kernel/linux.git/arch/s390/boot, branch v6.12.80

s390/mm: Do not map lowcore with identity mapping

2025-08-28T14:31:15+00:00

[ Upstream commit 93f616ff870a1fb7e84d472cad0af651b18f9f87 ] 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 Signed-off-by: Sasha Levin

s390/boot: Fix ESSA detection

2025-02-27T12:30:22+00:00

commit c3a589fd9fcbf295a7402a4b188dc9277d505f4f upstream. The cmma_test_essa() inline assembly uses tmp as input and output, however tmp is specified as output only, which allows the compiler to optimize the initialization of tmp away. Therefore the ESSA detection may or may not work depending on previous contents of the register that the compiler selected for tmp. Fix this by using the correct constraint modifier. Fixes: 468a3bc2b7b9 ("s390/cmma: move parsing of cmma kernel parameter to early boot code") Cc: stable@vger.kernel.org Signed-off-by: Heiko Carstens Reviewed-by: Vasily Gorbik Signed-off-by: Vasily Gorbik Signed-off-by: Greg Kroah-Hartman

Revert "s390/mm: Allow large pages for KASAN shadow mapping"

2025-02-08T08:58:18+00:00

commit cc00550b2ae7ab1c7c56669fc004a13d880aaf0a upstream. This reverts commit ff123eb7741638d55abf82fac090bb3a543c1e74. Allowing large pages for KASAN shadow mappings isn't inherently wrong, but adding POPULATE_KASAN_MAP_SHADOW to large_allowed() exposes an issue in can_large_pud() and can_large_pmd(). Since commit d8073dc6bc04 ("s390/mm: Allow large pages only for aligned physical addresses"), both can_large_pud() and can_large_pmd() call _pa() to check if large page physical addresses are aligned. However, _pa() has a side effect: it allocates memory in POPULATE_KASAN_MAP_SHADOW mode. This results in massive memory leaks. The proper fix would be to address both large_allowed() and _pa()'s side effects, but for now, revert this change to avoid the leaks. Fixes: ff123eb77416 ("s390/mm: Allow large pages for KASAN shadow mapping") Signed-off-by: Vasily Gorbik Signed-off-by: Heiko Carstens Signed-off-by: Greg Kroah-Hartman

s390/mm: Allow large pages for KASAN shadow mapping

2025-02-08T08:58:04+00:00

[ Upstream commit ff123eb7741638d55abf82fac090bb3a543c1e74 ] Commit c98d2ecae08f ("s390/mm: Uncouple physical vs virtual address spaces") introduced a large_allowed() helper that restricts which mapping modes can use large pages. This change unintentionally prevented KASAN shadow mappings from using large pages, despite there being no reason to avoid them. In fact, large pages are preferred for performance. Add POPULATE_KASAN_MAP_SHADOW to the allowed list in large_allowed() to restore large page mappings for KASAN shadows. While large_allowed() isn't strictly necessary with current mapping modes since disallowed modes either don't map anything or fail alignment and size checks, keep it for clarity. Fixes: c98d2ecae08f ("s390/mm: Uncouple physical vs virtual address spaces") Acked-by: Alexander Gordeev Signed-off-by: Vasily Gorbik Signed-off-by: Heiko Carstens Signed-off-by: Sasha Levin

s390/mm: Fix DirectMap accounting

2024-12-27T13:02:14+00:00

commit 41856638e6c4ed51d8aa9e54f70059d1e357b46e upstream. With uncoupling of physical and virtual address spaces population of the identity mapping was changed to use the type POPULATE_IDENTITY instead of POPULATE_DIRECT. This breaks DirectMap accounting: > cat /proc/meminfo DirectMap4k: 55296 kB DirectMap1M: 18446744073709496320 kB Adjust all locations of update_page_count() in vmem.c to use POPULATE_IDENTITY instead of POPULATE_DIRECT as well. With this accounting is correct again: > cat /proc/meminfo DirectMap4k: 54264 kB DirectMap1M: 8334336 kB Fixes: c98d2ecae08f ("s390/mm: Uncouple physical vs virtual address spaces") Cc: stable@vger.kernel.org Reviewed-by: Alexander Gordeev Signed-off-by: Heiko Carstens Signed-off-by: Alexander Gordeev Signed-off-by: Greg Kroah-Hartman

s390/mm: Consider KMSAN modules metadata for paging levels

2024-12-27T13:01:59+00:00

[ Upstream commit 282da38b465395c930687974627c24f47ddce5ff ] The calculation determining whether to use three- or four-level paging didn't account for KMSAN modules metadata. Include this metadata in the virtual memory size calculation to ensure correct paging mode selection and avoiding potentially unnecessary physical memory size limitations. Fixes: 65ca73f9fb36 ("s390/mm: define KMSAN metadata for vmalloc and modules") Acked-by: Heiko Carstens Reviewed-by: Alexander Gordeev Reviewed-by: Ilya Leoshkevich Signed-off-by: Vasily Gorbik Signed-off-by: Alexander Gordeev Signed-off-by: Sasha Levin

Merge tag 's390-6.12-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

2024-09-21T16:02:54+00:00

Pull s390 updates from Vasily Gorbik: - Optimize ftrace and kprobes code patching and avoid stop machine for kprobes if sequential instruction fetching facility is available - Add hiperdispatch feature to dynamically adjust CPU capacity in vertical polarization to improve scheduling efficiency and overall performance. Also add infrastructure for handling warning track interrupts (WTI), allowing for graceful CPU preemption - Rework crypto code pkey module and split it into separate, independent modules for sysfs, PCKMO, CCA, and EP11, allowing modules to load only when the relevant hardware is available - Add hardware acceleration for HMAC modes and the full AES-XTS cipher, utilizing message-security assist extensions (MSA) 10 and 11. It introduces new shash implementations for HMAC-SHA224/256/384/512 and registers the hardware-accelerated AES-XTS cipher as the preferred option. Also add clear key token support - Add MSA 10 and 11 processor activity instrumentation counters to perf and update PAI Extension 1 NNPA counters - Cleanup cpu sampling facility code and rework debug/WARN_ON_ONCE statements - Add support for SHA3 performance enhancements introduced with MSA 12 - Add support for the query authentication information feature of MSA 13 and introduce the KDSA CPACF instruction. Provide query and query authentication information in sysfs, enabling tools like cpacfinfo to present this data in a human-readable form - Update kernel disassembler instructions - Always enable EXPOLINE_EXTERN if supported by the compiler to ensure kpatch compatibility - Add missing warning handling and relocated lowcore support to the early program check handler - Optimize ftrace_return_address() and avoid calling unwinder - Make modules use kernel ftrace trampolines - Strip relocs from the final vmlinux ELF file to make it roughly 2 times smaller - Dump register contents and call trace for early crashes to the console - Generate ptdump address marker array dynamically - Fix rcu_sched stalls that might occur when adding or removing large amounts of pages at once to or from the CMM balloon - Fix deadlock caused by recursive lock of the AP bus scan mutex - Unify sync and async register save areas in entry code - Cleanup debug prints in crypto code - Various cleanup and sanitizing patches for the decompressor - Various small ftrace cleanups * tag 's390-6.12-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (84 commits) s390/crypto: Display Query and Query Authentication Information in sysfs s390/crypto: Add Support for Query Authentication Information s390/crypto: Rework RRE and RRF CPACF inline functions s390/crypto: Add KDSA CPACF Instruction s390/disassembler: Remove duplicate instruction format RSY_RDRU s390/boot: Move boot_printk() code to own file s390/boot: Use boot_printk() instead of sclp_early_printk() s390/boot: Rename decompressor_printk() to boot_printk() s390/boot: Compile all files with the same march flag s390: Use MARCH_HAS_*_FEATURES defines s390: Provide MARCH_HAS_*_FEATURES defines s390/facility: Disable compile time optimization for decompressor code s390/boot: Increase minimum architecture to z10 s390/als: Remove obsolete comment s390/sha3: Fix SHA3 selftests failures s390/pkey: Add AES xts and HMAC clear key token support s390/cpacf: Add MSA 10 and 11 new PCKMO functions s390/mm: Add cond_resched() to cmm_alloc/free_pages() s390/pai_ext: Update PAI extension 1 counters s390/pai_crypto: Add support for MSA 10 and 11 pai counters ...

s390/boot: Move boot_printk() code to own file

2024-09-07T15:12:43+00:00

Keep the printk code separate from the program check code and move boot_printk() and helper functions to own printk.c file. Reviewed-by: Sven Schnelle Signed-off-by: Heiko Carstens

s390/boot: Use boot_printk() instead of sclp_early_printk()

2024-09-07T15:12:43+00:00

Consistently use boot_printk() everywhere instead of sclp_early_printk() at some places. For some places it was required (e.g. als.c), in order to stay in code compiled for the same architecture level, for other places it is not obvious why sclp_early_printk() was used instead of decompressor_printk(). Given that the whole decompressor code is compiled for the same architecture level, there is no requirement left to use different printk functions. Reviewed-by: Sven Schnelle Signed-off-by: Heiko Carstens

s390/boot: Rename decompressor_printk() to boot_printk()

2024-09-07T15:12:42+00:00

Rename decompressor_printk() to boot_printk() just to have a shorter function name, which also makes the code more readable. Reviewed-by: Sven Schnelle Signed-off-by: Heiko Carstens