内容简介
#include <sys/prctl.h>int prctl(int%uA0option, unsigned long%uA0arg2, unsigned long%uA0arg3%uA0, unsigned long%uA0arg4, unsigned long%uA0arg5)
描述
prctl() is called with a first argument describing what to do (with values defined in <linux/prctl.h>), and further parameters with a significance depending on the first one. The first argument can be:| 标签 | 描述 |
|---|---|
| PR_SET_PDEATHSIG | |
| %uA0 | (since Linux 2.1.57) Set the parent process death signal of the current process to%uA0arg2%uA0(either a signal value in the range 1..maxsig, or 0 to clear). This is the signal that the current process will get when its parent dies. This value is cleared upon a%uA0fork(). |
| PR_GET_PDEATHSIG | |
| %uA0 | (since Linux 2.3.15) Read the current value of the parent process death signal into the (int *)%uA0arg2. |
| PR_SET_DUMPABLE | |
| %uA0 | (Since Linux 2.4) Set the state of the flag determining whether core dumps are produced for this process upon delivery of a signal whose default behaviour is to produce a core dump. (Normally this flag is set for a process by default, but it is cleared when a set-user-ID or set-group-ID program is executed and also by various system calls that manipulate process UIDs and GIDs). In kernels up to and including 2.6.12,arg2%uA0must be either 0 (process is not dumpable) or 1 (process is dumpable). Since kernel 2.6.13, the value 2 is also permitted this causes any binary which normally would not be dumped to be dumped readable by root only. (See also the description of/proc/sys/fs/suid_dumpable%uA0in%uA0proc(5).) |
| PR_GET_DUMPABLE | |
| %uA0 | (Since Linux 2.4) Return (as the function result) the current state of the calling process’s dumpable flag. |
| PR_SET_KEEPCAPS | |
| %uA0 | Set the state of the process’s "keep capabilities" flag, which determines whether the process’s effective and permitted capability sets are cleared when a change is made to the process’s user IDs such that the process’s real UID, effective UID, and saved set-user-ID all become non-zero when at least one of them previously had the value 0. (By default, these credential sets are cleared).%uA0arg2%uA0must be either 0 (capabilities are cleared) or 1 (capabilities are kept). |
| PR_GET_KEEPCAPS | |
| %uA0 | Return (as the function result) the current state of the calling process’s "keep capabilities" flag. |
返回值
PR_GET_DUMPABLE%uA0and%uA0PR_GET_KEEPCAPS%uA0return 0 or 1 on success. All other%uA0optionvalues return 0 on success. On error, -1 is returned, and%uA0errno%uA0is set appropriately.错误
| 标签 | 描述 |
|---|---|
| EINVAL | The value of%uA0option%uA0is not recognized, or it isPR_SET_PDEATHSIG%uA0and%uA0arg2%uA0is not zero or a signal number. |
遵循于
This call is Linux-specific. IRIX has a%uA0prctl() system call (also introduced in Linux 2.1.44 as irix_prctl on the MIPS architecture), with prototypeptrdiff_t prctl(int%uA0option, int%uA0arg2, int%uA0arg3)
and options to get the maximum number of processes per user, get the maximum number of processors the calling process can use, find out whether a specified process is currently blocked, get or set the maximum stack size, etc.