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@xxxxxxx> --- man2/prctl.2 | 48 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 48 insertions(+) diff --git a/man2/prctl.2 b/man2/prctl.2 index 9736434..e5b2b4b 100644 --- a/man2/prctl.2 +++ b/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. -- 2.1.4
