目錄用戶用戶管理查詢所有用戶查看當前用戶查看當前連接數創建用戶刪除用戶修改密碼規則查看規則/策略規則說明臨時設置持久設置修改密碼許可權資料庫提供的 許可權列表查看許可權給用戶授權回收用戶許可權 用戶 用戶管理 mysql用戶管理位於資料庫mysql中的user表中 mysql> show tables; + ...
[20240920]跟蹤library cache lock library cache pin使用gdb.txt
--//前一陣子，寫的使用gdb跟蹤library cache lock library cache pin的腳本有一個小問題，無法獲得lock address以及pin address
--//地址,有一點點小缺陷，嘗試修改完善看看。
--//按照https://nenadnoveljic.com/blog/tracing-library-cache-locks/介紹：
In order to close this gap I, first, examined the following two Oracle C functions on the release 19.6.0.0.200114:
kgllkal and kglGetSO.
kgllkal allocates a library cache lock. It receives the following arguments:
rdx: handle address
rcx: lock mode
Further, it calls kglGetSO to allocate the library cache state object. kglGetSO returns the lock address.
--//按照介紹調用kglGetSO返回lock address.我猜測 library cache pind的pin地址也是類似的情況。
$ ./lookup.awk kglGetSO
kglGetSO : kernel generic library cache management get state object
--//如何使用gdb實現，自己嘗試看看。
--//仔細看鏈接https://nenadnoveljic.com/blog/tracing-library-cache-locks/
pid$target:oracle:kglGetSO:return
/ self->kglGetSO /
{
printf("\n");
printf("KGLLKHDL KGLLKMOD KGLLKADR\n");
printf("-------- -------- --------\n");
printf("%X %8d %X\n" , self->kgllkhdl, self->kgllkmod, arg1 );
printf("\n");
printf("==========================\n");
printf("\n");
self->kglGetSO = 0;
}
--//dtrace可以設置在kglGetSO return獲取arg1就是KGLLKADR，gdb如何實現呢？想起測試學習使用的方法，建立一個過程lcp加入sleep 3600，
--//先執行它，然後打開另外一個會話編譯它，就會出現library cache pin，再打開另外的會話編譯它，就會出現library cache lock，使用它
--//測試看看。
1.環境：
SCOTT@book01p> @ver2
==============================
PORT_STRING : x86_64/Linux 2.4.xx
VERSION : 21.0.0.0.0
BANNER : Oracle Database 21c Enterprise Edition Release 21.0.0.0.0 - Production
BANNER_FULL : Oracle Database 21c Enterprise Edition Release 21.0.0.0.0 - Production
Version 21.3.0.0.0
BANNER_LEGACY : Oracle Database 21c Enterprise Edition Release 21.0.0.0.0 - Production
CON_ID : 0
PL/SQL procedure successfully completed.
SYS@book> @ sed "library cache pin"
SYS@book> @ pr
==============================
SED_EVENT# : 375
SED_NAME : library cache pin
SED_WAIT_CLASS : Concurrency
SED_P1 : handle address
SED_P2 : pin address
SED_P3 : 100*mode+namespace
SED_EQ_NAME :
SED_REQ_REASON :
SED_REQ_DESCRIPTION :
PL/SQL procedure successfully completed.
--//library cache lock類似
--//grant execute on sys.dbms_lock to scott;
create procedure lcp
is
begin
sys.dbms_lock.sleep(3600);
end;
/
2.測試1：
--//session 1:
SCOTT@book01p(412,5770)> exec lcp
--//session 2:
SCOTT@book01p(148,4168)> set timing on
SCOTT@book01p(148,4168)> alter procedure lcp compile;
--//掛起!!
SYS@book> @ ashtop event,p1hex,p2hex,p2,p3hex 1=1 &10s
Total Distinct Distinct Distinct
Seconds AAS %This EVENT P1HEX P2HEX P2 P3HEX FIRST_SEEN LAST_SEEN Execs Seen Tstamps Execs Seen1
--------- ------- ------- ------------------------------------------ ----------------- ----------------- ---------- ----------------- ------------------- ------------------- ---------- -------- -----------
10 1.0 83% | library cache pin 00000000635F4DA0 000000006C0DCDD8 1812843992 00012A0300010003 2024-09-20 16:59:23 2024-09-20 16:59:32 1 10 1
2 .2 17% | 0 2024-09-20 16:59:23 2024-09-20 16:59:31 1 2 2
--//出現library cache pin等待事件，P1hex=00000000635F4DA0就是對象句柄。
$ source ext_kglobj.sh 00000000635F4DA0
(gdb) 0x635f4f68: "LCPSCOTTBOOK01P"
(gdb) quit
--//使用我前面寫的抽取對象腳本ext_kglobj.sh，可以發現就是對象lcp。中斷上面的執行。
3.編寫腳本如下：
$ cat lkpn.gdb2
set pagination off
set logging file /tmp/lkpn.log
set logging overwrite on
set logging on
set $lk = 0
set $pn = 0
set $lock = 0
#break kglpnal if $rcx==3
break kglpnal if ($rcx=3 && $rdx=0x00000000635F4DA0)
commands
silent
printf "kglpnal count %02d -- handle address: %016x, mode: %d ", ++$pn ,$rdx ,$rcx
echo kglnaobj address:
x/s $rdx+0x1c8
c
end
break kglGetSO
commands
silent
finish
end
--//註：設置斷點在句柄$rdx=0x00000000635F4DA0，kglGetSO執行最後是finish，這樣停止在該函數kglGetSO的返回。
4.繼續測試：
--//session 2:
SCOTT@book01p(148,4168)> @ spid
SID SERIAL# PROCESS SERVER SPID PID P_SERIAL# C50
---------- ---------- ------------------------ --------- ------------------------------ ------- ---------- --------------------------------------------------
148 4168 5283 DEDICATED 5285 69 14 alter system kill session '148,4168' immediate;
--//獲得session 2的spid=5285。
--//window 1：
$ rlgdb -f -p 5285 -x lkpn.gdb2
...
/usr/src/debug/glibc-2.17-c758a686/sysdeps/unix/syscall-template.S:81:3374:beg:0x7f35cf359480
Breakpoint 1 at 0x1536c020
Breakpoint 2 at 0x1536f9c0
--//重覆前面的測試：
--//window 1,不停按c繼續，直到出現：
(gdb) c
Continuing.
0x0000000015367fbe in kgllkal ()
(gdb) c
Continuing.
0x0000000015367fbe in kgllkal ()
(gdb) c
Continuing.
0x000000001536c16a in kglpnal ()
(gdb) c
....
(gdb) c
Continuing.
kglpnal count 01 -- handle address: 00000000635f4da0, mode: 3 kglnaobj address:0x635f4f68: "LCPSCOTTBOOK01P"
0x000000001536c16a in kglpnal ()
--//session 3:
SYS@book> @ ashtop event,p1hex,p2hex,p2,p3hex 1=1 &10s
Total Distinct Distinct Distinct
Seconds AAS %This EVENT P1HEX P2HEX P2 P3HEX FIRST_SEEN LAST_SEEN Execs Seen Tstamps Execs Seen1
--------- ------- ------- ------------------------------------------ ----------------- ----------------- ---------- ----------------- ------------------- ------------------- ---------- -------- -----------
10 1.0 77% | 1 2024-09-20 18:00:02 2024-09-20 18:00:11 1 10 1
3 .3 23% | 0 2024-09-20 18:00:03 2024-09-20 18:00:08 1 2 2
--//沒有獲得相應等待事件。
--//window 1:
(gdb) c
Continuing.
kglpnal count 01 -- handle address: 00000000635f4da0, mode: 3 kglnaobj address:0x635f4f68: "LCPSCOTTBOOK01P"
0x000000001536c16a in kglpnal ()
--//現在停在函數kglGetSO的返回處。記住停止在地址：0x000000001536c16a
(gdb) info regi
rax 0x6c09abb8 1812573112
rbx 0x0 0
rcx 0x71fa9128 1912246568
rdx 0x6c09abb8 1812573112
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
rsi 0x71fbca40 1912326720
rdi 0x3 3
rbp 0x7ffd091a1540 0x7ffd091a1540
rsp 0x7ffd091a1120 0x7ffd091a1120
r8 0x7f35d2e33570 139869148099952
r9 0x6fb37c20 1874033696
r10 0x76c84268 1992835688
r11 0x3 3
r12 0x6c297cc8 1814658248
r13 0x7f35d2dee060 139869147816032
r14 0x635f4da0 1667190176
r15 0x3 3
rip 0x1536c16a 0x1536c16a <kglpnal+330>
eflags 0x246 [ PF ZF IF ]
cs 0x33 51
ss 0x2b 43
ds 0x0 0
es 0x0 0
fs 0x0 0
gs 0x0 0
(gdb) c
Continuing.
Program received signal SIGUSR2, User defined signal 2.
0x00007f35cee68fca in semtimedop () at ../sysdeps/unix/syscall-template.S:81
/usr/src/debug/glibc-2.17-c758a686/sysdeps/unix/syscall-template.S:81:3374:beg:0x7f35cee68fca
--//session 3:
SYS@book> @ ashtop event,p1hex,p2hex,p2,p3hex 1=1 &10s
Total Distinct Distinct Distinct
Seconds AAS %This EVENT P1HEX P2HEX P2 P3HEX FIRST_SEEN LAST_SEEN Execs Seen Tstamps Execs Seen1
--------- ------- ------- ------------------------------------------ ----------------- ----------------- ---------- ----------------- ------------------- ------------------- ---------- -------- -----------
9 .9 64% | 1 2024-09-20 18:02:13 2024-09-20 18:02:22 2 9 2
2 .2 14% | library cache pin 00000000635F4DA0 000000006C09ABB8 1812573112 00012A0300010003 2024-09-20 18:02:21 2024-09-20 18:02:22 1 2 1
2 .2 14% | 0 2024-09-20 18:02:14 2024-09-20 18:02:17 1 2 2
--//P2hex=000000006C09ABB8,正好是前面rdx=0x6c09abb8對上，實際上這個就是pin address地址。
--//p3hex=00012A0300010003,100*mode+namespace,這裡稍微有點不同，前面8位，00012A03 = 76291對應lcp的object_id.
--//mode=0003，namespace=0001。
SCOTT@book01p> @ o2 lcp
owner object_name object_type SEG_PART_NAME status OID D_OID CREATED LAST_DDL_TIME
----- ----------- ----------- ------------- --------- ----- ----- ------------------- -------------------
SCOTT LCP PROCEDURE VALID 76291 2024-08-18 11:51:35 2024-09-21 12:07:05
SYS@book> @nmsp procedure -1
@ nmsp table -1
@ nmsp '' 74 or @ nmsp '' 0x4a|x4a
KGLSTDSC KGLSTIDN KGLSTIDN_HEX
--------------- -------- ------------
TABLE/PROCEDURE 1 1
--//有了前面的信息，改寫腳本如下：
$ cat lkpn.gdb2
set pagination off
set logging file /tmp/lkpn.log
set logging overwrite on
set logging on
set $lk = 0
set $pn = 0
set $lock = 0
#break kgllkal if $rcx==3
#break kgllkal if ( $rcx==3 && $rdx==0x00000000670C9E58 )
#break kgllkal if $rdx==0x00000000670C9E58
break kgllkal
condition 1
commands
silent
printf "kgllkal count %02d -- handle address: %016x, mode: %d ", ++$lk ,$rdx ,$rcx
echo kglnaobj address:
x/s $rdx+0x1c8
c
end
#break kglpnal if $rcx==3
#break kglpnal if $rdx==0x00000000635F4DA0
break kglpnal
commands
silent
printf "kglpnal count %02d -- handle address: %016x, mode: %d ", ++$pn ,$rdx ,$rcx
echo kglnaobj address:
x/s $rdx+0x1c8
c
end
#break kglGetSO
#commands
# silent
# finish
#end
break *0x0000000015367fbe
commands
silent
printf "kglGetS0 return lock address : %016x\n", $rdx
c
end
break *0x1536c16a
commands
silent
printf "kglGetS0 return pin address : %016x\n", $rdx
c
end
--//註：調用kgllkal在調用kglGetS0的返回停止在0x15367fbe地址時，對應寄存器rdx的就是lock地址(猜測)。
4.繼續測試，驗證lock address是否正確。
--//session 3,再打開新的會話：
SCOTT@book01p(272,12390)> @spid
SID SERIAL# PROCESS SERVER SPID PID P_SERIAL# C50
---------- ---------- ------------------------ --------- ------------------------------ ------- ---------- --------------------------------------------------
272 12390 6427 DEDICATED 6429 70 20 alter system kill session '272,12390' immediate;
--//window 1：
$ rlgdb -f -p 6429 -x lkpn.gdb2
...
/usr/src/debug/glibc-2.17-c758a686/sysdeps/unix/syscall-template.S:81:3374:beg:0x7f931703e480
Breakpoint 1 at 0x15367e90
Breakpoint 2 at 0x1536c020
Breakpoint 3 at 0x15367fbe
Breakpoint 4 at 0x1536c16a
(gdb) c
--//重覆前面的測試，只不過這次是3個會話。
--//session 1:
SCOTT@book01p(412,5770)> exec lcp
--//session 2:
SCOTT@book01p(148,4168)> set timing on
SCOTT@book01p(148,4168)> alter procedure lcp compile;
--//掛起!!
--//session 4:
SCOTT@book01p(272,12390)> set timing on
SCOTT@book01p(272,12390)> alter procedure lcp compile;
--//掛起!!
--//window 1：
(gdb) c
Continuing.
kgllkal count 01 -- handle address: 0000000063cb7b20, mode: 1 kglnaobj address:0x63cb7ce8: "alter procedure lcp compile"
kglGetS0 lock address : 0000000063634090
kgllkal count 02 -- handle address: 000000006134f840, mode: 1 kglnaobj address:0x6134fa08: ""
kglGetS0 lock address : 00000000610c6b90
kglpnal count 01 -- handle address: 000000006134f840, mode: 3 kglnaobj address:0x6134fa08: ""
kglGetS0 pin address : 00000000610c6d70
kgllkal count 03 -- handle address: 00000000702d5908, mode: 2 kglnaobj address:0x702d5ad0: "bookSYSCDB$ROOT"
kglGetS0 lock address : 00000000610c6c80
kgllkal count 04 -- handle address: 000000006b97c9f8, mode: 2 kglnaobj address:0x6b97cbc0: "1073777561SYSCDB$ROOT"
kglGetS0 lock address : 0000000063633eb0
kgllkal count 05 -- handle address: 0000000069c6b610, mode: 1 kglnaobj address:0x69c6b7d8: "e985fc239b919877f25909e8f398a456Child:2BOOK01P"
kglGetS0 lock address : 0000000063633dc0
kglpnal count 02 -- handle address: 0000000069c6b610, mode: 3 kglnaobj address:0x69c6b7d8: "e985fc239b919877f25909e8f398a456Child:2BOOK01P"
kglGetS0 pin address : 00000000610c6aa0
kgllkal count 06 -- handle address: 0000000060d45130, mode: 1 kglnaobj address:0x60d452f8: "SCOTTBOOK01P"
kglGetS0 lock address : 0000000063633dc0
kgllkal count 07 -- handle address: 00000000702d5908, mode: 2 kglnaobj address:0x702d5ad0: "bookSYSCDB$ROOT"
kglGetS0 lock address : 00000000610c6d70
kgllkal count 08 -- handle address: 000000006b97c9f8, mode: 2 kglnaobj address:0x6b97cbc0: "1073777561SYSCDB$ROOT"
kglGetS0 lock address : 00000000610c6c80
kglpnal count 03 -- handle address: 00000000697c1220, mode: 2 kglnaobj address:0x697c13e8: "DATABASESYSBOOK01P"
kglGetS0 pin address : 00000000610c6d70
kglpnal count 04 -- handle address: 00000000697c1220, mode: 2 kglnaobj address:0x697c13e8: "DATABASESYSBOOK01P"
kglGetS0 pin address : 00000000610c6d70
kgllkal count 09 -- handle address: 0000000067570378, mode: 1 kglnaobj address:0x67570540: "LOGMNRGGC_TRIGGERSYSBOOK01P"
kglGetS0 lock address : 00000000610c6c80
kglpnal count 05 -- handle address: 0000000067570378, mode: 2 kglnaobj address:0x67570540: "LOGMNRGGC_TRIGGERSYSBOOK01P"
kglGetS0 pin address : 0000000063633eb0
kgllkal count 10 -- handle address: 00000000674b5f50, mode: 1 kglnaobj address:0x674b6118: "NO_VM_DDLWMSYSBOOK01P"
kglGetS0 lock address : 00000000610c6c80
kglpnal count 06 -- handle address: 00000000674b5f50, mode: 2 kglnaobj address:0x674b6118: "NO_VM_DDLWMSYSBOOK01P"
kglGetS0 pin address : 0000000063633eb0
kgllkal count 11 -- handle address: 0000000066fe8790, mode: 1 kglnaobj address:0x66fe8958: "LBAC$BEFORE_ALTERLBACSYSBOOK01P"
kglGetS0 lock address : 00000000610c6c80
kglpnal count 07 -- handle address: 0000000066fe8790, mode: 2 kglnaobj address:0x66fe8958: "LBAC$BEFORE_ALTERLBACSYSBOOK01P"
kglGetS0 pin address : 0000000063633eb0
kgllkal count 12 -- handle address: 00000000635f4da0, mode: 1 kglnaobj address:0x635f4f68: "LCPSCOTTBOOK01P"
kglGetS0 lock address : 00000000610c6d70
kgllkal count 13 -- handle address: 00000000635f4da0, mode: 3 kglnaobj address:0x635f4f68: "LCPSCOTTBOOK01P"
kglGetS0 lock address : 00000000610c6d70
--//對象LCPSCOTTBOOK01P ，session 4先調用kgllkal mode=1，因為session 2出現library cache pin的mode=3，無法獲取，出現
--//library cache lock等待事件，mode=3.
Program received signal SIGUSR2, User defined signal 2.
0x00007f9316b4dfca in semtimedop () at ../sysdeps/unix/syscall-template.S:81
/usr/src/debug/glibc-2.17-c758a686/sysdeps/unix/syscall-template.S:81:3374:beg:0x7f9316b4dfca
--//進入休眠，每3秒探測1次。
SYS@book> @ ashtop event,p1hex,p2hex,p2,p3hex 1=1 &10s
Total Distinct Distinct Distinct
Seconds AAS %This EVENT P1HEX P2HEX P2 P3HEX FIRST_SEEN LAST_SEEN Execs Seen Tstamps Execs Seen1
--------- ------- ------- ------------------------------------------ ----------------- ----------------- ---------- ----------------- ------------------- ------------------- ---------- -------- -----------
10 1.0 48% | library cache lock 00000000635F4DA0 00000000610C6D70 1628204400 00012A0300010003 2024-09-20 18:22:19 2024-09-20 18:22:28 1 10 1
10 1.0 48% | library cache pin 00000000635F4DA0 000000006198F7B0 1637414832 00012A0300010003 2024-09-20 18:22:19 2024-09-20 18:22:28 1 10 1
1 .1 5% | 0 2024-09-20 18:22:20 2024-09-20 18:22:20 1 1 1
--//可以發現等待事件library cache lock的P2的信息完全可以對上。
5.簡單小結：
--//通過調用kglGetSO的返回獲得library cache lock/library cache pin的lock pin address。
--//gdb不知道如何寫在kglGetSO的返回處獲得相應地址，只能使用硬代碼獲得相應寄存器信息，那位知道gdb如何寫。
