[20210222]gdb ptrace Operation not permitted.txt

[20210222]gdb ptrace Operation not permitted.txt

--//嘗試使用gdb除錯,發現如下錯誤.
$ gdb -p 59148
GNU gdb (GDB) Red Hat Enterprise Linux 7.6.1-119.0.1.el7
Copyright (C) 2013 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.  Type "show copying"
and "show warranty" for details.
This GDB was configured as "x86_64-redhat-linux-gnu".
For bug reporting instructions, please see:
<
Attaching to process 59148
ptrace: Operation not permitted.
(gdb) quit

--//上網查了一下,都是報2個gdb程式attach的情況,還有就是有人使用strace.我這種情況不存在.
--//還有一種情況我這裡也不存在.連結
https://blog.csdn.net/fjh1997/article/details/101881649
解決gdb除錯在WSL環境下報錯"ptrace: Operation not permitted"

需要把下列檔案裡面的變數改成0(原來是1)
echo 0 > /proc/sys/kernel/yama/ptrace_scope
或者
echo kernel.yama.ptrace_scope = 0 > /etc/sysctl.d/10-ptrace.conf #這個是持久化

--//主動使用strace跟蹤發現:
87442 open("/proc/26016/status", O_RDONLY) = 7
87442 fstat(7, {st_mode=S_IFREG|0444, st_size=0, ...}) = 0
87442 mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f6ff8db4000
87442 read(7, "Name:\toracle_26016_dy\nUmask:\t002"..., 1024) = 1024
87442 close(7)                          = 0
87442 munmap(0x7f6ff8db4000, 4096)      = 0
87442 rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
87442 write(2, "ptrace: Operation not permitted.", 32) = 32
87442 write(2, "\n", 1)                 = 1
--//應該是執行到下劃線時報錯.
$ man rt_sigprocmask
SIGPROCMASK(2)           Linux Programmer's Manual      SIGPROCMASK(2)

NAME
       sigprocmask - examine and change blocked signals


# cat /proc/76821/status  | head
Name:   oracle_76821_dy
Umask:  0022
State:  S (sleeping)
Tgid:   76821
Ngid:   0
Pid:    76821
PPid:   1
TracerPid:      0
Uid:    1000    1001    1001    1001
Gid:    1001    1004    1004    1004

--//我對比發現多了1個Umask(與11g),注意name不再是oracle,而是變成了oracle_程式號_sid前2個字元.

49971 open("/proc/49969/status", O_RDONLY) = 7
49971 fstat(7, {st_mode=S_IFREG|0444, st_size=0, ...}) = 0
49971 mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f201cd3f000
49971 read(7, "Name:\toracle\nState:\tt (tracing s"..., 1024) = 1024
49971 close(7)                          = 0
49971 munmap(0x7f201cd3f000, 4096)      = 0
49971 wait4(49969, [{WIFSTOPPED(s) && WSTOPSIG(s) == SIGSTOP}], 0, NULL) = 49969
49971 fcntl(0, F_GETFL)                 = 0x8002 (flags O_RDWR|O_LARGEFILE)
49971 ioctl(0, SNDCTL_TMR_TIMEBASE or TCGETS, {B38400 opost isig icanon echo ...}) = 0
49971 ioctl(0, TIOCGPGRP, [49970])      = 0
49971 ioctl(0, SNDCTL_TMR_TIMEBASE or TCGETS, {B38400 opost isig icanon echo ...}) = 0
49971 rt_sigprocmask(SIG_BLOCK, [CHLD], [], 8) = 0
49971 rt_sigaction(SIGINT, {0x45daa0, [INT], SA_RESTORER|SA_RESTART, 0x3799030330}, {0x524e30, [INT], SA_RESTORER|SA_RESTART, 0x3799030330}, 8) = 0
49971 rt_sigaction(SIGINT, {0x524e30, [INT], SA_RESTORER|SA_RESTART, 0x3799030330}, {0x45daa0, [INT], SA_RESTORER|SA_RESTART, 0x3799030330}, 8) = 0
49971 rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0
49971 brk(0x2dd4000)                    = 0x2dd4000
49971 ptrace(PTRACE_GETREGS, 49969, 0, 0x7fff445538c0) = 0

--//換成root使用者執行gdb,OK. 再次使用strace 跟蹤,注不知道為什麼不能加入-f引數.

open("/proc/89651/status", O_RDONLY)    = 7
fstat(7, {st_mode=S_IFREG|0444, st_size=0, ...}) = 0
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f93c8df0000
read(7, "Name:\toracle_89651_dy\nUmask:\t002"..., 1024) = 1024
close(7)                                = 0
munmap(0x7f93c8df0000, 4096)            = 0
wait4(89651, [{WIFSTOPPED(s) && WSTOPSIG(s) == SIGSTOP}], 0, NULL) = 89651
rt_sigprocmask(SIG_BLOCK, [CHLD], [], 8) = 0
rt_sigaction(SIGINT, {sa_handler=0x6ce6a0, sa_mask=[INT], sa_flags=SA_RESTORER|SA_RESTART, sa_restorer=0x7f93c6a0f400}, {sa_handler=0x5e5aa0, sa_mask=[INT], sa_flags=SA_RESTORER|SA_RESTART, sa_restorer=0x7f93c6a0f400}, 8) = 0
rt_sigaction(SIGINT, {sa_handler=0x5e5aa0, sa_mask=[INT], sa_flags=SA_RESTORER|SA_RESTART, sa_restorer=0x7f93c6a0f400}, {sa_handler=0x6ce6a0, sa_mask=[INT], sa_flags=SA_RESTORER|SA_RESTART, sa_restorer=0x7f93c6a0f400}, 8) = 0
rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0

--//僅僅確定執行rt_sigprocmask時報錯.也許是許可權的問題.