Module Name: src
Committed By: uwe
Date: Sun Apr 28 23:10:26 UTC 2024
Modified Files:
src/lib/libc/sys: execve.2
Log Message:
execve(2): brush up markup
To generate a diff of this commit:
cvs rdiff -u -r1.46 -r1.47 src/lib/libc/sys/execve.2
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/lib/libc/sys/execve.2
diff -u src/lib/libc/sys/execve.2:1.46 src/lib/libc/sys/execve.2:1.47
--- src/lib/libc/sys/execve.2:1.46 Sun Apr 28 22:21:21 2024
+++ src/lib/libc/sys/execve.2 Sun Apr 28 23:10:26 2024
@@ -1,4 +1,4 @@
-.\" $NetBSD: execve.2,v 1.46 2024/04/28 22:21:21 rillig Exp $
+.\" $NetBSD: execve.2,v 1.47 2024/04/28 23:10:26 uwe Exp $
.\"
.\" Copyright (c) 1980, 1991, 1993
.\" The Regents of the University of California. All rights reserved.
@@ -75,35 +75,32 @@ and
.Xr a.out 5 .
.Pp
An interpreter file begins with a line of the form:
-.Pp
-.Bd -ragged -offset indent -compact
-.Sy \&#!
-.Em interpreter
-.Bq Em arg
+.Bd -ragged -offset indent
+.Ic \&#! Ns Ar interpreter Op Ar arg
.Ed
.Pp
When an interpreter file is
-.Sy execve Ap d ,
+.Nm Ap d ,
the system actually
-.Sy execve Ap s
+.Nm Ap s
the specified
-.Em interpreter .
+.Ar interpreter .
If the optional
-.Em arg
+.Ar arg
is specified, it becomes the first argument to the
-.Em interpreter ,
+.Ar interpreter ,
and the name of the originally
-.Sy execve Ap d
+.Nm Ap d
file becomes the second argument;
otherwise, the name of the originally
-.Sy execve Ap d
+.Nm Ap d
file becomes the first argument.
The original arguments are shifted over to become the subsequent arguments.
The zeroth argument, normally the name of the
-.Fn execve Ns d
+.Nm Ap d
file, is left unchanged.
The interpreter named by
-.Em interpreter
+.Ar interpreter
must not itself be an interpreter file.
(See
.Xr script 7
@@ -127,8 +124,8 @@ character pointers to null-terminated st
A pointer to this array is normally stored in the global variable
.Va environ .
These strings pass information to the
-new process that is not directly an argument to the command (see
-.Xr environ 7 ) .
+new process that is not directly an argument to the command
+.Pq see Xr environ 7 .
.Pp
File descriptors open in the calling process image remain open in
the new process image, except for those for which the close-on-exec
@@ -140,12 +137,18 @@ Descriptors that remain open are unaffec
.Fn execve .
.Pp
In the case of a new setuid or setgid executable being executed, if
-file descriptors 0, 1, or 2 (representing stdin, stdout, and stderr)
+file descriptors 0, 1, or 2
+.Po
+representing
+.Em stdin , stdout ,
+and
+.Em stderr
+.Pc
are currently unallocated, these descriptors will be opened to point to
some system file like
.Pa /dev/null .
The intent is to ensure these descriptors are not unallocated, since
-many libraries make assumptions about the use of these 3 file descriptors.
+many libraries make assumptions about the use of these three file descriptors.
.Pp
Signals set to be ignored in the calling process are set to be ignored in
the new process.
@@ -157,8 +160,7 @@ The signal stack is reset to be undefine
for more information).
.Pp
If the set-user-ID mode bit of the new process image file is set
-(see
-.Xr chmod 2 ) ,
+.Pq see Xr chmod 2 ,
the effective user ID of the new process image is set to the owner ID
of the new process image file.
If the set-group-ID mode bit of the new process image file is set,
@@ -171,8 +173,8 @@ process image.
After any set-user-ID and set-group-ID processing,
the effective user ID is recorded as the saved set-user-ID,
and the effective group ID is recorded as the saved set-group-ID.
-These values may be used in changing the effective IDs later (see
-.Xr setuid 2 ) .
+These values may be used in changing the effective IDs later
+.Pq see Xr setuid 2 .
The set-ID bits are not honored if the respective file system has the
.Cm nosuid
option enabled or if the new process file is an interpreter file.
@@ -182,20 +184,19 @@ tracing is disabled if effective IDs are
The new process also inherits the following attributes from
the calling process:
.Pp
-.Bl -column parent_process_ID -offset indent -compact
-.It process ID Ta see Xr getpid 2
+.Bl -column "parent process ID" -offset indent -compact
+.It process ID Ta see Xr getpid 2
.It parent process ID Ta see Xr getppid 2
-.It process group ID Ta see Xr getpgrp 2
-.It access groups Ta see Xr getgroups 2
+.It process group ID Ta see Xr getpgrp 2
+.It access groups Ta see Xr getgroups 2
.It working directory Ta see Xr chdir 2
-.It root directory Ta see Xr chroot 2
-.It control terminal Ta see Xr termios 4
-.It resource usages Ta see Xr getrusage 2
-.It interval timers Ta see Xr getitimer 2
-.It resource limits Ta see Xr getrlimit 2
-.It file mode mask Ta see Xr umask 2
-.It signal mask Ta see Xr sigaction 2 ,
-.Xr sigprocmask 2
+.It root directory Ta see Xr chroot 2
+.It control terminal Ta see Xr termios 4
+.It resource usages Ta see Xr getrusage 2
+.It interval timers Ta see Xr getitimer 2
+.It resource limits Ta see Xr getrlimit 2
+.It file mode mask Ta see Xr umask 2
+.It signal mask Ta see Xr sigaction 2 , Xr sigprocmask 2
.El
.Pp
When a program is executed as a result of an
@@ -209,10 +210,9 @@ char **argv, **envp;
.Pp
where
.Fa argc
+.Pq the Dq arg count
is the number of elements in
-.Fa argv
-(the
-.Dq arg count )
+.Fa argv ,
and
.Fa argv
points to the array of character pointers
@@ -264,7 +264,7 @@ The default compile time limit is 262144
in the variable
.Dv NCARGS
in
-.Aq Pa sys/param.h
+.In sys/param.h
and get be read from the
.Xr sysctl 3
MIB variable
@@ -275,9 +275,11 @@ the new process file is not an ordinary
its file mode denies execute permission, or
it is on a file system mounted with execution
disabled
-.Dv ( MNT_NOEXEC
+.Po
+.Dv MNT_NOEXEC
in
-.Ao Pa sys/mount.h Ac ) .
+.In sys/mount.h
+.Pc .
.It Bq Er EAGAIN
A
.Xr setuid 7
@@ -305,7 +307,7 @@ characters.
.It Bq Er ENOENT
The new process file does not exist, or
the new process file is a script starting with
-.Li #!
+.Ql #!
and the script interpreter does not exist.
.It Bq Er ENOEXEC
The new process file has the appropriate access
