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2024-10-22bpf: Add MEM_WRITE attributeDaniel Borkmann1-3/+11
Add a MEM_WRITE attribute for BPF helper functions which can be used in bpf_func_proto to annotate an argument type in order to let the verifier know that the helper writes into the memory passed as an argument. In the past MEM_UNINIT has been (ab)used for this function, but the latter merely tells the verifier that the passed memory can be uninitialized. There have been bugs with overloading the latter but aside from that there are also cases where the passed memory is read + written which currently cannot be expressed, see also 4b3786a6c539 ("bpf: Zero former ARG_PTR_TO_{LONG,INT} args in case of error"). Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Link: https://lore.kernel.org/r/20241021152809.33343-1-daniel@iogearbox.net Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-09-24Merge tag 'bpf-next-6.12-struct-fd' of ↵Linus Torvalds1-1/+10
git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next Pull bpf 'struct fd' updates from Alexei Starovoitov: "This includes struct_fd BPF changes from Al and Andrii" * tag 'bpf-next-6.12-struct-fd' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: bpf: convert bpf_token_create() to CLASS(fd, ...) security,bpf: constify struct path in bpf_token_create() LSM hook bpf: more trivial fdget() conversions bpf: trivial conversions for fdget() bpf: switch maps to CLASS(fd, ...) bpf: factor out fetching bpf_map from FD and adding it to used_maps list bpf: switch fdget_raw() uses to CLASS(fd_raw, ...) bpf: convert __bpf_prog_get() to CLASS(fd, ...)
2024-09-13bpf: Fix helper writes to read-only mapsDaniel Borkmann1-2/+5
Lonial found an issue that despite user- and BPF-side frozen BPF map (like in case of .rodata), it was still possible to write into it from a BPF program side through specific helpers having ARG_PTR_TO_{LONG,INT} as arguments. In check_func_arg() when the argument is as mentioned, the meta->raw_mode is never set. Later, check_helper_mem_access(), under the case of PTR_TO_MAP_VALUE as register base type, it assumes BPF_READ for the subsequent call to check_map_access_type() and given the BPF map is read-only it succeeds. The helpers really need to be annotated as ARG_PTR_TO_{LONG,INT} | MEM_UNINIT when results are written into them as opposed to read out of them. The latter indicates that it's okay to pass a pointer to uninitialized memory as the memory is written to anyway. However, ARG_PTR_TO_{LONG,INT} is a special case of ARG_PTR_TO_FIXED_SIZE_MEM just with additional alignment requirement. So it is better to just get rid of the ARG_PTR_TO_{LONG,INT} special cases altogether and reuse the fixed size memory types. For this, add MEM_ALIGNED to additionally ensure alignment given these helpers write directly into the args via *<ptr> = val. The .arg*_size has been initialized reflecting the actual sizeof(*<ptr>). MEM_ALIGNED can only be used in combination with MEM_FIXED_SIZE annotated argument types, since in !MEM_FIXED_SIZE cases the verifier does not know the buffer size a priori and therefore cannot blindly write *<ptr> = val. Fixes: 57c3bb725a3d ("bpf: Introduce ARG_PTR_TO_{INT,LONG} arg types") Reported-by: Lonial Con <kongln9170@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Shung-Hsi Yu <shung-hsi.yu@suse.com> Link: https://lore.kernel.org/r/20240913191754.13290-3-daniel@iogearbox.net Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-09-11bpf: wire up sleepable bpf_get_stack() and bpf_get_task_stack() helpersAndrii Nakryiko1-0/+2
Add sleepable implementations of bpf_get_stack() and bpf_get_task_stack() helpers and allow them to be used from sleepable BPF program (e.g., sleepable uprobes). Note, the stack trace IPs capturing itself is not sleepable (that would need to be a separate project), only build ID fetching is sleepable and thus more reliable, as it will wait for data to be paged in, if necessary. For that we make use of sleepable build_id_parse() implementation. Now that build ID related internals in kernel/bpf/stackmap.c can be used both in sleepable and non-sleepable contexts, we need to add additional rcu_read_lock()/rcu_read_unlock() protection around fetching perf_callchain_entry, but with the refactoring in previous commit it's now pretty straightforward. We make sure to do rcu_read_unlock (in sleepable mode only) right before stack_map_get_build_id_offset() call which can sleep. By that time we don't have any more use of perf_callchain_entry. Note, bpf_get_task_stack() will fail for user mode if task != current. And for kernel mode build ID are irrelevant. So in that sense adding sleepable bpf_get_task_stack() implementation is a no-op. It feel right to wire this up for symmetry and completeness, but I'm open to just dropping it until we support `user && crosstask` condition. Reviewed-by: Eduard Zingerman <eddyz87@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20240829174232.3133883-10-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-08-29bpf: Add gen_epilogue to bpf_verifier_opsMartin KaFai Lau1-0/+2
This patch adds a .gen_epilogue to the bpf_verifier_ops. It is similar to the existing .gen_prologue. Instead of allowing a subsystem to run code at the beginning of a bpf prog, it allows the subsystem to run code just before the bpf prog exit. One of the use case is to allow the upcoming bpf qdisc to ensure that the skb->dev is the same as the qdisc->dev_queue->dev. The bpf qdisc struct_ops implementation could either fix it up or drop the skb. Another use case could be in bpf_tcp_ca.c to enforce snd_cwnd has sane value (e.g. non zero). The epilogue can do the useful thing (like checking skb->dev) if it can access the bpf prog's ctx. Unlike prologue, r1 may not hold the ctx pointer. This patch saves the r1 in the stack if the .gen_epilogue has returned some instructions in the "epilogue_buf". The existing .gen_prologue is done in convert_ctx_accesses(). The new .gen_epilogue is done in the convert_ctx_accesses() also. When it sees the (BPF_JMP | BPF_EXIT) instruction, it will be patched with the earlier generated "epilogue_buf". The epilogue patching is only done for the main prog. Only one epilogue will be patched to the main program. When the bpf prog has multiple BPF_EXIT instructions, a BPF_JA is used to goto the earlier patched epilogue. Majority of the archs support (BPF_JMP32 | BPF_JA): x86, arm, s390, risv64, loongarch, powerpc and arc. This patch keeps it simple and always use (BPF_JMP32 | BPF_JA). A new macro BPF_JMP32_A is added to generate the (BPF_JMP32 | BPF_JA) insn. Acked-by: Eduard Zingerman <eddyz87@gmail.com> Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> Link: https://lore.kernel.org/r/20240829210833.388152-4-martin.lau@linux.dev Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-08-23bpf: Rename ARG_PTR_TO_KPTR -> ARG_KPTR_XCHG_DESTDave Marchevsky1-1/+1
ARG_PTR_TO_KPTR is currently only used by the bpf_kptr_xchg helper. Although it limits reg types for that helper's first arg to PTR_TO_MAP_VALUE, any arbitrary mapval won't do: further custom verification logic ensures that the mapval reg being xchgd-into is pointing to a kptr field. If this is not the case, it's not safe to xchg into that reg's pointee. Let's rename the bpf_arg_type to more accurately describe the fairly specific expectations that this arg type encodes. This is a nonfunctional change. Acked-by: Martin KaFai Lau <martin.lau@kernel.org> Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com> Signed-off-by: Amery Hung <amery.hung@bytedance.com> Link: https://lore.kernel.org/r/20240813212424.2871455-4-amery.hung@bytedance.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-08-22bpf: rename nocsr -> bpf_fastcall in verifierEduard Zingerman1-3/+3
Attribute used by LLVM implementation of the feature had been changed from no_caller_saved_registers to bpf_fastcall (see [1]). This commit replaces references to nocsr by references to bpf_fastcall to keep LLVM and Kernel parts in sync. [1] https://github.com/llvm/llvm-project/pull/105417 Acked-by: Yonghong Song <yonghong.song@linux.dev> Signed-off-by: Eduard Zingerman <eddyz87@gmail.com> Link: https://lore.kernel.org/r/20240822084112.3257995-2-eddyz87@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-08-19bpf: Allow bpf_current_task_under_cgroup() with BPF_CGROUP_*Matteo Croce1-0/+1
The helper bpf_current_task_under_cgroup() currently is only allowed for tracing programs, allow its usage also in the BPF_CGROUP_* program types. Move the code from kernel/trace/bpf_trace.c to kernel/bpf/helpers.c, so it compiles also without CONFIG_BPF_EVENTS. This will be used in systemd-networkd to monitor the sysctl writes, and filter it's own writes from others: https://github.com/systemd/systemd/pull/32212 Signed-off-by: Matteo Croce <teknoraver@meta.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20240819162805.78235-3-technoboy85@gmail.com
2024-08-13bpf: switch maps to CLASS(fd, ...)Al Viro1-1/+10
Calling conventions for __bpf_map_get() would be more convenient if it left fpdut() on failure to callers. Makes for simpler logics in the callers. Among other things, the proof of memory safety no longer has to rely upon file->private_data never being ERR_PTR(...) for bpffs files. Original calling conventions made it impossible for the caller to tell whether __bpf_map_get() has returned ERR_PTR(-EINVAL) because it has found the file not be a bpf map one (in which case it would've done fdput()) or because it found that ERR_PTR(-EINVAL) in file->private_data of a bpf map file (in which case fdput() would _not_ have been done). Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Reviewed-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
2024-07-29bpf: no_caller_saved_registers attribute for helper callsEduard Zingerman1-0/+6
GCC and LLVM define a no_caller_saved_registers function attribute. This attribute means that function scratches only some of the caller saved registers defined by ABI. For BPF the set of such registers could be defined as follows: - R0 is scratched only if function is non-void; - R1-R5 are scratched only if corresponding parameter type is defined in the function prototype. This commit introduces flag bpf_func_prot->allow_nocsr. If this flag is set for some helper function, verifier assumes that it follows no_caller_saved_registers calling convention. The contract between kernel and clang allows to simultaneously use such functions and maintain backwards compatibility with old kernels that don't understand no_caller_saved_registers calls (nocsr for short): - clang generates a simple pattern for nocsr calls, e.g.: r1 = 1; r2 = 2; *(u64 *)(r10 - 8) = r1; *(u64 *)(r10 - 16) = r2; call %[to_be_inlined] r2 = *(u64 *)(r10 - 16); r1 = *(u64 *)(r10 - 8); r0 = r1; r0 += r2; exit; - kernel removes unnecessary spills and fills, if called function is inlined by verifier or current JIT (with assumption that patch inserted by verifier or JIT honors nocsr contract, e.g. does not scratch r3-r5 for the example above), e.g. the code above would be transformed to: r1 = 1; r2 = 2; call %[to_be_inlined] r0 = r1; r0 += r2; exit; Technically, the transformation is split into the following phases: - function mark_nocsr_patterns(), called from bpf_check() searches and marks potential patterns in instruction auxiliary data; - upon stack read or write access, function check_nocsr_stack_contract() is used to verify if stack offsets, presumably reserved for nocsr patterns, are used only from those patterns; - function remove_nocsr_spills_fills(), called from bpf_check(), applies the rewrite for valid patterns. See comment in mark_nocsr_pattern_for_call() for more details. Suggested-by: Alexei Starovoitov <alexei.starovoitov@gmail.com> Signed-off-by: Eduard Zingerman <eddyz87@gmail.com> Link: https://lore.kernel.org/r/20240722233844.1406874-3-eddyz87@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
2024-07-29bpf: Fail verification for sign-extension of packet data/data_end/data_metaYonghong Song1-0/+1
syzbot reported a kernel crash due to commit 1f1e864b6555 ("bpf: Handle sign-extenstin ctx member accesses"). The reason is due to sign-extension of 32-bit load for packet data/data_end/data_meta uapi field. The original code looks like: r2 = *(s32 *)(r1 + 76) /* load __sk_buff->data */ r3 = *(u32 *)(r1 + 80) /* load __sk_buff->data_end */ r0 = r2 r0 += 8 if r3 > r0 goto +1 ... Note that __sk_buff->data load has 32-bit sign extension. After verification and convert_ctx_accesses(), the final asm code looks like: r2 = *(u64 *)(r1 +208) r2 = (s32)r2 r3 = *(u64 *)(r1 +80) r0 = r2 r0 += 8 if r3 > r0 goto pc+1 ... Note that 'r2 = (s32)r2' may make the kernel __sk_buff->data address invalid which may cause runtime failure. Currently, in C code, typically we have void *data = (void *)(long)skb->data; void *data_end = (void *)(long)skb->data_end; ... and it will generate r2 = *(u64 *)(r1 +208) r3 = *(u64 *)(r1 +80) r0 = r2 r0 += 8 if r3 > r0 goto pc+1 If we allow sign-extension, void *data = (void *)(long)(int)skb->data; void *data_end = (void *)(long)skb->data_end; ... the generated code looks like r2 = *(u64 *)(r1 +208) r2 <<= 32 r2 s>>= 32 r3 = *(u64 *)(r1 +80) r0 = r2 r0 += 8 if r3 > r0 goto pc+1 and this will cause verification failure since "r2 <<= 32" is not allowed as "r2" is a packet pointer. To fix this issue for case r2 = *(s32 *)(r1 + 76) /* load __sk_buff->data */ this patch added additional checking in is_valid_access() callback function for packet data/data_end/data_meta access. If those accesses are with sign-extenstion, the verification will fail. [1] https://lore.kernel.org/bpf/000000000000c90eee061d236d37@google.com/ Reported-by: syzbot+ad9ec60c8eaf69e6f99c@syzkaller.appspotmail.com Fixes: 1f1e864b6555 ("bpf: Handle sign-extenstin ctx member accesses") Acked-by: Eduard Zingerman <eddyz87@gmail.com> Signed-off-by: Yonghong Song <yonghong.song@linux.dev> Link: https://lore.kernel.org/r/20240723153439.2429035-1-yonghong.song@linux.dev Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
2024-07-29bpf: Prevent tail call between progs attached to different hooksXu Kuohai1-0/+1
bpf progs can be attached to kernel functions, and the attached functions can take different parameters or return different return values. If prog attached to one kernel function tail calls prog attached to another kernel function, the ctx access or return value verification could be bypassed. For example, if prog1 is attached to func1 which takes only 1 parameter and prog2 is attached to func2 which takes two parameters. Since verifier assumes the bpf ctx passed to prog2 is constructed based on func2's prototype, verifier allows prog2 to access the second parameter from the bpf ctx passed to it. The problem is that verifier does not prevent prog1 from passing its bpf ctx to prog2 via tail call. In this case, the bpf ctx passed to prog2 is constructed from func1 instead of func2, that is, the assumption for ctx access verification is bypassed. Another example, if BPF LSM prog1 is attached to hook file_alloc_security, and BPF LSM prog2 is attached to hook bpf_lsm_audit_rule_known. Verifier knows the return value rules for these two hooks, e.g. it is legal for bpf_lsm_audit_rule_known to return positive number 1, and it is illegal for file_alloc_security to return positive number. So verifier allows prog2 to return positive number 1, but does not allow prog1 to return positive number. The problem is that verifier does not prevent prog1 from calling prog2 via tail call. In this case, prog2's return value 1 will be used as the return value for prog1's hook file_alloc_security. That is, the return value rule is bypassed. This patch adds restriction for tail call to prevent such bypasses. Signed-off-by: Xu Kuohai <xukuohai@huawei.com> Link: https://lore.kernel.org/r/20240719110059.797546-4-xukuohai@huaweicloud.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
2024-07-29bpf, lsm: Add check for BPF LSM return valueXu Kuohai1-0/+1
A bpf prog returning a positive number attached to file_alloc_security hook makes kernel panic. This happens because file system can not filter out the positive number returned by the LSM prog using IS_ERR, and misinterprets this positive number as a file pointer. Given that hook file_alloc_security never returned positive number before the introduction of BPF LSM, and other BPF LSM hooks may encounter similar issues, this patch adds LSM return value check in verifier, to ensure no unexpected value is returned. Fixes: 520b7aa00d8c ("bpf: lsm: Initialize the BPF LSM hooks") Reported-by: Xin Liu <liuxin350@huawei.com> Signed-off-by: Xu Kuohai <xukuohai@huawei.com> Acked-by: Eduard Zingerman <eddyz87@gmail.com> Link: https://lore.kernel.org/r/20240719110059.797546-3-xukuohai@huaweicloud.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
2024-07-29bpf: Check unsupported ops from the bpf_struct_ops's cfi_stubsMartin KaFai Lau1-0/+5
The bpf_tcp_ca struct_ops currently uses a "u32 unsupported_ops[]" array to track which ops is not supported. After cfi_stubs had been added, the function pointer in cfi_stubs is also NULL for the unsupported ops. Thus, the "u32 unsupported_ops[]" becomes redundant. This observation was originally brought up in the bpf/cfi discussion: https://lore.kernel.org/bpf/CAADnVQJoEkdjyCEJRPASjBw1QGsKYrF33QdMGc1RZa9b88bAEA@mail.gmail.com/ The recent bpf qdisc patch (https://lore.kernel.org/bpf/20240714175130.4051012-6-amery.hung@bytedance.com/) also needs to specify quite many unsupported ops. It is a good time to clean it up. This patch removes the need of "u32 unsupported_ops[]" and tests for null-ness in the cfi_stubs instead. Testing the cfi_stubs is done in a new function bpf_struct_ops_supported(). The verifier will call bpf_struct_ops_supported() when loading the struct_ops program. The ".check_member" is removed from the bpf_tcp_ca in this patch. ".check_member" could still be useful for other subsytems to enforce other restrictions (e.g. sched_ext checks for prog->sleepable). To keep the same error return, ENOTSUPP is used. Cc: Amery Hung <ameryhung@gmail.com> Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> Link: https://lore.kernel.org/r/20240722183049.2254692-2-martin.lau@linux.dev Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
2024-07-21Merge tag 'mm-stable-2024-07-21-14-50' of ↵Linus Torvalds1-2/+6
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: - In the series "mm: Avoid possible overflows in dirty throttling" Jan Kara addresses a couple of issues in the writeback throttling code. These fixes are also targetted at -stable kernels. - Ryusuke Konishi's series "nilfs2: fix potential issues related to reserved inodes" does that. This should actually be in the mm-nonmm-stable tree, along with the many other nilfs2 patches. My bad. - More folio conversions from Kefeng Wang in the series "mm: convert to folio_alloc_mpol()" - Kemeng Shi has sent some cleanups to the writeback code in the series "Add helper functions to remove repeated code and improve readability of cgroup writeback" - Kairui Song has made the swap code a little smaller and a little faster in the series "mm/swap: clean up and optimize swap cache index". - In the series "mm/memory: cleanly support zeropage in vm_insert_page*(), vm_map_pages*() and vmf_insert_mixed()" David Hildenbrand has reworked the rather sketchy handling of the use of the zeropage in MAP_SHARED mappings. I don't see any runtime effects here - more a cleanup/understandability/maintainablity thing. - Dev Jain has improved selftests/mm/va_high_addr_switch.c's handling of higher addresses, for aarch64. The (poorly named) series is "Restructure va_high_addr_switch". - The core TLB handling code gets some cleanups and possible slight optimizations in Bang Li's series "Add update_mmu_tlb_range() to simplify code". - Jane Chu has improved the handling of our fake-an-unrecoverable-memory-error testing feature MADV_HWPOISON in the series "Enhance soft hwpoison handling and injection". - Jeff Johnson has sent a billion patches everywhere to add MODULE_DESCRIPTION() to everything. Some landed in this pull. - In the series "mm: cleanup MIGRATE_SYNC_NO_COPY mode", Kefeng Wang has simplified migration's use of hardware-offload memory copying. - Yosry Ahmed performs more folio API conversions in his series "mm: zswap: trivial folio conversions". - In the series "large folios swap-in: handle refault cases first", Chuanhua Han inches us forward in the handling of large pages in the swap code. This is a cleanup and optimization, working toward the end objective of full support of large folio swapin/out. - In the series "mm,swap: cleanup VMA based swap readahead window calculation", Huang Ying has contributed some cleanups and a possible fixlet to his VMA based swap readahead code. - In the series "add mTHP support for anonymous shmem" Baolin Wang has taught anonymous shmem mappings to use multisize THP. By default this is a no-op - users must opt in vis sysfs controls. Dramatic improvements in pagefault latency are realized. - David Hildenbrand has some cleanups to our remaining use of page_mapcount() in the series "fs/proc: move page_mapcount() to fs/proc/internal.h". - David also has some highmem accounting cleanups in the series "mm/highmem: don't track highmem pages manually". - Build-time fixes and cleanups from John Hubbard in the series "cleanups, fixes, and progress towards avoiding "make headers"". - Cleanups and consolidation of the core pagemap handling from Barry Song in the series "mm: introduce pmd|pte_needs_soft_dirty_wp helpers and utilize them". - Lance Yang's series "Reclaim lazyfree THP without splitting" has reduced the latency of the reclaim of pmd-mapped THPs under fairly common circumstances. A 10x speedup is seen in a microbenchmark. It does this by punting to aother CPU but I guess that's a win unless all CPUs are pegged. - hugetlb_cgroup cleanups from Xiu Jianfeng in the series "mm/hugetlb_cgroup: rework on cftypes". - Miaohe Lin's series "Some cleanups for memory-failure" does just that thing. - Someone other than SeongJae has developed a DAMON feature in Honggyu Kim's series "DAMON based tiered memory management for CXL memory". This adds DAMON features which may be used to help determine the efficiency of our placement of CXL/PCIe attached DRAM. - DAMON user API centralization and simplificatio work in SeongJae Park's series "mm/damon: introduce DAMON parameters online commit function". - In the series "mm: page_type, zsmalloc and page_mapcount_reset()" David Hildenbrand does some maintenance work on zsmalloc - partially modernizing its use of pageframe fields. - Kefeng Wang provides more folio conversions in the series "mm: remove page_maybe_dma_pinned() and page_mkclean()". - More cleanup from David Hildenbrand, this time in the series "mm/memory_hotplug: use PageOffline() instead of PageReserved() for !ZONE_DEVICE". It "enlightens memory hotplug more about PageOffline() pages" and permits the removal of some virtio-mem hacks. - Barry Song's series "mm: clarify folio_add_new_anon_rmap() and __folio_add_anon_rmap()" is a cleanup to the anon folio handling in preparation for mTHP (multisize THP) swapin. - Kefeng Wang's series "mm: improve clear and copy user folio" implements more folio conversions, this time in the area of large folio userspace copying. - The series "Docs/mm/damon/maintaier-profile: document a mailing tool and community meetup series" tells people how to get better involved with other DAMON developers. From SeongJae Park. - A large series ("kmsan: Enable on s390") from Ilya Leoshkevich does that. - David Hildenbrand sends along more cleanups, this time against the migration code. The series is "mm/migrate: move NUMA hinting fault folio isolation + checks under PTL". - Jan Kara has found quite a lot of strangenesses and minor errors in the readahead code. He addresses this in the series "mm: Fix various readahead quirks". - SeongJae Park's series "selftests/damon: test DAMOS tried regions and {min,max}_nr_regions" adds features and addresses errors in DAMON's self testing code. - Gavin Shan has found a userspace-triggerable WARN in the pagecache code. The series "mm/filemap: Limit page cache size to that supported by xarray" addresses this. The series is marked cc:stable. - Chengming Zhou's series "mm/ksm: cmp_and_merge_page() optimizations and cleanup" cleans up and slightly optimizes KSM. - Roman Gushchin has separated the memcg-v1 and memcg-v2 code - lots of code motion. The series (which also makes the memcg-v1 code Kconfigurable) are "mm: memcg: separate legacy cgroup v1 code and put under config option" and "mm: memcg: put cgroup v1-specific memcg data under CONFIG_MEMCG_V1" - Dan Schatzberg's series "Add swappiness argument to memory.reclaim" adds an additional feature to this cgroup-v2 control file. - The series "Userspace controls soft-offline pages" from Jiaqi Yan permits userspace to stop the kernel's automatic treatment of excessive correctable memory errors. In order to permit userspace to monitor and handle this situation. - Kefeng Wang's series "mm: migrate: support poison recover from migrate folio" teaches the kernel to appropriately handle migration from poisoned source folios rather than simply panicing. - SeongJae Park's series "Docs/damon: minor fixups and improvements" does those things. - In the series "mm/zsmalloc: change back to per-size_class lock" Chengming Zhou improves zsmalloc's scalability and memory utilization. - Vivek Kasireddy's series "mm/gup: Introduce memfd_pin_folios() for pinning memfd folios" makes the GUP code use FOLL_PIN rather than bare refcount increments. So these paes can first be moved aside if they reside in the movable zone or a CMA block. - Andrii Nakryiko has added a binary ioctl()-based API to /proc/pid/maps for much faster reading of vma information. The series is "query VMAs from /proc/<pid>/maps". - In the series "mm: introduce per-order mTHP split counters" Lance Yang improves the kernel's presentation of developer information related to multisize THP splitting. - Michael Ellerman has developed the series "Reimplement huge pages without hugepd on powerpc (8xx, e500, book3s/64)". This permits userspace to use all available huge page sizes. - In the series "revert unconditional slab and page allocator fault injection calls" Vlastimil Babka removes a performance-affecting and not very useful feature from slab fault injection. * tag 'mm-stable-2024-07-21-14-50' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (411 commits) mm/mglru: fix ineffective protection calculation mm/zswap: fix a white space issue mm/hugetlb: fix kernel NULL pointer dereference when migrating hugetlb folio mm/hugetlb: fix possible recursive locking detected warning mm/gup: clear the LRU flag of a page before adding to LRU batch mm/numa_balancing: teach mpol_to_str about the balancing mode mm: memcg1: convert charge move flags to unsigned long long alloc_tag: fix page_ext_get/page_ext_put sequence during page splitting lib: reuse page_ext_data() to obtain codetag_ref lib: add missing newline character in the warning message mm/mglru: fix overshooting shrinker memory mm/mglru: fix div-by-zero in vmpressure_calc_level() mm/kmemleak: replace strncpy() with strscpy() mm, page_alloc: put should_fail_alloc_page() back behing CONFIG_FAIL_PAGE_ALLOC mm, slab: put should_failslab() back behind CONFIG_SHOULD_FAILSLAB mm: ignore data-race in __swap_writepage hugetlbfs: ensure generic_hugetlb_get_unmapped_area() returns higher address than mmap_min_addr mm: shmem: rename mTHP shmem counters mm: swap_state: use folio_alloc_mpol() in __read_swap_cache_async() mm/migrate: putback split folios when numa hint migration fails ...
2024-07-12mm: add comments for allocation helpers explaining why they are macrosSuren Baghdasaryan1-0/+4
A number of allocation helper functions were converted into macros to account them at the call sites. Add a comment for each converted allocation helper explaining why it has to be a macro and why we typecast the return value wherever required. The patch also moves acpi_os_acquire_object() closer to other allocation helpers to group them together under the same comment. The patch has no functional changes. Link: https://lkml.kernel.org/r/20240703174225.3891393-1-surenb@google.com Fixes: 2c321f3f70bc ("mm: change inlined allocation helpers to account at the call site") Signed-off-by: Suren Baghdasaryan <surenb@google.com> Suggested-by: Andrew Morton <akpm@linux-foundation.org> Cc: Christian König <christian.koenig@amd.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Jan Kara <jack@suse.cz> Cc: Kent Overstreet <kent.overstreet@linux.dev> Cc: Thorsten Blum <thorsten.blum@toblux.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-10mm: remove CONFIG_MEMCG_KMEMJohannes Weiner1-2/+2
CONFIG_MEMCG_KMEM used to be a user-visible option for whether slab tracking is enabled. It has been default-enabled and equivalent to CONFIG_MEMCG for almost a decade. We've only grown more kernel memory accounting sites since, and there is no imaginable cgroup usecase going forward that wants to track user pages but not the multitude of user-drivable kernel allocations. Link: https://lkml.kernel.org/r/20240701153148.452230-1-hannes@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Roman Gushchin <roman.gushchin@linux.dev> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Shakeel Butt <shakeel.butt@linux.dev> Acked-by: David Hildenbrand <david@redhat.com> Cc: Muchun Song <muchun.song@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-09Merge tag 'for-netdev' of ↵Paolo Abeni1-6/+5
https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next Daniel Borkmann says: ==================== pull-request: bpf-next 2024-07-08 The following pull-request contains BPF updates for your *net-next* tree. We've added 102 non-merge commits during the last 28 day(s) which contain a total of 127 files changed, 4606 insertions(+), 980 deletions(-). The main changes are: 1) Support resilient split BTF which cuts down on duplication and makes BTF as compact as possible wrt BTF from modules, from Alan Maguire & Eduard Zingerman. 2) Add support for dumping kfunc prototypes from BTF which enables both detecting as well as dumping compilable prototypes for kfuncs, from Daniel Xu. 3) Batch of s390x BPF JIT improvements to add support for BPF arena and to implement support for BPF exceptions, from Ilya Leoshkevich. 4) Batch of riscv64 BPF JIT improvements in particular to add 12-argument support for BPF trampolines and to utilize bpf_prog_pack for the latter, from Pu Lehui. 5) Extend BPF test infrastructure to add a CHECKSUM_COMPLETE validation option for skbs and add coverage along with it, from Vadim Fedorenko. 6) Inline bpf_get_current_task/_btf() helpers in the arm64 BPF JIT which gives a small 1% performance improvement in micro-benchmarks, from Puranjay Mohan. 7) Extend the BPF verifier to track the delta between linked registers in order to better deal with recent LLVM code optimizations, from Alexei Starovoitov. 8) Fix bpf_wq_set_callback_impl() kfunc signature where the third argument should have been a pointer to the map value, from Benjamin Tissoires. 9) Extend BPF selftests to add regular expression support for test output matching and adjust some of the selftest when compiled under gcc, from Cupertino Miranda. 10) Simplify task_file_seq_get_next() and remove an unnecessary loop which always iterates exactly once anyway, from Dan Carpenter. 11) Add the capability to offload the netfilter flowtable in XDP layer through kfuncs, from Florian Westphal & Lorenzo Bianconi. 12) Various cleanups in networking helpers in BPF selftests to shave off a few lines of open-coded functions on client/server handling, from Geliang Tang. 13) Properly propagate prog->aux->tail_call_reachable out of BPF verifier, so that x86 JIT does not need to implement detection, from Leon Hwang. 14) Fix BPF verifier to add a missing check_func_arg_reg_off() to prevent an out-of-bounds memory access for dynpointers, from Matt Bobrowski. 15) Fix bpf_session_cookie() kfunc to return __u64 instead of long pointer as it might lead to problems on 32-bit archs, from Jiri Olsa. 16) Enhance traffic validation and dynamic batch size support in xsk selftests, from Tushar Vyavahare. bpf-next-for-netdev * tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (102 commits) selftests/bpf: DENYLIST.aarch64: Remove fexit_sleep selftests/bpf: amend for wrong bpf_wq_set_callback_impl signature bpf: helpers: fix bpf_wq_set_callback_impl signature libbpf: Add NULL checks to bpf_object__{prev_map,next_map} selftests/bpf: Remove exceptions tests from DENYLIST.s390x s390/bpf: Implement exceptions s390/bpf: Change seen_reg to a mask bpf: Remove unnecessary loop in task_file_seq_get_next() riscv, bpf: Optimize stack usage of trampoline bpf, devmap: Add .map_alloc_check selftests/bpf: Remove arena tests from DENYLIST.s390x selftests/bpf: Add UAF tests for arena atomics selftests/bpf: Introduce __arena_global s390/bpf: Support arena atomics s390/bpf: Enable arena s390/bpf: Support address space cast instruction s390/bpf: Support BPF_PROBE_MEM32 s390/bpf: Land on the next JITed instruction after exception s390/bpf: Introduce pre- and post- probe functions s390/bpf: Get rid of get_probe_mem_regno() ... ==================== Link: https://patch.msgid.link/20240708221438.10974-1-daniel@iogearbox.net Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-07-02net: Optimize xdp_do_flush() with bpf_net_context infos.Sebastian Andrzej Siewior1-6/+4
Every NIC driver utilizing XDP should invoke xdp_do_flush() after processing all packages. With the introduction of the bpf_net_context logic the flush lists (for dev, CPU-map and xsk) are lazy initialized only if used. However xdp_do_flush() tries to flush all three of them so all three lists are always initialized and the likely empty lists are "iterated". Without the usage of XDP but with CONFIG_DEBUG_NET the lists are also initialized due to xdp_do_check_flushed(). Jakub suggest to utilize the hints in bpf_net_context and avoid invoking the flush function. This will also avoiding initializing the lists which are otherwise unused. Introduce bpf_net_ctx_get_all_used_flush_lists() to return the individual list if not-empty. Use the logic in xdp_do_flush() and xdp_do_check_flushed(). Remove the not needed .*_check_flush(). Suggested-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Reviewed-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-06-20bpf: remove unused parameter in __bpf_free_used_btfsRafael Passos1-2/+1
Fixes a compiler warning. The __bpf_free_used_btfs function was taking an extra unused struct bpf_prog_aux *aux param Signed-off-by: Rafael Passos <rafael@rcpassos.me> Link: https://lore.kernel.org/r/20240615022641.210320-3-rafael@rcpassos.me Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-06-12bpf: treewide: Align kfunc signatures to prog point-of-viewDaniel Xu1-4/+4
Previously, kfunc declarations in bpf_kfuncs.h (and others) used "user facing" types for kfuncs prototypes while the actual kfunc definitions used "kernel facing" types. More specifically: bpf_dynptr vs bpf_dynptr_kern, __sk_buff vs sk_buff, and xdp_md vs xdp_buff. It wasn't an issue before, as the verifier allows aliased types. However, since we are now generating kfunc prototypes in vmlinux.h (in addition to keeping bpf_kfuncs.h around), this conflict creates compilation errors. Fix this conflict by using "user facing" types in kfunc definitions. This results in more casts, but otherwise has no additional runtime cost. Note, similar to 5b268d1ebcdc ("bpf: Have bpf_rdonly_cast() take a const pointer"), we also make kfuncs take const arguments where appropriate in order to make the kfunc more permissive. Signed-off-by: Daniel Xu <dxu@dxuuu.xyz> Link: https://lore.kernel.org/r/b58346a63a0e66bc9b7504da751b526b0b189a67.1718207789.git.dxu@dxuuu.xyz Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-05-30bpf: export bpf_link_inc_not_zero.Kui-Feng Lee1-0/+6
bpf_link_inc_not_zero() will be used by kernel modules. We will use it in bpf_testmod.c later. Signed-off-by: Kui-Feng Lee <thinker.li@gmail.com> Link: https://lore.kernel.org/r/20240530065946.979330-5-thinker.li@gmail.com Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2024-05-30bpf: support epoll from bpf struct_ops links.Kui-Feng Lee1-0/+1
Add epoll support to bpf struct_ops links to trigger EPOLLHUP event upon detachment. This patch implements the "poll" of the "struct file_operations" for BPF links and introduces a new "poll" operator in the "struct bpf_link_ops". By implementing "poll" of "struct bpf_link_ops" for the links of struct_ops, the file descriptor of a struct_ops link can be added to an epoll file descriptor to receive EPOLLHUP events. Signed-off-by: Kui-Feng Lee <thinker.li@gmail.com> Link: https://lore.kernel.org/r/20240530065946.979330-4-thinker.li@gmail.com Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2024-05-30bpf: pass bpf_struct_ops_link to callbacks in bpf_struct_ops.Kui-Feng Lee1-3/+3
Pass an additional pointer of bpf_struct_ops_link to callback function reg, unreg, and update provided by subsystems defined in bpf_struct_ops. A bpf_struct_ops_map can be registered for multiple links. Passing a pointer of bpf_struct_ops_link helps subsystems to distinguish them. This pointer will be used in the later patches to let the subsystem initiate a detachment on a link that was registered to it previously. Signed-off-by: Kui-Feng Lee <thinker.li@gmail.com> Link: https://lore.kernel.org/r/20240530065946.979330-2-thinker.li@gmail.com Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2024-05-19Merge tag 'mm-stable-2024-05-17-19-19' of ↵Linus Torvalds1-25/+8
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull mm updates from Andrew Morton: "The usual shower of singleton fixes and minor series all over MM, documented (hopefully adequately) in the respective changelogs. Notable series include: - Lucas Stach has provided some page-mapping cleanup/consolidation/ maintainability work in the series "mm/treewide: Remove pXd_huge() API". - In the series "Allow migrate on protnone reference with MPOL_PREFERRED_MANY policy", Donet Tom has optimized mempolicy's MPOL_PREFERRED_MANY mode, yielding almost doubled performance in one test. - In their series "Memory allocation profiling" Kent Overstreet and Suren Baghdasaryan have contributed a means of determining (via /proc/allocinfo) whereabouts in the kernel memory is being allocated: number of calls and amount of memory. - Matthew Wilcox has provided the series "Various significant MM patches" which does a number of rather unrelated things, but in largely similar code sites. - In his series "mm: page_alloc: freelist migratetype hygiene" Johannes Weiner has fixed the page allocator's handling of migratetype requests, with resulting improvements in compaction efficiency. - In the series "make the hugetlb migration strategy consistent" Baolin Wang has fixed a hugetlb migration issue, which should improve hugetlb allocation reliability. - Liu Shixin has hit an I/O meltdown caused by readahead in a memory-tight memcg. Addressed in the series "Fix I/O high when memory almost met memcg limit". - In the series "mm/filemap: optimize folio adding and splitting" Kairui Song has optimized pagecache insertion, yielding ~10% performance improvement in one test. - Baoquan He has cleaned up and consolidated the early zone initialization code in the series "mm/mm_init.c: refactor free_area_init_core()". - Baoquan has also redone some MM initializatio code in the series "mm/init: minor clean up and improvement". - MM helper cleanups from Christoph Hellwig in his series "remove follow_pfn". - More cleanups from Matthew Wilcox in the series "Various page->flags cleanups". - Vlastimil Babka has contributed maintainability improvements in the series "memcg_kmem hooks refactoring". - More folio conversions and cleanups in Matthew Wilcox's series: "Convert huge_zero_page to huge_zero_folio" "khugepaged folio conversions" "Remove page_idle and page_young wrappers" "Use folio APIs in procfs" "Clean up __folio_put()" "Some cleanups for memory-failure" "Remove page_mapping()" "More folio compat code removal" - David Hildenbrand chipped in with "fs/proc/task_mmu: convert hugetlb functions to work on folis". - Code consolidation and cleanup work related to GUP's handling of hugetlbs in Peter Xu's series "mm/gup: Unify hugetlb, part 2". - Rick Edgecombe has developed some fixes to stack guard gaps in the series "Cover a guard gap corner case". - Jinjiang Tu has fixed KSM's behaviour after a fork+exec in the series "mm/ksm: fix ksm exec support for prctl". - Baolin Wang has implemented NUMA balancing for multi-size THPs. This is a simple first-cut implementation for now. The series is "support multi-size THP numa balancing". - Cleanups to vma handling helper functions from Matthew Wilcox in the series "Unify vma_address and vma_pgoff_address". - Some selftests maintenance work from Dev Jain in the series "selftests/mm: mremap_test: Optimizations and style fixes". - Improvements to the swapping of multi-size THPs from Ryan Roberts in the series "Swap-out mTHP without splitting". - Kefeng Wang has significantly optimized the handling of arm64's permission page faults in the series "arch/mm/fault: accelerate pagefault when badaccess" "mm: remove arch's private VM_FAULT_BADMAP/BADACCESS" - GUP cleanups from David Hildenbrand in "mm/gup: consistently call it GUP-fast". - hugetlb fault code cleanups from Vishal Moola in "Hugetlb fault path to use struct vm_fault". - selftests build fixes from John Hubbard in the series "Fix selftests/mm build without requiring "make headers"". - Memory tiering fixes/improvements from Ho-Ren (Jack) Chuang in the series "Improved Memory Tier Creation for CPUless NUMA Nodes". Fixes the initialization code so that migration between different memory types works as intended. - David Hildenbrand has improved follow_pte() and fixed an errant driver in the series "mm: follow_pte() improvements and acrn follow_pte() fixes". - David also did some cleanup work on large folio mapcounts in his series "mm: mapcount for large folios + page_mapcount() cleanups". - Folio conversions in KSM in Alex Shi's series "transfer page to folio in KSM". - Barry Song has added some sysfs stats for monitoring multi-size THP's in the series "mm: add per-order mTHP alloc and swpout counters". - Some zswap cleanups from Yosry Ahmed in the series "zswap same-filled and limit checking cleanups". - Matthew Wilcox has been looking at buffer_head code and found the documentation to be lacking. The series is "Improve buffer head documentation". - Multi-size THPs get more work, this time from Lance Yang. His series "mm/madvise: enhance lazyfreeing with mTHP in madvise_free" optimizes the freeing of these things. - Kemeng Shi has added more userspace-visible writeback instrumentation in the series "Improve visibility of writeback". - Kemeng Shi then sent some maintenance work on top in the series "Fix and cleanups to page-writeback". - Matthew Wilcox reduces mmap_lock traffic in the anon vma code in the series "Improve anon_vma scalability for anon VMAs". Intel's test bot reported an improbable 3x improvement in one test. - SeongJae Park adds some DAMON feature work in the series "mm/damon: add a DAMOS filter type for page granularity access recheck" "selftests/damon: add DAMOS quota goal test" - Also some maintenance work in the series "mm/damon/paddr: simplify page level access re-check for pageout" "mm/damon: misc fixes and improvements" - David Hildenbrand has disabled some known-to-fail selftests ni the series "selftests: mm: cow: flag vmsplice() hugetlb tests as XFAIL". - memcg metadata storage optimizations from Shakeel Butt in "memcg: reduce memory consumption by memcg stats". - DAX fixes and maintenance work from Vishal Verma in the series "dax/bus.c: Fixups for dax-bus locking"" * tag 'mm-stable-2024-05-17-19-19' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (426 commits) memcg, oom: cleanup unused memcg_oom_gfp_mask and memcg_oom_order selftests/mm: hugetlb_madv_vs_map: avoid test skipping by querying hugepage size at runtime mm/hugetlb: add missing VM_FAULT_SET_HINDEX in hugetlb_wp mm/hugetlb: add missing VM_FAULT_SET_HINDEX in hugetlb_fault selftests: cgroup: add tests to verify the zswap writeback path mm: memcg: make alloc_mem_cgroup_per_node_info() return bool mm/damon/core: fix return value from damos_wmark_metric_value mm: do not update memcg stats for NR_{FILE/SHMEM}_PMDMAPPED selftests: cgroup: remove redundant enabling of memory controller Docs/mm/damon/maintainer-profile: allow posting patches based on damon/next tree Docs/mm/damon/maintainer-profile: change the maintainer's timezone from PST to PT Docs/mm/damon/design: use a list for supported filters Docs/admin-guide/mm/damon/usage: fix wrong schemes effective quota update command Docs/admin-guide/mm/damon/usage: fix wrong example of DAMOS filter matching sysfs file selftests/damon: classify tests for functionalities and regressions selftests/damon/_damon_sysfs: use 'is' instead of '==' for 'None' selftests/damon/_damon_sysfs: find sysfs mount point from /proc/mounts selftests/damon/_damon_sysfs: check errors from nr_schemes file reads mm/damon/core: initialize ->esz_bp from damos_quota_init_priv() selftests/damon: add a test for DAMOS quota goal ...
2024-04-29Merge tag 'for-netdev' of ↵Jakub Kicinski1-2/+20
https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next Daniel Borkmann says: ==================== pull-request: bpf-next 2024-04-29 We've added 147 non-merge commits during the last 32 day(s) which contain a total of 158 files changed, 9400 insertions(+), 2213 deletions(-). The main changes are: 1) Add an internal-only BPF per-CPU instruction for resolving per-CPU memory addresses and implement support in x86 BPF JIT. This allows inlining per-CPU array and hashmap lookups and the bpf_get_smp_processor_id() helper, from Andrii Nakryiko. 2) Add BPF link support for sk_msg and sk_skb programs, from Yonghong Song. 3) Optimize x86 BPF JIT's emit_mov_imm64, and add support for various atomics in bpf_arena which can be JITed as a single x86 instruction, from Alexei Starovoitov. 4) Add support for passing mark with bpf_fib_lookup helper, from Anton Protopopov. 5) Add a new bpf_wq API for deferring events and refactor sleepable bpf_timer code to keep common code where possible, from Benjamin Tissoires. 6) Fix BPF_PROG_TEST_RUN infra with regards to bpf_dummy_struct_ops programs to check when NULL is passed for non-NULLable parameters, from Eduard Zingerman. 7) Harden the BPF verifier's and/or/xor value tracking, from Harishankar Vishwanathan. 8) Introduce crypto kfuncs to make BPF programs able to utilize the kernel crypto subsystem, from Vadim Fedorenko. 9) Various improvements to the BPF instruction set standardization doc, from Dave Thaler. 10) Extend libbpf APIs to partially consume items from the BPF ringbuffer, from Andrea Righi. 11) Bigger batch of BPF selftests refactoring to use common network helpers and to drop duplicate code, from Geliang Tang. 12) Support bpf_tail_call_static() helper for BPF programs with GCC 13, from Jose E. Marchesi. 13) Add bpf_preempt_{disable,enable}() kfuncs in order to allow a BPF program to have code sections where preemption is disabled, from Kumar Kartikeya Dwivedi. 14) Allow invoking BPF kfuncs from BPF_PROG_TYPE_SYSCALL programs, from David Vernet. 15) Extend the BPF verifier to allow different input maps for a given bpf_for_each_map_elem() helper call in a BPF program, from Philo Lu. 16) Add support for PROBE_MEM32 and bpf_addr_space_cast instructions for riscv64 and arm64 JITs to enable BPF Arena, from Puranjay Mohan. 17) Shut up a false-positive KMSAN splat in interpreter mode by unpoison the stack memory, from Martin KaFai Lau. 18) Improve xsk selftest coverage with new tests on maximum and minimum hardware ring size configurations, from Tushar Vyavahare. 19) Various ReST man pages fixes as well as documentation and bash completion improvements for bpftool, from Rameez Rehman & Quentin Monnet. 20) Fix libbpf with regards to dumping subsequent char arrays, from Quentin Deslandes. * tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (147 commits) bpf, docs: Clarify PC use in instruction-set.rst bpf_helpers.h: Define bpf_tail_call_static when building with GCC bpf, docs: Add introduction for use in the ISA Internet Draft selftests/bpf: extend BPF_SOCK_OPS_RTT_CB test for srtt and mrtt_us bpf: add mrtt and srtt as BPF_SOCK_OPS_RTT_CB args selftests/bpf: dummy_st_ops should reject 0 for non-nullable params bpf: check bpf_dummy_struct_ops program params for test runs selftests/bpf: do not pass NULL for non-nullable params in dummy_st_ops selftests/bpf: adjust dummy_st_ops_success to detect additional error bpf: mark bpf_dummy_struct_ops.test_1 parameter as nullable selftests/bpf: Add ring_buffer__consume_n test. bpf: Add bpf_guard_preempt() convenience macro selftests: bpf: crypto: add benchmark for crypto functions selftests: bpf: crypto skcipher algo selftests bpf: crypto: add skcipher to bpf crypto bpf: make common crypto API for TC/XDP programs bpf: update the comment for BTF_FIELDS_MAX selftests/bpf: Fix wq test. selftests/bpf: Use make_sockaddr in test_sock_addr selftests/bpf: Use connect_to_addr in test_sock_addr ... ==================== Link: https://lore.kernel.org/r/20240429131657.19423-1-daniel@iogearbox.net Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-04-25mm: change inlined allocation helpers to account at the call siteSuren Baghdasaryan1-25/+8
Main goal of memory allocation profiling patchset is to provide accounting that is cheap enough to run in production. To achieve that we inject counters using codetags at the allocation call sites to account every time allocation is made. This injection allows us to perform accounting efficiently because injected counters are immediately available as opposed to the alternative methods, such as using _RET_IP_, which would require counter lookup and appropriate locking that makes accounting much more expensive. This method requires all allocation functions to inject separate counters at their call sites so that their callers can be individually accounted. Counter injection is implemented by allocation hooks which should wrap all allocation functions. Inlined functions which perform allocations but do not use allocation hooks are directly charged for the allocations they perform. In most cases these functions are just specialized allocation wrappers used from multiple places to allocate objects of a specific type. It would be more useful to do the accounting at their call sites instead. Instrument these helpers to do accounting at the call site. Simple inlined allocation wrappers are converted directly into macros. More complex allocators or allocators with documentation are converted into _noprof versions and allocation hooks are added. This allows memory allocation profiling mechanism to charge allocations to the callers of these functions. Link: https://lkml.kernel.org/r/20240415020731.1152108-1-surenb@google.com Signed-off-by: Suren Baghdasaryan <surenb@google.com> Acked-by: Jan Kara <jack@suse.cz> [jbd2] Cc: Anna Schumaker <anna@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Benjamin Tissoires <benjamin.tissoires@redhat.com> Cc: Christoph Lameter <cl@linux.com> Cc: David Rientjes <rientjes@google.com> Cc: David S. Miller <davem@davemloft.net> Cc: Dennis Zhou <dennis@kernel.org> Cc: Eric Dumazet <edumazet@google.com> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Jakub Kicinski <kuba@kernel.org> Cc: Jakub Sitnicki <jakub@cloudflare.com> Cc: Jiri Kosina <jikos@kernel.org> Cc: Joerg Roedel <joro@8bytes.org> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Kent Overstreet <kent.overstreet@linux.dev> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Paolo Abeni <pabeni@redhat.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Tejun Heo <tj@kernel.org> Cc: Theodore Ts'o <tytso@mit.edu> Cc: Trond Myklebust <trond.myklebust@hammerspace.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-04-24bpf: make common crypto API for TC/XDP programsVadim Fedorenko1-0/+1
Add crypto API support to BPF to be able to decrypt or encrypt packets in TC/XDP BPF programs. Special care should be taken for initialization part of crypto algo because crypto alloc) doesn't work with preemtion disabled, it can be run only in sleepable BPF program. Also async crypto is not supported because of the very same issue - TC/XDP BPF programs are not sleepable. Signed-off-by: Vadim Fedorenko <vadfed@meta.com> Link: https://lore.kernel.org/r/20240422225024.2847039-2-vadfed@meta.com Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2024-04-24bpf: update the comment for BTF_FIELDS_MAXHaiyue Wang1-1/+1
The commit d56b63cf0c0f ("bpf: add support for bpf_wq user type") changes the fields support number to 11, just sync the comment. Signed-off-by: Haiyue Wang <haiyue.wang@intel.com> Acked-by: Yonghong Song <yonghong.song@linux.dev> Link: https://lore.kernel.org/r/20240424054526.8031-1-haiyue.wang@intel.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-04-23bpf: allow struct bpf_wq to be embedded in arraymaps and hashmapsBenjamin Tissoires1-0/+2
Currently bpf_wq_cancel_and_free() is just a placeholder as there is no memory allocation for bpf_wq just yet. Again, duplication of the bpf_timer approach Signed-off-by: Benjamin Tissoires <bentiss@kernel.org> Link: https://lore.kernel.org/r/20240420-bpf_wq-v2-9-6c986a5a741f@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-04-23bpf: add support for bpf_wq user typeBenjamin Tissoires1-1/+10
Mostly a copy/paste from the bpf_timer API, without the initialization and free, as they will be done in a separate patch. Signed-off-by: Benjamin Tissoires <bentiss@kernel.org> Link: https://lore.kernel.org/r/20240420-bpf_wq-v2-5-6c986a5a741f@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-04-10bpf: Add bpf_link support for sk_msg and sk_skb progsYonghong Song1-0/+6
Add bpf_link support for sk_msg and sk_skb programs. We have an internal request to support bpf_link for sk_msg programs so user space can have a uniform handling with bpf_link based libbpf APIs. Using bpf_link based libbpf API also has a benefit which makes system robust by decoupling prog life cycle and attachment life cycle. Reviewed-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Yonghong Song <yonghong.song@linux.dev> Link: https://lore.kernel.org/r/20240410043527.3737160-1-yonghong.song@linux.dev Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-04-04Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski1-1/+15
Cross-merge networking fixes after downstream PR. Conflicts: net/ipv4/ip_gre.c 17af420545a7 ("erspan: make sure erspan_base_hdr is present in skb->head") 5832c4a77d69 ("ip_tunnel: convert __be16 tunnel flags to bitmaps") https://lore.kernel.org/all/20240402103253.3b54a1cf@canb.auug.org.au/ Adjacent changes: net/ipv6/ip6_fib.c d21d40605bca ("ipv6: Fix infinite recursion in fib6_dump_done().") 5fc68320c1fb ("ipv6: remove RTNL protection from inet6_dump_fib()") Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-03-28bpf: support deferring bpf_link dealloc to after RCU grace periodAndrii Nakryiko1-1/+15
BPF link for some program types is passed as a "context" which can be used by those BPF programs to look up additional information. E.g., for multi-kprobes and multi-uprobes, link is used to fetch BPF cookie values. Because of this runtime dependency, when bpf_link refcnt drops to zero there could still be active BPF programs running accessing link data. This patch adds generic support to defer bpf_link dealloc callback to after RCU GP, if requested. This is done by exposing two different deallocation callbacks, one synchronous and one deferred. If deferred one is provided, bpf_link_free() will schedule dealloc_deferred() callback to happen after RCU GP. BPF is using two flavors of RCU: "classic" non-sleepable one and RCU tasks trace one. The latter is used when sleepable BPF programs are used. bpf_link_free() accommodates that by checking underlying BPF program's sleepable flag, and goes either through normal RCU GP only for non-sleepable, or through RCU tasks trace GP *and* then normal RCU GP (taking into account rcu_trace_implies_rcu_gp() optimization), if BPF program is sleepable. We use this for multi-kprobe and multi-uprobe links, which dereference link during program run. We also preventively switch raw_tp link to use deferred dealloc callback, as upcoming changes in bpf-next tree expose raw_tp link data (specifically, cookie value) to BPF program at runtime as well. Fixes: 0dcac2725406 ("bpf: Add multi kprobe link") Fixes: 89ae89f53d20 ("bpf: Add multi uprobe link") Reported-by: syzbot+981935d9485a560bfbcb@syzkaller.appspotmail.com Reported-by: syzbot+2cb5a6c573e98db598cc@syzkaller.appspotmail.com Reported-by: syzbot+62d8b26793e8a2bd0516@syzkaller.appspotmail.com Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Jiri Olsa <jolsa@kernel.org> Link: https://lore.kernel.org/r/20240328052426.3042617-2-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-03-19bpf: support BPF cookie in raw tracepoint (raw_tp, tp_btf) programsAndrii Nakryiko1-0/+1
Wire up BPF cookie for raw tracepoint programs (both BTF and non-BTF aware variants). This brings them up to part w.r.t. BPF cookie usage with classic tracepoint and fentry/fexit programs. Acked-by: Stanislav Fomichev <sdf@google.com> Acked-by: Eduard Zingerman <eddyz87@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Message-ID: <20240319233852.1977493-4-andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-03-19bpf: pass whole link instead of prog when triggering raw tracepointAndrii Nakryiko1-0/+5
Instead of passing prog as an argument to bpf_trace_runX() helpers, that are called from tracepoint triggering calls, store BPF link itself (struct bpf_raw_tp_link for raw tracepoints). This will allow to pass extra information like BPF cookie into raw tracepoint registration. Instead of replacing `struct bpf_prog *prog = __data;` with corresponding `struct bpf_raw_tp_link *link = __data;` assignment in `__bpf_trace_##call` I just passed `__data` through into underlying bpf_trace_runX() call. This works well because we implicitly cast `void *`, and it also avoids naming clashes with arguments coming from tracepoint's "proto" list. We could have run into the same problem with "prog", we just happened to not have a tracepoint that has "prog" input argument. We are less lucky with "link", as there are tracepoints using "link" argument name already. So instead of trying to avoid naming conflicts, let's just remove intermediate local variable. It doesn't hurt readibility, it's either way a bit of a maze of calls and macros, that requires careful reading. Acked-by: Stanislav Fomichev <sdf@google.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Message-ID: <20240319233852.1977493-3-andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-03-18bpf: Check return from set_memory_rox()Christophe Leroy1-1/+1
arch_protect_bpf_trampoline() and alloc_new_pack() call set_memory_rox() which can fail, leading to unprotected memory. Take into account return from set_memory_rox() function and add __must_check flag to arch_protect_bpf_trampoline(). Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Reviewed-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/fe1c163c83767fde5cab31d209a4a6be3ddb3a73.1710574353.git.christophe.leroy@csgroup.eu Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2024-03-18bpf: Remove arch_unprotect_bpf_trampoline()Christophe Leroy1-1/+0
Last user of arch_unprotect_bpf_trampoline() was removed by commit 187e2af05abe ("bpf: struct_ops supports more than one page for trampolines.") Remove arch_unprotect_bpf_trampoline() Reported-by: Daniel Borkmann <daniel@iogearbox.net> Fixes: 187e2af05abe ("bpf: struct_ops supports more than one page for trampolines.") Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Link: https://lore.kernel.org/r/42c635bb54d3af91db0f9b85d724c7c290069f67.1710574353.git.christophe.leroy@csgroup.eu Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2024-03-11bpf: move sleepable flag from bpf_prog_aux to bpf_progAndrii Nakryiko1-4/+4
prog->aux->sleepable is checked very frequently as part of (some) BPF program run hot paths. So this extra aux indirection seems wasteful and on busy systems might cause unnecessary memory cache misses. Let's move sleepable flag into prog itself to eliminate unnecessary pointer dereference. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Jiri Olsa <jolsa@kernel.org> Message-ID: <20240309004739.2961431-1-andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-03-11bpf: Recognize btf_decl_tag("arg: Arena") as PTR_TO_ARENA.Alexei Starovoitov1-0/+1
In global bpf functions recognize btf_decl_tag("arg:arena") as PTR_TO_ARENA. Note, when the verifier sees: __weak void foo(struct bar *p) it recognizes 'p' as PTR_TO_MEM and 'struct bar' has to be a struct with scalars. Hence the only way to use arena pointers in global functions is to tag them with "arg:arena". Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Link: https://lore.kernel.org/bpf/20240308010812.89848-7-alexei.starovoitov@gmail.com
2024-03-11bpf: Recognize addr_space_cast instruction in the verifier.Alexei Starovoitov1-0/+1
rY = addr_space_cast(rX, 0, 1) tells the verifier that rY->type = PTR_TO_ARENA. Any further operations on PTR_TO_ARENA register have to be in 32-bit domain. The verifier will mark load/store through PTR_TO_ARENA with PROBE_MEM32. JIT will generate them as kern_vm_start + 32bit_addr memory accesses. rY = addr_space_cast(rX, 1, 0) tells the verifier that rY->type = unknown scalar. If arena->map_flags has BPF_F_NO_USER_CONV set then convert cast_user to mov32 as well. Otherwise JIT will convert it to: rY = (u32)rX; if (rY) rY |= arena->user_vm_start & ~(u64)~0U; Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20240308010812.89848-6-alexei.starovoitov@gmail.com
2024-03-11bpf: Add x86-64 JIT support for PROBE_MEM32 pseudo instructions.Alexei Starovoitov1-0/+1
Add support for [LDX | STX | ST], PROBE_MEM32, [B | H | W | DW] instructions. They are similar to PROBE_MEM instructions with the following differences: - PROBE_MEM has to check that the address is in the kernel range with src_reg + insn->off >= TASK_SIZE_MAX + PAGE_SIZE check - PROBE_MEM doesn't support store - PROBE_MEM32 relies on the verifier to clear upper 32-bit in the register - PROBE_MEM32 adds 64-bit kern_vm_start address (which is stored in %r12 in the prologue) Due to bpf_arena constructions such %r12 + %reg + off16 access is guaranteed to be within arena virtual range, so no address check at run-time. - PROBE_MEM32 allows STX and ST. If they fault the store is a nop. When LDX faults the destination register is zeroed. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Link: https://lore.kernel.org/bpf/20240308010812.89848-4-alexei.starovoitov@gmail.com
2024-03-11bpf: Introduce bpf_arena.Alexei Starovoitov1-2/+5
Introduce bpf_arena, which is a sparse shared memory region between the bpf program and user space. Use cases: 1. User space mmap-s bpf_arena and uses it as a traditional mmap-ed anonymous region, like memcached or any key/value storage. The bpf program implements an in-kernel accelerator. XDP prog can search for a key in bpf_arena and return a value without going to user space. 2. The bpf program builds arbitrary data structures in bpf_arena (hash tables, rb-trees, sparse arrays), while user space consumes it. 3. bpf_arena is a "heap" of memory from the bpf program's point of view. The user space may mmap it, but bpf program will not convert pointers to user base at run-time to improve bpf program speed. Initially, the kernel vm_area and user vma are not populated. User space can fault in pages within the range. While servicing a page fault, bpf_arena logic will insert a new page into the kernel and user vmas. The bpf program can allocate pages from that region via bpf_arena_alloc_pages(). This kernel function will insert pages into the kernel vm_area. The subsequent fault-in from user space will populate that page into the user vma. The BPF_F_SEGV_ON_FAULT flag at arena creation time can be used to prevent fault-in from user space. In such a case, if a page is not allocated by the bpf program and not present in the kernel vm_area, the user process will segfault. This is useful for use cases 2 and 3 above. bpf_arena_alloc_pages() is similar to user space mmap(). It allocates pages either at a specific address within the arena or allocates a range with the maple tree. bpf_arena_free_pages() is analogous to munmap(), which frees pages and removes the range from the kernel vm_area and from user process vmas. bpf_arena can be used as a bpf program "heap" of up to 4GB. The speed of bpf program is more important than ease of sharing with user space. This is use case 3. In such a case, the BPF_F_NO_USER_CONV flag is recommended. It will tell the verifier to treat the rX = bpf_arena_cast_user(rY) instruction as a 32-bit move wX = wY, which will improve bpf prog performance. Otherwise, bpf_arena_cast_user is translated by JIT to conditionally add the upper 32 bits of user vm_start (if the pointer is not NULL) to arena pointers before they are stored into memory. This way, user space sees them as valid 64-bit pointers. Diff https://github.com/llvm/llvm-project/pull/84410 enables LLVM BPF backend generate the bpf_addr_space_cast() instruction to cast pointers between address_space(1) which is reserved for bpf_arena pointers and default address space zero. All arena pointers in a bpf program written in C language are tagged as __attribute__((address_space(1))). Hence, clang provides helpful diagnostics when pointers cross address space. Libbpf and the kernel support only address_space == 1. All other address space identifiers are reserved. rX = bpf_addr_space_cast(rY, /* dst_as */ 1, /* src_as */ 0) tells the verifier that rX->type = PTR_TO_ARENA. Any further operations on PTR_TO_ARENA register have to be in the 32-bit domain. The verifier will mark load/store through PTR_TO_ARENA with PROBE_MEM32. JIT will generate them as kern_vm_start + 32bit_addr memory accesses. The behavior is similar to copy_from_kernel_nofault() except that no address checks are necessary. The address is guaranteed to be in the 4GB range. If the page is not present, the destination register is zeroed on read, and the operation is ignored on write. rX = bpf_addr_space_cast(rY, 0, 1) tells the verifier that rX->type = unknown scalar. If arena->map_flags has BPF_F_NO_USER_CONV set, then the verifier converts such cast instructions to mov32. Otherwise, JIT will emit native code equivalent to: rX = (u32)rY; if (rY) rX |= clear_lo32_bits(arena->user_vm_start); /* replace hi32 bits in rX */ After such conversion, the pointer becomes a valid user pointer within bpf_arena range. The user process can access data structures created in bpf_arena without any additional computations. For example, a linked list built by a bpf program can be walked natively by user space. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Reviewed-by: Barret Rhoden <brho@google.com> Link: https://lore.kernel.org/bpf/20240308010812.89848-2-alexei.starovoitov@gmail.com
2024-03-07bpf: Plumb get_unmapped_area() callback into bpf_map_opsAlexei Starovoitov1-0/+3
Subsequent patches introduce bpf_arena that imposes special alignment requirements on address selection. Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/r/20240307031228.42896-4-alexei.starovoitov@gmail.com Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2024-03-04bpf: struct_ops supports more than one page for trampolines.Kui-Feng Lee1-1/+3
The BPF struct_ops previously only allowed one page of trampolines. Each function pointer of a struct_ops is implemented by a struct_ops bpf program. Each struct_ops bpf program requires a trampoline. The following selftest patch shows each page can hold a little more than 20 trampolines. While one page is more than enough for the tcp-cc usecase, the sched_ext use case shows that one page is not always enough and hits the one page limit. This patch overcomes the one page limit by allocating another page when needed and it is limited to a total of MAX_IMAGE_PAGES (8) pages which is more than enough for reasonable usages. The variable st_map->image has been changed to st_map->image_pages, and its type has been changed to an array of pointers to pages. Signed-off-by: Kui-Feng Lee <thinker.li@gmail.com> Link: https://lore.kernel.org/r/20240224223418.526631-3-thinker.li@gmail.com Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2024-02-21bpf: Shrink size of struct bpf_map/bpf_array.Alexei Starovoitov1-9/+3
Back in 2018 the commit be95a845cc44 ("bpf: avoid false sharing of map refcount with max_entries") added ____cacheline_aligned to "struct bpf_map" to make sure that fields like refcnt don't share a cache line with max_entries that is used to bounds check map access. That was done to make spectre style attacks harder. The main mitigation is done via code similar to array_index_nospec(), of course. This was an additional precaution. It increased the size of "struct bpf_map" a little, but it's affect on all other maps (like array) is significant, since "struct bpf_map" is typically the first member in other map types. Undo this ____cacheline_aligned tag. Instead move freeze_mutex field around, so that refcnt and max_entries are still in different cache lines. The main effect is seen in sizeof(struct bpf_array) that reduces from 320 to 248 bytes. BEFORE: struct bpf_map { const struct bpf_map_ops * ops; /* 0 8 */ ... char name[16]; /* 96 16 */ /* XXX 16 bytes hole, try to pack */ /* --- cacheline 2 boundary (128 bytes) --- */ atomic64_t refcnt __attribute__((__aligned__(64))); /* 128 8 */ ... /* size: 256, cachelines: 4, members: 30 */ /* sum members: 232, holes: 1, sum holes: 16 */ /* padding: 8 */ /* paddings: 1, sum paddings: 2 */ } __attribute__((__aligned__(64))); struct bpf_array { struct bpf_map map; /* 0 256 */ ... /* size: 320, cachelines: 5, members: 5 */ /* padding: 48 */ /* paddings: 1, sum paddings: 8 */ } __attribute__((__aligned__(64))); AFTER: struct bpf_map { /* size: 232, cachelines: 4, members: 30 */ /* paddings: 1, sum paddings: 2 */ /* last cacheline: 40 bytes */ }; struct bpf_array { /* size: 248, cachelines: 4, members: 5 */ /* last cacheline: 56 bytes */ }; Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Yonghong Song <yonghong.song@linux.dev> Link: https://lore.kernel.org/bpf/20240220235001.57411-1-alexei.starovoitov@gmail.com
2024-02-13bpf: Create argument information for nullable arguments.Kui-Feng Lee1-0/+21
Collect argument information from the type information of stub functions to mark arguments of BPF struct_ops programs with PTR_MAYBE_NULL if they are nullable. A nullable argument is annotated by suffixing "__nullable" at the argument name of stub function. For nullable arguments, this patch sets a struct bpf_ctx_arg_aux to label their reg_type with PTR_TO_BTF_ID | PTR_TRUSTED | PTR_MAYBE_NULL. This makes the verifier to check programs and ensure that they properly check the pointer. The programs should check if the pointer is null before accessing the pointed memory. The implementer of a struct_ops type should annotate the arguments that can be null. The implementer should define a stub function (empty) as a placeholder for each defined operator. The name of a stub function should be in the pattern "<st_op_type>__<operator name>". For example, for test_maybe_null of struct bpf_testmod_ops, it's stub function name should be "bpf_testmod_ops__test_maybe_null". You mark an argument nullable by suffixing the argument name with "__nullable" at the stub function. Since we already has stub functions for kCFI, we just reuse these stub functions with the naming convention mentioned earlier. These stub functions with the naming convention is only required if there are nullable arguments to annotate. For functions having not nullable arguments, stub functions are not necessary for the purpose of this patch. This patch will prepare a list of struct bpf_ctx_arg_aux, aka arg_info, for each member field of a struct_ops type. "arg_info" will be assigned to "prog->aux->ctx_arg_info" of BPF struct_ops programs in check_struct_ops_btf_id() so that it can be used by btf_ctx_access() later to set reg_type properly for the verifier. Signed-off-by: Kui-Feng Lee <thinker.li@gmail.com> Link: https://lore.kernel.org/r/20240209023750.1153905-4-thinker.li@gmail.com Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2024-02-13bpf: add btf pointer to struct bpf_ctx_arg_aux.Kui-Feng Lee1-0/+1
Enable the providers to use types defined in a module instead of in the kernel (btf_vmlinux). Signed-off-by: Kui-Feng Lee <thinker.li@gmail.com> Link: https://lore.kernel.org/r/20240209023750.1153905-2-thinker.li@gmail.com Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2024-01-29bpf: Remove unused field "mod" in struct bpf_trampolineMenglong Dong1-1/+0
It seems that the field "mod" in struct bpf_trampoline is not used anywhere after the commit 31bf1dbccfb0 ("bpf: Fix attaching fentry/fexit/fmod_ret/lsm to modules"). So we can just remove it now. Fixes: 31bf1dbccfb0 ("bpf: Fix attaching fentry/fexit/fmod_ret/lsm to modules") Signed-off-by: Menglong Dong <dongmenglong.8@bytedance.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Jiri Olsa <jolsa@kernel.org> Link: https://lore.kernel.org/bpf/20240128055443.413291-1-dongmenglong.8@bytedance.com
2024-01-24bpf,lsm: Add BPF token LSM hooksAndrii Nakryiko1-0/+3
Wire up bpf_token_create and bpf_token_free LSM hooks, which allow to allocate LSM security blob (we add `void *security` field to struct bpf_token for that), but also control who can instantiate BPF token. This follows existing pattern for BPF map and BPF prog. Also add security_bpf_token_allow_cmd() and security_bpf_token_capable() LSM hooks that allow LSM implementation to control and negate (if necessary) BPF token's delegation of a specific bpf_cmd and capability, respectively. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Paul Moore <paul@paul-moore.com> Link: https://lore.kernel.org/bpf/20240124022127.2379740-12-andrii@kernel.org