package/kexec: bump to version 2.0.27

For release announce, see:
https://lists.infradead.org/pipermail/kexec/2023-August/027830.html

This new version introduced a usage of memfd_create() in [1]. This
function was introduced in Kernel 3.17. Therefore, this commit adds
this new dependency. This direct use of memfd_create() requires a
glibc >= 2.27. As is, this version would no longer work with uclibc-ng
or musl libc. This commit also adds a patch to allow compilation with
glibc < 2.27, and also uclibc and musl. See the patch commit log for
more details.

[1] https://git.kernel.org/pub/scm/utils/kernel/kexec/kexec-tools.git/commit/?id=714fa11590febc9cf6fd3c6309374a040a05ebb0

Signed-off-by: Julien Olivain <ju.o@free.fr>
[yann.morin.1998@free.fr: add arch dependency to comment]
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>

package/kexec/0002-kexec-provide-a-memfd_create-wrapper-if-not-present-.patch

@@ -0,0 +1,113 @@
+From 417382aecd6964f97a0a0774a5cccd29c1b9edb3 Mon Sep 17 00:00:00 2001
+From: Julien Olivain <ju.o@free.fr>
+Date: Sat, 23 Sep 2023 13:09:23 +0200
+Subject: [PATCH] kexec: provide a memfd_create() wrapper if not present in
+ libc
+
+Commit 714fa115 "kexec/arm64: Simplify the code for zImage" introduced
+a use of the memfd_create() system call, included in version
+kexec-tools v2.0.27.
+
+This system call was introduced in kernel commit [1], first included
+in kernel v3.17 (released on 2014-10-05).
+
+The memfd_create() glibc wrapper function was added much later in
+commit [2], first included in glibc version 2.27 (released on
+2018-02-01).
+
+This direct use memfd_create() introduced a requirement on
+Kernel >= 3.17 and glibc >= 2.27.
+
+There is old toolchains like [3] for example (which ships gcc 7.3.1,
+glibc 2.25 and includes kernel v4.10 headers), that can still be used
+to build newer kernels. Even if such toolchains can be seen as
+outdated, they are is still claimed as supported by recent kernel.
+For example, Kernel v6.5.5 has a requirement on gcc version 5.1 and
+greater. See [4].
+
+Moreover, kexec-tools <= 2.0.26 could be compiled using recent
+toolchains with alternative libc (e.g. uclibc-ng, musl) which are not
+providing the memfd_create() wrapper.
+
+When compiling kexec-tools v2.0.27 with a toolchain not providing the
+memfd_create() syscall wrapper, the compilation fail with message:
+
+    kexec/kexec.c: In function 'copybuf_memfd':
+    kexec/kexec.c:645:7: warning: implicit declaration of function 'memfd_create'; did you mean 'SYS_memfd_create'? [-Wimplicit-function-declaration]
+      fd = memfd_create("kernel", MFD_ALLOW_SEALING);
+           ^~~~~~~~~~~~
+           SYS_memfd_create
+    kexec/kexec.c:645:30: error: 'MFD_ALLOW_SEALING' undeclared (first use in this function); did you mean '_PC_ALLOC_SIZE_MIN'?
+      fd = memfd_create("kernel", MFD_ALLOW_SEALING);
+                                  ^~~~~~~~~~~~~~~~~
+                                  _PC_ALLOC_SIZE_MIN
+
+In order to let kexec-tools compile in a wider range of configurations,
+this commit adds a memfd_create() function check in autoconf configure
+script, and adds a system call wrapper which will be used if the
+function is not available. With this commit, the environment
+requirement is relaxed to only kernel >= v3.17.
+
+Note: this issue was found in kexec-tools integration in Buildroot [5]
+using the command "utils/test-pkg -a -p kexec", which tests many
+toolchain/arch combinations.
+
+[1] https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=9183df25fe7b194563db3fec6dc3202a5855839c
+[2] https://sourceware.org/git/?p=glibc.git;a=commitdiff;h=59d2cbb1fe4b8601d5cbd359c3806973eab6c62d
+[3] https://releases.linaro.org/components/toolchain/binaries/7.3-2018.05/aarch64-linux-gnu/gcc-linaro-7.3.1-2018.05-x86_64_aarch64-linux-gnu.tar.xz
+[4] https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/tree/Documentation/process/changes.rst?h=v6.5.5#n32
+[5] https://buildroot.org/
+
+Upstream: https://lists.infradead.org/pipermail/kexec/2023-September/028168.html
+Signed-off-by: Julien Olivain <ju.o@free.fr>
+---
+ configure.ac  |  3 +++
+ kexec/kexec.c | 11 +++++++++++
+ 2 files changed, 14 insertions(+)
+
+diff --git a/configure.ac b/configure.ac
+index 192976c..212ef2c 100644
+--- a/configure.ac
++++ b/configure.ac
+@@ -208,6 +208,9 @@ if test "$ac_cv_lib_xenctrl_xc_kexec_load" = yes ; then
+ 		AC_MSG_NOTICE([The kexec_status call is not available]))
+ fi
+ 
++dnl Check if libc has the memfd_create() syscall wrapper
++AC_CHECK_FUNCS([memfd_create])
++
+ dnl ---Sanity checks
+ if test "$CC"      = "no"; then AC_MSG_ERROR([cc not found]); fi
+ if test "$CPP"     = "no"; then AC_MSG_ERROR([cpp not found]); fi
+diff --git a/kexec/kexec.c b/kexec/kexec.c
+index c3b182e..c44c4b7 100644
+--- a/kexec/kexec.c
++++ b/kexec/kexec.c
+@@ -31,6 +31,10 @@
+ #include <sys/mount.h>
+ #include <sys/types.h>
+ #include <sys/stat.h>
++#ifndef HAVE_MEMFD_CREATE
++#include <linux/memfd.h>
++#include <sys/syscall.h>
++#endif
+ #include <sys/reboot.h>
+ #include <sys/mman.h>
+ #include <unistd.h>
+@@ -638,6 +642,13 @@ char *slurp_decompress_file(const char *filename, off_t *r_size)
+ 	return kernel_buf;
+ }
+ 
++#ifndef HAVE_MEMFD_CREATE
++static int memfd_create(const char *name, unsigned int flags)
++{
++	return syscall(SYS_memfd_create, name, flags);
++}
++#endif
++
+ static int copybuf_memfd(const char *kernel_buf, size_t size)
+ {
+ 	int fd, count;
+-- 
+2.41.0
+

package/kexec/Config.in

@@ -9,6 +9,7 @@ config BR2_PACKAGE_KEXEC_ARCH_SUPPORTS
 config BR2_PACKAGE_KEXEC
 	bool "kexec"
 	depends on BR2_PACKAGE_KEXEC_ARCH_SUPPORTS
+	depends on BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_17 # memfd_create()
 	help
 	  Kexec is a user space utility for loading another kernel
 	  and asking the currently running kernel to do something with
@@ -25,3 +26,7 @@ config BR2_PACKAGE_KEXEC_ZLIB
 	  Support for compressed kernel images
 
 endif
+
+comment "kexec needs a toolchain w/ headers >= 3.17"
+	depends on BR2_PACKAGE_KEXEC_ARCH_SUPPORTS
+	depends on !BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_17

package/kexec/kexec.hash

@@ -1,4 +1,4 @@
 # From https://www.kernel.org/pub/linux/utils/kernel/kexec/sha256sums.asc
-sha256  7fe36a064101cd5c515e41b2be393dce3ca88adce59d6ee668e0af7c0c4570cd  kexec-tools-2.0.26.tar.xz
+sha256  38d78bcfa33a88928324b57dc81f50c1dfc279eede45e80957ca18f4e84b8187  kexec-tools-2.0.27.tar.xz
 # locally calculated
 sha256  fa5fc1d1eec39532ea517518eeefd7b6e3c14341a55e5880a0e2a49eee47a5b7  COPYING

package/kexec/kexec.mk

@@ -4,11 +4,13 @@
 #
 ################################################################################
 
-KEXEC_VERSION = 2.0.26
+KEXEC_VERSION = 2.0.27
 KEXEC_SOURCE = kexec-tools-$(KEXEC_VERSION).tar.xz
 KEXEC_SITE = $(BR2_KERNEL_MIRROR)/linux/utils/kernel/kexec
 KEXEC_LICENSE = GPL-2.0
 KEXEC_LICENSE_FILES = COPYING
+# 0002-kexec-provide-a-memfd_create-wrapper-if-not-present-.patch
+KEXEC_AUTORECONF = YES
 KEXEC_CPE_ID_PRODUCT = kexec-tools
 KEXEC_CPE_ID_VENDOR = kexec-tools_project
 KEXEC_SELINUX_MODULES = kdump