Accepting request 1119956 from home:olh:branches:Kernel:kdump

- Fix build with old glibc with 6419b008fde783fd0cc2cc266bd1c9cf35e99a0e.patch

OBS-URL: https://build.opensuse.org/request/show/1119956
OBS-URL: https://build.opensuse.org/package/show/Kernel:kdump/kexec-tools?expand=0&rev=162

6419b008fde783fd0cc2cc266bd1c9cf35e99a0e.patch

@@ -0,0 +1,112 @@
+From 6419b008fde783fd0cc2cc266bd1c9cf35e99a0e Mon Sep 17 00:00:00 2001
+From: Julien Olivain <ju.o@free.fr>
+Date: Sat, 23 Sep 2023 18:46:06 +0200
+Subject: 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+outdated, they are is still claimed as supported by recent kernel.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/
+
+Signed-off-by: Julien Olivain <ju.o@free.fr>
+Signed-off-by: Simon Horman <horms@kernel.org>
+---
+ configure.ac  |  3 +++
+ kexec/kexec.c | 11 +++++++++++
+ 2 files changed, 14 insertions(+)
+
+diff --git a/configure.ac b/configure.ac
+index 352eefee..602de79b 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 fdb4c984..08edfca2 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>
+@@ -640,6 +644,13 @@ 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;
+-- 
+cgit 
+

kexec-tools.changes

@@ -1,3 +1,8 @@
+-------------------------------------------------------------------
+Tue Oct 24 11:11:11 UTC 2023 - olaf@aepfle.de
+
+- Fix build with old glibc with 6419b008fde783fd0cc2cc266bd1c9cf35e99a0e.patch
+
 -------------------------------------------------------------------
 Wed Sep  6 09:10:09 UTC 2023 - Petr Tesařík <petr@tesarici.cz>
 

kexec-tools.spec

@@ -29,6 +29,7 @@ Source1:        https://kernel.org/pub/linux/utils/kernel/kexec/%{name}-%{versio
 Source2:        kexec-tools.keyring
 Source3:        kexec-load.service
 Source4:        %{name}-rpmlintrc
+Patch0:         6419b008fde783fd0cc2cc266bd1c9cf35e99a0e.patch
 Patch3:         %{name}-disable-test.patch
 Patch4:         %{name}-vmcoreinfo-in-xen.patch
 # https://patchwork.kernel.org/project/linux-riscv/patch/20190416123233.4779-1-mick@ics.forth.gr/