April 2025 - Linux-kselftest-mirror

[PATCH] fix(script): improve safety and formatting for WRITES_STRICT restore

by Alexander Shatalin

From: Alexander Shatalin <sashatalin03(a)gmail.com> This patch improves the safety when restoring WRITES_STRICT by ensuring: - The variable is not empty (`-n`) - The target file is writable (`-w`) Also improves formatting by quoting variables and following shell best practices. Signed-off-by: Alexander Shatalin <sashatalin03(a)gmail.com>

2 days, 7 hours

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[PATCH v6 0/5] userfaultfd move option

by Suren Baghdasaryan

This patch series introduces UFFDIO_MOVE feature to userfaultfd, which has long been implemented and maintained by Andrea in his local tree [1], but was not upstreamed due to lack of use cases where this approach would be better than allocating a new page and copying the contents. Previous upstraming attempts could be found at [6] and [7]. UFFDIO_COPY performs ~20% better than UFFDIO_MOVE when the application needs pages to be allocated [2]. However, with UFFDIO_MOVE, if pages are available (in userspace) for recycling, as is usually the case in heap compaction algorithms, then we can avoid the page allocation and memcpy (done by UFFDIO_COPY). Also, since the pages are recycled in the userspace, we avoid the need to release (via madvise) the pages back to the kernel [3]. We see over 40% reduction (on a Google pixel 6 device) in the compacting thread’s completion time by using UFFDIO_MOVE vs. UFFDIO_COPY. This was measured using a benchmark that emulates a heap compaction implementation using userfaultfd (to allow concurrent accesses by application threads). More details of the usecase are explained in [3]. Furthermore, UFFDIO_MOVE enables moving swapped-out pages without touching them within the same vma. Today, it can only be done by mremap, however it forces splitting the vma. TODOs for follow-up improvements: - cross-mm support. Known differences from single-mm and missing pieces: - memcg recharging (might need to isolate pages in the process) - mm counters - cross-mm deposit table moves - cross-mm test - document the address space where src and dest reside in struct uffdio_move - TLB flush batching. Will require extensive changes to PTL locking in move_pages_pte(). OTOH that might let us reuse parts of mremap code. Changes since v5 [10]: - added logic to split large folios in move_pages_pte(), per David Hildenbrand - added check for PAE before split_huge_pmd() to avoid the split if the move operation can't be done - replaced calls to default_huge_page_size() with read_pmd_pagesize() in uffd_move_pmd test, per David Hildenbrand - fixed the condition in uffd_move_test_common() checking if area alignment is needed Changes since v4 [9]: - added Acked-by in patch 1, per Peter Xu - added description for ctx, mm and mode parameters of move_pages(), per kernel test robot - added Reviewed-by's, per Peter Xu and Axel Rasmussen - removed unused operations in uffd_test_case_ops - refactored uffd-unit-test changes to avoid using global variables and handle pmd moves without page size overrides, per Peter Xu Changes since v3 [8]: - changed retry path in folio_lock_anon_vma_read() to unlock and then relock RCU, per Peter Xu - removed cross-mm support from initial patchset, per David Hildenbrand - replaced BUG_ONs with VM_WARN_ON or WARN_ON_ONCE, per David Hildenbrand - added missing cache flushing, per Lokesh Gidra and Peter Xu - updated manpage text in the patch description, per Peter Xu - renamed internal functions from "remap" to "move", per Peter Xu - added mmap_changing check after taking mmap_lock, per Peter Xu - changed uffd context check to ensure dst_mm is registered onto uffd we are operating on, Peter Xu and David Hildenbrand - changed to non-maybe variants of maybe*_mkwrite(), per David Hildenbrand - fixed warning for CONFIG_TRANSPARENT_HUGEPAGE=n, per kernel test robot - comments cleanup, per David Hildenbrand and Peter Xu - checks for VM_IO,VM_PFNMAP,VM_HUGETLB,..., per David Hildenbrand - prevent moving pinned pages, per Peter Xu - changed uffd tests to call move uffd_test_ctx_clear() at the end of the test run instead of in the beginning of the next run - added support for testcase-specific ops - added test for moving PMD-aligned blocks Changes since v2 [5]: - renamed UFFDIO_REMAP to UFFDIO_MOVE, per David Hildenbrand - rebase over mm-unstable to use folio_move_anon_rmap(), per David Hildenbrand - added text for manpage explaining DONTFORK and KSM requirements for this feature, per David Hildenbrand - check for anon_vma changes in the fast path of folio_lock_anon_vma_read, per Peter Xu - updated the title and description of the first patch, per David Hildenbrand - updating comments in folio_lock_anon_vma_read() explaining the need for anon_vma checks, per David Hildenbrand - changed all mapcount checks to PageAnonExclusive, per Jann Horn and David Hildenbrand - changed counters in remap_swap_pte() from MM_ANONPAGES to MM_SWAPENTS, per Jann Horn - added a check for PTE change after folio is locked in remap_pages_pte(), per Jann Horn - added handling of PMD migration entries and bailout when pmd_devmap(), per Jann Horn - added checks to ensure both src and dst VMAs are writable, per Peter Xu - added UFFD_FEATURE_MOVE, per Peter Xu - removed obsolete comments, per Peter Xu - renamed remap_anon_pte to remap_present_pte, per Peter Xu - added a comment for folio_get_anon_vma() explaining the need for anon_vma checks, per Peter Xu - changed error handling in remap_pages() to make it more clear, per Peter Xu - changed EFAULT to EAGAIN to retry when a hugepage appears or disappears from under us, per Peter Xu - added links to previous upstreaming attempts, per David Hildenbrand Changes since v1 [4]: - add mmget_not_zero in userfaultfd_remap, per Jann Horn - removed extern from function definitions, per Matthew Wilcox - converted to folios in remap_pages_huge_pmd, per Matthew Wilcox - use PageAnonExclusive in remap_pages_huge_pmd, per David Hildenbrand - handle pgtable transfers between MMs, per Jann Horn - ignore concurrent A/D pte bit changes, per Jann Horn - split functions into smaller units, per David Hildenbrand - test for folio_test_large in remap_anon_pte, per Matthew Wilcox - use pte_swp_exclusive for swapcount check, per David Hildenbrand - eliminated use of mmu_notifier_invalidate_range_start_nonblock, per Jann Horn - simplified THP alignment checks, per Jann Horn - refactored the loop inside remap_pages, per Jann Horn - additional clarifying comments, per Jann Horn Main changes since Andrea's last version [1]: - Trivial translations from page to folio, mmap_sem to mmap_lock - Replace pmd_trans_unstable() with pte_offset_map_nolock() and handle its possible failure - Move pte mapping into remap_pages_pte to allow for retries when source page or anon_vma is contended. Since pte_offset_map_nolock() start RCU read section, we can't block anymore after mapping a pte, so have to unmap the ptesm do the locking and retry. - Add and use anon_vma_trylock_write() to avoid blocking while in RCU read section. - Accommodate changes in mmu_notifier_range_init() API, switch to mmu_notifier_invalidate_range_start_nonblock() to avoid blocking while in RCU read section. - Open-code now removed __swp_swapcount() - Replace pmd_read_atomic() with pmdp_get_lockless() - Add new selftest for UFFDIO_MOVE [1] https://gitlab.com/aarcange/aa/-/commit/2aec7aea56b10438a3881a20a411aa4b1fc… [2] https://lore.kernel.org/all/1425575884-2574-1-git-send-email-aarcange@redha… [3] https://lore.kernel.org/linux-mm/CA+EESO4uO84SSnBhArH4HvLNhaUQ5nZKNKXqxRCyj… [4] https://lore.kernel.org/all/20230914152620.2743033-1-surenb@google.com/ [5] https://lore.kernel.org/all/20230923013148.1390521-1-surenb@google.com/ [6] https://lore.kernel.org/all/1425575884-2574-21-git-send-email-aarcange@redh… [7] https://lore.kernel.org/all/cover.1547251023.git.blake.caldwell@colorado.ed… [8] https://lore.kernel.org/all/20231009064230.2952396-1-surenb@google.com/ [9] https://lore.kernel.org/all/20231028003819.652322-1-surenb@google.com/ [10] https://lore.kernel.org/all/20231121171643.3719880-1-surenb@google.com/ Andrea Arcangeli (2): mm/rmap: support move to different root anon_vma in folio_move_anon_rmap() userfaultfd: UFFDIO_MOVE uABI Suren Baghdasaryan (3): selftests/mm: call uffd_test_ctx_clear at the end of the test selftests/mm: add uffd_test_case_ops to allow test case-specific operations selftests/mm: add UFFDIO_MOVE ioctl test Documentation/admin-guide/mm/userfaultfd.rst | 3 + fs/userfaultfd.c | 72 +++ include/linux/rmap.h | 5 + include/linux/userfaultfd_k.h | 11 + include/uapi/linux/userfaultfd.h | 29 +- mm/huge_memory.c | 122 ++++ mm/khugepaged.c | 3 + mm/rmap.c | 30 + mm/userfaultfd.c | 614 +++++++++++++++++++ tools/testing/selftests/mm/uffd-common.c | 39 +- tools/testing/selftests/mm/uffd-common.h | 9 + tools/testing/selftests/mm/uffd-stress.c | 5 +- tools/testing/selftests/mm/uffd-unit-tests.c | 192 ++++++ 13 files changed, 1130 insertions(+), 4 deletions(-) -- 2.43.0.rc2.451.g8631bc7472-goog

2 days, 14 hours

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[PATCH] selftests: pid_namespace: Fix pid_max build with missing mount header

by Niko Nikolov

Add #include <sys/mount.h> to pid_max.c to fix build errors caused by implicit declarations of mount() and umount2(), and undefined symbols MS_PRIVATE, MS_REC, and MNT_DETACH. Signed-off-by: Niko Nikolov <nikolay.niko.nikolov(a)gmail.com> --- tools/testing/selftests/pid_namespace/pid_max.c | 1 + 1 file changed, 1 insertion(+) diff --git a/tools/testing/selftests/pid_namespace/pid_max.c b/tools/testing/selftests/pid_namespace/pid_max.c index 51c414faabb0..972bedc475f1 100644 --- a/tools/testing/selftests/pid_namespace/pid_max.c +++ b/tools/testing/selftests/pid_namespace/pid_max.c @@ -11,6 +11,7 @@ #include <string.h> #include <syscall.h> #include <sys/wait.h> +#include <sys/mount.h> #include "../kselftest_harness.h" #include "../pidfd/pidfd.h" -- 2.49.0

2 days, 16 hours

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[PATCH bpf-next v3 0/2] bpf: Allow access to const void pointer arguments in tracing programs

by KaFai Wan

If we try to access argument which is pointer to const void, it's an UNKNOWN type, verifier will fail to load. Use is_void_or_int_ptr to check if type is void or int pointer. Add a selftest to check it. --- KaFai Wan (2): bpf: Allow access to const void pointer arguments in tracing programs selftests/bpf: Add test to access const void pointer argument in tracing program kernel/bpf/btf.c | 13 +++---------- net/bpf/test_run.c | 8 +++++++- .../selftests/bpf/progs/verifier_btf_ctx_access.c | 12 ++++++++++++ 3 files changed, 22 insertions(+), 11 deletions(-) Changelog: v2->v3: Addressed comments from jirka - remove duplicate checks for void pointer Details in here: https://lore.kernel.org/bpf/20250416161756.1079178-1-kafai.wan@hotmail.com/ v1->v2: Addressed comments from jirka - use btf_type_is_void to check if type is void - merge is_void_ptr and is_int_ptr to is_void_or_int_ptr - fix selftests Details in here: https://lore.kernel.org/all/20250412170626.3638516-1-kafai.wan@hotmail.com/ -- 2.43.0

2 days, 19 hours

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[PATCH] lib: Ensure prime numbers tests are included in KUnit test runs

by Mark Brown

When the select of PRIME_MUMBERS was removed from it's KUnit test Kconfig nothing was added to the KUnit configs, meaning that when run via the KUnit runner the tests are neither built nor run. Add PRIME_NUMBERS to all_tests.config so they are enabled when the KUnit runner builds the kernel. Fixes: 3f2925174f8b ("lib/prime_numbers: KUnit test should not select PRIME_NUMBERS") Signed-off-by: Mark Brown <broonie(a)kernel.org> --- tools/testing/kunit/configs/all_tests.config | 2 ++ 1 file changed, 2 insertions(+) diff --git a/tools/testing/kunit/configs/all_tests.config b/tools/testing/kunit/configs/all_tests.config index cdd9782f9646..7bb885b0c32d 100644 --- a/tools/testing/kunit/configs/all_tests.config +++ b/tools/testing/kunit/configs/all_tests.config @@ -43,6 +43,8 @@ CONFIG_REGMAP_BUILD=y CONFIG_AUDIT=y +CONFIG_PRIME_NUMBERS=y + CONFIG_SECURITY=y CONFIG_SECURITY_APPARMOR=y CONFIG_SECURITY_LANDLOCK=y --- base-commit: 9c32cda43eb78f78c73aee4aa344b777714e259b change-id: 20250422-lib-fix-prime-numbers-kunit-323659c2cfe2 Best regards, -- Mark Brown <broonie(a)kernel.org>

2 days, 21 hours

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[PATCH v2] tracing: selftests: Add testing a user string to filters

by Steven Rostedt

From: Steven Rostedt <rostedt(a)goodmis.org> Running the following commands was broken: # cd /sys/kernel/tracing # echo "filename.ustring ~ \"/proc*\"" > events/syscalls/sys_enter_openat/filter # echo 1 > events/syscalls/sys_enter_openat/enable # ls /proc/$$/maps # cat trace And would produce nothing when it should have produced something like: ls-1192 [007] ..... 8169.828333: sys_openat(dfd: ffffffffffffff9c, filename: 7efc18359904, flags: 80000, mode: 0) Add a test to check this case so that it will be caught if it breaks again. Link: https://lore.kernel.org/linux-trace-kernel/20250417183003.505835fb@gandalf.… Signed-off-by: Steven Rostedt (Google) <rostedt(a)goodmis.org> --- Changes since v1: https://lore.kernel.org/20250417223323.3edb4f6c@batman.local.home - Use $TMPDIR instead of $TESTDIR as test file (Masami Hiramatsu) .../test.d/filter/event-filter-function.tc | 20 +++++++++++++++++++ 1 file changed, 20 insertions(+) diff --git a/tools/testing/selftests/ftrace/test.d/filter/event-filter-function.tc b/tools/testing/selftests/ftrace/test.d/filter/event-filter-function.tc index 118247b8dd84..c62165fabd0c 100644 --- a/tools/testing/selftests/ftrace/test.d/filter/event-filter-function.tc +++ b/tools/testing/selftests/ftrace/test.d/filter/event-filter-function.tc @@ -80,6 +80,26 @@ if [ $misscnt -gt 0 ]; then exit_fail fi +# Check strings too +if [ -f events/syscalls/sys_enter_openat/filter ]; then + DIRNAME=`basename $TMPDIR` + echo "filename.ustring ~ \"*$DIRNAME*\"" > events/syscalls/sys_enter_openat/filter + echo 1 > events/syscalls/sys_enter_openat/enable + echo 1 > tracing_on + ls /bin/sh + nocnt=`grep openat trace | wc -l` + ls $TMPDIR + echo 0 > tracing_on + hitcnt=`grep openat trace | wc -l`; + echo 0 > events/syscalls/sys_enter_openat/enable + if [ $nocnt -gt 0 ]; then + exit_fail + fi + if [ $hitcnt -eq 0 ]; then + exit_fail + fi +fi + reset_events_filter exit 0 -- 2.47.2

2 days, 21 hours

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[PATCH RFC v7 0/8] Add NUMA mempolicy support for KVM guest-memfd

by Shivank Garg

KVM's guest-memfd memory backend currently lacks support for NUMA policy enforcement, causing guest memory allocations to be distributed arbitrarily across host NUMA nodes regardless of the policy specified by the VMM. This occurs because conventional userspace NUMA control mechanisms like mbind() are ineffective with guest-memfd, as the memory isn't directly mapped to userspace when allocations occur. This patch-series adds NUMA-aware memory placement for guest_memfd backed KVM guests. Based on community feedback, the approach has evolved as follows: - v1,v2: Extended the KVM_CREATE_GUEST_MEMFD IOCTL to pass mempolicy. - v3: Introduced fbind() syscall for VMM memory-placement configuration. - v4-v6: Current approach using shared_policy support and vm_ops (based on suggestions from David[1] and guest_memfd biweekly upstream calls[2][4]). - v7: Use inodes to store NUMA policy instead of file[5]. == Implementation == This series implements proper NUMA policy support for guest-memfd by: 1. Adding mempolicy-aware allocation APIs to the filemap layer. 2. Add custom inodes (via a dedicated slab-allocated inode cache, kvm_gmem_inode_info) to store NUMA policy and metadata for guest memory. 3. Implementing get/set_policy vm_ops in guest_memfd to support shared policy. With these changes, VMMs can now control guest memory placement by specifying: - Policy modes: default, bind, interleave, or preferred - Host NUMA nodes: List of target nodes for memory allocation Policies only affect future allocations and do not migrate existing memory. This matches mbind(2)'s default behavior which affects only new allocations unless overridden with MPOL_MF_MOVE/MPOL_MF_MOVE_ALL flags (Not supported for guest_memfd as it is unmovable). This series builds on the existing guest-memfd support in KVM and provides a clean integration path for NUMA-aware memory management in confidential computing environments. The work is primarily focused on supporting SEV-SNP requirements, though the benefits extend to any VMM using the guest-memfd backend that needs control over guest memory placement. == Example usage with QEMU (requires patched QEMU from [3]) == Snippet of the QEMU changes[3] needed to support this feature: /* Create and map guest-memfd region */ new_block->guest_memfd = kvm_create_guest_memfd( new_block->max_length, 0, errp); ... void *ptr_memfd = mmap(NULL, new_block->max_length, PROT_READ | PROT_WRITE, MAP_SHARED, new_block->guest_memfd, 0); ... /* Apply NUMA policy */ int ret = mbind(ptr_memfd, new_block->max_length, backend->policy, backend->host_nodes, maxnode+1, 0); ... QEMU Command to run SEV-SNP guest with interleaved memory across nodes 0 and 1 of the host: $ qemu-system-x86_64 \ -enable-kvm \ ... -machine memory-encryption=sev0,vmport=off \ -object sev-snp-guest,id=sev0,cbitpos=51,reduced-phys-bits=1 \ -numa node,nodeid=0,memdev=ram0,cpus=0-15 \ -object memory-backend-memfd,id=ram0,host-nodes=0-1,policy=interleave,size=1024M,share=true,prealloc=false == Experiment and Analysis == SEV-SNP enabled host, AMD Zen 3, 2 socket 2 NUMA node system NUMA for Policy Guest Node 0: policy=interleave, host-node=0-1 Test: Allocate and touch 50GB inside guest on node=0. * Generic Kernel (without NUMA supported guest-memfd): Node 0 Node 1 Total Before running Test: MemUsed 9981.60 3312.00 13293.60 After running Test: MemUsed 61451.72 3201.62 64653.34 Arbitrary allocations: all ~50GB allocated on node 0. * With NUMA supported guest-memfd: Node 0 Node 1 Total Before running Test: MemUsed 5003.88 3963.07 8966.94 After running Test: MemUsed 30607.55 29670.00 60277.55 Balanced memory distribution: Equal increase (~25GB) on both nodes. == Conclusion == Adding the NUMA-aware memory management to guest_memfd will make a lot of sense. Improving performance of memory-intensive and locality-sensitive workloads with fine-grained control over guest memory allocations, as pointed out in the analysis. Please review and provide feedback! Thanks, Shivank [1] https://lore.kernel.org/all/6fbef654-36e2-4be5-906e-2a648a845278@redhat.com [2] https://lore.kernel.org/all/6f2bfac2-d9e7-4e4a-9298-7accded16b4f@redhat.com [3] https://github.com/shivankgarg98/qemu/tree/guest_memfd_mbind_NUMA [4] https://lore.kernel.org/all/2b77e055-98ac-43a1-a7ad-9f9065d7f38f@amd.com [5] https://lore.kernel.org/all/diqzbjumm167.fsf@ackerleytng-ctop.c.googlers.com == Earlier postings and changelogs == v7 (current): - Add fixes suggested by Vlastimil and Ackerley. - Store NUMA policy in custom inode struct instead of file. v6: - https://lore.kernel.org/all/20250226082549.6034-1-shivankg@amd.com - Rebase to linux mainline - Drop RFC tag - Add selftests to ensure NUMA support for guest_memfd works correctly. v5: - https://lore.kernel.org/all/20250219101559.414878-1-shivankg@amd.com - Fix documentation and style issues. - Use EXPORT_SYMBOL_GPL - Split preparatory change in separate patch v4: - https://lore.kernel.org/all/20250210063227.41125-1-shivankg@amd.com - Dropped fbind() approach in favor of shared policy support. v3: - https://lore.kernel.org/all/20241105164549.154700-1-shivankg@amd.com - Introduce fbind() syscall and drop the IOCTL-based approach. v2: - https://lore.kernel.org/all/20240919094438.10987-1-shivankg@amd.com - Add fixes suggested by Matthew Wilcox. v1: - https://lore.kernel.org/all/20240916165743.201087-1-shivankg@amd.com - Proposed IOCTL based approach to pass NUMA mempolicy. Ackerley Tng (1): KVM: guest_memfd: Make guest mem use guest mem inodes instead of anonymous inodes Shivank Garg (6): mm/mempolicy: Export memory policy symbols security: Export security_inode_init_security_anon for KVM guest_memfd KVM: Add kvm_gmem_exit() cleanup function KVM: guest_memfd: Add slab-allocated inode cache KVM: guest_memfd: Enforce NUMA mempolicy using shared policy KVM: guest_memfd: selftests: Add tests for mmap and NUMA policy support Shivansh Dhiman (1): mm/filemap: Add mempolicy support to the filemap layer include/linux/pagemap.h | 41 +++ include/uapi/linux/magic.h | 1 + mm/filemap.c | 27 +- mm/mempolicy.c | 6 + security/security.c | 1 + .../testing/selftests/kvm/guest_memfd_test.c | 86 +++++- virt/kvm/guest_memfd.c | 261 ++++++++++++++++-- virt/kvm/kvm_main.c | 2 + virt/kvm/kvm_mm.h | 6 + 9 files changed, 402 insertions(+), 29 deletions(-) -- 2.34.1

2 days, 22 hours

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[PATCH v4 net-next 00/15] AccECN protocol patch series

by chia-yu.chang＠nokia-bell-labs.com

From: Chia-Yu Chang <chia-yu.chang(a)nokia-bell-labs.com> Hello, Plese find the v4: v4 (18-Apr-2025) - Fix 32-bit ARM assertion for alignment reuirement (Simon Horman <horms(a)kernel.org>) v3 (14-Apr-2025) - Fix patch apply issue in v2 (Jakub Kicinski <kuba(a)kernel.org>) v2 (18-Mar-2025) - Add one missing patch from previous AccECN protocol preparation patch series to this patch series The full patch series can be found in https://github.com/L4STeam/linux-net-next/commits/upstream_l4steam/ The Accurate ECN draft can be found in https://datatracker.ietf.org/doc/html/draft-ietf-tcpm-accurate-ecn-28 Best regards, Chia-Yu Chia-Yu Chang (1): tcp: accecn: AccECN option failure handling Ilpo Järvinen (14): tcp: reorganize SYN ECN code tcp: fast path functions later tcp: AccECN core tcp: accecn: AccECN negotiation tcp: accecn: add AccECN rx byte counters tcp: accecn: AccECN needs to know delivered bytes tcp: allow embedding leftover into option padding tcp: sack option handling improvements tcp: accecn: AccECN option tcp: accecn: AccECN option send control tcp: accecn: AccECN option ceb/cep heuristic tcp: accecn: AccECN ACE field multi-wrap heuristic tcp: accecn: try to fit AccECN option with SACK tcp: try to avoid safer when ACKs are thinned include/linux/tcp.h | 27 +- include/net/netns/ipv4.h | 2 + include/net/tcp.h | 198 +++++++++++-- include/uapi/linux/tcp.h | 7 + net/ipv4/syncookies.c | 3 + net/ipv4/sysctl_net_ipv4.c | 19 ++ net/ipv4/tcp.c | 26 +- net/ipv4/tcp_input.c | 591 +++++++++++++++++++++++++++++++++++-- net/ipv4/tcp_ipv4.c | 5 +- net/ipv4/tcp_minisocks.c | 92 +++++- net/ipv4/tcp_output.c | 302 +++++++++++++++++-- net/ipv6/syncookies.c | 1 + net/ipv6/tcp_ipv6.c | 1 + 13 files changed, 1178 insertions(+), 96 deletions(-) -- 2.34.1

2 days, 23 hours

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[PATCH v2 0/5] riscv: misaligned: fix interruptible context and add tests

by Clément Léger

This series fixes misaligned access handling when in non interruptible context by reenabling interrupts when possible. A previous commit changed raw_copy_from_user() with copy_from_user() which enables page faulting and thus can sleep. While correct, a warning is now triggered due to being called in an invalid context (sleeping in non-interruptible). This series fixes that problem by factorizing misaligned load/store entry in a single function than reenables interrupt if the interrupted context had interrupts enabled. In order for misaligned handling problems to be caught sooner, add a kselftest for all the currently supported instructions . Note: these commits were actually part of another larger series for misaligned request delegation but was split since it isn't directly required. V2: - Use an array of struct to simplify misaligned load/store selection - Revert use of irqentry_enter()/exit() to irqentry_nmi_enter() for kernel space. Clément Léger (5): riscv: misaligned: factorize trap handling riscv: misaligned: enable IRQs while handling misaligned accesses riscv: misaligned: use get_user() instead of __get_user() Documentation/sysctl: add riscv to unaligned-trap supported archs selftests: riscv: add misaligned access testing Documentation/admin-guide/sysctl/kernel.rst | 4 +- arch/riscv/kernel/traps.c | 64 +++-- arch/riscv/kernel/traps_misaligned.c | 2 +- .../selftests/riscv/misaligned/.gitignore | 1 + .../selftests/riscv/misaligned/Makefile | 12 + .../selftests/riscv/misaligned/common.S | 33 +++ .../testing/selftests/riscv/misaligned/fpu.S | 180 +++++++++++++ tools/testing/selftests/riscv/misaligned/gp.S | 103 +++++++ .../selftests/riscv/misaligned/misaligned.c | 254 ++++++++++++++++++ 9 files changed, 623 insertions(+), 30 deletions(-) create mode 100644 tools/testing/selftests/riscv/misaligned/.gitignore create mode 100644 tools/testing/selftests/riscv/misaligned/Makefile create mode 100644 tools/testing/selftests/riscv/misaligned/common.S create mode 100644 tools/testing/selftests/riscv/misaligned/fpu.S create mode 100644 tools/testing/selftests/riscv/misaligned/gp.S create mode 100644 tools/testing/selftests/riscv/misaligned/misaligned.c -- 2.49.0

2 days, 23 hours

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[PATCH v2 0/5] KVM: Improve VMware guest support

by Zack Rusin

This is the second version of a series that lets us run VMware Workstation on Linux on top of KVM. The most significant change in this series is the introduction of CONFIG_KVM_VMWARE which is, in general, a nice cleanup for various bits of VMware compatibility code that have been scattered around KVM. (first patch) The rest of the series builds upon the VMware platform to implement features that are needed to run VMware guests without any modifications on top of KVM: - ability to turn on the VMware backdoor at runtime on a per-vm basis (used to be a kernel boot argument only) - support for VMware hypercalls - VMware products have a huge collection of hypercalls, all of which are handled in userspace, - support for handling legacy VMware backdoor in L0 in nested configs - in cases where we have WS running a Windows VBS guest, the L0 would be KVM, L1 Hyper-V so by default VMware Tools backdoor calls endup in Hyper-V which can not handle them, so introduce a cap to let L0 handle those. The final change in the series is a kselftest of the VMware hypercall functionality. Cc: Paolo Bonzini <pbonzini(a)redhat.com> Cc: Jonathan Corbet <corbet(a)lwn.net> Cc: Sean Christopherson <seanjc(a)google.com> Cc: Thomas Gleixner <tglx(a)linutronix.de> Cc: Ingo Molnar <mingo(a)redhat.com> Cc: Borislav Petkov <bp(a)alien8.de> Cc: Dave Hansen <dave.hansen(a)linux.intel.com> Cc: x86(a)kernel.org Cc: "H. Peter Anvin" <hpa(a)zytor.com> Cc: Zack Rusin <zack.rusin(a)broadcom.com> Cc: Doug Covelli <doug.covelli(a)broadcom.com> Cc: Shuah Khan <shuah(a)kernel.org> Cc: Namhyung Kim <namhyung(a)kernel.org> Cc: Arnaldo Carvalho de Melo <acme(a)redhat.com> Cc: Michael Ellerman <mpe(a)ellerman.id.au> Cc: Joel Stanley <joel(a)jms.id.au> Cc: Isaku Yamahata <isaku.yamahata(a)intel.com> Cc: kvm(a)vger.kernel.org Cc: linux-doc(a)vger.kernel.org Cc: linux-kernel(a)vger.kernel.org Cc: linux-kselftest(a)vger.kernel.org Zack Rusin (5): KVM: x86: Centralize KVM's VMware code KVM: x86: Allow enabling of the vmware backdoor via a cap KVM: x86: Add support for VMware guest specific hypercalls KVM: x86: Add support for legacy VMware backdoors in nested setups KVM: selftests: x86: Add a test for KVM_CAP_X86_VMWARE_HYPERCALL Documentation/virt/kvm/api.rst | 86 +++++++- MAINTAINERS | 9 + arch/x86/include/asm/kvm_host.h | 13 ++ arch/x86/kvm/Kconfig | 16 ++ arch/x86/kvm/Makefile | 1 + arch/x86/kvm/emulate.c | 11 +- arch/x86/kvm/kvm_vmware.c | 85 ++++++++ arch/x86/kvm/kvm_vmware.h | 189 ++++++++++++++++++ arch/x86/kvm/pmu.c | 39 +--- arch/x86/kvm/pmu.h | 4 - arch/x86/kvm/svm/nested.c | 6 + arch/x86/kvm/svm/svm.c | 10 +- arch/x86/kvm/vmx/nested.c | 6 + arch/x86/kvm/vmx/vmx.c | 5 +- arch/x86/kvm/x86.c | 74 +++---- arch/x86/kvm/x86.h | 2 - include/uapi/linux/kvm.h | 27 +++ tools/include/uapi/linux/kvm.h | 3 + tools/testing/selftests/kvm/Makefile.kvm | 1 + .../selftests/kvm/x86/vmware_hypercall_test.c | 121 +++++++++++ 20 files changed, 614 insertions(+), 94 deletions(-) create mode 100644 arch/x86/kvm/kvm_vmware.c create mode 100644 arch/x86/kvm/kvm_vmware.h create mode 100644 tools/testing/selftests/kvm/x86/vmware_hypercall_test.c -- 2.48.1

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Linux-kselftest-mirror April 2025