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authorcgd <cgd@NetBSD.org>1994-05-07 03:27:01 +0000
committercgd <cgd@NetBSD.org>1994-05-07 03:27:01 +0000
commitfc7bd30680b5458e98e6ffd7feea96ab00f228cf (patch)
tree7f02217dcc28df22155010e20962af0ae7697fa0 /lib/libc/sys
parent081527a86107a69561497f02e9902b1f0fee22fa (diff)
new syscalls
Diffstat (limited to 'lib/libc/sys')
-rw-r--r--lib/libc/sys/mlock.2161
-rw-r--r--lib/libc/sys/pathconf.2163
-rw-r--r--lib/libc/sys/sigaltstack.2165
3 files changed, 489 insertions, 0 deletions
diff --git a/lib/libc/sys/mlock.2 b/lib/libc/sys/mlock.2
new file mode 100644
index 00000000000..90bb7c7d8e0
--- /dev/null
+++ b/lib/libc/sys/mlock.2
@@ -0,0 +1,161 @@
+.\" Copyright (c) 1993
+.\" The Regents of the University of California. All rights reserved.
+.\"
+.\" Redistribution and use in source and binary forms, with or without
+.\" modification, are permitted provided that the following conditions
+.\" are met:
+.\" 1. Redistributions of source code must retain the above copyright
+.\" notice, this list of conditions and the following disclaimer.
+.\" 2. Redistributions in binary form must reproduce the above copyright
+.\" notice, this list of conditions and the following disclaimer in the
+.\" documentation and/or other materials provided with the distribution.
+.\" 3. All advertising materials mentioning features or use of this software
+.\" must display the following acknowledgement:
+.\" This product includes software developed by the University of
+.\" California, Berkeley and its contributors.
+.\" 4. Neither the name of the University nor the names of its contributors
+.\" may be used to endorse or promote products derived from this software
+.\" without specific prior written permission.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+.\" SUCH DAMAGE.
+.\"
+.\" @(#)mlock.2 8.2 (Berkeley) 12/11/93
+.\"
+.Dd June 2, 1993
+.Dt MLOCK 2
+.Os
+.Sh NAME
+.Nm mlock ,
+.Nm munlock
+.Nd lock (unlock) physical pages in memory
+.Sh SYNOPSIS
+.Fd #include <sys/types.h>
+.Fd #include <sys/mman.h>
+.Ft int
+.Fn mlock "caddr_t addr" "size_t len"
+.Ft int
+.Fn munlock "caddr_t addr" "size_t len"
+.Sh DESCRIPTION
+The
+.Nm mlock
+system call
+locks into memory the physical pages associated with the virtual address
+range starting at
+.Fa addr
+for
+.Fa len
+bytes.
+The
+.Nm munlock
+call unlocks pages previously locked by one or more
+.Nm mlock
+calls.
+For both, the
+.Fa addr
+parameter should be aligned to a multiple of the page size.
+If the
+.Fa len
+parameter is not a multiple of the page size, it will be rounded up
+to be so.
+The entire range must be allocated.
+.Pp
+After an
+.Nm mlock
+call, the indicated pages will cause neither a non-resident page
+nor address-translation fault until they are unlocked.
+They may still cause protection-violation faults or TLB-miss faults on
+architectures with software-managed TLBs.
+The physical pages remain in memory until all locked mappings for the pages
+are removed.
+Multiple processes may have the same physical pages locked via their own
+virtual address mappings.
+A single process may likewise have pages multiply-locked via different virtual
+mappings of the same pages or via nested
+.Nm mlock
+calls on the same address range.
+Unlocking is performed explicitly by
+.Nm munlock
+or implicitly by a call to
+.Nm munmap
+which deallocates the unmapped address range.
+Locked mappings are not inherited by the child process after a
+.Xr fork 2 .
+.Pp
+Since physical memory is a potentially scarce resource, processes are
+limited in how much they can lock down.
+A single process can
+.Nm mlock
+the minimum of
+a system-wide ``wired pages'' limit and
+the per-process
+.Li RLIMIT_MEMLOCK
+resource limit.
+.Sh RETURN VALUES
+A return value of 0 indicates that the call
+succeeded and all pages in the range have either been locked or unlocked.
+A return value of -1 indicates an error occurred and the locked
+status of all pages in the range remains unchanged.
+In this case, the global location
+.Va errno
+is set to indicate the error.
+.Sh ERRORS
+.Fn Mlock
+will fail if:
+.Bl -tag -width Er
+.It Bq Er EINVAL
+The address given is not page aligned or the length is negative.
+.It Bq Er EAGAIN
+Locking the indicated range would exceed either the system or per-process
+limit for locked memory.
+.It Bq Er ENOMEM
+Some portion of the indicated address range is not allocated.
+There was an error faulting/mapping a page.
+.El
+.Fn Munlock
+will fail if:
+.Bl -tag -width Er
+.It Bq Er EINVAL
+The address given is not page aligned or the length is negative.
+.It Bq Er ENOMEM
+Some portion of the indicated address range is not allocated.
+Some portion of the indicated address range is not locked.
+.El
+.Sh "SEE ALSO"
+.Xr fork 2 ,
+.Xr mmap 2 ,
+.Xr munmap 2 ,
+.Xr setrlimit 2 ,
+.Xr getpagesize 3
+.Sh BUGS
+Unlike The Sun implementation, multiple
+.Nm mlock
+calls on the same address range require the corresponding number of
+.Nm munlock
+calls to actually unlock the pages, i.e.
+.Nm mlock
+nests.
+This should be considered a consequence of the implementation
+and not a feature.
+.Pp
+The per-process resource limit is a limit on the amount of virtual
+memory locked, while the system-wide limit is for the number of locked
+physical pages.
+Hence a process with two distinct locked mappings of the same physical page
+counts as 2 pages against the per-process limit and as only a single page
+in the system limit.
+.Sh HISTORY
+The
+.Fn mlock
+and
+.Fn munlock
+functions first appeared in 4.4BSD.
diff --git a/lib/libc/sys/pathconf.2 b/lib/libc/sys/pathconf.2
new file mode 100644
index 00000000000..1b4fbc4362d
--- /dev/null
+++ b/lib/libc/sys/pathconf.2
@@ -0,0 +1,163 @@
+.\" Copyright (c) 1993
+.\" The Regents of the University of California. All rights reserved.
+.\"
+.\" Redistribution and use in source and binary forms, with or without
+.\" modification, are permitted provided that the following conditions
+.\" are met:
+.\" 1. Redistributions of source code must retain the above copyright
+.\" notice, this list of conditions and the following disclaimer.
+.\" 2. Redistributions in binary form must reproduce the above copyright
+.\" notice, this list of conditions and the following disclaimer in the
+.\" documentation and/or other materials provided with the distribution.
+.\" 3. All advertising materials mentioning features or use of this software
+.\" must display the following acknowledgement:
+.\" This product includes software developed by the University of
+.\" California, Berkeley and its contributors.
+.\" 4. Neither the name of the University nor the names of its contributors
+.\" may be used to endorse or promote products derived from this software
+.\" without specific prior written permission.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+.\" SUCH DAMAGE.
+.\"
+.\" @(#)pathconf.2 8.1 (Berkeley) 6/4/93
+.\"
+.Dd June 4, 1993
+.Dt PATHCONF 2
+.Os BSD 4
+.Sh NAME
+.Nm pathconf ,
+.Nm fpathconf
+.Nd get configurable pathname variables
+.Sh SYNOPSIS
+.Fd #include <unistd.h>
+.Ft long
+.Fn pathconf "const char *path" "int name"
+.Ft long
+.Fn fpathconf "int fd" "int name"
+.Sh DESCRIPTION
+.Pp
+The
+.Fn pathconf
+and
+.Fn fpathconf
+functions provides a method for applications to determine the current
+value of a configurable system limit or option variable associated
+with a pathname or file descriptor.
+.Pp
+For
+.Nm pathconf ,
+the
+.Fa path
+argument is the name of a file or directory.
+For
+.Nm fpathconf ,
+the
+.Fa fd
+argument is an open file descriptor.
+The
+.Fa name
+argument specifies the system variable to be queried.
+Symbolic constants for each name value are found in the include file
+.Li <unistd.h> .
+.Pp
+The available values are as follows:
+.Pp
+.Bl -tag -width "123456"
+.Pp
+.It Li _PC_LINK_MAX
+The maximum file link count.
+.It Li _PC_MAX_CANON
+The maximum number of bytes in terminal canonical input line.
+.It Li _PC_MAX_INPUT
+The minimum maximum number of bytes for which space is available in
+a terminal input queue.
+.It Li _PC_NAME_MAX
+The maximum number of bytes in a file name.
+.It Li _PC_PATH_MAX
+The maximum number of bytes in a pathname.
+.It Li _PC_PIPE_BUF
+The maximum number of bytes which will be written atomically to a pipe.
+.It Li _PC_CHOWN_RESTRICTED
+Return 1 if appropriate privileges are required for the
+.Xr chown 2
+system call, otherwise 0.
+.It Li _PC_NO_TRUNC
+Return 1 if file names longer than KERN_NAME_MAX are truncated.
+.It Li _PC_VDISABLE
+Returns the terminal character disabling value.
+.El
+.Sh RETURN VALUES
+If the call to
+.Nm pathconf
+or
+.Nm fpathconf
+is not successful, \-1 is returned and
+.Va errno
+is set appropriately.
+Otherwise, if the variable is associated with functionality that does
+not have a limit in the system, \-1 is returned and
+.Va errno
+is not modified.
+Otherwise, the current variable value is returned.
+.Sh ERRORS
+If any of the following conditions occur, the
+.Nm pathconf
+and
+.Nm fpathconf
+functions shall return -1 and set
+.Va errno
+to the corresponding value.
+.Bl -tag -width Er
+.It Bq Er EINVAL
+The value of the
+.Fa name
+argument is invalid.
+.It Bq Er EINVAL
+The implementation does not support an association of the variable
+name with the associated file.
+.El
+.Fn Pathconf
+will fail if:
+.Bl -tag -width ENAMETOOLONGAA
+.It Bq Er ENOTDIR
+A component of the path prefix is not a directory.
+.It Bq Er ENAMETOOLONG
+A component of a pathname exceeded 255 characters,
+or an entire path name exceeded 1023 characters.
+.It Bq Er ENOENT
+The named file does not exist.
+.It Bq Er EACCES
+Search permission is denied for a component of the path prefix.
+.It Bq Er ELOOP
+Too many symbolic links were encountered in translating the pathname.
+.It Bq Er EIO
+An I/O error occurred while reading from or writing to the file system.
+.El
+.Pp
+.Bl -tag -width [EFAULT]
+.Fn Fpathconf
+will fail if:
+.It Bq Er EBADF
+.Fa fd
+is not a valid open file descriptor.
+.It Bq Er EIO
+An I/O error occurred while reading from or writing to the file system.
+.El
+.Sh SEE ALSO
+.Xr sysctl 3
+.Sh HISTORY
+The
+.Nm pathconf
+and
+.Nm fpathconf
+functions first appeared in 4.4BSD.
diff --git a/lib/libc/sys/sigaltstack.2 b/lib/libc/sys/sigaltstack.2
new file mode 100644
index 00000000000..f1ed718eb96
--- /dev/null
+++ b/lib/libc/sys/sigaltstack.2
@@ -0,0 +1,165 @@
+.\" Copyright (c) 1983, 1991, 1992, 1993
+.\" The Regents of the University of California. All rights reserved.
+.\"
+.\" Redistribution and use in source and binary forms, with or without
+.\" modification, are permitted provided that the following conditions
+.\" are met:
+.\" 1. Redistributions of source code must retain the above copyright
+.\" notice, this list of conditions and the following disclaimer.
+.\" 2. Redistributions in binary form must reproduce the above copyright
+.\" notice, this list of conditions and the following disclaimer in the
+.\" documentation and/or other materials provided with the distribution.
+.\" 3. All advertising materials mentioning features or use of this software
+.\" must display the following acknowledgement:
+.\" This product includes software developed by the University of
+.\" California, Berkeley and its contributors.
+.\" 4. Neither the name of the University nor the names of its contributors
+.\" may be used to endorse or promote products derived from this software
+.\" without specific prior written permission.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+.\" SUCH DAMAGE.
+.\"
+.\" @(#)sigaltstack.2 8.1 (Berkeley) 6/4/93
+.\"
+.Dd June 4, 1993
+.Dt SIGALTSTACK 2
+.Os BSD 4.2
+.Sh NAME
+.Nm sigaltstack
+.Nd set and/or get signal stack context
+.Sh SYNOPSIS
+.Fd #include <sys/types.h>
+.Fd #include <signal.h>
+.Bd -literal
+struct sigaltstack {
+ caddr_t ss_sp;
+ long ss_size;
+ int ss_flags;
+};
+.Ed
+.Ft int
+.Fn sigaltstack "const struct sigaltstack *ss" "struct sigaltstack *oss"
+.Sh DESCRIPTION
+.Fn Sigaltstack
+allows users to define an alternate stack on which signals
+are to be processed.
+If
+.Fa ss
+is non-zero,
+it specifies a pointer to and the size of a
+.Em "signal stack"
+on which to deliver signals,
+and tells the system if the process is currently executing
+on that stack.
+When a signal's action indicates its handler
+should execute on the signal stack (specified with a
+.Xr sigaction 2
+call), the system checks to see
+if the process is currently executing on that stack.
+If the process is not currently executing on the signal stack,
+the system arranges a switch to the signal stack for the
+duration of the signal handler's execution.
+.Pp
+If
+.Dv SA_DISABLE
+is set in
+.Fa ss_flags ,
+.Fa ss_sp
+and
+.Fa ss_size
+are ignored and the signal stack will be disabled.
+Trying to disable an active stack will cause
+.Nm
+to return -1 with
+.Va errno
+set to
+.Dv EINVAL .
+A disabled stack will cause all signals to be
+taken on the regular user stack.
+If the stack is later re-enabled then all signals that were specified
+to be processed on an alternate stack will resume doing so.
+.Pp
+If
+.Fa oss
+is non-zero, the current signal stack state is returned.
+The
+.Fa ss_flags
+field will contain the value
+.Dv SA_ONSTACK
+if the process is currently on a signal stack and
+.Dv SA_DISABLE
+if the signal stack is currently disabled.
+.Sh NOTES
+The value
+.Dv SIGSTKSZ
+is defined to be the number of bytes/chars that would be used to cover
+the usual case when allocating an alternate stack area.
+The following code fragment is typically used to allocate an alternate stack.
+.Bd -literal -offset indent
+if ((sigstk.ss_sp = malloc(SIGSTKSZ)) == NULL)
+ /* error return */
+sigstk.ss_size = SIGSTKSZ;
+sigstk.ss_flags = 0;
+if (sigaltstack(&sigstk,0) < 0)
+ perror("sigaltstack");
+.Ed
+An alternative approach is provided for programs with signal handlers
+that require a specific amount of stack space other than the default size.
+The value
+.Dv MINSIGSTKSZ
+is defined to be the number of bytes/chars that is required by
+the operating system to implement the alternate stack feature.
+In computing an alternate stack size,
+programs should add
+.Dv MINSIGSTKSZ
+to their stack requirements to allow for the operating system overhead.
+.Pp
+Signal stacks are automatically adjusted for the direction of stack
+growth and alignment requirements.
+Signal stacks may or may not be protected by the hardware and
+are not ``grown'' automatically as is done for the normal stack.
+If the stack overflows and this space is not protected
+unpredictable results may occur.
+.Sh RETURN VALUES
+Upon successful completion, a value of 0 is returned.
+Otherwise, a value of -1 is returned and
+.Va errno
+is set to indicate the error.
+.Sh ERRORS
+.Fn Sigstack
+will fail and the signal stack context will remain unchanged
+if one of the following occurs.
+.Bl -tag -width [ENOMEM]
+.It Bq Er EFAULT
+Either
+.Fa ss
+or
+.Fa oss
+points to memory that is not a valid part of the process
+address space.
+.It Bq Er EINVAL
+An attempt was made to disable an active stack.
+.It Bq Er ENOMEM
+Size of alternate stack area is less than or equal to
+.Dv MINSIGSTKSZ .
+.El
+.Sh SEE ALSO
+.Xr sigaction 2 ,
+.Xr setjmp 3
+.Sh HISTORY
+The predecessor to
+.Nm sigaltstack ,
+the
+.Fn sigstack
+system call, appeared in
+.Bx 4.2 .