mirror of https://github.com/mkerrisk/man-pages
prctl.2: srcfix: add comments for navigation
The prctl.2 source is unnecessarily hard to navigate, not least because prctl option flags are traditionally named PR_* and so look just like prctl names. For each actual prctl, add a comment of the form .\" prctl PR_FOO to make it move obvious where each top-level prctl starts. Of course, we could add some clever macros, but let's not confuse dumb parsers. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
This commit is contained in:
parent
ec5cb536b1
commit
667eb3ac39
48
man2/prctl.2
48
man2/prctl.2
|
@ -77,6 +77,7 @@ is called with a first argument describing what to do
|
|||
arguments with a significance depending on the first one.
|
||||
The first argument can be:
|
||||
.\"
|
||||
.\" prctl PR_CAP_AMBIENT
|
||||
.TP
|
||||
.BR PR_CAP_AMBIENT " (since Linux 4.3)"
|
||||
.\" commit 58319057b7847667f0c9585b9de0e8932b0fdb08
|
||||
|
@ -130,6 +131,7 @@ library in the form of
|
|||
.BR cap_set_ambient (3),
|
||||
and
|
||||
.BR cap_reset_ambient (3).
|
||||
.\" prctl PR_CAPBSET_READ
|
||||
.TP
|
||||
.BR PR_CAPBSET_READ " (since Linux 2.6.25)"
|
||||
Return (as the function result) 1 if the capability specified in
|
||||
|
@ -152,6 +154,7 @@ A higher-level interface layered on top of this operation is provided in the
|
|||
.BR libcap (3)
|
||||
library in the form of
|
||||
.BR cap_get_bound (3).
|
||||
.\" prctl PR_CAPBSET_DROP
|
||||
.TP
|
||||
.BR PR_CAPBSET_DROP " (since Linux 2.6.25)"
|
||||
If the calling thread has the
|
||||
|
@ -178,6 +181,7 @@ A higher-level interface layered on top of this operation is provided in the
|
|||
.BR libcap (3)
|
||||
library in the form of
|
||||
.BR cap_drop_bound (3).
|
||||
.\" prctl PR_SET_CHILD_SUBREAPER
|
||||
.TP
|
||||
.BR PR_SET_CHILD_SUBREAPER " (since Linux 3.4)"
|
||||
.\" commit ebec18a6d3aa1e7d84aab16225e87fd25170ec2b
|
||||
|
@ -224,11 +228,13 @@ Some
|
|||
frameworks (e.g.,
|
||||
.BR systemd (1))
|
||||
employ a subreaper process for similar reasons.
|
||||
.\" prctl PR_GET_CHILD_SUBREAPER
|
||||
.TP
|
||||
.BR PR_GET_CHILD_SUBREAPER " (since Linux 3.4)"
|
||||
Return the "child subreaper" setting of the caller,
|
||||
in the location pointed to by
|
||||
.IR "(int\ *) arg2" .
|
||||
.\" prctl PR_SET_DUMPABLE
|
||||
.TP
|
||||
.BR PR_SET_DUMPABLE " (since Linux 2.3.20)"
|
||||
Set the state of the "dumpable" attribute,
|
||||
|
@ -297,6 +303,7 @@ the ownership of files in the process's
|
|||
.IR /proc/[pid]
|
||||
directory is affected as described in
|
||||
.BR proc (5).
|
||||
.\" prctl PR_GET_DUMPABLE
|
||||
.TP
|
||||
.BR PR_GET_DUMPABLE " (since Linux 2.3.20)"
|
||||
Return (as the function result) the current state of the calling
|
||||
|
@ -304,6 +311,7 @@ process's dumpable attribute.
|
|||
.\" Since Linux 2.6.13, the dumpable flag can have the value 2,
|
||||
.\" but in 2.6.13 PR_GET_DUMPABLE simply returns 1 if the dumpable
|
||||
.\" flags has a nonzero value. This was fixed in 2.6.14.
|
||||
.\" prctl PR_SET_ENDIAN
|
||||
.TP
|
||||
.BR PR_SET_ENDIAN " (since Linux 2.6.18, PowerPC only)"
|
||||
Set the endian-ness of the calling process to the value given
|
||||
|
@ -314,11 +322,13 @@ in \fIarg2\fP, which should be one of the following:
|
|||
or
|
||||
.B PR_ENDIAN_PPC_LITTLE
|
||||
(PowerPC pseudo little endian).
|
||||
.\" prctl PR_GET_ENDIAN
|
||||
.TP
|
||||
.BR PR_GET_ENDIAN " (since Linux 2.6.18, PowerPC only)"
|
||||
Return the endian-ness of the calling process,
|
||||
in the location pointed to by
|
||||
.IR "(int\ *) arg2" .
|
||||
.\" prctl PR_SET_FP_MODE
|
||||
.TP
|
||||
.BR PR_SET_FP_MODE " (since Linux 4.0, only on MIPS)"
|
||||
.\" commit 9791554b45a2acc28247f66a5fd5bbc212a6b8c8
|
||||
|
@ -425,6 +435,7 @@ The arguments
|
|||
and
|
||||
.IR arg5
|
||||
are ignored.
|
||||
.\" prctl PR_GET_FP_MODE
|
||||
.TP
|
||||
.BR PR_GET_FP_MODE " (since Linux 4.0, only on MIPS)"
|
||||
Return (as the function result)
|
||||
|
@ -442,6 +453,7 @@ The arguments
|
|||
and
|
||||
.IR arg5
|
||||
are ignored.
|
||||
.\" prctl PR_SET_FPEMU
|
||||
.TP
|
||||
.BR PR_SET_FPEMU " (since Linux 2.4.18, 2.5.9, only on ia64)"
|
||||
Set floating-point emulation control bits to \fIarg2\fP.
|
||||
|
@ -452,11 +464,13 @@ to silently emulate floating-point operation accesses, or
|
|||
to not emulate floating-point operations and send
|
||||
.B SIGFPE
|
||||
instead.
|
||||
.\" prctl PR_GET_FPEMU
|
||||
.TP
|
||||
.BR PR_GET_FPEMU " (since Linux 2.4.18, 2.5.9, only on ia64)"
|
||||
Return floating-point emulation control bits,
|
||||
in the location pointed to by
|
||||
.IR "(int\ *) arg2" .
|
||||
.\" prctl PR_SET_FPEXC
|
||||
.TP
|
||||
.BR PR_SET_FPEXC " (since Linux 2.4.21, 2.5.32, only on PowerPC)"
|
||||
Set floating-point exception mode to \fIarg2\fP.
|
||||
|
@ -470,11 +484,13 @@ Pass \fBPR_FP_EXC_SW_ENABLE\fP to use FPEXC for FP exception enables,
|
|||
\fBPR_FP_EXC_NONRECOV\fP for async nonrecoverable exception mode,
|
||||
\fBPR_FP_EXC_ASYNC\fP for async recoverable exception mode,
|
||||
\fBPR_FP_EXC_PRECISE\fP for precise exception mode.
|
||||
.\" prctl PR_GET_FPEXC
|
||||
.TP
|
||||
.BR PR_GET_FPEXC " (since Linux 2.4.21, 2.5.32, only on PowerPC)"
|
||||
Return floating-point exception mode,
|
||||
in the location pointed to by
|
||||
.IR "(int\ *) arg2" .
|
||||
.\" prctl PR_SET_KEEPCAPS
|
||||
.TP
|
||||
.BR PR_SET_KEEPCAPS " (since Linux 2.2.18)"
|
||||
Set the state of the calling thread's "keep capabilities" flag.
|
||||
|
@ -485,6 +501,7 @@ must be either 0 (clear the flag)
|
|||
or 1 (set the flag).
|
||||
The "keep capabilities" value will be reset to 0 on subsequent calls to
|
||||
.BR execve (2).
|
||||
.\" prctl PR_GET_KEEPCAPS
|
||||
.TP
|
||||
.BR PR_GET_KEEPCAPS " (since Linux 2.2.18)"
|
||||
Return (as the function result) the current state of the calling thread's
|
||||
|
@ -492,6 +509,7 @@ Return (as the function result) the current state of the calling thread's
|
|||
See
|
||||
.BR capabilities (7)
|
||||
for a description of this flag.
|
||||
.\" prctl PR_MCE_KILL
|
||||
.TP
|
||||
.BR PR_MCE_KILL " (since Linux 2.6.32)"
|
||||
Set the machine check memory corruption kill policy for the calling thread.
|
||||
|
@ -532,6 +550,7 @@ The policy is inherited by children.
|
|||
The remaining unused
|
||||
.BR prctl ()
|
||||
arguments must be zero for future compatibility.
|
||||
.\" prctl PR_MCE_KILL_GET
|
||||
.TP
|
||||
.BR PR_MCE_KILL_GET " (since Linux 2.6.32)"
|
||||
Return (as the function result)
|
||||
|
@ -539,6 +558,7 @@ the current per-process machine check kill policy.
|
|||
All unused
|
||||
.BR prctl ()
|
||||
arguments must be zero.
|
||||
.\" prctl PR_SET_MM
|
||||
.TP
|
||||
.BR PR_SET_MM " (since Linux 3.3)"
|
||||
.\" commit 028ee4be34a09a6d48bdf30ab991ae933a7bc036
|
||||
|
@ -716,6 +736,7 @@ This feature is available only if the kernel is built with the
|
|||
.BR CONFIG_CHECKPOINT_RESTORE
|
||||
option enabled.
|
||||
.RE
|
||||
.\" prctl PR_MPX_ENABLE_MANAGEMENT
|
||||
.TP
|
||||
.BR PR_MPX_ENABLE_MANAGEMENT ", " PR_MPX_DISABLE_MANAGEMENT " (since Linux 3.19) "
|
||||
.\" commit fe3d197f84319d3bce379a9c0dc17b1f48ad358c
|
||||
|
@ -791,6 +812,7 @@ had been called.
|
|||
.IP
|
||||
For further information on Intel MPX, see the kernel source file
|
||||
.IR Documentation/x86/intel_mpx.txt .
|
||||
.\" prctl PR_SET_NAME
|
||||
.TP
|
||||
.BR PR_SET_NAME " (since Linux 2.6.9)"
|
||||
Set the name of the calling thread,
|
||||
|
@ -819,6 +841,7 @@ in the buffer pointed to by
|
|||
.IR "(char\ *) arg2" .
|
||||
The buffer should allow space for up to 16 bytes;
|
||||
the returned string will be null-terminated.
|
||||
.\" prctl PR_SET_NO_NEW_PRIVS
|
||||
.TP
|
||||
.BR PR_SET_NO_NEW_PRIVS " (since Linux 3.5)"
|
||||
Set the calling thread's
|
||||
|
@ -862,6 +885,7 @@ For more information, see the kernel source file
|
|||
before Linux 4.13).
|
||||
See also
|
||||
.BR seccomp (2).
|
||||
.\" prctl PR_GET_NO_NEW_PRIVS
|
||||
.TP
|
||||
.BR PR_GET_NO_NEW_PRIVS " (since Linux 3.5)"
|
||||
Return (as the function result) the value of the
|
||||
|
@ -873,6 +897,7 @@ behavior.
|
|||
A value of 1 indicates
|
||||
.BR execve (2)
|
||||
will operate in the privilege-restricting mode described above.
|
||||
.\" prctl PR_SET_PDEATHSIG
|
||||
.TP
|
||||
.BR PR_SET_PDEATHSIG " (since Linux 2.1.57)"
|
||||
Set the parent-death signal
|
||||
|
@ -922,11 +947,13 @@ or a binary that has associated capabilities (see
|
|||
.BR capabilities (7));
|
||||
otherwise, this value is preserved across
|
||||
.BR execve (2).
|
||||
.\" prctl PR_GET_PDEATHSIG
|
||||
.TP
|
||||
.BR PR_GET_PDEATHSIG " (since Linux 2.3.15)"
|
||||
Return the current value of the parent process death signal,
|
||||
in the location pointed to by
|
||||
.IR "(int\ *) arg2" .
|
||||
.\" prctl PR_SET_PTRACER
|
||||
.TP
|
||||
.BR PR_SET_PTRACER " (since Linux 3.4)"
|
||||
.\" commit 2d514487faf188938a4ee4fb3464eeecfbdcf8eb
|
||||
|
@ -959,6 +986,7 @@ For further information, see the kernel source file
|
|||
(or
|
||||
.IR Documentation/security/Yama.txt
|
||||
before Linux 4.13).
|
||||
.\" prctl PR_SET_SECCOMP
|
||||
.TP
|
||||
.BR PR_SET_SECCOMP " (since Linux 2.6.23)"
|
||||
.\" See http://thread.gmane.org/gmane.linux.kernel/542632
|
||||
|
@ -1035,6 +1063,7 @@ For further information, see the kernel source file
|
|||
(or
|
||||
.IR Documentation/prctl/seccomp_filter.txt
|
||||
before Linux 4.13).
|
||||
.\" prctl PR_GET_SECCOMP
|
||||
.TP
|
||||
.BR PR_GET_SECCOMP " (since Linux 2.6.23)"
|
||||
Return (as the function result)
|
||||
|
@ -1061,18 +1090,21 @@ field of the
|
|||
file provides a method of obtaining the same information,
|
||||
without the risk that the process is killed; see
|
||||
.BR proc (5).
|
||||
.\" prctl PR_SET_SECUREBITS
|
||||
.TP
|
||||
.BR PR_SET_SECUREBITS " (since Linux 2.6.26)"
|
||||
Set the "securebits" flags of the calling thread to the value supplied in
|
||||
.IR arg2 .
|
||||
See
|
||||
.BR capabilities (7).
|
||||
.\" prctl PR_GET_SECUREBITS
|
||||
.TP
|
||||
.BR PR_GET_SECUREBITS " (since Linux 2.6.26)"
|
||||
Return (as the function result)
|
||||
the "securebits" flags of the calling thread.
|
||||
See
|
||||
.BR capabilities (7).
|
||||
.\" prctl PR_GET_SPECULATION_CTRL
|
||||
.TP
|
||||
.BR PR_GET_SPECULATION_CTRL " (since Linux 4.17)"
|
||||
Return (as the function result)
|
||||
|
@ -1119,6 +1151,7 @@ and
|
|||
.I arg5
|
||||
arguments must be specified as 0; otherwise the call fails with the error
|
||||
.BR EINVAL .
|
||||
.\" prctl PR_SET_SPECULATION_CTRL
|
||||
.TP
|
||||
.BR PR_SET_SPECULATION_CTRL " (since Linux 4.17)"
|
||||
.\" commit b617cfc858161140d69cc0b5cc211996b557a1c7
|
||||
|
@ -1174,6 +1207,7 @@ call failing with the error
|
|||
.BR ENXIO .
|
||||
For further details, see the kernel source file
|
||||
.IR Documentation/admin-guide/kernel-parameters.txt .
|
||||
.\" prctl PR_SET_THP_DISABLE
|
||||
.TP
|
||||
.BR PR_SET_THP_DISABLE " (since Linux 3.15)"
|
||||
.\" commit a0715cc22601e8830ace98366c0c2bd8da52af52
|
||||
|
@ -1191,6 +1225,7 @@ The setting of the "THP disable" flag is inherited by a child created via
|
|||
and is preserved across
|
||||
.BR execve (2).
|
||||
.\"
|
||||
.\" prctl PR_TASK_PERF_EVENTS_DISABLE
|
||||
.TP
|
||||
.BR PR_TASK_PERF_EVENTS_DISABLE " (since Linux 2.6.31)"
|
||||
Disable all performance counters attached to the calling process,
|
||||
|
@ -1207,6 +1242,7 @@ Originally called
|
|||
renamed (retaining the same numerical value)
|
||||
in Linux 2.6.32.
|
||||
.\"
|
||||
.\" prctl PR_TASK_PERF_EVENTS_ENABLE
|
||||
.TP
|
||||
.BR PR_TASK_PERF_EVENTS_ENABLE " (since Linux 2.6.31)"
|
||||
The converse of
|
||||
|
@ -1220,11 +1256,13 @@ renamed
|
|||
.\" commit cdd6c482c9ff9c55475ee7392ec8f672eddb7be6
|
||||
in Linux 2.6.32.
|
||||
.\"
|
||||
.\" prctl PR_GET_THP_DISABLE
|
||||
.TP
|
||||
.BR PR_GET_THP_DISABLE " (since Linux 3.15)"
|
||||
Return (as the function result) the current setting of the "THP disable"
|
||||
flag for the calling thread:
|
||||
either 1, if the flag is set, or 0, if it is not.
|
||||
.\" prctl PR_GET_TID_ADDRESS
|
||||
.TP
|
||||
.BR PR_GET_TID_ADDRESS " (since Linux 3.5)"
|
||||
.\" commit 300f786b2683f8bb1ec0afb6e1851183a479c86d
|
||||
|
@ -1246,6 +1284,7 @@ system call does not have a compat implementation for
|
|||
the AMD64 x32 and MIPS n32 ABIs,
|
||||
and the kernel writes out a pointer using the kernel's pointer size,
|
||||
this operation expects a user-space buffer of 8 (not 4) bytes on these ABIs.
|
||||
.\" prctl PR_SET_TIMERSLACK
|
||||
.TP
|
||||
.BR PR_SET_TIMERSLACK " (since Linux 2.6.28)"
|
||||
.\" See https://lwn.net/Articles/369549/
|
||||
|
@ -1316,10 +1355,12 @@ can be examined and changed via the file
|
|||
.IR /proc/[pid]/timerslack_ns .
|
||||
See
|
||||
.BR proc (5).
|
||||
.\" prctl PR_GET_TIMERSLACK
|
||||
.TP
|
||||
.BR PR_GET_TIMERSLACK " (since Linux 2.6.28)"
|
||||
Return (as the function result)
|
||||
the "current" timer slack value of the calling thread.
|
||||
.\" prctl PR_SET_TIMING
|
||||
.TP
|
||||
.BR PR_SET_TIMING " (since Linux 2.6.0)"
|
||||
.\" Precisely: Linux 2.6.0-test4
|
||||
|
@ -1338,11 +1379,13 @@ is not currently implemented
|
|||
.\" PR_TIMING_TIMESTAMP doesn't do anything in 2.6.26-rc8,
|
||||
.\" and looking at the patch history, it appears
|
||||
.\" that it never did anything.
|
||||
.\" prctl PR_GET_TIMING
|
||||
.TP
|
||||
.BR PR_GET_TIMING " (since Linux 2.6.0)"
|
||||
.\" Precisely: Linux 2.6.0-test4
|
||||
Return (as the function result) which process timing method is currently
|
||||
in use.
|
||||
.\" prctl PR_SET_TSC
|
||||
.TP
|
||||
.BR PR_SET_TSC " (since Linux 2.6.26, x86 only)"
|
||||
Set the state of the flag determining whether the timestamp counter
|
||||
|
@ -1356,12 +1399,14 @@ to allow it to be read, or
|
|||
to generate a
|
||||
.B SIGSEGV
|
||||
when the process tries to read the timestamp counter.
|
||||
.\" prctl PR_GET_TSC
|
||||
.TP
|
||||
.BR PR_GET_TSC " (since Linux 2.6.26, x86 only)"
|
||||
Return the state of the flag determining whether the timestamp counter
|
||||
can be read,
|
||||
in the location pointed to by
|
||||
.IR "(int\ *) arg2" .
|
||||
.\" prctl PR_SET_UNALIGN
|
||||
.TP
|
||||
.B PR_SET_UNALIGN
|
||||
(Only on: ia64, since Linux 2.3.48; parisc, since Linux 2.6.15;
|
||||
|
@ -1385,6 +1430,7 @@ flag in
|
|||
operation of the
|
||||
.BR setsysinfo ()
|
||||
system call on Tru64).
|
||||
.\" prctl PR_GET_UNALIGN
|
||||
.TP
|
||||
.B PR_GET_UNALIGN
|
||||
(See
|
||||
|
@ -1392,6 +1438,7 @@ system call on Tru64).
|
|||
for information on versions and architectures.)
|
||||
Return unaligned access control bits, in the location pointed to by
|
||||
.IR "(unsigned int\ *) arg2" .
|
||||
.\" prctl PR_SET_IO_FLUSHER
|
||||
.TP
|
||||
.BR PR_SET_IO_FLUSHER " (since Linux 5.6)"
|
||||
If a user process is involved in the block layer or filesystem I/O path,
|
||||
|
@ -1420,6 +1467,7 @@ and is preserved across
|
|||
Examples of IO_FLUSHER applications are FUSE daemons, SCSI device
|
||||
emulation daemons, and daemons that perform error handling like multipath
|
||||
path recovery applications.
|
||||
.\" prctl PR_GET_IO_FLUSHER
|
||||
.TP
|
||||
.B PR_GET_IO_FLUSHER (Since Linux 5.6)
|
||||
Return (as the function result) the IO_FLUSHER state of the caller.
|
||||
|
|
Loading…
Reference in New Issue