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2023-10-10bpf: Fix verifier log for async callback return valuesDavid Vernet1-3/+3
The verifier, as part of check_return_code(), verifies that async callbacks such as from e.g. timers, will return 0. It does this by correctly checking that R0->var_off is in tnum_const(0), which effectively checks that it's in a range of 0. If this condition fails, however, it prints an error message which says that the value should have been in (0x0; 0x1). This results in possibly confusing output such as the following in which an async callback returns 1: At async callback the register R0 has value (0x1; 0x0) should have been in (0x0; 0x1) The fix is easy -- we should just pass the tnum_const(0) as the correct range to verbose_invalid_scalar(), which will then print the following: At async callback the register R0 has value (0x1; 0x0) should have been in (0x0; 0x0) Fixes: bfc6bb74e4f1 ("bpf: Implement verifier support for validation of async callbacks.") Signed-off-by: David Vernet <void@manifault.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20231009161414.235829-1-void@manifault.com
2023-10-07bpf: Refuse unused attributes in bpf_prog_{attach,detach}Lorenz Bauer1-5/+14
The recently added tcx attachment extended the BPF UAPI for attaching and detaching by a couple of fields. Those fields are currently only supported for tcx, other types like cgroups and flow dissector silently ignore the new fields except for the new flags. This is problematic once we extend bpf_mprog to older attachment types, since it's hard to figure out whether the syscall really was successful if the kernel silently ignores non-zero values. Explicitly reject non-zero fields relevant to bpf_mprog for attachment types which don't use the latter yet. Fixes: e420bed02507 ("bpf: Add fd-based tcx multi-prog infra with link support") Signed-off-by: Lorenz Bauer <lmb@isovalent.com> Co-developed-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/r/20231006220655.1653-3-daniel@iogearbox.net Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2023-10-07bpf: Handle bpf_mprog_query with NULL entryDaniel Borkmann2-11/+7
Improve consistency for bpf_mprog_query() API and let the latter also handle a NULL entry as can be the case for tcx. Instead of returning -ENOENT, we copy a count of 0 and revision of 1 to user space, so that this can be fed into a subsequent bpf_mprog_attach() call as expected_revision. A BPF self- test as part of this series has been added to assert this case. Suggested-by: Lorenz Bauer <lmb@isovalent.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/r/20231006220655.1653-2-daniel@iogearbox.net Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2023-10-07bpf: Fix BPF_PROG_QUERY last field checkDaniel Borkmann1-1/+1
While working on the ebpf-go [0] library integration for bpf_mprog and tcx, Lorenz noticed that two subsequent BPF_PROG_QUERY requests currently fail. A typical workflow is to first gather the bpf_mprog count without passing program/ link arrays, followed by the second request which contains the actual array pointers. The initial call populates count and revision fields. The second call gets rejected due to a BPF_PROG_QUERY_LAST_FIELD bug which should point to query.revision instead of query.link_attach_flags since the former is really the last member. It was not noticed in libbpf as bpf_prog_query_opts() always calls bpf(2) with an on-stack bpf_attr that is memset() each time (and therefore query.revision was reset to zero). [0] https://ebpf-go.dev Fixes: e420bed02507 ("bpf: Add fd-based tcx multi-prog infra with link support") Reported-by: Lorenz Bauer <lmb@isovalent.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/r/20231006220655.1653-1-daniel@iogearbox.net Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2023-09-30bpf: Use kmalloc_size_roundup() to adjust size_indexHou Tao1-25/+19
Commit d52b59315bf5 ("bpf: Adjust size_index according to the value of KMALLOC_MIN_SIZE") uses KMALLOC_MIN_SIZE to adjust size_index, but as reported by Nathan, the adjustment is not enough, because __kmalloc_minalign() also decides the minimal alignment of slab object as shown in new_kmalloc_cache() and its value may be greater than KMALLOC_MIN_SIZE (e.g., 64 bytes vs 8 bytes under a riscv QEMU VM). Instead of invoking __kmalloc_minalign() in bpf subsystem to find the maximal alignment, just using kmalloc_size_roundup() directly to get the corresponding slab object size for each allocation size. If these two sizes are unmatched, adjust size_index to select a bpf_mem_cache with unit_size equal to the object_size of the underlying slab cache for the allocation size. Fixes: 822fb26bdb55 ("bpf: Add a hint to allocated objects.") Reported-by: Nathan Chancellor <nathan@kernel.org> Closes: https://lore.kernel.org/bpf/20230914181407.GA1000274@dev-arch.thelio-3990X/ Signed-off-by: Hou Tao <houtao1@huawei.com> Tested-by: Emil Renner Berthing <emil.renner.berthing@canonical.com> Link: https://lore.kernel.org/r/20230928101558.2594068-1-houtao@huaweicloud.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-09-30bpf, mprog: Fix maximum program check on mprog attachmentDaniel Borkmann1-0/+3
After Paul's recent improvement to syzkaller to improve coverage for bpf_mprog and tcx, it hit a splat that the program limit was surpassed. What happened is that the maximum number of progs got added, followed by another prog add request which adds with BPF_F_BEFORE flag relative to the last program in the array. The idx >= bpf_mprog_max() check in bpf_mprog_attach() still passes because the index is below the maximum but the maximum will be surpassed. We need to add a check upfront for insertions to catch this situation. Fixes: 053c8e1f235d ("bpf: Add generic attach/detach/query API for multi-progs") Reported-by: syzbot+baa44e3dbbe48e05c1ad@syzkaller.appspotmail.com Reported-by: syzbot+b97d20ed568ce0951a06@syzkaller.appspotmail.com Reported-by: syzbot+2558ca3567a77b7af4e3@syzkaller.appspotmail.com Co-developed-by: Nikolay Aleksandrov <razor@blackwall.org> Signed-off-by: Nikolay Aleksandrov <razor@blackwall.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Tested-by: syzbot+baa44e3dbbe48e05c1ad@syzkaller.appspotmail.com Tested-by: syzbot+b97d20ed568ce0951a06@syzkaller.appspotmail.com Link: https://github.com/google/syzkaller/pull/4207 Link: https://lore.kernel.org/bpf/20230929204121.20305-1-daniel@iogearbox.net
2023-09-20bpf: unconditionally reset backtrack_state masks on global func exitAndrii Nakryiko1-5/+3
In mark_chain_precision() logic, when we reach the entry to a global func, it is expected that R1-R5 might be still requested to be marked precise. This would correspond to some integer input arguments being tracked as precise. This is all expected and handled as a special case. What's not expected is that we'll leave backtrack_state structure with some register bits set. This is because for subsequent precision propagations backtrack_state is reused without clearing masks, as all code paths are carefully written in a way to leave empty backtrack_state with zeroed out masks, for speed. The fix is trivial, we always clear register bit in the register mask, and then, optionally, set reg->precise if register is SCALAR_VALUE type. Reported-by: Chris Mason <clm@meta.com> Fixes: be2ef8161572 ("bpf: allow precision tracking for programs with subprogs") Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20230918210110.2241458-1-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-09-16Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpfDavid S. Miller5-19/+123
Alexei Starovoitov says: ==================== The following pull-request contains BPF updates for your *net* tree. We've added 21 non-merge commits during the last 8 day(s) which contain a total of 21 files changed, 450 insertions(+), 36 deletions(-). The main changes are: 1) Adjust bpf_mem_alloc buckets to match ksize(), from Hou Tao. 2) Check whether override is allowed in kprobe mult, from Jiri Olsa. 3) Fix btf_id symbol generation with ld.lld, from Jiri and Nick. 4) Fix potential deadlock when using queue and stack maps from NMI, from Toke Høiland-Jørgensen. Please consider pulling these changes from: git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf.git Thanks a lot! Also thanks to reporters, reviewers and testers of commits in this pull-request: Alan Maguire, Biju Das, Björn Töpel, Dan Carpenter, Daniel Borkmann, Eduard Zingerman, Hsin-Wei Hung, Marcus Seyfarth, Nathan Chancellor, Satya Durga Srinivasu Prabhala, Song Liu, Stephen Rothwell ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2023-09-15bpf: Skip unit_size checking for global per-cpu allocatorHou Tao1-0/+7
For global per-cpu allocator, the size of free object in free list doesn't match with unit_size and now there is no way to get the size of per-cpu pointer saved in free object, so just skip the checking. Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Closes: https://lore.kernel.org/bpf/20230913133436.0eeec4cb@canb.auug.org.au/ Signed-off-by: Hou Tao <houtao1@huawei.com> Tested-by: Biju Das <biju.das.jz@bp.renesas.com> Link: https://lore.kernel.org/r/20230913135943.3137292-1-houtao@huaweicloud.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-09-12bpf, cgroup: fix multiple kernel-doc warningsRandy Dunlap1-6/+7
Fix missing or extra function parameter kernel-doc warnings in cgroup.c: kernel/bpf/cgroup.c:1359: warning: Excess function parameter 'type' description in '__cgroup_bpf_run_filter_skb' kernel/bpf/cgroup.c:1359: warning: Function parameter or member 'atype' not described in '__cgroup_bpf_run_filter_skb' kernel/bpf/cgroup.c:1439: warning: Excess function parameter 'type' description in '__cgroup_bpf_run_filter_sk' kernel/bpf/cgroup.c:1439: warning: Function parameter or member 'atype' not described in '__cgroup_bpf_run_filter_sk' kernel/bpf/cgroup.c:1467: warning: Excess function parameter 'type' description in '__cgroup_bpf_run_filter_sock_addr' kernel/bpf/cgroup.c:1467: warning: Function parameter or member 'atype' not described in '__cgroup_bpf_run_filter_sock_addr' kernel/bpf/cgroup.c:1512: warning: Excess function parameter 'type' description in '__cgroup_bpf_run_filter_sock_ops' kernel/bpf/cgroup.c:1512: warning: Function parameter or member 'atype' not described in '__cgroup_bpf_run_filter_sock_ops' kernel/bpf/cgroup.c:1685: warning: Excess function parameter 'type' description in '__cgroup_bpf_run_filter_sysctl' kernel/bpf/cgroup.c:1685: warning: Function parameter or member 'atype' not described in '__cgroup_bpf_run_filter_sysctl' kernel/bpf/cgroup.c:795: warning: Excess function parameter 'type' description in '__cgroup_bpf_replace' kernel/bpf/cgroup.c:795: warning: Function parameter or member 'new_prog' not described in '__cgroup_bpf_replace' Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Martin KaFai Lau <martin.lau@linux.dev> Cc: bpf@vger.kernel.org Cc: Alexei Starovoitov <ast@kernel.org> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20230912060812.1715-1-rdunlap@infradead.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-09-12bpf: Fix a erroneous check after snprintf()Christophe JAILLET1-1/+1
snprintf() does not return negative error code on error, it returns the number of characters which *would* be generated for the given input. Fix the error handling check. Fixes: 57539b1c0ac2 ("bpf: Enable annotating trusted nested pointers") Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Link: https://lore.kernel.org/r/393bdebc87b22563c08ace094defa7160eb7a6c0.1694190795.git.christophe.jaillet@wanadoo.fr Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-09-12bpf: Avoid dummy bpf_offload_netdev in __bpf_prog_dev_bound_initEduard Zingerman1-5/+7
Fix for a bug observable under the following sequence of events: 1. Create a network device that does not support XDP offload. 2. Load a device bound XDP program with BPF_F_XDP_DEV_BOUND_ONLY flag (such programs are not offloaded). 3. Load a device bound XDP program with zero flags (such programs are offloaded). At step (2) __bpf_prog_dev_bound_init() associates with device (1) a dummy bpf_offload_netdev struct with .offdev field set to NULL. At step (3) __bpf_prog_dev_bound_init() would reuse dummy struct allocated at step (2). However, downstream usage of the bpf_offload_netdev assumes that .offdev field can't be NULL, e.g. in bpf_prog_offload_verifier_prep(). Adjust __bpf_prog_dev_bound_init() to require bpf_offload_netdev with non-NULL .offdev for offloaded BPF programs. Fixes: 2b3486bc2d23 ("bpf: Introduce device-bound XDP programs") Reported-by: syzbot+291100dcb32190ec02a8@syzkaller.appspotmail.com Closes: https://lore.kernel.org/bpf/000000000000d97f3c060479c4f8@google.com/ Signed-off-by: Eduard Zingerman <eddyz87@gmail.com> Link: https://lore.kernel.org/r/20230912005539.2248244-2-eddyz87@gmail.com Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2023-09-12bpf: Avoid deadlock when using queue and stack maps from NMIToke Høiland-Jørgensen1-3/+18
Sysbot discovered that the queue and stack maps can deadlock if they are being used from a BPF program that can be called from NMI context (such as one that is attached to a perf HW counter event). To fix this, add an in_nmi() check and use raw_spin_trylock() in NMI context, erroring out if grabbing the lock fails. Fixes: f1a2e44a3aec ("bpf: add queue and stack maps") Reported-by: Hsin-Wei Hung <hsinweih@uci.edu> Tested-by: Hsin-Wei Hung <hsinweih@uci.edu> Co-developed-by: Hsin-Wei Hung <hsinweih@uci.edu> Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com> Link: https://lore.kernel.org/r/20230911132815.717240-1-toke@redhat.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-09-11bpf: Ensure unit_size is matched with slab cache object sizeHou Tao1-2/+31
Add extra check in bpf_mem_alloc_init() to ensure the unit_size of bpf_mem_cache is matched with the object_size of underlying slab cache. If these two sizes are unmatched, print a warning once and return -EINVAL in bpf_mem_alloc_init(), so the mismatch can be found early and the potential issue can be prevented. Suggested-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Hou Tao <houtao1@huawei.com> Link: https://lore.kernel.org/r/20230908133923.2675053-4-houtao@huaweicloud.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-09-11bpf: Don't prefill for unused bpf_mem_cacheHou Tao1-2/+14
When the unit_size of a bpf_mem_cache is unmatched with the object_size of the underlying slab cache, the bpf_mem_cache will not be used, and the allocation will be redirected to a bpf_mem_cache with a bigger unit_size instead, so there is no need to prefill for these unused bpf_mem_caches. Signed-off-by: Hou Tao <houtao1@huawei.com> Link: https://lore.kernel.org/r/20230908133923.2675053-3-houtao@huaweicloud.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-09-11bpf: Adjust size_index according to the value of KMALLOC_MIN_SIZEHou Tao1-0/+38
The following warning was reported when running "./test_progs -a link_api -a linked_list" on a RISC-V QEMU VM: ------------[ cut here ]------------ WARNING: CPU: 3 PID: 261 at kernel/bpf/memalloc.c:342 bpf_mem_refill Modules linked in: bpf_testmod(OE) CPU: 3 PID: 261 Comm: test_progs- ... 6.5.0-rc5-01743-gdcb152bb8328 #2 Hardware name: riscv-virtio,qemu (DT) epc : bpf_mem_refill+0x1fc/0x206 ra : irq_work_single+0x68/0x70 epc : ffffffff801b1bc4 ra : ffffffff8015fe84 sp : ff2000000001be20 gp : ffffffff82d26138 tp : ff6000008477a800 t0 : 0000000000046600 t1 : ffffffff812b6ddc t2 : 0000000000000000 s0 : ff2000000001be70 s1 : ff5ffffffffe8998 a0 : ff5ffffffffe8998 a1 : ff600003fef4b000 a2 : 000000000000003f a3 : ffffffff80008250 a4 : 0000000000000060 a5 : 0000000000000080 a6 : 0000000000000000 a7 : 0000000000735049 s2 : ff5ffffffffe8998 s3 : 0000000000000022 s4 : 0000000000001000 s5 : 0000000000000007 s6 : ff5ffffffffe8570 s7 : ffffffff82d6bd30 s8 : 000000000000003f s9 : ffffffff82d2c5e8 s10: 000000000000ffff s11: ffffffff82d2c5d8 t3 : ffffffff81ea8f28 t4 : 0000000000000000 t5 : ff6000008fd28278 t6 : 0000000000040000 [<ffffffff801b1bc4>] bpf_mem_refill+0x1fc/0x206 [<ffffffff8015fe84>] irq_work_single+0x68/0x70 [<ffffffff8015feb4>] irq_work_run_list+0x28/0x36 [<ffffffff8015fefa>] irq_work_run+0x38/0x66 [<ffffffff8000828a>] handle_IPI+0x3a/0xb4 [<ffffffff800a5c3a>] handle_percpu_devid_irq+0xa4/0x1f8 [<ffffffff8009fafa>] generic_handle_domain_irq+0x28/0x36 [<ffffffff800ae570>] ipi_mux_process+0xac/0xfa [<ffffffff8000a8ea>] sbi_ipi_handle+0x2e/0x88 [<ffffffff8009fafa>] generic_handle_domain_irq+0x28/0x36 [<ffffffff807ee70e>] riscv_intc_irq+0x36/0x4e [<ffffffff812b5d3a>] handle_riscv_irq+0x54/0x86 [<ffffffff812b6904>] do_irq+0x66/0x98 ---[ end trace 0000000000000000 ]--- The warning is due to WARN_ON_ONCE(tgt->unit_size != c->unit_size) in free_bulk(). The direct reason is that a object is allocated and freed by bpf_mem_caches with different unit_size. The root cause is that KMALLOC_MIN_SIZE is 64 and there is no 96-bytes slab cache in the specific VM. When linked_list test allocates a 72-bytes object through bpf_obj_new(), bpf_global_ma will allocate it from a bpf_mem_cache with 96-bytes unit_size, but this bpf_mem_cache is backed by 128-bytes slab cache. When the object is freed, bpf_mem_free() uses ksize() to choose the corresponding bpf_mem_cache. Because the object is allocated from 128-bytes slab cache, ksize() returns 128, bpf_mem_free() chooses a 128-bytes bpf_mem_cache to free the object and triggers the warning. A similar warning will also be reported when using CONFIG_SLAB instead of CONFIG_SLUB in a x86-64 kernel. Because CONFIG_SLUB defines KMALLOC_MIN_SIZE as 8 but CONFIG_SLAB defines KMALLOC_MIN_SIZE as 32. An alternative fix is to use kmalloc_size_round() in bpf_mem_alloc() to choose a bpf_mem_cache which has the same unit_size with the backing slab cache, but it may introduce performance degradation, so fix the warning by adjusting the indexes in size_index according to the value of KMALLOC_MIN_SIZE just like setup_kmalloc_cache_index_table() does. Fixes: 822fb26bdb55 ("bpf: Add a hint to allocated objects.") Reported-by: Björn Töpel <bjorn@kernel.org> Closes: https://lore.kernel.org/bpf/87jztjmmy4.fsf@all.your.base.are.belong.to.us Signed-off-by: Hou Tao <houtao1@huawei.com> Link: https://lore.kernel.org/r/20230908133923.2675053-2-houtao@huaweicloud.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-09-10Merge tag 'riscv-for-linus-6.6-mw2-2' of ↵Linus Torvalds1-4/+4
git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux Pull more RISC-V updates from Palmer Dabbelt: - The kernel now dynamically probes for misaligned access speed, as opposed to relying on a table of known implementations. - Support for non-coherent devices on systems using the Andes AX45MP core, including the RZ/Five SoCs. - Support for the V extension in ptrace(), again. - Support for KASLR. - Support for the BPF prog pack allocator in RISC-V. - A handful of bug fixes and cleanups. * tag 'riscv-for-linus-6.6-mw2-2' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (25 commits) soc: renesas: Kconfig: For ARCH_R9A07G043 select the required configs if dependencies are met riscv: Kconfig.errata: Add dependency for RISCV_SBI in ERRATA_ANDES config riscv: Kconfig.errata: Drop dependency for MMU in ERRATA_ANDES_CMO config riscv: Kconfig: Select DMA_DIRECT_REMAP only if MMU is enabled bpf, riscv: use prog pack allocator in the BPF JIT riscv: implement a memset like function for text riscv: extend patch_text_nosync() for multiple pages bpf: make bpf_prog_pack allocator portable riscv: libstub: Implement KASLR by using generic functions libstub: Fix compilation warning for rv32 arm64: libstub: Move KASLR handling functions to kaslr.c riscv: Dump out kernel offset information on panic riscv: Introduce virtual kernel mapping KASLR RISC-V: Add ptrace support for vectors soc: renesas: Kconfig: Select the required configs for RZ/Five SoC cache: Add L2 cache management for Andes AX45MP RISC-V core dt-bindings: cache: andestech,ax45mp-cache: Add DT binding documentation for L2 cache controller riscv: mm: dma-noncoherent: nonstandard cache operations support riscv: errata: Add Andes alternative ports riscv: asm: vendorid_list: Add Andes Technology to the vendors list ...
2023-09-08Merge patch series "bpf, riscv: use BPF prog pack allocator in BPF JIT"Palmer Dabbelt1-4/+4
Puranjay Mohan <puranjay12@gmail.com> says: Here is some data to prove the V2 fixes the problem: Without this series: root@rv-selftester:~/src/kselftest/bpf# time ./test_tag test_tag: OK (40945 tests) real 7m47.562s user 0m24.145s sys 6m37.064s With this series applied: root@rv-selftester:~/src/selftest/bpf# time ./test_tag test_tag: OK (40945 tests) real 7m29.472s user 0m25.865s sys 6m18.401s BPF programs currently consume a page each on RISCV. For systems with many BPF programs, this adds significant pressure to instruction TLB. High iTLB pressure usually causes slow down for the whole system. Song Liu introduced the BPF prog pack allocator[1] to mitigate the above issue. It packs multiple BPF programs into a single huge page. It is currently only enabled for the x86_64 BPF JIT. I enabled this allocator on the ARM64 BPF JIT[2]. It is being reviewed now. This patch series enables the BPF prog pack allocator for the RISCV BPF JIT. ====================================================== Performance Analysis of prog pack allocator on RISCV64 ====================================================== Test setup: =========== Host machine: Debian GNU/Linux 11 (bullseye) Qemu Version: QEMU emulator version 8.0.3 (Debian 1:8.0.3+dfsg-1) u-boot-qemu Version: 2023.07+dfsg-1 opensbi Version: 1.3-1 To test the performance of the BPF prog pack allocator on RV, a stresser tool[4] linked below was built. This tool loads 8 BPF programs on the system and triggers 5 of them in an infinite loop by doing system calls. The runner script starts 20 instances of the above which loads 8*20=160 BPF programs on the system, 5*20=100 of which are being constantly triggered. The script is passed a command which would be run in the above environment. The script was run with following perf command: ./run.sh "perf stat -a \ -e iTLB-load-misses \ -e dTLB-load-misses \ -e dTLB-store-misses \ -e instructions \ --timeout 60000" The output of the above command is discussed below before and after enabling the BPF prog pack allocator. The tests were run on qemu-system-riscv64 with 8 cpus, 16G memory. The rootfs was created using Bjorn's riscv-cross-builder[5] docker container linked below. Results ======= Before enabling prog pack allocator: ------------------------------------ Performance counter stats for 'system wide': 4939048 iTLB-load-misses 5468689 dTLB-load-misses 465234 dTLB-store-misses 1441082097998 instructions 60.045791200 seconds time elapsed After enabling prog pack allocator: ----------------------------------- Performance counter stats for 'system wide': 3430035 iTLB-load-misses 5008745 dTLB-load-misses 409944 dTLB-store-misses 1441535637988 instructions 60.046296600 seconds time elapsed Improvements in metrics ======================= It was expected that the iTLB-load-misses would decrease as now a single huge page is used to keep all the BPF programs compared to a single page for each program earlier. -------------------------------------------- The improvement in iTLB-load-misses: -30.5 % -------------------------------------------- I repeated this expriment more than 100 times in different setups and the improvement was always greater than 30%. This patch series is boot tested on the Starfive VisionFive 2 board[6]. The performance analysis was not done on the board because it doesn't expose iTLB-load-misses, etc. The stresser program was run on the board to test the loading and unloading of BPF programs [1] https://lore.kernel.org/bpf/20220204185742.271030-1-song@kernel.org/ [2] https://lore.kernel.org/all/20230626085811.3192402-1-puranjay12@gmail.com/ [3] https://lore.kernel.org/all/20230626085811.3192402-2-puranjay12@gmail.com/ [4] https://github.com/puranjaymohan/BPF-Allocator-Bench [5] https://github.com/bjoto/riscv-cross-builder [6] https://www.starfivetech.com/en/site/boards * b4-shazam-merge: bpf, riscv: use prog pack allocator in the BPF JIT riscv: implement a memset like function for text riscv: extend patch_text_nosync() for multiple pages bpf: make bpf_prog_pack allocator portable Link: https://lore.kernel.org/r/20230831131229.497941-1-puranjay12@gmail.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-09-08Merge tag 'net-6.6-rc1' of ↵Linus Torvalds3-38/+18
git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net Pull networking updates from Jakub Kicinski: "Including fixes from netfilter and bpf. Current release - regressions: - eth: stmmac: fix failure to probe without MAC interface specified Current release - new code bugs: - docs: netlink: fix missing classic_netlink doc reference Previous releases - regressions: - deal with integer overflows in kmalloc_reserve() - use sk_forward_alloc_get() in sk_get_meminfo() - bpf_sk_storage: fix the missing uncharge in sk_omem_alloc - fib: avoid warn splat in flow dissector after packet mangling - skb_segment: call zero copy functions before using skbuff frags - eth: sfc: check for zero length in EF10 RX prefix Previous releases - always broken: - af_unix: fix msg_controllen test in scm_pidfd_recv() for MSG_CMSG_COMPAT - xsk: fix xsk_build_skb() dereferencing possible ERR_PTR() - netfilter: - nft_exthdr: fix non-linear header modification - xt_u32, xt_sctp: validate user space input - nftables: exthdr: fix 4-byte stack OOB write - nfnetlink_osf: avoid OOB read - one more fix for the garbage collection work from last release - igmp: limit igmpv3_newpack() packet size to IP_MAX_MTU - bpf, sockmap: fix preempt_rt splat when using raw_spin_lock_t - handshake: fix null-deref in handshake_nl_done_doit() - ip: ignore dst hint for multipath routes to ensure packets are hashed across the nexthops - phy: micrel: - correct bit assignments for cable test errata - disable EEE according to the KSZ9477 errata Misc: - docs/bpf: document compile-once-run-everywhere (CO-RE) relocations - Revert "net: macsec: preserve ingress frame ordering", it appears to have been developed against an older kernel, problem doesn't exist upstream" * tag 'net-6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (95 commits) net: enetc: distinguish error from valid pointers in enetc_fixup_clear_rss_rfs() Revert "net: team: do not use dynamic lockdep key" net: hns3: remove GSO partial feature bit net: hns3: fix the port information display when sfp is absent net: hns3: fix invalid mutex between tc qdisc and dcb ets command issue net: hns3: fix debugfs concurrency issue between kfree buffer and read net: hns3: fix byte order conversion issue in hclge_dbg_fd_tcam_read() net: hns3: Support query tx timeout threshold by debugfs net: hns3: fix tx timeout issue net: phy: Provide Module 4 KSZ9477 errata (DS80000754C) netfilter: nf_tables: Unbreak audit log reset netfilter: ipset: add the missing IP_SET_HASH_WITH_NET0 macro for ip_set_hash_netportnet.c netfilter: nft_set_rbtree: skip sync GC for new elements in this transaction netfilter: nf_tables: uapi: Describe NFTA_RULE_CHAIN_ID netfilter: nfnetlink_osf: avoid OOB read netfilter: nftables: exthdr: fix 4-byte stack OOB write selftests/bpf: Check bpf_sk_storage has uncharged sk_omem_alloc bpf: bpf_sk_storage: Fix the missing uncharge in sk_omem_alloc bpf: bpf_sk_storage: Fix invalid wait context lockdep report s390/bpf: Pass through tail call counter in trampolines ...
2023-09-06bpf: make bpf_prog_pack allocator portablePuranjay Mohan1-4/+4
The bpf_prog_pack allocator currently uses module_alloc() and module_memfree() to allocate and free memory. This is not portable because different architectures use different methods for allocating memory for BPF programs. Like ARM64 and riscv use vmalloc()/vfree(). Use bpf_jit_alloc_exec() and bpf_jit_free_exec() for memory management in bpf_prog_pack allocator. Other architectures can override these with their implementation and will be able to use bpf_prog_pack directly. On architectures that don't override bpf_jit_alloc/free_exec() this is basically a NOP. Signed-off-by: Puranjay Mohan <puranjay12@gmail.com> Acked-by: Song Liu <song@kernel.org> Acked-by: Björn Töpel <bjorn@kernel.org> Tested-by: Björn Töpel <bjorn@rivosinc.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/r/20230831131229.497941-2-puranjay12@gmail.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-09-06bpf: bpf_sk_storage: Fix the missing uncharge in sk_omem_allocMartin KaFai Lau1-1/+1
The commit c83597fa5dc6 ("bpf: Refactor some inode/task/sk storage functions for reuse"), refactored the bpf_{sk,task,inode}_storage_free() into bpf_local_storage_unlink_nolock() which then later renamed to bpf_local_storage_destroy(). The commit accidentally passed the "bool uncharge_mem = false" argument to bpf_selem_unlink_storage_nolock() which then stopped the uncharge from happening to the sk->sk_omem_alloc. This missing uncharge only happens when the sk is going away (during __sk_destruct). This patch fixes it by always passing "uncharge_mem = true". It is a noop to the task/inode/cgroup storage because they do not have the map_local_storage_(un)charge enabled in the map_ops. A followup patch will be done in bpf-next to remove the uncharge_mem argument. A selftest is added in the next patch. Fixes: c83597fa5dc6 ("bpf: Refactor some inode/task/sk storage functions for reuse") Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20230901231129.578493-3-martin.lau@linux.dev
2023-09-06bpf: bpf_sk_storage: Fix invalid wait context lockdep reportMartin KaFai Lau1-33/+14
'./test_progs -t test_local_storage' reported a splat: [ 27.137569] ============================= [ 27.138122] [ BUG: Invalid wait context ] [ 27.138650] 6.5.0-03980-gd11ae1b16b0a #247 Tainted: G O [ 27.139542] ----------------------------- [ 27.140106] test_progs/1729 is trying to lock: [ 27.140713] ffff8883ef047b88 (stock_lock){-.-.}-{3:3}, at: local_lock_acquire+0x9/0x130 [ 27.141834] other info that might help us debug this: [ 27.142437] context-{5:5} [ 27.142856] 2 locks held by test_progs/1729: [ 27.143352] #0: ffffffff84bcd9c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire+0x4/0x40 [ 27.144492] #1: ffff888107deb2c0 (&storage->lock){..-.}-{2:2}, at: bpf_local_storage_update+0x39e/0x8e0 [ 27.145855] stack backtrace: [ 27.146274] CPU: 0 PID: 1729 Comm: test_progs Tainted: G O 6.5.0-03980-gd11ae1b16b0a #247 [ 27.147550] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014 [ 27.149127] Call Trace: [ 27.149490] <TASK> [ 27.149867] dump_stack_lvl+0x130/0x1d0 [ 27.152609] dump_stack+0x14/0x20 [ 27.153131] __lock_acquire+0x1657/0x2220 [ 27.153677] lock_acquire+0x1b8/0x510 [ 27.157908] local_lock_acquire+0x29/0x130 [ 27.159048] obj_cgroup_charge+0xf4/0x3c0 [ 27.160794] slab_pre_alloc_hook+0x28e/0x2b0 [ 27.161931] __kmem_cache_alloc_node+0x51/0x210 [ 27.163557] __kmalloc+0xaa/0x210 [ 27.164593] bpf_map_kzalloc+0xbc/0x170 [ 27.165147] bpf_selem_alloc+0x130/0x510 [ 27.166295] bpf_local_storage_update+0x5aa/0x8e0 [ 27.167042] bpf_fd_sk_storage_update_elem+0xdb/0x1a0 [ 27.169199] bpf_map_update_value+0x415/0x4f0 [ 27.169871] map_update_elem+0x413/0x550 [ 27.170330] __sys_bpf+0x5e9/0x640 [ 27.174065] __x64_sys_bpf+0x80/0x90 [ 27.174568] do_syscall_64+0x48/0xa0 [ 27.175201] entry_SYSCALL_64_after_hwframe+0x6e/0xd8 [ 27.175932] RIP: 0033:0x7effb40e41ad [ 27.176357] Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d8 [ 27.179028] RSP: 002b:00007ffe64c21fc8 EFLAGS: 00000202 ORIG_RAX: 0000000000000141 [ 27.180088] RAX: ffffffffffffffda RBX: 00007ffe64c22768 RCX: 00007effb40e41ad [ 27.181082] RDX: 0000000000000020 RSI: 00007ffe64c22008 RDI: 0000000000000002 [ 27.182030] RBP: 00007ffe64c21ff0 R08: 0000000000000000 R09: 00007ffe64c22788 [ 27.183038] R10: 0000000000000064 R11: 0000000000000202 R12: 0000000000000000 [ 27.184006] R13: 00007ffe64c22788 R14: 00007effb42a1000 R15: 0000000000000000 [ 27.184958] </TASK> It complains about acquiring a local_lock while holding a raw_spin_lock. It means it should not allocate memory while holding a raw_spin_lock since it is not safe for RT. raw_spin_lock is needed because bpf_local_storage supports tracing context. In particular for task local storage, it is easy to get a "current" task PTR_TO_BTF_ID in tracing bpf prog. However, task (and cgroup) local storage has already been moved to bpf mem allocator which can be used after raw_spin_lock. The splat is for the sk storage. For sk (and inode) storage, it has not been moved to bpf mem allocator. Using raw_spin_lock or not, kzalloc(GFP_ATOMIC) could theoretically be unsafe in tracing context. However, the local storage helper requires a verifier accepted sk pointer (PTR_TO_BTF_ID), it is hypothetical if that (mean running a bpf prog in a kzalloc unsafe context and also able to hold a verifier accepted sk pointer) could happen. This patch avoids kzalloc after raw_spin_lock to silent the splat. There is an existing kzalloc before the raw_spin_lock. At that point, a kzalloc is very likely required because a lookup has just been done before. Thus, this patch always does the kzalloc before acquiring the raw_spin_lock and remove the later kzalloc usage after the raw_spin_lock. After this change, it will have a charge and then uncharge during the syscall bpf_map_update_elem() code path. This patch opts for simplicity and not continue the old optimization to save one charge and uncharge. This issue is dated back to the very first commit of bpf_sk_storage which had been refactored multiple times to create task, inode, and cgroup storage. This patch uses a Fixes tag with a more recent commit that should be easier to do backport. Fixes: b00fa38a9c1c ("bpf: Enable non-atomic allocations in local storage") Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20230901231129.578493-2-martin.lau@linux.dev
2023-09-06bpf: Assign bpf_tramp_run_ctx::saved_run_ctx before recursion check.Sebastian Andrzej Siewior2-4/+2
__bpf_prog_enter_recur() assigns bpf_tramp_run_ctx::saved_run_ctx before performing the recursion check which means in case of a recursion __bpf_prog_exit_recur() uses the previously set bpf_tramp_run_ctx::saved_run_ctx value. __bpf_prog_enter_sleepable_recur() assigns bpf_tramp_run_ctx::saved_run_ctx after the recursion check which means in case of a recursion __bpf_prog_exit_sleepable_recur() uses an uninitialized value. This does not look right. If I read the entry trampoline code right, then bpf_tramp_run_ctx isn't initialized upfront. Align __bpf_prog_enter_sleepable_recur() with __bpf_prog_enter_recur() and set bpf_tramp_run_ctx::saved_run_ctx before the recursion check is made. Remove the assignment of saved_run_ctx in kern_sys_bpf() since it happens a few cycles later. Fixes: e384c7b7b46d0 ("bpf, x86: Create bpf_tramp_run_ctx on the caller thread's stack") Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Jiri Olsa <jolsa@kernel.org> Link: https://lore.kernel.org/bpf/20230830080405.251926-3-bigeasy@linutronix.de
2023-09-06bpf: Invoke __bpf_prog_exit_sleepable_recur() on recursion in kern_sys_bpf().Sebastian Andrzej Siewior1-0/+1
If __bpf_prog_enter_sleepable_recur() detects recursion then it returns 0 without undoing rcu_read_lock_trace(), migrate_disable() or decrementing the recursion counter. This is fine in the JIT case because the JIT code will jump in the 0 case to the end and invoke the matching exit trampoline (__bpf_prog_exit_sleepable_recur()). This is not the case in kern_sys_bpf() which returns directly to the caller with an error code. Add __bpf_prog_exit_sleepable_recur() as clean up in the recursion case. Fixes: b1d18a7574d0d ("bpf: Extend sys_bpf commands for bpf_syscall programs.") Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Jiri Olsa <jolsa@kernel.org> Link: https://lore.kernel.org/bpf/20230830080405.251926-2-bigeasy@linutronix.de
2023-09-02Merge tag 'probes-v6.6' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull probes updates from Masami Hiramatsu: - kprobes: use struct_size() for variable size kretprobe_instance data structure. - eprobe: Simplify trace_eprobe list iteration. - probe events: Data structure field access support on BTF argument. - Update BTF argument support on the functions in the kernel loadable modules (only loaded modules are supported). - Move generic BTF access function (search function prototype and get function parameters) to a separated file. - Add a function to search a member of data structure in BTF. - Support accessing BTF data structure member from probe args by C-like arrow('->') and dot('.') operators. e.g. 't sched_switch next=next->pid vruntime=next->se.vruntime' - Support accessing BTF data structure member from $retval. e.g. 'f getname_flags%return +0($retval->name):string' - Add string type checking if BTF type info is available. This will reject if user specify ":string" type for non "char pointer" type. - Automatically assume the fprobe event as a function return event if $retval is used. - selftests/ftrace: Add BTF data field access test cases. - Documentation: Update fprobe event example with BTF data field. * tag 'probes-v6.6' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: Documentation: tracing: Update fprobe event example with BTF field selftests/ftrace: Add BTF fields access testcases tracing/fprobe-event: Assume fprobe is a return event by $retval tracing/probes: Add string type check with BTF tracing/probes: Support BTF field access from $retval tracing/probes: Support BTF based data structure field access tracing/probes: Add a function to search a member of a struct/union tracing/probes: Move finding func-proto API and getting func-param API to trace_btf tracing/probes: Support BTF argument on module functions tracing/eprobe: Iterate trace_eprobe directly kernel: kprobes: Use struct_size()
2023-08-29Merge tag 'net-next-6.6' of ↵Linus Torvalds23-765/+2466
git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next Pull networking updates from Paolo Abeni: "Core: - Increase size limits for to-be-sent skb frag allocations. This allows tun, tap devices and packet sockets to better cope with large writes operations - Store netdevs in an xarray, to simplify iterating over netdevs - Refactor nexthop selection for multipath routes - Improve sched class lifetime handling - Add backup nexthop ID support for bridge - Implement drop reasons support in openvswitch - Several data races annotations and fixes - Constify the sk parameter of routing functions - Prepend kernel version to netconsole message Protocols: - Implement support for TCP probing the peer being under memory pressure - Remove hard coded limitation on IPv6 specific info placement inside the socket struct - Get rid of sysctl_tcp_adv_win_scale and use an auto-estimated per socket scaling factor - Scaling-up the IPv6 expired route GC via a separated list of expiring routes - In-kernel support for the TLS alert protocol - Better support for UDP reuseport with connected sockets - Add NEXT-C-SID support for SRv6 End.X behavior, reducing the SR header size - Get rid of additional ancillary per MPTCP connection struct socket - Implement support for BPF-based MPTCP packet schedulers - Format MPTCP subtests selftests results in TAP - Several new SMC 2.1 features including unique experimental options, max connections per lgr negotiation, max links per lgr negotiation BPF: - Multi-buffer support in AF_XDP - Add multi uprobe BPF links for attaching multiple uprobes and usdt probes, which is significantly faster and saves extra fds - Implement an fd-based tc BPF attach API (TCX) and BPF link support on top of it - Add SO_REUSEPORT support for TC bpf_sk_assign - Support new instructions from cpu v4 to simplify the generated code and feature completeness, for x86, arm64, riscv64 - Support defragmenting IPv(4|6) packets in BPF - Teach verifier actual bounds of bpf_get_smp_processor_id() and fix perf+libbpf issue related to custom section handling - Introduce bpf map element count and enable it for all program types - Add a BPF hook in sys_socket() to change the protocol ID from IPPROTO_TCP to IPPROTO_MPTCP to cover migration for legacy - Introduce bpf_me_mcache_free_rcu() and fix OOM under stress - Add uprobe support for the bpf_get_func_ip helper - Check skb ownership against full socket - Support for up to 12 arguments in BPF trampoline - Extend link_info for kprobe_multi and perf_event links Netfilter: - Speed-up process exit by aborting ruleset validation if a fatal signal is pending - Allow NLA_POLICY_MASK to be used with BE16/BE32 types Driver API: - Page pool optimizations, to improve data locality and cache usage - Introduce ndo_hwtstamp_get() and ndo_hwtstamp_set() to avoid the need for raw ioctl() handling in drivers - Simplify genetlink dump operations (doit/dumpit) providing them the common information already populated in struct genl_info - Extend and use the yaml devlink specs to [re]generate the split ops - Introduce devlink selective dumps, to allow SF filtering SF based on handle and other attributes - Add yaml netlink spec for netlink-raw families, allow route, link and address related queries via the ynl tool - Remove phylink legacy mode support - Support offload LED blinking to phy - Add devlink port function attributes for IPsec New hardware / drivers: - Ethernet: - Broadcom ASP 2.0 (72165) ethernet controller - MediaTek MT7988 SoC - Texas Instruments AM654 SoC - Texas Instruments IEP driver - Atheros qca8081 phy - Marvell 88Q2110 phy - NXP TJA1120 phy - WiFi: - MediaTek mt7981 support - Can: - Kvaser SmartFusion2 PCI Express devices - Allwinner T113 controllers - Texas Instruments tcan4552/4553 chips - Bluetooth: - Intel Gale Peak - Qualcomm WCN3988 and WCN7850 - NXP AW693 and IW624 - Mediatek MT2925 Drivers: - Ethernet NICs: - nVidia/Mellanox: - mlx5: - support UDP encapsulation in packet offload mode - IPsec packet offload support in eswitch mode - improve aRFS observability by adding new set of counters - extends MACsec offload support to cover RoCE traffic - dynamic completion EQs - mlx4: - convert to use auxiliary bus instead of custom interface logic - Intel - ice: - implement switchdev bridge offload, even for LAG interfaces - implement SRIOV support for LAG interfaces - igc: - add support for multiple in-flight TX timestamps - Broadcom: - bnxt: - use the unified RX page pool buffers for XDP and non-XDP - use the NAPI skb allocation cache - OcteonTX2: - support Round Robin scheduling HTB offload - TC flower offload support for SPI field - Freescale: - add XDP_TX feature support - AMD: - ionic: add support for PCI FLR event - sfc: - basic conntrack offload - introduce eth, ipv4 and ipv6 pedit offloads - ST Microelectronics: - stmmac: maximze PTP timestamping resolution - Virtual NICs: - Microsoft vNIC: - batch ringing RX queue doorbell on receiving packets - add page pool for RX buffers - Virtio vNIC: - add per queue interrupt coalescing support - Google vNIC: - add queue-page-list mode support - Ethernet high-speed switches: - nVidia/Mellanox (mlxsw): - add port range matching tc-flower offload - permit enslavement to netdevices with uppers - Ethernet embedded switches: - Marvell (mv88e6xxx): - convert to phylink_pcs - Renesas: - r8A779fx: add speed change support - rzn1: enables vlan support - Ethernet PHYs: - convert mv88e6xxx to phylink_pcs - WiFi: - Qualcomm Wi-Fi 7 (ath12k): - extremely High Throughput (EHT) PHY support - RealTek (rtl8xxxu): - enable AP mode for: RTL8192FU, RTL8710BU (RTL8188GU), RTL8192EU and RTL8723BU - RealTek (rtw89): - Introduce Time Averaged SAR (TAS) support - Connector: - support for event filtering" * tag 'net-next-6.6' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1806 commits) net: ethernet: mtk_wed: minor change in wed_{tx,rx}info_show net: ethernet: mtk_wed: add some more info in wed_txinfo_show handler net: stmmac: clarify difference between "interface" and "phy_interface" r8152: add vendor/device ID pair for D-Link DUB-E250 devlink: move devlink_notify_register/unregister() to dev.c devlink: move small_ops definition into netlink.c devlink: move tracepoint definitions into core.c devlink: push linecard related code into separate file devlink: push rate related code into separate file devlink: push trap related code into separate file devlink: use tracepoint_enabled() helper devlink: push region related code into separate file devlink: push param related code into separate file devlink: push resource related code into separate file devlink: push dpipe related code into separate file devlink: move and rename devlink_dpipe_send_and_alloc_skb() helper devlink: push shared buffer related code into separate file devlink: push port related code into separate file devlink: push object register/unregister notifications into separate helpers inet: fix IP_TRANSPARENT error handling ...
2023-08-28Merge tag 'v6.6-vfs.ctime' of ↵Linus Torvalds1-4/+2
git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs Pull vfs timestamp updates from Christian Brauner: "This adds VFS support for multi-grain timestamps and converts tmpfs, xfs, ext4, and btrfs to use them. This carries acks from all relevant filesystems. The VFS always uses coarse-grained timestamps when updating the ctime and mtime after a change. This has the benefit of allowing filesystems to optimize away a lot of metadata updates, down to around 1 per jiffy, even when a file is under heavy writes. Unfortunately, this has always been an issue when we're exporting via NFSv3, which relies on timestamps to validate caches. A lot of changes can happen in a jiffy, so timestamps aren't sufficient to help the client decide to invalidate the cache. Even with NFSv4, a lot of exported filesystems don't properly support a change attribute and are subject to the same problems with timestamp granularity. Other applications have similar issues with timestamps (e.g., backup applications). If we were to always use fine-grained timestamps, that would improve the situation, but that becomes rather expensive, as the underlying filesystem would have to log a lot more metadata updates. This introduces fine-grained timestamps that are used when they are actively queried. This uses the 31st bit of the ctime tv_nsec field to indicate that something has queried the inode for the mtime or ctime. When this flag is set, on the next mtime or ctime update, the kernel will fetch a fine-grained timestamp instead of the usual coarse-grained one. As POSIX generally mandates that when the mtime changes, the ctime must also change the kernel always stores normalized ctime values, so only the first 30 bits of the tv_nsec field are ever used. Filesytems can opt into this behavior by setting the FS_MGTIME flag in the fstype. Filesystems that don't set this flag will continue to use coarse-grained timestamps. Various preparatory changes, fixes and cleanups are included: - Fixup all relevant places where POSIX requires updating ctime together with mtime. This is a wide-range of places and all maintainers provided necessary Acks. - Add new accessors for inode->i_ctime directly and change all callers to rely on them. Plain accesses to inode->i_ctime are now gone and it is accordingly rename to inode->__i_ctime and commented as requiring accessors. - Extend generic_fillattr() to pass in a request mask mirroring in a sense the statx() uapi. This allows callers to pass in a request mask to only get a subset of attributes filled in. - Rework timestamp updates so it's possible to drop the @now parameter the update_time() inode operation and associated helpers. - Add inode_update_timestamps() and convert all filesystems to it removing a bunch of open-coding" * tag 'v6.6-vfs.ctime' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (107 commits) btrfs: convert to multigrain timestamps ext4: switch to multigrain timestamps xfs: switch to multigrain timestamps tmpfs: add support for multigrain timestamps fs: add infrastructure for multigrain timestamps fs: drop the timespec64 argument from update_time xfs: have xfs_vn_update_time gets its own timestamp fat: make fat_update_time get its own timestamp fat: remove i_version handling from fat_update_time ubifs: have ubifs_update_time use inode_update_timestamps btrfs: have it use inode_update_timestamps fs: drop the timespec64 arg from generic_update_time fs: pass the request_mask to generic_fillattr fs: remove silly warning from current_time gfs2: fix timestamp handling on quota inodes fs: rename i_ctime field to __i_ctime selinux: convert to ctime accessor functions security: convert to ctime accessor functions apparmor: convert to ctime accessor functions sunrpc: convert to ctime accessor functions ...
2023-08-25bpf: Allow bpf_spin_{lock,unlock} in sleepable progsDave Marchevsky2-6/+5
Commit 9e7a4d9831e8 ("bpf: Allow LSM programs to use bpf spin locks") disabled bpf_spin_lock usage in sleepable progs, stating: Sleepable LSM programs can be preempted which means that allowng spin locks will need more work (disabling preemption and the verifier ensuring that no sleepable helpers are called when a spin lock is held). This patch disables preemption before grabbing bpf_spin_lock. The second requirement above "no sleepable helpers are called when a spin lock is held" is implicitly enforced by current verifier logic due to helper calls in spin_lock CS being disabled except for a few exceptions, none of which sleep. Due to above preemption changes, bpf_spin_lock CS can also be considered a RCU CS, so verifier's in_rcu_cs check is modified to account for this. Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com> Link: https://lore.kernel.org/r/20230821193311.3290257-7-davemarchevsky@fb.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-08-25bpf: Consider non-owning refs to refcounted nodes RCU protectedDave Marchevsky1-1/+12
An earlier patch in the series ensures that the underlying memory of nodes with bpf_refcount - which can have multiple owners - is not reused until RCU grace period has elapsed. This prevents use-after-free with non-owning references that may point to recently-freed memory. While RCU read lock is held, it's safe to dereference such a non-owning ref, as by definition RCU GP couldn't have elapsed and therefore underlying memory couldn't have been reused. From the perspective of verifier "trustedness" non-owning refs to refcounted nodes are now trusted only in RCU CS and therefore should no longer pass is_trusted_reg, but rather is_rcu_reg. Let's mark them MEM_RCU in order to reflect this new state. Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com> Link: https://lore.kernel.org/r/20230821193311.3290257-6-davemarchevsky@fb.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-08-25bpf: Reenable bpf_refcount_acquireDave Marchevsky1-4/+1
Now that all reported issues are fixed, bpf_refcount_acquire can be turned back on. Also reenable all bpf_refcount-related tests which were disabled. This a revert of: * commit f3514a5d6740 ("selftests/bpf: Disable newly-added 'owner' field test until refcount re-enabled") * commit 7deca5eae833 ("bpf: Disable bpf_refcount_acquire kfunc calls until race conditions are fixed") Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com> Acked-by: Yonghong Song <yonghong.song@linux.dev> Link: https://lore.kernel.org/r/20230821193311.3290257-5-davemarchevsky@fb.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-08-25bpf: Use bpf_mem_free_rcu when bpf_obj_dropping refcounted nodesDave Marchevsky1-1/+5
This is the final fix for the use-after-free scenario described in commit 7793fc3babe9 ("bpf: Make bpf_refcount_acquire fallible for non-owning refs"). That commit, by virtue of changing bpf_refcount_acquire's refcount_inc to a refcount_inc_not_zero, fixed the "refcount incr on 0" splat. The not_zero check in refcount_inc_not_zero, though, still occurs on memory that could have been free'd and reused, so the commit didn't properly fix the root cause. This patch actually fixes the issue by free'ing using the recently-added bpf_mem_free_rcu, which ensures that the memory is not reused until RCU grace period has elapsed. If that has happened then there are no non-owning references alive that point to the recently-free'd memory, so it can be safely reused. Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com> Acked-by: Yonghong Song <yonghong.song@linux.dev> Link: https://lore.kernel.org/r/20230821193311.3290257-4-davemarchevsky@fb.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-08-25bpf: Ensure kptr_struct_meta is non-NULL for collection insert and ↵Dave Marchevsky1-0/+14
refcount_acquire It's straightforward to prove that kptr_struct_meta must be non-NULL for any valid call to these kfuncs: * btf_parse_struct_metas in btf.c creates a btf_struct_meta for any struct in user BTF with a special field (e.g. bpf_refcount, {rb,list}_node). These are stored in that BTF's struct_meta_tab. * __process_kf_arg_ptr_to_graph_node in verifier.c ensures that nodes have {rb,list}_node field and that it's at the correct offset. Similarly, check_kfunc_args ensures bpf_refcount field existence for node param to bpf_refcount_acquire. * So a btf_struct_meta must have been created for the struct type of node param to these kfuncs * That BTF and its struct_meta_tab are guaranteed to still be around. Any arbitrary {rb,list} node the BPF program interacts with either: came from bpf_obj_new or a collection removal kfunc in the same program, in which case the BTF is associated with the program and still around; or came from bpf_kptr_xchg, in which case the BTF was associated with the map and is still around Instead of silently continuing with NULL struct_meta, which caused confusing bugs such as those addressed by commit 2140a6e3422d ("bpf: Set kptr_struct_meta for node param to list and rbtree insert funcs"), let's error out. Then, at runtime, we can confidently say that the implementations of these kfuncs were given a non-NULL kptr_struct_meta, meaning that special-field-specific functionality like bpf_obj_free_fields and the bpf_obj_drop change introduced later in this series are guaranteed to execute. This patch doesn't change functionality, just makes it easier to reason about existing functionality. Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com> Acked-by: Yonghong Song <yonghong.song@linux.dev> Link: https://lore.kernel.org/r/20230821193311.3290257-2-davemarchevsky@fb.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-08-24bpf: Remove a WARN_ON_ONCE warning related to local kptrYonghong Song1-1/+0
Currently, in function bpf_obj_free_fields(), for local kptr, a warning will be issued if the struct does not contain any special fields. But actually the kernel seems totally okay with a local kptr without any special fields. Permitting no special fields also aligns with future percpu kptr which also allows no special fields. Acked-by: Dave Marchevsky <davemarchevsky@fb.com> Signed-off-by: Yonghong Song <yonghong.song@linux.dev> Link: https://lore.kernel.org/r/20230824063417.201925-1-yonghong.song@linux.dev Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-08-23bpf: Fix issue in verifying allow_ptr_leaksYafang Shao1-8/+9
After we converted the capabilities of our networking-bpf program from cap_sys_admin to cap_net_admin+cap_bpf, our networking-bpf program failed to start. Because it failed the bpf verifier, and the error log is "R3 pointer comparison prohibited". A simple reproducer as follows, SEC("cls-ingress") int ingress(struct __sk_buff *skb) { struct iphdr *iph = (void *)(long)skb->data + sizeof(struct ethhdr); if ((long)(iph + 1) > (long)skb->data_end) return TC_ACT_STOLEN; return TC_ACT_OK; } Per discussion with Yonghong and Alexei [1], comparison of two packet pointers is not a pointer leak. This patch fixes it. Our local kernel is 6.1.y and we expect this fix to be backported to 6.1.y, so stable is CCed. [1]. https://lore.kernel.org/bpf/CAADnVQ+Nmspr7Si+pxWn8zkE7hX-7s93ugwC+94aXSy4uQ9vBg@mail.gmail.com/ Suggested-by: Yonghong Song <yonghong.song@linux.dev> Suggested-by: Alexei Starovoitov <alexei.starovoitov@gmail.com> Signed-off-by: Yafang Shao <laoar.shao@gmail.com> Acked-by: Eduard Zingerman <eddyz87@gmail.com> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20230823020703.3790-2-laoar.shao@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-08-23tracing/probes: Support BTF argument on module functionsMasami Hiramatsu (Google)1-1/+1
Since the btf returned from bpf_get_btf_vmlinux() only covers functions in the vmlinux, BTF argument is not available on the functions in the modules. Use bpf_find_btf_id() instead of bpf_get_btf_vmlinux()+btf_find_name_kind() so that BTF argument can find the correct struct btf and btf_type in it. With this fix, fprobe events can use `$arg*` on module functions as below # grep nf_log_ip_packet /proc/kallsyms ffffffffa0005c00 t nf_log_ip_packet [nf_log_syslog] ffffffffa0005bf0 t __pfx_nf_log_ip_packet [nf_log_syslog] # echo 'f nf_log_ip_packet $arg*' > dynamic_events # cat dynamic_events f:fprobes/nf_log_ip_packet__entry nf_log_ip_packet net=net pf=pf hooknum=hooknum skb=skb in=in out=out loginfo=loginfo prefix=prefix To support the module's btf which is removable, the struct btf needs to be ref-counted. So this also records the btf in the traceprobe_parse_context and returns the refcount when the parse has done. Link: https://lore.kernel.org/all/169272154223.160970.3507930084247934031.stgit@devnote2/ Suggested-by: Alexei Starovoitov <alexei.starovoitov@gmail.com> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-08-22bpf: Fix check_func_arg_reg_off bug for graph root/nodeKumar Kartikeya Dwivedi1-11/+0
The commit being fixed introduced a hunk into check_func_arg_reg_off that bypasses reg->off == 0 enforcement when offset points to a graph node or root. This might possibly be done for treating bpf_rbtree_remove and others as KF_RELEASE and then later check correct reg->off in helper argument checks. But this is not the case, those helpers are already not KF_RELEASE and permit non-zero reg->off and verify it later to match the subobject in BTF type. However, this logic leads to bpf_obj_drop permitting free of register arguments with non-zero offset when they point to a graph root or node within them, which is not ok. For instance: struct foo { int i; int j; struct bpf_rb_node node; }; struct foo *f = bpf_obj_new(typeof(*f)); if (!f) ... bpf_obj_drop(f); // OK bpf_obj_drop(&f->i); // still ok from verifier PoV bpf_obj_drop(&f->node); // Not OK, but permitted right now Fix this by dropping the whole part of code altogether. Fixes: 6a3cd3318ff6 ("bpf: Migrate release_on_unlock logic to non-owning ref semantics") Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Link: https://lore.kernel.org/r/20230822175140.1317749-2-memxor@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-08-22bpf: Fix a bpf_kptr_xchg() issue with local kptrYonghong Song1-10/+15
When reviewing local percpu kptr support, Alexei discovered a bug wherea bpf_kptr_xchg() may succeed even if the map value kptr type and locally allocated obj type do not match ([1]). Missed struct btf_id comparison is the reason for the bug. This patch added such struct btf_id comparison and will flag verification failure if types do not match. [1] https://lore.kernel.org/bpf/20230819002907.io3iphmnuk43xblu@macbook-pro-8.dhcp.thefacebook.com/#t Reported-by: Alexei Starovoitov <ast@kernel.org> Fixes: 738c96d5e2e3 ("bpf: Allow local kptrs to be exchanged via bpf_kptr_xchg") Signed-off-by: Yonghong Song <yonghong.song@linux.dev> Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Link: https://lore.kernel.org/r/20230822050053.2886960-1-yonghong.song@linux.dev Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-08-22bpf: Add pid filter support for uprobe_multi linkJiri Olsa1-1/+1
Adding support to specify pid for uprobe_multi link and the uprobes are created only for task with given pid value. Using the consumer.filter filter callback for that, so the task gets filtered during the uprobe installation. We still need to check the task during runtime in the uprobe handler, because the handler could get executed if there's another system wide consumer on the same uprobe (thanks Oleg for the insight). Cc: Oleg Nesterov <oleg@redhat.com> Reviewed-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Jiri Olsa <jolsa@kernel.org> Acked-by: Yonghong Song <yonghong.song@linux.dev> Link: https://lore.kernel.org/r/20230809083440.3209381-6-jolsa@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-08-22bpf: Add cookies support for uprobe_multi linkJiri Olsa1-1/+1
Adding support to specify cookies array for uprobe_multi link. The cookies array share indexes and length with other uprobe_multi arrays (offsets/ref_ctr_offsets). The cookies[i] value defines cookie for i-the uprobe and will be returned by bpf_get_attach_cookie helper when called from ebpf program hooked to that specific uprobe. Acked-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Yafang Shao <laoar.shao@gmail.com> Signed-off-by: Jiri Olsa <jolsa@kernel.org> Acked-by: Yonghong Song <yonghong.song@linux.dev> Link: https://lore.kernel.org/r/20230809083440.3209381-5-jolsa@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-08-22bpf: Add multi uprobe linkJiri Olsa1-3/+11
Adding new multi uprobe link that allows to attach bpf program to multiple uprobes. Uprobes to attach are specified via new link_create uprobe_multi union: struct { __aligned_u64 path; __aligned_u64 offsets; __aligned_u64 ref_ctr_offsets; __u32 cnt; __u32 flags; } uprobe_multi; Uprobes are defined for single binary specified in path and multiple calling sites specified in offsets array with optional reference counters specified in ref_ctr_offsets array. All specified arrays have length of 'cnt'. The 'flags' supports single bit for now that marks the uprobe as return probe. Acked-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Yafang Shao <laoar.shao@gmail.com> Signed-off-by: Jiri Olsa <jolsa@kernel.org> Acked-by: Yonghong Song <yonghong.song@linux.dev> Link: https://lore.kernel.org/r/20230809083440.3209381-4-jolsa@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-08-22bpf: Add attach_type checks under bpf_prog_attach_check_attach_typeJiri Olsa1-68/+52
Add extra attach_type checks from link_create under bpf_prog_attach_check_attach_type. Suggested-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Yafang Shao <laoar.shao@gmail.com> Signed-off-by: Jiri Olsa <jolsa@kernel.org> Acked-by: Yonghong Song <yonghong.song@linux.dev> Link: https://lore.kernel.org/r/20230809083440.3209381-3-jolsa@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-08-22bpf, cpumask: Clean up bpf_cpu_map_entry directly in cpu_map_freeHou Tao1-9/+8
After synchronous_rcu(), both the dettached XDP program and xdp_do_flush() are completed, and the only user of bpf_cpu_map_entry will be cpu_map_kthread_run(), so instead of calling __cpu_map_entry_replace() to stop kthread and cleanup entry after a RCU grace period, do these things directly. Signed-off-by: Hou Tao <houtao1@huawei.com> Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com> Link: https://lore.kernel.org/r/20230816045959.358059-3-houtao@huaweicloud.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-08-22bpf, cpumap: Use queue_rcu_work() to remove unnecessary rcu_barrier()Hou Tao1-69/+27
As for now __cpu_map_entry_replace() uses call_rcu() to wait for the inflight xdp program to exit the RCU read critical section, and then launch kworker cpu_map_kthread_stop() to call kthread_stop() to flush all pending xdp frames or skbs. But it is unnecessary to use rcu_barrier() in cpu_map_kthread_stop() to wait for the completion of __cpu_map_entry_free(), because rcu_barrier() will wait for all pending RCU callbacks and cpu_map_kthread_stop() only needs to wait for the completion of a specific __cpu_map_entry_free(). So use queue_rcu_work() to replace call_rcu(), schedule_work() and rcu_barrier(). queue_rcu_work() will queue a __cpu_map_entry_free() kworker after a RCU grace period. Because __cpu_map_entry_free() is running in a kworker context, so it is OK to do all of these freeing procedures include kthread_stop() in it. After the update, there is no need to do reference-counting for bpf_cpu_map_entry, because bpf_cpu_map_entry is freed directly in __cpu_map_entry_free(), so just remove it. Signed-off-by: Hou Tao <houtao1@huawei.com> Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com> Link: https://lore.kernel.org/r/20230816045959.358059-2-houtao@huaweicloud.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-08-16bpf: Fix uninitialized symbol in bpf_perf_link_fill_kprobe()Yafang Shao1-3/+2
The commit 1b715e1b0ec5 ("bpf: Support ->fill_link_info for perf_event") leads to the following Smatch static checker warning: kernel/bpf/syscall.c:3416 bpf_perf_link_fill_kprobe() error: uninitialized symbol 'type'. That can happens when uname is NULL. So fix it by verifying the uname when we really need to fill it. Fixes: 1b715e1b0ec5 ("bpf: Support ->fill_link_info for perf_event") Reported-by: Dan Carpenter <dan.carpenter@linaro.org> Signed-off-by: Yafang Shao <laoar.shao@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Yonghong Song <yonghong.song@linux.dev> Acked-by: Jiri Olsa <jolsa@kernel.org> Closes: https://lore.kernel.org/bpf/85697a7e-f897-4f74-8b43-82721bebc462@kili.mountain Link: https://lore.kernel.org/bpf/20230813141900.1268-2-laoar.shao@gmail.com
2023-08-15bpf: Support default .validate() and .update() behavior for struct_ops linksDavid Vernet1-6/+9
Currently, if a struct_ops map is loaded with BPF_F_LINK, it must also define the .validate() and .update() callbacks in its corresponding struct bpf_struct_ops in the kernel. Enabling struct_ops link is useful in its own right to ensure that the map is unloaded if an application crashes. For example, with sched_ext, we want to automatically unload the host-wide scheduler if the application crashes. We would likely never support updating elements of a sched_ext struct_ops map, so we'd have to implement these callbacks showing that they _can't_ support element updates just to benefit from the basic lifetime management of struct_ops links. Let's enable struct_ops maps to work with BPF_F_LINK even if they haven't defined these callbacks, by assuming that a struct_ops map element cannot be updated by default. Acked-by: Kui-Feng Lee <thinker.li@gmail.com> Signed-off-by: David Vernet <void@manifault.com> Link: https://lore.kernel.org/r/20230814185908.700553-2-void@manifault.com Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2023-08-09bpf: lru: Remove unused declaration bpf_lru_promote()Yue Haibing1-1/+0
Commit 3a08c2fd7634 ("bpf: LRU List") declared but never implemented this. Signed-off-by: Yue Haibing <yuehaibing@huawei.com> Link: https://lore.kernel.org/r/20230808145531.19692-1-yuehaibing@huawei.com Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2023-08-08bpf: Fix an incorrect verification success with movsx insnYonghong Song1-11/+20
syzbot reports a verifier bug which triggers a runtime panic. The test bpf program is: 0: (62) *(u32 *)(r10 -8) = 553656332 1: (bf) r1 = (s16)r10 2: (07) r1 += -8 3: (b7) r2 = 3 4: (bd) if r2 <= r1 goto pc+0 5: (85) call bpf_trace_printk#-138320 6: (b7) r0 = 0 7: (95) exit At insn 1, the current implementation keeps 'r1' as a frame pointer, which caused later bpf_trace_printk helper call crash since frame pointer address is not valid any more. Note that at insn 4, the 'pointer vs. scalar' comparison is allowed for privileged prog run. To fix the problem with above insn 1, the fix in the patch adopts similar pattern to existing 'R1 = (u32) R2' handling. For unprivileged prog run, verification will fail with 'R<num> sign-extension part of pointer'. For privileged prog run, the dst_reg 'r1' will be marked as an unknown scalar, so later 'bpf_trace_pointk' helper will complain since it expected certain pointers. Reported-by: syzbot+d61b595e9205573133b3@syzkaller.appspotmail.com Fixes: 8100928c8814 ("bpf: Support new sign-extension mov insns") Signed-off-by: Yonghong Song <yonghong.song@linux.dev> Acked-by: Eduard Zingerman <eddyz87@gmail.com> Link: https://lore.kernel.org/r/20230807175721.671696-1-yonghong.song@linux.dev Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2023-08-05bpf: change bpf_alu_sign_string and bpf_movsx_string to staticYang Yingliang1-2/+2
The bpf_alu_sign_string and bpf_movsx_string introduced in commit f835bb622299 ("bpf: Add kernel/bpftool asm support for new instructions") are only used in disasm.c now, change them to static. Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202308050615.wxAn1v2J-lkp@intel.com/ Acked-by: Yonghong Song <yonghong.song@linux.dev> Link: https://lore.kernel.org/r/20230803023128.3753323-1-yangyingliang@huawei.com Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2023-08-05bpf: fix bpf_dynptr_slice() to stop return an ERR_PTR.Kui-Feng Lee1-1/+1
Verify if the pointer obtained from bpf_xdp_pointer() is either an error or NULL before returning it. The function bpf_dynptr_slice() mistakenly returned an ERR_PTR. Instead of solely checking for NULL, it should also verify if the pointer returned by bpf_xdp_pointer() is an error or NULL. Reported-by: Dan Carpenter <dan.carpenter@linaro.org> Closes: https://lore.kernel.org/bpf/d1360219-85c3-4a03-9449-253ea905f9d1@moroto.mountain/ Fixes: 66e3a13e7c2c ("bpf: Add bpf_dynptr_slice and bpf_dynptr_slice_rdwr") Suggested-by: Alexei Starovoitov <alexei.starovoitov@gmail.com> Signed-off-by: Kui-Feng Lee <thinker.li@gmail.com> Acked-by: Yonghong Song <yonghong.song@linux.dev> Link: https://lore.kernel.org/r/20230803231206.1060485-1-thinker.li@gmail.com Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2023-08-04bpf: Fix mprog detachment for empty mprog entryDaniel Borkmann1-0/+2
syzbot reported an UBSAN array-index-out-of-bounds access in bpf_mprog_read() upon bpf_mprog_detach(). While it did not have a reproducer, I was able to manually reproduce through an empty mprog entry which just has miniq present. The latter is important given otherwise we get an ENOENT error as tcx detaches the whole mprog entry. The index 4294967295 was triggered via NULL dtuple.prog which then attempts to detach from the back. bpf_mprog_fetch() in this case did hit the idx == total and therefore tried to grab the entry at idx -1. Fix it by adding an explicit bpf_mprog_total() check in bpf_mprog_detach() and bail out early with ENOENT. Fixes: 053c8e1f235d ("bpf: Add generic attach/detach/query API for multi-progs") Reported-by: syzbot+0c06ba0f831fe07a8f27@syzkaller.appspotmail.com Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/r/20230804131112.11012-1-daniel@iogearbox.net Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
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