Make start up more efficient by using close_range() to close fds

Resolves: RHEL-154768

Signed-off-by: Siteshwar Vashisht <svashisht@redhat.com>

lsof-close_range.patch

@@ -0,0 +1,50 @@
+diff --git a/00DIST b/00DIST
+index 9cd9c3b..08918a4 100644
+--- a/00DIST
++++ b/00DIST
+@@ -5208,5 +5208,13 @@ July 14, 2018
+ 		The target runs check.bash.
+ 
+ 
++		[linux] use close_range instead of calling close repeatedly
++		At the starting up, lsof closes its file descriptors greater
++		than 2 by calling close(2) repeatedly. As reported in #186,
++		it can take long time. Linux 5.9 introduced close_range(2).
++		The new system call can close multiple file descriptors faster.
++		@qianzhangyl reported the original issue (#186).
++
++
+ The lsof-org team at GitHub
+ November 11, 2020
+diff --git a/dialects/linux/dlsof.h b/dialects/linux/dlsof.h
+index 16f04e2..721ded4 100644
+--- a/dialects/linux/dlsof.h
++++ b/dialects/linux/dlsof.h
+@@ -71,6 +71,7 @@
+ #include <linux/if_ether.h>
+ #include <linux/netlink.h>
+ 
++#include <sys/syscall.h>
+ 
+ /*
+  * This definition is needed for the common function prototype definitions
+diff --git a/main.c b/main.c
+index e58aa1a..b52956c 100644
+--- a/main.c
++++ b/main.c
+@@ -127,8 +127,15 @@ main(argc, argv)
+ #if	defined(HAS_CLOSEFROM)
+ 	(void) closefrom(3);
+ #else	/* !defined(HAS_CLOSEFROM) */
++#if	defined(SYS_close_range)
++	if (MaxFd > 3 && syscall(SYS_close_range, 3, MaxFd - 1, 0) == 0)
++	    goto closed;
++#endif
+ 	for (i = 3; i < MaxFd; i++)
+ 	    (void) close(i);
++#if	defined(SYS_close_range)
++  closed:
++#endif
+ #endif	/* !defined(HAS_CLOSEFROM) */
+ 
+ 	while (((i = open("/dev/null", O_RDWR, 0)) >= 0) && (i < 2))

lsof.spec

@@ -1,7 +1,7 @@
 Summary: A utility which lists open files on a Linux/UNIX system
 Name: lsof
 Version: 4.94.0
-Release: 3%{?dist}
+Release: 4%{?dist}
 # Sendmail .. lib/snpf.c
 # LGPLv2+  .. lib/regex.c, regex.h
 License: zlib and Sendmail and LGPLv2+
@@ -19,6 +19,8 @@ Source1: upstream2downstream.sh
 
 # BZ#1260300 - move lsof man page to section 1
 Patch0: lsof-man-page-section.patch
+# RHEL-154768 - lsof spins on the CPU forever when *nofile* limit is high
+Patch1: lsof-close_range.patch
 
 BuildRequires: gcc
 BuildRequires: libselinux-devel
@@ -33,6 +35,7 @@ about files that are open by the processes running on a UNIX system.
 %prep
 %setup -q -n %{lsofrh}
 %patch0 -p1 -b .man-page-section
+%patch1 -p1 -b .lsof-close_range
 
 %build
 ./Configure -n linux
@@ -52,6 +55,10 @@ install -p -m 0644 lsof.1 ${RPM_BUILD_ROOT}%{_mandir}/man1/lsof.1
 %{_mandir}/man*/*
 
 %changelog
+* Fri Jul 03 2026 Siteshwar Vashisht <svashisht@redhat.com> - 4.94.0-4
+- Make start up more efficient by using close_range() to close fds
+  Resolves: RHEL-154768
+
 * Mon Aug 09 2021 Mohan Boddu <mboddu@redhat.com> - 4.94.0-3
 - Rebuilt for IMA sigs, glibc 2.34, aarch64 flags
   Related: rhbz#1991688