kexec: make -a the default

AFAICT, there's no downside to this, and running into this each time
I want to kexec (and, presumably, a significant chunk of the population,
since lockdown is quite popular) on some machines,
then going to the manual, then finding out I want the /auto/ flag(!)
is quite annoying:
  # kexec -l /boot/vmlinuz-6.1.0-3-amd64 --initrd /boot/initrd.img-6.1.0-3-amd64 --reuse-cmdline
  kexec_load failed: Operation not permitted
  entry       = 0x46eff7760 flags = 0x3e0000
  nr_segments = 7
  segment[0].buf   = 0x557cd303efa0
  segment[0].bufsz = 0x70
  segment[0].mem   = 0x100000
  segment[0].memsz = 0x1000
  segment[1].buf   = 0x557cd3046fe0
  segment[1].bufsz = 0x190
  segment[1].mem   = 0x101000
  segment[1].memsz = 0x1000
  segment[2].buf   = 0x557cd303f6e0
  segment[2].bufsz = 0x30
  segment[2].mem   = 0x102000
  segment[2].memsz = 0x1000
  segment[3].buf   = 0x7f658fa37010
  segment[3].bufsz = 0x12a51b5
  segment[3].mem   = 0x46a55a000
  segment[3].memsz = 0x12a6000
  segment[4].buf   = 0x7f6590ce1210
  segment[4].bufsz = 0x7e99e0
  segment[4].mem   = 0x46b800000
  segment[4].memsz = 0x377c000
  segment[5].buf   = 0x557cd3039350
  segment[5].bufsz = 0x42fa
  segment[5].mem   = 0x46eff2000
  segment[5].memsz = 0x5000
  segment[6].buf   = 0x557cd3032000
  segment[6].bufsz = 0x70e0
  segment[6].mem   = 0x46eff7000
  segment[6].memsz = 0x9000

Closes: https://bugs.debian.org/1030248
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Signed-off-by: Simon Horman <horms@kernel.org>

2 files changed, 6 insertions, 6 deletions

diff --git a/kexec/kexec.8 b/kexec/kexec.8
index 3ebede6..66453b8 100644
--- a/kexec/kexec.8
+++ b/kexec/kexec.8
@@ -151,14 +151,14 @@ Specify that the new kernel is of this
 Specify that the new KEXEC_FILE_LOAD syscall should be used exclusively.
 .TP
 .BI \-c\ (\-\-kexec-syscall)
-Specify that the old KEXEC_LOAD syscall should be used exclusively (the default).
+Specify that the old KEXEC_LOAD syscall should be used exclusively.
 .TP
 .BI \-a\ (\-\-kexec-syscall-auto)
 Try the new KEXEC_FILE_LOAD syscall first and when it is not supported or the
 kernel does not understand the supplied image fall back to the old KEXEC_LOAD
 interface.
 
-There is no one single interface that always works.
+There is no one single interface that always works, so this is the default.
 
 KEXEC_FILE_LOAD is required on systems that use locked-down secure boot to
 verify the kernel signature.  KEXEC_LOAD may be also disabled in the kernel
diff --git a/kexec/kexec.c b/kexec/kexec.c
index 0e92d96..36bb2ad 100644
--- a/kexec/kexec.c
+++ b/kexec/kexec.c
@@ -1049,11 +1049,11 @@ void usage(void)
 	       "                      to original kernel.\n"
 	       " -s, --kexec-file-syscall Use file based syscall for kexec operation\n"
 	       " -c, --kexec-syscall  Use the kexec_load syscall for for compatibility\n"
-	       "                      with systems that don't support -s (default)\n"
+	       "                      with systems that don't support -s\n"
 	       " -a, --kexec-syscall-auto  Use file based syscall for kexec and fall\n"
 	       "                      back to the compatibility syscall when file based\n"
 	       "                      syscall is not supported or the kernel did not\n"
-	       "                      understand the image\n"
+	       "                      understand the image (default)\n"
 	       " -d, --debug          Enable debugging to help spot a failure.\n"
 	       " -S, --status         Return 1 if the type (by default crash) is loaded,\n"
 	       "                      0 if not.\n"
@@ -1407,8 +1407,8 @@ int main(int argc, char *argv[])
 	int do_ifdown = 0, skip_ifdown = 0;
 	int do_unload = 0;
 	int do_reuse_initrd = 0;
-	int do_kexec_file_syscall = 0;
-	int do_kexec_fallback = 0;
+	int do_kexec_file_syscall = 1;
+	int do_kexec_fallback = 1;
 	int skip_checks = 0;
 	int do_status = 0;
 	void *entry = 0;