lwn.git/arch/s390/kernel/kexec_elf.c, branch docs-next

s390: kexec: initialize kexec_buf struct

2025-09-04T00:10:37+00:00

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

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: Fix file verification on S390

2019-09-10T12:27:51+00:00

I accidentally typoed this #ifdef, so verification would always be disabled. Signed-off-by: Matthew Garrett Reported-by: Philipp Rudo Signed-off-by: James Morris

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: Fix detection of text segment in ELF loader

2019-04-29T08:43:46+00:00

To register data for the next kernel (command line, oldmem_base, etc.) the current kernel needs to find the ELF segment that contains head.S. This is currently done by checking ifor 'phdr->p_paddr == 0'. This works fine for the current kernel build but in theory the first few pages could be skipped. Make the detection more robust by checking if the entry point lies within the segment. Signed-off-by: Philipp Rudo Signed-off-by: Martin Schwidefsky