5 files changed, 154 insertions, 7 deletions
diff --git a/lib/libsys/Makefile.sys b/lib/libsys/Makefile.sys
index bd65b58083c2..1d1a4f1136ce 100644
--- a/lib/libsys/Makefile.sys
+++ b/lib/libsys/Makefile.sys
@@ -243,6 +243,7 @@ MAN+=	abort2.2 \
 	jail.2 \
 	kcmp.2 \
 	kenv.2 \
+	kexec_load.2 \
 	kill.2 \
 	kldfind.2 \
 	kldfirstmod.2 \
diff --git a/lib/libsys/kexec_load.2 b/lib/libsys/kexec_load.2
new file mode 100644
index 000000000000..c3d458f34100
--- /dev/null
+++ b/lib/libsys/kexec_load.2
@@ -0,0 +1,119 @@
+.\"
+.\" SPDX-License-Identifier: BSD-3-Clause
+.\"
+.\" Copyright (c) 2025	Juniper Networks, Inc.
+.\"
+.Dd October 29, 2025
+.Dt KEXEC_LOAD 2
+.Os
+.Sh NAME
+.Nm kexec_load
+.Nd prepare new kernel to reboot into
+.Sh SYNOPSIS
+.Lb libc
+.In sys/kexec.h
+.Ft int
+.Fn kexec_load "uint64_t entry" "unsigned long count" \
+ "struct kexec_segment *segments" "unsigned long flags"
+.Sh DESCRIPTION
+The
+.Fn kexec_load
+system call loads a new kernel that can be executed later by
+.Xr reboot 2 .
+Subsequent calls will replace previously loaded images.
+.Pp
+The
+.Fa flags
+argument is a bitmask of flags that control the operation of the call.
+This argument is present for compatibility with Linux, although it is currently
+unused and must be 0.
+.Pp
+The
+.Fa entry
+argument is the physical address of the entry point of the new kernel image.
+.Pp
+The
+.Fa count
+argument is the number of segments in the image, currently limited to 16.
+A value of 0 will unload the currently staged image, if one exists, without
+staging a new image.
+.Pp
+The
+.Fa segments
+argument is an array of
+.Fa count
+members of the following structure:
+.Bd -literal -offset indent
+struct  kexec_segment {
+    void *buf;
+    size_t bufsz;
+    vm_paddr_t mem;
+    vm_size_t memsz;
+};
+.Ed
+.Pp
+The
+.Va buf
+and
+.Va bufsz
+members specify a memory region in the caller's address space containing the
+source of the segment.
+The
+.Va mem
+and
+.Va memsz
+members specify the target physical region of the segment.
+.Va bufsz
+must be less than or equal to
+.Va memsz ,
+and
+.Va mem
+and
+.Va memsz
+must be page aligned.
+The region covered by
+.Va mem
+must be in the list covered by the
+.Va vm.phys_segs
+sysctl.
+.Pp
+The
+.Fn kexec_load
+system call stages the kernel image in safe memory along with all
+machine-dependent image data until
+.Xr reboot 2
+is called with the
+.Va RB_KEXEC
+flag to load the image and execute the new kernel.
+.Sh RETURN VALUES
+The
+.Fn kexec_load
+system call returns 0 on success.
+On failure, -1 is returned, and
+.Va errno
+is set to indicate the error.
+On success any previously loaded image is unloaded and replaced with the new
+image.
+On failure, the previously loaded image is unchanged.
+.Sh ERRORS
+The following errors may be returned:
+.Bl -tag -width Er
+.It Bq Er EINVAL
+Too many segments in image.
+.It Bq Er EINVAL
+The value of
+.Va bufsz
+is larger than
+.Va memsz
+in one or more segments.
+.It Bq Er EINVAL
+Machine-dependent load error.
+.It Bq Er EBUSY
+Another
+.Fn kexec_load
+call is in progress.
+.Sh HISTORY
+The
+.Nm
+system call appeared in
+.Fx 16.0 .
diff --git a/lib/libsys/pathconf.2 b/lib/libsys/pathconf.2
index 5a983a3a13e2..5348128be706 100644
--- a/lib/libsys/pathconf.2
+++ b/lib/libsys/pathconf.2
@@ -25,7 +25,7 @@
 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 .\" SUCH DAMAGE.
 .\"
-.Dd August 6, 2025
+.Dd October 31, 2025
 .Dt PATHCONF 2
 .Os
 .Sh NAME
@@ -180,7 +180,8 @@ Return 1 if named attributes are enabled for the file system, otherwise 0.
 .It Li _PC_HAS_NAMEDATTR
 Return 1 if one or more named attributes exist for the file, otherwise 0.
 .It Li _PC_HAS_HIDDENSYSTEM
-Return 1 if both
+Return 1 if all of the
+.Dv UF_ARCHIVE ,
 .Dv UF_HIDDEN
 and
 .Dv UF_SYSTEM
@@ -192,6 +193,9 @@ Returns the block size required for block cloning via
 .Xr copy_file_range 2
 for a file system if block cloning is supported,
 otherwise 0.
+.It Li _PC_CASE_INSENSITIVE
+Return 1 if the file system performs case insensitive lookups,
+otherwise 0.
 .El
 .Sh RETURN VALUES
 If the call to
diff --git a/lib/libsys/posix_fallocate.2 b/lib/libsys/posix_fallocate.2
index 8be075b41331..94858c4a0f90 100644
--- a/lib/libsys/posix_fallocate.2
+++ b/lib/libsys/posix_fallocate.2
@@ -25,7 +25,7 @@
 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 .\" SUCH DAMAGE.
 .\"
-.Dd March 30, 2020
+.Dd November 2, 2025
 .Dt POSIX_FALLOCATE 2
 .Os
 .Sh NAME
@@ -105,8 +105,7 @@ The
 .Fa len
 argument was less than or equal to zero, the
 .Fa offset
-argument was less than zero,
-or the operation is not supported by the file system.
+argument was less than zero.
 .It Bq Er EIO
 An I/O error occurred while reading from or writing to a file system.
 .It Bq Er EINTEGRITY
@@ -123,6 +122,8 @@ media.
 The file descriptor
 .Fa fd
 has insufficient rights.
+.It Bq Er EOPNOTSUPP
+The operation is not supported by the file system.
 .It Bq Er ESPIPE
 The
 .Fa fd
@@ -137,12 +138,29 @@ argument is associated with a pipe or FIFO.
 The
 .Fn posix_fallocate
 system call conforms to
-.St -p1003.1-2004 .
+.St -p1003.1-2024 .
 .Sh HISTORY
 The
 .Fn posix_fallocate
 function appeared in
 .Fx 9.0 .
+.Pp
+Previous versions of
+.Nm
+used
+.Er EINVAL
+to indicate that the operation is not supported by the file system, as specified
+in
+.St -p1003.1
+Base Specifications, Issue 7.
+.St -p1003.1
+Base Specifications, Issue 8 switched to requiring
+.Er EOPNOTSUPP
+for this error case.
+ZFS adopted the latter convention in
+.Fx 15.0 ,
+and the remaining filesystems in base adopted it in
+.Fx 15.1 .
 .Sh AUTHORS
 .Fn posix_fallocate
 and this manual page were initially written by
diff --git a/lib/libsys/reboot.2 b/lib/libsys/reboot.2
index f6c7bf6c83cc..54fa8b599cd5 100644
--- a/lib/libsys/reboot.2
+++ b/lib/libsys/reboot.2
@@ -25,7 +25,7 @@
 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 .\" SUCH DAMAGE.
 .\"
-.Dd July 10, 2018
+.Dd October 29, 2025
 .Dt REBOOT 2
 .Os
 .Sh NAME
@@ -126,6 +126,10 @@ on the console.
 is actually interpreted by the
 .Xr init 8
 program in the newly booted system.
+.It Dv RB_KEXEC
+Execute a new kernel loaded via
+.Fn kexec_load 2 .
+If no kernel was loaded, reboot as normal.
 .El
 .Pp
 When no options are given (i.e.,
@@ -149,6 +153,7 @@ variable
 The caller is not the super-user.
 .El
 .Sh SEE ALSO
+.Xr kexec_load 2 ,
 .Xr crash 8 ,
 .Xr halt 8 ,
 .Xr init 8 ,