- Linux-kselftest-mirror - lists.linaro.org

[PATCH bpf-next v7 0/5] Support eliding map lookup nullness

by Daniel Xu

This patch allows progs to elide a null check on statically known map lookup keys. In other words, if the verifier can statically prove that the lookup will be in-bounds, allow the prog to drop the null check. This is useful for two reasons: 1. Large numbers of nullness checks (especially when they cannot fail) unnecessarily pushes prog towards BPF_COMPLEXITY_LIMIT_JMP_SEQ. 2. It forms a tighter contract between programmer and verifier. For (1), bpftrace is starting to make heavier use of percpu scratch maps. As a result, for user scripts with large number of unrolled loops, we are starting to hit jump complexity verification errors. These percpu lookups cannot fail anyways, as we only use static key values. Eliding nullness probably results in less work for verifier as well. For (2), percpu scratch maps are often used as a larger stack, as the currrent stack is limited to 512 bytes. In these situations, it is desirable for the programmer to express: "this lookup should never fail, and if it does, it means I messed up the code". By omitting the null check, the programmer can "ask" the verifier to double check the logic. === Changelog === Changes in v7: * Use more accurate frame number when marking precise * Add test for non-stack key * Test for marking stack slot precise Changes in v6: * Use is_spilled_scalar_reg() helper and remove unnecessary comment * Add back deleted selftest with different helper to dirty dst buffer * Check size of spill is exactly key_size and update selftests * Read slot_type from correct offset into the spi * Rewrite selftests in C where possible * Mark constant map keys as precise Changes in v5: * Dropped all acks * Use s64 instead of long for const_map_key * Ensure stack slot contains spilled reg before accessing spilled_ptr * Ensure spilled reg is a scalar before accessing tnum const value * Fix verifier selftest for 32-bit write to write at 8 byte alignment to ensure spill is tracked * Introduce more precise tracking of helper stack accesses * Do constant map key extraction as part of helper argument processing and then remove duplicated stack checks * Use ret_flag instead of regs[BPF_REG_0].type * Handle STACK_ZERO * Fix bug in bpf_load_hdr_opt() arg annotation Changes in v4: * Only allow for CAP_BPF * Add test for stack growing upwards * Improve comment about stack growing upwards Changes in v3: * Check if stack is (erroneously) growing upwards * Mention in commit message why existing tests needed change Changes in v2: * Added a check for when R2 is not a ptr to stack * Added a check for when stack is uninitialized (no stack slot yet) * Updated existing tests to account for null elision * Added test case for when R2 can be both const and non-const Daniel Xu (5): bpf: verifier: Add missing newline on verbose() call bpf: tcp: Mark bpf_load_hdr_opt() arg2 as read-write bpf: verifier: Refactor helper access type tracking bpf: verifier: Support eliding map lookup nullness bpf: selftests: verifier: Add nullness elision tests kernel/bpf/verifier.c | 139 ++++++++++--- net/core/filter.c | 2 +- .../testing/selftests/bpf/progs/dynptr_fail.c | 6 +- tools/testing/selftests/bpf/progs/iters.c | 14 +- .../selftests/bpf/progs/map_kptr_fail.c | 2 +- .../selftests/bpf/progs/test_global_func10.c | 2 +- .../selftests/bpf/progs/uninit_stack.c | 5 +- .../bpf/progs/verifier_array_access.c | 188 ++++++++++++++++++ .../bpf/progs/verifier_basic_stack.c | 2 +- .../selftests/bpf/progs/verifier_const_or.c | 4 +- .../progs/verifier_helper_access_var_len.c | 12 +- .../selftests/bpf/progs/verifier_int_ptr.c | 2 +- .../selftests/bpf/progs/verifier_map_in_map.c | 2 +- .../selftests/bpf/progs/verifier_mtu.c | 2 +- .../selftests/bpf/progs/verifier_raw_stack.c | 4 +- .../selftests/bpf/progs/verifier_unpriv.c | 2 +- .../selftests/bpf/progs/verifier_var_off.c | 8 +- tools/testing/selftests/bpf/verifier/calls.c | 2 +- .../testing/selftests/bpf/verifier/map_kptr.c | 2 +- 19 files changed, 331 insertions(+), 69 deletions(-) -- 2.47.1

7 months, 2 weeks

4
11
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[PATCH] selftests/vDSO: Fix undefined CLONE_NEWTIME by including

by Purva Yeshi

Fix the build failure caused by the undefined `CLONE_NEWTIME`. Include the `linux/sched.h` header file where the function is defined to ensure successful compilation of the selftests. Signed-off-by: Purva Yeshi <purvayeshi550(a)gmail.com> --- tools/testing/selftests/vDSO/vdso_test_getrandom.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/tools/testing/selftests/vDSO/vdso_test_getrandom.c b/tools/testing/selftests/vDSO/vdso_test_getrandom.c index 95057f7567db..b2c9cf15878b 100644 --- a/tools/testing/selftests/vDSO/vdso_test_getrandom.c +++ b/tools/testing/selftests/vDSO/vdso_test_getrandom.c @@ -29,6 +29,8 @@ #include "vdso_config.h" #include "vdso_call.h" +#include <linux/sched.h> + #ifndef timespecsub #define timespecsub(tsp, usp, vsp) \ do { \ -- 2.34.1

7 months, 2 weeks

2
5
0 0

[PATCH v2 0/5] selftests/nolibc: test kernel configuration cleanups

by Thomas Weißschuh

A few cleanups and optimizations for the management of the kernel configuration. Signed-off-by: Thomas Weißschuh <linux(a)weissschuh.net> --- Changes in v2: - Rebase on current torvalds/master - Call "make defconfig" separately - Link to v1: https://lore.kernel.org/r/20250122-nolibc-config-v1-0-a697db968b49@weisssch… --- Thomas Weißschuh (5): selftests/nolibc: drop custom EXTRACONFIG functionality selftests/nolibc: drop call to prepare target selftests/nolibc: drop call to mrproper target selftests/nolibc: execute defconfig before other targets selftests/nolibc: always keep test kernel configuration up to date tools/testing/selftests/nolibc/Makefile | 17 +++++------------ tools/testing/selftests/nolibc/run-tests.sh | 7 +++---- 2 files changed, 8 insertions(+), 16 deletions(-) --- base-commit: 21266b8df5224c4f677acf9f353eecc9094731f0 change-id: 20250122-nolibc-config-d639e1612c93 Best regards, -- Thomas Weißschuh <linux(a)weissschuh.net>

7 months, 2 weeks

2
12
0 0

[PATCH 00/16] selftest/mm: Remove warnings found by adding compiler flags

by Muhammad Usama Anjum

Recently, I reviewed a patch on the mm/kselftest mailing list about a test which had obvious type mismatch fix in it. It was strange why that wasn't caught during development and when patch was accepted. This led me to discover that those extra compiler options to catch these warnings aren't being used. When I added them, I found tens of warnings in just mm suite. In this series, I'm fixing those warnings. The last check adds the compiler flags with which the warnings have been caught. Muhammad Usama Anjum (16): selftests/mm: remove argc and argv unused parameters selftests/mm: Fix unused parameter warnings selftests/mm: Fix unused parameter warnings selftests/mm: Fix type mismatch warnings selftests/mm: kselftest_harness: Fix warnings selftests/mm: cow: remove unused variables and fix type mismatch errors selftests/mm: hmm-tests: Remove always false expressions selftests/mm: guard-pages: Fix type mismatch warnings selftests/mm: hugetlb-madvise: fix type mismatch issues selftests/mm: hugepage-vmemmap: fix type mismatch warnings selftests/mm: hugetlb-read-hwpoison: Fix type mismatch warnings selftests/mm: khugepaged: Fix type mismatch warnings selftests/mm: protection_keys: Fix variables types mismatch warnings selftests/mm: thuge-gen: Fix type mismatch warnings selftests/mm: uffd-*: Fix all type mismatch warnings selftests/mm: Makefile: Add the compiler flags tools/testing/selftests/kselftest_harness.h | 6 +- tools/testing/selftests/mm/Makefile | 1 + tools/testing/selftests/mm/compaction_test.c | 4 +- tools/testing/selftests/mm/cow.c | 48 ++++++++------- tools/testing/selftests/mm/droppable.c | 2 +- tools/testing/selftests/mm/guard-pages.c | 4 +- tools/testing/selftests/mm/gup_longterm.c | 5 +- tools/testing/selftests/mm/hmm-tests.c | 4 +- tools/testing/selftests/mm/hugepage-vmemmap.c | 5 +- tools/testing/selftests/mm/hugetlb-madvise.c | 4 +- .../selftests/mm/hugetlb-read-hwpoison.c | 6 +- .../selftests/mm/hugetlb-soft-offline.c | 2 +- tools/testing/selftests/mm/hugetlb_dio.c | 2 +- .../selftests/mm/hugetlb_fault_after_madv.c | 6 +- .../selftests/mm/hugetlb_madv_vs_map.c | 8 +-- tools/testing/selftests/mm/khugepaged.c | 16 ++--- .../selftests/mm/ksm_functional_tests.c | 6 +- tools/testing/selftests/mm/ksm_tests.c | 17 +++--- tools/testing/selftests/mm/madv_populate.c | 2 +- tools/testing/selftests/mm/map_populate.c | 2 +- tools/testing/selftests/mm/memfd_secret.c | 6 +- .../testing/selftests/mm/mlock-random-test.c | 6 +- tools/testing/selftests/mm/mlock2-tests.c | 2 +- tools/testing/selftests/mm/on-fault-limit.c | 2 +- tools/testing/selftests/mm/pkey-x86.h | 4 +- .../selftests/mm/pkey_sighandler_tests.c | 21 ++++--- tools/testing/selftests/mm/protection_keys.c | 34 ++++++----- tools/testing/selftests/mm/soft-dirty.c | 8 +-- .../selftests/mm/split_huge_page_test.c | 4 +- tools/testing/selftests/mm/thuge-gen.c | 10 ++-- tools/testing/selftests/mm/uffd-common.c | 24 ++++---- tools/testing/selftests/mm/uffd-common.h | 2 +- tools/testing/selftests/mm/uffd-stress.c | 4 +- tools/testing/selftests/mm/uffd-unit-tests.c | 58 +++++++++---------- tools/testing/selftests/mm/uffd-wp-mremap.c | 2 +- .../selftests/mm/virtual_address_range.c | 2 +- 36 files changed, 180 insertions(+), 159 deletions(-) -- 2.39.5

7 months, 2 weeks

6
25
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[PATCH RFC net-next v2 0/6] Device memory TCP TX

by Mina Almasry

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 muliple 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]. Sending this series as RFC as the winder closure is immenient. I plan on reposting as non-RFC once the tree re-opens, addressing any feedback I receive in the meantime. Full outline on usage of the TX path is detailed in the documentation added in the first patch. 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. 2. Add netmem refcounting needed for the TX path. 3. Devmem TX netlink API. 4. Devmem TX net stack implementation. 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> Mina Almasry (5): net: add devmem TCP TX documentation selftests: ncdevmem: Implement devmem TCP TX net: add get_netmem/put_netmem support net: devmem: Implement TX path net: devmem: make dmabuf unbinding scheduled work Stanislav Fomichev (1): net: devmem: TCP tx netlink api Documentation/netlink/specs/netdev.yaml | 12 + Documentation/networking/devmem.rst | 144 ++++++++- include/linux/skbuff.h | 15 +- include/linux/skbuff_ref.h | 4 +- include/net/netmem.h | 3 + include/net/sock.h | 1 + include/uapi/linux/netdev.h | 1 + include/uapi/linux/uio.h | 6 +- net/core/datagram.c | 41 ++- net/core/devmem.c | 110 ++++++- net/core/devmem.h | 70 ++++- net/core/netdev-genl-gen.c | 13 + net/core/netdev-genl-gen.h | 1 + net/core/netdev-genl.c | 67 ++++- net/core/skbuff.c | 36 ++- net/core/sock.c | 8 + net/ipv4/tcp.c | 36 ++- net/vmw_vsock/virtio_transport_common.c | 3 +- tools/include/uapi/linux/netdev.h | 1 + .../selftests/drivers/net/hw/ncdevmem.c | 276 +++++++++++++++++- 20 files changed, 802 insertions(+), 46 deletions(-) -- 2.48.1.362.g079036d154-goog

7 months, 2 weeks

3
16
0 0

[PATCH RFC net-next v3 0/8] netconsole: Add support for CPU population

by Breno Leitao

The current implementation of netconsole sends all log messages in parallel, which can lead to an intermixed and interleaved output on the receiving side. This makes it challenging to demultiplex the messages and attribute them to their originating CPUs. As a result, users and developers often struggle to effectively analyze and debug the parallel log output received through netconsole. Example of a message got from produciton hosts: ------------[ cut here ]------------ ------------[ cut here ]------------ refcount_t: saturated; leaking memory. WARNING: CPU: 2 PID: 1613668 at lib/refcount.c:22 refcount_warn_saturate+0x5e/0xe0 refcount_t: addition on 0; use-after-free. WARNING: CPU: 26 PID: 4139916 at lib/refcount.c:25 refcount_warn_saturate+0x7d/0xe0 Modules linked in: bpf_preload(E) vhost_net(E) tun(E) vhost(E) This series of patches introduces a new feature to the netconsole subsystem that allows the automatic population of the CPU number in the userdata field for each log message. This enhancement provides several benefits: * Improved demultiplexing of parallel log output: When multiple CPUs are sending messages concurrently, the added CPU number in the userdata makes it easier to differentiate and attribute the messages to their originating CPUs. * Better visibility into message sources: The CPU number information gives users and developers more insight into which specific CPU a particular log message came from, which can be valuable for debugging and analysis. The changes in this series are as follows Patches:: Patch "consolidate send buffers into netconsole_target struct" ================================================= Move the static buffers to netconsole target, from static declaration in send_msg_no_fragmentation() and send_msg_fragmented(). Patch "netconsole: Rename userdata to extradata" ================================================= Create the a concept of extradata, which encompasses the concept of userdata and the upcoming sysdatao Sysdata is a new concept being added, which is basically fields that are populated by the kernel. At this time only the CPU#, but, there is a desire to add current task name, kernel release version, etc. Patch "netconsole: Helper to count number of used entries" =========================================================== Create a simple helper to count number of entries in extradata. I am separating this in a function since it will need to count userdata and sysdata. For instance, when the user adds an extra userdata, we need to check if there is space, counting the previous data entries (from userdata and cpu data) Patch "Introduce configfs helpers for sysdata features" ====================================================== Create the concept of sysdata feature in the netconsole target, and create the configfs helpers to enable the bit in nt->sysdata Patch "Include sysdata in extradata entry count" ================================================ Add the concept of sysdata when counting for available space in the buffer. This will protect users from creating new userdata/sysdata if there is no more space Patch "netconsole: add support for sysdata and CPU population" =============================================================== This is the core patch. Basically add a new option to enable automatic CPU number population in the netconsole userdata Provides a new "cpu_nr" sysfs attribute to control this feature Patch "netconsole: selftest: test CPU number auto-population" ============================================================= Expands the existing netconsole selftest to verify the CPU number auto-population functionality Ensures the received netconsole messages contain the expected "cpu=<CPU>" entry in the message. Test different permutation with userdata Patch "netconsole: docs: Add documentation for CPU number auto-population" ============================================================================= Updates the netconsole documentation to explain the new CPU number auto-population feature Provides instructions on how to enable and use the feature I believe these changes will be a valuable addition to the netconsole subsystem, enhancing its usefulness for kernel developers and users. Signed-off-by: Breno Leitao <leitao(a)debian.org> --- Changes in v3: - Moved the buffer into netconsole_target, avoiding static functions in the send path (Jakub). - Fix a documentation error (Randy Dunlap) - Created a function that handle all the extradata, consolidating it in a single place (Jakub) - Split the patch even more, trying to simplify the review. - Link to v2: https://lore.kernel.org/r/20250115-netcon_cpu-v2-0-95971b44dc56@debian.org Changes in v2: - Create the concept of extradata and sysdata. This will make the design easier to understand, and the code easier to read. * Basically extradata encompasses userdata and the new sysdata. Userdata originates from user, and sysdata originates in kernel. - Improved the test to send from a very specific CPU, which can be checked to be correct on the other side, as suggested by Jakub. - Fixed a bug where CPU # was populated at the wrong place - Link to v1: https://lore.kernel.org/r/20241113-netcon_cpu-v1-0-d187bf7c0321@debian.org --- Breno Leitao (8): netconsole: consolidate send buffers into netconsole_target struct netconsole: Rename userdata to extradata netconsole: Helper to count number of used entries netconsole: Introduce configfs helpers for sysdata features netconsole: Include sysdata in extradata entry count netconsole: add support for sysdata and CPU population netconsole: selftest: test for sysdata CPU netconsole: docs: Add documentation for CPU number auto-population Documentation/networking/netconsole.rst | 45 ++++ drivers/net/netconsole.c | 260 ++++++++++++++++----- tools/testing/selftests/drivers/net/Makefile | 1 + .../selftests/drivers/net/lib/sh/lib_netcons.sh | 17 ++ .../selftests/drivers/net/netcons_sysdata.sh | 167 +++++++++++++ 5 files changed, 426 insertions(+), 64 deletions(-) --- base-commit: fa10c9f5aa705deb43fd65623508074bee942764 change-id: 20241108-netcon_cpu-ce3917e88f4b Best regards, -- Breno Leitao <leitao(a)debian.org>

7 months, 2 weeks

3
22
0 0

[PATCH] kunit: tool: Use qboot on QEMU x86_64

by Brendan Jackman

As noted in [0], SeaBIOS (QEMU default) makes a mess of the terminal, qboot does not. It turns out this is actually useful with kunit.py, since the user is exposed to this issue if they set --raw_output=all. qboot is also faster than SeaBIOS, but it's is marginal for this usecase. [0] https://lore.kernel.org/all/CA+i-1C0wYb-gZ8Mwh3WSVpbk-LF-Uo+njVbASJPe1WXDUR… Both SeaBIOS and qboot are x86-specific. Signed-off-by: Brendan Jackman <jackmanb(a)google.com> --- tools/testing/kunit/qemu_configs/x86_64.py | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/tools/testing/kunit/qemu_configs/x86_64.py b/tools/testing/kunit/qemu_configs/x86_64.py index dc794907686304b325dbe180149169dd79bcd44f..4a6bf4e048f5b05c889e3b9b03046f14cc9b0bcc 100644 --- a/tools/testing/kunit/qemu_configs/x86_64.py +++ b/tools/testing/kunit/qemu_configs/x86_64.py @@ -7,4 +7,6 @@ CONFIG_SERIAL_8250_CONSOLE=y''', qemu_arch='x86_64', kernel_path='arch/x86/boot/bzImage', kernel_command_line='console=ttyS0', - extra_qemu_params=[]) + # qboot is faster than SeaBIOS and doesn't mess up + # the terminal. + extra_qemu_params=['-bios', 'qboot.rom']) --- base-commit: 8ea24baaaa869adeb39c6b9ce7542657a7251b56 change-id: 20250124-kunit-qboot-5201945f7e86 Best regards, -- Brendan Jackman <jackmanb(a)google.com>

7 months, 2 weeks

2
2
0 0

[PATCH bpf-next v2 0/7] bpf: Add probe_read_{kernel,user}_dynptr and copy_from_user_dynptr

by Levi Zim via B4 Relay

This series introduce the dynptr counterpart of the bpf_probe_read_{kernel,user} helpers and bpf_copy_from_user helper. These helpers are helpful for reading variable-length data from kernel memory into dynptr without going through an intermediate buffer. Link: https://lore.kernel.org/bpf/MEYP282MB2312CFCE5F7712FDE313215AC64D2@MEYP282M… Suggested-by: Andrii Nakryiko <andrii.nakryiko(a)gmail.com> Signed-off-by: Levi Zim <rsworktech(a)outlook.com> --- Changes in v2: - Add missing bpf-next prefix. I forgot it in the initial series. Sorry about that. - Link to v1: https://lore.kernel.org/r/20250125-bpf_dynptr_probe-v1-0-c3cb121f6951@outlo… --- Levi Zim (7): bpf: Implement bpf_probe_read_kernel_dynptr helper bpf: Implement bpf_probe_read_user_dynptr helper bpf: Implement bpf_copy_from_user_dynptr helper tools headers UAPI: Update tools's copy of bpf.h header selftests/bpf: probe_read_kernel_dynptr test selftests/bpf: probe_read_user_dynptr test selftests/bpf: copy_from_user_dynptr test include/linux/bpf.h | 3 + include/uapi/linux/bpf.h | 49 ++++++++++ kernel/bpf/helpers.c | 53 ++++++++++- kernel/trace/bpf_trace.c | 72 ++++++++++++++ tools/include/uapi/linux/bpf.h | 49 ++++++++++ tools/testing/selftests/bpf/prog_tests/dynptr.c | 45 ++++++++- tools/testing/selftests/bpf/progs/dynptr_success.c | 106 +++++++++++++++++++++ 7 files changed, 374 insertions(+), 3 deletions(-) --- base-commit: d0d106a2bd21499901299160744e5fe9f4c83ddb change-id: 20250124-bpf_dynptr_probe-ab483c554f1a Best regards, -- Levi Zim <rsworktech(a)outlook.com>

7 months, 2 weeks

6
20
0 0

[PATCH v2 net] udp: gso: do not drop small packets when PMTU reduces

by Yan Zhai

Commit 4094871db1d6 ("udp: only do GSO if # of segs > 1") avoided GSO for small packets. But the kernel currently dismisses GSO requests only after checking MTU/PMTU on gso_size. This means any packets, regardless of their payload sizes, could be dropped when PMTU becomes smaller than requested gso_size. We encountered this issue in production and it caused a reliability problem that new QUIC connection cannot be established before PMTU cache expired, while non GSO sockets still worked fine at the same time. Ideally, do not check any GSO related constraints when payload size is smaller than requested gso_size, and return EMSGSIZE instead of EINVAL on MTU/PMTU check failure to be more specific on the error cause. Fixes: 4094871db1d6 ("udp: only do GSO if # of segs > 1") Signed-off-by: Yan Zhai <yan(a)cloudflare.com> -- v1->v2: add a missing MTU check when fall back to no GSO mode suggested by Willem de Bruijn <willemdebruijn.kernel(a)gmail.com>; Fixed up commit message to be more precise. v1: https://lore.kernel.org/all/Z5cgWh%2F6bRQm9vVU@debian.debian/ --- net/ipv4/udp.c | 28 +++++++++++++++++++--------- net/ipv6/udp.c | 28 +++++++++++++++++++--------- tools/testing/selftests/net/udpgso.c | 14 ++++++++++++++ 3 files changed, 52 insertions(+), 18 deletions(-) diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c index c472c9a57cf6..0b5010238d05 100644 --- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -1141,9 +1141,20 @@ static int udp_send_skb(struct sk_buff *skb, struct flowi4 *fl4, const int hlen = skb_network_header_len(skb) + sizeof(struct udphdr); + if (datalen <= cork->gso_size) { + /* + * check MTU again: it's skipped previously when + * gso_size != 0 + */ + if (hlen + datalen > cork->fragsize) { + kfree_skb(skb); + return -EMSGSIZE; + } + goto no_gso; + } if (hlen + cork->gso_size > cork->fragsize) { kfree_skb(skb); - return -EINVAL; + return -EMSGSIZE; } if (datalen > cork->gso_size * UDP_MAX_SEGMENTS) { kfree_skb(skb); @@ -1158,17 +1169,16 @@ static int udp_send_skb(struct sk_buff *skb, struct flowi4 *fl4, return -EIO; } - if (datalen > cork->gso_size) { - skb_shinfo(skb)->gso_size = cork->gso_size; - skb_shinfo(skb)->gso_type = SKB_GSO_UDP_L4; - skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(datalen, - cork->gso_size); + skb_shinfo(skb)->gso_size = cork->gso_size; + skb_shinfo(skb)->gso_type = SKB_GSO_UDP_L4; + skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(datalen, + cork->gso_size); - /* Don't checksum the payload, skb will get segmented */ - goto csum_partial; - } + /* Don't checksum the payload, skb will get segmented */ + goto csum_partial; } +no_gso: if (is_udplite) /* UDP-Lite */ csum = udplite_csum(skb); diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c index 6671daa67f4f..d97befa7f80d 100644 --- a/net/ipv6/udp.c +++ b/net/ipv6/udp.c @@ -1389,9 +1389,20 @@ static int udp_v6_send_skb(struct sk_buff *skb, struct flowi6 *fl6, const int hlen = skb_network_header_len(skb) + sizeof(struct udphdr); + if (datalen <= cork->gso_size) { + /* + * check MTU again: it's skipped previously when + * gso_size != 0 + */ + if (hlen + datalen > cork->fragsize) { + kfree_skb(skb); + return -EMSGSIZE; + } + goto no_gso; + } if (hlen + cork->gso_size > cork->fragsize) { kfree_skb(skb); - return -EINVAL; + return -EMSGSIZE; } if (datalen > cork->gso_size * UDP_MAX_SEGMENTS) { kfree_skb(skb); @@ -1406,17 +1417,16 @@ static int udp_v6_send_skb(struct sk_buff *skb, struct flowi6 *fl6, return -EIO; } - if (datalen > cork->gso_size) { - skb_shinfo(skb)->gso_size = cork->gso_size; - skb_shinfo(skb)->gso_type = SKB_GSO_UDP_L4; - skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(datalen, - cork->gso_size); + skb_shinfo(skb)->gso_size = cork->gso_size; + skb_shinfo(skb)->gso_type = SKB_GSO_UDP_L4; + skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(datalen, + cork->gso_size); - /* Don't checksum the payload, skb will get segmented */ - goto csum_partial; - } + /* Don't checksum the payload, skb will get segmented */ + goto csum_partial; } +no_gso: if (is_udplite) csum = udplite_csum(skb); else if (udp_get_no_check6_tx(sk)) { /* UDP csum disabled */ diff --git a/tools/testing/selftests/net/udpgso.c b/tools/testing/selftests/net/udpgso.c index 3f2fca02fec5..fb73f1c331fb 100644 --- a/tools/testing/selftests/net/udpgso.c +++ b/tools/testing/selftests/net/udpgso.c @@ -102,6 +102,13 @@ struct testcase testcases_v4[] = { .gso_len = CONST_MSS_V4, .r_num_mss = 1, }, + { + /* datalen <= MSS < gso_len: will fall back to no GSO */ + .tlen = CONST_MSS_V4, + .gso_len = CONST_MSS_V4 + 1, + .r_num_mss = 0, + .r_len_last = CONST_MSS_V4, + }, { /* send a single MSS + 1B */ .tlen = CONST_MSS_V4 + 1, @@ -205,6 +212,13 @@ struct testcase testcases_v6[] = { .gso_len = CONST_MSS_V6, .r_num_mss = 1, }, + { + /* datalen <= MSS < gso_len: will fall back to no GSO */ + .tlen = CONST_MSS_V6, + .gso_len = CONST_MSS_V6 + 1, + .r_num_mss = 0, + .r_len_last = CONST_MSS_V6, + }, { /* send a single MSS + 1B */ .tlen = CONST_MSS_V6 + 1, -- 2.30.2

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[RFC net-next 0/2] netdevgenl: Add an xsk attribute to queues

by Joe Damato

Greetings: This is an attempt to followup on something Jakub asked me about [1], adding an xsk attribute to queues and more clearly documenting which queues are linked to NAPIs... But: 1. I couldn't pick a good "thing" to expose as "xsk", so I chose 0 or 1. Happy to take suggestions on what might be better to expose for the xsk queue attribute. 2. I create a silly C helper program to create an XDP socket in order to add a new test to queues.py. I'm not particularly good at python programming, so there's probably a better way to do this. Notably, python does not seem to have a socket.AF_XDP, so I needed the C helper to make a socket and bind it to a queue to perform the test. Tested this on my mlx5 machine and the test seems to pass. Happy to take any suggestions / feedback on this one; sorry in advance if I missed many obvious better ways to do things. Thanks, Joe [1]: https://lore.kernel.org/netdev/20250113143109.60afa59a@kernel.org/ Joe Damato (2): netdev-genl: Add an XSK attribute to queues selftests: drv-net: Test queue xsk attribute Documentation/netlink/specs/netdev.yaml | 10 ++- include/uapi/linux/netdev.h | 1 + net/core/netdev-genl.c | 6 ++ tools/include/uapi/linux/netdev.h | 1 + tools/testing/selftests/drivers/.gitignore | 1 + tools/testing/selftests/drivers/net/Makefile | 3 + tools/testing/selftests/drivers/net/queues.py | 32 ++++++- .../selftests/drivers/net/xdp_helper.c | 90 +++++++++++++++++++ 8 files changed, 141 insertions(+), 3 deletions(-) create mode 100644 tools/testing/selftests/drivers/net/xdp_helper.c base-commit: 0ad9617c78acbc71373fb341a6f75d4012b01d69 -- 2.25.1

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