April 2025 - Linux-kselftest-mirror

Call for Participation: Automated Testing Summit 2025 @ OSS NA

by Gustavo Padovan

The Automated Testing Summit (ATS) 2025 will be held as a co-located event at the Open Source Summit North America, and we’re now accepting talk proposals! https://events.linuxfoundation.org/open-source-summit-north-america/feature… 📅 Date: June 26, 2025 📍 Location: Denver, CO, USA Hosted by KernelCI, ATS is a technical summit focused on the challenges of testing and quality assurance in the Linux ecosystem — especially in upstream kernel development, embedded systems, cloud environments, and CI integration. This is a great opportunity to share your work on: * Kernel and userspace test frameworks * Lab infrastructure and automation * CI/CD pipelines for Linux * Fuzzing, performance testing, and debugging tools * Sharing and standardizing test results across systems Whether you’re working on kernel testing, running tests on hardware labs, developing QA tools, or building infrastructure that scales across projects, ATS is the place to collaborate and move the ecosystem forward. Submit your talk by May 18, 2025: 👉 Call for Proposals (CFP): https://sessionize.com/atsna2025 We hope to see you in Denver! — The KernelCI Team

1 day, 3 hours

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[PATCH v3 00/32] kselftest harness and nolibc compatibility

by Thomas Weißschuh

Nolibc is useful for selftests as the test programs can be very small, and compiled with just a kernel crosscompiler, without userspace support. Currently nolibc is only usable with kselftest.h, not the more convenient to use kselftest_harness.h This series provides this compatibility by adding new features to nolibc and removing the usage of problematic features from the harness. The first half of the series are changes to the harness, the second one are for nolibc. Both parts are very independent and should go through different trees. The last patch is not meant to be applied and serves as test that everything works together correctly. Signed-off-by: Thomas Weißschuh <thomas.weissschuh(a)linutronix.de> --- Changes in v3: - Send patches to correct kselftest harness maintainers - Move harness selftest to dedicated directory - Add harness selftest to MAINTAINERS - Integrate harness selftest cleanup with the selftest framework - Consistently use "kselftest harness" in commit messages - Properly propagate kselftest harness failure - Link to v2: https://lore.kernel.org/r/20250407-nolibc-kselftest-harness-v2-0-f8812f76e9… Changes in v2: - Rebase unto v6.15-rc1 - Rename internal nolibc symbols - Handle edge case of waitpid(INT_MIN) == ESRCH - Fix arm configurations for final testing patch - Clean up global getopt.h variable declarations - Add Acks from Willy - Link to v1: https://lore.kernel.org/r/20250304-nolibc-kselftest-harness-v1-0-adca7cd231… --- Thomas Weißschuh (32): selftests: harness: Add kselftest harness selftest selftests: harness: Use C89 comment style selftests: harness: Ignore unused variant argument warning selftests: harness: Mark functions without prototypes static selftests: harness: Remove inline qualifier for wrappers selftests: harness: Remove dependency on libatomic selftests: harness: Implement test timeouts through pidfd selftests: harness: Don't set setup_completed for fixtureless tests selftests: harness: Always provide "self" and "variant" selftests: harness: Move teardown conditional into test metadata selftests: harness: Add teardown callback to test metadata selftests: harness: Stop using setjmp()/longjmp() selftests: harness: Guard includes on nolibc tools/nolibc: handle intmax_t/uintmax_t in printf tools/nolibc: use intmax definitions from compiler tools/nolibc: use pselect6_time64 if available tools/nolibc: use ppoll_time64 if available tools/nolibc: add tolower() and toupper() tools/nolibc: add _exit() tools/nolibc: add setpgrp() tools/nolibc: implement waitpid() in terms of waitid() Revert "selftests/nolibc: use waitid() over waitpid()" tools/nolibc: add dprintf() and vdprintf() tools/nolibc: add getopt() tools/nolibc: allow different write callbacks in printf tools/nolibc: allow limiting of printf destination size tools/nolibc: add snprintf() and friends selftests/nolibc: use snprintf() for printf tests selftests/nolibc: rename vfprintf test suite selftests/nolibc: add test for snprintf() truncation tools/nolibc: implement width padding in printf() HACK: selftests/nolibc: demonstrate usage of the kselftest harness MAINTAINERS | 1 + tools/include/nolibc/Makefile | 1 + tools/include/nolibc/getopt.h | 101 ++ tools/include/nolibc/nolibc.h | 1 + tools/include/nolibc/stdint.h | 4 +- tools/include/nolibc/stdio.h | 127 +- tools/include/nolibc/string.h | 17 + tools/include/nolibc/sys.h | 105 +- tools/testing/selftests/Makefile | 1 + tools/testing/selftests/kselftest_harness.h | 181 +- .../testing/selftests/kselftest_harness/.gitignore | 2 + tools/testing/selftests/kselftest_harness/Makefile | 7 + .../selftests/kselftest_harness/harness-selftest.c | 129 ++ .../kselftest_harness/harness-selftest.expected | 62 + .../kselftest_harness/harness-selftest.sh | 13 + tools/testing/selftests/nolibc/Makefile | 13 +- tools/testing/selftests/nolibc/harness-selftest.c | 1 + tools/testing/selftests/nolibc/nolibc-test.c | 1729 +------------------- tools/testing/selftests/nolibc/run-tests.sh | 2 +- 19 files changed, 637 insertions(+), 1860 deletions(-) --- base-commit: 0af2f6be1b4281385b618cb86ad946eded089ac8 change-id: 20250130-nolibc-kselftest-harness-8b2c8cac43bf Best regards, -- Thomas Weißschuh <thomas.weissschuh(a)linutronix.de>

1 day, 4 hours

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[PATCH v3 0/8] perform /proc/pid/maps read and PROCMAP_QUERY under RCU

by Suren Baghdasaryan

After a long delay I'm posting next iteration of lockless /proc/pid/maps reading patchset. Differences from v2 [1]: - Add a set of tests concurrently modifying address space and checking for correct reading results; - Use new mmap_lock_speculate_xxx APIs for concurrent change detection and retries; - Add lockless PROCMAP_QUERY execution support; The new tests are designed to check for any unexpected data tearing while performing some common address space modifications (vma split, resize and remap). Even before these changes, reading /proc/pid/maps might have inconsistent data because the file is read page-by-page with mmap_lock being dropped between the pages. Such tearing is expected and userspace is supposed to deal with that possibility. An example of user-visible inconsistency can be that the same vma is printed twice: once before it was modified and then after the modifications. For example if vma was extended, it might be found and reported twice. Whan is not expected is to see a gap where there should have been a vma both before and after modification. This patchset increases the chances of such tearing, therefore it's event more important now to test for unexpected inconsistencies. Thanks to Paul McKenney who developed a benchmark to test performance of concurrent reads and updates, we also have data on performance benefits: The test has a pair of processes scanning /proc/PID/maps, and another process unmapping and remapping 4K pages from a 128MB range of anonymous memory. At the end of each 10-second run, the latency of each mmap() or munmap() operation is measured, and for each run the maximum and mean latency is printed. (Yes, the map/unmap process is started first, its PID is passed to the scanners, and then the map/unmap process waits until both scanners are running before starting its timed test. The scanners keep scanning until the specified /proc/PID/maps file disappears.) In summary, with stock mm, 78% of the runs had maximum latencies in excess of 0.5 milliseconds, and with more then half of the runs' latencies exceeding a full millisecond. In contrast, 98% of the runs with Suren's patch series applied had maximum latencies of less than 0.5 milliseconds. From a median-performance viewpoint, Suren's series also looks good, with stock mm weighing in at 13 microseconds and Suren's series at 10 microseconds, better than a 20% improvement. [1] https://lore.kernel.org/all/20240123231014.3801041-1-surenb@google.com/ Suren Baghdasaryan (8): selftests/proc: add /proc/pid/maps tearing from vma split test selftests/proc: extend /proc/pid/maps tearing test to include vma resizing selftests/proc: extend /proc/pid/maps tearing test to include vma remapping selftests/proc: test PROCMAP_QUERY ioctl while vma is concurrently modified selftests/proc: add verbose more for tests to facilitate debugging mm: make vm_area_struct anon_name field RCU-safe mm/maps: read proc/pid/maps under RCU mm/maps: execute PROCMAP_QUERY ioctl under RCU fs/proc/internal.h | 6 + fs/proc/task_mmu.c | 233 +++++- include/linux/mm_inline.h | 28 +- include/linux/mm_types.h | 3 +- mm/madvise.c | 30 +- tools/testing/selftests/proc/proc-pid-vm.c | 793 ++++++++++++++++++++- 6 files changed, 1061 insertions(+), 32 deletions(-) base-commit: 79f35c4125a9a3fd98efeed4cce1cd7ce5311a44 -- 2.49.0.805.g082f7c87e0-goog

1 day, 7 hours

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[PATCH v13 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/ To: Thomas Gleixner <tglx(a)linutronix.de> To: Ingo Molnar <mingo(a)redhat.com> To: Borislav Petkov <bp(a)alien8.de> To: Dave Hansen <dave.hansen(a)linux.intel.com> To: x86(a)kernel.org To: H. Peter Anvin <hpa(a)zytor.com> To: Andrew Morton <akpm(a)linux-foundation.org> To: Liam R. Howlett <Liam.Howlett(a)oracle.com> To: Vlastimil Babka <vbabka(a)suse.cz> To: Lorenzo Stoakes <lorenzo.stoakes(a)oracle.com> To: Paul Walmsley <paul.walmsley(a)sifive.com> To: Palmer Dabbelt <palmer(a)dabbelt.com> To: Albert Ou <aou(a)eecs.berkeley.edu> To: Conor Dooley <conor(a)kernel.org> To: Rob Herring <robh(a)kernel.org> To: Krzysztof Kozlowski <krzk+dt(a)kernel.org> To: Arnd Bergmann <arnd(a)arndb.de> To: Christian Brauner <brauner(a)kernel.org> To: Peter Zijlstra <peterz(a)infradead.org> To: Oleg Nesterov <oleg(a)redhat.com> To: Eric Biederman <ebiederm(a)xmission.com> To: Kees Cook <kees(a)kernel.org> To: Jonathan Corbet <corbet(a)lwn.net> To: Shuah Khan <shuah(a)kernel.org> To: Jann Horn <jannh(a)google.com> To: Conor Dooley <conor+dt(a)kernel.org> To: Miguel Ojeda <ojeda(a)kernel.org> To: Alex Gaynor <alex.gaynor(a)gmail.com> To: Boqun Feng <boqun.feng(a)gmail.com> To: Gary Guo <gary(a)garyguo.net> To: Björn Roy Baron <bjorn3_gh(a)protonmail.com> To: Benno Lossin <benno.lossin(a)proton.me> To: Andreas Hindborg <a.hindborg(a)kernel.org> To: Alice Ryhl <aliceryhl(a)google.com> To: Trevor Gross <tmgross(a)umich.edu> Cc: linux-kernel(a)vger.kernel.org Cc: linux-fsdevel(a)vger.kernel.org Cc: linux-mm(a)kvack.org Cc: linux-riscv(a)lists.infradead.org Cc: devicetree(a)vger.kernel.org Cc: linux-arch(a)vger.kernel.org Cc: linux-doc(a)vger.kernel.org Cc: linux-kselftest(a)vger.kernel.org Cc: alistair.francis(a)wdc.com Cc: richard.henderson(a)linaro.org Cc: jim.shu(a)sifive.com Cc: andybnac(a)gmail.com Cc: kito.cheng(a)sifive.com Cc: charlie(a)rivosinc.com Cc: atishp(a)rivosinc.com Cc: evan(a)rivosinc.com Cc: cleger(a)rivosinc.com Cc: alexghiti(a)rivosinc.com Cc: samitolvanen(a)google.com Cc: broonie(a)kernel.org Cc: rick.p.edgecombe(a)intel.com Cc: rust-for-linux(a)vger.kernel.org changelog --------- v13: - cpu_supports_shadow_stack/cpu_supports_indirect_br_lp_instr uses riscv_has_extension_unlikely() - uses nops(count) to create nop slide - RISCV_ACQUIRE_BARRIER is not needed in `amo_user_shstk`. Removed it - changed ternaries to simply use implicit casting to convert to bool. - kernel command line allows to disable zicfilp and zicfiss independently. updated kernel-parameters.txt. - ptrace user abi for cfi uses bitmasks instead of bitfields. Added ptrace kselftest. - cosmetic and grammatical changes to documentation. 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 v13: - changelog posted just below cover letter - Link to v12: https://lore.kernel.org/r/20250314-v5_user_cfi_series-v12-0-e51202b53138@ri… Changes in v12: - changelog posted just below cover letter - Link to v11: https://lore.kernel.org/r/20250310-v5_user_cfi_series-v11-0-86b36cbfb910@ri… Changes in v11: - changelog posted just below cover letter - 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: kernel command line option to opt out of user cfi riscv: enable kernel access to shadow stack memory via FWFT sbi call 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/admin-guide/kernel-parameters.txt | 8 + Documentation/arch/riscv/index.rst | 2 + Documentation/arch/riscv/zicfilp.rst | 115 +++++ Documentation/arch/riscv/zicfiss.rst | 179 +++++++ .../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 | 12 + 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 | 96 ++++ arch/riscv/include/asm/vector.h | 3 + arch/riscv/include/uapi/asm/hwprobe.h | 2 + arch/riscv/include/uapi/asm/ptrace.h | 34 ++ 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 | 28 +- arch/riscv/kernel/head.S | 23 + arch/riscv/kernel/process.c | 26 +- arch/riscv/kernel/ptrace.c | 95 ++++ 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 | 545 +++++++++++++++++++++ arch/riscv/kernel/vdso/Makefile | 6 + 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 | 171 +++++++ tools/testing/selftests/riscv/cfi/shadowstack.c | 385 +++++++++++++++ tools/testing/selftests/riscv/cfi/shadowstack.h | 27 + 55 files changed, 2346 insertions(+), 29 deletions(-) --- base-commit: 39a803b754d5224a3522016b564113ee1e4091b2 change-id: 20240930-v5_user_cfi_series-3dc332f8f5b2 -- - debug

1 day, 8 hours

2
31
0 0

[PATCH v1 00/16] iommufd: Add vIOMMU infrastructure (Part-4 vCMDQ)

by Nicolin Chen

The vIOMMU object is designed to represent a slice of an IOMMU HW for its virtualization features shared with or passed to user space (a VM mostly) in a way of HW acceleration. This extended the HWPT-based design for more advanced virtualization feature. A vCMDQ introduced by this series as a part of the vIOMMU infrastructure represents a HW supported queue/buffer for VM to use exclusively, e.g. - NVIDIA's virtual command queue - AMD vIOMMU's command buffer either of which is an IOMMU HW feature to directly load and execute cache invalidation commands issued by a guest kernel, to shoot down TLB entries that HW cached for guest-owned stage-1 page table entries. This is a big improvement since there is no VM Exit during an invalidation, compared to the traditional invalidation pathway by trapping a guest-own invalidation queue and forwarding those commands/requests to the host kernel that will eventually fill a HW-owned queue to execute those commands. Thus, a vCMDQ object, as an initial use case, is all about a guest-owned HW command queue that VMM can allocate/configure depending on the request from a guest kernel. Introduce a new IOMMUFD_OBJ_VCMDQ and its allocator IOMMUFD_CMD_VCMDQ_ALLOC allowing VMM to forward the IOMMU-specific queue info, such as queue base address, size, and etc. Meanwhile, a guest-owned command queue needs the kernel (a command queue driver) to control the queue by reading/writing its consumer and producer indexes, which means the command queue HW allows the guest kernel to get a direct R/W access to those registers. Introduce an mmap infrastructure to the iommufd core so as to support pass through a piece of MMIO region from the host physical address space to the guest physical address space. The VMA info (vm_pgoff/size) used by an mmap must be pre-allocated during the IOMMUFD_CMD_VCMDQ_ALLOC and given those info to the user space as an output driver-data by the IOMMUFD_CMD_VCMDQ_ALLOC. So, this requires a driver-specific user data support by a vIOMMU object. As a real-world use case, this series implements a vCMDQ support to the tegra241-cmdqv driver for the vCMDQ on NVIDIA Grace CPU. In another word, this is also the Tegra CMDQV series Part-2 (user-space support), reworked from Previous RFCv1: https://lore.kernel.org/all/cover.1712978212.git.nicolinc@nvidia.com/ This is on Github: https://github.com/nicolinc/iommufd/commits/iommufd_vcmdq-v1 Paring QEMU branch for testing: https://github.com/nicolinc/qemu/commits/wip/for_iommufd_vcmdq-v1 Thanks Nicolin Nicolin Chen (16): iommu: Pass in a driver-level user data structure to viommu_alloc op iommufd/viommu: Allow driver-specific user data for a vIOMMU object iommu: Add iommu_copy_struct_to_user helper iommufd: Add iommufd_struct_destroy to revert iommufd_viommu_alloc iommufd/selftest: Support user_data in mock_viommu_alloc iommufd/selftest: Add covearge for viommu data iommufd/viommu: Add driver-allocated vDEVICE support iommufd/viommu: Introduce IOMMUFD_OBJ_VCMDQ and its related struct iommufd/viommmu: Add IOMMUFD_CMD_VCMDQ_ALLOC ioctl iommufd: Add mmap interface iommufd/selftest: Add coverage for the new mmap interface Documentation: userspace-api: iommufd: Update vCMDQ iommu/tegra241-cmdqv: Use request_threaded_irq iommu/arm-smmu-v3: Add vsmmu_alloc impl op iommu/tegra241-cmdqv: Add user-space use support iommu/tegra241-cmdqv: Add IOMMU_VEVENTQ_TYPE_TEGRA241_CMDQV support drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h | 24 +- drivers/iommu/iommufd/iommufd_private.h | 20 +- drivers/iommu/iommufd/iommufd_test.h | 17 + include/linux/iommu.h | 43 ++- include/linux/iommufd.h | 93 +++++ include/uapi/linux/iommufd.h | 87 +++++ tools/testing/selftests/iommu/iommufd_utils.h | 21 +- .../arm/arm-smmu-v3/arm-smmu-v3-iommufd.c | 26 +- .../iommu/arm/arm-smmu-v3/tegra241-cmdqv.c | 349 +++++++++++++++++- drivers/iommu/iommufd/driver.c | 54 +++ drivers/iommu/iommufd/main.c | 54 ++- drivers/iommu/iommufd/selftest.c | 58 ++- drivers/iommu/iommufd/viommu.c | 78 +++- tools/testing/selftests/iommu/iommufd.c | 34 +- .../selftests/iommu/iommufd_fail_nth.c | 5 +- Documentation/userspace-api/iommufd.rst | 11 + 16 files changed, 912 insertions(+), 62 deletions(-) -- 2.43.0

1 day, 9 hours

6
51
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[PATCH v5 00/13] 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] --- 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 (13): riscv: sbi: add Firmware Feature (FWFT) SBI extensions definitions 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 | 75 ++++++ 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, 610 insertions(+), 15 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

1 day, 12 hours

2
23
0 0

[PATCH 0/3] tools/nolibc: make all headers usable directly

by Thomas Weißschuh

Make sure that any nolibc header can be included in any order. Even if nolibc.h was not pre-included already. This conflicts indirectly with "tools/nolibc: various new functions" [0]. I'll resolve those conflicts when applying. [0] https://lore.kernel.org/lkml/20250423-nolibc-misc-v1-0-a925bf40297b@linutro… Signed-off-by: Thomas Weißschuh <thomas.weissschuh(a)linutronix.de> --- Thomas Weißschuh (3): tools/nolibc: add target to check header usability tools/nolibc: include nolibc.h early from all header files selftests/nolibc: always run nolibc header check tools/include/nolibc/Makefile | 9 +++++++++ tools/include/nolibc/ctype.h | 6 +++--- tools/include/nolibc/dirent.h | 6 +++--- tools/include/nolibc/elf.h | 6 +++--- tools/include/nolibc/errno.h | 6 +++--- tools/include/nolibc/fcntl.h | 6 +++--- tools/include/nolibc/getopt.h | 6 +++--- tools/include/nolibc/signal.h | 6 +++--- tools/include/nolibc/stdio.h | 6 +++--- tools/include/nolibc/stdlib.h | 6 +++--- tools/include/nolibc/string.h | 7 +++---- tools/include/nolibc/sys.h | 6 +++--- tools/include/nolibc/sys/auxv.h | 6 +++--- tools/include/nolibc/sys/mman.h | 6 +++--- tools/include/nolibc/sys/stat.h | 7 +++---- tools/include/nolibc/sys/syscall.h | 6 +++--- tools/include/nolibc/sys/time.h | 6 +++--- tools/include/nolibc/sys/wait.h | 7 +++---- tools/include/nolibc/time.h | 6 +++--- tools/include/nolibc/types.h | 6 +++--- tools/include/nolibc/unistd.h | 6 +++--- tools/testing/selftests/nolibc/Makefile | 2 +- 22 files changed, 70 insertions(+), 64 deletions(-) --- base-commit: e90ce42e81381665dbcedc5fa12e74759ee89639 change-id: 20250423-nolibc-header-check-8c9d21850d3f Best regards, -- Thomas Weißschuh <thomas.weissschuh(a)linutronix.de>

1 day, 12 hours

2
4
0 0

[PATCH 0/2] selftests: ublk: misc fixes

by Uday Shankar

Fix a couple of small issues in the ublk selftests Signed-off-by: Uday Shankar <ushankar(a)purestorage.com> --- Uday Shankar (2): selftests: ublk: kublk: build with -Werror selftests: ublk: common: fix _get_disk_dev_t for pre-9.0 coreutils tools/testing/selftests/ublk/Makefile | 2 +- tools/testing/selftests/ublk/test_common.sh | 4 ++-- 2 files changed, 3 insertions(+), 3 deletions(-) --- base-commit: d2ce053979d1d302fb009f6e1538a0776f177e1a change-id: 20250423-ublk_selftests-3b2e200b1fa4 Best regards, -- Uday Shankar <ushankar(a)purestorage.com>

1 day, 12 hours

3
6
0 0

[PATCH net-next v10 0/9] Device memory TCP TX

by Mina Almasry

v10: https://lore.kernel.org/netdev/20250417231540.2780723-1-almasrymina@google.… Addressed comments following conversations with Pavel, Stan, and Harshitha. Thank you guys for the reviews again. Overall minor changes: Changelog: - Check for !niov->pp in io_zcrx_recv_frag, just in case we end up with a TX niov in that path (Pavel). - Fix locking case in !netif_device_present (Jakub/Stan). v9: https://lore.kernel.org/netdev/20250415224756.152002-1-almasrymina@google.c… Changelog: - Use priv->bindings list instead of sock_bindings_list. This was missed during the rebase as the bindings have been updated to use priv->bindings recently (thanks Stan!) v8: https://lore.kernel.org/netdev/20250308214045.1160445-1-almasrymina@google.… Only address minor comments on V7 Changelog: - Use netdev locking instead of rtnl_locking to match rx path. - Now that iouring zcrx is in net-next, use NET_IOV_IOURING instead of NET_IOV_UNSPECIFIED. - Post send binding to net_devmem_dmabuf_bindings after it's been fully initialized (Stan). v7: https://lore.kernel.org/netdev/20250227041209.2031104-1-almasrymina@google.… === Changelog: - Check the dmabuf net_iov binding belongs to the device the TX is going out on. (Jakub) - Provide detailed inspection of callsites of __skb_frag_ref/skb_page_unref in patch 2's changelog (Jakub) v6: https://lore.kernel.org/netdev/20250222191517.743530-1-almasrymina@google.c… === v6 has no major changes. Addressed a few issues from Paolo and David, and collected Acks from Stan. Thank you everyone for the review! Changes: - retain behavior to process MSG_FASTOPEN even if the provided cmsg is invalid (Paolo). - Rework the freeing of tx_vec slightly (it now has its own err label). (Paolo). - Squash the commit that makes dmabuf unbinding scheduled work into the same one which implements the TX path so we don't run into future errors on bisecting (Paolo). - Fix/add comments to explain how dmabuf binding refcounting works (David). v5: https://lore.kernel.org/netdev/20250220020914.895431-1-almasrymina@google.c… === v5 has no major changes; it clears up the relatively minor issues pointed out to in v4, and rebases the series on top of net-next to resolve the conflict with a patch that raced to the tree. It also collects the review tags from v4. Changes: - Rebase to net-next - Fix issues in selftest (Stan). - Address comments in the devmem and netmem driver docs (Stan and Bagas) - Fix zerocopy_fill_skb_from_devmem return error code (Stan). v4: https://lore.kernel.org/netdev/20250203223916.1064540-1-almasrymina@google.… === v4 mainly addresses the critical driver support issue surfaced in v3 by Paolo and Stan. Drivers aiming to support netmem_tx should make sure not to pass the netmem dma-addrs to the dma-mapping APIs, as these dma-addrs may come from dma-bufs. Additionally other feedback from v3 is addressed. Major changes: - Add helpers to handle netmem dma-addrs. Add GVE support for netmem_tx. - Fix binding->tx_vec not being freed on error paths during the tx binding. - Add a minimal devmem_tx test to devmem.py. - Clean up everything obsolete from the cover letter (Paolo). v3: https://patchwork.kernel.org/project/netdevbpf/list/?series=929401&state=* === Address minor comments from RFCv2 and fix a few build warnings and ynl-regen issues. No major changes. RFC v2: https://patchwork.kernel.org/project/netdevbpf/list/?series=920056&state=* ======= RFC v2 addresses much of the feedback from RFC v1. I plan on sending something close to this as net-next reopens, sending it slightly early to get feedback if any. Major changes: -------------- - much improved UAPI as suggested by Stan. We now interpret the iov_base of the passed in iov from userspace as the offset into the dmabuf to send from. This removes the need to set iov.iov_base = NULL which may be confusing to users, and enables us to send multiple iovs in the same sendmsg() call. ncdevmem and the docs show a sample use of that. - Removed the duplicate dmabuf iov_iter in binding->iov_iter. I think this is good improvment as it was confusing to keep track of 2 iterators for the same sendmsg, and mistracking both iterators caused a couple of bugs reported in the last iteration that are now resolved with this streamlining. - Improved test coverage in ncdevmem. Now multiple sendmsg() are tested, and sending multiple iovs in the same sendmsg() is tested. - Fixed issue where dmabuf unmapping was happening in invalid context (Stan). ==================================================================== The TX path had been dropped from the Device Memory TCP patch series post RFCv1 [1], to make that series slightly easier to review. This series rebases the implementation of the TX path on top of the net_iov/netmem framework agreed upon and merged. The motivation for the feature is thoroughly described in the docs & cover letter of the original proposal, so I don't repeat the lengthy descriptions here, but they are available in [1]. Full outline on usage of the TX path is detailed in the documentation included with this series. Test example is available via the kselftest included in the series as well. The series is relatively small, as the TX path for this feature largely piggybacks on the existing MSG_ZEROCOPY implementation. Patch Overview: --------------- 1. Documentation & tests to give high level overview of the feature being added. 1. Add netmem refcounting needed for the TX path. 2. Devmem TX netlink API. 3. Devmem TX net stack implementation. 4. Make dma-buf unbinding scheduled work to handle TX cases where it gets freed from contexts where we can't sleep. 5. Add devmem TX documentation. 6. Add scaffolding enabling driver support for netmem_tx. Add helpers, driver feature flag, and docs to enable drivers to declare netmem_tx support. 7. Guard netmem_tx against being enabled against drivers that don't support it. 8. Add devmem_tx selftests. Add TX path to ncdevmem and add a test to devmem.py. Testing: -------- Testing is very similar to devmem TCP RX path. The ncdevmem test used for the RX path is now augemented with client functionality to test TX path. * Test Setup: Kernel: net-next with this RFC and memory provider API cherry-picked locally. Hardware: Google Cloud A3 VMs. NIC: GVE with header split & RSS & flow steering support. Performance results are not included with this version, unfortunately. I'm having issues running the dma-buf exporter driver against the upstream kernel on my test setup. The issues are specific to that dma-buf exporter and do not affect this patch series. I plan to follow up this series with perf fixes if the tests point to issues once they're up and running. Special thanks to Stan who took a stab at rebasing the TX implementation on top of the netmem/net_iov framework merged. Parts of his proposal [2] that are reused as-is are forked off into their own patches to give full credit. [1] https://lore.kernel.org/netdev/20240909054318.1809580-1-almasrymina@google.… [2] https://lore.kernel.org/netdev/20240913150913.1280238-2-sdf@fomichev.me/T/#… Cc: sdf(a)fomichev.me Cc: asml.silence(a)gmail.com Cc: dw(a)davidwei.uk Cc: Jamal Hadi Salim <jhs(a)mojatatu.com> Cc: Victor Nogueira <victor(a)mojatatu.com> Cc: Pedro Tammela <pctammela(a)mojatatu.com> Cc: Samiullah Khawaja <skhawaja(a)google.com> Cc: Kuniyuki Iwashima <kuniyu(a)amazon.com> Mina Almasry (8): netmem: add niov->type attribute to distinguish different net_iov types net: add get_netmem/put_netmem support net: devmem: Implement TX path net: add devmem TCP TX documentation net: enable driver support for netmem TX gve: add netmem TX support to GVE DQO-RDA mode net: check for driver support in netmem TX selftests: ncdevmem: Implement devmem TCP TX Stanislav Fomichev (1): net: devmem: TCP tx netlink api Documentation/netlink/specs/netdev.yaml | 12 + Documentation/networking/devmem.rst | 150 ++++++++- .../networking/net_cachelines/net_device.rst | 1 + Documentation/networking/netdev-features.rst | 5 + Documentation/networking/netmem.rst | 23 +- drivers/net/ethernet/google/gve/gve_main.c | 4 + drivers/net/ethernet/google/gve/gve_tx_dqo.c | 8 +- include/linux/netdevice.h | 2 + include/linux/skbuff.h | 17 +- include/linux/skbuff_ref.h | 4 +- include/net/netmem.h | 34 +- include/net/sock.h | 1 + include/uapi/linux/netdev.h | 1 + io_uring/zcrx.c | 3 +- net/core/datagram.c | 48 ++- net/core/dev.c | 34 +- net/core/devmem.c | 139 ++++++-- net/core/devmem.h | 83 ++++- net/core/netdev-genl-gen.c | 13 + net/core/netdev-genl-gen.h | 1 + net/core/netdev-genl.c | 80 ++++- net/core/skbuff.c | 48 ++- net/core/sock.c | 6 + net/ipv4/ip_output.c | 3 +- net/ipv4/tcp.c | 50 ++- net/ipv6/ip6_output.c | 3 +- net/vmw_vsock/virtio_transport_common.c | 5 +- tools/include/uapi/linux/netdev.h | 1 + .../selftests/drivers/net/hw/devmem.py | 26 +- .../selftests/drivers/net/hw/ncdevmem.c | 300 +++++++++++++++++- 30 files changed, 1015 insertions(+), 90 deletions(-) base-commit: 21b01cb8e88ea200a834a2c114b5dc6aa378ac56 -- 2.49.0.805.g082f7c87e0-goog

1 day, 15 hours

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[PATCH] selftests/mm: compaction_test: Support platform with huge mount of memory

by Feng Tang

When running mm selftest to verify mm patches, 'compaction_test' case failed on an x86 server with 1TB memory. And the root cause is that it has too much free memory than what the test supports. The test case tries to allocate 100000 huge pages, which is about 200 GB for that x86 server, and when it succeeds, it expects it's large than 1/3 of 80% of the free memory in system. This logic only works for platform with 750 GB ( 200 / (1/3) / 80% ) or less free memory, and may raise false alarm for others. Fix it by changing the fixed page number to self-adjustable number according to the real number of free memory. Fixes: bd67d5c15cc19 ("Test compaction of mlocked memory") Signed-off-by: Feng Tang <feng.tang(a)linux.alibaba.com> --- tools/testing/selftests/mm/compaction_test.c | 19 ++++++++++++++----- 1 file changed, 14 insertions(+), 5 deletions(-) diff --git a/tools/testing/selftests/mm/compaction_test.c b/tools/testing/selftests/mm/compaction_test.c index 2c3a0eb6b22d..9bc4591c7b16 100644 --- a/tools/testing/selftests/mm/compaction_test.c +++ b/tools/testing/selftests/mm/compaction_test.c @@ -90,6 +90,8 @@ int check_compaction(unsigned long mem_free, unsigned long hugepage_size, int compaction_index = 0; char nr_hugepages[20] = {0}; char init_nr_hugepages[24] = {0}; + char target_nr_hugepages[24] = {0}; + int slen; snprintf(init_nr_hugepages, sizeof(init_nr_hugepages), "%lu", initial_nr_hugepages); @@ -106,11 +108,18 @@ int check_compaction(unsigned long mem_free, unsigned long hugepage_size, goto out; } - /* Request a large number of huge pages. The Kernel will allocate - as much as it can */ - if (write(fd, "100000", (6*sizeof(char))) != (6*sizeof(char))) { - ksft_print_msg("Failed to write 100000 to /proc/sys/vm/nr_hugepages: %s\n", - strerror(errno)); + /* + * Request huge pages for about half of the free memory. The Kernel + * will allocate as much as it can, and we expect it will get at least 1/3 + */ + nr_hugepages_ul = mem_free / hugepage_size / 2; + snprintf(target_nr_hugepages, sizeof(target_nr_hugepages), + "%lu", nr_hugepages_ul); + + slen = strlen(target_nr_hugepages); + if (write(fd, target_nr_hugepages, slen) != slen) { + ksft_print_msg("Failed to write %lu to /proc/sys/vm/nr_hugepages: %s\n", + nr_hugepages_ul, strerror(errno)); goto close_fd; } -- 2.43.5

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Linux-kselftest-mirror April 2025