April 2025 - Linux-kselftest-mirror

[PATCH 0/3] RISC-V KVM selftests improvements

by Atish Patra

This series improves the following tests. 1. Get-reg-list : Adds vector support 2. SBI PMU test : Distinguish between different types of illegal exception The first patch is just helper patch that adds stval support during exception handling. Signed-off-by: Atish Patra <atishp(a)rivosinc.com> --- Atish Patra (3): KVM: riscv: selftests: Add stval to exception handling KVM: riscv: selftests: Decode stval to identify exact exception type KVM: riscv: selftests: Add vector extension tests .../selftests/kvm/include/riscv/processor.h | 1 + tools/testing/selftests/kvm/lib/riscv/handlers.S | 2 + tools/testing/selftests/kvm/riscv/get-reg-list.c | 111 ++++++++++++++++++++- tools/testing/selftests/kvm/riscv/sbi_pmu_test.c | 32 ++++++ 4 files changed, 145 insertions(+), 1 deletion(-) --- base-commit: b3f263a98d30fe2e33eefea297598c590ee3560e change-id: 20250324-kvm_selftest_improve-9bedb9f0a6d3 -- Regards, Atish patra

36 minutes

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[PATCH v2 security-next 0/4] Introducing Hornet LSM

by Blaise Boscaccy

This patch series introduces the Hornet LSM. The goal of Hornet is to provide a signature verification mechanism for eBPF programs. eBPF has similar requirements to that of modules when it comes to loading: find symbol addresses, fix up ELF relocations, some struct field offset handling stuff called CO-RE (compile-once run-anywhere), and some other miscellaneous bookkeeping. During eBPF program compilation, pseudo-values get written to the immediate operands of instructions. During loading, those pseudo-values get rewritten with concrete addresses or data applicable to the currently running system, e.g., a kallsyms address or an fd for a map. This needs to happen before the instructions for a bpf program are loaded into the kernel via the bpf() syscall. Unlike modules, an in-kernel loader unfortunately doesn't exist. Typically, the instruction rewriting is done dynamically in userspace via libbpf. Since the relocations and instruction modifications are happening in userspace, and their values may change depending upon the running system, this breaks known signature verification mechanisms. Light skeleton programs were introduced in order to support early loading of eBPF programs along with user-mode drivers. They utilize a separate eBPF program that can load a target eBPF program and perform all necessary relocations in-kernel without needing a working userspace. Light skeletons were mentioned as a possible path forward for signature verification. Hornet takes a simple approach to light-skeleton-based eBPF signature verification. A PKCS#7 signature of a data buffer containing the raw instructions of an eBPF program, followed by the initial values of any maps used by the program is used. A utility script is provided to parse and extract the contents of autogenerated header files created via bpftool. That payload can then be signed and appended to the light skeleton executable. Maps are frozen to prevent TOCTOU bugs where a sufficiently privileged user could rewrite map data between the calls to BPF_PROG_LOAD and BPF_PROG_RUN. Additionally, both sparse-array-based and fd_array_cnt-based map fd arrays are supported for signature verification. References: [1] https://lore.kernel.org/bpf/20220209054315.73833-1-alexei.starovoitov@gmail… [2] https://lore.kernel.org/bpf/CAADnVQ+wPK1KKZhCgb-Nnf0Xfjk8M1UpX5fnXC=cBzdEYb… Change list: - v1 -> v2 - Jargon clarification, maintainer entry and a few cosmetic fixes Revisions: - v1 https://lore.kernel.org/bpf/20250321164537.16719-1-bboscaccy@linux.microsof… Blaise Boscaccy (4): security: Hornet LSM hornet: Introduce sign-ebpf hornet: Add a light-skeleton data extactor script selftests/hornet: Add a selftest for the Hornet LSM Documentation/admin-guide/LSM/Hornet.rst | 53 +++ Documentation/admin-guide/LSM/index.rst | 1 + MAINTAINERS | 9 + crypto/asymmetric_keys/pkcs7_verify.c | 10 + include/linux/kernel_read_file.h | 1 + include/linux/verification.h | 1 + include/uapi/linux/lsm.h | 1 + scripts/Makefile | 1 + scripts/hornet/Makefile | 5 + scripts/hornet/extract-skel.sh | 29 ++ scripts/hornet/sign-ebpf.c | 411 +++++++++++++++++++ security/Kconfig | 3 +- security/Makefile | 1 + security/hornet/Kconfig | 11 + security/hornet/Makefile | 4 + security/hornet/hornet_lsm.c | 239 +++++++++++ tools/testing/selftests/Makefile | 1 + tools/testing/selftests/hornet/Makefile | 51 +++ tools/testing/selftests/hornet/loader.c | 21 + tools/testing/selftests/hornet/trivial.bpf.c | 33 ++ 20 files changed, 885 insertions(+), 1 deletion(-) create mode 100644 Documentation/admin-guide/LSM/Hornet.rst create mode 100644 scripts/hornet/Makefile create mode 100755 scripts/hornet/extract-skel.sh create mode 100644 scripts/hornet/sign-ebpf.c create mode 100644 security/hornet/Kconfig create mode 100644 security/hornet/Makefile create mode 100644 security/hornet/hornet_lsm.c create mode 100644 tools/testing/selftests/hornet/Makefile create mode 100644 tools/testing/selftests/hornet/loader.c create mode 100644 tools/testing/selftests/hornet/trivial.bpf.c -- 2.48.1

50 minutes

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[PATCH v4 00/38] Mediated vPMU 4.0 for x86

by Mingwei Zhang

With joint effort from the upstream KVM community, we come up with the 4th version of mediated vPMU for x86. We have made the following changes on top of the previous RFC v3. v3 -> v4 - Rebase whole patchset on 6.14-rc3 base. - Address Peter's comments on Perf part. - Address Sean's comments on KVM part. * Change key word "passthrough" to "mediated" in all patches * Change static enabling to user space dynamic enabling via KVM_CAP_PMU_CAPABILITY. * Only support GLOBAL_CTRL save/restore with VMCS exec_ctrl, drop the MSR save/retore list support for GLOBAL_CTRL, thus the support of mediated vPMU is constrained to SapphireRapids and later CPUs on Intel side. * Merge some small changes into a single patch. - Address Sandipan's comment on invalid pmu pointer. - Add back "eventsel_hw" and "fixed_ctr_ctrl_hw" to avoid to directly manipulate pmc->eventsel and pmu->fixed_ctr_ctrl. Testing (Intel side): - Perf-based legacy vPMU (force emulation on/off) * Kselftests pmu_counters_test, pmu_event_filter_test and vmx_pmu_caps_test pass. * KUT PMU tests pmu, pmu_lbr, pmu_pebs pass. * Basic perf counting/sampling tests in 3 scenarios, guest-only, host-only and host-guest coexistence all pass. - Mediated vPMU (force emulation on/off) * Kselftests pmu_counters_test, pmu_event_filter_test and vmx_pmu_caps_test pass. * KUT PMU tests pmu, pmu_lbr, pmu_pebs pass. * Basic perf counting/sampling tests in 3 scenarios, guest-only, host-only and host-guest coexistence all pass. - Failures. All above tests passed on Intel Granite Rapids as well except a failure on KUT/pmu_pebs. * GP counter 0 (0xfffffffffffe): PEBS record (written seq 0) is verified (including size, counters and cfg). * The pebs_data_cfg (0xb500000000) doesn't match with the effective MSR_PEBS_DATA_CFG (0x0). * This failure has nothing to do with this mediated vPMU patch set. The failure is caused by Granite Rapids supported timed PEBS which needs extra support on Qemu and KUT/pmu_pebs. These extra support would be sent in separate patches later. Testing (AMD side): - Kselftests pmu_counters_test, pmu_event_filter_test and vmx_pmu_caps_test all pass - legacy guest with KUT/pmu: * qmeu option: -cpu host, -perfctr-core * when set force_emulation_prefix=1, passes * when set force_emulation_prefix=0, passes - perfmon-v1 guest with KUT/pmu: * qmeu option: -cpu host, -perfmon-v2 * when set force_emulation_prefix=1, passes * when set force_emulation_prefix=0, passes - perfmon-v2 guest with KUT/pmu: * qmeu option: -cpu host * when set force_emulation_prefix=1, passes * when set force_emulation_prefix=0, passes - perf_fuzzer (perfmon-v2): * fails with soft lockup in guest in current version. * culprit could be between 6.13 ~ 6.14-rc3 within KVM * Series tested on 6.12 and 6.13 without issue. Note: a QEMU series is needed to run mediated vPMU v4: - https://lore.kernel.org/all/20250324123712.34096-1-dapeng1.mi@linux.intel.c… History: - RFC v3: https://lore.kernel.org/all/20240801045907.4010984-1-mizhang@google.com/ - RFC v2: https://lore.kernel.org/all/20240506053020.3911940-1-mizhang@google.com/ - RFC v1: https://lore.kernel.org/all/20240126085444.324918-1-xiong.y.zhang@linux.int… Dapeng Mi (18): KVM: x86/pmu: Introduce enable_mediated_pmu global parameter KVM: x86/pmu: Check PMU cpuid configuration from user space KVM: x86: Rename vmx_vmentry/vmexit_ctrl() helpers KVM: x86/pmu: Add perf_capabilities field in struct kvm_host_values{} KVM: x86/pmu: Move PMU_CAP_{FW_WRITES,LBR_FMT} into msr-index.h header KVM: VMX: Add macros to wrap around {secondary,tertiary}_exec_controls_changebit() KVM: x86/pmu: Check if mediated vPMU can intercept rdpmc KVM: x86/pmu/vmx: Save/load guest IA32_PERF_GLOBAL_CTRL with vm_exit/entry_ctrl KVM: x86/pmu: Optimize intel/amd_pmu_refresh() helpers KVM: x86/pmu: Setup PMU MSRs' interception mode KVM: x86/pmu: Handle PMU MSRs interception and event filtering KVM: x86/pmu: Switch host/guest PMU context at vm-exit/vm-entry KVM: x86/pmu: Handle emulated instruction for mediated vPMU KVM: nVMX: Add macros to simplify nested MSR interception setting KVM: selftests: Add mediated vPMU supported for pmu tests KVM: Selftests: Support mediated vPMU for vmx_pmu_caps_test KVM: Selftests: Fix pmu_counters_test error for mediated vPMU KVM: x86/pmu: Expose enable_mediated_pmu parameter to user space Kan Liang (8): perf: Support get/put mediated PMU interfaces perf: Skip pmu_ctx based on event_type perf: Clean up perf ctx time perf: Add a EVENT_GUEST flag perf: Add generic exclude_guest support perf: Add switch_guest_ctx() interface perf/x86: Support switch_guest_ctx interface perf/x86/intel: Support PERF_PMU_CAP_MEDIATED_VPMU Mingwei Zhang (5): perf/x86: Forbid PMI handler when guest own PMU perf/x86/core: Plumb mediated PMU capability from x86_pmu to x86_pmu_cap KVM: x86/pmu: Exclude PMU MSRs in vmx_get_passthrough_msr_slot() KVM: x86/pmu: introduce eventsel_hw to prepare for pmu event filtering KVM: nVMX: Add nested virtualization support for mediated PMU Sandipan Das (4): perf/x86/core: Do not set bit width for unavailable counters KVM: x86/pmu: Add AMD PMU registers to direct access list KVM: x86/pmu/svm: Set GuestOnly bit and clear HostOnly bit when guest write to event selectors perf/x86/amd: Support PERF_PMU_CAP_MEDIATED_VPMU for AMD host Xiong Zhang (3): x86/irq: Factor out common code for installing kvm irq handler perf: core/x86: Register a new vector for KVM GUEST PMI KVM: x86/pmu: Register KVM_GUEST_PMI_VECTOR handler arch/x86/events/amd/core.c | 2 + arch/x86/events/core.c | 40 +- arch/x86/events/intel/core.c | 5 + arch/x86/include/asm/hardirq.h | 1 + arch/x86/include/asm/idtentry.h | 1 + arch/x86/include/asm/irq.h | 2 +- arch/x86/include/asm/irq_vectors.h | 5 +- arch/x86/include/asm/kvm-x86-pmu-ops.h | 2 + arch/x86/include/asm/kvm_host.h | 10 + arch/x86/include/asm/msr-index.h | 18 +- arch/x86/include/asm/perf_event.h | 1 + arch/x86/include/asm/vmx.h | 1 + arch/x86/kernel/idt.c | 1 + arch/x86/kernel/irq.c | 39 +- arch/x86/kvm/cpuid.c | 15 + arch/x86/kvm/pmu.c | 254 ++++++++- arch/x86/kvm/pmu.h | 45 ++ arch/x86/kvm/svm/pmu.c | 148 ++++- arch/x86/kvm/svm/svm.c | 26 + arch/x86/kvm/svm/svm.h | 2 +- arch/x86/kvm/vmx/capabilities.h | 11 +- arch/x86/kvm/vmx/nested.c | 68 ++- arch/x86/kvm/vmx/pmu_intel.c | 224 ++++++-- arch/x86/kvm/vmx/vmx.c | 89 +-- arch/x86/kvm/vmx/vmx.h | 11 +- arch/x86/kvm/x86.c | 63 ++- arch/x86/kvm/x86.h | 2 + include/linux/perf_event.h | 47 +- kernel/events/core.c | 519 ++++++++++++++---- .../beauty/arch/x86/include/asm/irq_vectors.h | 5 +- .../selftests/kvm/include/kvm_test_harness.h | 13 + .../testing/selftests/kvm/include/kvm_util.h | 3 + .../selftests/kvm/include/x86/processor.h | 8 + tools/testing/selftests/kvm/lib/kvm_util.c | 23 + .../selftests/kvm/x86/pmu_counters_test.c | 24 +- .../selftests/kvm/x86/pmu_event_filter_test.c | 8 +- .../selftests/kvm/x86/vmx_pmu_caps_test.c | 2 +- 37 files changed, 1480 insertions(+), 258 deletions(-) base-commit: 0ad2507d5d93f39619fc42372c347d6006b64319 -- 2.49.0.395.g12beb8f557-goog

1 hour

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[PATCH net 1/2] net: mscc: ocelot: delete PVID VLAN when readding it as non-PVID

by Vladimir Oltean

The following set of commands: ip link add br0 type bridge vlan_filtering 1 # vlan_default_pvid 1 is implicit ip link set swp0 master br0 bridge vlan add dev swp0 vid 1 should result in the dropping of untagged and 802.1p-tagged traffic, but we see that it continues to be accepted. Whereas, had we deleted VID 1 instead, the aforementioned dropping would have worked This is because the ANA_PORT_DROP_CFG update logic doesn't run, because ocelot_vlan_add() only calls ocelot_port_set_pvid() if the new VLAN has the BRIDGE_VLAN_INFO_PVID flag. Similar to other drivers like mt7530_port_vlan_add() which handle this case correctly, we need to test whether the VLAN we're changing used to have the BRIDGE_VLAN_INFO_PVID flag, but lost it now. That amounts to a PVID deletion and should be treated as such. Regarding blame attribution: this never worked properly since the introduction of bridge VLAN filtering in commit 7142529f1688 ("net: mscc: ocelot: add VLAN filtering"). However, there was a significant paradigm shift which aligned the ANA_PORT_DROP_CFG register with the PVID concept rather than with the native VLAN concept, and that change wasn't targeted for 'stable'. Realistically, that is as far as this fix needs to be propagated to. Fixes: be0576fed6d3 ("net: mscc: ocelot: move the logic to drop 802.1p traffic to the pvid deletion") Signed-off-by: Vladimir Oltean <vladimir.oltean(a)nxp.com> --- drivers/net/ethernet/mscc/ocelot.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/net/ethernet/mscc/ocelot.c b/drivers/net/ethernet/mscc/ocelot.c index ef93df520887..08bee56aea35 100644 --- a/drivers/net/ethernet/mscc/ocelot.c +++ b/drivers/net/ethernet/mscc/ocelot.c @@ -830,6 +830,7 @@ EXPORT_SYMBOL(ocelot_vlan_prepare); int ocelot_vlan_add(struct ocelot *ocelot, int port, u16 vid, bool pvid, bool untagged) { + struct ocelot_port *ocelot_port = ocelot->ports[port]; int err; /* Ignore VID 0 added to our RX filter by the 8021q module, since @@ -849,6 +850,11 @@ int ocelot_vlan_add(struct ocelot *ocelot, int port, u16 vid, bool pvid, ocelot_bridge_vlan_find(ocelot, vid)); if (err) return err; + } else if (ocelot_port->pvid_vlan && + ocelot_bridge_vlan_find(ocelot, vid) == ocelot_port->pvid_vlan) { + err = ocelot_port_set_pvid(ocelot, port, NULL); + if (err) + return err; } /* Untagged egress vlan clasification */ -- 2.43.0

1 hour, 22 minutes

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[PATCH v12 00/28] riscv control-flow integrity for usermode

by Deepak Gupta

Basics and overview =================== Software with larger attack surfaces (e.g. network facing apps like databases, browsers or apps relying on browser runtimes) suffer from memory corruption issues which can be utilized by attackers to bend control flow of the program to eventually gain control (by making their payload executable). Attackers are able to perform such attacks by leveraging call-sites which rely on indirect calls or return sites which rely on obtaining return address from stack memory. To mitigate such attacks, risc-v extension zicfilp enforces that all indirect calls must land on a landing pad instruction `lpad` else cpu will raise software check exception (a new cpu exception cause code on riscv). Similarly for return flow, risc-v extension zicfiss extends architecture with - `sspush` instruction to push return address on a shadow stack - `sspopchk` instruction to pop return address from shadow stack and compare with input operand (i.e. return address on stack) - `sspopchk` to raise software check exception if comparision above was a mismatch - Protection mechanism using which shadow stack is not writeable via regular store instructions More information an details can be found at extensions github repo [1]. Equivalent to landing pad (zicfilp) on x86 is `ENDBRANCH` instruction in Intel CET [3] and branch target identification (BTI) [4] on arm. Similarly x86's Intel CET has shadow stack [5] and arm64 has guarded control stack (GCS) [6] which are very similar to risc-v's zicfiss shadow stack. x86 and arm64 support for user mode shadow stack is already in mainline. Kernel awareness for user control flow integrity ================================================ This series picks up Samuel Holland's envcfg changes [2] as well. So if those are being applied independently, they should be removed from this series. Enabling: In order to maintain compatibility and not break anything in user mode, kernel doesn't enable control flow integrity cpu extensions on binary by default. Instead exposes a prctl interface to enable, disable and lock the shadow stack or landing pad feature for a task. This allows userspace (loader) to enumerate if all objects in its address space are compiled with shadow stack and landing pad support and accordingly enable the feature. Additionally if a subsequent `dlopen` happens on a library, user mode can take a decision again to disable the feature (if incoming library is not compiled with support) OR terminate the task (if user mode policy is strict to have all objects in address space to be compiled with control flow integirty cpu feature). prctl to enable shadow stack results in allocating shadow stack from virtual memory and activating for user address space. x86 and arm64 are also following same direction due to similar reason(s). clone/fork: On clone and fork, cfi state for task is inherited by child. Shadow stack is part of virtual memory and is a writeable memory from kernel perspective (writeable via a restricted set of instructions aka shadow stack instructions) Thus kernel changes ensure that this memory is converted into read-only when fork/clone happens and COWed when fault is taken due to sspush, sspopchk or ssamoswap. In case `CLONE_VM` is specified and shadow stack is to be enabled, kernel will automatically allocate a shadow stack for that clone call. map_shadow_stack: x86 introduced `map_shadow_stack` system call to allow user space to explicitly map shadow stack memory in its address space. It is useful to allocate shadow for different contexts managed by a single thread (green threads or contexts) risc-v implements this system call as well. signal management: If shadow stack is enabled for a task, kernel performs an asynchronous control flow diversion to deliver the signal and eventually expects userspace to issue sigreturn so that original execution can be resumed. Even though resume context is prepared by kernel, it is in user space memory and is subject to memory corruption and corruption bugs can be utilized by attacker in this race window to perform arbitrary sigreturn and eventually bypass cfi mechanism. Another issue is how to ensure that cfi related state on sigcontext area is not trampled by legacy apps or apps compiled with old kernel headers. In order to mitigate control-flow hijacting, kernel prepares a token and place it on shadow stack before signal delivery and places address of token in sigcontext structure. During sigreturn, kernel obtains address of token from sigcontext struture, reads token from shadow stack and validates it and only then allow sigreturn to succeed. Compatiblity issue is solved by adopting dynamic sigcontext management introduced for vector extension. This series re-factor the code little bit to allow future sigcontext management easy (as proposed by Andy Chiu from SiFive) config and compilation: Introduce a new risc-v config option `CONFIG_RISCV_USER_CFI`. Selecting this config option picks the kernel support for user control flow integrity. This optin is presented only if toolchain has shadow stack and landing pad support. And is on purpose guarded by toolchain support. Reason being that eventually vDSO also needs to be compiled in with shadow stack and landing pad support. vDSO compile patches are not included as of now because landing pad labeling scheme is yet to settle for usermode runtime. To get more information on kernel interactions with respect to zicfilp and zicfiss, patch series adds documentation for `zicfilp` and `zicfiss` in following: Documentation/arch/riscv/zicfiss.rst Documentation/arch/riscv/zicfilp.rst How to test this series ======================= Toolchain --------- $ git clone git@github.com:sifive/riscv-gnu-toolchain.git -b cfi-dev $ riscv-gnu-toolchain/configure --prefix=<path-to-where-to-build> --with-arch=rv64gc_zicfilp_zicfiss --enable-linux --disable-gdb --with-extra-multilib-test="rv64gc_zicfilp_zicfiss-lp64d:-static" $ make -j$(nproc) Qemu ---- Get the lastest qemu $ cd qemu $ mkdir build $ cd build $ ../configure --target-list=riscv64-softmmu $ make -j$(nproc) Opensbi ------- $ git clone git@github.com:deepak0414/opensbi.git -b v6_cfi_spec_split_opensbi $ make CROSS_COMPILE=<your riscv toolchain> -j$(nproc) PLATFORM=generic Linux ----- Running defconfig is fine. CFI is enabled by default if the toolchain supports it. $ make ARCH=riscv CROSS_COMPILE=<path-to-cfi-riscv-gnu-toolchain>/build/bin/riscv64-unknown-linux-gnu- -j$(nproc) defconfig $ make ARCH=riscv CROSS_COMPILE=<path-to-cfi-riscv-gnu-toolchain>/build/bin/riscv64-unknown-linux-gnu- -j$(nproc) In case you're building your own rootfs using toolchain, please make sure you pick following patch to ensure that vDSO compiled with lpad and shadow stack. "arch/riscv: compile vdso with landing pad" Branch where above patch can be picked https://github.com/deepak0414/linux-riscv-cfi/tree/vdso_user_cfi_v6.12-rc1 Running ------- Modify your qemu command to have: -bios <path-to-cfi-opensbi>/build/platform/generic/firmware/fw_dynamic.bin -cpu rv64,zicfilp=true,zicfiss=true,zimop=true,zcmop=true vDSO related Opens (in the flux) ================================= I am listing these opens for laying out plan and what to expect in future patch sets. And of course for the sake of discussion. Shadow stack and landing pad enabling in vDSO ---------------------------------------------- vDSO must have shadow stack and landing pad support compiled in for task to have shadow stack and landing pad support. This patch series doesn't enable that (yet). Enabling shadow stack support in vDSO should be straight forward (intend to do that in next versions of patch set). Enabling landing pad support in vDSO requires some collaboration with toolchain folks to follow a single label scheme for all object binaries. This is necessary to ensure that all indirect call-sites are setting correct label and target landing pads are decorated with same label scheme. How many vDSOs --------------- Shadow stack instructions are carved out of zimop (may be operations) and if CPU doesn't implement zimop, they're illegal instructions. Kernel could be running on a CPU which may or may not implement zimop. And thus kernel will have to carry 2 different vDSOs and expose the appropriate one depending on whether CPU implements zimop or not. References ========== [1] - https://github.com/riscv/riscv-cfi [2] - https://lore.kernel.org/all/20240814081126.956287-1-samuel.holland@sifive.c… [3] - https://lwn.net/Articles/889475/ [4] - https://developer.arm.com/documentation/109576/0100/Branch-Target-Identific… [5] - https://www.intel.com/content/dam/develop/external/us/en/documents/catc17-i… [6] - https://lwn.net/Articles/940403/ --- changelog --------- v12: - It seems like I had accidently squashed arch agnostic indirect branch tracking prctl and riscv implementation of those prctls. Split them again. - set_shstk_status/set_indir_lp_status perform CSR writes only when CPU support is available. As suggested by Zong Li. - Some minor clean up in kselftests as suggested by Zong Li. v11: - patch "arch/riscv: compile vdso with landing pad" was unconditionally selecting `_zicfilp` for vDSO compile. fixed that. Changed `lpad 1` to to `lpad 0`. v10: - dropped "mm: helper `is_shadow_stack_vma` to check shadow stack vma". This patch is not that interesting to this patch series for risc-v. There are instances in arch directories where VM_SHADOW_STACK flag is anyways used. Dropping this patch to expedite merging in riscv tree. - Took suggestions from `Clement` on "riscv: zicfiss / zicfilp enumeration" to validate presence of cfi based on config. - Added a patch for vDSO to have `lpad 0`. I had omitted this earlier to make sure we add single vdso object with cfi enabled. But a vdso object with scheme of zero labeled landing pad is least common denominator and should work with all objects of zero labeled as well as function-signature labeled objects. v9: - rebased on master (39a803b754d5 fix braino in "9p: fix ->rename_sem exclusion") - dropped "mm: Introduce ARCH_HAS_USER_SHADOW_STACK" (master has it from arm64/gcs) - dropped "prctl: arch-agnostic prctl for shadow stack" (master has it from arm64/gcs) v8: - rebased on palmer/for-next - dropped samuel holland's `envcfg` context switch patches. they are in parlmer/for-next v7: - Removed "riscv/Kconfig: enable HAVE_EXIT_THREAD for riscv" Instead using `deactivate_mm` flow to clean up. see here for more context https://lore.kernel.org/all/20230908203655.543765-1-rick.p.edgecombe@intel.… - Changed the header include in `kselftest`. Hopefully this fixes compile issue faced by Zong Li at SiFive. - Cleaned up an orphaned change to `mm/mmap.c` in below patch "riscv/mm : ensure PROT_WRITE leads to VM_READ | VM_WRITE" - Lock interfaces for shadow stack and indirect branch tracking expect arg == 0 Any future evolution of this interface should accordingly define how arg should be setup. - `mm/map.c` has an instance of using `VM_SHADOW_STACK`. Fixed it to use helper `is_shadow_stack_vma`. - Link to v6: https://lore.kernel.org/r/20241008-v5_user_cfi_series-v6-0-60d9fe073f37@riv… v6: - Picked up Samuel Holland's changes as is with `envcfg` placed in `thread` instead of `thread_info` - fixed unaligned newline escapes in kselftest - cleaned up messages in kselftest and included test output in commit message - fixed a bug in clone path reported by Zong Li - fixed a build issue if CONFIG_RISCV_ISA_V is not selected (this was introduced due to re-factoring signal context management code) v5: - rebased on v6.12-rc1 - Fixed schema related issues in device tree file - Fixed some of the documentation related issues in zicfilp/ss.rst (style issues and added index) - added `SHADOW_STACK_SET_MARKER` so that implementation can define base of shadow stack. - Fixed warnings on definitions added in usercfi.h when CONFIG_RISCV_USER_CFI is not selected. - Adopted context header based signal handling as proposed by Andy Chiu - Added support for enabling kernel mode access to shadow stack using FWFT (https://github.com/riscv-non-isa/riscv-sbi-doc/blob/master/src/ext-firmware…) - Link to v5: https://lore.kernel.org/r/20241001-v5_user_cfi_series-v1-0-3ba65b6e550f@riv… (Note: I had an issue in my workflow due to which version number wasn't picked up correctly while sending out patches) v4: - rebased on 6.11-rc6 - envcfg: Converged with Samuel Holland's patches for envcfg management on per- thread basis. - vma_is_shadow_stack is renamed to is_vma_shadow_stack - picked up Mark Brown's `ARCH_HAS_USER_SHADOW_STACK` patch - signal context: using extended context management to maintain compatibility. - fixed `-Wmissing-prototypes` compiler warnings for prctl functions - Documentation fixes and amending typos. - Link to v4: https://lore.kernel.org/all/20240912231650.3740732-1-debug@rivosinc.com/ v3: - envcfg logic to pick up base envcfg had a bug where `ENVCFG_CBZE` could have been picked on per task basis, even though CPU didn't implement it. Fixed in this series. - dt-bindings As suggested, split into separate commit. fixed the messaging that spec is in public review - arch_is_shadow_stack change arch_is_shadow_stack changed to vma_is_shadow_stack - hwprobe zicfiss / zicfilp if present will get enumerated in hwprobe - selftests As suggested, added object and binary filenames to .gitignore Selftest binary anyways need to be compiled with cfi enabled compiler which will make sure that landing pad and shadow stack are enabled. Thus removed separate enable/disable tests. Cleaned up tests a bit. - Link to v3: https://lore.kernel.org/lkml/20240403234054.2020347-1-debug@rivosinc.com/ v2: - Using config `CONFIG_RISCV_USER_CFI`, kernel support for riscv control flow integrity for user mode programs can be compiled in the kernel. - Enabling of control flow integrity for user programs is left to user runtime - This patch series introduces arch agnostic `prctls` to enable shadow stack and indirect branch tracking. And implements them on riscv. --- --- Changes in v12: - EDITME: describe what is new in this series revision. - EDITME: use bulletpoints and terse descriptions. - Link to v11: https://lore.kernel.org/r/20250310-v5_user_cfi_series-v11-0-86b36cbfb910@ri… Changes in v11: - EDITME: describe what is new in this series revision. - EDITME: use bulletpoints and terse descriptions. - Link to v10: https://lore.kernel.org/r/20250210-v5_user_cfi_series-v10-0-163dcfa31c60@ri… --- Andy Chiu (1): riscv: signal: abstract header saving for setup_sigcontext Clément Léger (1): riscv: Add Firmware Feature SBI extensions definitions Deepak Gupta (25): mm: VM_SHADOW_STACK definition for riscv dt-bindings: riscv: zicfilp and zicfiss in dt-bindings (extensions.yaml) riscv: zicfiss / zicfilp enumeration riscv: zicfiss / zicfilp extension csr and bit definitions riscv: usercfi state for task and save/restore of CSR_SSP on trap entry/exit riscv/mm : ensure PROT_WRITE leads to VM_READ | VM_WRITE riscv mm: manufacture shadow stack pte riscv mmu: teach pte_mkwrite to manufacture shadow stack PTEs riscv mmu: write protect and shadow stack riscv/mm: Implement map_shadow_stack() syscall riscv/shstk: If needed allocate a new shadow stack on clone riscv: Implements arch agnostic shadow stack prctls prctl: arch-agnostic prctl for indirect branch tracking riscv: Implements arch agnostic indirect branch tracking prctls riscv/traps: Introduce software check exception riscv/signal: save and restore of shadow stack for signal riscv/kernel: update __show_regs to print shadow stack register riscv/ptrace: riscv cfi status and state via ptrace and in core files riscv/hwprobe: zicfilp / zicfiss enumeration in hwprobe riscv: enable kernel access to shadow stack memory via FWFT sbi call riscv: kernel command line option to opt out of user cfi riscv: create a config for shadow stack and landing pad instr support riscv: Documentation for landing pad / indirect branch tracking riscv: Documentation for shadow stack on riscv kselftest/riscv: kselftest for user mode cfi Jim Shu (1): arch/riscv: compile vdso with landing pad Documentation/arch/riscv/index.rst | 2 + Documentation/arch/riscv/zicfilp.rst | 115 +++++ Documentation/arch/riscv/zicfiss.rst | 176 +++++++ .../devicetree/bindings/riscv/extensions.yaml | 14 + arch/riscv/Kconfig | 20 + arch/riscv/Makefile | 5 +- arch/riscv/include/asm/asm-prototypes.h | 1 + arch/riscv/include/asm/assembler.h | 44 ++ arch/riscv/include/asm/cpufeature.h | 13 + arch/riscv/include/asm/csr.h | 16 + arch/riscv/include/asm/entry-common.h | 2 + arch/riscv/include/asm/hwcap.h | 2 + arch/riscv/include/asm/mman.h | 25 + arch/riscv/include/asm/mmu_context.h | 7 + arch/riscv/include/asm/pgtable.h | 30 +- arch/riscv/include/asm/processor.h | 2 + arch/riscv/include/asm/sbi.h | 26 + arch/riscv/include/asm/thread_info.h | 3 + arch/riscv/include/asm/usercfi.h | 89 ++++ arch/riscv/include/asm/vector.h | 3 + arch/riscv/include/uapi/asm/hwprobe.h | 2 + arch/riscv/include/uapi/asm/ptrace.h | 22 + arch/riscv/include/uapi/asm/sigcontext.h | 1 + arch/riscv/kernel/Makefile | 1 + arch/riscv/kernel/asm-offsets.c | 8 + arch/riscv/kernel/cpufeature.c | 13 + arch/riscv/kernel/entry.S | 31 +- arch/riscv/kernel/head.S | 12 + arch/riscv/kernel/process.c | 26 +- arch/riscv/kernel/ptrace.c | 83 ++++ arch/riscv/kernel/signal.c | 142 +++++- arch/riscv/kernel/sys_hwprobe.c | 2 + arch/riscv/kernel/sys_riscv.c | 10 + arch/riscv/kernel/traps.c | 43 ++ arch/riscv/kernel/usercfi.c | 530 +++++++++++++++++++++ arch/riscv/kernel/vdso/Makefile | 12 + arch/riscv/kernel/vdso/flush_icache.S | 4 + arch/riscv/kernel/vdso/getcpu.S | 4 + arch/riscv/kernel/vdso/rt_sigreturn.S | 4 + arch/riscv/kernel/vdso/sys_hwprobe.S | 4 + arch/riscv/mm/init.c | 2 +- arch/riscv/mm/pgtable.c | 17 + include/linux/cpu.h | 4 + include/linux/mm.h | 7 + include/uapi/linux/elf.h | 1 + include/uapi/linux/prctl.h | 27 ++ kernel/sys.c | 30 ++ tools/testing/selftests/riscv/Makefile | 2 +- tools/testing/selftests/riscv/cfi/.gitignore | 3 + tools/testing/selftests/riscv/cfi/Makefile | 10 + tools/testing/selftests/riscv/cfi/cfi_rv_test.h | 82 ++++ tools/testing/selftests/riscv/cfi/riscv_cfi_test.c | 78 +++ tools/testing/selftests/riscv/cfi/shadowstack.c | 385 +++++++++++++++ tools/testing/selftests/riscv/cfi/shadowstack.h | 27 ++ 54 files changed, 2195 insertions(+), 29 deletions(-) --- base-commit: 39a803b754d5224a3522016b564113ee1e4091b2 change-id: 20240930-v5_user_cfi_series-3dc332f8f5b2 -- - debug

3 hours, 14 minutes

5
81
0 0

[PATCH RFC bpf-next 0/4] bpf, arm64: support up to 12 arguments

by Alexis Lothoré (eBPF Foundation)

Hello, this series is a revival of Xu Kuhoai's work to enable larger arguments count for BPF programs on ARM64 ([1]). His initial series received some positive feedback, but lacked some specific case handling around arguments alignment (see AAPCS64 C.14 rule in section 6.8.2, [2]). There as been another attempt from Puranjay Mohan, which was unfortunately missing the same thing ([3]). Since there has been some time between those series and this new one, I chose to send it as a new series rather than a new revision of the existing series. To support the increased argument counts and arguments larger than registers size (eg: structures), the trampoline does the following: - for bpf programs: arguments are retrieved from both registers and the function stack, and pushed in the trampoline stack as an array of u64 to generate the programs context. It is then passed by pointer to the bpf programs - when the trampoline is in charge of calling the original function: it restores the registers content, and generates a new stack layout for the additional arguments that do not fit in registers. This new attempt is based on Xu's series and aims to handle the missing alignment concern raised in the reviews discussions. The main novelties are then around arguments alignments: - the first commit is exposing some new info in the BTF function model passed to the JIT compiler to allow it to deduce the needed alignment when configuring the trampoline stack - the second commit is taken from Xu's series, and received the following modifications: - the calc_aux_args computes an expected alignment for each argument - the calc_aux_args computes two different stack space sizes: the one needed to store the bpf programs context, and the original function stacked arguments (which needs alignment). Those stack sizes are in bytes instead of "slots" - when saving/restoring arguments for bpf program or for the original function, make sure to align the load/store accordingly, when relevant - a few typos fixes and some rewording, raised by the review on the original series - the last commit introduces some explicit tests that ensure that the needed alignment is enforced by the trampoline I marked the series as RFC because it appears that the new tests trigger some failures in CI on x86 and s390, despite the series not touching any code related to those architectures. Some very early investigation/gdb debugging on the x86 side seems to hint that it could be related to the same missing alignment too (based on section 3.2.3 in [4], and so the x86 trampoline would need the same alignment handling ?). For s390 it looks less clear, as all values captured from the bpf test program are set to 0 in the CI output, and I don't have the proper setup yet to check the low level details. I am tempted to isolate those new tests (which were actually useful to spot real issues while tuning the ARM64 trampoline) and add them to the relevant DENYLIST files for x86/s390, but I guess this is not the right direction, so I would gladly take a second opinion on this. [1] https://lore.kernel.org/all/20230917150752.69612-1-xukuohai@huaweicloud.com… [2] https://github.com/ARM-software/abi-aa/blob/main/aapcs64/aapcs64.rst#id82 [3] https://lore.kernel.org/bpf/20240705125336.46820-1-puranjay@kernel.org/ [4] https://refspecs.linuxbase.org/elf/x86_64-abi-0.99.pdf Signed-off-by: Alexis Lothoré (eBPF Foundation) <alexis.lothore(a)bootlin.com> --- Alexis Lothoré (eBPF Foundation) (3): bpf: add struct largest member size in func model bpf/selftests: add tests to validate proper arguments alignment on ARM64 bpf/selftests: enable tracing tests for ARM64 Xu Kuohai (1): bpf, arm64: Support up to 12 function arguments arch/arm64/net/bpf_jit_comp.c | 235 ++++++++++++++++----- include/linux/bpf.h | 1 + kernel/bpf/btf.c | 25 +++ tools/testing/selftests/bpf/DENYLIST.aarch64 | 3 - .../selftests/bpf/prog_tests/tracing_struct.c | 23 ++ tools/testing/selftests/bpf/progs/tracing_struct.c | 10 +- .../selftests/bpf/progs/tracing_struct_many_args.c | 67 ++++++ .../testing/selftests/bpf/test_kmods/bpf_testmod.c | 50 +++++ 8 files changed, 357 insertions(+), 57 deletions(-) --- base-commit: 91e7eb701b4bc389e7ddfd80ef6e82d1a6d2d368 change-id: 20250220-many_args_arm64-8bd3747e6948 Best regards, -- Alexis Lothoré, Bootlin Embedded Linux and Kernel engineering https://bootlin.com

5 hours, 33 minutes

6
19
0 0

[PATCH bpf-next v2] bpf: Allow XDP dev-bound programs to perform XDP_REDIRECT into maps

by Lorenzo Bianconi

In the current implementation if the program is dev-bound to a specific device, it will not be possible to perform XDP_REDIRECT into a DEVMAP or CPUMAP even if the program is running in the driver NAPI context and it is not attached to any map entry. This seems in contrast with the explanation available in bpf_prog_map_compatible routine. Fix the issue introducing __bpf_prog_map_compatible utility routine in order to avoid bpf_prog_is_dev_bound() check running bpf_check_tail_call() at program load time (bpf_prog_select_runtime()). Continue forbidding to attach a dev-bound program to XDP maps (BPF_MAP_TYPE_PROG_ARRAY, BPF_MAP_TYPE_DEVMAP and BPF_MAP_TYPE_CPUMAP). Fixes: 3d76a4d3d4e59 ("bpf: XDP metadata RX kfuncs") Signed-off-by: Lorenzo Bianconi <lorenzo(a)kernel.org> --- Changes in v2: - Introduce __bpf_prog_map_compatible() utility routine in order to skip bpf_prog_is_dev_bound check in bpf_check_tail_call() - Extend xdp_metadata selftest - Link to v1: https://lore.kernel.org/r/20250422-xdp-prog-bound-fix-v1-1-0b581fa186fe@ker… --- kernel/bpf/core.c | 27 +++++++++++++--------- .../selftests/bpf/prog_tests/xdp_metadata.c | 22 +++++++++++++++++- tools/testing/selftests/bpf/progs/xdp_metadata.c | 13 +++++++++++ 3 files changed, 50 insertions(+), 12 deletions(-) diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c index ba6b6118cf504041278d05417c4212d57be6fca0..a3e571688421196c3ceaed62b3b59b62a0258a8c 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -2358,8 +2358,8 @@ static unsigned int __bpf_prog_ret0_warn(const void *ctx, return 0; } -bool bpf_prog_map_compatible(struct bpf_map *map, - const struct bpf_prog *fp) +static bool __bpf_prog_map_compatible(struct bpf_map *map, + const struct bpf_prog *fp) { enum bpf_prog_type prog_type = resolve_prog_type(fp); bool ret; @@ -2368,14 +2368,6 @@ bool bpf_prog_map_compatible(struct bpf_map *map, if (fp->kprobe_override) return false; - /* XDP programs inserted into maps are not guaranteed to run on - * a particular netdev (and can run outside driver context entirely - * in the case of devmap and cpumap). Until device checks - * are implemented, prohibit adding dev-bound programs to program maps. - */ - if (bpf_prog_is_dev_bound(aux)) - return false; - spin_lock(&map->owner.lock); if (!map->owner.type) { /* There's no owner yet where we could check for @@ -2409,6 +2401,19 @@ bool bpf_prog_map_compatible(struct bpf_map *map, return ret; } +bool bpf_prog_map_compatible(struct bpf_map *map, const struct bpf_prog *fp) +{ + /* XDP programs inserted into maps are not guaranteed to run on + * a particular netdev (and can run outside driver context entirely + * in the case of devmap and cpumap). Until device checks + * are implemented, prohibit adding dev-bound programs to program maps. + */ + if (bpf_prog_is_dev_bound(fp->aux)) + return false; + + return __bpf_prog_map_compatible(map, fp); +} + static int bpf_check_tail_call(const struct bpf_prog *fp) { struct bpf_prog_aux *aux = fp->aux; @@ -2421,7 +2426,7 @@ static int bpf_check_tail_call(const struct bpf_prog *fp) if (!map_type_contains_progs(map)) continue; - if (!bpf_prog_map_compatible(map, fp)) { + if (!__bpf_prog_map_compatible(map, fp)) { ret = -EINVAL; goto out; } diff --git a/tools/testing/selftests/bpf/prog_tests/xdp_metadata.c b/tools/testing/selftests/bpf/prog_tests/xdp_metadata.c index 3d47878ef6bfb55c236dc9df2c100fcc449f8de3..19f92affc2daa23fdd869554e7a0475b86350a4f 100644 --- a/tools/testing/selftests/bpf/prog_tests/xdp_metadata.c +++ b/tools/testing/selftests/bpf/prog_tests/xdp_metadata.c @@ -351,9 +351,10 @@ void test_xdp_metadata(void) struct xdp_metadata2 *bpf_obj2 = NULL; struct xdp_metadata *bpf_obj = NULL; struct bpf_program *new_prog, *prog; + struct bpf_devmap_val devmap_e = {}; + struct bpf_map *prog_arr, *devmap; struct nstoken *tok = NULL; __u32 queue_id = QUEUE_ID; - struct bpf_map *prog_arr; struct xsk tx_xsk = {}; struct xsk rx_xsk = {}; __u32 val, key = 0; @@ -409,6 +410,13 @@ void test_xdp_metadata(void) bpf_program__set_ifindex(prog, rx_ifindex); bpf_program__set_flags(prog, BPF_F_XDP_DEV_BOUND_ONLY); + /* Make sure we can load a dev-bound program that performs + * XDP_REDIRECT into a devmap. + */ + new_prog = bpf_object__find_program_by_name(bpf_obj->obj, "redirect"); + bpf_program__set_ifindex(new_prog, rx_ifindex); + bpf_program__set_flags(new_prog, BPF_F_XDP_DEV_BOUND_ONLY); + if (!ASSERT_OK(xdp_metadata__load(bpf_obj), "load skeleton")) goto out; @@ -423,6 +431,18 @@ void test_xdp_metadata(void) "update prog_arr")) goto out; + /* Make sure we can't add dev-bound programs to devmaps. */ + devmap = bpf_object__find_map_by_name(bpf_obj->obj, "dev_map"); + if (!ASSERT_OK_PTR(devmap, "no dev_map found")) + goto out; + + devmap_e.bpf_prog.fd = val; + if (!ASSERT_ERR(bpf_map__update_elem(devmap, &key, sizeof(key), + &devmap_e, sizeof(devmap_e), + BPF_ANY), + "update dev_map")) + goto out; + /* Attach BPF program to RX interface. */ ret = bpf_xdp_attach(rx_ifindex, diff --git a/tools/testing/selftests/bpf/progs/xdp_metadata.c b/tools/testing/selftests/bpf/progs/xdp_metadata.c index 31ca229bb3c0f182483334a4ab0bd204acae20f3..09bb8a038d528cf26c5b314cc927915ac2796bf0 100644 --- a/tools/testing/selftests/bpf/progs/xdp_metadata.c +++ b/tools/testing/selftests/bpf/progs/xdp_metadata.c @@ -19,6 +19,13 @@ struct { __type(value, __u32); } prog_arr SEC(".maps"); +struct { + __uint(type, BPF_MAP_TYPE_DEVMAP); + __uint(key_size, sizeof(__u32)); + __uint(value_size, sizeof(struct bpf_devmap_val)); + __uint(max_entries, 1); +} dev_map SEC(".maps"); + extern int bpf_xdp_metadata_rx_timestamp(const struct xdp_md *ctx, __u64 *timestamp) __ksym; extern int bpf_xdp_metadata_rx_hash(const struct xdp_md *ctx, __u32 *hash, @@ -95,4 +102,10 @@ int rx(struct xdp_md *ctx) return bpf_redirect_map(&xsk, ctx->rx_queue_index, XDP_PASS); } +SEC("xdp") +int redirect(struct xdp_md *ctx) +{ + return bpf_redirect_map(&dev_map, ctx->rx_queue_index, XDP_PASS); +} + char _license[] SEC("license") = "GPL"; --- base-commit: 5cffad0a5c8f0cc53ce9fe7cff7bc67c3a97c406 change-id: 20250422-xdp-prog-bound-fix-9f30f3e134aa Best regards, -- Lorenzo Bianconi <lorenzo(a)kernel.org>

7 hours, 7 minutes

5
10
0 0

[PATCH v6 00/14] riscv: add SBI FWFT misaligned exception delegation support

by Clément Léger

The SBI Firmware Feature extension allows the S-mode to request some specific features (either hardware or software) to be enabled. This series uses this extension to request misaligned access exception delegation to S-mode in order to let the kernel handle it. It also adds support for the KVM FWFT SBI extension based on the misaligned access handling infrastructure. FWFT SBI extension is part of the SBI V3.0 specifications [1]. It can be tested using the qemu provided at [2] which contains the series from [3]. Upstream kvm-unit-tests can be used inside kvm to tests the correct delegation of misaligned exceptions. Upstream OpenSBI can be used. Note: Since SBI V3.0 is not yet ratified, FWFT extension API is split between interface only and implementation, allowing to pick only the interface which do not have hard dependencies on SBI. The tests can be run using the kselftest from series [4]. $ qemu-system-riscv64 \ -cpu rv64,trap-misaligned-access=true,v=true \ -M virt \ -m 1024M \ -bios fw_dynamic.bin \ -kernel Image ... # ./misaligned TAP version 13 1..23 # Starting 23 tests from 1 test cases. # RUN global.gp_load_lh ... # OK global.gp_load_lh ok 1 global.gp_load_lh # RUN global.gp_load_lhu ... # OK global.gp_load_lhu ok 2 global.gp_load_lhu # RUN global.gp_load_lw ... # OK global.gp_load_lw ok 3 global.gp_load_lw # RUN global.gp_load_lwu ... # OK global.gp_load_lwu ok 4 global.gp_load_lwu # RUN global.gp_load_ld ... # OK global.gp_load_ld ok 5 global.gp_load_ld # RUN global.gp_load_c_lw ... # OK global.gp_load_c_lw ok 6 global.gp_load_c_lw # RUN global.gp_load_c_ld ... # OK global.gp_load_c_ld ok 7 global.gp_load_c_ld # RUN global.gp_load_c_ldsp ... # OK global.gp_load_c_ldsp ok 8 global.gp_load_c_ldsp # RUN global.gp_load_sh ... # OK global.gp_load_sh ok 9 global.gp_load_sh # RUN global.gp_load_sw ... # OK global.gp_load_sw ok 10 global.gp_load_sw # RUN global.gp_load_sd ... # OK global.gp_load_sd ok 11 global.gp_load_sd # RUN global.gp_load_c_sw ... # OK global.gp_load_c_sw ok 12 global.gp_load_c_sw # RUN global.gp_load_c_sd ... # OK global.gp_load_c_sd ok 13 global.gp_load_c_sd # RUN global.gp_load_c_sdsp ... # OK global.gp_load_c_sdsp ok 14 global.gp_load_c_sdsp # RUN global.fpu_load_flw ... # OK global.fpu_load_flw ok 15 global.fpu_load_flw # RUN global.fpu_load_fld ... # OK global.fpu_load_fld ok 16 global.fpu_load_fld # RUN global.fpu_load_c_fld ... # OK global.fpu_load_c_fld ok 17 global.fpu_load_c_fld # RUN global.fpu_load_c_fldsp ... # OK global.fpu_load_c_fldsp ok 18 global.fpu_load_c_fldsp # RUN global.fpu_store_fsw ... # OK global.fpu_store_fsw ok 19 global.fpu_store_fsw # RUN global.fpu_store_fsd ... # OK global.fpu_store_fsd ok 20 global.fpu_store_fsd # RUN global.fpu_store_c_fsd ... # OK global.fpu_store_c_fsd ok 21 global.fpu_store_c_fsd # RUN global.fpu_store_c_fsdsp ... # OK global.fpu_store_c_fsdsp ok 22 global.fpu_store_c_fsdsp # RUN global.gen_sigbus ... [12797.988647] misaligned[618]: unhandled signal 7 code 0x1 at 0x0000000000014dc0 in misaligned[4dc0,10000+76000] [12797.988990] CPU: 0 UID: 0 PID: 618 Comm: misaligned Not tainted 6.13.0-rc6-00008-g4ec4468967c9-dirty #51 [12797.989169] Hardware name: riscv-virtio,qemu (DT) [12797.989264] epc : 0000000000014dc0 ra : 0000000000014d00 sp : 00007fffe165d100 [12797.989407] gp : 000000000008f6e8 tp : 0000000000095760 t0 : 0000000000000008 [12797.989544] t1 : 00000000000965d8 t2 : 000000000008e830 s0 : 00007fffe165d160 [12797.989692] s1 : 000000000000001a a0 : 0000000000000000 a1 : 0000000000000002 [12797.989831] a2 : 0000000000000000 a3 : 0000000000000000 a4 : ffffffffdeadbeef [12797.989964] a5 : 000000000008ef61 a6 : 626769735f6e0000 a7 : fffffffffffff000 [12797.990094] s2 : 0000000000000001 s3 : 00007fffe165d838 s4 : 00007fffe165d848 [12797.990238] s5 : 000000000000001a s6 : 0000000000010442 s7 : 0000000000010200 [12797.990391] s8 : 000000000000003a s9 : 0000000000094508 s10: 0000000000000000 [12797.990526] s11: 0000555567460668 t3 : 00007fffe165d070 t4 : 00000000000965d0 [12797.990656] t5 : fefefefefefefeff t6 : 0000000000000073 [12797.990756] status: 0000000200004020 badaddr: 000000000008ef61 cause: 0000000000000006 [12797.990911] Code: 8793 8791 3423 fcf4 3783 fc84 c737 dead 0713 eef7 (c398) 0001 # OK global.gen_sigbus ok 23 global.gen_sigbus # PASSED: 23 / 23 tests passed. # Totals: pass:23 fail:0 xfail:0 xpass:0 skip:0 error:0 With kvm-tools: # lkvm run -k sbi.flat -m 128 Info: # lkvm run -k sbi.flat -m 128 -c 1 --name guest-97 Info: Removed ghost socket file "/root/.lkvm//guest-97.sock". ########################################################################## # kvm-unit-tests ########################################################################## ... [test messages elided] PASS: sbi: fwft: FWFT extension probing no error PASS: sbi: fwft: get/set reserved feature 0x6 error == SBI_ERR_DENIED PASS: sbi: fwft: get/set reserved feature 0x3fffffff error == SBI_ERR_DENIED PASS: sbi: fwft: get/set reserved feature 0x80000000 error == SBI_ERR_DENIED PASS: sbi: fwft: get/set reserved feature 0xbfffffff error == SBI_ERR_DENIED PASS: sbi: fwft: misaligned_deleg: Get misaligned deleg feature no error PASS: sbi: fwft: misaligned_deleg: Set misaligned deleg feature invalid value error PASS: sbi: fwft: misaligned_deleg: Set misaligned deleg feature invalid value error PASS: sbi: fwft: misaligned_deleg: Set misaligned deleg feature value no error PASS: sbi: fwft: misaligned_deleg: Set misaligned deleg feature value 0 PASS: sbi: fwft: misaligned_deleg: Set misaligned deleg feature value no error PASS: sbi: fwft: misaligned_deleg: Set misaligned deleg feature value 1 PASS: sbi: fwft: misaligned_deleg: Verify misaligned load exception trap in supervisor SUMMARY: 50 tests, 2 unexpected failures, 12 skipped This series is available at [5]. Link: https://github.com/riscv-non-isa/riscv-sbi-doc/releases/download/vv3.0-rc2/… [1] Link: https://github.com/rivosinc/qemu/tree/dev/cleger/misaligned [2] Link: https://lore.kernel.org/all/20241211211933.198792-3-fkonrad@amd.com/T/ [3] Link: https://lore.kernel.org/linux-riscv/20250414123543.1615478-1-cleger@rivosin… [4] Link: https://github.com/rivosinc/linux/tree/dev/cleger/fwft [5] --- V6: - Rename FWFT interface to remove "_local" - Fix test for MEDELEG values in KVM FWFT support - Add __init for unaligned_access_init() - Rebased on master V5: - Return ERANGE as mapping for SBI_ERR_BAD_RANGE - Removed unused sbi_fwft_get() - Fix kernel for sbi_fwft_local_set_cpumask() - Fix indentation for sbi_fwft_local_set() - Remove spurious space in kvm_sbi_fwft_ops. - Rebased on origin/master - Remove fixes commits and sent them as a separate series [4] V4: - Check SBI version 3.0 instead of 2.0 for FWFT presence - Use long for kvm_sbi_fwft operation return value - Init KVM sbi extension even if default_disabled - Remove revert_on_fail parameter for sbi_fwft_feature_set(). - Fix comments for sbi_fwft_set/get() - Only handle local features (there are no globals yet in the spec) - Add new SBI errors to sbi_err_map_linux_errno() V3: - Added comment about kvm sbi fwft supported/set/get callback requirements - Move struct kvm_sbi_fwft_feature in kvm_sbi_fwft.c - Add a FWFT interface V2: - Added Kselftest for misaligned testing - Added get_user() usage instead of __get_user() - Reenable interrupt when possible in misaligned access handling - Document that riscv supports unaligned-traps - Fix KVM extension state when an init function is present - Rework SBI misaligned accesses trap delegation code - Added support for CPU hotplugging - Added KVM SBI reset callback - Added reset for KVM SBI FWFT lock - Return SBI_ERR_DENIED_LOCKED when LOCK flag is set Clément Léger (14): riscv: sbi: add Firmware Feature (FWFT) SBI extensions definitions riscv: sbi: remove useless parenthesis riscv: sbi: add new SBI error mappings riscv: sbi: add FWFT extension interface riscv: sbi: add SBI FWFT extension calls riscv: misaligned: request misaligned exception from SBI riscv: misaligned: use on_each_cpu() for scalar misaligned access probing riscv: misaligned: use correct CONFIG_ ifdef for misaligned_access_speed riscv: misaligned: move emulated access uniformity check in a function riscv: misaligned: add a function to check misalign trap delegability RISC-V: KVM: add SBI extension init()/deinit() functions RISC-V: KVM: add SBI extension reset callback RISC-V: KVM: add support for FWFT SBI extension RISC-V: KVM: add support for SBI_FWFT_MISALIGNED_DELEG arch/riscv/include/asm/cpufeature.h | 8 +- arch/riscv/include/asm/kvm_host.h | 5 +- arch/riscv/include/asm/kvm_vcpu_sbi.h | 12 + arch/riscv/include/asm/kvm_vcpu_sbi_fwft.h | 29 +++ arch/riscv/include/asm/sbi.h | 60 +++++ arch/riscv/include/uapi/asm/kvm.h | 1 + arch/riscv/kernel/sbi.c | 81 ++++++- arch/riscv/kernel/traps_misaligned.c | 110 ++++++++- arch/riscv/kernel/unaligned_access_speed.c | 8 +- arch/riscv/kvm/Makefile | 1 + arch/riscv/kvm/vcpu.c | 7 +- arch/riscv/kvm/vcpu_sbi.c | 54 +++++ arch/riscv/kvm/vcpu_sbi_fwft.c | 252 +++++++++++++++++++++ arch/riscv/kvm/vcpu_sbi_sta.c | 3 +- 14 files changed, 613 insertions(+), 18 deletions(-) create mode 100644 arch/riscv/include/asm/kvm_vcpu_sbi_fwft.h create mode 100644 arch/riscv/kvm/vcpu_sbi_fwft.c -- 2.49.0

7 hours, 10 minutes

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[PATCH bpf-next v1 0/2] ktls, sockmap: Fix missing uncharge operation and add selfttest

by Jiayuan Chen

Cong reported a warning when running ./test_sockmp: https://lore.kernel.org/bpf/aAmIi0vlycHtbXeb@pop-os.localdomain/T/#t ------------[ cut here ]------------ WARNING: CPU: 1 PID: 40 at net/ipv4/af_inet.c inet_sock_destruct+0x173/0x1d5 Tainted: [W]=WARN Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.15.0-1 04/01/2014 Workqueue: events sk_psock_destroy RIP: 0010:inet_sock_destruct+0x173/0x1d5 RSP: 0018:ffff8880085cfc18 EFLAGS: 00010202 RAX: 1ffff11003dbfc00 RBX: ffff88801edfe3e8 RCX: ffffffff822f5af4 RDX: 0000000000000007 RSI: dffffc0000000000 RDI: ffff88801edfe16c RBP: ffff88801edfe184 R08: ffffed1003dbfc31 R09: 0000000000000000 R10: ffffffff822f5ab7 R11: ffff88801edfe187 R12: ffff88801edfdec0 R13: ffff888020376ac0 R14: ffff888020376ac0 R15: ffff888020376a60 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000556365155830 CR3: 000000001d6aa000 CR4: 0000000000350ef0 Call Trace: <TASK> __sk_destruct+0x46/0x222 sk_psock_destroy+0x22f/0x242 process_one_work+0x504/0x8a8 ? process_one_work+0x39d/0x8a8 ? __pfx_process_one_work+0x10/0x10 ? worker_thread+0x44/0x2ae ? __list_add_valid_or_report+0x83/0xea ? srso_return_thunk+0x5/0x5f ? __list_add+0x45/0x52 process_scheduled_works+0x73/0x82 worker_thread+0x1ce/0x2ae When we specify apply_bytes, we divide the msg into multiple segments, each with a length of 'send', and every time we send this part of the data using tcp_bpf_sendmsg_redir(), we use sk_msg_return_zero() to uncharge the memory of the specified 'send' size. However, if the first segment of data fails to send, for example, the peer's buffer is full, we need to release all of the msg. When releasing the msg, we haven't uncharged the memory of the subsequent segments. This modification does not make significant logical changes, but only fills in the missing uncharge places. This issue has existed all along, until it was exposed after we added the apply test in test_sockmap: commit 3448ad23b34e ("selftests/bpf: Add apply_bytes test to test_txmsg_redir_wait_sndmem in test_sockmap") Jiayuan Chen (2): ktls, sockmap: Fix missing uncharge operation selftests/bpf: Add test to cover sockmap with ktls net/tls/tls_sw.c | 7 ++ .../selftests/bpf/prog_tests/sockmap_ktls.c | 76 +++++++++++++++++++ .../selftests/bpf/progs/test_sockmap_ktls.c | 10 +++ 3 files changed, 93 insertions(+) -- 2.47.1

8 hours, 57 minutes

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[RFC PATCH 00/39] 1G page support for guest_memfd

by Ackerley Tng

Hello, This patchset is our exploration of how to support 1G pages in guest_memfd, and how the pages will be used in Confidential VMs. The patchset covers: + How to get 1G pages + Allowing mmap() of guest_memfd to userspace so that both private and shared memory can use the same physical pages + Splitting and reconstructing pages to support conversions and mmap() + How the VM, userspace and guest_memfd interact to support conversions + Selftests to test all the above + Selftests also demonstrate the conversion flow between VM, userspace and guest_memfd. Why 1G pages in guest memfd? Bring guest_memfd to performance and memory savings parity with VMs that are backed by HugeTLBfs. + Performance is improved with 1G pages by more TLB hits and faster page walks on TLB misses. + Memory savings from 1G pages comes from HugeTLB Vmemmap Optimization (HVO). Options for 1G page support: 1. HugeTLB 2. Contiguous Memory Allocator (CMA) 3. Other suggestions are welcome! Comparison between options: 1. HugeTLB + Refactor HugeTLB to separate allocator from the rest of HugeTLB + Pro: Graceful transition for VMs backed with HugeTLB to guest_memfd + Near term: Allows co-tenancy of HugeTLB and guest_memfd backed VMs + Pro: Can provide iterative steps toward new future allocator + Unexplored: Managing userspace-visible changes + e.g. HugeTLB's free_hugepages will decrease if HugeTLB is used, but not when future allocator is used 2. CMA + Port some HugeTLB features to be applied on CMA + Pro: Clean slate What would refactoring HugeTLB involve? (Some refactoring was done in this RFC, more can be done.) 1. Broadly involves separating the HugeTLB allocator from the rest of HugeTLB + Brings more modularity to HugeTLB + No functionality change intended + Likely step towards HugeTLB's integration into core-mm 2. guest_memfd will use just the allocator component of HugeTLB, not including the complex parts of HugeTLB like + Userspace reservations (resv_map) + Shared PMD mappings + Special page walkers What features would need to be ported to CMA? + Improved allocation guarantees + Per NUMA node pool of huge pages + Subpools per guest_memfd + Memory savings + Something like HugeTLB Vmemmap Optimization + Configuration/reporting features + Configuration of number of pages available (and per NUMA node) at and after host boot + Reporting of memory usage/availability statistics at runtime HugeTLB was picked as the source of 1G pages for this RFC because it allows a graceful transition, and retains memory savings from HVO. To illustrate this, if a host machine uses HugeTLBfs to back VMs, and a confidential VM were to be scheduled on that host, some HugeTLBfs pages would have to be given up and returned to CMA for guest_memfd pages to be rebuilt from that memory. This requires memory to be reserved for HVO to be removed and reapplied on the new guest_memfd memory. This not only slows down memory allocation but also trims the benefits of HVO. Memory would have to be reserved on the host to facilitate these transitions. Improving how guest_memfd uses the allocator in a future revision of this RFC: To provide an easier transition away from HugeTLB, guest_memfd's use of HugeTLB should be limited to these allocator functions: + reserve(node, page_size, num_pages) => opaque handle + Used when a guest_memfd inode is created to reserve memory from backend allocator + allocate(handle, mempolicy, page_size) => folio + To allocate a folio from guest_memfd's reservation + split(handle, folio, target_page_size) => void + To take a huge folio, and split it to smaller folios, restore to filemap + reconstruct(handle, first_folio, nr_pages) => void + To take a folio, and reconstruct a huge folio out of nr_pages from the first_folio + free(handle, folio) => void + To return folio to guest_memfd's reservation + error(handle, folio) => void + To handle memory errors + unreserve(handle) => void + To return guest_memfd's reservation to allocator backend Userspace should only provide a page size when creating a guest_memfd and should not have to specify HugeTLB. Overview of patches: + Patches 01-12 + Many small changes to HugeTLB, mostly to separate HugeTLBfs concepts from HugeTLB, and to expose HugeTLB functions. + Patches 13-16 + Letting guest_memfd use HugeTLB + Creation of each guest_memfd reserves pages from HugeTLB's global hstate and puts it into the guest_memfd inode's subpool + Each folio allocation takes a page from the guest_memfd inode's subpool + Patches 17-21 + Selftests for new HugeTLB features in guest_memfd + Patches 22-24 + More small changes on the HugeTLB side to expose functions needed by guest_memfd + Patch 25: + Uses the newly available functions from patches 22-24 to split HugeTLB pages. In this patch, HugeTLB folios are always split to 4K before any usage, private or shared. + Patches 26-28 + Allow mmap() in guest_memfd and faulting in shared pages + Patch 29 + Enables conversion between private/shared pages + Patch 30 + Required to zero folios after conversions to avoid leaking initialized kernel memory + Patch 31-38 + Add selftests to test mapping pages to userspace, guest/host memory sharing and update conversions tests + Patch 33 illustrates the conversion flow between VM/userspace/guest_memfd + Patch 39 + Dynamically split and reconstruct HugeTLB pages instead of always splitting before use. All earlier selftests are expected to still pass. TODOs: + Add logic to wait for safe_refcount [1] + Look into lazy splitting/reconstruction of pages + Currently, when the KVM_SET_MEMORY_ATTRIBUTES is invoked, not only is the mem_attr_array and faultability updated, the pages in the requested range are also split/reconstructed as necessary. We want to look into delaying splitting/reconstruction to fault time. + Solve race between folios being faulted in and being truncated + When running private_mem_conversions_test with more than 1 vCPU, a folio getting truncated may get faulted in by another process, causing elevated mapcounts when the folio is freed (VM_BUG_ON_FOLIO). + Add intermediate splits (1G should first split to 2M and not split directly to 4K) + Use guest's lock instead of hugetlb_lock + Use multi-index xarray/replace xarray with some other data struct for faultability flag + Refactor HugeTLB better, present generic allocator interface Please let us know your thoughts on: + HugeTLB as the choice of transitional allocator backend + Refactoring HugeTLB to provide generic allocator interface + Shared/private conversion flow + Requiring user to request kernel to unmap pages from userspace using madvise(MADV_DONTNEED) + Failing conversion on elevated mapcounts/pincounts/refcounts + Process of splitting/reconstructing page + Anything else! [1] https://lore.kernel.org/all/20240829-guest-memfd-lib-v2-0-b9afc1ff3656@quic… Ackerley Tng (37): mm: hugetlb: Simplify logic in dequeue_hugetlb_folio_vma() mm: hugetlb: Refactor vma_has_reserves() to should_use_hstate_resv() mm: hugetlb: Remove unnecessary check for avoid_reserve mm: mempolicy: Refactor out policy_node_nodemask() mm: hugetlb: Refactor alloc_buddy_hugetlb_folio_with_mpol() to interpret mempolicy instead of vma mm: hugetlb: Refactor dequeue_hugetlb_folio_vma() to use mpol mm: hugetlb: Refactor out hugetlb_alloc_folio mm: truncate: Expose preparation steps for truncate_inode_pages_final mm: hugetlb: Expose hugetlb_subpool_{get,put}_pages() mm: hugetlb: Add option to create new subpool without using surplus mm: hugetlb: Expose hugetlb_acct_memory() mm: hugetlb: Move and expose hugetlb_zero_partial_page() KVM: guest_memfd: Make guest mem use guest mem inodes instead of anonymous inodes KVM: guest_memfd: hugetlb: initialization and cleanup KVM: guest_memfd: hugetlb: allocate and truncate from hugetlb KVM: guest_memfd: Add page alignment check for hugetlb guest_memfd KVM: selftests: Add basic selftests for hugetlb-backed guest_memfd KVM: selftests: Support various types of backing sources for private memory KVM: selftests: Update test for various private memory backing source types KVM: selftests: Add private_mem_conversions_test.sh KVM: selftests: Test that guest_memfd usage is reported via hugetlb mm: hugetlb: Expose vmemmap optimization functions mm: hugetlb: Expose HugeTLB functions for promoting/demoting pages mm: hugetlb: Add functions to add/move/remove from hugetlb lists KVM: guest_memfd: Track faultability within a struct kvm_gmem_private KVM: guest_memfd: Allow mmapping guest_memfd files KVM: guest_memfd: Use vm_type to determine default faultability KVM: Handle conversions in the SET_MEMORY_ATTRIBUTES ioctl KVM: guest_memfd: Handle folio preparation for guest_memfd mmap KVM: selftests: Allow vm_set_memory_attributes to be used without asserting return value of 0 KVM: selftests: Test using guest_memfd memory from userspace KVM: selftests: Test guest_memfd memory sharing between guest and host KVM: selftests: Add notes in private_mem_kvm_exits_test for mmap-able guest_memfd KVM: selftests: Test that pinned pages block KVM from setting memory attributes to PRIVATE KVM: selftests: Refactor vm_mem_add to be more flexible KVM: selftests: Add helper to perform madvise by memslots KVM: selftests: Update private_mem_conversions_test for mmap()able guest_memfd Vishal Annapurve (2): KVM: guest_memfd: Split HugeTLB pages for guest_memfd use KVM: guest_memfd: Dynamically split/reconstruct HugeTLB page fs/hugetlbfs/inode.c | 35 +- include/linux/hugetlb.h | 54 +- include/linux/kvm_host.h | 1 + include/linux/mempolicy.h | 2 + include/linux/mm.h | 1 + include/uapi/linux/kvm.h | 26 + include/uapi/linux/magic.h | 1 + mm/hugetlb.c | 346 ++-- mm/hugetlb_vmemmap.h | 11 - mm/mempolicy.c | 36 +- mm/truncate.c | 26 +- tools/include/linux/kernel.h | 4 +- tools/testing/selftests/kvm/Makefile | 3 + .../kvm/guest_memfd_hugetlb_reporting_test.c | 222 +++ .../selftests/kvm/guest_memfd_pin_test.c | 104 ++ .../selftests/kvm/guest_memfd_sharing_test.c | 160 ++ .../testing/selftests/kvm/guest_memfd_test.c | 238 ++- .../testing/selftests/kvm/include/kvm_util.h | 45 +- .../testing/selftests/kvm/include/test_util.h | 18 + tools/testing/selftests/kvm/lib/kvm_util.c | 443 +++-- tools/testing/selftests/kvm/lib/test_util.c | 99 ++ .../kvm/x86_64/private_mem_conversions_test.c | 158 +- .../x86_64/private_mem_conversions_test.sh | 91 + .../kvm/x86_64/private_mem_kvm_exits_test.c | 11 +- virt/kvm/guest_memfd.c | 1563 ++++++++++++++++- virt/kvm/kvm_main.c | 17 + virt/kvm/kvm_mm.h | 16 + 27 files changed, 3288 insertions(+), 443 deletions(-) create mode 100644 tools/testing/selftests/kvm/guest_memfd_hugetlb_reporting_test.c create mode 100644 tools/testing/selftests/kvm/guest_memfd_pin_test.c create mode 100644 tools/testing/selftests/kvm/guest_memfd_sharing_test.c create mode 100755 tools/testing/selftests/kvm/x86_64/private_mem_conversions_test.sh -- 2.46.0.598.g6f2099f65c-goog

10 hours, 54 minutes

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Linux-kselftest-mirror April 2025