aboutsummaryrefslogtreecommitdiff
path: root/arch/arm64/kernel
AgeCommit message (Collapse)AuthorFilesLines
2024-07-09arm64: add 'runtime constant' supportruntime-constantsLinus Torvalds1-0/+3
This implements the runtime constant infrastructure for arm64, allowing the dcache d_hash() function to be generated using as a constant for hash table address followed by shift by a constant of the hash index. [ Fixed up to deal with the big-endian case as per Mark Rutland ] Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2024-06-05arm64: armv8_deprecated: Fix warning in isndep cpuhp starting processWei Li1-0/+3
The function run_all_insn_set_hw_mode() is registered as startup callback of 'CPUHP_AP_ARM64_ISNDEP_STARTING', it invokes set_hw_mode() methods of all emulated instructions. As the STARTING callbacks are not expected to fail, if one of the set_hw_mode() fails, e.g. due to el0 mixed-endian is not supported for 'setend', it will report a warning: ``` CPU[2] cannot support the emulation of setend CPU 2 UP state arm64/isndep:starting (136) failed (-22) CPU2: Booted secondary processor 0x0000000002 [0x414fd0c1] ``` To fix it, add a check for INSN_UNAVAILABLE status and skip the process. Signed-off-by: Wei Li <liwei391@huawei.com> Tested-by: Huisong Li <lihuisong@huawei.com> Link: https://lore.kernel.org/r/20240423093501.3460764-1-liwei391@huawei.com Signed-off-by: Will Deacon <will@kernel.org>
2024-05-25Merge tag 'mm-hotfixes-stable-2024-05-25-09-13' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull misc fixes from Andrew Morton: "16 hotfixes, 11 of which are cc:stable. A few nilfs2 fixes, the remainder are for MM: a couple of selftests fixes, various singletons fixing various issues in various parts" * tag 'mm-hotfixes-stable-2024-05-25-09-13' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: mm/ksm: fix possible UAF of stable_node mm/memory-failure: fix handling of dissolved but not taken off from buddy pages mm: /proc/pid/smaps_rollup: avoid skipping vma after getting mmap_lock again nilfs2: fix potential hang in nilfs_detach_log_writer() nilfs2: fix unexpected freezing of nilfs_segctor_sync() nilfs2: fix use-after-free of timer for log writer thread selftests/mm: fix build warnings on ppc64 arm64: patching: fix handling of execmem addresses selftests/mm: compaction_test: fix bogus test success and reduce probability of OOM-killer invocation selftests/mm: compaction_test: fix incorrect write of zero to nr_hugepages selftests/mm: compaction_test: fix bogus test success on Aarch64 mailmap: update email address for Satya Priya mm/huge_memory: don't unpoison huge_zero_folio kasan, fortify: properly rename memintrinsics lib: add version into /proc/allocinfo output mm/vmalloc: fix vmalloc which may return null if called with __GFP_NOFAIL
2024-05-24arm64: patching: fix handling of execmem addressesWill Deacon1-1/+1
Klara Modin reported warnings for a kernel configured with BPF_JIT but without MODULES: [ 44.131296] Trying to vfree() bad address (000000004a17c299) [ 44.138024] WARNING: CPU: 1 PID: 193 at mm/vmalloc.c:3189 remove_vm_area (mm/vmalloc.c:3189 (discriminator 1)) [ 44.146675] CPU: 1 PID: 193 Comm: kworker/1:2 Tainted: G D W 6.9.0-01786-g2c9e5d4a0082 #25 [ 44.158229] Hardware name: Raspberry Pi 3 Model B (DT) [ 44.164433] Workqueue: events bpf_prog_free_deferred [ 44.170492] pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ 44.178601] pc : remove_vm_area (mm/vmalloc.c:3189 (discriminator 1)) [ 44.183705] lr : remove_vm_area (mm/vmalloc.c:3189 (discriminator 1)) [ 44.188772] sp : ffff800082a13c70 [ 44.193112] x29: ffff800082a13c70 x28: 0000000000000000 x27: 0000000000000000 [ 44.201384] x26: 0000000000000000 x25: ffff00003a44efa0 x24: 00000000d4202000 [ 44.209658] x23: ffff800081223dd0 x22: ffff00003a198a40 x21: ffff8000814dd880 [ 44.217924] x20: 00000000d4202000 x19: ffff8000814dd880 x18: 0000000000000006 [ 44.226206] x17: 0000000000000000 x16: 0000000000000020 x15: 0000000000000002 [ 44.234460] x14: ffff8000811a6370 x13: 0000000020000000 x12: 0000000000000000 [ 44.242710] x11: ffff8000811a6370 x10: 0000000000000144 x9 : ffff8000811fe370 [ 44.250959] x8 : 0000000000017fe8 x7 : 00000000fffff000 x6 : ffff8000811fe370 [ 44.259206] x5 : 0000000000000000 x4 : 0000000000000000 x3 : 0000000000000000 [ 44.267457] x2 : 0000000000000000 x1 : 0000000000000000 x0 : ffff000002203240 [ 44.275703] Call trace: [ 44.279158] remove_vm_area (mm/vmalloc.c:3189 (discriminator 1)) [ 44.283858] vfree (mm/vmalloc.c:3322) [ 44.287835] execmem_free (mm/execmem.c:70) [ 44.292347] bpf_jit_free_exec+0x10/0x1c [ 44.297283] bpf_prog_pack_free (kernel/bpf/core.c:1006) [ 44.302457] bpf_jit_binary_pack_free (kernel/bpf/core.c:1195) [ 44.307951] bpf_jit_free (include/linux/filter.h:1083 arch/arm64/net/bpf_jit_comp.c:2474) [ 44.312342] bpf_prog_free_deferred (kernel/bpf/core.c:2785) [ 44.317785] process_one_work (kernel/workqueue.c:3273) [ 44.322684] worker_thread (kernel/workqueue.c:3342 (discriminator 2) kernel/workqueue.c:3429 (discriminator 2)) [ 44.327292] kthread (kernel/kthread.c:388) [ 44.331342] ret_from_fork (arch/arm64/kernel/entry.S:861) The problem is because bpf_arch_text_copy() silently fails to write to the read-only area as a result of patch_map() faulting and the resulting -EFAULT being chucked away. Update patch_map() to use CONFIG_EXECMEM instead of CONFIG_STRICT_MODULE_RWX to check for vmalloc addresses. Link: https://lkml.kernel.org/r/20240521213813.703309-1-rppt@kernel.org Fixes: 2c9e5d4a0082 ("bpf: remove CONFIG_BPF_JIT dependency on CONFIG_MODULES of") Signed-off-by: Will Deacon <will@kernel.org> Signed-off-by: Mike Rapoport (IBM) <rppt@kernel.org> Reported-by: Klara Modin <klarasmodin@gmail.com> Closes: https://lore.kernel.org/all/7983fbbf-0127-457c-9394-8d6e4299c685@gmail.com Tested-by: Klara Modin <klarasmodin@gmail.com> Cc: Björn Töpel <bjorn@kernel.org> Cc: Luis Chamberlain <mcgrof@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-05-23Merge tag 'trace-assign-str-v6.10' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull tracing cleanup from Steven Rostedt: "Remove second argument of __assign_str() The __assign_str() macro logic of the TRACE_EVENT() macro was optimized so that it no longer needs the second argument. The __assign_str() is always matched with __string() field that takes a field name and the source for that field: __string(field, source) The TRACE_EVENT() macro logic will save off the source value and then use that value to copy into the ring buffer via the __assign_str(). Before commit c1fa617caeb0 ("tracing: Rework __assign_str() and __string() to not duplicate getting the string"), the __assign_str() needed the second argument which would perform the same logic as the __string() source parameter did. Not only would this add overhead, but it was error prone as if the __assign_str() source produced something different, it may not have allocated enough for the string in the ring buffer (as the __string() source was used to determine how much to allocate) Now that the __assign_str() just uses the same string that was used in __string() it no longer needs the source parameter. It can now be removed" * tag 'trace-assign-str-v6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: tracing/treewide: Remove second parameter of __assign_str()
2024-05-23Merge tag 'arm64-fixes' of ↵Linus Torvalds4-22/+61
git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull arm64 fixes from Will Deacon: "The major fix here is for a filesystem corruption issue reported on Apple M1 as a result of buggy management of the floating point register state introduced in 6.8. I initially reverted one of the offending patches, but in the end Ard cooked a proper fix so there's a revert+reapply in the series. Aside from that, we've got some CPU errata workarounds and misc other fixes. - Fix broken FP register state tracking which resulted in filesystem corruption when dm-crypt is used - Workarounds for Arm CPU errata affecting the SSBS Spectre mitigation - Fix lockdep assertion in DMC620 memory controller PMU driver - Fix alignment of BUG table when CONFIG_DEBUG_BUGVERBOSE is disabled" * tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: arm64/fpsimd: Avoid erroneous elide of user state reload Reapply "arm64: fpsimd: Implement lazy restore for kernel mode FPSIMD" arm64: asm-bug: Add .align 2 to the end of __BUG_ENTRY perf/arm-dmc620: Fix lockdep assert in ->event_init() Revert "arm64: fpsimd: Implement lazy restore for kernel mode FPSIMD" arm64: errata: Add workaround for Arm errata 3194386 and 3312417 arm64: cputype: Add Neoverse-V3 definitions arm64: cputype: Add Cortex-X4 definitions arm64: barrier: Restore spec_bar() macro
2024-05-22tracing/treewide: Remove second parameter of __assign_str()Steven Rostedt (Google)1-1/+1
With the rework of how the __string() handles dynamic strings where it saves off the source string in field in the helper structure[1], the assignment of that value to the trace event field is stored in the helper value and does not need to be passed in again. This means that with: __string(field, mystring) Which use to be assigned with __assign_str(field, mystring), no longer needs the second parameter and it is unused. With this, __assign_str() will now only get a single parameter. There's over 700 users of __assign_str() and because coccinelle does not handle the TRACE_EVENT() macro I ended up using the following sed script: git grep -l __assign_str | while read a ; do sed -e 's/\(__assign_str([^,]*[^ ,]\) *,[^;]*/\1)/' $a > /tmp/test-file; mv /tmp/test-file $a; done I then searched for __assign_str() that did not end with ';' as those were multi line assignments that the sed script above would fail to catch. Note, the same updates will need to be done for: __assign_str_len() __assign_rel_str() __assign_rel_str_len() I tested this with both an allmodconfig and an allyesconfig (build only for both). [1] https://lore.kernel.org/linux-trace-kernel/20240222211442.634192653@goodmis.org/ Link: https://lore.kernel.org/linux-trace-kernel/20240516133454.681ba6a0@rorschach.local.home Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Julia Lawall <Julia.Lawall@inria.fr> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Acked-by: Jani Nikula <jani.nikula@intel.com> Acked-by: Christian König <christian.koenig@amd.com> for the amdgpu parts. Acked-by: Thomas Hellström <thomas.hellstrom@linux.intel.com> #for Acked-by: Rafael J. Wysocki <rafael@kernel.org> # for thermal Acked-by: Takashi Iwai <tiwai@suse.de> Acked-by: Darrick J. Wong <djwong@kernel.org> # xfs Tested-by: Guenter Roeck <linux@roeck-us.net>
2024-05-22arm64/fpsimd: Avoid erroneous elide of user state reloadArd Biesheuvel1-22/+22
TIF_FOREIGN_FPSTATE is a 'convenience' flag that should reflect whether the current CPU holds the most recent user mode FP/SIMD state of the current task. It combines two conditions: - whether the current CPU's FP/SIMD state belongs to the task; - whether that state is the most recent associated with the task (as a task may have executed on other CPUs as well). When a task is scheduled in and TIF_KERNEL_FPSTATE is set, it means the task was in a kernel mode NEON section when it was scheduled out, and so the kernel mode FP/SIMD state is restored. Since this implies that the current CPU is *not* holding the most recent user mode FP/SIMD state of the current task, the TIF_FOREIGN_FPSTATE flag is set too, so that the user mode FP/SIMD state is reloaded from memory when returning to userland. However, the task may be scheduled out after completing the kernel mode NEON section, but before returning to userland. When this happens, the TIF_FOREIGN_FPSTATE flag will not be preserved, but will be set as usual the next time the task is scheduled in, and will be based on the above conditions. This means that, rather than setting TIF_FOREIGN_FPSTATE when scheduling in a task with TIF_KERNEL_FPSTATE set, the underlying state should be updated so that TIF_FOREIGN_FPSTATE will assume the expected value as a result. So instead, call fpsimd_flush_cpu_state(), which takes care of this. Closes: https://lore.kernel.org/all/cb8822182231850108fa43e0446a4c7f@kernel.org Reported-by: Johannes Nixdorf <mixi@shadowice.org> Fixes: aefbab8e77eb ("arm64: fpsimd: Preserve/restore kernel mode NEON at context switch") Cc: Mark Brown <broonie@kernel.org> Cc: Dave Martin <Dave.Martin@arm.com> Cc: Janne Grunau <j@jannau.net> Cc: stable@vger.kernel.org Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Tested-by: Janne Grunau <j@jannau.net> Tested-by: Johannes Nixdorf <mixi@shadowice.org> Reviewed-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20240522091335.335346-2-ardb+git@google.com Signed-off-by: Will Deacon <will@kernel.org>
2024-05-22Reapply "arm64: fpsimd: Implement lazy restore for kernel mode FPSIMD"Will Deacon1-0/+18
This reverts commit b8995a18417088bb53f87c49d200ec72a9dd4ec1. Ard managed to reproduce the dm-crypt corruption problem and got to the bottom of it, so re-apply the problematic patch in preparation for fixing things properly. Cc: stable@vger.kernel.org Signed-off-by: Will Deacon <will@kernel.org>
2024-05-19Merge tag 'mm-stable-2024-05-17-19-19' of ↵Linus Torvalds1-0/+1
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull mm updates from Andrew Morton: "The usual shower of singleton fixes and minor series all over MM, documented (hopefully adequately) in the respective changelogs. Notable series include: - Lucas Stach has provided some page-mapping cleanup/consolidation/ maintainability work in the series "mm/treewide: Remove pXd_huge() API". - In the series "Allow migrate on protnone reference with MPOL_PREFERRED_MANY policy", Donet Tom has optimized mempolicy's MPOL_PREFERRED_MANY mode, yielding almost doubled performance in one test. - In their series "Memory allocation profiling" Kent Overstreet and Suren Baghdasaryan have contributed a means of determining (via /proc/allocinfo) whereabouts in the kernel memory is being allocated: number of calls and amount of memory. - Matthew Wilcox has provided the series "Various significant MM patches" which does a number of rather unrelated things, but in largely similar code sites. - In his series "mm: page_alloc: freelist migratetype hygiene" Johannes Weiner has fixed the page allocator's handling of migratetype requests, with resulting improvements in compaction efficiency. - In the series "make the hugetlb migration strategy consistent" Baolin Wang has fixed a hugetlb migration issue, which should improve hugetlb allocation reliability. - Liu Shixin has hit an I/O meltdown caused by readahead in a memory-tight memcg. Addressed in the series "Fix I/O high when memory almost met memcg limit". - In the series "mm/filemap: optimize folio adding and splitting" Kairui Song has optimized pagecache insertion, yielding ~10% performance improvement in one test. - Baoquan He has cleaned up and consolidated the early zone initialization code in the series "mm/mm_init.c: refactor free_area_init_core()". - Baoquan has also redone some MM initializatio code in the series "mm/init: minor clean up and improvement". - MM helper cleanups from Christoph Hellwig in his series "remove follow_pfn". - More cleanups from Matthew Wilcox in the series "Various page->flags cleanups". - Vlastimil Babka has contributed maintainability improvements in the series "memcg_kmem hooks refactoring". - More folio conversions and cleanups in Matthew Wilcox's series: "Convert huge_zero_page to huge_zero_folio" "khugepaged folio conversions" "Remove page_idle and page_young wrappers" "Use folio APIs in procfs" "Clean up __folio_put()" "Some cleanups for memory-failure" "Remove page_mapping()" "More folio compat code removal" - David Hildenbrand chipped in with "fs/proc/task_mmu: convert hugetlb functions to work on folis". - Code consolidation and cleanup work related to GUP's handling of hugetlbs in Peter Xu's series "mm/gup: Unify hugetlb, part 2". - Rick Edgecombe has developed some fixes to stack guard gaps in the series "Cover a guard gap corner case". - Jinjiang Tu has fixed KSM's behaviour after a fork+exec in the series "mm/ksm: fix ksm exec support for prctl". - Baolin Wang has implemented NUMA balancing for multi-size THPs. This is a simple first-cut implementation for now. The series is "support multi-size THP numa balancing". - Cleanups to vma handling helper functions from Matthew Wilcox in the series "Unify vma_address and vma_pgoff_address". - Some selftests maintenance work from Dev Jain in the series "selftests/mm: mremap_test: Optimizations and style fixes". - Improvements to the swapping of multi-size THPs from Ryan Roberts in the series "Swap-out mTHP without splitting". - Kefeng Wang has significantly optimized the handling of arm64's permission page faults in the series "arch/mm/fault: accelerate pagefault when badaccess" "mm: remove arch's private VM_FAULT_BADMAP/BADACCESS" - GUP cleanups from David Hildenbrand in "mm/gup: consistently call it GUP-fast". - hugetlb fault code cleanups from Vishal Moola in "Hugetlb fault path to use struct vm_fault". - selftests build fixes from John Hubbard in the series "Fix selftests/mm build without requiring "make headers"". - Memory tiering fixes/improvements from Ho-Ren (Jack) Chuang in the series "Improved Memory Tier Creation for CPUless NUMA Nodes". Fixes the initialization code so that migration between different memory types works as intended. - David Hildenbrand has improved follow_pte() and fixed an errant driver in the series "mm: follow_pte() improvements and acrn follow_pte() fixes". - David also did some cleanup work on large folio mapcounts in his series "mm: mapcount for large folios + page_mapcount() cleanups". - Folio conversions in KSM in Alex Shi's series "transfer page to folio in KSM". - Barry Song has added some sysfs stats for monitoring multi-size THP's in the series "mm: add per-order mTHP alloc and swpout counters". - Some zswap cleanups from Yosry Ahmed in the series "zswap same-filled and limit checking cleanups". - Matthew Wilcox has been looking at buffer_head code and found the documentation to be lacking. The series is "Improve buffer head documentation". - Multi-size THPs get more work, this time from Lance Yang. His series "mm/madvise: enhance lazyfreeing with mTHP in madvise_free" optimizes the freeing of these things. - Kemeng Shi has added more userspace-visible writeback instrumentation in the series "Improve visibility of writeback". - Kemeng Shi then sent some maintenance work on top in the series "Fix and cleanups to page-writeback". - Matthew Wilcox reduces mmap_lock traffic in the anon vma code in the series "Improve anon_vma scalability for anon VMAs". Intel's test bot reported an improbable 3x improvement in one test. - SeongJae Park adds some DAMON feature work in the series "mm/damon: add a DAMOS filter type for page granularity access recheck" "selftests/damon: add DAMOS quota goal test" - Also some maintenance work in the series "mm/damon/paddr: simplify page level access re-check for pageout" "mm/damon: misc fixes and improvements" - David Hildenbrand has disabled some known-to-fail selftests ni the series "selftests: mm: cow: flag vmsplice() hugetlb tests as XFAIL". - memcg metadata storage optimizations from Shakeel Butt in "memcg: reduce memory consumption by memcg stats". - DAX fixes and maintenance work from Vishal Verma in the series "dax/bus.c: Fixups for dax-bus locking"" * tag 'mm-stable-2024-05-17-19-19' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (426 commits) memcg, oom: cleanup unused memcg_oom_gfp_mask and memcg_oom_order selftests/mm: hugetlb_madv_vs_map: avoid test skipping by querying hugepage size at runtime mm/hugetlb: add missing VM_FAULT_SET_HINDEX in hugetlb_wp mm/hugetlb: add missing VM_FAULT_SET_HINDEX in hugetlb_fault selftests: cgroup: add tests to verify the zswap writeback path mm: memcg: make alloc_mem_cgroup_per_node_info() return bool mm/damon/core: fix return value from damos_wmark_metric_value mm: do not update memcg stats for NR_{FILE/SHMEM}_PMDMAPPED selftests: cgroup: remove redundant enabling of memory controller Docs/mm/damon/maintainer-profile: allow posting patches based on damon/next tree Docs/mm/damon/maintainer-profile: change the maintainer's timezone from PST to PT Docs/mm/damon/design: use a list for supported filters Docs/admin-guide/mm/damon/usage: fix wrong schemes effective quota update command Docs/admin-guide/mm/damon/usage: fix wrong example of DAMOS filter matching sysfs file selftests/damon: classify tests for functionalities and regressions selftests/damon/_damon_sysfs: use 'is' instead of '==' for 'None' selftests/damon/_damon_sysfs: find sysfs mount point from /proc/mounts selftests/damon/_damon_sysfs: check errors from nr_schemes file reads mm/damon/core: initialize ->esz_bp from damos_quota_init_priv() selftests/damon: add a test for DAMOS quota goal ...
2024-05-18Merge tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdmaLinus Torvalds1-0/+42
Pull rdma updates from Jason Gunthorpe: "Aside from the usual things this has an arch update for __iowrite64_copy() used by the RDMA drivers. This API was intended to generate large 64 byte MemWr TLPs on PCI. These days most processors had done this by just repeating writel() in a loop. S390 and some new ARM64 designs require a special helper to get this to generate. - Small improvements and fixes for erdma, efa, hfi1, bnxt_re - Fix a UAF crash after module unload on leaking restrack entry - Continue adding full RDMA support in mana with support for EQs, GID's and CQs - Improvements to the mkey cache in mlx5 - DSCP traffic class support in hns and several bug fixes - Cap the maximum number of MADs in the receive queue to avoid OOM - Another batch of rxe bug fixes from large scale testing - __iowrite64_copy() optimizations for write combining MMIO memory - Remove NULL checks before dev_put/hold() - EFA support for receive with immediate - Fix a recent memleaking regression in a cma error path" * tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma: (70 commits) RDMA/cma: Fix kmemleak in rdma_core observed during blktests nvme/rdma use siw RDMA/IPoIB: Fix format truncation compilation errors bnxt_re: avoid shift undefined behavior in bnxt_qplib_alloc_init_hwq RDMA/efa: Support QP with unsolicited write w/ imm. receive IB/hfi1: Remove generic .ndo_get_stats64 IB/hfi1: Do not use custom stat allocator RDMA/hfi1: Use RMW accessors for changing LNKCTL2 RDMA/mana_ib: implement uapi for creation of rnic cq RDMA/mana_ib: boundary check before installing cq callbacks RDMA/mana_ib: introduce a helper to remove cq callbacks RDMA/mana_ib: create and destroy RNIC cqs RDMA/mana_ib: create EQs for RNIC CQs RDMA/core: Remove NULL check before dev_{put, hold} RDMA/ipoib: Remove NULL check before dev_{put, hold} RDMA/mlx5: Remove NULL check before dev_{put, hold} RDMA/mlx5: Track DCT, DCI and REG_UMR QPs as diver_detail resources. RDMA/core: Add an option to display driver-specific QPs in the rdmatool RDMA/efa: Add shutdown notifier RDMA/mana_ib: Fix missing ret value IB/mlx5: Use __iowrite64_copy() for write combining stores ...
2024-05-18Merge tag 'kbuild-v6.10' of ↵Linus Torvalds3-16/+2
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull Kbuild updates from Masahiro Yamada: - Avoid 'constexpr', which is a keyword in C23 - Allow 'dtbs_check' and 'dt_compatible_check' run independently of 'dt_binding_check' - Fix weak references to avoid GOT entries in position-independent code generation - Convert the last use of 'optional' property in arch/sh/Kconfig - Remove support for the 'optional' property in Kconfig - Remove support for Clang's ThinLTO caching, which does not work with the .incbin directive - Change the semantics of $(src) so it always points to the source directory, which fixes Makefile inconsistencies between upstream and downstream - Fix 'make tar-pkg' for RISC-V to produce a consistent package - Provide reasonable default coverage for objtool, sanitizers, and profilers - Remove redundant OBJECT_FILES_NON_STANDARD, KASAN_SANITIZE, etc. - Remove the last use of tristate choice in drivers/rapidio/Kconfig - Various cleanups and fixes in Kconfig * tag 'kbuild-v6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (46 commits) kconfig: use sym_get_choice_menu() in sym_check_prop() rapidio: remove choice for enumeration kconfig: lxdialog: remove initialization with A_NORMAL kconfig: m/nconf: merge two item_add_str() calls kconfig: m/nconf: remove dead code to display value of bool choice kconfig: m/nconf: remove dead code to display children of choice members kconfig: gconf: show checkbox for choice correctly kbuild: use GCOV_PROFILE and KCSAN_SANITIZE in scripts/Makefile.modfinal Makefile: remove redundant tool coverage variables kbuild: provide reasonable defaults for tool coverage modules: Drop the .export_symbol section from the final modules kconfig: use menu_list_for_each_sym() in sym_check_choice_deps() kconfig: use sym_get_choice_menu() in conf_write_defconfig() kconfig: add sym_get_choice_menu() helper kconfig: turn defaults and additional prompt for choice members into error kconfig: turn missing prompt for choice members into error kconfig: turn conf_choice() into void function kconfig: use linked list in sym_set_changed() kconfig: gconf: use MENU_CHANGED instead of SYMBOL_CHANGED kconfig: gconf: remove debug code ...
2024-05-17Revert "arm64: fpsimd: Implement lazy restore for kernel mode FPSIMD"Will Deacon1-18/+0
This reverts commit 2632e25217696712681dd1f3ecc0d71624ea3b23. Johannes (and others) report data corruption with dm-crypt on Apple M1 which has been bisected to this change. Revert the offending commit while we figure out what's going on. Cc: stable@vger.kernel.org Reported-by: Johannes Nixdorf <mixi@shadowice.org> Link: https://lore.kernel.org/all/D1B7GPIR9K1E.5JFV37G0YTIF@shadowice.org/ Signed-off-by: Will Deacon <will@kernel.org>
2024-05-15Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds1-2/+2
Pull KVM updates from Paolo Bonzini: "ARM: - Move a lot of state that was previously stored on a per vcpu basis into a per-CPU area, because it is only pertinent to the host while the vcpu is loaded. This results in better state tracking, and a smaller vcpu structure. - Add full handling of the ERET/ERETAA/ERETAB instructions in nested virtualisation. The last two instructions also require emulating part of the pointer authentication extension. As a result, the trap handling of pointer authentication has been greatly simplified. - Turn the global (and not very scalable) LPI translation cache into a per-ITS, scalable cache, making non directly injected LPIs much cheaper to make visible to the vcpu. - A batch of pKVM patches, mostly fixes and cleanups, as the upstreaming process seems to be resuming. Fingers crossed! - Allocate PPIs and SGIs outside of the vcpu structure, allowing for smaller EL2 mapping and some flexibility in implementing more or less than 32 private IRQs. - Purge stale mpidr_data if a vcpu is created after the MPIDR map has been created. - Preserve vcpu-specific ID registers across a vcpu reset. - Various minor cleanups and improvements. LoongArch: - Add ParaVirt IPI support - Add software breakpoint support - Add mmio trace events support RISC-V: - Support guest breakpoints using ebreak - Introduce per-VCPU mp_state_lock and reset_cntx_lock - Virtualize SBI PMU snapshot and counter overflow interrupts - New selftests for SBI PMU and Guest ebreak - Some preparatory work for both TDX and SNP page fault handling. This also cleans up the page fault path, so that the priorities of various kinds of fauls (private page, no memory, write to read-only slot, etc.) are easier to follow. x86: - Minimize amount of time that shadow PTEs remain in the special REMOVED_SPTE state. This is a state where the mmu_lock is held for reading but concurrent accesses to the PTE have to spin; shortening its use allows other vCPUs to repopulate the zapped region while the zapper finishes tearing down the old, defunct page tables. - Advertise the max mappable GPA in the "guest MAXPHYADDR" CPUID field, which is defined by hardware but left for software use. This lets KVM communicate its inability to map GPAs that set bits 51:48 on hosts without 5-level nested page tables. Guest firmware is expected to use the information when mapping BARs; this avoids that they end up at a legal, but unmappable, GPA. - Fixed a bug where KVM would not reject accesses to MSR that aren't supposed to exist given the vCPU model and/or KVM configuration. - As usual, a bunch of code cleanups. x86 (AMD): - Implement a new and improved API to initialize SEV and SEV-ES VMs, which will also be extendable to SEV-SNP. The new API specifies the desired encryption in KVM_CREATE_VM and then separately initializes the VM. The new API also allows customizing the desired set of VMSA features; the features affect the measurement of the VM's initial state, and therefore enabling them cannot be done tout court by the hypervisor. While at it, the new API includes two bugfixes that couldn't be applied to the old one without a flag day in userspace or without affecting the initial measurement. When a SEV-ES VM is created with the new VM type, KVM_GET_REGS/KVM_SET_REGS and friends are rejected once the VMSA has been encrypted. Also, the FPU and AVX state will be synchronized and encrypted too. - Support for GHCB version 2 as applicable to SEV-ES guests. This, once more, is only accessible when using the new KVM_SEV_INIT2 flow for initialization of SEV-ES VMs. x86 (Intel): - An initial bunch of prerequisite patches for Intel TDX were merged. They generally don't do anything interesting. The only somewhat user visible change is a new debugging mode that checks that KVM's MMU never triggers a #VE virtualization exception in the guest. - Clear vmcs.EXIT_QUALIFICATION when synthesizing an EPT Misconfig VM-Exit to L1, as per the SDM. Generic: - Use vfree() instead of kvfree() for allocations that always use vcalloc() or __vcalloc(). - Remove .change_pte() MMU notifier - the changes to non-KVM code are small and Andrew Morton asked that I also take those through the KVM tree. The callback was only ever implemented by KVM (which was also the original user of MMU notifiers) but it had been nonfunctional ever since calls to set_pte_at_notify were wrapped with invalidate_range_start and invalidate_range_end... in 2012. Selftests: - Enhance the demand paging test to allow for better reporting and stressing of UFFD performance. - Convert the steal time test to generate TAP-friendly output. - Fix a flaky false positive in the xen_shinfo_test due to comparing elapsed time across two different clock domains. - Skip the MONITOR/MWAIT test if the host doesn't actually support MWAIT. - Avoid unnecessary use of "sudo" in the NX hugepage test wrapper shell script, to play nice with running in a minimal userspace environment. - Allow skipping the RSEQ test's sanity check that the vCPU was able to complete a reasonable number of KVM_RUNs, as the assert can fail on a completely valid setup. If the test is run on a large-ish system that is otherwise idle, and the test isn't affined to a low-ish number of CPUs, the vCPU task can be repeatedly migrated to CPUs that are in deep sleep states, which results in the vCPU having very little net runtime before the next migration due to high wakeup latencies. - Define _GNU_SOURCE for all selftests to fix a warning that was introduced by a change to kselftest_harness.h late in the 6.9 cycle, and because forcing every test to #define _GNU_SOURCE is painful. - Provide a global pseudo-RNG instance for all tests, so that library code can generate random, but determinstic numbers. - Use the global pRNG to randomly force emulation of select writes from guest code on x86, e.g. to help validate KVM's emulation of locked accesses. - Allocate and initialize x86's GDT, IDT, TSS, segments, and default exception handlers at VM creation, instead of forcing tests to manually trigger the related setup. Documentation: - Fix a goof in the KVM_CREATE_GUEST_MEMFD documentation" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (225 commits) selftests/kvm: remove dead file KVM: selftests: arm64: Test vCPU-scoped feature ID registers KVM: selftests: arm64: Test that feature ID regs survive a reset KVM: selftests: arm64: Store expected register value in set_id_regs KVM: selftests: arm64: Rename helper in set_id_regs to imply VM scope KVM: arm64: Only reset vCPU-scoped feature ID regs once KVM: arm64: Reset VM feature ID regs from kvm_reset_sys_regs() KVM: arm64: Rename is_id_reg() to imply VM scope KVM: arm64: Destroy mpidr_data for 'late' vCPU creation KVM: arm64: Use hVHE in pKVM by default on CPUs with VHE support KVM: arm64: Fix hvhe/nvhe early alias parsing KVM: SEV: Allow per-guest configuration of GHCB protocol version KVM: SEV: Add GHCB handling for termination requests KVM: SEV: Add GHCB handling for Hypervisor Feature Support requests KVM: SEV: Add support to handle AP reset MSR protocol KVM: x86: Explicitly zero kvm_caps during vendor module load KVM: x86: Fully re-initialize supported_mce_cap on vendor module load KVM: x86: Fully re-initialize supported_vm_types on vendor module load KVM: x86/mmu: Sanity check that __kvm_faultin_pfn() doesn't create noslot pfns KVM: x86/mmu: Initialize kvm_page_fault's pfn and hva to error values ...
2024-05-15Merge tag 'modules-6.10-rc1' of ↵Linus Torvalds2-133/+0
git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux Pull modules updates from Luis Chamberlain: "Finally something fun. Mike Rapoport does some cleanup to allow us to take out module_alloc() out of modules into a new paint shedded execmem_alloc() and execmem_free() so to make emphasis these helpers are actually used outside of modules. It starts with a non-functional changes API rename / placeholders to then allow architectures to define their requirements into a new shiny struct execmem_info with ranges, and requirements for those ranges. Archs now can intitialize this execmem_info as the last part of mm_core_init() if they have to diverge from the norm. Each range is a known type clearly articulated and spelled out in enum execmem_type. Although a lot of this is major cleanup and prep work for future enhancements an immediate clear gain is we get to enable KPROBES without MODULES now. That is ultimately what motiviated to pick this work up again, now with smaller goal as concrete stepping stone" * tag 'modules-6.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux: bpf: remove CONFIG_BPF_JIT dependency on CONFIG_MODULES of kprobes: remove dependency on CONFIG_MODULES powerpc: use CONFIG_EXECMEM instead of CONFIG_MODULES where appropriate x86/ftrace: enable dynamic ftrace without CONFIG_MODULES arch: make execmem setup available regardless of CONFIG_MODULES powerpc: extend execmem_params for kprobes allocations arm64: extend execmem_info for generated code allocations riscv: extend execmem_params for generated code allocations mm/execmem, arch: convert remaining overrides of module_alloc to execmem mm/execmem, arch: convert simple overrides of module_alloc to execmem mm: introduce execmem_alloc() and execmem_free() module: make module_memory_{alloc,free} more self-contained sparc: simplify module_alloc() nios2: define virtual address space for modules mips: module: rename MODULE_START to MODULES_VADDR arm64: module: remove unneeded call to kasan_alloc_module_shadow() kallsyms: replace deprecated strncpy with strscpy module: allow UNUSED_KSYMS_WHITELIST to be relative against objtree.
2024-05-14Merge tag 'arm64-upstream' of ↵Linus Torvalds6-116/+152
git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull arm64 updates from Will Deacon: "The most interesting parts are probably the mm changes from Ryan which optimise the creation of the linear mapping at boot and (separately) implement write-protect support for userfaultfd. Outside of our usual directories, the Kbuild-related changes under scripts/ have been acked by Masahiro whilst the drivers/acpi/ parts have been acked by Rafael and the addition of cpumask_any_and_but() has been acked by Yury. ACPI: - Support for the Firmware ACPI Control Structure (FACS) signature feature which is used to reboot out of hibernation on some systems Kbuild: - Support for building Flat Image Tree (FIT) images, where the kernel Image is compressed alongside a set of devicetree blobs Memory management: - Optimisation of our early page-table manipulation for creation of the linear mapping - Support for userfaultfd write protection, which brings along some nice cleanups to our handling of invalid but present ptes - Extend our use of range TLBI invalidation at EL1 Perf and PMUs: - Ensure that the 'pmu->parent' pointer is correctly initialised by PMU drivers - Avoid allocating 'cpumask_t' types on the stack in some PMU drivers - Fix parsing of the CPU PMU "version" field in assembly code, as it doesn't follow the usual architectural rules - Add best-effort unwinding support for USER_STACKTRACE - Minor driver fixes and cleanups Selftests: - Minor cleanups to the arm64 selftests (missing NULL check, unused variable) Miscellaneous: - Add a command-line alias for disabling 32-bit application support - Add part number for Neoverse-V2 CPUs - Minor fixes and cleanups" * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (64 commits) arm64/mm: Fix pud_user_accessible_page() for PGTABLE_LEVELS <= 2 arm64/mm: Add uffd write-protect support arm64/mm: Move PTE_PRESENT_INVALID to overlay PTE_NG arm64/mm: Remove PTE_PROT_NONE bit arm64/mm: generalize PMD_PRESENT_INVALID for all levels arm64: simplify arch_static_branch/_jump function arm64: Add USER_STACKTRACE support arm64: Add the arm64.no32bit_el0 command line option drivers/perf: hisi: hns3: Actually use devm_add_action_or_reset() drivers/perf: hisi: hns3: Fix out-of-bound access when valid event group drivers/perf: hisi_pcie: Fix out-of-bound access when valid event group kselftest: arm64: Add a null pointer check arm64: defer clearing DAIF.D arm64: assembler: update stale comment for disable_step_tsk arm64/sysreg: Update PIE permission encodings kselftest/arm64: Remove unused parameters in abi test perf/arm-spe: Assign parents for event_source device perf/arm-smmuv3: Assign parents for event_source device perf/arm-dsu: Assign parents for event_source device perf/arm-dmc620: Assign parents for event_source device ...
2024-05-14Makefile: remove redundant tool coverage variablesMasahiro Yamada2-14/+0
Now Kbuild provides reasonable defaults for objtool, sanitizers, and profilers. Remove redundant variables. Note: This commit changes the coverage for some objects: - include arch/mips/vdso/vdso-image.o into UBSAN, GCOV, KCOV - include arch/sparc/vdso/vdso-image-*.o into UBSAN - include arch/sparc/vdso/vma.o into UBSAN - include arch/x86/entry/vdso/extable.o into KASAN, KCSAN, UBSAN, GCOV, KCOV - include arch/x86/entry/vdso/vdso-image-*.o into KASAN, KCSAN, UBSAN, GCOV, KCOV - include arch/x86/entry/vdso/vdso32-setup.o into KASAN, KCSAN, UBSAN, GCOV, KCOV - include arch/x86/entry/vdso/vma.o into GCOV, KCOV - include arch/x86/um/vdso/vma.o into KASAN, GCOV, KCOV I believe these are positive effects because all of them are kernel space objects. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Kees Cook <keescook@chromium.org> Tested-by: Roberto Sassu <roberto.sassu@huawei.com>
2024-05-14arch: make execmem setup available regardless of CONFIG_MODULESMike Rapoport (IBM)1-140/+0
execmem does not depend on modules, on the contrary modules use execmem. To make execmem available when CONFIG_MODULES=n, for instance for kprobes, split execmem_params initialization out from arch/*/kernel/module.c and compile it when CONFIG_EXECMEM=y Signed-off-by: Mike Rapoport (IBM) <rppt@kernel.org> Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org> Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2024-05-14arm64: extend execmem_info for generated code allocationsMike Rapoport (IBM)2-7/+12
The memory allocations for kprobes and BPF on arm64 can be placed anywhere in vmalloc address space and currently this is implemented with overrides of alloc_insn_page() and bpf_jit_alloc_exec() in arm64. Define EXECMEM_KPROBES and EXECMEM_BPF ranges in arm64::execmem_info and drop overrides of alloc_insn_page() and bpf_jit_alloc_exec(). Signed-off-by: Mike Rapoport (IBM) <rppt@kernel.org> Acked-by: Will Deacon <will@kernel.org> Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2024-05-14mm/execmem, arch: convert remaining overrides of module_alloc to execmemMike Rapoport (IBM)1-24/+31
Extend execmem parameters to accommodate more complex overrides of module_alloc() by architectures. This includes specification of a fallback range required by arm, arm64 and powerpc, EXECMEM_MODULE_DATA type required by powerpc, support for allocation of KASAN shadow required by s390 and x86 and support for late initialization of execmem required by arm64. The core implementation of execmem_alloc() takes care of suppressing warnings when the initial allocation fails but there is a fallback range defined. Signed-off-by: Mike Rapoport (IBM) <rppt@kernel.org> Acked-by: Will Deacon <will@kernel.org> Acked-by: Song Liu <song@kernel.org> Tested-by: Liviu Dudau <liviu@dudau.co.uk> Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2024-05-14arm64: module: remove unneeded call to kasan_alloc_module_shadow()Mike Rapoport (IBM)1-5/+0
Since commit f6f37d9320a1 ("arm64: select KASAN_VMALLOC for SW/HW_TAGS modes") KASAN_VMALLOC is always enabled when KASAN is on. This means that allocations in module_alloc() will be tracked by KASAN protection for vmalloc() and that kasan_alloc_module_shadow() will be always an empty inline and there is no point in calling it. Drop meaningless call to kasan_alloc_module_shadow() from module_alloc(). Signed-off-by: Mike Rapoport (IBM) <rppt@kernel.org> Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2024-05-13Merge tag 'perf-core-2024-05-13' of ↵Linus Torvalds1-2/+2
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf events updates from Ingo Molnar: - Combine perf and BPF for fast evalution of HW breakpoint conditions - Add LBR capture support outside of hardware events - Trigger IO signals for watermark_wakeup - Add RAPL support for Intel Arrow Lake and Lunar Lake - Optimize frequency-throttling - Miscellaneous cleanups & fixes * tag 'perf-core-2024-05-13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (21 commits) perf/bpf: Mark perf_event_set_bpf_handler() and perf_event_free_bpf_handler() as inline too selftests/perf_events: Test FASYNC with watermark wakeups perf/ring_buffer: Trigger IO signals for watermark_wakeup perf: Move perf_event_fasync() to perf_event.h perf/bpf: Change the !CONFIG_BPF_SYSCALL stubs to static inlines selftest/bpf: Test a perf BPF program that suppresses side effects perf/bpf: Allow a BPF program to suppress all sample side effects perf/bpf: Remove unneeded uses_default_overflow_handler() perf/bpf: Call BPF handler directly, not through overflow machinery perf/bpf: Remove #ifdef CONFIG_BPF_SYSCALL from struct perf_event members perf/bpf: Create bpf_overflow_handler() stub for !CONFIG_BPF_SYSCALL perf/bpf: Reorder bpf_overflow_handler() ahead of __perf_event_overflow() perf/x86/rapl: Add support for Intel Lunar Lake perf/x86/rapl: Add support for Intel Arrow Lake perf/core: Reduce PMU access to adjust sample freq perf/core: Optimize perf_adjust_freq_unthr_context() perf/x86/amd: Don't reject non-sampling events with configured LBR perf/x86/amd: Support capturing LBR from software events perf/x86/amd: Avoid taking branches before disabling LBR perf/x86/amd: Ensure amd_pmu_core_disable_all() is always inlined ...
2024-05-12Merge tag 'kvmarm-6.10-1' of ↵Paolo Bonzini1-2/+2
git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD KVM/arm64 updates for Linux 6.10 - Move a lot of state that was previously stored on a per vcpu basis into a per-CPU area, because it is only pertinent to the host while the vcpu is loaded. This results in better state tracking, and a smaller vcpu structure. - Add full handling of the ERET/ERETAA/ERETAB instructions in nested virtualisation. The last two instructions also require emulating part of the pointer authentication extension. As a result, the trap handling of pointer authentication has been greattly simplified. - Turn the global (and not very scalable) LPI translation cache into a per-ITS, scalable cache, making non directly injected LPIs much cheaper to make visible to the vcpu. - A batch of pKVM patches, mostly fixes and cleanups, as the upstreaming process seems to be resuming. Fingers crossed! - Allocate PPIs and SGIs outside of the vcpu structure, allowing for smaller EL2 mapping and some flexibility in implementing more or less than 32 private IRQs. - Purge stale mpidr_data if a vcpu is created after the MPIDR map has been created. - Preserve vcpu-specific ID registers across a vcpu reset. - Various minor cleanups and improvements.
2024-05-10Merge branch 'for-next/errata' into for-next/coreWill Deacon3-0/+39
* for-next/errata: arm64: errata: Add workaround for Arm errata 3194386 and 3312417 arm64: cputype: Add Neoverse-V3 definitions arm64: cputype: Add Cortex-X4 definitions arm64: barrier: Restore spec_bar() macro
2024-05-10arm64: errata: Add workaround for Arm errata 3194386 and 3312417Mark Rutland3-0/+39
Cortex-X4 and Neoverse-V3 suffer from errata whereby an MSR to the SSBS special-purpose register does not affect subsequent speculative instructions, permitting speculative store bypassing for a window of time. This is described in their Software Developer Errata Notice (SDEN) documents: * Cortex-X4 SDEN v8.0, erratum 3194386: https://developer.arm.com/documentation/SDEN-2432808/0800/ * Neoverse-V3 SDEN v6.0, erratum 3312417: https://developer.arm.com/documentation/SDEN-2891958/0600/ To workaround these errata, it is necessary to place a speculation barrier (SB) after MSR to the SSBS special-purpose register. This patch adds the requisite SB after writes to SSBS within the kernel, and hides the presence of SSBS from EL0 such that userspace software which cares about SSBS will manipulate this via prctl(PR_GET_SPECULATION_CTRL, ...). Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: James Morse <james.morse@arm.com> Cc: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20240508081400.235362-5-mark.rutland@arm.com Signed-off-by: Will Deacon <will@kernel.org>
2024-05-10kbuild: use $(src) instead of $(srctree)/$(src) for source directoryMasahiro Yamada1-1/+1
Kbuild conventionally uses $(obj)/ for generated files, and $(src)/ for checked-in source files. It is merely a convention without any functional difference. In fact, $(obj) and $(src) are exactly the same, as defined in scripts/Makefile.build: src := $(obj) When the kernel is built in a separate output directory, $(src) does not accurately reflect the source directory location. While Kbuild resolves this discrepancy by specifying VPATH=$(srctree) to search for source files, it does not cover all cases. For example, when adding a header search path for local headers, -I$(srctree)/$(src) is typically passed to the compiler. This introduces inconsistency between upstream and downstream Makefiles because $(src) is used instead of $(srctree)/$(src) for the latter. To address this inconsistency, this commit changes the semantics of $(src) so that it always points to the directory in the source tree. Going forward, the variables used in Makefiles will have the following meanings: $(obj) - directory in the object tree $(src) - directory in the source tree (changed by t