prctl.2: Document (uncomment) PR_SET_MM options in Linux 3.5

Some of the PR_SET_MM options were merged to vanilla kernel
later, and appeared in Linux 3.5. Those are:

   - PR_SET_MM_ARG_START
   - PR_SET_MM_ARG_END
   - PR_SET_MM_ENV_START
   - PR_SET_MM_ENV_END
   - PR_SET_MM_AUXV
   - PR_SET_MM_EXE_FILE

This patch merely uncomments description and error codes
for these options, which were present but commented out,
and removes the appropriate FIXME marks.

Signed-off-by: Kir Kolyshkin <kir@openvz.org>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>

man2/prctl.2

@@ -713,67 +713,64 @@ value.
 The requirements for the address are the same as for the
 .BR PR_SET_MM_START_BRK
 option.
-.\" FIXME The following (until ========) is not yet in mainline kernel,
+.TP
-.\" so commented out for the moment.
+.BR PR_SET_MM_ARG_START
-.\" .TP
+Set the address above which the program command line is placed.
-.\" .BR PR_SET_MM_ARG_START
+.TP
-.\" Set the address above which the program command line is placed.
+.BR PR_SET_MM_ARG_END
-.\" .TP
+Set the address below which the program command line is placed.
-.\" .BR PR_SET_MM_ARG_END
+.TP
-.\" Set the address below which the program command line is placed.
+.BR PR_SET_MM_ENV_START
-.\" .TP
+Set the address above which the program environment is placed.
-.\" .BR PR_SET_MM_ENV_START
+.TP
-.\" Set the address above which the program environment is placed.
+.BR PR_SET_MM_ENV_END
-.\" .TP
+Set the address below which the program environment is placed.
-.\" .BR PR_SET_MM_ENV_END
+.IP
-.\" Set the address below which the program environment is placed.
+The address passed with
-.\" .IP
+.BR PR_SET_MM_ARG_START ,
-.\" The address passed with
+.BR PR_SET_MM_ARG_END ,
-.\" .BR PR_SET_MM_ARG_START ,
+.BR PR_SET_MM_ENV_START ,
-.\" .BR PR_SET_MM_ARG_END ,
+and
-.\" .BR PR_SET_MM_ENV_START ,
+.BR PR_SET_MM_ENV_END
-.\" and
+should belong to a process stack area.
-.\" .BR PR_SET_MM_ENV_END
+Thus, the corresponding memory area must be readable, writable, and
-.\" should belong to a process stack area.
+(depending on the kernel configuration) have the
-.\" Thus, the corresponding memory area must be readable, writable, and
+.BR MAP_GROWSDOWN
-.\" (depending on the kernel configuration) have the
+attribute set (see
-.\" .BR MAP_GROWSDOWN
+.BR mmap (2)).
-.\" attribute set (see
+.TP
-.\" .BR mmap (2)).
+.BR PR_SET_MM_AUXV
-.\" .TP
+Set a new auxiliary vector.
-.\" .BR PR_SET_MM_AUXV
+The
-.\" Set a new auxiliary vector.
+.I arg3
-.\" The
+argument should provide the address of the vector.
-.\" .I arg3
+The
-.\" argument should provide the address of the vector.
+.I arg4
-.\" The
+is the size of the vector.
-.\" .I arg4
+.TP
-.\" is the size of the vector.
+.BR PR_SET_MM_EXE_FILE
-.\" .TP
+Supersede the
-.\" .BR PR_SET_MM_EXE_FILE
+.IR /proc/pid/exe
-.\" Supersede the
+symbolic link with a new one pointing to a new executable file
-.\" .IR /proc/pid/exe
+identified by the file descriptor provided in
-.\" symbolic link with a new one pointing to a new executable file
+.I arg3
-.\" identified by the file descriptor provided in
+argument.
-.\" .I arg3
+The file descriptor should be obtained with a regular
-.\" argument.
+.BR open (2)
-.\" The file descriptor should be obtained with a regular
+call.
-.\" .BR open (2)
+.IP
-.\" call.
+To change the symbolic link, one needs to unmap all existing
-.\" .IP
+executable memory areas, including those created by the kernel itself
-.\" To change the symbolic link, one needs to unmap all existing
+(for example the kernel usually creates at least one executable
-.\" executable memory areas, including those created by the kernel itself
+memory area for the ELF
-.\" (for example the kernel usually creates at least one executable
+.IR \.text
-.\" memory area for the ELF
+section).
-.\" .IR \.text
+.IP
-.\" section).
+The second limitation is that such transitions can be done only once
-.\" .IP
+in a process life time.
-.\" The second limitation is that such transitions can be done only once
+Any further attempts will be rejected.
-.\" in a process life time.
+This should help system administrators to monitor unusual
-.\" Any further attempts will be rejected.
+symbolic-link transitions over all process running in a system.
-.\" This should help system administrators to monitor unusual
-.\" symbolic-link transitions over all process running in a system.
-.\" ========== END FIXME
 .RE
 .\"
 .SH RETURN VALUE
@@ -919,41 +916,38 @@ is
 and the caller does not have the
 .B CAP_SYS_RESOURCE
 capability.
-.\" FIXME The following (until ========) is not yet in mainline kernel,
+.TP
-.\" so commented out for the moment.
+.B EACCES
-.\" .TP
+.I option
-.\" .B EACCES
+is
-.\" .I option
+.BR PR_SET_MM ,
-.\" is
+and
-.\" .BR PR_SET_MM ,
+.I arg3
-.\" and
+is
-.\" .I arg3
+.BR PR_SET_MM_EXE_FILE ,
-.\" is
+the file is not executable.
-.\" .BR PR_SET_MM_EXE_FILE ,
+.TP
-.\" the file is not executable.
+.B EBUSY
-.\" .TP
+.I option
-.\" .B EBUSY
+is
-.\" .I option
+.BR PR_SET_MM ,
-.\" is
+.I arg3
-.\" .BR PR_SET_MM ,
+is
-.\" .I arg3
+.BR PR_SET_MM_EXE_FILE ,
-.\" is
+and this the second attempt to change the
-.\" .BR PR_SET_MM_EXE_FILE ,
+.I /proc/pid/exe
-.\" and this the second attempt to change the
+symbolic link, which is prohibited.
-.\" .I /proc/pid/exe
+.TP
-.\" symbolic link, which is prohibited.
+.B EBADF
-.\" .TP
+.I option
-.\" .B EBADF
+is
-.\" .I option
+.BR PR_SET_MM ,
-.\" is
+.I arg3
-.\" .BR PR_SET_MM ,
+is
-.\" .I arg3
+.BR PR_SET_MM_EXE_FILE ,
-.\" is
+and the file descriptor passed in
-.\" .BR PR_SET_MM_EXE_FILE ,
+.I arg4
-.\" and the file descriptor passed in
+is not valid.
-.\" .I arg4
-.\" is not valid.
-.\" ========== END FIXME
 .\" The following can't actually happen, because prctl() in
 .\" seccomp mode will cause SIGKILL.
 .\" .TP