kernel/linux.git/arch/s390/boot, branch v6.18.22

s390/boot: Add -Wno-default-const-init-unsafe to KBUILD_CFLAGS

2026-03-04T12:19:33+00:00

[ Upstream commit 5ba35a6c13fff0929c34aba6b7602dacbe68686c ] Add -Wno-default-const-init-unsafe to boot KBUILD_CFLAGS, similar to scripts/Makefile.extrawarn, since clang generates warnings for the dummy variable in typecheck(): CC arch/s390/boot/version.o arch/s390/include/asm/ptrace.h:221:9: warning: default initialization of an object of type 'typeof (regs->psw)' (aka 'const psw_t') leaves the object uninitialized [-Wdefault-const-init-var-unsafe] 221 | return psw_bits(regs->psw).pstate; | ^ arch/s390/include/asm/ptrace.h:98:2: note: expanded from macro 'psw_bits' 98 | typecheck(psw_t, __psw); \ | ^ include/linux/typecheck.h:11:12: note: expanded from macro 'typecheck' 11 | typeof(x) __dummy2; \ | ^ Signed-off-by: Heiko Carstens Signed-off-by: Sasha Levin

s390/boot/vmlinux.lds.S: Ensure bzImage ends with SecureBoot trailer

2026-01-30T09:32:25+00:00

commit ddc6cbef3ef10359b5640b4ee810a520edc73586 upstream. Since commit 3e86e4d74c04 ("kbuild: keep .modinfo section in vmlinux.unstripped") the .modinfo section which has SHF_ALLOC ends up in bzImage after the SecureBoot trailer. This breaks SecureBoot because the bootloader can no longer find the SecureBoot trailer with kernel's signature at the expected location in bzImage. To fix the bug, move discarded sections before the ELF_DETAILS macro and discard the .modinfo section which is not needed by the decompressor. Fixes: 3e86e4d74c04 ("kbuild: keep .modinfo section in vmlinux.unstripped") Cc: stable@vger.kernel.org Suggested-by: Vasily Gorbik Reviewed-by: Vasily Gorbik Tested-by: Vasily Gorbik Signed-off-by: Alexander Egorenkov Signed-off-by: Heiko Carstens Signed-off-by: Greg Kroah-Hartman

Merge tag 's390-6.18-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

2025-09-30T02:14:25+00:00

Pull s390 updates from Alexander Gordeev: - Refactor SCLP memory hotplug code - Introduce common boot_panic() decompressor helper macro and use it to get rid of nearly few identical implementations - Take into account additional key generation flags and forward it to the ep11 implementation. With that allow users to modify the key generation process, e.g. provide valid combinations of XCP_BLOB_* flags - Replace kmalloc() + copy_from_user() with memdup_user_nul() in s390 debug facility and HMC driver - Add DAX support for DCSS memory block devices - Make the compiler statement attribute "assume" available with a new __assume macro - Rework ffs() and fls() family bitops functions, including source code improvements and generated code optimizations. Use the newly introduced __assume macro for that - Enable additional network features in default configurations - Use __GFP_ACCOUNT flag for user page table allocations to add missing kmemcg accounting - Add WQ_PERCPU flag to explicitly request the use of the per-CPU workqueue for 3590 tape driver - Switch power reading to the per-CPU and the Hiperdispatch to the default workqueue - Add memory allocation profiling hooks to allow better profiling data and the /proc/allocinfo output similar to other architectures * tag 's390-6.18-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (21 commits) s390/mm: Add memory allocation profiling hooks s390: Replace use of system_wq with system_dfl_wq s390/diag324: Replace use of system_wq with system_percpu_wq s390/tape: Add WQ_PERCPU to alloc_workqueue users s390/bitops: Switch to generic ffs() if supported by compiler s390/bitops: Switch to generic fls(), fls64(), etc. s390/mm: Use __GFP_ACCOUNT for user page table allocations s390/configs: Enable additional network features s390/bitops: Cleanup __flogr() s390/bitops: Use __assume() for __flogr() inline assembly return value compiler_types: Add __assume macro s390/bitops: Limit return value range of __flogr() s390/dcssblk: Add DAX support s390/hmcdrv: Replace kmalloc() + copy_from_user() with memdup_user_nul() s390/debug: Replace kmalloc() + copy_from_user() with memdup_user_nul() s390/pkey: Forward keygenflags to ep11_unwrapkey s390/boot: Add common boot_panic() code s390/bitops: Optimize inlining s390/bitops: Slightly optimize ffs() and fls64() s390/sclp: Move memory hotplug code for better modularity ...

s390/boot: Add common boot_panic() code

2025-08-28T14:52:54+00:00

Introduce a common boot_panic() helper macro, and use it to get rid of three more or less identical implementations. Signed-off-by: Heiko Carstens Reviewed-by: Alexander Gordeev Signed-off-by: Alexander Gordeev

s390/mm: Do not map lowcore with identity mapping

2025-08-20T14:37:28+00:00

Since the identity mapping is pinned to address zero the lowcore is always also mapped to address zero, this happens regardless of the relocate_lowcore command line option. If the option is specified the lowcore is mapped twice, instead of only once. This means that NULL pointer accesses will succeed instead of causing an exception (low address protection still applies, but covers only parts). To fix this never map the first two pages of physical memory with the identity mapping. Fixes: 32db401965f1 ("s390/mm: Pin identity mapping base to zero") Reviewed-by: Alexander Gordeev Signed-off-by: Heiko Carstens Signed-off-by: Alexander Gordeev

s390/boot: Fix startup debugging log

2025-08-06T15:18:27+00:00

Fix 'kernel image' end address for kaslr case. Fixes: ec6f9f7e5bbf ("s390/boot: Add startup debugging support") Reviewed-by: Alexander Gordeev Signed-off-by: Mikhail Zaslonko Signed-off-by: Heiko Carstens Signed-off-by: Alexander Gordeev

s390/boot: Introduce jump_to_kernel() function

2025-07-10T12:42:10+00:00

Introduce a global function that jumps from the decompressor to the decompressed kernel. Put its address into svc_old_psw, from where GDB can take it without loading decompressor symbols. It should be available throughout the entire decompressor execution, because it's placed there statically, and nothing in the decompressor uses the SVC instruction. Acked-by: Heiko Carstens Signed-off-by: Ilya Leoshkevich Tested-by: Alexander Gordeev Link: https://lore.kernel.org/r/20250625154220.75300-2-iii@linux.ibm.com Signed-off-by: Alexander Gordeev

s390/boot: Use -D__DISABLE_EXPORTS

2025-06-25T10:25:56+00:00

Files in the arch/s390/boot directory reuse logic from the rest of the kernel by including certain C and assembly files from the kernel and lib directories. Some of these included files contain EXPORT_SYMBOL directives. For instance, arch/s390/boot/cmdline.c includes lib/cmdline.c, which exports the get_option() function. This inclusion triggers genksyms processing for the files in arch/s390/boot, which is unnecessary and slows down the build. Additionally, when KBUILD_SYMTYPES=1 is set, the generated symtypes data contain exported symbols that are duplicated with the main kernel. This duplication can confuse external kABI tools that process the symtypes data. Address this issue by compiling the files in arch/s390/boot with -D__DISABLE_EXPORTS. Signed-off-by: Petr Pavlu Reviewed-by: Heiko Carstens Link: https://lore.kernel.org/r/20250620154649.116068-1-petr.pavlu@suse.com Signed-off-by: Alexander Gordeev

s390/boot: Use the full title of the manual for facility bits

2025-06-23T10:05:00+00:00

Also indicate the name of the section where facility bits are listed, because the manual has a length of 2124 pages. The current version is Fourteenth Edition (May, 2022) SA22-7832-13 Cc: Heiko Carstens Cc: Vasily Gorbik Cc: Alexander Gordeev Cc: Christian Borntraeger Cc: Sven Schnelle Cc: S390 ML Signed-off-by: Xose Vazquez Perez Acked-by: Heiko Carstens Link: https://lore.kernel.org/r/20250616163248.77951-1-xose.vazquez@gmail.com Signed-off-by: Alexander Gordeev

s390: Replace ASSEMBLY with ASSEMBLER in non-uapi headers

2025-06-16T14:23:02+00:00

While the GCC and Clang compilers already define __ASSEMBLER__ automatically when compiling assembler code, __ASSEMBLY__ is a macro that only gets defined by the Makefiles in the kernel. This is bad since macros starting with two underscores are names that are reserved by the C language. It can also be very confusing for the developers when switching between userspace and kernelspace coding, or when dealing with uapi headers that rather should use __ASSEMBLER__ instead. So let's now standardize on the __ASSEMBLER__ macro that is provided by the compilers. This is a completely mechanical patch (done with a simple "sed -i" statement), with some manual fixups done later while rebasing the patch. Signed-off-by: Thomas Huth Acked-by: Heiko Carstens Link: https://lore.kernel.org/r/20250611140046.137739-3-thuth@redhat.com Signed-off-by: Alexander Gordeev