kernel/git/stable/linux.git/arch/s390/boot, branch master

s390/boot: Bound command line facility ranges

2026-09-01T10:44:48+00:00

The facilities and debug-alternative command line parsers iterate over inclusive numeric ranges. If a range ends at ULONG_MAX, incrementing the current value wraps to zero and the loop never terminates. Large finite out-of-range values also cause unnecessary early boot iterations even though the bitmap helpers ignore them. Stop each loop at the size of the bitmap it modifies. This preserves all meaningful range values while guaranteeing termination. Reviewed-by: Heiko Carstens Signed-off-by: Vasily Gorbik Signed-off-by: Heiko Carstens

s390/boot: Avoid IPL parameter append past command line

2026-09-01T10:44:48+00:00

A command line may occupy all but the terminating byte of COMMAND_LINE_SIZE. In that case append_ipl_block_parm() passes a zero size to the IPL parameter conversion helpers and points the destination one byte past early_command_line. The helpers subtract one from the unsigned size and write the converted parameter outside the command line buffer. Convert the IPL parameter in the command line parsing buffer first. A parameter beginning with '=' can then replace the existing command line regardless of its length, while other parameters are appended only when space remains. Fixes: 5ecb2da660ab ("s390: support command lines longer than 896 bytes") Reviewed-by: Heiko Carstens Signed-off-by: Vasily Gorbik Signed-off-by: Heiko Carstens

s390/boot: Fix physical memory search range

2026-09-01T10:44:47+00:00

search_mem_end() calculates the number of 1MB blocks with a signed int literal. CONFIG_MAX_PHYSMEM_BITS values of 51 and above either overflow the signed int or shift beyond its width. This produces an invalid search range when the binary-search memory detection fallback is used. Use an unsigned long literal so the full supported physical address range is represented. Fixes: 54c57795e848 ("s390/mem_detect: replace tprot loop with binary search") Reviewed-by: Heiko Carstens Signed-off-by: Vasily Gorbik Signed-off-by: Heiko Carstens

s390/mm: Complete ptep_get() conversion

2026-06-16T15:30:31+00:00

Finalize commit c33c794828f2 ("mm: ptep_get() conversion") and replace direct page table entry dereferencing with the proper accessors (ptep_get(), pmdp_get(), etc.). Override the default getter implementations even though they are currently identical: pud_clear(), p4d_clear(), and pgd_clear() require corresponding architecture-specific getters, but these are not yet defined. This avoids a dependency loop. Acked-by: Heiko Carstens Signed-off-by: Alexander Gordeev

s390/string: Convert memset(16|32|64)() to C

2026-06-10T14:55:21+00:00

Convert memset(16|32|64)() from assembler to C, which should make it easier to read and change, if required. And it allows the compiler to optimize the code, and use different instructions, except for the used inline assemblies. Reviewed-by: Juergen Christ Signed-off-by: Heiko Carstens Signed-off-by: Alexander Gordeev

s390/string: Add -ffreestanding compile option to string.o

2026-06-10T14:55:20+00:00

Use -ffreestanding for string.o to avoid that the compiler generates calls into themselves for standard library functions like memset(). Reviewed-by: Juergen Christ Signed-off-by: Heiko Carstens Signed-off-by: Alexander Gordeev

s390: Add .noinstr.text to boot and purgatory linker scripts

2026-06-10T14:55:20+00:00

Upcoming changes will result in a .noinstr.text section within the boot and purgatory string.o binary. Explicitly add the new section to avoid orphaned warnings from the linker. Reviewed-by: Juergen Christ Signed-off-by: Heiko Carstens Signed-off-by: Alexander Gordeev

s390/boot: Respect kaslr_enabled() for identity randomization

2026-03-05T20:08:50+00:00

CONFIG_RANDOMIZE_IDENTITY_BASE only enables support for randomizing the identity mapping base. The randomization (identity base != 0) itself should happen only when KASLR is enabled at runtime. Guard the __identity_base update with kaslr_enabled() so nokaslr (and other KASLR-disabled cases) keep the non-randomized identity mapping at 0. Reviewed-by: Heiko Carstens Signed-off-by: Vasily Gorbik

Merge tag 's390-7.0-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

2026-02-10T04:17:03+00:00

Pull s390 updates from Heiko Carstens: - Drop support for outdated 3590/3592 and 3480 tape devices, and limit support to virtualized 3490E types devices - Implement exception based WARN() and WARN_ONCE() similar to x86 - Slightly optimize preempt primitives like __preempt_count_add() and __preempt_count_dec_and_test() - A couple of small fixes and improvements * tag 's390-7.0-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (35 commits) s390/tape: Consolidate tape config options and modules s390/cio: Fix device lifecycle handling in css_alloc_subchannel() s390/tape: Rename tape_34xx.c to tape_3490.c s390/tape: Cleanup sense data analysis and error handling s390/tape: Remove 3480 tape device type s390/tape: Remove unused command definitions s390/tape: Remove special block id handling s390/tape: Remove tape load display support s390/tape: Remove support for 3590/3592 models s390/kexec: Emit an error message when cmdline is too long s390/configs: Enable BLK_DEV_NULL_BLK as module s390: Document s390 stackprotector support s390/perf: Disable register readout on sampling events s390/Kconfig: Define non-zero ILLEGAL_POINTER_VALUE s390/bug: Prevent tail-call optimization s390/bug: Skip __WARN_trap() in call traces s390/bug: Implement WARN_ONCE() s390/bug: Implement __WARN_printf() s390/traps: Copy monitor code to pt_regs s390/bug: Introduce and use monitor code macro ...

s390/Kconfig: Define non-zero ILLEGAL_POINTER_VALUE

2026-01-27T11:21:20+00:00

Define CONFIG_ILLEGAL_POINTER_VALUE to the eye-catching non-zero value of 0xdead000000000000, consistent with other architectures. Assert at compile-time that the poison pointers that include/linux/poison.h defines based on this illegal pointer are beyond the largest useful virtual addresses. Also, assert at compile-time that the range of poison pointers per include/linux/poison.h (currently a range of less than 0x10000 addresses) does not overlap with the range used for address handles for s390's non-MIO PCI instructions. This enables s390 to track the DMA mappings by the network stack's page_pool that was introduced with [0]. Other functional changes are not intended. Other archictectures have introduced this for various other reasons with commit 5c178472af24 ("riscv: define ILLEGAL_POINTER_VALUE for 64bit") commit f6853eb561fb ("powerpc/64: Define ILLEGAL_POINTER_VALUE for 64-bit") commit bf0c4e047324 ("arm64: kconfig: Move LIST_POISON to a safe value") commit a29815a333c6 ("core, x86: make LIST_POISON less deadly") [0] https://lore.kernel.org/all/20250409-page-pool-track-dma-v9-0-6a9ef2e0cba8@redhat.com/ Reviewed-by: Niklas Schnelle Signed-off-by: Gerd Bayer Acked-by: Alexander Gordeev Signed-off-by: Heiko Carstens