March 2025 - Linux-kselftest-mirror

[PATCH] selftests/pidfd: align stack to fix SP alignment exception

by Shuai Xue

The pidfd_test fails on the ARM64 platform with the following error: Bail out! pidfd_poll check for premature notification on child thread exec test: Failed When exception-trace is enabled, the kernel logs the details: #echo 1 > /proc/sys/debug/exception-trace #dmesg | tail -n 20 [48628.713023] pidfd_test[1082142]: unhandled exception: SP Alignment, ESR 0x000000009a000000, SP/PC alignment exception in pidfd_test[400000+4000] [48628.713049] CPU: 21 PID: 1082142 Comm: pidfd_test Kdump: loaded Tainted: G W E 6.6.71-3_rc1.al8.aarch64 #1 [48628.713051] Hardware name: AlibabaCloud AliServer-Xuanwu2.0AM-1UC1P-5B/AS1111MG1, BIOS 1.2.M1.AL.P.157.00 07/29/2023 [48628.713053] pstate: 60001800 (nZCv daif -PAN -UAO -TCO -DIT +SSBS BTYPE=-c) [48628.713055] pc : 0000000000402100 [48628.713056] lr : 0000ffff98288f9c [48628.713056] sp : 0000ffffde49daa8 [48628.713057] x29: 0000000000000000 x28: 0000000000000000 x27: 0000000000000000 [48628.713060] x26: 0000000000000000 x25: 0000000000000000 x24: 0000000000000000 [48628.713062] x23: 0000000000000000 x22: 0000000000000000 x21: 0000000000400e80 [48628.713065] x20: 0000000000000000 x19: 0000000000402650 x18: 0000000000000000 [48628.713067] x17: 00000000004200d8 x16: 0000ffff98288f40 x15: 0000ffffde49b92c [48628.713070] x14: 0000000000000000 x13: 0000000000000000 x12: 0000000000000000 [48628.713072] x11: 0000000000001011 x10: 0000000000402100 x9 : 0000000000000010 [48628.713074] x8 : 00000000000000dc x7 : 3861616239346564 x6 : 000000000000000a [48628.713077] x5 : 0000ffffde49daa8 x4 : 000000000000000a x3 : 0000ffffde49daa8 [48628.713079] x2 : 0000ffffde49dadc x1 : 0000ffffde49daa8 x0 : 0000000000000000 According to ARM ARM D1.3.10.2 SP alignment checking: > When the SP is used as the base address of a calculation, regardless of > any offset applied by the instruction, if bits [3:0] of the SP are not > 0b0000, there is a misaligned SP. To fix it, align the stack with 16 bytes. Signed-off-by: Shuai Xue <xueshuai(a)linux.alibaba.com> --- tools/testing/selftests/pidfd/pidfd_test.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/testing/selftests/pidfd/pidfd_test.c b/tools/testing/selftests/pidfd/pidfd_test.c index c081ae91313a..ec161a7c3ff9 100644 --- a/tools/testing/selftests/pidfd/pidfd_test.c +++ b/tools/testing/selftests/pidfd/pidfd_test.c @@ -33,7 +33,7 @@ static bool have_pidfd_send_signal; static pid_t pidfd_clone(int flags, int *pidfd, int (*fn)(void *)) { size_t stack_size = 1024; - char *stack[1024] = { 0 }; + char *stack[1024] __attribute__((aligned(16))) = {0}; #ifdef __ia64__ return __clone2(fn, stack, stack_size, flags | SIGCHLD, NULL, pidfd); -- 2.39.3

2 weeks, 2 days

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[PATCH v2 00/16] selftests: vDSO: parse_vdso: Make compatible with nolibc

by Thomas Weißschuh

For testing the functionality of the vDSO, it is necessary to build userspace programs for multiple different architectures. It is additional work to acquire matching userspace cross-compilers with full C libraries and then building root images out of those. The kernel tree already contains nolibc, a small, header-only C library. By using it, it is possible to build userspace programs without any additional dependencies. For example the kernel.org crosstools or multi-target clang can be used to build test programs for a multitude of architectures. While nolibc is very limited, it is enough for many selftests. With some minor adjustments it is possible to make parse_vdso.c compatible with nolibc. As an example, vdso_standalone_test_x86 is now built from the same C code as the regular vdso_test_gettimeofday, while still being completely standalone. Also drop the dependency of parse_vdso.c on the elf.h header from libc and only use the one from the kernel's UAPI. While this series is useful on its own now, it will also integrate with the kunit UAPI framework currently under development: https://lore.kernel.org/lkml/20250217-kunit-kselftests-v1-0-42b4524c3b0a@li… Signed-off-by: Thomas Weißschuh <thomas.weissschuh(a)linutronix.de> --- Changes in v2: - Provide a limits.h header in nolibc - Pick up Reviewed-by tags from Kees - Link to v1: https://lore.kernel.org/r/20250203-parse_vdso-nolibc-v1-0-9cb6268d77be@linu… --- Thomas Weißschuh (16): MAINTAINERS: Add vDSO selftests elf, uapi: Add definition for STN_UNDEF elf, uapi: Add definition for DT_GNU_HASH elf, uapi: Add definitions for VER_FLG_BASE and VER_FLG_WEAK elf, uapi: Add type ElfXX_Versym elf, uapi: Add types ElfXX_Verdef and ElfXX_Veraux tools/include: Add uapi/linux/elf.h selftests: Add headers target tools/nolibc: add limits.h shim header selftests: vDSO: vdso_standalone_test_x86: Use vdso_init_form_sysinfo_ehdr selftests: vDSO: parse_vdso: Drop vdso_init_from_auxv() selftests: vDSO: parse_vdso: Use UAPI headers instead of libc headers selftests: vDSO: parse_vdso: Test __SIZEOF_LONG__ instead of ULONG_MAX selftests: vDSO: vdso_test_gettimeofday: Clean up includes selftests: vDSO: vdso_test_gettimeofday: Make compatible with nolibc selftests: vDSO: vdso_standalone_test_x86: Switch to nolibc MAINTAINERS | 1 + include/uapi/linux/elf.h | 38 ++ tools/include/nolibc/Makefile | 1 + tools/include/nolibc/limits.h | 7 + tools/include/uapi/linux/elf.h | 524 +++++++++++++++++++++ tools/testing/selftests/lib.mk | 5 +- tools/testing/selftests/vDSO/Makefile | 11 +- tools/testing/selftests/vDSO/parse_vdso.c | 19 +- tools/testing/selftests/vDSO/parse_vdso.h | 1 - .../selftests/vDSO/vdso_standalone_test_x86.c | 143 +----- .../selftests/vDSO/vdso_test_gettimeofday.c | 4 +- 11 files changed, 590 insertions(+), 164 deletions(-) --- base-commit: 2014c95afecee3e76ca4a56956a936e23283f05b change-id: 20241017-parse_vdso-nolibc-e069baa7ff48 Best regards, -- Thomas Weißschuh <thomas.weissschuh(a)linutronix.de>

2 weeks, 4 days

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[PATCH bpf v2 0/2] bpf, xdp: clean adjust_{head,meta} memory when offset < 0

by Jiayuan Chen

This patchset originates from my attempt to resolve a KMSAN warning that has existed for over 3 years: https://syzkaller.appspot.com/bug?extid=0e6ddb1ef80986bdfe64 Previously, we had a brief discussion in this thread about whether we can simply perform memset in adjust_{head,meta}: https://lore.kernel.org/netdev/20250328043941.085de23b@kernel.org/T/#t Unfortunately, I couldn't find a similar topic in the mail list, but I did find a similar security-related commit: commit 6dfb970d3dbd ("xdp: avoid leaking info stored in frame data on page reuse") I just create a new topic here and make subject more clear, we can discuss this here. Meanwhile, I also discovered a related issue that led to a CVE,specifically the Facebook Katran vulnerability (https://vuldb.com/?id.246309). Currently, even with unprivileged functionality disabled, a user can load a BPF program using CAP_BPF and CAP_NET_ADMIN, which I believe we should avoid exposing kernel memory directly to users now. Regarding performance considerations, I added corresponding results to the selftest, testing common MAC headers and IP headers of various sizes. Compared to not using memset, the execution time increased by 2ns, but I think this is negligible considering the entire net stack. Jiayuan Chen (2): bpf, xdp: clean head/meta when expanding it selftests/bpf: add perf test for adjust_{head,meta} include/uapi/linux/bpf.h | 8 +-- net/core/filter.c | 5 +- tools/include/uapi/linux/bpf.h | 6 ++- .../selftests/bpf/prog_tests/xdp_perf.c | 52 ++++++++++++++++--- tools/testing/selftests/bpf/progs/xdp_dummy.c | 14 +++++ 5 files changed, 72 insertions(+), 13 deletions(-) -- 2.47.1

2 weeks, 5 days

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[PATCH bpf-next 00/11] bpf: Mitigate Spectre v1 using barriers

by Luis Gerhorst

This improves the expressiveness of unprivileged BPF by inserting speculation barriers instead of rejecting the programs. The approach was previously presented at LPC'24 [1] and RAID'24 [2]. To mitigate the Spectre v1 (PHT) vulnerability, the kernel rejects potentially-dangerous unprivileged BPF programs as of commit 9183671af6db ("bpf: Fix leakage under speculation on mispredicted branches"). In [2], we have analyzed 364 object files from open source projects (Linux Samples and Selftests, BCC, Loxilb, Cilium, libbpf Examples, Parca, and Prevail) and found that this affects 31% to 54% of programs. To resolve this in the majority of cases this patchset adds a fall-back for mitigating Spectre v1 using speculation barriers. The kernel still optimistically attempts to verify all speculative paths but uses speculation barriers against v1 when unsafe behavior is detected. This allows for more programs to be accepted without disabling the BPF Spectre mitigations (e.g., by setting cpu_mitigations_off()). In [1] we have measured the overhead of this approach relative to having mitigations off and including the upstream Spectre v4 mitigations. For event tracing and stack-sampling profilers, we found that mitigations increase BPF program execution time by 0% to 62%. For the Loxilb network load balancer, we have measured a 14% slowdown in SCTP performance but no significant slowdown for TCP. This overhead only applies to programs that were previously rejected. I reran the expressiveness-evaluation with v6.14 and made sure the main results still match those from [1] and [2] (which used v6.5). Main design decisions are: * Do not use separate bytecode insns for v1 and v4 barriers. This simplifies the verifier significantly and has the only downside that performance on PowerPC is not as high as it could be. * Allow archs to still disable v1/v4 mitigations separately by setting bpf_jit_bypass_spec_v1/v4(). This has the benefit that archs can benefit from improved BPF expressiveness / performance if they are not vulnerable (e.g., ARM64 for v4 in the kernel). * Do not remove the empty BPF_NOSPEC implementation for backends for which it is unknown whether they are vulnerable to Spectre v1. [1] https://lpc.events/event/18/contributions/1954/ ("Mitigating Spectre-PHT using Speculation Barriers in Linux eBPF") [2] https://arxiv.org/pdf/2405.00078 ("VeriFence: Lightweight and Precise Spectre Defenses for Untrusted Linux Kernel Extensions") Changes: * RFC -> v1: - rebase to bpf-next-250313 - tests: mark expected successes/new errors - add bpt_jit_bypass_spec_v1/v4() to avoid #ifdef in bpf_bypass_spec_v1/v4() - ensure that nospec with v1-support is implemented for archs for which GCC supports speculation barriers, except for MIPS - arm64: emit speculation barrier - powerpc: change nospec to include v1 barrier - discuss potential security (archs that do not impl. BPF nospec) and performance (only PowerPC) regressions RFC: https://lore.kernel.org/bpf/20250224203619.594724-1-luis.gerhorst@fau.de/ Luis Gerhorst (11): bpf: Move insn if/else into do_check_insn() bpf: Return -EFAULT on misconfigurations bpf: Return -EFAULT on internal errors bpf, arm64, powerpc: Add bpf_jit_bypass_spec_v1/v4() bpf, arm64, powerpc: Change nospec to include v1 barrier bpf: Rename sanitize_stack_spill to nospec_result bpf: Fall back to nospec for Spectre v1 bpf: Allow nospec-protected var-offset stack access bpf: Return PTR_ERR from push_stack() bpf: Fall back to nospec for sanitization-failures bpf: Fall back to nospec for spec path verification arch/arm64/net/bpf_jit.h | 5 + arch/arm64/net/bpf_jit_comp.c | 28 +- arch/powerpc/net/bpf_jit_comp64.c | 79 +- include/linux/bpf.h | 11 +- include/linux/bpf_verifier.h | 3 +- include/linux/filter.h | 2 +- kernel/bpf/core.c | 32 +- kernel/bpf/verifier.c | 723 ++++++++++-------- .../selftests/bpf/progs/verifier_and.c | 3 +- .../selftests/bpf/progs/verifier_bounds.c | 35 +- .../bpf/progs/verifier_bounds_deduction.c | 43 +- .../selftests/bpf/progs/verifier_map_ptr.c | 12 +- .../selftests/bpf/progs/verifier_movsx.c | 6 +- .../selftests/bpf/progs/verifier_unpriv.c | 3 +- .../bpf/progs/verifier_value_ptr_arith.c | 50 +- .../selftests/bpf/verifier/dead_code.c | 3 +- tools/testing/selftests/bpf/verifier/jmp32.c | 33 +- tools/testing/selftests/bpf/verifier/jset.c | 10 +- 18 files changed, 630 insertions(+), 451 deletions(-) base-commit: 46d38f489ef02175dcff1e03a849c226eb0729a6 -- 2.48.1

2 weeks, 5 days

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[PATCH v8 00/10] Basic SEV-SNP Selftests

by Pratik R. Sampat

This patch series extends the sev_init2 and the sev_smoke test to exercise the SEV-SNP VM launch workflow. Primarily, it introduces the architectural defines, its support in the SEV library and extends the tests to interact with the SEV-SNP ioctl() wrappers. Patch 1 - Do not advertise SNP on initialization failure Patch 2 - SNP test for KVM_SEV_INIT2 Patch 3 - Add vmgexit helper Patch 4 - Add SMT control interface helper Patch 5 - Replace assert() with TEST_ASSERT_EQ() Patch 6 - Introduce SEV+ VM type check Patch 7 - SNP iotcl() plumbing for the SEV library Patch 8 - Force set GUEST_MEMFD for SNP Patch 9 - Cleanups of smoke test - Decouple policy from type Patch 10 - SNP smoke test The series is based on git.kernel.org/pub/scm/virt/kvm/kvm.git next v7..v8: * Dropped exporting the SNP initialized API from ccp to KVM. Instead call SNP_PLATFORM_STATUS within KVM to query the initialization. (Tom) While it may be cheaper to query sev->snp_initialized from ccp, making the SNP platform call within KVM does away with any dependencies. v6..v7: https://lore.kernel.org/kvm/20250221210200.244405-7-prsampat@amd.com/ Based on comments from Sean - * Replaced FW check with sev->snp_initialized * Dropped the patch which removes SEV+ KVM advertisement if INIT fails. This should be now be resolved by the combination of the patches [1,2] from Ashish. * Change vmgexit to an inline function * Export SMT control parsing interface to kvm_util Note: hyperv_cpuid KST only compile tested * Replace assert() with TEST_ASSERT_EQ() within SEV library * Define KVM_SEV_PAGE_TYPE_INVALID for SEV call of encrypt_region() * Parameterize encrypt_region() to include privatize_region() * Deduplication of sev test calls between SEV,SEV-ES and SNP * Removed FW version tests for SNP * Included testing of SNP_POLICY_DBG * Dropped most tags from patches that have been changed or indirectly affected [1] https://lore.kernel.org/all/d6d08c6b-9602-4f3d-92c2-8db6d50a1b92@amd.com [2] https://lore.kernel.org/all/f78ddb64087df27e7bcb1ae0ab53f55aa0804fab.173922… v5..v6: https://lore.kernel.org/kvm/ab433246-e97c-495b-ab67-b0cb1721fb99@amd.com/ * Rename is_sev_platform_init to sev_fw_initialized (Nikunj) * Rename KVM CPU feature X86_FEATURE_SNP to X86_FEATURE_SEV_SNP (Nikunj) * Collected Tags from Nikunj, Pankaj, Srikanth. v4..v5: https://lore.kernel.org/kvm/8e7d8172-879e-4a28-8438-343b1c386ec9@amd.com/ * Introduced a check to disable advertising support for SEV, SEV-ES and SNP when platform initialization fails (Nikunj) * Remove the redundant SNP check within is_sev_vm() (Nikunj) * Cleanup of the encrypt_region flow for better readability (Nikunj) * Refactor paths to use the canonical $(ARCH) to rebase for kvm/next v3..v4: https://lore.kernel.org/kvm/20241114234104.128532-1-pratikrajesh.sampat@amd… * Remove SNP FW API version check in the test and ensure the KVM capability advertises the presence of the feature. Retain the minimum version definitions to exercise these API versions in the smoke test * Retained only the SNP smoke test and SNP_INIT2 test * The SNP architectural defined merged with SNP_INIT2 test patch * SNP shutdown merged with SNP smoke test patch * Add SEV VM type check to abstract comparisons and reduce clutter * Define a SNP default policy which sets bits based on the presence of SMT * Decouple privatization and encryption for it to be SNP agnostic * Assert for only positive tests using vm_ioctl() * Dropped tested-by tags In summary - based on comments from Sean, I have primarily reduced the scope of this patch series to focus on breaking down the SNP smoke test patch (v3 - patch2) to first introduce SEV-SNP support and use this interface to extend the sev_init2 and the sev_smoke test. The rest of the v3 patchset that introduces ioctl, pre fault, fallocate and negative tests, will be re-worked and re-introduced subsequently in future patch series post addressing the issues discussed. v2..v3: https://lore.kernel.org/kvm/20240905124107.6954-1-pratikrajesh.sampat@amd.c… * Remove the assignments for the prefault and fallocate test type enums. * Fix error message for sev launch measure and finish. * Collect tested-by tags [Peter, Srikanth] Pratik R. Sampat (10): KVM: SEV: Disable SEV-SNP support on initialization failure KVM: selftests: SEV-SNP test for KVM_SEV_INIT2 KVM: selftests: Add vmgexit helper KVM: selftests: Add SMT control state helper KVM: selftests: Replace assert() with TEST_ASSERT_EQ() KVM: selftests: Introduce SEV VM type check KVM: selftests: Add library support for interacting with SNP KVM: selftests: Force GUEST_MEMFD flag for SNP VM type KVM: selftests: Abstractions for SEV to decouple policy from type KVM: selftests: Add a basic SEV-SNP smoke test arch/x86/include/uapi/asm/kvm.h | 1 + arch/x86/kvm/svm/sev.c | 30 +++++- tools/arch/x86/include/uapi/asm/kvm.h | 1 + .../testing/selftests/kvm/include/kvm_util.h | 35 +++++++ .../selftests/kvm/include/x86/processor.h | 1 + tools/testing/selftests/kvm/include/x86/sev.h | 42 ++++++++- tools/testing/selftests/kvm/lib/kvm_util.c | 7 +- .../testing/selftests/kvm/lib/x86/processor.c | 4 +- tools/testing/selftests/kvm/lib/x86/sev.c | 93 +++++++++++++++++-- .../testing/selftests/kvm/x86/hyperv_cpuid.c | 19 ---- .../selftests/kvm/x86/sev_init2_tests.c | 13 +++ .../selftests/kvm/x86/sev_smoke_test.c | 75 +++++++++------ 12 files changed, 261 insertions(+), 60 deletions(-) -- 2.43.0

2 weeks, 5 days

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[PATCH v2] selftests: riscv: fix v_exec_initval_nolibc.c

by Ignacio Encinas

Vector registers are zero initialized by the kernel. Stop accepting "all ones" as a clean value. Note that this was not working as expected given that value == 0xff can be assumed to be always false by the compiler as value's range is [-128, 127]. Both GCC (-Wtype-limits) and clang (-Wtautological-constant-out-of-range-compare) warn about this. Reviewed-by: Charlie Jenkins <charlie(a)rivosinc.com> Tested-by: Charlie Jenkins <charlie(a)rivosinc.com> Signed-off-by: Ignacio Encinas <ignacio(a)iencinas.com> --- Changes in v2: Remove code that becomes useless now that the only "clean" value for vector registers is 0. - Link to v1: https://lore.kernel.org/r/20250305-fix-v_exec_initval_nolibc-v1-1-b87b60e43… --- tools/testing/selftests/riscv/vector/v_exec_initval_nolibc.c | 10 +++------- 1 file changed, 3 insertions(+), 7 deletions(-) diff --git a/tools/testing/selftests/riscv/vector/v_exec_initval_nolibc.c b/tools/testing/selftests/riscv/vector/v_exec_initval_nolibc.c index 35c0812e32de0c82a54f84bd52c4272507121e35..4dde05e45a04122b566cedc36d20b072413b00e2 100644 --- a/tools/testing/selftests/riscv/vector/v_exec_initval_nolibc.c +++ b/tools/testing/selftests/riscv/vector/v_exec_initval_nolibc.c @@ -6,7 +6,7 @@ * the values. To further ensure consistency, this file is compiled without * libc and without auto-vectorization. * - * To be "clean" all values must be either all ones or all zeroes. + * To be "clean" all values must be all zeroes. */ #define __stringify_1(x...) #x @@ -14,9 +14,8 @@ int main(int argc, char **argv) { - char prev_value = 0, value; + char value = 0; unsigned long vl; - int first = 1; if (argc > 2 && strcmp(argv[2], "x")) asm volatile ( @@ -44,14 +43,11 @@ int main(int argc, char **argv) "vsrl.vi " __stringify(register) ", " __stringify(register) ", 8\n\t" \ ".option pop\n\t" \ : "=r" (value)); \ - if (first) { \ - first = 0; \ - } else if (value != prev_value || !(value == 0x00 || value == 0xff)) { \ + if (value != 0x00) { \ printf("Register " __stringify(register) \ " values not clean! value: %u\n", value); \ exit(-1); \ } \ - prev_value = value; \ } \ }) --- base-commit: 03d38806a902b36bf364cae8de6f1183c0a35a67 change-id: 20250301-fix-v_exec_initval_nolibc-498d976c372d Best regards, -- Ignacio Encinas <ignacio(a)iencinas.com>

2 weeks, 5 days

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[PATCH 00/10] cgroup/cpuset: Miscellaneous partition bug fixes and enhancements

by Waiman Long

This patch series fixes a number of bugs in the cpuset partition code as well as improvement in remote partition handling. The test_cpuset_prs.sh is also enhanced to allow more vigorous remote partition testing. Waiman Long (10): cgroup/cpuset: Fix race between newly created partition and dying one cgroup/cpuset: Fix incorrect isolated_cpus update in update_parent_effective_cpumask() cgroup/cpuset: Fix error handling in remote_partition_disable() cgroup/cpuset: Remove remote_partition_check() & make update_cpumasks_hier() handle remote partition cgroup/cpuset: Don't allow creation of local partition over a remote one cgroup/cpuset: Code cleanup and comment update cgroup/cpuset: Remove unneeded goto in sched_partition_write() and rename it selftest/cgroup: Update test_cpuset_prs.sh to use | as effective CPUs and state separator selftest/cgroup: Clean up and restructure test_cpuset_prs.sh selftest/cgroup: Add a remote partition transition test to test_cpuset_prs.sh include/linux/cgroup-defs.h | 1 + include/linux/cgroup.h | 2 +- kernel/cgroup/cgroup.c | 6 + kernel/cgroup/cpuset-internal.h | 1 + kernel/cgroup/cpuset.c | 401 +++++++----- .../selftests/cgroup/test_cpuset_prs.sh | 617 ++++++++++++------ 6 files changed, 649 insertions(+), 379 deletions(-) -- 2.48.1

2 weeks, 5 days

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

by Blaise Boscaccy

This patch series introduces the Hornet LSM. Hornet takes a simple approach to light-skeleton-based eBPF signature verification. Signature data can be easily generated for the binary data that is generated via bpftool gen -L. This signature can be appended to a skeleton executable via scripts/sign-ebpf. Hornet checks the signature against a binary buffer containing the lskel instructions that the loader maps use. 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. Blaise Boscaccy (4): security: Hornet LSM hornet: Introduce sign-ebpf hornet: Add an example lskel data extactor script selftests/hornet: Add a selftest for the hornet LSM Documentation/admin-guide/LSM/Hornet.rst | 51 +++ 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 | 420 +++++++++++++++++++ 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 ++ 18 files changed, 882 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

2 weeks, 5 days

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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

2 weeks, 5 days

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[PATCH net-next v24 00/23] Introducing OpenVPN Data Channel Offload

by Antonio Quartulli

Notable changes since v23: * dropped call to netif_tx_start/stop_all_queues() * dropped NETIF_F_HW_CSUM and NETIF_F_RXCSUM dev flags * dropped conditional call to skb_checksum_help() due to the point above * added call to dst_cache_reset() in nl_peer_modify() * dropped obsolete comment in ovpn_peer_keepalive_work() * reversed scheduling delay computation in ovpn_peer_keepalive_work() Please note that some patches were already reviewed/tested by a few people. These patches have retained the tags as they have hardly been touched. The latest code can also be found at: https://github.com/OpenVPN/ovpn-net-next Thanks a lot! Best Regards, Antonio Quartulli OpenVPN Inc. --- Antonio Quartulli (23): net: introduce OpenVPN Data Channel Offload (ovpn) ovpn: add basic netlink support ovpn: add basic interface creation/destruction/management routines ovpn: keep carrier always on for MP interfaces ovpn: introduce the ovpn_peer object ovpn: introduce the ovpn_socket object ovpn: implement basic TX path (UDP) ovpn: implement basic RX path (UDP) ovpn: implement packet processing ovpn: store tunnel and transport statistics ovpn: implement TCP transport skb: implement skb_send_sock_locked_with_flags() ovpn: add support for MSG_NOSIGNAL in tcp_sendmsg ovpn: implement multi-peer support ovpn: implement peer lookup logic ovpn: implement keepalive mechanism ovpn: add support for updating local or remote UDP endpoint ovpn: implement peer add/get/dump/delete via netlink ovpn: implement key add/get/del/swap via netlink ovpn: kill key and notify userspace in case of IV exhaustion ovpn: notify userspace when a peer is deleted ovpn: add basic ethtool support testing/selftests: add test tool and scripts for ovpn module Documentation/netlink/specs/ovpn.yaml | 367 +++ Documentation/netlink/specs/rt_link.yaml | 16 + MAINTAINERS | 11 + drivers/net/Kconfig | 15 + drivers/net/Makefile | 1 + drivers/net/ovpn/Makefile | 22 + drivers/net/ovpn/bind.c | 55 + drivers/net/ovpn/bind.h | 101 + drivers/net/ovpn/crypto.c | 211 ++ drivers/net/ovpn/crypto.h | 145 ++ drivers/net/ovpn/crypto_aead.c | 409 ++++ drivers/net/ovpn/crypto_aead.h | 29 + drivers/net/ovpn/io.c | 455 ++++ drivers/net/ovpn/io.h | 34 + drivers/net/ovpn/main.c | 330 +++ drivers/net/ovpn/main.h | 14 + drivers/net/ovpn/netlink-gen.c | 213 ++ drivers/net/ovpn/netlink-gen.h | 41 + drivers/net/ovpn/netlink.c | 1250 ++++++++++ drivers/net/ovpn/netlink.h | 18 + drivers/net/ovpn/ovpnpriv.h | 57 + drivers/net/ovpn/peer.c | 1364 +++++++++++ drivers/net/ovpn/peer.h | 163 ++ drivers/net/ovpn/pktid.c | 129 ++ drivers/net/ovpn/pktid.h | 87 + drivers/net/ovpn/proto.h | 118 + drivers/net/ovpn/skb.h | 61 + drivers/net/ovpn/socket.c | 244 ++ drivers/net/ovpn/socket.h | 49 + drivers/net/ovpn/stats.c | 21 + drivers/net/ovpn/stats.h | 47 + drivers/net/ovpn/tcp.c | 592 +++++ drivers/net/ovpn/tcp.h | 36 + drivers/net/ovpn/udp.c | 442 ++++ drivers/net/ovpn/udp.h | 25 + include/linux/skbuff.h | 2 + include/uapi/linux/if_link.h | 15 + include/uapi/linux/ovpn.h | 109 + include/uapi/linux/udp.h | 1 + net/core/skbuff.c | 18 +- net/ipv6/af_inet6.c | 1 + net/ipv6/udp.c | 1 + tools/testing/selftests/Makefile | 1 + tools/testing/selftests/net/ovpn/.gitignore | 2 + tools/testing/selftests/net/ovpn/Makefile | 31 + tools/testing/selftests/net/ovpn/common.sh | 92 + tools/testing/selftests/net/ovpn/config | 10 + tools/testing/selftests/net/ovpn/data64.key | 5 + tools/testing/selftests/net/ovpn/ovpn-cli.c | 2395 ++++++++++++++++++++ tools/testing/selftests/net/ovpn/tcp_peers.txt | 5 + .../testing/selftests/net/ovpn/test-chachapoly.sh | 9 + .../selftests/net/ovpn/test-close-socket-tcp.sh | 9 + .../selftests/net/ovpn/test-close-socket.sh | 45 + tools/testing/selftests/net/ovpn/test-float.sh | 9 + tools/testing/selftests/net/ovpn/test-tcp.sh | 9 + tools/testing/selftests/net/ovpn/test.sh | 113 + tools/testing/selftests/net/ovpn/udp_peers.txt | 5 + 57 files changed, 10054 insertions(+), 5 deletions(-) --- base-commit: 702e3fa16cd42ba712825e8d6171ea4755bc0491 change-id: 20241002-b4-ovpn-eeee35c694a2 Best regards, -- Antonio Quartulli <antonio(a)openvpn.net>

2 weeks, 6 days

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Linux-kselftest-mirror March 2025