kernel/linux.git/net/core/xdp.c, branch v6.12.91

xdp: allow attaching already registered memory model to xdp_rxq_info

2026-03-25T10:08:28+00:00

[ Upstream commit f65966fe0178c06065d354c22fb456fc4370b527 ] One may need to register memory model separately from xdp_rxq_info. One simple example may be XDP test run code, but in general, it might be useful when memory model registering is managed by one layer and then XDP RxQ info by a different one. Allow such scenarios by adding a simple helper which "attaches" already registered memory model to the desired xdp_rxq_info. As this is mostly needed for Page Pool, add a special function to do that for a &page_pool pointer. Reviewed-by: Toke Høiland-Jørgensen Signed-off-by: Alexander Lobakin Link: https://patch.msgid.link/20241203173733.3181246-5-aleksander.lobakin@intel.com Signed-off-by: Jakub Kicinski Stable-dep-of: 6f1a9140ecda ("net: add xmit recursion limit to tunnel xmit functions") Signed-off-by: Sasha Levin

page_pool: Move pp_magic check into helper functions

2025-06-19T13:31:42+00:00

[ Upstream commit cd3c93167da0e760b5819246eae7a4ea30fd014b ] Since we are about to stash some more information into the pp_magic field, let's move the magic signature checks into a pair of helper functions so it can be changed in one place. Reviewed-by: Mina Almasry Tested-by: Yonglong Liu Acked-by: Jesper Dangaard Brouer Reviewed-by: Ilias Apalodimas Signed-off-by: Toke Høiland-Jørgensen Link: https://patch.msgid.link/20250409-page-pool-track-dma-v9-1-6a9ef2e0cba8@redhat.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

xdp: fix invalid wait context of page_pool_destroy()

2024-07-15T03:40:21+00:00

If the driver uses a page pool, it creates a page pool with page_pool_create(). The reference count of page pool is 1 as default. A page pool will be destroyed only when a reference count reaches 0. page_pool_destroy() is used to destroy page pool, it decreases a reference count. When a page pool is destroyed, ->disconnect() is called, which is mem_allocator_disconnect(). This function internally acquires mutex_lock(). If the driver uses XDP, it registers a memory model with xdp_rxq_info_reg_mem_model(). The xdp_rxq_info_reg_mem_model() internally increases a page pool reference count if a memory model is a page pool. Now the reference count is 2. To destroy a page pool, the driver should call both page_pool_destroy() and xdp_unreg_mem_model(). The xdp_unreg_mem_model() internally calls page_pool_destroy(). Only page_pool_destroy() decreases a reference count. If a driver calls page_pool_destroy() then xdp_unreg_mem_model(), we will face an invalid wait context warning. Because xdp_unreg_mem_model() calls page_pool_destroy() with rcu_read_lock(). The page_pool_destroy() internally acquires mutex_lock(). Splat looks like: ============================= [ BUG: Invalid wait context ] 6.10.0-rc6+ #4 Tainted: G W ----------------------------- ethtool/1806 is trying to lock: ffffffff90387b90 (mem_id_lock){+.+.}-{4:4}, at: mem_allocator_disconnect+0x73/0x150 other info that might help us debug this: context-{5:5} 3 locks held by ethtool/1806: stack backtrace: CPU: 0 PID: 1806 Comm: ethtool Tainted: G W 6.10.0-rc6+ #4 f916f41f172891c800f2fed Hardware name: ASUS System Product Name/PRIME Z690-P D4, BIOS 0603 11/01/2021 Call Trace: dump_stack_lvl+0x7e/0xc0 __lock_acquire+0x1681/0x4de0 ? _printk+0x64/0xe0 ? __pfx_mark_lock.part.0+0x10/0x10 ? __pfx___lock_acquire+0x10/0x10 lock_acquire+0x1b3/0x580 ? mem_allocator_disconnect+0x73/0x150 ? __wake_up_klogd.part.0+0x16/0xc0 ? __pfx_lock_acquire+0x10/0x10 ? dump_stack_lvl+0x91/0xc0 __mutex_lock+0x15c/0x1690 ? mem_allocator_disconnect+0x73/0x150 ? __pfx_prb_read_valid+0x10/0x10 ? mem_allocator_disconnect+0x73/0x150 ? __pfx_llist_add_batch+0x10/0x10 ? console_unlock+0x193/0x1b0 ? lockdep_hardirqs_on+0xbe/0x140 ? __pfx___mutex_lock+0x10/0x10 ? tick_nohz_tick_stopped+0x16/0x90 ? __irq_work_queue_local+0x1e5/0x330 ? irq_work_queue+0x39/0x50 ? __wake_up_klogd.part.0+0x79/0xc0 ? mem_allocator_disconnect+0x73/0x150 mem_allocator_disconnect+0x73/0x150 ? __pfx_mem_allocator_disconnect+0x10/0x10 ? mark_held_locks+0xa5/0xf0 ? rcu_is_watching+0x11/0xb0 page_pool_release+0x36e/0x6d0 page_pool_destroy+0xd7/0x440 xdp_unreg_mem_model+0x1a7/0x2a0 ? __pfx_xdp_unreg_mem_model+0x10/0x10 ? kfree+0x125/0x370 ? bnxt_free_ring.isra.0+0x2eb/0x500 ? bnxt_free_mem+0x5ac/0x2500 xdp_rxq_info_unreg+0x4a/0xd0 bnxt_free_mem+0x1356/0x2500 bnxt_close_nic+0xf0/0x3b0 ? __pfx_bnxt_close_nic+0x10/0x10 ? ethnl_parse_bit+0x2c6/0x6d0 ? __pfx___nla_validate_parse+0x10/0x10 ? __pfx_ethnl_parse_bit+0x10/0x10 bnxt_set_features+0x2a8/0x3e0 __netdev_update_features+0x4dc/0x1370 ? ethnl_parse_bitset+0x4ff/0x750 ? __pfx_ethnl_parse_bitset+0x10/0x10 ? __pfx___netdev_update_features+0x10/0x10 ? mark_held_locks+0xa5/0xf0 ? _raw_spin_unlock_irqrestore+0x42/0x70 ? __pm_runtime_resume+0x7d/0x110 ethnl_set_features+0x32d/0xa20 To fix this problem, it uses rhashtable_lookup_fast() instead of rhashtable_lookup() with rcu_read_lock(). Using xa without rcu_read_lock() here is safe. xa is freed by __xdp_mem_allocator_rcu_free() and this is called by call_rcu() of mem_xa_remove(). The mem_xa_remove() is called by page_pool_destroy() if a reference count reaches 0. The xa is already protected by the reference count mechanism well in the control plane. So removing rcu_read_lock() for page_pool_destroy() is safe. Fixes: c3f812cea0d7 ("page_pool: do not release pool until inflight == 0.") Signed-off-by: Taehee Yoo Reviewed-by: Jakub Kicinski Link: https://patch.msgid.link/20240712095116.3801586-1-ap420073@gmail.com Signed-off-by: Jakub Kicinski

xdp: Remove WARN() from __xdp_reg_mem_model()

2024-06-24T11:44:02+00:00

syzkaller reports a warning in __xdp_reg_mem_model(). The warning occurs only if __mem_id_init_hash_table() returns an error. It returns the error in two cases: 1. memory allocation fails; 2. rhashtable_init() fails when some fields of rhashtable_params struct are not initialized properly. The second case cannot happen since there is a static const rhashtable_params struct with valid fields. So, warning is only triggered when there is a problem with memory allocation. Thus, there is no sense in using WARN() to handle this error and it can be safely removed. WARNING: CPU: 0 PID: 5065 at net/core/xdp.c:299 __xdp_reg_mem_model+0x2d9/0x650 net/core/xdp.c:299 CPU: 0 PID: 5065 Comm: syz-executor883 Not tainted 6.8.0-syzkaller-05271-gf99c5f563c17 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 RIP: 0010:__xdp_reg_mem_model+0x2d9/0x650 net/core/xdp.c:299 Call Trace: xdp_reg_mem_model+0x22/0x40 net/core/xdp.c:344 xdp_test_run_setup net/bpf/test_run.c:188 [inline] bpf_test_run_xdp_live+0x365/0x1e90 net/bpf/test_run.c:377 bpf_prog_test_run_xdp+0x813/0x11b0 net/bpf/test_run.c:1267 bpf_prog_test_run+0x33a/0x3b0 kernel/bpf/syscall.c:4240 __sys_bpf+0x48d/0x810 kernel/bpf/syscall.c:5649 __do_sys_bpf kernel/bpf/syscall.c:5738 [inline] __se_sys_bpf kernel/bpf/syscall.c:5736 [inline] __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5736 do_syscall_64+0xfb/0x240 entry_SYSCALL_64_after_hwframe+0x6d/0x75 Found by Linux Verification Center (linuxtesting.org) with syzkaller. Fixes: 8d5d88527587 ("xdp: rhashtable with allocator ID to pointer mapping") Signed-off-by: Daniil Dulov Signed-off-by: Daniel Borkmann Acked-by: Jesper Dangaard Brouer Link: https://lore.kernel.org/all/20240617162708.492159-1-d.dulov@aladdin.ru Link: https://lore.kernel.org/bpf/20240624080747.36858-1-d.dulov@aladdin.ru

net: move skbuff_cache(s) to net_hotdata

2024-03-08T05:12:42+00:00

skbuff_cache, skbuff_fclone_cache and skb_small_head_cache are used in rx/tx fast paths. Move them to net_hotdata for better cache locality. Signed-off-by: Eric Dumazet Acked-by: Soheil Hassas Yeganeh Reviewed-by: David Ahern Link: https://lore.kernel.org/r/20240306160031.874438-11-edumazet@google.com Signed-off-by: Jakub Kicinski

Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

2024-03-03T04:50:59+00:00

Daniel Borkmann says: ==================== pull-request: bpf-next 2024-02-29 We've added 119 non-merge commits during the last 32 day(s) which contain a total of 150 files changed, 3589 insertions(+), 995 deletions(-). The main changes are: 1) Extend the BPF verifier to enable static subprog calls in spin lock critical sections, from Kumar Kartikeya Dwivedi. 2) Fix confusing and incorrect inference of PTR_TO_CTX argument type in BPF global subprogs, from Andrii Nakryiko. 3) Larger batch of riscv BPF JIT improvements and enabling inlining of the bpf_kptr_xchg() for RV64, from Pu Lehui. 4) Allow skeleton users to change the values of the fields in struct_ops maps at runtime, from Kui-Feng Lee. 5) Extend the verifier's capabilities of tracking scalars when they are spilled to stack, especially when the spill or fill is narrowing, from Maxim Mikityanskiy & Eduard Zingerman. 6) Various BPF selftest improvements to fix errors under gcc BPF backend, from Jose E. Marchesi. 7) Avoid module loading failure when the module trying to register a struct_ops has its BTF section stripped, from Geliang Tang. 8) Annotate all kfuncs in .BTF_ids section which eventually allows for automatic kfunc prototype generation from bpftool, from Daniel Xu. 9) Several updates to the instruction-set.rst IETF standardization document, from Dave Thaler. 10) Shrink the size of struct bpf_map resp. bpf_array, from Alexei Starovoitov. 11) Initial small subset of BPF verifier prepwork for sleepable bpf_timer, from Benjamin Tissoires. 12) Fix bpftool to be more portable to musl libc by using POSIX's basename(), from Arnaldo Carvalho de Melo. 13) Add libbpf support to gcc in CORE macro definitions, from Cupertino Miranda. 14) Remove a duplicate type check in perf_event_bpf_event, from Florian Lehner. 15) Fix bpf_spin_{un,}lock BPF helpers to actually annotate them with notrace correctly, from Yonghong Song. 16) Replace the deprecated bpf_lpm_trie_key 0-length array with flexible array to fix build warnings, from Kees Cook. 17) Fix resolve_btfids cross-compilation to non host-native endianness, from Viktor Malik. * tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (119 commits) selftests/bpf: Test if shadow types work correctly. bpftool: Add an example for struct_ops map and shadow type. bpftool: Generated shadow variables for struct_ops maps. libbpf: Convert st_ops->data to shadow type. libbpf: Set btf_value_type_id of struct bpf_map for struct_ops. bpf: Replace bpf_lpm_trie_key 0-length array with flexible array bpf, arm64: use bpf_prog_pack for memory management arm64: patching: implement text_poke API bpf, arm64: support exceptions arm64: stacktrace: Implement arch_bpf_stack_walk() for the BPF JIT bpf: add is_async_callback_calling_insn() helper bpf: introduce in_sleepable() helper bpf: allow more maps in sleepable bpf programs selftests/bpf: Test case for lacking CFI stub functions. bpf: Check cfi_stubs before registering a struct_ops type. bpf: Clarify batch lookup/lookup_and_delete semantics bpf, docs: specify which BPF_ABS and BPF_IND fields were zero bpf, docs: Fix typos in instruction-set.rst selftests/bpf: update tcp_custom_syncookie to use scalar packet offset bpf: Shrink size of struct bpf_map/bpf_array. ... ==================== Link: https://lore.kernel.org/r/20240301001625.8800-1-daniel@iogearbox.net Signed-off-by: Jakub Kicinski

bpf: treewide: Annotate BPF kfuncs in BTF

2024-02-01T04:40:56+00:00

This commit marks kfuncs as such inside the .BTF_ids section. The upshot of these annotations is that we'll be able to automatically generate kfunc prototypes for downstream users. The process is as follows: 1. In source, use BTF_KFUNCS_START/END macro pair to mark kfuncs 2. During build, pahole injects into BTF a "bpf_kfunc" BTF_DECL_TAG for each function inside BTF_KFUNCS sets 3. At runtime, vmlinux or module BTF is made available in sysfs 4. At runtime, bpftool (or similar) can look at provided BTF and generate appropriate prototypes for functions with "bpf_kfunc" tag To ensure future kfunc are similarly tagged, we now also return error inside kfunc registration for untagged kfuncs. For vmlinux kfuncs, we also WARN(), as initcall machinery does not handle errors. Signed-off-by: Daniel Xu Acked-by: Benjamin Tissoires Link: https://lore.kernel.org/r/e55150ceecbf0a5d961e608941165c0bee7bc943.1706491398.git.dxu@dxuuu.xyz Signed-off-by: Alexei Starovoitov

xdp: Remove usage of the deprecated ida_simple_xx() API

2024-01-31T01:51:01+00:00

ida_alloc() and ida_free() should be preferred to the deprecated ida_simple_get() and ida_simple_remove(). Note that the upper limit of ida_simple_get() is exclusive, but the one of ida_alloc_range() is inclusive. So a -1 has been added when needed. Signed-off-by: Christophe JAILLET Link: https://lore.kernel.org/r/8e889d18a6c881b09db4650d4b30a62d76f4fe77.1705734073.git.christophe.jaillet@wanadoo.fr Signed-off-by: Jakub Kicinski

xdp: Add VLAN tag hint

2023-12-14T00:16:40+00:00

Implement functionality that enables drivers to expose VLAN tag to XDP code. VLAN tag is represented by 2 variables: - protocol ID, which is passed to bpf code in BE - VLAN TCI, in host byte order Acked-by: Stanislav Fomichev Signed-off-by: Larysa Zaremba Acked-by: Jesper Dangaard Brouer Link: https://lore.kernel.org/r/20231205210847.28460-10-larysa.zaremba@intel.com Signed-off-by: Alexei Starovoitov

bpf: Add __bpf_kfunc_{start,end}_defs macros

2023-11-02T05:33:53+00:00

BPF kfuncs are meant to be called from BPF programs. Accordingly, most kfuncs are not called from anywhere in the kernel, which the -Wmissing-prototypes warning is unhappy about. We've peppered __diag_ignore_all("-Wmissing-prototypes", ... everywhere kfuncs are defined in the codebase to suppress this warning. This patch adds two macros meant to bound one or many kfunc definitions. All existing kfunc definitions which use these __diag calls to suppress -Wmissing-prototypes are migrated to use the newly-introduced macros. A new __diag_ignore_all - for "-Wmissing-declarations" - is added to the __bpf_kfunc_start_defs macro based on feedback from Andrii on an earlier version of this patch [0] and another recent mailing list thread [1]. In the future we might need to ignore different warnings or do other kfunc-specific things. This change will make it easier to make such modifications for all kfunc defs. [0]: https://lore.kernel.org/bpf/CAEf4BzaE5dRWtK6RPLnjTW-MW9sx9K3Fn6uwqCTChK2Dcb1Xig@mail.gmail.com/ [1]: https://lore.kernel.org/bpf/ZT+2qCc%2FaXep0%2FLf@krava/ Signed-off-by: Dave Marchevsky Suggested-by: Andrii Nakryiko Acked-by: Andrii Nakryiko Cc: Jiri Olsa Acked-by: Jiri Olsa Acked-by: David Vernet Acked-by: Yafang Shao Link: https://lore.kernel.org/r/20231031215625.2343848-1-davemarchevsky@fb.com Signed-off-by: Alexei Starovoitov