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* s390/entry: align system call table on 8 bytesSumanth Korikkar2024-04-031-0/+1
| | | | | | | | | | | | Align system call table on 8 bytes. With sys_call_table entry size of 8 bytes that eliminates the possibility of a system call pointer crossing cache line boundary. Cc: stable@kernel.org Suggested-by: Ulrich Weigand <ulrich.weigand@de.ibm.com> Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
* s390/pai: fix sampling event removal for PMU device driverThomas Richter2024-04-032-6/+14
| | | | | | | | | | | | | | | In case of a sampling event, the PAI PMU device drivers need a reference to this event. Currently to PMU device driver reference is removed when a sampling event is destroyed. This may lead to situations where the reference of the PMU device driver is removed while being used by a different sampling event. Reset the event reference pointer of the PMU device driver when a sampling event is deleted and before the next one might be added. Fixes: 39d62336f5c1 ("s390/pai: add support for cryptography counters") Signed-off-by: Thomas Richter <tmricht@linux.ibm.com> Acked-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
* Merge tag 's390-6.9-2' of ↵Linus Torvalds2024-03-193-45/+34
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull more s390 updates from Heiko Carstens: - Various virtual vs physical address usage fixes - Add new bitwise types and helper functions and use them in s390 specific drivers and code to make it easier to find virtual vs physical address usage bugs. Right now virtual and physical addresses are identical for s390, except for module, vmalloc, and similar areas. This will be changed, hopefully with the next merge window, so that e.g. the kernel image and modules will be located close to each other, allowing for direct branches and also for some other simplifications. As a prerequisite this requires to fix all misuses of virtual and physical addresses. As it turned out people are so used to the concept that virtual and physical addresses are the same, that new bugs got added to code which was already fixed. In order to avoid that even more code gets merged which adds such bugs add and use new bitwise types, so that sparse can be used to find such usage bugs. Most likely the new types can go away again after some time - Provide a simple ARCH_HAS_DEBUG_VIRTUAL implementation - Fix kprobe branch handling: if an out-of-line single stepped relative branch instruction has a target address within a certain address area in the entry code, the program check handler may incorrectly execute cleanup code as if KVM code was executed, leading to crashes - Fix reference counting of zcrypt card objects - Various other small fixes and cleanups * tag 's390-6.9-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (41 commits) s390/entry: compare gmap asce to determine guest/host fault s390/entry: remove OUTSIDE macro s390/entry: add CIF_SIE flag and remove sie64a() address check s390/cio: use while (i--) pattern to clean up s390/raw3270: make class3270 constant s390/raw3270: improve raw3270_init() readability s390/tape: make tape_class constant s390/vmlogrdr: make vmlogrdr_class constant s390/vmur: make vmur_class constant s390/zcrypt: make zcrypt_class constant s390/mm: provide simple ARCH_HAS_DEBUG_VIRTUAL support s390/vfio_ccw_cp: use new address translation helpers s390/iucv: use new address translation helpers s390/ctcm: use new address translation helpers s390/lcs: use new address translation helpers s390/qeth: use new address translation helpers s390/zfcp: use new address translation helpers s390/tape: fix virtual vs physical address confusion s390/3270: use new address translation helpers s390/3215: use new address translation helpers ...
| * s390/entry: compare gmap asce to determine guest/host faultSven Schnelle2024-03-171-16/+15
| | | | | | | | | | | | | | | | | | | | | | | | With the current implementation, there are some cornercases where a host fault would be treated as a guest fault, for example when the sie instruction causes a program check. Therefore store the gmap asce in ptregs, and use that to compare the primary asce from the fault instead of matching instruction addresses. Suggested-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>
| * s390/entry: remove OUTSIDE macroSven Schnelle2024-03-171-25/+4
| | | | | | | | | | | | | | | | | | | | With only one OUTSIDE user left, remove the macro and move the code directly to the machine check handler. This has the advantage that it is much easier to determine which registers are used. Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * s390/entry: add CIF_SIE flag and remove sie64a() address checkSven Schnelle2024-03-171-3/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When a program check, interrupt or machine check is triggered, the PSW address is compared to a certain range of the sie64a() function to figure out whether SIE was interrupted and a cleanup of SIE is needed. This doesn't work with kprobes: If kprobes probes an instruction, it copies the instruction to the kprobes instruction page and overwrites the original instruction with an undefind instruction (Opcode 00). When this instruction is hit later, kprobes single-steps the instruction on the kprobes_instruction page. However, if this instruction is a relative branch instruction it will now point to a different location in memory due to being moved to the kprobes instruction page. If the new branch target points into sie64a() the kernel assumes it interrupted SIE when processing the breakpoint and will crash trying to access the SIE control block. Instead of comparing the address, introduce a new CIF_SIE flag which indicates whether SIE was interrupted. Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Suggested-by: Heiko Carstens <hca@linux.ibm.com> Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * s390/vtime: fix average steal time calculationMete Durlu2024-03-131-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Current average steal timer calculation produces volatile and inflated values. The only user of this value is KVM so far and it uses that to decide whether or not to yield the vCPU which is seeing steal time. KVM compares average steal timer to a threshold and if the threshold is past then it does not allow CPU polling and yields it to host, else it keeps the CPU by polling. Since KVM's steal time threshold is very low by default (%10) it most likely is not effected much by the bloated average steal timer values because the operating region is pretty small. However there might be new users in the future who might rely on this number. Fix average steal timer calculation by changing the formula from: avg_steal_timer = avg_steal_timer / 2 + steal_timer; to the following: avg_steal_timer = (avg_steal_timer + steal_timer) / 2; This ensures that avg_steal_timer is actually a naive average of steal timer values. It now closely follows steal timer values but of course in a smoother manner. Fixes: 152e9b8676c6 ("s390/vtime: steal time exponential moving average") Signed-off-by: Mete Durlu <meted@linux.ibm.com> Acked-by: Heiko Carstens <hca@linux.ibm.com> Acked-by: Christian Borntraeger <borntraeger@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * s390/sysinfo: allow response buffer in normal memoryAlexander Gordeev2024-03-131-1/+1
| | | | | | | | | | | | | | | | | | | | As provided with commit cd4386a931b63 ("s390/cpcmd,vmcp: avoid GFP_DMA allocations") the Diagnose Code 8 response buffer does not have to be below 2GB. Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
* | Merge tag 'mm-stable-2024-03-13-20-04' of ↵Linus Torvalds2024-03-146-15/+36
|\ \ | |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: - Sumanth Korikkar has taught s390 to allocate hotplug-time page frames from hotplugged memory rather than only from main memory. Series "implement "memmap on memory" feature on s390". - More folio conversions from Matthew Wilcox in the series "Convert memcontrol charge moving to use folios" "mm: convert mm counter to take a folio" - Chengming Zhou has optimized zswap's rbtree locking, providing significant reductions in system time and modest but measurable reductions in overall runtimes. The series is "mm/zswap: optimize the scalability of zswap rb-tree". - Chengming Zhou has also provided the series "mm/zswap: optimize zswap lru list" which provides measurable runtime benefits in some swap-intensive situations. - And Chengming Zhou further optimizes zswap in the series "mm/zswap: optimize for dynamic zswap_pools". Measured improvements are modest. - zswap cleanups and simplifications from Yosry Ahmed in the series "mm: zswap: simplify zswap_swapoff()". - In the series "Add DAX ABI for memmap_on_memory", Vishal Verma has contributed several DAX cleanups as well as adding a sysfs tunable to control the memmap_on_memory setting when the dax device is hotplugged as system memory. - Johannes Weiner has added the large series "mm: zswap: cleanups", which does that. - More DAMON work from SeongJae Park in the series "mm/damon: make DAMON debugfs interface deprecation unignorable" "selftests/damon: add more tests for core functionalities and corner cases" "Docs/mm/damon: misc readability improvements" "mm/damon: let DAMOS feeds and tame/auto-tune itself" - In the series "mm/mempolicy: weighted interleave mempolicy and sysfs extension" Rakie Kim has developed a new mempolicy interleaving policy wherein we allocate memory across nodes in a weighted fashion rather than uniformly. This is beneficial in heterogeneous memory environments appearing with CXL. - Christophe Leroy has contributed some cleanup and consolidation work against the ARM pagetable dumping code in the series "mm: ptdump: Refactor CONFIG_DEBUG_WX and check_wx_pages debugfs attribute". - Luis Chamberlain has added some additional xarray selftesting in the series "test_xarray: advanced API multi-index tests". - Muhammad Usama Anjum has reworked the selftest code to make its human-readable output conform to the TAP ("Test Anything Protocol") format. Amongst other things, this opens up the use of third-party tools to parse and process out selftesting results. - Ryan Roberts has added fork()-time PTE batching of THP ptes in the series "mm/memory: optimize fork() with PTE-mapped THP". Mainly targeted at arm64, this significantly speeds up fork() when the process has a large number of pte-mapped folios. - David Hildenbrand also gets in on the THP pte batching game in his series "mm/memory: optimize unmap/zap with PTE-mapped THP". It implements batching during munmap() and other pte teardown situations. The microbenchmark improvements are nice. - And in the series "Transparent Contiguous PTEs for User Mappings" Ryan Roberts further utilizes arm's pte's contiguous bit ("contpte mappings"). Kernel build times on arm64 improved nicely. Ryan's series "Address some contpte nits" provides some followup work. - In the series "mm/hugetlb: Restore the reservation" Breno Leitao has fixed an obscure hugetlb race which was causing unnecessary page faults. He has also added a reproducer under the selftest code. - In the series "selftests/mm: Output cleanups for the compaction test", Mark Brown did what the title claims. - Kinsey Ho has added the series "mm/mglru: code cleanup and refactoring". - Even more zswap material from Nhat Pham. The series "fix and extend zswap kselftests" does as claimed. - In the series "Introduce cpu_dcache_is_aliasing() to fix DAX regression" Mathieu Desnoyers has cleaned up and fixed rather a mess in our handling of DAX on archiecctures which have virtually aliasing data caches. The arm architecture is the main beneficiary. - Lokesh Gidra's series "per-vma locks in userfaultfd" provides dramatic improvements in worst-case mmap_lock hold times during certain userfaultfd operations. - Some page_owner enhancements and maintenance work from Oscar Salvador in his series "page_owner: print stacks and their outstanding allocations" "page_owner: Fixup and cleanup" - Uladzislau Rezki has contributed some vmalloc scalability improvements in his series "Mitigate a vmap lock contention". It realizes a 12x improvement for a certain microbenchmark. - Some kexec/crash cleanup work from Baoquan He in the series "Split crash out from kexec and clean up related config items". - Some zsmalloc maintenance work from Chengming Zhou in the series "mm/zsmalloc: fix and optimize objects/page migration" "mm/zsmalloc: some cleanup for get/set_zspage_mapping()" - Zi Yan has taught the MM to perform compaction on folios larger than order=0. This a step along the path to implementaton of the merging of large anonymous folios. The series is named "Enable >0 order folio memory compaction". - Christoph Hellwig has done quite a lot of cleanup work in the pagecache writeback code in his series "convert write_cache_pages() to an iterator". - Some modest hugetlb cleanups and speedups in Vishal Moola's series "Handle hugetlb faults under the VMA lock". - Zi Yan has changed the page splitting code so we can split huge pages into sizes other than order-0 to better utilize large folios. The series is named "Split a folio to any lower order folios". - David Hildenbrand has contributed the series "mm: remove total_mapcount()", a cleanup. - Matthew Wilcox has sought to improve the performance of bulk memory freeing in his series "Rearrange batched folio freeing". - Gang Li's series "hugetlb: parallelize hugetlb page init on boot" provides large improvements in bootup times on large machines which are configured to use large numbers of hugetlb pages. - Matthew Wilcox's series "PageFlags cleanups" does that. - Qi Zheng's series "minor fixes and supplement for ptdesc" does that also. S390 is affected. - Cleanups to our pagemap utility functions from Peter Xu in his series "mm/treewide: Replace pXd_large() with pXd_leaf()". - Nico Pache has fixed a few things with our hugepage selftests in his series "selftests/mm: Improve Hugepage Test Handling in MM Selftests". - Also, of course, many singleton patches to many things. Please see the individual changelogs for details. * tag 'mm-stable-2024-03-13-20-04' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (435 commits) mm/zswap: remove the memcpy if acomp is not sleepable crypto: introduce: acomp_is_async to expose if comp drivers might sleep memtest: use {READ,WRITE}_ONCE in memory scanning mm: prohibit the last subpage from reusing the entire large folio mm: recover pud_leaf() definitions in nopmd case selftests/mm: skip the hugetlb-madvise tests on unmet hugepage requirements selftests/mm: skip uffd hugetlb tests with insufficient hugepages selftests/mm: dont fail testsuite due to a lack of hugepages mm/huge_memory: skip invalid debugfs new_order input for folio split mm/huge_memory: check new folio order when split a folio mm, vmscan: retry kswapd's priority loop with cache_trim_mode off on failure mm: add an explicit smp_wmb() to UFFDIO_CONTINUE mm: fix list corruption in put_pages_list mm: remove folio from deferred split list before uncharging it filemap: avoid unnecessary major faults in filemap_fault() mm,page_owner: drop unnecessary check mm,page_owner: check for null stack_record before bumping its refcount mm: swap: fix race between free_swap_and_cache() and swapoff() mm/treewide: align up pXd_leaf() retval across archs mm/treewide: drop pXd_large() ...
| * arch, crash: move arch_crash_save_vmcoreinfo() out to file vmcore_info.cBaoquan He2024-02-233-15/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Nathan reported below building error: ===== $ curl -LSso .config https://git.alpinelinux.org/aports/plain/community/linux-edge/config-edge.armv7 $ make -skj"$(nproc)" ARCH=arm CROSS_COMPILE=arm-linux-gnueabi- olddefconfig all .. arm-linux-gnueabi-ld: arch/arm/kernel/machine_kexec.o: in function `arch_crash_save_vmcoreinfo': machine_kexec.c:(.text+0x488): undefined reference to `vmcoreinfo_append_str' ==== On architecutres, like arm, s390, ppc, sh, function arch_crash_save_vmcoreinfo() is located in machine_kexec.c and it can only be compiled in when CONFIG_KEXEC_CORE=y. That's not right because arch_crash_save_vmcoreinfo() is used to export arch specific vmcoreinfo. CONFIG_VMCORE_INFO is supposed to control its compiling in. However, CONFIG_VMVCORE_INFO could be independent of CONFIG_KEXEC_CORE, e.g CONFIG_PROC_KCORE=y will select CONFIG_VMVCORE_INFO. Or CONFIG_KEXEC/CONFIG_KEXEC_FILE is set while CONFIG_CRASH_DUMP is not set, it will report linking error. So, on arm, s390, ppc and sh, move arch_crash_save_vmcoreinfo out to a new file vmcore_info.c. Let CONFIG_VMCORE_INFO decide if compiling in arch_crash_save_vmcoreinfo(). [akpm@linux-foundation.org: remove stray newlines at eof] Link: https://lkml.kernel.org/r/20240129135033.157195-3-bhe@redhat.com Signed-off-by: Baoquan He <bhe@redhat.com> Reported-by: Nathan Chancellor <nathan@kernel.org> Closes: https://lore.kernel.org/all/20240126045551.GA126645@dev-arch.thelio-3990X/T/#u Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Hari Bathini <hbathini@linux.ibm.com> Cc: Klara Modin <klarasmodin@gmail.com> Cc: Michael Kelley <mhklinux@outlook.com> Cc: Pingfan Liu <piliu@redhat.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Yang Li <yang.lee@linux.alibaba.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * s390, crash: wrap crash dumping code into crash related ifdefsBaoquan He2024-02-233-0/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now crash codes under kernel/ folder has been split out from kexec code, crash dumping can be separated from kexec reboot in config items on s390 with some adjustments. Here wrap up crash dumping codes with CONFIG_CRASH_DUMP ifdeffery. Link: https://lkml.kernel.org/r/20240124051254.67105-10-bhe@redhat.com Signed-off-by: Baoquan He <bhe@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Hari Bathini <hbathini@linux.ibm.com> Cc: Pingfan Liu <piliu@redhat.com> Cc: Klara Modin <klarasmodin@gmail.com> Cc: Michael Kelley <mhklinux@outlook.com> Cc: Nathan Chancellor <nathan@kernel.org> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Yang Li <yang.lee@linux.alibaba.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* | Merge tag 's390-6.9-1' of ↵Linus Torvalds2024-03-1230-549/+503
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull s390 updates from Heiko Carstens: - Various virtual vs physical address usage fixes - Fix error handling in Processor Activity Instrumentation device driver, and export number of counters with a sysfs file - Allow for multiple events when Processor Activity Instrumentation counters are monitored in system wide sampling - Change multiplier and shift values of the Time-of-Day clock source to improve steering precision - Remove a couple of unneeded GFP_DMA flags from allocations - Disable mmap alignment if randomize_va_space is also disabled, to avoid a too small heap - Various changes to allow s390 to be compiled with LLVM=1, since ld.lld and llvm-objcopy will have proper s390 support witch clang 19 - Add __uninitialized macro to Compiler Attributes. This is helpful with s390's FPU code where some users have up to 520 byte stack frames. Clearing such stack frames (if INIT_STACK_ALL_PATTERN or INIT_STACK_ALL_ZERO is enabled) before they are used contradicts the intention (performance improvement) of such code sections. - Convert switch_to() to an out-of-line function, and use the generic switch_to header file - Replace the usage of s390's debug feature with pr_debug() calls within the zcrypt device driver - Improve hotplug support of the Adjunct Processor device driver - Improve retry handling in the zcrypt device driver - Various changes to the in-kernel FPU code: - Make in-kernel FPU sections preemptible - Convert various larger inline assemblies and assembler files to C, mainly by using singe instruction inline assemblies. This increases readability, but also allows makes it easier to add proper instrumentation hooks - Cleanup of the header files - Provide fast variants of csum_partial() and csum_partial_copy_nocheck() based on vector instructions - Introduce and use a lock to synchronize accesses to zpci device data structures to avoid inconsistent states caused by concurrent accesses - Compile the kernel without -fPIE. This addresses the following problems if the kernel is compiled with -fPIE: - It uses dynamic symbols (.dynsym), for which the linker refuses to allow more than 64k sections. This can break features which use '-ffunction-sections' and '-fdata-sections', including kpatch-build and function granular KASLR - It unnecessarily uses GOT relocations, adding an extra layer of indirection for many memory accesses - Fix shared_cpu_list for CPU private L2 caches, which incorrectly were reported as globally shared * tag 's390-6.9-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (117 commits) s390/tools: handle rela R_390_GOTPCDBL/R_390_GOTOFF64 s390/cache: prevent rebuild of shared_cpu_list s390/crypto: remove retry loop with sleep from PAES pkey invocation s390/pkey: improve pkey retry behavior s390/zcrypt: improve zcrypt retry behavior s390/zcrypt: introduce retries on in-kernel send CPRB functions s390/ap: introduce mutex to lock the AP bus scan s390/ap: rework ap_scan_bus() to return true on config change s390/ap: clarify AP scan bus related functions and variables s390/ap: rearm APQNs bindings complete completion s390/configs: increase number of LOCKDEP_BITS s390/vfio-ap: handle hardware checkstop state on queue reset operation s390/pai: change sampling event assignment for PMU device driver s390/boot: fix minor comment style damages s390/boot: do not check for zero-termination relocation entry s390/boot: make type of __vmlinux_relocs_64_start|end consistent s390/boot: sanitize kaslr_adjust_relocs() function prototype s390/boot: simplify GOT handling s390: vmlinux.lds.S: fix .got.plt assertion s390/boot: workaround current 'llvm-objdump -t -j ...' behavior ...
| * | s390/cache: prevent rebuild of shared_cpu_listHeiko Carstens2024-03-071-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With commit 36bbc5b4ffab ("cacheinfo: Allow early detection and population of cache attributes") the shared cpu list for each cache level higher than L1 is rebuilt even if the list already has been set up. This is caused by the removal of the cpumask_empty() check within cache_shared_cpu_map_setup(). However architectures can enforce that the shared cpu list is not rebuilt by simply setting cpu_map_populated of the per cpu cache info structure to true, which is also the fix for this problem. Before: $ cat /sys/devices/system/cpu/cpu1/cache/index2/shared_cpu_list 0-7 After: $ cat /sys/devices/system/cpu/cpu1/cache/index2/shared_cpu_list 1 Fixes: 36bbc5b4ffab ("cacheinfo: Allow early detection and population of cache attributes") Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/pai: change sampling event assignment for PMU device driverThomas Richter2024-03-072-3/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently only one PAI sampling event can be created and active at any one time. The PMU device drivers store a pointer to this event in their data structures even when the event is created for counting and the PMU device driver reference to this counting event is never needed. Change this and assign the pointer to the PMU device driver only when a sampling event is created. Signed-off-by: Thomas Richter <tmricht@linux.ibm.com> Acked-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/boot: simplify GOT handlingAlexander Gordeev2024-02-261-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The end of GOT is calculated dynamically on boot. The size of GOT is calculated on build from the start and end of GOT. Avoid both calculations and use the end of GOT directly. Acked-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Acked-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390: vmlinux.lds.S: fix .got.plt assertionHeiko Carstens2024-02-251-3/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Naresh reported this build error on linux-next: s390x-linux-gnu-ld: Unexpected GOT/PLT entries detected! make[3]: *** [/builds/linux/arch/s390/boot/Makefile:87: arch/s390/boot/vmlinux.syms] Error 1 make[3]: Target 'arch/s390/boot/bzImage' not remade because of errors. The reason for the build error is an incorrect/incomplete assertion which checks the size of the .got.plt section. Similar to x86 the size is either zero or 24 bytes (three entries). See commit 262b5cae67a6 ("x86/boot/compressed: Move .got.plt entries out of the .got section") for more details. The three reserved/additional entries for s390 are described in chapter 3.2.2 of the s390x ABI [1] (thanks to Andreas Krebbel for pointing this out!). [1] https://github.com/IBM/s390x-abi/releases/download/v1.6.1/lzsabi_s390x.pdf Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org> Reported-by: Linux Kernel Functional Testing <lkft@linaro.org> Closes: https://lore.kernel.org/all/CA+G9fYvWp8TY-fMEvc3UhoVtoR_eM5VsfHj3+n+kexcfJJ+Cvw@mail.gmail.com Fixes: 30226853d6ec ("s390: vmlinux.lds.S: explicitly handle '.got' and '.plt' sections") Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390: compile relocatable kernel without -fPIEJosh Poimboeuf2024-02-201-0/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | On s390, currently kernel uses the '-fPIE' compiler flag for compiling vmlinux. This has a few problems: - It uses dynamic symbols (.dynsym), for which the linker refuses to allow more than 64k sections. This can break features which use '-ffunction-sections' and '-fdata-sections', including kpatch-build [1] and Function Granular KASLR. - It unnecessarily uses GOT relocations, adding an extra layer of indirection for many memory accesses. Instead of using '-fPIE', resolve all the relocations at link time and then manually adjust any absolute relocations (R_390_64) during boot. This is done by first telling the linker to preserve all relocations during the vmlinux link. (Note this is harmless: they are later stripped in the vmlinux.bin link.) Then use the 'relocs' tool to find all absolute relocations (R_390_64) which apply to allocatable sections. The offsets of those relocations are saved in a special section which is then used to adjust the relocations during boot. (Note: For some reason, Clang occasionally creates a GOT reference, even without '-fPIE'. So Clang-compiled kernels have a GOT, which needs to be adjusted.) On my mostly-defconfig kernel, this reduces kernel text size by ~1.3%. [1] https://github.com/dynup/kpatch/issues/1284 [2] https://gcc.gnu.org/pipermail/gcc-patches/2023-June/622872.html [3] https://gcc.gnu.org/pipermail/gcc-patches/2023-August/625986.html Compiler consideration: Gcc recently implemented an optimization [2] for loading symbols without explicit alignment, aligning with the IBM Z ELF ABI. This ABI mandates symbols to reside on a 2-byte boundary, enabling the use of the larl instruction. However, kernel linker scripts may still generate unaligned symbols. To address this, a new -munaligned-symbols option has been introduced [3] in recent gcc versions. This option has to be used with future gcc versions. Older Clang lacks support for handling unaligned symbols generated by kernel linker scripts when the kernel is built without -fPIE. However, future versions of Clang will include support for the -munaligned-symbols option. When the support is unavailable, compile the kernel with -fPIE to maintain the existing behavior. In addition to it: move vmlinux.relocs to safe relocation When the kernel is built with CONFIG_KERNEL_UNCOMPRESSED, the entire uncompressed vmlinux.bin is positioned in the bzImage decompressor image at the default kernel LMA of 0x100000, enabling it to be executed in-place. However, the size of .vmlinux.relocs could be large enough to cause an overlap with the uncompressed kernel at the address 0x100000. To address this issue, .vmlinux.relocs is positioned after the .rodata.compressed in the bzImage. Nevertheless, in this configuration, vmlinux.relocs will overlap with the .bss section of vmlinux.bin. To overcome that, move vmlinux.relocs to a safe location before clearing .bss and handling relocs. Compile warning fix from Sumanth Korikkar: When kernel is built with CONFIG_LD_ORPHAN_WARN and -fno-PIE, there are several warnings: ld: warning: orphan section `.rela.iplt' from `arch/s390/kernel/head64.o' being placed in section `.rela.dyn' ld: warning: orphan section `.rela.head.text' from `arch/s390/kernel/head64.o' being placed in section `.rela.dyn' ld: warning: orphan section `.rela.init.text' from `arch/s390/kernel/head64.o' being placed in section `.rela.dyn' ld: warning: orphan section `.rela.rodata.cst8' from `arch/s390/kernel/head64.o' being placed in section `.rela.dyn' Orphan sections are sections that exist in an object file but don't have a corresponding output section in the final executable. ld raises a warning when it identifies such sections. Eliminate the warning by placing all .rela orphan sections in .rela.dyn and raise an error when size of .rela.dyn is greater than zero. i.e. Dont just neglect orphan sections. This is similar to adjustment performed in x86, where kernel is built with -fno-PIE. commit 5354e84598f2 ("x86/build: Add asserts for unwanted sections") [sumanthk@linux.ibm.com: rebased Josh Poimboeuf patches and move vmlinux.relocs to safe location] [hca@linux.ibm.com: merged compile warning fix from Sumanth] Tested-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Acked-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org> Signed-off-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Link: https://lore.kernel.org/r/20240219132734.22881-4-sumanthk@linux.ibm.com Link: https://lore.kernel.org/r/20240219132734.22881-5-sumanthk@linux.ibm.com Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/vdso64: filter out munaligned-symbols flag for vdsoSumanth Korikkar2024-02-201-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Gcc recently implemented an optimization [1] for loading symbols without explicit alignment, aligning with the IBM Z ELF ABI. This ABI mandates symbols to reside on a 2-byte boundary, enabling the use of the larl instruction. However, kernel linker scripts may still generate unaligned symbols. To address this, a new -munaligned-symbols option has been introduced [2] in recent gcc versions. [1] https://gcc.gnu.org/pipermail/gcc-patches/2023-June/622872.html [2] https://gcc.gnu.org/pipermail/gcc-patches/2023-August/625986.html However, when -munaligned-symbols is used in vdso code, it leads to the following compilation error: `.data.rel.ro.local' referenced in section `.text' of arch/s390/kernel/vdso64/vdso64_generic.o: defined in discarded section `.data.rel.ro.local' of arch/s390/kernel/vdso64/vdso64_generic.o vdso linker script discards .data section to make it lightweight. However, -munaligned-symbols in vdso object files references literal pool and accesses _vdso_data. Hence, compile vdso code without -munaligned-symbols. This means in the future, vdso code should deal with alignment of newly introduced unaligned linker symbols. Acked-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Link: https://lore.kernel.org/r/20240219132734.22881-2-sumanthk@linux.ibm.com Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/pai: simplify event start function for perf statThomas Richter2024-02-202-15/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When an event is started, read the current value of the PAI counter. This value is saved in event::hw.prev_count. When an event is stopped, this value is subtracted from the current value read out at event stop time. The difference is the delta of this counter. Simplify the logic and read the event value every time the event is started. This scheme is identical to other device drivers. Signed-off-by: Thomas Richter <tmricht@linux.ibm.com> Acked-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/pai: save PAI counter value page in event structureThomas Richter2024-02-202-16/+59
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When the PAI events ALL_CRYPTO or ALL_NNPA are created for system wide sampling, all PAI counters are monitored. On each process schedule out, the values of all PAI counters are investigated. Non-zero values are saved in the event's ring buffer as raw data. This scheme expects the start value of each counter to be reset to zero after each read operation performed by the PAI PMU device driver. This allows for only one active event at any one time as it relies on the start value of counters to be reset to zero. Create a save area for each installed PAI XXXX_ALL event and save all PAI counter values in this save area. Instead of clearing the PAI counter lowcore area to zero after each read operation, copy them from the lowcore area to the event's save area at process schedule out time. The delta of each PAI counter is calculated by subtracting the old counter's value stored in the event's save area from the current value stored in the lowcore area. With this scheme, mulitple events of the PAI counters XXXX_ALL can be handled at the same time. This will be addressed in a follow-on patch. Signed-off-by: Thomas Richter <tmricht@linux.ibm.com> Acked-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/sysinfo: convert bogomips calculation to CHeiko Carstens2024-02-161-15/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Provide several one instruction fpu inline assemebles and use them to implement the bogomips calculation in C like style. This is more for illustration purposes on how kernel fpu code can be written in C. This has the advantage that the author only has to take care of the floating point instructions, but doesn't need to take care of general purpose register allocation (if needed), and the semantics of all other instructions not related to fpu. Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/checksum: provide and use cksm() inline assemblyHeiko Carstens2024-02-162-5/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | Convert those callers of csum_partial() to use the cksm instruction, which are either very early or in critical paths, like panic/dump, so they don't have to rely on a working kernel infrastructure, which will be introduced with a subsequent patch. Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/fpu: limit save and restore to used registersHeiko Carstens2024-02-161-35/+77
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The first invocation of kernel_fpu_begin() after switching from user to kernel context will save all vector registers, even if only parts of the vector registers are used within the kernel fpu context. Given that save and restore of all vector registers is quite expensive change the current approach in several ways: - Instead of saving and restoring all user registers limit this to those registers which are actually used within an kernel fpu context. - On context switch save all remaining user fpu registers, so they can be restored when the task is rescheduled. - Saving user registers within kernel_fpu_begin() is done without disabling and enabling interrupts - which also slightly reduces runtime. In worst case (e.g. interrupt context uses the same registers) this may lead to the situation that registers are saved several times, however the assumption is that this will not happen frequently, so that the new method is faster in nearly all cases. - save_user_fpu_regs() can still be called from all contexts and saves all (or all remaining) user registers to a tasks ufpu user fpu save area. Overall this reduces the time required to save and restore the user fpu context for nearly all cases. Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/fpu: decrease stack usage for some casesHeiko Carstens2024-02-162-25/+25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The kernel_fpu structure has a quite large size of 520 bytes. In order to reduce stack footprint introduce several kernel fpu structures with different and also smaller sizes. This way every kernel fpu user must use the correct variant. A compile time check verifies that the correct variant is used. There are several users which use only 16 instead of all 32 vector registers. For those users the new kernel_fpu_16 structure with a size of only 266 bytes can be used. Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/fpu: remove anonymous union from struct fpuHeiko Carstens2024-02-163-56/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The anonymous union within struct fpu contains a floating point register array and a vector register array. Given that the vector register is always present remove the floating point register array. For configurations without vector registers save the floating point register contents within their corresponding vector register location. This allows to remove the union, and also to simplify ptrace and perf code. Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/fpu: remove regs member from struct fpuHeiko Carstens2024-02-162-8/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | KVM was the only user which modified the regs pointer in struct fpu. Remove the pointer and convert the rest of the core fpu code to directly access the save area embedded within struct fpu. Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/kvm: convert to regular kernel fpu userHeiko Carstens2024-02-161-2/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | KVM modifies the kernel fpu's regs pointer to its own area to implement its custom version of preemtible kernel fpu context. With general support for preemptible kernel fpu context there is no need for the extra complexity in KVM code anymore. Therefore convert KVM to a regular kernel fpu user. In particular this means that all TIF_FPU checks can be removed, since the fpu register context will never be changed by other kernel fpu users, and also the fpu register context will be restored if a thread is preempted. Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/fpu: make kernel fpu context preemptibleHeiko Carstens2024-02-161-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | Make the kernel fpu context preemptible. Add another fpu structure to the thread_struct, and use it to save and restore the kernel fpu context if its task uses fpu registers when it is preempted. Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/fpu: change type of fpu mask from u32 to intHeiko Carstens2024-02-161-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | Change type of fpu mask consistently from u32 to int. This is a prerequisite to make the kernel fpu usage preemptible. Upcoming code uses __atomic* ops which work with int pointers. Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/fpu: rename save_fpu_regs() to save_user_fpu_regs(), etcHeiko Carstens2024-02-167-79/+79
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Rename save_fpu_regs(), load_fpu_regs(), and struct thread_struct's fpu member to save_user_fpu_regs(), load_user_fpu_regs(), and ufpu. This way the function and variable names reflect for which context they are supposed to be used. This large and trivial conversion is a prerequisite for making the kernel fpu usage preemptible. Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/fpu: convert FPU CIF flag to regular TIF flagHeiko Carstens2024-02-163-10/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The FPU state, as represented by the CIF_FPU flag reflects the FPU state of a task, not the CPU it is running on. Therefore convert the flag to a regular TIF flag. This removes the magic in switch_to() where a save_fpu_regs() call for the currently (previous) running task sets the per-cpu CIF_FPU flag, which is required to restore FPU register contents of the next task, when it returns to user space. Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/fpu: convert __kernel_fpu_begin()/__kernel_fpu_end() to CHeiko Carstens2024-02-161-86/+62
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Convert the rather large __kernel_fpu_begin()/__kernel_fpu_end() inline assemblies to C. The C variant is much more readable, and this also allows to get rid of the non-obvious usage of KERNEL_VXR_* constants within the inline assemblies. E.g. "tmll %[m],6" correlates with the two bits set in KERNEL_VXR_LOW. If the corresponding defines would be changed, the inline assembles would break in a subtle way. Therefore convert to C, use the proper defines, and allow the compiler to generate code using the (hopefully) most efficient instructions. Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/fpu: provide and use vlm and vstm inline assembliesHeiko Carstens2024-02-161-18/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Instead of open-coding vlm and vstm inline assemblies at several locations, provide an fpu_* function for each instruction, and use them in the new save_vx_regs() and load_vx_regs() helper functions. Note that "O" and "R" inline assembly operand modifiers are used in order to pass the displacement and base register of the memory operands to the existing VLM and VSTM macros. The two operand modifiers are not available for clang. Therefore provide two variants of each inline assembly. The clang variant always uses and clobbers general purpose register 1, like in the previous inline assemblies, so it can be used as base register with a zero displacement. This generates slightly less efficient code, but can be removed as soon as clang has support for the used operand modifiers. Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/fpu: provide and use lfpc, sfpc, and stfpc inline assembliesHeiko Carstens2024-02-162-10/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | Instead of open-coding lfpc, sfpc, and stfpc inline assemblies at several locations, provide an fpu_* function for each instruction and use the function instead. Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/fpu: provide and use ld and std inline assembliesHeiko Carstens2024-02-161-72/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | Deduplicate the 64 ld and std inline assemblies. Provide an fpu inline assembly for both instructions, and use them in the new save_fp_regs() and load_fp_regs() helper functions. Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/fpu: use lfpc instead of sfpc instructionHeiko Carstens2024-02-161-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The only user of sfpc_safe() needs to read the new fpc register value from memory before it is set with sfpc. Avoid this indirection and use lfpc, which reads the new value from memory. Also add the "fpu_" prefix to have a common name space for fpu related inline assemblies, and provide memory access instrumentation. Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/fpu: move, rename, and merge header filesHeiko Carstens2024-02-1613-14/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Move, rename, and merge the fpu and vx header files. This way fpu header files have a consistent naming scheme (fpu*.h). Also get rid of the fpu subdirectory and move header files to asm directory, so that all fpu and vx header files can be found at the same location. Merge internal.h header file into other header files, since the internal helpers are used at many locations. so those helper functions are really not internal. Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/fpu: various coding style changesHeiko Carstens2024-02-161-11/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | Address various checkpatch warnings, adjust whitespace, and try to increase readability. This is just preparation, in order to avoid that subsequent patches contain any distracting drive-by coding style changes. Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/fpu: use KERNEL_VXR_LOW instead of KERNEL_VXR_V0V7Heiko Carstens2024-02-161-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Use KERNEL_VXR_LOW instead of KERNEL_VXR_V0V7 for configurations without vector registers in order to decide if floating point registers need to be saved and restored. Kernel FPU areas which use floating point registers are supposed to use the KERNEL_FPR mask, however users may also open-code this and specify KERNEL_VXR_V0V7 and/or KERNEL_VXR_V8V15. If only KERNEL_VXR_V8V15 is specified floating point registers wouldn't be saved and restored. Improve this and check for both bits. There are currently no users where this would fix a bug. Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/nmi: remove register validation codeHeiko Carstens2024-02-162-122/+47
| | | | | | | | | | | | | | | | | | | | | | | | | | | Remove the historic machine check handler code which validates registers. Registers are automatically validated as part of the machine check handling sequence (see Principles of Operation, Machine-Check Handling chapter, Validation). Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/setup: fix virtual vs physical address confusionGerald Schaefer2024-02-161-6/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix virtual vs physical address confusion. This does not fix a bug since virtual and physical address spaces are currently the same. /proc/iomem should report the physical address ranges, so use __pa_symbol() for resource registration, similar to other architectures. Signed-off-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/vdso: remove unused ENTRY in linker scriptsHeiko Carstens2024-02-142-2/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When linking vdso64.so.dbg with ld.lld, there is a warning about not finding _start for the starting address: ld.lld: warning: cannot find entry symbol _start; not setting start address Fix this by removing the unused ENTRY in both vdso linker scripts. See commit e247172854a5 ("powerpc/vdso: Remove unused ENTRY in linker scripts"), which solved the same problem for powerpc, for further details. Reviewed-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390: vmlinux.lds.S: explicitly keep various sectionsNathan Chancellor2024-02-141-0/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When building with CONFIG_LD_ORPHAN_WARN after selecting CONFIG_ARCH_HAS_LD_ORPHAN_WARN, there are some warnings around certain ELF sections: s390-linux-ld: warning: orphan section `.dynstr' from `arch/s390/kernel/head64.o' being placed in section `.dynstr' s390-linux-ld: warning: orphan section `.dynamic' from `arch/s390/kernel/head64.o' being placed in section `.dynamic' s390-linux-ld: warning: orphan section `.hash' from `arch/s390/kernel/head64.o' being placed in section `.hash' s390-linux-ld: warning: orphan section `.gnu.hash' from `arch/s390/kernel/head64.o' being placed in section `.gnu.hash' Explicitly keep those sections like other architectures when CONFIG_RELOCATABLE is enabled, which is always true for s390. [hca@linux.ibm.com: keep sections instead of discarding] Signed-off-by: Nathan Chancellor <nathan@kernel.org> Link: https://lore.kernel.org/r/20240207-s390-lld-and-orphan-warn-v1-4-8a665b3346ab@kernel.org Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390: vmlinux.lds.S: explicitly handle '.got' and '.plt' sectionsNathan Chancellor2024-02-141-0/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When building with CONFIG_LD_ORPHAN_WARN after selecting CONFIG_ARCH_HAS_LD_ORPHAN_WARN, there are a lot of warnings around the GOT and PLT sections: s390-linux-ld: warning: orphan section `.plt' from `arch/s390/kernel/head64.o' being placed in section `.plt' s390-linux-ld: warning: orphan section `.got' from `arch/s390/kernel/head64.o' being placed in section `.got' s390-linux-ld: warning: orphan section `.got.plt' from `arch/s390/kernel/head64.o' being placed in section `.got.plt' s390-linux-ld: warning: orphan section `.iplt' from `arch/s390/kernel/head64.o' being placed in section `.iplt' s390-linux-ld: warning: orphan section `.igot.plt' from `arch/s390/kernel/head64.o' being placed in section `.igot.plt' s390-linux-ld: warning: orphan section `.iplt' from `arch/s390/boot/head.o' being placed in section `.iplt' s390-linux-ld: warning: orphan section `.igot.plt' from `arch/s390/boot/head.o' being placed in section `.igot.plt' s390-linux-ld: warning: orphan section `.got' from `arch/s390/boot/head.o' being placed in section `.got' Currently, only the '.got' section is actually emitted in the final binary. In a manner similar to other architectures, put the '.got' section near the '.data' section and coalesce the PLT sections, checking that the final section is zero sized, which is a safe/tested approach versus full discard. Signed-off-by: Nathan Chancellor <nathan@kernel.org> Tested-by: Justin Stitt <justinstitt@google.com> Link: https://lore.kernel.org/r/20240207-s390-lld-and-orphan-warn-v1-3-8a665b3346ab@kernel.org Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390: vmlinux.lds.S: handle '.data.rel' sections explicitlyNathan Chancellor2024-02-141-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When building with CONFIG_LD_ORPHAN_WARN after selecting CONFIG_ARCH_HAS_LD_ORPHAN_WARN, there are a lot of warnings around '.data.rel' sections: s390-linux-ld: warning: orphan section `.data.rel' from `kernel/sched/build_utility.o' being placed in section `.data.rel' s390-linux-ld: warning: orphan section `.data.rel.local' from `kernel/sched/build_utility.o' being placed in section `.data.rel.local' s390-linux-ld: warning: orphan section `.data.rel.ro' from `kernel/sched/build_utility.o' being placed in section `.data.rel.ro' s390-linux-ld: warning: orphan section `.data.rel.ro.local' from `kernel/sched/build_utility.o' being placed in section `.data.rel.ro.local' Describe these in vmlinux.lds.S so there is no more warning and the sections are placed consistently between linkers. Signed-off-by: Nathan Chancellor <nathan@kernel.org> Tested-by: Justin Stitt <justinstitt@google.com> Link: https://lore.kernel.org/r/20240207-s390-lld-and-orphan-warn-v1-2-8a665b3346ab@kernel.org Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/switch_to: use generic header fileHeiko Carstens2024-02-127-10/+30
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Move the switch_to() implementation to process.c and use the generic switch_to.h header file instead, like some other architectures. This addresses also the oddity that the old switch_to() implementation assigns the return value of __switch_to() to 'prev' instead of 'last', like it should. Remove also all includes of switch_to.h from C files, except process.c. Acked-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/acrs: cleanup access register handlingHeiko Carstens2024-02-125-4/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | save_access_regs() and restore_access_regs() are only available by including switch_to.h. This is done by a couple of C files, which have nothing to do with switch_to(), but only need these functions. Move both functions to a new header file and improve the implementation: - Get rid of typedef - Add memory access instrumentation support - Use long displacement instructions lamy/stamy instead of lam/stam - all current users end up with better code because of this Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/fpu: make use of __uninitialized macroHeiko Carstens2024-02-091-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Code sections in s390 specific kernel code which use floating point or vector registers all come with a 520 byte stack variable to save already in use registers, if required. With INIT_STACK_ALL_PATTERN or INIT_STACK_ALL_ZERO enabled this variable will always be initialized on function entry in addition to saving register contents, which contradicts the intention (performance improvement) of such code sections. Therefore provide a DECLARE_KERNEL_FPU_ONSTACK() macro which provides struct kernel_fpu variables with an __uninitialized attribute, and convert all existing code to use this. This way only this specific type of stack variable will not be initialized, regardless of config options. Reviewed-by: Nathan Chancellor <nathan@kernel.org> Reviewed-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20240205154844.3757121-3-hca@linux.ibm.com Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/time: make stp_subsys constRicardo B. Marliere2024-02-091-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now that the driver core can properly handle constant struct bus_type, move the stp_subsys variable to be a constant structure as well, placing it into read-only memory which can not be modified at runtime. Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: "Ricardo B. Marliere" <ricardo@marliere.net> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Link: https://lore.kernel.org/r/20240204-bus_cleanup-s390_time-v1-1-d2120156982a@marliere.net Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/vdso: drop '-fPIC' from LDFLAGSNathan Chancellor2024-02-092-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | '-fPIC' as an option to the linker does not do what it seems like it should. With ld.bfd, it is treated as '-f PIC', which does not make sense based on the meaning of '-f': -f SHLIB, --auxiliary SHLIB Auxiliary filter for shared object symbol table When building with ld.lld (currently under review in a GitHub pull request), it just errors out because '-f' means nothing and neither does '-fPIC': ld.lld: error: unknown argument '-fPIC' '-fPIC' was blindly copied from CFLAGS when the vDSO stopped being linked with '$(CC)', it should not be needed. Remove it to clear up the build failure with ld.lld. Fixes: 2b2a25845d53 ("s390/vdso: Use $(LD) instead of $(CC) to link vDSO") Link: https://github.com/llvm/llvm-project/pull/75643 Signed-off-by: Nathan Chancellor <nathan@kernel.org> Reviewed-by: Fangrui Song <maskray@google.com> Link: https://lore.kernel.org/r/20240130-s390-vdso-drop-fpic-from-ldflags-v1-1-094ad104fc55@kernel.org Signed-off-by: Heiko Carstens <hca@linux.ibm.com>