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Kirill Smelkov
bcc
Commits
10436451
Commit
10436451
authored
May 04, 2016
by
Vicent Marti
Browse files
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Email Patches
Plain Diff
cc: Better memory handling for USDT probes
parent
4ea4af45
Changes
5
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Side-by-side
Showing
5 changed files
with
109 additions
and
112 deletions
+109
-112
src/cc/bcc_syms.cc
src/cc/bcc_syms.cc
+10
-7
src/cc/syms.h
src/cc/syms.h
+1
-0
src/cc/usdt.cc
src/cc/usdt.cc
+69
-80
src/cc/usdt.h
src/cc/usdt.h
+19
-15
tests/cc/test_usdt_probes.cc
tests/cc/test_usdt_probes.cc
+10
-10
No files found.
src/cc/bcc_syms.cc
View file @
10436451
...
...
@@ -24,17 +24,16 @@
#include "bcc_syms.h"
#include "syms.h"
#include "vendor/tinyformat.hpp"
ino_t
ProcStat
::
getinode_
()
{
struct
stat
s
;
return
(
!
stat
(
procfs_
.
c_str
(),
&
s
))
?
s
.
st_ino
:
-
1
;
}
ProcStat
::
ProcStat
(
int
pid
)
:
inode_
(
-
1
)
{
char
buffer
[
128
];
snprintf
(
buffer
,
sizeof
(
buffer
),
"/proc/%d/exe"
,
pid
);
procfs_
=
buffer
;
}
ProcStat
::
ProcStat
(
int
pid
)
:
procfs_
(
tfm
::
format
(
"/proc/%d/exe"
,
pid
)),
inode_
(
getinode_
())
{}
void
KSyms
::
_add_symbol
(
const
char
*
symname
,
uint64_t
addr
,
void
*
p
)
{
KSyms
*
ks
=
static_cast
<
KSyms
*>
(
p
);
...
...
@@ -84,11 +83,15 @@ bool KSyms::resolve_name(const char *_unused, const char *name,
return
true
;
}
ProcSyms
::
ProcSyms
(
int
pid
)
:
pid_
(
pid
),
procstat_
(
pid
)
{
refresh
();
}
ProcSyms
::
ProcSyms
(
int
pid
)
:
pid_
(
pid
),
procstat_
(
pid
)
{
load_modules
();
}
bool
ProcSyms
::
load_modules
()
{
return
bcc_procutils_each_module
(
pid_
,
_add_module
,
this
)
==
0
;
}
void
ProcSyms
::
refresh
()
{
modules_
.
clear
();
bcc_procutils_each_module
(
pid_
,
_add_module
,
this
);
load_modules
(
);
procstat_
.
reset
();
}
...
...
src/cc/syms.h
View file @
10436451
...
...
@@ -93,6 +93,7 @@ class ProcSyms : SymbolCache {
ProcStat
procstat_
;
static
int
_add_module
(
const
char
*
,
uint64_t
,
uint64_t
,
void
*
);
bool
load_modules
();
public:
ProcSyms
(
int
pid
);
...
...
src/cc/usdt.cc
View file @
10436451
...
...
@@ -38,11 +38,12 @@ Probe::Location::Location(uint64_t addr, const char *arg_fmt) : address_(addr) {
}
Probe
::
Probe
(
const
char
*
bin_path
,
const
char
*
provider
,
const
char
*
name
,
uint64_t
semaphore
)
uint64_t
semaphore
,
const
optional
<
int
>
&
pid
)
:
bin_path_
(
bin_path
),
provider_
(
provider
),
name_
(
name
),
semaphore_
(
semaphore
)
{}
semaphore_
(
semaphore
),
pid_
(
pid
)
{}
bool
Probe
::
in_shared_object
()
{
if
(
!
in_shared_object_
)
...
...
@@ -50,45 +51,36 @@ bool Probe::in_shared_object() {
return
in_shared_object_
.
value
();
}
bool
Probe
::
resolve_global_address
(
uint64_t
*
global
,
const
uint64_t
addr
,
optional
<
int
>
pid
)
{
bool
Probe
::
resolve_global_address
(
uint64_t
*
global
,
const
uint64_t
addr
)
{
if
(
in_shared_object
())
{
return
(
pid
&&
bcc_resolve_global_addr
(
*
pid
,
bin_path_
.
c_str
(),
addr
,
global
)
==
0
);
return
(
pid_
&&
!
bcc_resolve_global_addr
(
*
pid_
,
bin_path_
.
c_str
(),
addr
,
global
));
}
*
global
=
addr
;
return
true
;
}
bool
Probe
::
lookup_semaphore_addr
(
uint64_t
*
address
,
int
pid
)
{
auto
it
=
semaphores_
.
find
(
pid
);
if
(
it
!=
semaphores_
.
end
())
{
*
address
=
it
->
second
;
return
true
;
}
bool
Probe
::
add_to_semaphore
(
int16_t
val
)
{
assert
(
pid_
&&
attached_semaphore_
);
if
(
!
resolve_global_address
(
address
,
semaphore_
,
pid
))
return
false
;
if
(
!
attached_semaphore_
)
{
uint64_t
addr
;
if
(
!
resolve_global_address
(
&
addr
,
semaphore_
))
return
false
;
attached_semaphore_
=
addr
;
}
semaphores_
[
pid
]
=
*
address
;
return
true
;
}
off_t
address
=
static_cast
<
off_t
>
(
attached_semaphore_
.
value
());
bool
Probe
::
add_to_semaphore
(
int
pid
,
int16_t
val
)
{
uint64_t
address
;
if
(
!
lookup_semaphore_addr
(
&
address
,
pid
))
return
false
;
std
::
string
procmem
=
tfm
::
format
(
"/proc/%d/mem"
,
pid
);
std
::
string
procmem
=
tfm
::
format
(
"/proc/%d/mem"
,
pid_
.
value
());
int
memfd
=
::
open
(
procmem
.
c_str
(),
O_RDWR
);
if
(
memfd
<
0
)
return
false
;
int16_t
original
;
// TODO: should this be unsigned?
int16_t
original
;
if
(
::
lseek
(
memfd
,
static_cast
<
off_t
>
(
address
)
,
SEEK_SET
)
<
0
||
if
(
::
lseek
(
memfd
,
address
,
SEEK_SET
)
<
0
||
::
read
(
memfd
,
&
original
,
2
)
!=
2
)
{
::
close
(
memfd
);
return
false
;
...
...
@@ -96,7 +88,7 @@ bool Probe::add_to_semaphore(int pid, int16_t val) {
original
=
original
+
val
;
if
(
::
lseek
(
memfd
,
static_cast
<
off_t
>
(
address
)
,
SEEK_SET
)
<
0
||
if
(
::
lseek
(
memfd
,
address
,
SEEK_SET
)
<
0
||
::
write
(
memfd
,
&
original
,
2
)
!=
2
)
{
::
close
(
memfd
);
return
false
;
...
...
@@ -106,28 +98,33 @@ bool Probe::add_to_semaphore(int pid, int16_t val) {
return
true
;
}
bool
Probe
::
enable
(
int
pid
)
{
if
(
enabled_semaphores_
.
find
(
pid
)
!=
enabled_semaphores_
.
end
())
return
true
;
if
(
!
add_to_semaphore
(
pid
,
+
1
))
bool
Probe
::
enable
(
const
std
::
string
&
fn_name
)
{
if
(
attached_to_
)
return
false
;
enabled_semaphores_
.
emplace
(
pid
,
std
::
move
(
ProcStat
(
pid
)));
if
(
need_enable
())
{
if
(
!
pid_
)
return
false
;
if
(
!
add_to_semaphore
(
+
1
))
return
false
;
}
attached_to_
=
fn_name
;
return
true
;
}
bool
Probe
::
disable
(
int
pid
)
{
auto
it
=
enabled_semaphores_
.
find
(
pid
);
if
(
it
==
enabled_semaphores_
.
end
())
bool
Probe
::
disable
()
{
if
(
!
attached_to_
)
return
false
;
bool
result
=
true
;
if
(
!
it
->
second
.
is_stale
())
result
=
add_to_semaphore
(
pid
,
-
1
);
attached_to_
=
nullopt
;
enabled_semaphores_
.
erase
(
it
);
return
result
;
if
(
need_enable
())
{
assert
(
pid_
);
return
add_to_semaphore
(
-
1
);
}
return
true
;
}
std
::
string
Probe
::
largest_arg_type
(
size_t
arg_n
)
{
...
...
@@ -143,10 +140,12 @@ std::string Probe::largest_arg_type(size_t arg_n) {
return
largest
->
ctype
();
}
bool
Probe
::
usdt_getarg
(
std
::
ostream
&
stream
,
const
std
::
string
&
fn_name
,
const
optional
<
int
>
&
pid
)
{
bool
Probe
::
usdt_getarg
(
std
::
ostream
&
stream
)
{
const
size_t
arg_count
=
locations_
[
0
].
arguments_
.
size
();
if
(
!
attached_to_
)
return
false
;
if
(
arg_count
==
0
)
return
true
;
...
...
@@ -158,13 +157,13 @@ bool Probe::usdt_getarg(std::ostream &stream,
"static inline int _bpf_readarg_%s_%d("
"struct pt_regs *ctx, void *dest, size_t len) {
\n
"
" if (len != sizeof(%s)) return -1;
\n
"
,
fn_name
,
arg_n
+
1
,
ctype
);
attached_to_
.
value
()
,
arg_n
+
1
,
ctype
);
if
(
locations_
.
size
()
==
1
)
{
Location
&
location
=
locations_
.
front
();
stream
<<
" "
;
if
(
!
location
.
arguments_
[
arg_n
].
assign_to_local
(
stream
,
cptr
,
bin_path_
,
pid
))
bin_path_
,
pid
_
))
return
false
;
stream
<<
"
\n
return 0;
\n
}
\n
"
;
}
else
{
...
...
@@ -172,12 +171,12 @@ bool Probe::usdt_getarg(std::ostream &stream,
for
(
Location
&
location
:
locations_
)
{
uint64_t
global_address
;
if
(
!
resolve_global_address
(
&
global_address
,
location
.
address_
,
pid
))
if
(
!
resolve_global_address
(
&
global_address
,
location
.
address_
))
return
false
;
tfm
::
format
(
stream
,
" case 0x%xULL: "
,
global_address
);
if
(
!
location
.
arguments_
[
arg_n
].
assign_to_local
(
stream
,
cptr
,
bin_path_
,
pid
))
bin_path_
,
pid
_
))
return
false
;
stream
<<
" return 0;
\n
"
;
...
...
@@ -205,22 +204,16 @@ int Context::_each_module(const char *modpath, uint64_t, uint64_t, void *p) {
}
void
Context
::
add_probe
(
const
char
*
binpath
,
const
struct
bcc_elf_usdt
*
probe
)
{
Probe
*
found_probe
=
nullptr
;
for
(
Probe
*
p
:
probes_
)
{
for
(
auto
&
p
:
probes_
)
{
if
(
p
->
provider_
==
probe
->
provider
&&
p
->
name_
==
probe
->
name
)
{
found_probe
=
p
;
break
;
p
->
add_location
(
probe
->
pc
,
probe
->
arg_fmt
)
;
return
;
}
}
if
(
!
found_probe
)
{
found_probe
=
new
Probe
(
binpath
,
probe
->
provider
,
probe
->
name
,
probe
->
semaphore
);
probes_
.
push_back
(
found_probe
);
}
found_probe
->
add_location
(
probe
->
pc
,
probe
->
arg_fmt
);
probes_
.
emplace_back
(
new
Probe
(
binpath
,
probe
->
provider
,
probe
->
name
,
probe
->
semaphore
,
pid_
));
probes_
.
back
()
->
add_location
(
probe
->
pc
,
probe
->
arg_fmt
);
}
std
::
string
Context
::
resolve_bin_path
(
const
std
::
string
&
bin_path
)
{
...
...
@@ -236,8 +229,8 @@ std::string Context::resolve_bin_path(const std::string &bin_path) {
return
result
;
}
Probe
*
Context
::
get
(
const
std
::
string
&
probe_name
)
const
{
for
(
Probe
*
p
:
probes_
)
{
std
::
shared_ptr
<
Probe
>
Context
::
get
(
const
std
::
string
&
probe_name
)
{
for
(
auto
&
p
:
probes_
)
{
if
(
p
->
name_
==
probe_name
)
return
p
;
}
...
...
@@ -246,8 +239,8 @@ Probe *Context::get(const std::string &probe_name) const {
bool
Context
::
generate_usdt_args
(
std
::
ostream
&
stream
)
{
stream
<<
"#include <uapi/linux/ptrace.h>
\n
"
;
for
(
auto
&
p
:
u
probes_
)
{
if
(
!
p
.
first
->
usdt_getarg
(
stream
,
p
.
second
,
pid_
))
for
(
auto
&
p
:
probes_
)
{
if
(
p
->
enabled
()
&&
!
p
->
usdt_getarg
(
stream
))
return
false
;
}
return
true
;
...
...
@@ -255,23 +248,20 @@ bool Context::generate_usdt_args(std::ostream &stream) {
bool
Context
::
enable_probe
(
const
std
::
string
&
probe_name
,
const
std
::
string
&
fn_name
)
{
Probe
*
p
=
get
(
probe_name
);
if
(
!
p
)
if
(
pid_stat_
&&
pid_stat_
->
is_stale
())
return
false
;
if
(
p
->
need_enable
())
{
if
(
!
pid_
||
!
p
->
enable
(
pid_
.
value
()))
return
false
;
}
uprobes_
.
emplace_back
(
p
,
fn_name
);
return
true
;
auto
p
=
get
(
probe_name
);
return
p
&&
p
->
enable
(
fn_name
);
}
void
Context
::
each_uprobe
(
each_uprobe_cb
callback
)
{
for
(
auto
&
p
:
uprobes_
)
{
for
(
Probe
::
Location
&
loc
:
p
.
first
->
locations_
)
{
callback
(
p
.
first
->
bin_path_
.
c_str
(),
p
.
second
.
c_str
(),
loc
.
address_
,
for
(
auto
&
p
:
probes_
)
{
if
(
!
p
->
enabled
())
continue
;
for
(
Probe
::
Location
&
loc
:
p
->
locations_
)
{
callback
(
p
->
bin_path_
.
c_str
(),
p
->
attached_to_
->
c_str
(),
loc
.
address_
,
pid_
.
value_or
(
-
1
));
}
}
...
...
@@ -285,16 +275,15 @@ Context::Context(const std::string &bin_path) : loaded_(false) {
}
}
Context
::
Context
(
int
pid
)
:
pid_
(
pid
),
loaded_
(
false
)
{
Context
::
Context
(
int
pid
)
:
pid_
(
pid
),
pid_stat_
(
pid
),
loaded_
(
false
)
{
if
(
bcc_procutils_each_module
(
pid
,
_each_module
,
this
)
==
0
)
loaded_
=
true
;
}
Context
::~
Context
()
{
for
(
Probe
*
p
:
probes_
)
{
if
(
pid_
&&
p
->
enabled
())
p
->
disable
(
pid_
.
value
());
delete
p
;
if
(
pid_stat_
&&
!
pid_stat_
->
is_stale
())
{
for
(
auto
&
p
:
probes_
)
p
->
disable
();
}
}
}
...
...
src/cc/usdt.h
View file @
10436451
...
...
@@ -15,6 +15,7 @@
*/
#pragma once
#include <memory>
#include <string>
#include <unordered_map>
#include <vector>
...
...
@@ -127,32 +128,34 @@ class Probe {
};
std
::
vector
<
Location
>
locations_
;
std
::
unordered_map
<
int
,
uint64_t
>
semaphores_
;
std
::
unordered_map
<
int
,
ProcStat
>
enabled_semaphores
_
;
optional
<
int
>
pid
_
;
optional
<
bool
>
in_shared_object_
;
optional
<
std
::
string
>
attached_to_
;
optional
<
uint64_t
>
attached_semaphore_
;
std
::
string
largest_arg_type
(
size_t
arg_n
);
bool
add_to_semaphore
(
int
pid
,
int16_t
val
);
bool
resolve_global_address
(
uint64_t
*
global
,
const
uint64_t
addr
,
optional
<
int
>
pid
);
bool
lookup_semaphore_addr
(
uint64_t
*
address
,
int
pid
);
bool
add_to_semaphore
(
int16_t
val
);
bool
resolve_global_address
(
uint64_t
*
global
,
const
uint64_t
addr
);
bool
lookup_semaphore_addr
(
uint64_t
*
address
);
void
add_location
(
uint64_t
addr
,
const
char
*
fmt
);
public:
Probe
(
const
char
*
bin_path
,
const
char
*
provider
,
const
char
*
name
,
uint64_t
semaphore
);
uint64_t
semaphore
,
const
optional
<
int
>
&
pid
);
size_t
num_locations
()
const
{
return
locations_
.
size
();
}
size_t
num_arguments
()
const
{
return
locations_
.
front
().
arguments_
.
size
();
}
uint64_t
address
(
size_t
n
=
0
)
const
{
return
locations_
[
n
].
address_
;
}
bool
usdt_getarg
(
std
::
ostream
&
stream
,
const
std
::
string
&
fn_name
,
const
optional
<
int
>
&
pid
=
nullopt
);
bool
usdt_getarg
(
std
::
ostream
&
stream
);
bool
need_enable
()
const
{
return
semaphore_
!=
0x0
;
}
bool
enable
(
int
pid
);
bool
disable
(
int
pid
);
bool
enabled
()
const
{
return
!
enabled_semaphores_
.
empty
()
;
}
bool
enable
(
const
std
::
string
&
fn_name
);
bool
disable
();
bool
enabled
()
const
{
return
!
!
attached_to_
;
}
bool
in_shared_object
();
const
std
::
string
&
name
()
{
return
name_
;
}
...
...
@@ -163,9 +166,10 @@ public:
};
class
Context
{
std
::
vector
<
Probe
*
>
probes_
;
std
::
vector
<
std
::
pair
<
Probe
*
,
std
::
string
>>
uprobes_
;
std
::
vector
<
std
::
shared_ptr
<
Probe
>
>
probes_
;
optional
<
int
>
pid_
;
optional
<
ProcStat
>
pid_stat_
;
bool
loaded_
;
static
void
_each_probe
(
const
char
*
binpath
,
const
struct
bcc_elf_usdt
*
probe
,
...
...
@@ -184,8 +188,8 @@ public:
bool
loaded
()
const
{
return
loaded_
;
}
size_t
num_probes
()
const
{
return
probes_
.
size
();
}
Probe
*
get
(
const
std
::
string
&
probe_name
)
const
;
Probe
*
get
(
int
pos
)
const
{
return
probes_
[
pos
];
}
std
::
shared_ptr
<
Probe
>
get
(
const
std
::
string
&
probe_name
)
;
std
::
shared_ptr
<
Probe
>
get
(
int
pos
)
{
return
probes_
[
pos
];
}
bool
enable_probe
(
const
std
::
string
&
probe_name
,
const
std
::
string
&
fn_name
);
bool
generate_usdt_args
(
std
::
ostream
&
stream
);
...
...
tests/cc/test_usdt_probes.cc
View file @
10436451
...
...
@@ -39,8 +39,8 @@ TEST_CASE("test finding a probe in our own process", "[usdt]") {
REQUIRE
(
ctx
.
num_probes
()
>=
1
);
SECTION
(
"our test probe"
)
{
USDT
::
Probe
*
probe
=
ctx
.
get
(
"sample_probe_1"
);
REQUIRE
(
probe
!=
nullptr
);
auto
probe
=
ctx
.
get
(
"sample_probe_1"
);
REQUIRE
(
probe
);
REQUIRE
(
probe
->
in_shared_object
()
==
false
);
REQUIRE
(
probe
->
name
()
==
"sample_probe_1"
);
...
...
@@ -108,8 +108,8 @@ TEST_CASE("test listing all USDT probes in Ruby/MRI", "[usdt]") {
mri_probe_count
=
ctx
.
num_probes
();
SECTION
(
"GC static probe"
)
{
USDT
::
Probe
*
probe
=
ctx
.
get
(
"gc__mark__begin"
);
REQUIRE
(
probe
!=
nullptr
);
auto
probe
=
ctx
.
get
(
"gc__mark__begin"
);
REQUIRE
(
probe
);
REQUIRE
(
probe
->
in_shared_object
()
==
true
);
REQUIRE
(
probe
->
name
()
==
"gc__mark__begin"
);
...
...
@@ -122,8 +122,8 @@ TEST_CASE("test listing all USDT probes in Ruby/MRI", "[usdt]") {
}
SECTION
(
"object creation probe"
)
{
USDT
::
Probe
*
probe
=
ctx
.
get
(
"object__create"
);
REQUIRE
(
probe
!=
nullptr
);
auto
probe
=
ctx
.
get
(
"object__create"
);
REQUIRE
(
probe
);
REQUIRE
(
probe
->
in_shared_object
()
==
true
);
REQUIRE
(
probe
->
name
()
==
"object__create"
);
...
...
@@ -136,8 +136,8 @@ TEST_CASE("test listing all USDT probes in Ruby/MRI", "[usdt]") {
}
SECTION
(
"array creation probe"
)
{
USDT
::
Probe
*
probe
=
ctx
.
get
(
"array__create"
);
REQUIRE
(
probe
!=
nullptr
);
auto
probe
=
ctx
.
get
(
"array__create"
);
REQUIRE
(
probe
);
REQUIRE
(
probe
->
name
()
==
"array__create"
);
REQUIRE
(
probe
->
num_locations
()
==
7
);
...
...
@@ -158,8 +158,8 @@ TEST_CASE("test listing all USDT probes in Ruby/MRI", "[usdt]") {
REQUIRE
(
ctx
.
num_probes
()
>=
mri_probe_count
);
SECTION
(
"get probe in running process"
)
{
USDT
::
Probe
*
probe
=
ctx
.
get
(
"gc__mark__begin"
);
REQUIRE
(
probe
!=
nullptr
);
auto
probe
=
ctx
.
get
(
"gc__mark__begin"
);
REQUIRE
(
probe
);
REQUIRE
(
probe
->
in_shared_object
()
==
true
);
REQUIRE
(
probe
->
name
()
==
"gc__mark__begin"
);
...
...
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