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2025-01-26s390/boot: Rename physmem_alloc_top_down() to physmem_alloc_or_die()Vasily Gorbik
The new name better reflects the function's behavior, emphasizing that it will terminate execution if allocation fails. Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2025-01-26s390/mm: Allow large pages for KASAN shadow mappingVasily Gorbik
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. 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. Rename large_allowed() to large_page_mapping_allowed() and add POPULATE_KASAN_MAP_SHADOW to the allowed list to restore large page mappings for KASAN shadows. While large_page_mapping_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. Rename _pa() to resolve_pa_may_alloc() for clarity and to emphasize existing side effect. Rework can_large_pud()/can_large_pmd() to take the side effect into consideration and actually return physical address instead of just checking conditions. Fixes: c98d2ecae08f ("s390/mm: Uncouple physical vs virtual address spaces") Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2025-01-20Merge tag 's390-6.14-1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull s390 updates from Alexander Gordeev: - Select config option KASAN_VMALLOC if KASAN is enabled - Select config option VMAP_STACK unconditionally - Implement arch_atomic_inc() / arch_atomic_dec() functions which result in a single instruction if compiled for z196 or newer architectures - Make layering between atomic.h and atomic_ops.h consistent - Comment s390 preempt_count implementation - Remove pre MARCH_HAS_Z196_FEATURES preempt count implementation - GCC uses the number of lines of an inline assembly to calculate number of instructions and decide on inlining. Therefore remove superfluous new lines from a couple of inline assemblies. - Provide arch_atomic_*_and_test() implementations that allow the compiler to generate slightly better code. - Optimize __preempt_count_dec_and_test() - Remove __bootdata annotations from declarations in header files - Add missing include of <linux/smp.h> in abs_lowcore.h to provide declarations for get_cpu() and put_cpu() used in the code - Fix suboptimal kernel image base when running make kasan.config - Remove huge_pte_none() and huge_pte_none_mostly() as are identical to the generic variants - Remove unused PAGE_KERNEL_EXEC, SEGMENT_KERNEL_EXEC, and REGION3_KERNEL_EXEC defines - Simplify noexec page protection handling and change the page, segment and region3 protection definitions automatically if the instruction execution-protection facility is not available - Save one instruction and prefer EXRL instruction over EX in string, xor_*(), amode31 and other functions - Create /dev/diag misc device to fetch diagnose specific information from the kernel and provide it to userspace - Retrieve electrical power readings using DIAGNOSE 0x324 ioctl - Make ccw_device_get_ciw() consistent and use array indices instead of pointer arithmetic - s390/qdio: Move memory alloc/pointer arithmetic for slib and sl into one place - The sysfs core now allows instances of 'struct bin_attribute' to be moved into read-only memory. Make use of that in s390 code - Add missing TLB range adjustment in pud_free_tlb() - Improve topology setup by adding early polarization detection - Fix length checks in codepage_convert() function - The generic bitops implementation is nearly identical to the s390 one. Switch to the generic variant and decrease a bit the kernel image size - Provide an optimized arch_test_bit() implementation which makes use of flag output constraint. This generates slightly better code - Provide memory topology information obtanied with DIAGNOSE 0x310 using ioctl. - Various other small improvements, fixes, and cleanups Also, some changes came in through a merge of 'pci-device-recovery' branch: - Add PCI error recovery status mechanism - Simplify and document debug_next_entry() logic - Split private data allocation and freeing out of debug file open() and close() operations - Add debug_dump() function that gets a textual representation of a debug info (e.g. PCI recovery hardware error logs) - Add formatted content of pci_debug_msg_id to the PCI report * tag 's390-6.14-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (48 commits) s390/futex: Fix FUTEX_OP_ANDN implementation s390/diag: Add memory topology information via diag310 s390/bitops: Provide optimized arch_test_bit() s390/bitops: Switch to generic bitops s390/ebcdic: Fix length decrement in codepage_convert() s390/ebcdic: Fix length check in codepage_convert() s390/ebcdic: Use exrl instead of ex s390/amode31: Use exrl instead of ex s390/stackleak: Use exrl instead of ex in __stackleak_poison() s390/lib: Use exrl instead of ex in xor functions s390/topology: Improve topology detection s390/tlb: Add missing TLB range adjustment s390/pkey: Constify 'struct bin_attribute' s390/sclp: Constify 'struct bin_attribute' s390/pci: Constify 'struct bin_attribute' s390/ipl: Constify 'struct bin_attribute' s390/crypto/cpacf: Constify 'struct bin_attribute' s390/qdio: Move memory alloc/pointer arithmetic for slib and sl into one place s390/cio: Use array indices instead of pointer arithmetic s390/qdio: Rename feature flag aif_osa to aif_qdio ...
2024-12-17s390/mm: Simplify noexec page protection handlingHeiko Carstens
By default page protection definitions like PAGE_RX have the _PAGE_NOEXEC bit set. For older machines without the instruction execution protection facility this bit is not allowed to be used in page table entries, and therefore must be removed. This is done at a couple of page table walkers, but also at some but not all page table modification functions like ptep_modify_prot_commit(). Avoid all of this and change the page, segment and region3 protection definitions so that the noexec bit is masked out automatically if the instruction execution-protection facility is not available. This is similar to what also various other architectures do which had to solve the same problem. Reviewed-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Acked-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2024-12-15s390/mm: Consider KMSAN modules metadata for paging levelsVasily Gorbik
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 <hca@linux.ibm.com> Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Reviewed-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2024-12-10s390/Kconfig: Select KASAN_VMALLOC if KASAN is enabledHeiko Carstens
Reduce the number of to be considered config options and select KASAN_VMALLOC if KASAN is enabled. Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com> Reviewed-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2024-12-10s390/mm: Fix DirectMap accountingHeiko Carstens
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 <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2024-11-13s390/boot/physmem: Convert to use flag output macrosHeiko Carstens
Use flag output macros in inline asm to allow for better code generation if the compiler has support for the flag output constraint. Reviewed-by: Juergen Christ <jchrist@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-11-07s390/physmem_info: Query diag500(STORAGE LIMIT) to support QEMU/KVM memory ↵David Hildenbrand
devices To support memory devices under QEMU/KVM, such as virtio-mem, we have to prepare our kernel virtual address space accordingly and have to know the highest possible physical memory address we might see later: the storage limit. The good old SCLP interface is not suitable for this use case. In particular, memory owned by memory devices has no relationship to storage increments, it is always detected using the device driver, and unaware OSes (no driver) must never try making use of that memory. Consequently this memory is located outside of the "maximum storage increment"-indicated memory range. Let's use our new diag500 STORAGE_LIMIT subcode to query this storage limit that can exceed the "maximum storage increment", and use the existing interfaces (i.e., SCLP) to obtain information about the initial memory that is not owned+managed by memory devices. If a hypervisor does not support such memory devices, the address exposed through diag500 STORAGE_LIMIT will correspond to the maximum storage increment exposed through SCLP. To teach kdump on s390 to include memory owned by memory devices, there will be ways to query the relevant memory ranges from the device via a driver running in special kdump mode (like virtio-mem already implements to filter /proc/vmcore access so we don't end up reading from unplugged device blocks). Update setup_ident_map_size(), to clarify that there can be more than just online and standby memory. Tested-by: Mario Casquero <mcasquer@redhat.com> Signed-off-by: David Hildenbrand <david@redhat.com> Acked-by: Heiko Carstens <hca@linux.ibm.com> Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Tested-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Acked-by: Christian Borntraeger <borntraeger@linux.ibm.com> Link: https://lore.kernel.org/r/20241025141453.1210600-4-david@redhat.com Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-10-29s390/uv: Retrieve UV secrets sysfs supportSteffen Eiden
Reflect the updated content in the query information UVC to the sysfs at /sys/firmware/query * new UV-query sysfs entry for the maximum number of retrievable secrets the UV can store for one secure guest. * new UV-query sysfs entry for the maximum number of association secrets the UV can store for one secure guest. * max_secrets contains the sum of max association and max retrievable secrets. Reviewed-by: Christoph Schlameuss <schlameuss@linux.ibm.com> Signed-off-by: Steffen Eiden <seiden@linux.ibm.com> Link: https://lore.kernel.org/r/20241024062638.1465970-7-seiden@linux.ibm.com Signed-off-by: Janosch Frank <frankja@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-10-29s390/uv: Use a constant for more-data rcSteffen Eiden
Add a define for the UVC rc 0x0100 that indicates that a UV-call was successful but may serve more data if called with a larger buffer again. Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Reviewed-by: Janosch Frank <frankja@linux.ibm.com> Reviewed-by: Christoph Schlameuss <schlameuss@linux.ibm.com> Signed-off-by: Steffen Eiden <seiden@linux.ibm.com> Link: https://lore.kernel.org/r/20241024062638.1465970-2-seiden@linux.ibm.com Signed-off-by: Janosch Frank <frankja@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-10-25s390: Fix various typosHeiko Carstens
Run codespell on arch/s390 and drivers/s390 and fix all typos. Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-09-21Merge tag 's390-6.12-1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux 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 ...
2024-09-07s390/boot: Move boot_printk() code to own fileHeiko Carstens
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 <svens@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-09-07s390/boot: Use boot_printk() instead of sclp_early_printk()Heiko Carstens
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 <svens@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-09-07s390/boot: Rename decompressor_printk() to boot_printk()Heiko Carstens
Rename decompressor_printk() to boot_printk() just to have a shorter function name, which also makes the code more readable. Reviewed-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-09-07s390/boot: Compile all files with the same march flagHeiko Carstens
Only a couple of files of the decompressor are compiled with the minimum architecture level. This is problematic for potential function calls between compile units, especially if a target function is within a compile until compiled for a higher architecture level, since that may lead to an unexpected operation exception. Therefore compile all files of the decompressor for the same (minimum) architecture level. Reviewed-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-09-07s390/boot: Increase minimum architecture to z10Heiko Carstens
The decompressor code is partially compiled with march=z900 so it is possible to print an error message in case a kernel is booted on a machine which misses facilities to execute the kernel. Given that the decompressor code also includes header files from the core kernel this causes problems for inline assemblies and other code where the minimum assumed architecture level is set to z10 in the meantime. If such code is also used in the decompressor (e.g. inline functions) z900 support must be implemented again. In order to avoid this and to keep things simple just raise the minimum architecture level to z10 for the decompressor just like for the kernel. Reviewed-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-09-07s390/als: Remove obsolete commentHeiko Carstens
The bss section of the decompressor is part of the compressed kernel image since commit 980d5f9ab36b ("s390/boot: enable .bss section for compressed kernel"). Remove a now incorrect comment that states that the bss section must not be accessed. Reviewed-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-08-29s390/entry: Unify save_area_sync and save_area_asyncSven Schnelle
In the past two save areas existed because interrupt handlers and system call / program check handlers where entered with interrupts enabled. To prevent a handler from overwriting the save areas from the previous handler, interrupts used the async save area, while system call and program check handler used the sync save area. Since the removal of critical section cleanup from entry.S, handlers are entered with interrupts disabled. When the interrupts are re-enabled, the save area is no longer need. Therefore merge both save areas into one. Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2024-08-27s390/build: Avoid relocation information in final vmlinuxJens Remus
Since commit 778666df60f0 ("s390: compile relocatable kernel without -fPIE") the kernel vmlinux ELF file is linked with --emit-relocs to preserve all relocations, so that all absolute relocations can be extracted using the 'relocs' tool to adjust them during boot. Port and adapt Petr Pavlu's x86 commit 9d9173e9ceb6 ("x86/build: Avoid relocation information in final vmlinux") to s390 to strip all relocations from the final vmlinux ELF file to optimize its size. Following is his original commit message with minor adaptions for s390: The Linux build process on s390 roughly consists of compiling all input files, statically linking them into a vmlinux ELF file, and then taking and turning this file into an actual bzImage bootable file. vmlinux has in this process two main purposes: 1) It is an intermediate build target on the way to produce the final bootable image. 2) It is a file that is expected to be used by debuggers and standard ELF tooling to work with the built kernel. For the second purpose, a vmlinux file is typically collected by various package build recipes, such as distribution spec files, including the kernel's own tar-pkg target. When building the kernel vmlinux contains also relocation information produced by using the --emit-relocs linker option. This is utilized by subsequent build steps to create relocs.S and produce a relocatable image. However, the information is not needed by debuggers and other standard ELF tooling. The issue is then that the collected vmlinux file and hence distribution packages end up unnecessarily large because of this extra data. The following is a size comparison of vmlinux v6.10 with and without the relocation information: | Configuration | With relocs | Stripped relocs | | defconfig | 696 MB | 320 MB | | -CONFIG_DEBUG_INFO | 48 MB | 32 MB | Optimize a resulting vmlinux by adding a postlink step that splits the relocation information into relocs.S and then strips it from the vmlinux binary. Reviewed-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Jens Remus <jremus@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2024-08-22s390/boot: Fix KASLR base offset off by __START_KERNEL bytesAlexander Gordeev
Symbol offsets to the KASLR base do not match symbol address in the vmlinux image. That is the result of setting the KASLR base to the beginning of .text section as result of an optimization. Revert that optimization and allocate virtual memory for the whole kernel image including __START_KERNEL bytes as per the linker script. That allows keeping the semantics of the KASLR base offset in sync with other architectures. Rename __START_KERNEL to TEXT_OFFSET, since it represents the offset of the .text section within the kernel image, rather than a virtual address. Still skip mapping TEXT_OFFSET bytes to save memory on pgtables and provoke exceptions in case an attempt to access this area is made, as no kernel symbol may reside there. In case CONFIG_KASAN is enabled the location counter might exceed the value of TEXT_OFFSET, while the decompressor linker script forcefully resets it to TEXT_OFFSET, which leads to a sections overlap link failure. Use MAX() expression to avoid that. Reported-by: Omar Sandoval <osandov@osandov.com> Closes: https://lore.kernel.org/linux-s390/ZnS8dycxhtXBZVky@telecaster.dhcp.thefacebook.com/ Fixes: 56b1069c40c7 ("s390/boot: Rework deployment of the kernel image") Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> Acked-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2024-08-22s390/boot: Avoid possible physmem_info segment corruptionAlexander Gordeev
When physical memory for the kernel image is allocated it does not consider extra memory required for offsetting the image start to match it with the lower 20 bits of KASLR virtual base address. That might lead to kernel access beyond its memory range. Suggested-by: Vasily Gorbik <gor@linux.ibm.com> Fixes: 693d41f7c938 ("s390/mm: Restore mapping of kernel image using large pages") Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> Acked-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2024-08-21s390/mm: Pin identity mapping base to zeroAlexander Gordeev
SIE instruction performs faster when the virtual address of SIE block matches the physical one. Pin the identity mapping base to zero for the benefit of SIE and other instructions that have similar performance impact. Still, randomize the base when DEBUG_VM kernel configuration option is enabled. Suggested-by: Vasily Gorbik <gor@linux.ibm.com> Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2024-07-26Merge tag 's390-6.11-2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull more s390 updates from Vasily Gorbik: - Fix KMSAN build breakage caused by the conflict between s390 and mm-stable trees - Add KMSAN page markers for ptdump - Add runtime constant support - Fix __pa/__va for modules under non-GPL licenses by exporting necessary vm_layout struct with EXPORT_SYMBOL to prevent linkage problems - Fix an endless loop in the CF_DIAG event stop in the CPU Measurement Counter Facility code when the counter set size is zero - Remove the PROTECTED_VIRTUALIZATION_GUEST config option and enable its functionality by default - Support allocation of multiple MSI interrupts per device and improve logging of architecture-specific limitations - Add support for lowcore relocation as a debugging feature to catch all null ptr dereferences in the kernel address space, improving detection beyond the current implementation's limited write access protection - Clean up and rework CPU alternatives to allow for callbacks and early patching for the lowcore relocation * tag 's390-6.11-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (39 commits) s390: Remove protvirt and kvm config guards for uv code s390/boot: Add cmdline option to relocate lowcore s390/kdump: Make kdump ready for lowcore relocation s390/entry: Make system_call() ready for lowcore relocation s390/entry: Make ret_from_fork() ready for lowcore relocation s390/entry: Make __switch_to() ready for lowcore relocation s390/entry: Make restart_int_handler() ready for lowcore relocation s390/entry: Make mchk_int_handler() ready for lowcore relocation s390/entry: Make int handlers ready for lowcore relocation s390/entry: Make pgm_check_handler() ready for lowcore relocation s390/entry: Add base register to CHECK_VMAP_STACK/CHECK_STACK macro s390/entry: Add base register to SIEEXIT macro s390/entry: Add base register to MBEAR macro s390/entry: Make __sie64a() ready for lowcore relocation s390/head64: Make startup code ready for lowcore relocation s390: Add infrastructure to patch lowcore accesses s390/atomic_ops: Disable flag outputs constraint for GCC versions below 14.2.0 s390/entry: Move SIE indicator flag to thread info s390/nmi: Simplify ptregs setup s390/alternatives: Remove alternative facility list ...
2024-07-23Merge tag 'kbuild-v6.11' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull Kbuild updates from Masahiro Yamada: - Remove tristate choice support from Kconfig - Stop using the PROVIDE() directive in the linker script - Reduce the number of links for the combination of CONFIG_KALLSYMS and CONFIG_DEBUG_INFO_BTF - Enable the warning for symbol reference to .exit.* sections by default - Fix warnings in RPM package builds - Improve scripts/make_fit.py to generate a FIT image with separate base DTB and overlays - Improve choice value calculation in Kconfig - Fix conditional prompt behavior in choice in Kconfig - Remove support for the uncommon EMAIL environment variable in Debian package builds - Remove support for the uncommon "name <email>" form for the DEBEMAIL environment variable - Raise the minimum supported GNU Make version to 4.0 - Remove stale code for the absolute kallsyms - Move header files commonly used for host programs to scripts/include/ - Introduce the pacman-pkg target to generate a pacman package used in Arch Linux - Clean up Kconfig * tag 'kbuild-v6.11' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (65 commits) kbuild: doc: gcc to CC change kallsyms: change sym_entry::percpu_absolute to bool type kallsyms: unify seq and start_pos fields of struct sym_entry kallsyms: add more original symbol type/name in comment lines kallsyms: use \t instead of a tab in printf() kallsyms: avoid repeated calculation of array size for markers kbuild: add script and target to generate pacman package modpost: use generic macros for hash table implementation kbuild: move some helper headers from scripts/kconfig/ to scripts/include/ Makefile: add comment to discourage tools/* addition for kernel builds kbuild: clean up scripts/remove-stale-files kconfig: recursive checks drop file/lineno kbuild: rpm-pkg: introduce a simple changelog section for kernel.spec kallsyms: get rid of code for absolute kallsyms kbuild: Create INSTALL_PATH directory if it does not exist kbuild: Abort make on install failures kconfig: remove 'e1' and 'e2' macros from expression deduplication kconfig: remove SYMBOL_CHOICEVAL flag kconfig: add const qualifiers to several function arguments kconfig: call expr_eliminate_yn() at least once in expr_eliminate_dups() ...
2024-07-23s390: Remove protvirt and kvm config guards for uv codeJanosch Frank
Removing the CONFIG_PROTECTED_VIRTUALIZATION_GUEST ifdefs and config option as well as CONFIG_KVM ifdefs in uv files. Having this configurable has been more of a pain than a help. It's time to remove the ifdefs and the config option. Signed-off-by: Janosch Frank <frankja@linux.ibm.com> Acked-by: Christian Borntraeger <borntraeger@linux.ibm.com> Acked-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2024-07-23s390/boot: Add cmdline option to relocate lowcoreSven Schnelle
Now that everything has been converted, add the option 'relocate_lowcore' to enable relocating the lowcore. Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2024-07-23s390: Add infrastructure to patch lowcore accessesSven Schnelle
The s390 architecture defines two special per-CPU data pages called the "prefix area". In s390-linux terminology this is usually called "lowcore". This memory area contains system configuration data like old/new PSW's for system call/interrupt/machine check handlers and lots of other data. It is normally mapped to logical address 0. This area can only be accessed when in supervisor mode. This means that kernel code can dereference NULL pointers, because accesses to address 0 are allowed. Parts of lowcore can be write protected, but read accesses and write accesses outside of the write protected areas are not caught. To remove this limitation for debugging and testing, remap lowcore to another address and define a function get_lowcore() which simply returns the address where lowcore is mapped at. This would normally introduce a pointer dereference (=memory read). As lowcore is used for several very often used variables, add code to patch this function during runtime, so we avoid the memory reads. For C code get_lowcore() has to be used, for assembly code it is the GET_LC macro. When using this macro/function a reference is added to alternative patching. All these locations will be patched to the actual lowcore location when the kernel is booted or a module is loaded. To make debugging/bisecting problems easier, this patch adds all the infrastructure but the lowcore address is still hardwired to 0. This way the code can be converted on a per function basis, and the functionality is enabled in a patch after all the functions have been converted. Note that this requires at least z16 because the old lpsw instruction only allowed a 12 bit displacement. z16 introduced lpswey which allows 20 bits (signed), so the lowcore can effectively be mapped from address 0 - 0x7e000. To use 0x7e000 as address, a 6 byte lgfi instruction would have to be used in the alternative. To save two bytes, llilh can be used, but this only allows to set bits 16-31 of the address. In order to use the llilh instruction, use 0x70000 as alternative lowcore address. This is still large enough to catch NULL pointer dereferences into large arrays. Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2024-07-23s390/alternatives: Allow early alternative patching in decompressorSven Schnelle
Add the required code to patch alternatives early in the decompressor. This is required for the upcoming lowcore relocation changes, where alternatives for facility 193 need to get patched before lowcore alternatives. Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Co-developed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2024-07-23s390/boot: Do not assume the decompressor range is reservedAlexander Gordeev
When allocating a random memory range for .amode31 sections the minimal randomization address is 0. That does not lead to a possible overlap with the decompressor image (which also starts from 0) since by that time the image range is already reserved. Do not assume the decompressor range is reserved and always provide the minimal randomization address for .amode31 sections beyond the decompressor. That is a prerequisite for moving the lowcore memory address from NULL elsewhere. Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2024-07-21Merge tag 'mm-stable-2024-07-21-14-50' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: - In the series "mm: Avoid possible overflows in dirty throttling" Jan Kara addresses a couple of issues in the writeback throttling code. These fixes are also targetted at -stable kernels. - Ryusuke Konishi's series "nilfs2: fix potential issues related to reserved inodes" does that. This should actually be in the mm-nonmm-stable tree, along with the many other nilfs2 patches. My bad. - More folio conversions from Kefeng Wang in the series "mm: convert to folio_alloc_mpol()" - Kemeng Shi has sent some cleanups to the writeback code in the series "Add helper functions to remove repeated code and improve readability of cgroup writeback" - Kairui Song has made the swap code a little smaller and a little faster in the series "mm/swap: clean up and optimize swap cache index". - In the series "mm/memory: cleanly support zeropage in vm_insert_page*(), vm_map_pages*() and vmf_insert_mixed()" David Hildenbrand has reworked the rather sketchy handling of the use of the zeropage in MAP_SHARED mappings. I don't see any runtime effects here - more a cleanup/understandability/maintainablity thing. - Dev Jain has improved selftests/mm/va_high_addr_switch.c's handling of higher addresses, for aarch64. The (poorly named) series is "Restructure va_high_addr_switch". - The core TLB handling code gets some cleanups and possible slight optimizations in Bang Li's series "Add update_mmu_tlb_range() to simplify code". - Jane Chu has improved the handling of our fake-an-unrecoverable-memory-error testing feature MADV_HWPOISON in the series "Enhance soft hwpoison handling and injection". - Jeff Johnson has sent a billion patches everywhere to add MODULE_DESCRIPTION() to everything. Some landed in this pull. - In the series "mm: cleanup MIGRATE_SYNC_NO_COPY mode", Kefeng Wang has simplified migration's use of hardware-offload memory copying. - Yosry Ahmed performs more folio API conversions in his series "mm: zswap: trivial folio conversions". - In the series "large folios swap-in: handle refault cases first", Chuanhua Han inches us forward in the handling of large pages in the swap code. This is a cleanup and optimization, working toward the end objective of full support of large folio swapin/out. - In the series "mm,swap: cleanup VMA based swap readahead window calculation", Huang Ying has contributed some cleanups and a possible fixlet to his VMA based swap readahead code. - In the series "add mTHP support for anonymous shmem" Baolin Wang has taught anonymous shmem mappings to use multisize THP. By default this is a no-op - users must opt in vis sysfs controls. Dramatic improvements in pagefault latency are realized. - David Hildenbrand has some cleanups to our remaining use of page_mapcount() in the series "fs/proc: move page_mapcount() to fs/proc/internal.h". - David also has some highmem accounting cleanups in the series "mm/highmem: don't track highmem pages manually". - Build-time fixes and cleanups from John Hubbard in the series "cleanups, fixes, and progress towards avoiding "make headers"". - Cleanups and consolidation of the core pagemap handling from Barry Song in the series "mm: introduce pmd|pte_needs_soft_dirty_wp helpers and utilize them". - Lance Yang's series "Reclaim lazyfree THP without splitting" has reduced the latency of the reclaim of pmd-mapped THPs under fairly common circumstances. A 10x speedup is seen in a microbenchmark. It does this by punting to aother CPU but I guess that's a win unless all CPUs are pegged. - hugetlb_cgroup cleanups from Xiu Jianfeng in the series "mm/hugetlb_cgroup: rework on cftypes". - Miaohe Lin's series "Some cleanups for memory-failure" does just that thing. - Someone other than SeongJae has developed a DAMON feature in Honggyu Kim's series "DAMON based tiered memory management for CXL memory". This adds DAMON features which may be used to help determine the efficiency of our placement of CXL/PCIe attached DRAM. - DAMON user API centralization and simplificatio work in SeongJae Park's series "mm/damon: introduce DAMON parameters online commit function". - In the series "mm: page_type, zsmalloc and page_mapcount_reset()" David Hildenbrand does some maintenance work on zsmalloc - partially modernizing its use of pageframe fields. - Kefeng Wang provides more folio conversions in the series "mm: remove page_maybe_dma_pinned() and page_mkclean()". - More cleanup from David Hildenbrand, this time in the series "mm/memory_hotplug: use PageOffline() instead of PageReserved() for !ZONE_DEVICE". It "enlightens memory hotplug more about PageOffline() pages" and permits the removal of some virtio-mem hacks. - Barry Song's series "mm: clarify folio_add_new_anon_rmap() and __folio_add_anon_rmap()" is a cleanup to the anon folio handling in preparation for mTHP (multisize THP) swapin. - Kefeng Wang's series "mm: improve clear and copy user folio" implements more folio conversions, this time in the area of large folio userspace copying. - The series "Docs/mm/damon/maintaier-profile: document a mailing tool and community meetup series" tells people how to get better involved with other DAMON developers. From SeongJae Park. - A large series ("kmsan: Enable on s390") from Ilya Leoshkevich does that. - David Hildenbrand sends along more cleanups, this time against the migration code. The series is "mm/migrate: move NUMA hinting fault folio isolation + checks under PTL". - Jan Kara has found quite a lot of strangenesses and minor errors in the readahead code. He addresses this in the series "mm: Fix various readahead quirks". - SeongJae Park's series "selftests/damon: test DAMOS tried regions and {min,max}_nr_regions" adds features and addresses errors in DAMON's self testing code. - Gavin Shan has found a userspace-triggerable WARN in the pagecache code. The series "mm/filemap: Limit page cache size to that supported by xarray" addresses this. The series is marked cc:stable. - Chengming Zhou's series "mm/ksm: cmp_and_merge_page() optimizations and cleanup" cleans up and slightly optimizes KSM. - Roman Gushchin has separated the memcg-v1 and memcg-v2 code - lots of code motion. The series (which also makes the memcg-v1 code Kconfigurable) are "mm: memcg: separate legacy cgroup v1 code and put under config option" and "mm: memcg: put cgroup v1-specific memcg data under CONFIG_MEMCG_V1" - Dan Schatzberg's series "Add swappiness argument to memory.reclaim" adds an additional feature to this cgroup-v2 control file. - The series "Userspace controls soft-offline pages" from Jiaqi Yan permits userspace to stop the kernel's automatic treatment of excessive correctable memory errors. In order to permit userspace to monitor and handle this situation. - Kefeng Wang's series "mm: migrate: support poison recover from migrate folio" teaches the kernel to appropriately handle migration from poisoned source folios rather than simply panicing. - SeongJae Park's series "Docs/damon: minor fixups and improvements" does those things. - In the series "mm/zsmalloc: change back to per-size_class lock" Chengming Zhou improves zsmalloc's scalability and memory utilization. - Vivek Kasireddy's series "mm/gup: Introduce memfd_pin_folios() for pinning memfd folios" makes the GUP code use FOLL_PIN rather than bare refcount increments. So these paes can first be moved aside if they reside in the movable zone or a CMA block. - Andrii Nakryiko has added a binary ioctl()-based API to /proc/pid/maps for much faster reading of vma information. The series is "query VMAs from /proc/<pid>/maps". - In the series "mm: introduce per-order mTHP split counters" Lance Yang improves the kernel's presentation of developer information related to multisize THP splitting. - Michael Ellerman has developed the series "Reimplement huge pages without hugepd on powerpc (8xx, e500, book3s/64)". This permits userspace to use all available huge page sizes. - In the series "revert unconditional slab and page allocator fault injection calls" Vlastimil Babka removes a performance-affecting and not very useful feature from slab fault injection. * tag 'mm-stable-2024-07-21-14-50' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (411 commits) mm/mglru: fix ineffective protection calculation mm/zswap: fix a white space issue mm/hugetlb: fix kernel NULL pointer dereference when migrating hugetlb folio mm/hugetlb: fix possible recursive locking detected warning mm/gup: clear the LRU flag of a page before adding to LRU batch mm/numa_balancing: teach mpol_to_str about the balancing mode mm: memcg1: convert charge move flags to unsigned long long alloc_tag: fix page_ext_get/page_ext_put sequence during page splitting lib: reuse page_ext_data() to obtain codetag_ref lib: add missing newline character in the warning message mm/mglru: fix overshooting shrinker memory mm/mglru: fix div-by-zero in vmpressure_calc_level() mm/kmemleak: replace strncpy() with strscpy() mm, page_alloc: put should_fail_alloc_page() back behing CONFIG_FAIL_PAGE_ALLOC mm, slab: put should_failslab() back behind CONFIG_SHOULD_FAILSLAB mm: ignore data-race in __swap_writepage hugetlbfs: ensure generic_hugetlb_get_unmapped_area() returns higher address than mmap_min_addr mm: shmem: rename mTHP shmem counters mm: swap_state: use folio_alloc_mpol() in __read_swap_cache_async() mm/migrate: putback split folios when numa hint migration fails ...
2024-07-20kbuild: Abort make on install failuresZhang Bingwu
Setting '-e' flag tells shells to exit with error exit code immediately after any of commands fails, and causes make(1) to regard recipes as failed. Before this, make will still continue to succeed even after the installation failed, for example, for insufficient permission or directory does not exist. Signed-off-by: Zhang Bingwu <xtexchooser@duck.com> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2024-07-18Merge tag 's390-6.11-1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull s390 updates from Vasily Gorbik: - Remove restrictions on PAI NNPA and crypto counters, enabling concurrent per-task and system-wide sampling and counting events - Switch to GENERIC_CPU_DEVICES by setting up the CPU present mask in the architecture code and letting the generic code handle CPU bring-up - Add support for the diag204 busy indication facility to prevent undesirable blocking during hypervisor logical CPU utilization queries. Implement results caching - Improve the handling of Store Data SCLP events by suppressing unnecessary warning, preventing buffer release in I/O during failures, and adding timeout handling for Store Data requests to address potential firmware issues - Provide optimized __arch_hweight*() implementations - Remove the unnecessary CPU KOBJ_CHANGE uevents generated during topology updates, as they are unused and also not present on other architectures - Cleanup atomic_ops, optimize __atomic_set() for small values and __atomic_cmpxchg_bool() for compilers supporting flag output constraint - Couple of cleanups for KVM: - Move and improve KVM struct definitions for DAT tables from gaccess.c to a new header - Pass the asce as parameter to sie64a() - Make the crdte() and cspg() page table handling wrappers return a boolean to indicate success, like the other existing "compare and swap" wrappers - Add documentation for HWCAP flags - Switch to obtaining total RAM pages from memblock instead of totalram_pages() during mm init, to ensure correct calculation of zero page size, when defer_init is enabled - Refactor lowcore access and switch to using the get_lowcore() function instead of the S390_lowcore macro - Cleanups for PG_arch_1 and folio handling in UV and hugetlb code - Add missing MODULE_DESCRIPTION() macros - Fix VM_FAULT_HWPOISON handling in do_exception() * tag 's390-6.11-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (54 commits) s390/mm: Fix VM_FAULT_HWPOISON handling in do_exception() s390/kvm: Move bitfields for dat tables s390/entry: Pass the asce as parameter to sie64a() s390/sthyi: Use cached data when diag is busy s390/sthyi: Move diag operations s390/hypfs_diag: Diag204 busy loop s390/diag: Add busy-indication-facility requirements s390/diag: Diag204 add busy return errno s390/diag: Return errno's from diag204 s390/sclp: Diag204 busy indication facility detection s390/atomic_ops: Make use of flag output constraint s390/atomic_ops: Improve __atomic_set() for small values s390/atomic_ops: Use symbolic names s390/smp: Switch to GENERIC_CPU_DEVICES s390/hwcaps: Add documentation for HWCAP flags s390/pgtable: Make crdte() and cspg() return a value s390/topology: Remove CPU KOBJ_CHANGE uevents s390/sclp: Add timeout to Store Data requests s390/sclp: Prevent release of buffer in I/O s390/sclp: Suppress unnecessary Store Data warning ...
2024-07-03s390/string: add KMSAN supportIlya Leoshkevich
Add KMSAN support for the s390 implementations of the string functions. Do this similar to how it's already done for KASAN, except that the optimized memset{16,32,64}() functions need to be disabled: it's important for KMSAN to know that they initialized something. The way boot code is built with regard to string functions is problematic, since most files think it's configured with sanitizers, but boot/string.c doesn't. This creates various problems with the memset64() definitions, depending on whether the code is built with sanitizers or fortify. This should probably be streamlined, but in the meantime resolve the issues by introducing the IN_BOOT_STRING_C macro, similar to the existing IN_ARCH_STRING_C macro. Link: https://lkml.kernel.org/r/20240621113706.315500-33-iii@linux.ibm.com Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Reviewed-by: Alexander Potapenko <glider@google.com> Acked-by: Heiko Carstens <hca@linux.ibm.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christoph Lameter <cl@linux.com> Cc: David Rientjes <rientjes@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: <kasan-dev@googlegroups.com> Cc: Marco Elver <elver@google.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Masami Hiramatsu (Google) <mhiramat@kernel.org> Cc: Pekka Enberg <penberg@kernel.org> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Steven Rostedt (Google) <rostedt@goodmis.org> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-03s390/mm: define KMSAN metadata for vmalloc and modulesIlya Leoshkevich
The pages for the KMSAN metadata associated with most kernel mappings are taken from memblock by the common code. However, vmalloc and module metadata needs to be defined by the architectures. Be a little bit more careful than x86: allocate exactly MODULES_LEN for the module shadow and origins, and then take 2/3 of vmalloc for the vmalloc shadow and origins. This ensures that users passing small vmalloc= values on the command line do not cause module metadata collisions. Link: https://lkml.kernel.org/r/20240621113706.315500-32-iii@linux.ibm.com Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Reviewed-by: Alexander Potapenko <glider@google.com> Acked-by: Alexander Gordeev <agordeev@linux.ibm.com> Acked-by: Heiko Carstens <hca@linux.ibm.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christoph Lameter <cl@linux.com> Cc: David Rientjes <rientjes@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: <kasan-dev@googlegroups.com> Cc: Marco Elver <elver@google.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Masami Hiramatsu (Google) <mhiramat@kernel.org> Cc: Pekka Enberg <penberg@kernel.org> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Steven Rostedt (Google) <rostedt@goodmis.org> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-03s390/boot: add the KMSAN runtime stubIlya Leoshkevich
It should be possible to have inline functions in the s390 header files, which call kmsan_unpoison_memory(). The problem is that these header files might be included by the decompressor, which does not contain KMSAN runtime, causing linker errors. Not compiling these calls if __SANITIZE_MEMORY__ is not defined - either by changing kmsan-checks.h or at the call sites - may cause unintended side effects, since calling these functions from an uninstrumented code that is linked into the kernel is valid use case. One might want to explicitly distinguish between the kernel and the decompressor. Checking for a decompressor-specific #define is quite heavy-handed, and will have to be done at all call sites. A more generic approach is to provide a dummy kmsan_unpoison_memory() definition. This produces some runtime overhead, but only when building with CONFIG_KMSAN. The benefit is that it does not disturb the existing KMSAN build logic and call sites don't need to be changed. Link: https://lkml.kernel.org/r/20240621113706.315500-25-iii@linux.ibm.com Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Reviewed-by: Alexander Potapenko <glider@google.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christoph Lameter <cl@linux.com> Cc: David Rientjes <rientjes@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: <kasan-dev@googlegroups.com> Cc: Marco Elver <elver@google.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Masami Hiramatsu (Google) <mhiramat@kernel.org> Cc: Pekka Enberg <penberg@kernel.org> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Steven Rostedt (Google) <rostedt@goodmis.org> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-03s390/boot: turn off KMSANIlya Leoshkevich
All other sanitizers are disabled for boot as well. While at it, add a comment explaining why we need this. Link: https://lkml.kernel.org/r/20240621113706.315500-23-iii@linux.ibm.com Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Reviewed-by: Alexander Potapenko <glider@google.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christoph Lameter <cl@linux.com> Cc: David Rientjes <rientjes@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: <kasan-dev@googlegroups.com> Cc: Marco Elver <elver@google.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Masami Hiramatsu (Google) <mhiramat@kernel.org> Cc: Pekka Enberg <penberg@kernel.org> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Steven Rostedt (Google) <rostedt@goodmis.org> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-06-25s390/boot: Do not adjust GOT entries for undef weak symJens Remus
Since commit 778666df60f0 ("s390: compile relocatable kernel without -fPIE") and commit 00cda11d3b2e ("s390: Compile kernel with -fPIC and link with -no-pie") the kernel on s390x may have a Global Offset Table (GOT) whose entries are adjusted for KASLR in kaslr_adjust_got(). The GOT may contain entries for undefined weak symbols that resolved to zero. That is the resulting GOT entry value is zero. Adjusting those entries unconditionally in kaslr_adjust_got() is wrong. Otherwise the following sample code would erroneously assume foo to be defined, due to the adjustment changing the zero-value to a non-zero one: extern int foo __attribute__((weak)); if (*foo) /* foo is defined [or undefined and erroneously adjusted] */ The vmlinux build at commit 00cda11d3b2e ("s390: Compile kernel with -fPIC and link with -no-pie") with defconfig actually had two GOT entries for the undefined weak symbols __start_BTF and __stop_BTF: $ objdump -tw vmlinux | grep -F "*UND*" 0000000000000000 w *UND* 0000000000000000 __stop_BTF 0000000000000000 w *UND* 0000000000000000 __start_BTF $ readelf -rw vmlinux | grep -E "R_390_GOTENT +0{16}" 000000345760 2776a0000001a R_390_GOTENT 0000000000000000 __stop_BTF + 2 000000345766 2d5480000001a R_390_GOTENT 0000000000000000 __start_BTF + 2 The s390-specific vmlinux linker script sets the section start to __START_KERNEL, which is currently defined as 0x100000 on s390x. Access to lowcore is performed via a pointer of 0 and not a symbol in a section starting at 0. The first 64K are reserved for the loader on s390x. Thus it is safe to assume that __START_KERNEL will never be 0. As a result there cannot be any defined symbols resolving to zero in the kernel. Note that the first three GOT entries are reserved for the dynamic loader on s390x. [1] In the kernel they are zero. Therefore no extra handling is required to skip these. Skip adjusting GOT entries with a value of zero in kaslr_adjust_got(). While at it update the comment when a GOT exists on s390x. Since commit 00cda11d3b2e ("s390: Compile kernel with -fPIC and link with -no-pie") it no longer only exists when compiling with Clang, but also with GCC. [1]: s390x ELF ABI, section "Global Offset Table", https://github.com/IBM/s390x-abi/releases Fixes: 778666df60f0 ("s390: compile relocatable kernel without -fPIE") Reviewed-by: Ilya Leoshkevich <iii@linux.ibm.com> Acked-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Acked-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Jens Remus <jremus@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2024-06-18s390/boot: Replace S390_lowcore by get_lowcore()Sven Schnelle
Replace all S390_lowcore usages in arch/s390/boot by get_lowcore(). Acked-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2024-06-11s390/mm: Restore mapping of kernel image using large pagesAlexander Gordeev
Since physical and virtual kernel address spaces are uncoupled the kernel image is not mapped using large segment pages anymore, which is a regression. Put the kernel image at the same large segment page offset in physical memory as in virtual memory. Such approach preserves the existing number of bits of entropy used for randomization of the kernel location in virtual memory when KASLR is on. As result, the kernel is mapped using large segment pages. Fixes: c98d2ecae08f ("s390/mm: Uncouple physical vs virtual address spaces") Reported-by: Heiko Carstens <hca@linux.ibm.com> Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2024-06-11s390/mm: Allow large pages only for aligned physical addressesAlexander Gordeev
Do not allow creation of large pages against physical addresses, which itself are not aligned on the correct boundary. Failure to do so might lead to referencing wrong memory as result of the way DAT works. Fixes: c98d2ecae08f ("s390/mm: Uncouple physical vs virtual address spaces") Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2024-05-16s390/boot: Remove alt_stfle_fac_list from decompressorSven Schnelle
It is nowhere used in the decompressor, therefore remove it. Fixes: 17e89e1340a3 ("s390/facilities: move stfl information from lowcore to global data") Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-04-29s390: Compile kernel with -fPIC and link with -no-pieSumanth Korikkar
When the kernel is built with CONFIG_PIE_BUILD option enabled it uses dynamic symbols, for which the linker does not allow more than 64K number of entries. This can break features like kpatch. Hence, whenever possible the kernel is built with CONFIG_PIE_BUILD option disabled. For that support of unaligned symbols generated by linker scripts in the compiler is necessary. However, older compilers might lack such support. In that case the build process resorts to CONFIG_PIE_BUILD option-enabled build. Compile object files with -fPIC option and then link the kernel binary with -no-pie linker option. As result, the dynamic symbols are not generated and not only kpatch feature succeeds, but also the whole CONFIG_PIE_BUILD option-enabled code could be dropped. [ agordeev: Reworded the commit message ] Suggested-by: Ulrich Weigand <ulrich.weigand@de.ibm.com> Signed-off-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2024-04-17s390/boot: Do not rescue .vmlinux.relocs sectionAlexander Gordeev
The .vmlinux.relocs section is moved in front of the compressed kernel. The interim section rescue step is avoided as result. Suggested-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2024-04-17s390/boot: Rework deployment of the kernel imageAlexander Gordeev
Rework deployment of kernel image for both compressed and uncompressed variants as defined by CONFIG_KERNEL_UNCOMPRESSED kernel configuration variable. In case CONFIG_KERNEL_UNCOMPRESSED is disabled avoid uncompressing the kernel to a temporary buffer and copying it to the target address. Instead, uncompress it directly to the target destination. In case CONFIG_KERNEL_UNCOMPRESSED is enabled avoid moving the kernel to default 0x100000 location when KASLR is disabled or failed. Instead, use the uncompressed kernel image directly. In case KASLR is disabled or failed .amode31 section location in memory is not randomized and precedes the kernel image. In case CONFIG_KERNEL_UNCOMPRESSED is disabled that location overlaps the area used by the decompression algorithm. That is fine, since that area is not used after the decompression finished and the size of .amode31 section is not expected to exceed BOOT_HEAP_SIZE ever. There is no decompression in case CONFIG_KERNEL_UNCOMPRESSED is enabled. Therefore, rename decompress_kernel() to deploy_kernel(), which better describes both uncompressed and compressed cases. Introduce AMODE31_SIZE macro to avoid immediate value of 0x3000 (the size of .amode31 section) in the decompressor linker script. Modify the vmlinux linker script to force the size of .amode31 section to AMODE31_SIZE (the value of (_eamode31 - _samode31) could otherwise differ as result of compiler options used). Introduce __START_KERNEL macro that defines the kernel ELF image entry point and set it to the currrent value of 0x100000. Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2024-04-17s390: Map kernel at fixed location when KASLR is disabledAlexander Gordeev
Since kernel virtual and physical address spaces are uncoupled the kernel is mapped at the top of the virtual address space in case KASLR is disabled. That does not pose any issue with regard to the kernel booting and operation, but makes it difficult to use a generated vmlinux with some debugging tools (e.g. gdb), because the exact location of the kernel image in virtual memory is unknown. Make that location known and introduce CONFIG_KERNEL_IMAGE_BASE configuration option. A custom CONFIG_KERNEL_IMAGE_BASE value that would break the virtual memory layout leads to a build error. The kernel image size is defined by KERNEL_IMAGE_SIZE macro and set to 512 MB, by analogy with x86. Suggested-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2024-04-17s390/mm: Uncouple physical vs virtual address spacesAlexander Gordeev
The uncoupling physical vs virtual address spaces brings the following benefits to s390: - virtual memory layout flexibility; - closes the address gap between kernel and modules, it caused s390-only problems in the past (e.g. 'perf' bugs); - allows getting rid of trampolines used for module calls into kernel; - allows simplifying BPF trampoline; - minor performance improvement in branch prediction; - kernel randomization entropy is magnitude bigger, as it is derived from the amount of available virtual, not physical memory; The whole change could be described in two pictures below: before and after the change. Some aspects of the virtual memory layout setup are not clarified (number of page levels, alignment, DMA memory), since these are not a part of this change or secondary with regard to how the uncoupling itself is implemented. The focus of the pictures is to explain why __va() and __pa() macros are implemented the way they are. Memory layout in V==R mode: | Physical | Virtual | +- 0 --------------+- 0 --------------+ identity mapping start | | S390_lowcore | Low-address memory | +- 8 KB -----------+ | | | | | identity | phys == virt | | mapping | virt == phys | | | +- AMODE31_START --+- AMODE31_START --+ .amode31 rand. phys/virt start |.amode31 text/data|.amode31 text/data| +- AMODE31_END ----+- AMODE31_END ----+ .amode31 rand. phys/virt start | | | | | | +- __kaslr_offset, __kaslr_offset_phys| kernel rand. phys/virt start | | | | kernel text/data | kernel text/data | phys == kvirt | | | +------------------+------------------+ kernel phys/virt end | | | | | | | | | | | | +- ident_map_size -+- ident_map_size -+ identity mapping end | | | ... unused gap | | | +---- vmemmap -----+ 'struct page' array start | | | virtually mapped | | memory map | | | +- __abs_lowcore --+ | | | Absolute Lowcore | | | +- __memcpy_real_area | | | Real Memory Copy| | | +- VMALLOC_START --+ vmalloc area start | | | vmalloc area | | | +- MODULES_VADDR --+ modules area start | | | modules area | | | +------------------+ UltraVisor Secure Storage limit | | | ... unused gap | | | +KASAN_SHADOW_START+ KASAN shadow memory start | | | KASAN shadow | | | +------------------+ ASCE limit Memory layout in V!=R mode: | Physical | Virtual | +- 0 --------------+- 0 --------------+ | | S390_lowcore | Low-address memory | +- 8 KB -----------+ | | | | | | | | ... unused gap | | | | +- AMODE31_START --+- AMODE31_START --+ .amode31 rand. phys/virt start |.amode31 text/data|.amode31 text/data| +- AMODE31_END ----+- AMODE31_END ----+ .amode31 rand. phys/virt end (<2GB) | | | | | | +- __kaslr_offset_phys | kernel rand. phys start | | | | kernel text/data | | | | | +------------------+ | kernel phys end | | | | | | | | | | | | +- ident_map_size -+ | | | | ... unused gap | | | +- __identity_base + identity mapping start (>= 2GB) | | | identity | phys == virt - __identity_base | mapping | virt == phys + __identity_base | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | +---- vmemmap -----+ 'struct page' array start | | | virtually mapped | | memory map | | | +- __abs_lowcore --+ | | | Absolute Lowcore | | | +- __memcpy_real_area | | | Real Memory Copy| | | +- VMALLOC_START --+ vmalloc area start | | | vmalloc area | | | +- MODULES_VADDR --+ modules area start | | | modules area | | | +- __kaslr_offset -+ kernel rand. virt start | | | kernel text/data | phys == (kvirt - __kaslr_offset) + | | __kaslr_offset_phys +- kernel .bss end + kernel rand. virt end | | | ... unused gap | | | +------------------+ UltraVisor Secure Storage limit | | | ... unused gap | | | +KASAN_SHADOW_START+ KASAN shadow memory start | | | KASAN shadow | | | +------------------+ ASCE limit Unused gaps in the virtual memory layout could be present or not - depending on how partucular system is configured. No page tables are created for the unused gaps. The relative order of vmalloc, modules and kernel image in virtual memory is defined by following considerations: - start of the modules area and end of the kernel should reside within 4GB to accommodate relative 32-bit jumps. The best way to achieve that is to place kernel next to modules; - vmalloc and module areas should locate next to each other to prevent failures and extra reworks in user level tools (makedumpfile, crash, etc.) which treat vmalloc and module addresses similarily; - kernel needs to be the last area in the virtual memory layout to easily distinguish between kernel and non-kernel virtual addresses. That is needed to (again) simplify handling of addresses in user level tools and make __pa() macro faster (see below); Concluding the above, the relative order of the considered virtual areas in memory is: vmalloc - modules - kernel. Therefore, the only change to the current memory layout is moving kernel to the end of virtual address space. With that approach the implementation of __pa() macro is straightforward - all linear virtual addresses less than kernel base are considered identity mapping: phys == virt - __identity_base All addresses greater than kernel base are kernel ones: phys == (kvirt - __kaslr_offset) + __kaslr_offset_phys By contrast, __va() macro deals only with identity mapping addresses: virt == phys + __identity_base .amode31 section is mapped separately and is not covered by __pa() macro. In fact, it could have been handled easily by checking whether a virtual address is within the section or not, but there is no need for that. Thus, let __pa() code do as little machine cycles as possible. The KASAN shadow memory is located at the very end of the virtual memory layout, at addresses higher than the kernel. However, that is not a linear mapping and no code other than KASAN instrumentation or API is expected to access it. When KASLR mode is enabled the kernel base address randomized within a memory window that spans whole unused virtual address space. The size of that window depends from the amount of physical memory available to the system, the limit imposed by UltraVisor (if present) and the vmalloc area size as provided by vmalloc= kernel command line parameter. In case the virtual memory is exhausted the minimum size of the randomization window is forcefully set to 2GB, which amounts to in 15 bits of entropy if KASAN is enabled or 17 bits of entropy in default configuration. The default kernel offset 0x100000 is used as a magic value both in the decompressor code and vmlinux linker script, but it will be removed with a follow-up change. Acked-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2024-04-17s390/boot: Uncouple virtual and physical kernel offsetsAlexander Gordeev
This is a preparatory rework to allow uncoupling virtual and physical addresses spaces. Currently __kaslr_offset is the kernel offset in both physical memory on boot and in virtual memory after DAT mode is enabled. Uncouple these offsets and rename the physical address space variant to __kaslr_offset_phys while keep the name __kaslr_offset for the offset in virtual address space. Do not use __kaslr_offset_phys after DAT mode is enabled just yet, but still make it a persistent boot variable for later use. Use __kaslr_offset and __kaslr_offset_phys offsets in proper contexts and alter handle_relocs() function to distinguish between the two. Acked-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2024-04-17s390/mm: Create virtual memory layout structureAlexander Gordeev
This is a preparatory rework to allow uncoupling virtual and physical addresses spaces. Put virtual memory layout information into a structure to improve code generation when accessing the structure members, which are currently only ident_map_size and __kaslr_offset. Acked-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
generated by cgit (git 2.34.1) at 2025-07-18 08:20:15 +0000