hello all,
i found a warning during kernel build (5.3.11-rc1+). -----------------x----------x----------------- kernel/exit.o: warning: objtool: __x64_sys_exit_group()+0x14: unreachable instruction -------------------x---------------x-----------
Related details: ---------------
$uname -a Linux debian 5.3.11-rc1+ #6 SMP Tue Nov 12 01:23:06 IST 2019 x86_64 GNU/Linux $
$gcc --version gcc (Debian 9.2.1-14) 9.2.1 20191025 ------x---has-been-cut-here--x------
(gdb) l __x64_sys_exit_group 987 /* 988 * this kills every thread in the thread group. Note that any externally 989 * wait4()-ing process will get the correct exit code - even if this 990 * thread is not the thread group leader. 991 */ 992 SYSCALL_DEFINE1(exit_group, int, error_code) 993 { 994 do_group_exit((error_code & 0xff) << 8); 995 /* NOTREACHED */ 996 return 0; (gdb)
(gdb) l *__x64_sys_exit_group+0x14 0xffffffff81085404 is in __x64_sys_exit_group (kernel/exit.c:996). 991 */ 992 SYSCALL_DEFINE1(exit_group, int, error_code) 993 { 994 do_group_exit((error_code & 0xff) << 8); 995 /* NOTREACHED */ 996 return 0; 997 } 998 999 struct waitid_info { 1000 pid_t pid; (gdb)
(gdb) l *__x64_sys_exit_group 0xffffffff810853f0 is in __x64_sys_exit_group (kernel/exit.c:992). 987 /* 988 * this kills every thread in the thread group. Note that any externally 989 * wait4()-ing process will get the correct exit code - even if this 990 * thread is not the thread group leader. 991 */ 992 SYSCALL_DEFINE1(exit_group, int, error_code) 993 { 994 do_group_exit((error_code & 0xff) << 8); 995 /* NOTREACHED */ 996 return 0; (gdb)
--------------------x-------------x-----------------------------
objdump -r -S -l --disassemble kernel/exit.o output is attached
-- software engineer rajagiri school of engineering and technology