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Subject[PATCH 08/17] tracing/probes: Split [ku]probes_fetch_type_table
Date
From: Namhyung Kim <namhyung.kim@lge.com>

Use separate fetch_type_table for kprobes and uprobes. It currently
shares all fetch methods but some of them will be implemented
differently later.

This is not to break build if [ku]probes is configured alone (like
!CONFIG_KPROBE_EVENT and CONFIG_UPROBE_EVENT). So I added '__weak'
to the table declaration so that it can be safely omitted when it
configured out.

Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: zhangwei(Jovi) <jovi.zhangwei@huawei.com>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
kernel/trace/trace_kprobe.c | 20 ++++++++++++++
kernel/trace/trace_probe.c | 65 ++++++++++++++++++---------------------------
kernel/trace/trace_probe.h | 53 ++++++++++++++++++++++++++++++++++++
kernel/trace/trace_uprobe.c | 20 ++++++++++++++
4 files changed, 119 insertions(+), 39 deletions(-)

diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index 62d6c961bbce..23c6c3feff82 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -88,6 +88,26 @@ static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs);
static int kretprobe_dispatcher(struct kretprobe_instance *ri,
struct pt_regs *regs);

+/* Fetch type information table */
+const struct fetch_type kprobes_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),
+ 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),
+
+ ASSIGN_FETCH_TYPE_END
+};
+
/*
* Allocate new trace_probe and initialize it (including kprobes).
*/
diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c
index c26bc9eaa2ac..541036ec7392 100644
--- a/kernel/trace/trace_probe.c
+++ b/kernel/trace/trace_probe.c
@@ -54,10 +54,6 @@ DEFINE_BASIC_PRINT_TYPE_FUNC(s16, "%d")
DEFINE_BASIC_PRINT_TYPE_FUNC(s32, "%d")
DEFINE_BASIC_PRINT_TYPE_FUNC(s64, "%Ld")

-/* For defining macros, define string/string_size types */
-typedef u32 string;
-typedef u32 string_size;
-
/* Print type function for string type */
__kprobes int PRINT_TYPE_FUNC_NAME(string)(struct trace_seq *s,
const char *name,
@@ -74,7 +70,6 @@ __kprobes int PRINT_TYPE_FUNC_NAME(string)(struct trace_seq *s,

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

-#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.
@@ -359,25 +354,8 @@ free_bitfield_fetch_param(struct bitfield_fetch_param *data)
kfree(data);
}

-/* Fetch type information table */
-static const struct fetch_type 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),
- 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)
+static const struct fetch_type *find_fetch_type(const char *type,
+ const struct fetch_type *ftbl)
{
int i;

@@ -398,21 +376,22 @@ static const struct fetch_type *find_fetch_type(const char *type)

switch (bs) {
case 8:
- return find_fetch_type("u8");
+ return find_fetch_type("u8", ftbl);
case 16:
- return find_fetch_type("u16");
+ return find_fetch_type("u16", ftbl);
case 32:
- return find_fetch_type("u32");
+ return find_fetch_type("u32", ftbl);
case 64:
- return find_fetch_type("u64");
+ return find_fetch_type("u64", ftbl);
default:
goto fail;
}
}

- for (i = 0; i < ARRAY_SIZE(fetch_type_table); i++)
- if (strcmp(type, fetch_type_table[i].name) == 0)
- return &fetch_type_table[i];
+ for (i = 0; ftbl[i].name; i++) {
+ if (strcmp(type, ftbl[i].name) == 0)
+ return &ftbl[i];
+ }

fail:
return NULL;
@@ -426,16 +405,17 @@ static __kprobes void fetch_stack_address(struct pt_regs *regs,
}

static fetch_func_t get_fetch_size_function(const struct fetch_type *type,
- fetch_func_t orig_fn)
+ fetch_func_t orig_fn,
+ const struct fetch_type *ftbl)
{
int i;

- if (type != &fetch_type_table[FETCH_TYPE_STRING])
+ if (type != &ftbl[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];
+ return ftbl[FETCH_TYPE_STRSIZE].fetch[i];

WARN_ON(1); /* This should not happen */

@@ -504,12 +484,14 @@ static int parse_probe_vars(char *arg, const struct fetch_type *t,
static int parse_probe_arg(char *arg, const struct fetch_type *t,
struct fetch_param *f, bool is_return, bool is_kprobe)
{
+ const struct fetch_type *ftbl;
unsigned long param;
long offset;
char *tmp;
- int ret;
+ int ret = 0;

- ret = 0;
+ ftbl = is_kprobe ? kprobes_fetch_type_table : uprobes_fetch_type_table;
+ BUG_ON(ftbl == NULL);

/* Until uprobe_events supports only reg arguments */
if (!is_kprobe && arg[0] != '%')
@@ -568,7 +550,7 @@ static int parse_probe_arg(char *arg, const struct fetch_type *t,
struct deref_fetch_param *dprm;
const struct fetch_type *t2;

- t2 = find_fetch_type(NULL);
+ t2 = find_fetch_type(NULL, ftbl);
*tmp = '\0';
dprm = kzalloc(sizeof(struct deref_fetch_param), GFP_KERNEL);

@@ -637,9 +619,13 @@ static int __parse_bitfield_probe_arg(const char *bf,
int traceprobe_parse_probe_arg(char *arg, ssize_t *size,
struct probe_arg *parg, bool is_return, bool is_kprobe)
{
+ const struct fetch_type *ftbl;
const char *t;
int ret;

+ ftbl = is_kprobe ? kprobes_fetch_type_table : uprobes_fetch_type_table;
+ BUG_ON(ftbl == NULL);
+
if (strlen(arg) > MAX_ARGSTR_LEN) {
pr_info("Argument is too long.: %s\n", arg);
return -ENOSPC;
@@ -654,7 +640,7 @@ int traceprobe_parse_probe_arg(char *arg, ssize_t *size,
arg[t - parg->comm] = '\0';
t++;
}
- parg->type = find_fetch_type(t);
+ parg->type = find_fetch_type(t, ftbl);
if (!parg->type) {
pr_info("Unsupported type: %s\n", t);
return -EINVAL;
@@ -668,7 +654,8 @@ int traceprobe_parse_probe_arg(char *arg, ssize_t *size,

if (ret >= 0) {
parg->fetch_size.fn = get_fetch_size_function(parg->type,
- parg->fetch.fn);
+ parg->fetch.fn,
+ ftbl);
parg->fetch_size.data = parg->fetch.data;
}

diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h
index bd621c08b6c6..5b77798d1130 100644
--- a/kernel/trace/trace_probe.h
+++ b/kernel/trace/trace_probe.h
@@ -126,6 +126,10 @@ struct fetch_param {
void *data;
};

+/* For defining macros, define string/string_size types */
+typedef u32 string;
+typedef u32 string_size;
+
#define PRINT_TYPE_FUNC_NAME(type) print_type_##type
#define PRINT_TYPE_FMT_NAME(type) print_type_format_##type

@@ -146,6 +150,47 @@ DECLARE_BASIC_PRINT_TYPE_FUNC(s32);
DECLARE_BASIC_PRINT_TYPE_FUNC(s64);
DECLARE_BASIC_PRINT_TYPE_FUNC(string);

+#define FETCH_FUNC_NAME(method, type) fetch_##method##_##type
+
+/* Declare macro for basic types */
+#define DECLARE_FETCH_FUNC(method, type) \
+extern void FETCH_FUNC_NAME(method, type)(struct pt_regs *regs, \
+ void *data, void *dest)
+
+#define DECLARE_BASIC_FETCH_FUNCS(method) \
+DECLARE_FETCH_FUNC(method, u8); \
+DECLARE_FETCH_FUNC(method, u16); \
+DECLARE_FETCH_FUNC(method, u32); \
+DECLARE_FETCH_FUNC(method, u64)
+
+DECLARE_BASIC_FETCH_FUNCS(reg);
+#define fetch_reg_string NULL
+#define fetch_reg_string_size NULL
+
+DECLARE_BASIC_FETCH_FUNCS(stack);
+#define fetch_stack_string NULL
+#define fetch_stack_string_size NULL
+
+DECLARE_BASIC_FETCH_FUNCS(retval);
+#define fetch_retval_string NULL
+#define fetch_retval_string_size NULL
+
+DECLARE_BASIC_FETCH_FUNCS(memory);
+DECLARE_FETCH_FUNC(memory, string);
+DECLARE_FETCH_FUNC(memory, string_size);
+
+DECLARE_BASIC_FETCH_FUNCS(symbol);
+DECLARE_FETCH_FUNC(symbol, string);
+DECLARE_FETCH_FUNC(symbol, string_size);
+
+DECLARE_BASIC_FETCH_FUNCS(deref);
+DECLARE_FETCH_FUNC(deref, string);
+DECLARE_FETCH_FUNC(deref, string_size);
+
+DECLARE_BASIC_FETCH_FUNCS(bitfield);
+#define fetch_bitfield_string NULL
+#define fetch_bitfield_string_size NULL
+
/* Default (unsigned long) fetch type */
#define __DEFAULT_FETCH_TYPE(t) u##t
#define _DEFAULT_FETCH_TYPE(t) __DEFAULT_FETCH_TYPE(t)
@@ -176,9 +221,17 @@ ASSIGN_FETCH_FUNC(bitfield, ftype), \
#define ASSIGN_FETCH_TYPE(ptype, ftype, sign) \
__ASSIGN_FETCH_TYPE(#ptype, ptype, ftype, sizeof(ftype), sign, #ptype)

+#define ASSIGN_FETCH_TYPE_END {}
+
#define FETCH_TYPE_STRING 0
#define FETCH_TYPE_STRSIZE 1

+/*
+ * Fetch type information table.
+ * It's declared as a weak symbol due to conditional compilation.
+ */
+extern __weak const struct fetch_type kprobes_fetch_type_table[];
+extern __weak const struct fetch_type uprobes_fetch_type_table[];

struct probe_arg {
struct fetch_param fetch;
diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c
index b233d9cb1216..2c60925ea073 100644
--- a/kernel/trace/trace_uprobe.c
+++ b/kernel/trace/trace_uprobe.c
@@ -74,6 +74,26 @@ static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs);
static int uretprobe_dispatcher(struct uprobe_consumer *con,
unsigned long func, struct pt_regs *regs);

+/* Fetch type information table */
+const struct fetch_type uprobes_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),
+ 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),
+
+ ASSIGN_FETCH_TYPE_END
+};
+
static inline void init_trace_uprobe_filter(struct trace_uprobe_filter *filter)
{
rwlock_init(&filter->rwlock);
--
1.7.11.7


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