linux-stable.git/arch/s390/kernel/kexec_image.c, branch linux-rolling-stable

s390: kexec: initialize kexec_buf struct

2025-09-19T14:37:31+00:00

commit e67f0bd05519012eaabaae68618ffc4ed30ab680 upstream.

The kexec_buf structure was previously declared without initialization.
commit bf454ec31add ("kexec_file: allow to place kexec_buf randomly")
added a field that is always read but not consistently populated by all
architectures. This un-initialized field will contain garbage.

This is also triggering a UBSAN warning when the uninitialized data was
accessed:

	------------[ cut here ]------------
	UBSAN: invalid-load in ./include/linux/kexec.h:210:10
	load of value 252 is not a valid value for type '_Bool'

Zero-initializing kexec_buf at declaration ensures all fields are
cleanly set, preventing future instances of uninitialized memory being
used.

Link: https://lkml.kernel.org/r/20250827-kbuf_all-v1-3-1df9882bb01a@debian.org
Fixes: bf454ec31add ("kexec_file: allow to place kexec_buf randomly")
Signed-off-by: Breno Leitao 
Cc: Albert Ou 
Cc: Alexander Gordeev 
Cc: Alexandre Ghiti 
Cc: Baoquan He 
Cc: Catalin Marinas 
Cc: Christian Borntraeger 
Cc: Coiby Xu 
Cc: Heiko Carstens 
Cc: Palmer Dabbelt 
Cc: Paul Walmsley 
Cc: Sven Schnelle 
Cc: Vasily Gorbik 
Cc: Will Deacon 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Greg Kroah-Hartman

s390, crash: wrap crash dumping code into crash related ifdefs

2024-02-24T01:48:23+00:00

Now crash codes under kernel/ folder has been split out from kexec
code, crash dumping can be separated from kexec reboot in config
items on s390 with some adjustments.

Here wrap up crash dumping codes with CONFIG_CRASH_DUMP ifdeffery.

Link: https://lkml.kernel.org/r/20240124051254.67105-10-bhe@redhat.com
Signed-off-by: Baoquan He 
Cc: Al Viro 
Cc: Eric W. Biederman 
Cc: Hari Bathini 
Cc: Pingfan Liu 
Cc: Klara Modin 
Cc: Michael Kelley 
Cc: Nathan Chancellor 
Cc: Stephen Rothwell 
Cc: Yang Li 
Signed-off-by: Andrew Morton

kexec_file: split KEXEC_VERIFY_SIG into KEXEC_SIG and KEXEC_SIG_FORCE

2019-08-20T04:54:15+00:00

This is a preparatory patch for kexec_file_load() lockdown.  A locked down
kernel needs to prevent unsigned kernel images from being loaded with
kexec_file_load().  Currently, the only way to force the signature
verification is compiling with KEXEC_VERIFY_SIG.  This prevents loading
usigned images even when the kernel is not locked down at runtime.

This patch splits KEXEC_VERIFY_SIG into KEXEC_SIG and KEXEC_SIG_FORCE.
Analogous to the MODULE_SIG and MODULE_SIG_FORCE for modules, KEXEC_SIG
turns on the signature verification but allows unsigned images to be
loaded.  KEXEC_SIG_FORCE disallows images without a valid signature.

Signed-off-by: Jiri Bohac 
Signed-off-by: David Howells 
Signed-off-by: Matthew Garrett 
cc: kexec@lists.infradead.org
Signed-off-by: James Morris

s390/kexec_file: Create ipl report and pass to next kernel

2019-04-29T08:44:02+00:00

Signed-off-by: Philipp Rudo 
Signed-off-by: Martin Schwidefsky

s390/kexec_file: Signature verification prototype

2019-04-29T08:44:01+00:00

Add kernel signature verification to kexec_file. The verification is based
on module signature verification and works with kernel images signed via
scripts/sign-file.

Signed-off-by: Philipp Rudo 
Signed-off-by: Martin Schwidefsky

s390/kexec_file: Load new kernel to absolute 0

2019-04-29T08:44:00+00:00

The leading 64 kB of a kernel image doesn't contain any data needed to boot
the new kernel when it was loaded via kexec_file. Thus kexec_file currently
strips them off before loading the image. Keep the leading 64 kB in order
to be able to pass a ipl_report to the next kernel.

Signed-off-by: Philipp Rudo 
Signed-off-by: Martin Schwidefsky

s390/kexec_file: Unify loader code

2019-04-29T08:43:59+00:00

s390_image_load and s390_elf_load have the same code to load the different
components. Combine this functionality in one shared function.

While at it move kexec_file_update_kernel into the new function as well.

Signed-off-by: Philipp Rudo 
Signed-off-by: Martin Schwidefsky

s390/kexec_file: Simplify parmarea access

2019-04-29T08:43:57+00:00

Access the parmarea in head.S via a struct instead of individual offsets.

While at it make the fields in the parmarea .quads.

Signed-off-by: Philipp Rudo 
Signed-off-by: Martin Schwidefsky

s390/kexec_file: Add crash support to image loader

2018-04-16T07:10:22+00:00

Add support to load a crash kernel to the image loader. This requires
extending the purgatory.

Signed-off-by: Philipp Rudo 
Reviewed-by: Martin Schwidefsky 
Signed-off-by: Martin Schwidefsky

s390/kexec_file: Add image loader

2018-04-16T07:10:22+00:00

Add an image loader for kexec_file_load. For simplicity first skip crash
support. The functions defined in machine_kexec_file will later be shared
with the ELF loader.

Signed-off-by: Philipp Rudo 
Reviewed-by: Martin Schwidefsky 
Signed-off-by: Martin Schwidefsky