = call_fetch(&tp->args[i].fetch, regs);
+ call_fetch(&tp->args[i].fetch, regs, data + tp->args[i].offset);

if (!filter_current_check_discard(buffer, call, entry, event))
trace_nowake_buffer_unlock_commit(buffer, event, irq_flags, pc);
@@ -1011,13 +1114,14 @@ static __kprobes void kretprobe_trace_func(struct kretprobe_instance *ri,
enum print_line_t
print_kprobe_event(struct trace_iterator *iter, int flags)
{
- struct kprobe_trace_entry *field;
+ struct kprobe_trace_entry_head *field;
struct trace_seq *s = &iter->seq;
struct trace_event *event;
struct trace_probe *tp;
+ u8 *data;
int i;

- field = (struct kprobe_trace_entry *)iter->ent;
+ field = (struct kprobe_trace_entry_head *)iter->ent;
event = ftrace_find_event(field->ent.type);
tp = container_of(event, struct trace_probe, event);

@@ -1030,9 +1134,10 @@ print_kprobe_event(struct trace_iterator *iter, int flags)
if (!trace_seq_puts(s, ")"))
goto partial;

- for (i = 0; i < field->nargs; i++)
- if (!trace_seq_printf(s, " %s=%lx",
- tp->args[i].name, field->args[i]))
+ 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))
goto partial;

if (!trace_seq_puts(s, "\n"))
@@ -1046,13 +1151,14 @@ partial:
enum print_line_t
print_kretprobe_event(struct trace_iterator *iter, int flags)
{
- struct kretprobe_trace_entry *field;
+ struct kretprobe_trace_entry_head *field;
struct trace_seq *s = &iter->seq;
struct trace_event *event;
struct trace_probe *tp;
+ u8 *data;
int i;

- field = (struct kretprobe_trace_entry *)iter->ent;
+ field = (struct kretprobe_trace_entry_head *)iter->ent;
event = ftrace_find_event(field->ent.type);
tp = container_of(event, struct trace_probe, event);

@@ -1071,9 +1177,10 @@ print_kretprobe_event(struct trace_iterator *iter, int flags)
if (!trace_seq_puts(s, ")"))
goto partial;

- for (i = 0; i < field->nargs; i++)
- if (!trace_seq_printf(s, " %s=%lx",
- tp->args[i].name, field->args[i]))
+ 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))
goto partial;

if (!trace_seq_puts(s, "\n"))
@@ -1129,29 +1236,43 @@ static int probe_event_raw_init(struct ftrace_event_call *event_call)
static int kprobe_event_define_fields(struct ftrace_event_call *event_call)
{
int ret, i;
- struct kprobe_trace_entry field;
+ struct kprobe_trace_entry_head field;
struct trace_probe *tp = (struct trace_probe *)event_call->data;

DEFINE_FIELD(unsigned long, ip, FIELD_STRING_IP, 0);
- DEFINE_FIELD(int, nargs, FIELD_STRING_NARGS, 1);
/* Set argument names as fields */
- for (i = 0; i < tp->nr_args; i++)
- DEFINE_FIELD(unsigned long, args[i], tp->args[i].name, 0);
+ for (i = 0; i < tp->nr_args; i++) {
+ ret = trace_define_field(event_call, tp->args[i].type->name,
+ tp->args[i].name,
+ sizeof(field) + tp->args[i].offset,
+ tp->args[i].type->size,
+ tp->args[i].type->is_signed,
+ FILTER_OTHER);
+ if (ret)
+ return ret;
+ }
return 0;
}

static int kretprobe_event_define_fields(struct ftrace_event_call *event_call)
{
int ret, i;
- struct kretprobe_trace_entry field;
+ struct kretprobe_trace_entry_head field;
struct trace_probe *tp = (struct trace_probe *)event_call->data;

DEFINE_FIELD(unsigned long, func, FIELD_STRING_FUNC, 0);
DEFINE_FIELD(unsigned long, ret_ip, FIELD_STRING_RETIP, 0);
- DEFINE_FIELD(int, nargs, FIELD_STRING_NARGS, 1);
/* Set argument names as fields */
- for (i = 0; i < tp->nr_args; i++)
- DEFINE_FIELD(unsigned long, args[i], tp->args[i].name, 0);
+ for (i = 0; i < tp->nr_args; i++) {
+ ret = trace_define_field(event_call, tp->args[i].type->name,
+ tp->args[i].name,
+ sizeof(field) + tp->args[i].offset,
+ tp->args[i].type->size,
+ tp->args[i].type->is_signed,
+ FILTER_OTHER);
+ if (ret)
+ return ret;
+ }
return 0;
}

@@ -1176,8 +1297,8 @@ static int __set_print_fmt(struct trace_probe *tp, char *buf, int len)
pos += snprintf(buf + pos, LEN_OR_ZERO, "\"%s", fmt);

for (i = 0; i < tp->nr_args; i++) {
- pos += snprintf(buf + pos, LEN_OR_ZERO, " %s=%%lx",
- tp->args[i].name);
+ pos += snprintf(buf + pos, LEN_OR_ZERO, " %s=%s",
+ tp->args[i].name, tp->args[i].type->fmt);
}

pos += snprintf(buf + pos, LEN_OR_ZERO, "\", %s", arg);
@@ -1219,12 +1340,13 @@ 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 *entry;
+ struct kprobe_trace_entry_head *entry;
+ u8 *data;
int size, __size, i;
unsigned long irq_flags;
int rctx;

- __size = SIZEOF_KPROBE_TRACE_ENTRY(tp->nr_args);
+ __size = sizeof(*entry) + tp->size;
size = ALIGN(__size + sizeof(u32), sizeof(u64));
size -= sizeof(u32);
if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE,
@@ -1235,10 +1357,10 @@ static __kprobes void kprobe_perf_func(struct kprobe *kp,
if (!entry)
return;

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

perf_trace_buf_submit(entry, size, rctx, entry->ip, 1, irq_flags, regs);
}
@@ -1249,12 +1371,13 @@ 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 *entry;
+ struct kretprobe_trace_entry_head *entry;
+ u8 *data;
int size, __size, i;
unsigned long irq_flags;
int rctx;

- __size = SIZEOF_KRETPROBE_TRACE_ENTRY(tp->nr_args);
+ __size = sizeof(*entry) + tp->size;
size = ALIGN(__size + sizeof(u32), sizeof(u64));
size -= sizeof(u32);
if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE,
@@ -1265,11 +1388,11 @@ static __kprobes void kretprobe_perf_func(struct kretprobe_instance *ri,
if (!entry)
return;

- entry->nargs = tp->nr_args;
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++)
- entry->args[i] = call_fetch(&tp->args[i].fetch, regs);
+ call_fetch(&tp->args[i].fetch, regs, data + tp->args[i].offset);

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


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