update from Mike Karels at BSDI

SCCS-vsn: lib/libc/sys/execve.2 6.10
SCCS-vsn: lib/libc/sys/setuid.2 6.7
SCCS-vsn: lib/libc/sys/sigaction.2 6.6

diff --git a/usr/src/lib/libc/sys/execve.2 b/usr/src/lib/libc/sys/execve.2
index 1ba96f9..d6a1966 100644 (file)
--- a/usr/src/lib/libc/sys/execve.2
+++ b/usr/src/lib/libc/sys/execve.2
@@ -3,7 +3,7 @@
 .\"
 .\" %sccs.include.redist.man%
 .\"
 .\"
 .\" %sccs.include.redist.man%
 .\"

-.\"     @(#)execve.2   6.9 (Berkeley) %G%
+.\"     @(#)execve.2   6.10 (Berkeley) %G%

 .\"
 .Dd 
 .Dt EXECVE 2
 .\"
 .Dd 
 .Dt EXECVE 2


@@ -105,9 +105,15 @@ of the new process image file.
 If the set-group-ID mode bit of the new process image file is set,
 the effective group ID of the new process image is set to the group ID
 of the new process image file.
 If the set-group-ID mode bit of the new process image file is set,
 the effective group ID of the new process image is set to the group ID
 of the new process image file.

+(The effective group ID is the first element of the group list.)

 The real user ID, real group ID and
 The real user ID, real group ID and

-supplementary group IDs of the new process image remain the same as the calling
+other group IDs of the new process image remain the same as the calling

 process image.
 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 ) .

 .Pp
 The new process also inherits the following attributes from
 the calling process:
 .Pp
 The new process also inherits the following attributes from
 the calling process:

diff --git a/usr/src/lib/libc/sys/setuid.2 b/usr/src/lib/libc/sys/setuid.2
index 50ab101..24c748a 100644 (file)
--- a/usr/src/lib/libc/sys/setuid.2
+++ b/usr/src/lib/libc/sys/setuid.2
@@ -3,7 +3,7 @@
 .\"
 .\" %sccs.include.redist.man%
 .\"
 .\"
 .\" %sccs.include.redist.man%
 .\"

-.\"     @(#)setuid.2   6.6 (Berkeley) %G%
+.\"     @(#)setuid.2   6.7 (Berkeley) %G%

 .\"
 .Dd 
 .Dt SETUID 2
 .\"
 .Dd 
 .Dt SETUID 2


@@ -29,10 +29,24 @@
 The
 .Fn setuid
 function
 The
 .Fn setuid
 function

-.Pq Fn setgid
-sets both the real and effective
-user ID (group ID) of the current process
-as specified.
+sets the real and effective
+user IDs and the saved set-user-ID of the current process
+to the specified value.
+The
+.Fn setuid
+function is permitted if the specified ID is equal to the real user ID
+of the process, or if the effective user ID is that of the super user.
+.Pp
+The
+.Fn setgid
+function
+sets the real and effective
+group IDs and the saved set-group-ID of the current process
+to the specified value.
+The
+.Fn setgid
+function is permitted if the specified ID is equal to the real group ID
+of the process, or if the effective user ID is that of the super user.

 .Pp
 The
 .Fn seteuid
 .Pp
 The
 .Fn seteuid


@@ -40,6 +54,16 @@ function
 .Pq Fn setegid
 sets the effective user ID (group ID) of the
 current process.
 .Pq Fn setegid
 sets the effective user ID (group ID) of the
 current process.

+The effective user ID may be set to the value
+of the real user ID or the saved set-user-ID (see
+.Xr intro 2
+and
+.Xr execve 2 ) ;
+in this way, the effective user ID of a set-user-ID executable
+may be toggled by switching to the real user ID, then re-enabled
+by reverting to the set-user-ID value.
+Similarly, the effective group ID may be set to the value
+of the real group ID or the saved set-user-ID.

 .Pp
 .Sh RETURN VALUES
 Upon success, these functions return 0;
 .Pp
 .Sh RETURN VALUES
 Upon success, these functions return 0;


@@ -51,10 +75,22 @@ these functions return \-1.
 .Sh SEE ALSO
 .Xr getuid 2 ,
 .Xr getgid 2
 .Sh SEE ALSO
 .Xr getuid 2 ,
 .Xr getgid 2

-.Sh HISTORY
-A
+.Sh STANDARDS
+The

 .Fn setuid
 and
 .Fn setgid
 .Fn setuid
 and
 .Fn setgid

-syscall appeared in 
-.At v6 .
+functions are compliant with the
+.St -p1003.1-88
+specification with
+.Li _POSIX_SAVED_IDS
+not defined.
+The
+.Fn seteuid
+and
+.Fn setegid
+functions are extensions based on the 
+.Tn POSIX
+concept of
+.Li _POSIX_SAVED_IDS ,
+and have been proposed for a future revision of the standard.

diff --git a/usr/src/lib/libc/sys/sigaction.2 b/usr/src/lib/libc/sys/sigaction.2
index d0dfd34..69d5d1e 100644 (file)
--- a/usr/src/lib/libc/sys/sigaction.2
+++ b/usr/src/lib/libc/sys/sigaction.2
@@ -3,7 +3,7 @@
 .\"
 .\" %sccs.include.redist.roff%
 .\"
 .\"
 .\" %sccs.include.redist.roff%
 .\"

-.\"    @(#)sigaction.2 6.5 (Berkeley) %G%
+.\"    @(#)sigaction.2 6.6 (Berkeley) %G%

 .\"
 .Dd 
 .Dt SIGACTION 2
 .\"
 .Dd 
 .Dt SIGACTION 2


@@ -23,7 +23,7 @@ struct sigaction {
 .Fn sigaction "int sig" "struct sigaction *act" "struct sigaction *oact"
 .Sh DESCRIPTION
 The system defines a set of signals that may be delivered to a process.
 .Fn sigaction "int sig" "struct sigaction *act" "struct sigaction *oact"
 .Sh DESCRIPTION
 The system defines a set of signals that may be delivered to a process.

-Signal delivery resembles the occurence of a hardware interrupt:
+Signal delivery resembles the occurrence of a hardware interrupt:

 the signal is blocked from further occurrence, the current process 
 context is saved, and a new one is built.  A process may specify a
 .Em handler
 the signal is blocked from further occurrence, the current process 
 context is saved, and a new one is built.  A process may specify a
 .Em handler


@@ -122,6 +122,13 @@ See the signal list below for each signal's default action.
 If
 .Fa sa_handler
 is
 If
 .Fa sa_handler
 is

+.Dv SIG_DFL ,
+the default action for the signal is to discard the signal,
+and if a signal is pending,
+the pending signal is discarded even if the signal is masked.
+If
+.Fa sa_handler
+is set to

 .Dv SIG_IGN
 current and pending instances
 of the signal are ignored and discarded.
 .Dv SIG_IGN
 current and pending instances
 of the signal are ignored and discarded.


@@ -145,12 +152,13 @@ bit is set in
 the system will deliver the signal to the process on a
 .Em "signal stack" ,
 specified with
 the system will deliver the signal to the process on a
 .Em "signal stack" ,
 specified with

-.Xr sigaltstack 2 .
+.Xr sigstack 2 .

 .Pp
 If a signal is caught during the system calls listed below,
 the call may be forced to terminate
 with the error
 .Dv EINTR ,
 .Pp
 If a signal is caught during the system calls listed below,
 the call may be forced to terminate
 with the error
 .Dv EINTR ,

+the call may return with a data transfer shorter than requested,

 or the call may be restarted.
 Restart of pending calls is requested
 by setting the
 or the call may be restarted.
 Restart of pending calls is requested
 by setting the


@@ -158,6 +166,7 @@ by setting the
 bit in
 .Ar sa_flags .
 The affected system calls include
 bit in
 .Ar sa_flags .
 The affected system calls include

+.Xr open 2 ,

 .Xr read 2 ,
 .Xr write 2 ,
 .Xr sendto 2 ,
 .Xr read 2 ,
 .Xr write 2 ,
 .Xr sendto 2 ,


@@ -240,34 +249,56 @@ The mask specified in
 is not allowed to block
 .Dv SIGKILL
 or
 is not allowed to block
 .Dv SIGKILL
 or

-.Dv SIGSTOP
+.Dv SIGSTOP .

 This is done silently by the system.
 .Sh RETURN VALUES
 A 0 value indicated that the call succeeded.  A \-1 return value
 indicates an error occurred and
 .Va errno
 is set to indicated the reason.
 This is done silently by the system.
 .Sh RETURN VALUES
 A 0 value indicated that the call succeeded.  A \-1 return value
 indicates an error occurred and
 .Va errno
 is set to indicated the reason.

-.Sh ERROR
+.Sh EXAMPLE
+The handler routine can be declared:
+.Bd -literal -offset indent
+void handler(sig, code, scp)
+int sig, code;
+struct sigcontext *scp;
+.Ed
+.Pp
+Here
+.Fa sig
+is the signal number, into which the hardware faults and traps are
+mapped.
+.Em Code
+is a parameter that is either a constant
+or the code provided by
+the hardware.
+.Fa Scp
+is a pointer to the
+.Fa sigcontext
+structure (defined in
+.Aq Pa signal.h ) ,
+used to restore the context from before the signal.
+.Sh ERRORS

 .Fn Sigaction
 will fail and no new signal handler will be installed if one
 of the following occurs:
 .Fn Sigaction
 will fail and no new signal handler will be installed if one
 of the following occurs:

-.Tw Er
-.Tl Bq Er EFAULT
+.Bl -tag -width Er
+.It Bq Er EFAULT

 Either
 .Fa act
 or 
 .Fa oact
 points to memory that is not a valid part of the process
 address space.
 Either
 .Fa act
 or 
 .Fa oact
 points to memory that is not a valid part of the process
 address space.

-.Tl Bq Er EINVAL
+.It Bq Er EINVAL

 .Fa Sig
 is not a valid signal number.
 .Fa Sig
 is not a valid signal number.

-.Tl Bq Er EINVAL
+.It Bq Er EINVAL

 An attempt is made to ignore or supply a handler for
 An attempt is made to ignore or supply a handler for

-.Em SIGKIL
+.Em SIGKILL

 or
 .Dv SIGSTOP
 or
 .Dv SIGSTOP

-.Tl
+.El

 .Sh STANDARD
 The
 .Nm sigaction
 .Sh STANDARD
 The
 .Nm sigaction


@@ -292,7 +323,7 @@ as are the signals,
 .Dv SIGWINCH ,
 and
 .Dv SIGINFO .
 .Dv SIGWINCH ,
 and
 .Dv SIGINFO .

-Most of those signals are available on most
+Those signals are available on most

 .Tn BSD Ns \-derived
 systems.
 .Sh SEE ALSO
 .Tn BSD Ns \-derived
 systems.
 .Sh SEE ALSO


@@ -300,43 +331,14 @@ systems.
 .Xr ptrace 2 ,
 .Xr kill 2 ,
 .Xr sigaction 2 ,
 .Xr ptrace 2 ,
 .Xr kill 2 ,
 .Xr sigaction 2 ,

-.Xr sigaltstack 2 ,

 .Xr sigprocmask 2 ,
 .Xr sigprocmask 2 ,

-.Em sigsetops 2 ,
+.Xr sigsetops 2 ,

 .Xr sigsuspend 2 ,
 .Xr sigblock 2 ,
 .Xr sigsetmask 2 ,
 .Xr sigpause 2 ,
 .Xr sigsuspend 2 ,
 .Xr sigblock 2 ,
 .Xr sigsetmask 2 ,
 .Xr sigpause 2 ,

+.Xr sigstack 2 ,

 .Xr sigvec 2 ,
 .Xr setjmp 3 ,
 .Xr sigvec 2 ,
 .Xr setjmp 3 ,

-.Em siginterrupt 3 ,
+.Xr siginterrupt 3 ,

 .Xr tty 4
 .Xr tty 4

-.Sh EXAMPLE
-On a
-.Tn VAX\-11,
-the handler routine can be declared:
-.Bd -literal -offset indent
-void handler(sig, code, scp)
-int sig, code;
-struct sigcontext *scp;
-.Ed
-.Pp
-Here
-.Fa sig
-is the signal number, into which the hardware faults and traps are
-mapped as defined below. 
-.Em Code
-is a parameter that is either a constant
-as given below or the code provided by
-the hardware (Compatibility mode faults are distinguished from the
-other
-.Dv SIGILL
-traps by having
-.Dv PSL_CM
-set in the psl).
-.Fa Scp
-is a pointer to the
-.Fa sigcontext
-structure (defined in
-.Aq Pa signal.h ) ,
-used to restore the context from before the signal.