#
66c84731 |
|
08-Mar-2024 |
Andrii Nakryiko <andrii@kernel.org> |
bpf: move sleepable flag from bpf_prog_aux to bpf_prog 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>
|
#
187e2af0 |
|
24-Feb-2024 |
Kui-Feng Lee <thinker.li@gmail.com> |
bpf: struct_ops supports more than one page for trampolines. 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>
|
#
f6be98d1 |
|
19-Jan-2024 |
Kui-Feng Lee <thinker.li@gmail.com> |
bpf, net: switch to dynamic registration Replace the static list of struct_ops types with per-btf struct_ops_tab to enable dynamic registration. Both bpf_dummy_ops and bpf_tcp_ca now utilize the registration function instead of being listed in bpf_struct_ops_types.h. Cc: netdev@vger.kernel.org Signed-off-by: Kui-Feng Lee <thinker.li@gmail.com> Link: https://lore.kernel.org/r/20240119225005.668602-12-thinker.li@gmail.com Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
|
#
4c5763ed |
|
19-Jan-2024 |
Kui-Feng Lee <thinker.li@gmail.com> |
bpf, net: introduce bpf_struct_ops_desc. Move some of members of bpf_struct_ops to bpf_struct_ops_desc. type_id is unavailabe in bpf_struct_ops anymore. Modules should get it from the btf received by kmod's init function. Cc: netdev@vger.kernel.org Signed-off-by: Kui-Feng Lee <thinker.li@gmail.com> Link: https://lore.kernel.org/r/20240119225005.668602-4-thinker.li@gmail.com Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
|
#
2cd3e377 |
|
15-Dec-2023 |
Peter Zijlstra <peterz@infradead.org> |
x86/cfi,bpf: Fix bpf_struct_ops CFI BPF struct_ops uses __arch_prepare_bpf_trampoline() to write trampolines for indirect function calls. These tramplines much have matching CFI. In order to obtain the correct CFI hash for the various methods, add a matching structure that contains stub functions, the compiler will generate correct CFI which we can pilfer for the trampolines. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20231215092707.566977112@infradead.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
#
82583daa |
|
06-Dec-2023 |
Song Liu <song@kernel.org> |
bpf: Add helpers for trampoline image management As BPF trampoline of different archs moves from bpf_jit_[alloc|free]_exec() to bpf_prog_pack_[alloc|free](), we need to use different _alloc, _free for different archs during the transition. Add the following helpers for this transition: void *arch_alloc_bpf_trampoline(unsigned int size); void arch_free_bpf_trampoline(void *image, unsigned int size); void arch_protect_bpf_trampoline(void *image, unsigned int size); void arch_unprotect_bpf_trampoline(void *image, unsigned int size); The fallback version of these helpers require size <= PAGE_SIZE, but they are only called with size == PAGE_SIZE. They will be called with size < PAGE_SIZE when arch_bpf_trampoline_size() helper is introduced later. Signed-off-by: Song Liu <song@kernel.org> Acked-by: Ilya Leoshkevich <iii@linux.ibm.com> Tested-by: Ilya Leoshkevich <iii@linux.ibm.com> # on s390x Acked-by: Jiri Olsa <jolsa@kernel.org> Link: https://lore.kernel.org/r/20231206224054.492250-4-song@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
#
b7e852a9 |
|
03-Apr-2023 |
Alexei Starovoitov <ast@kernel.org> |
bpf: Remove unused arguments from btf_struct_access(). Remove unused arguments from btf_struct_access() callback. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: David Vernet <void@manifault.com> Link: https://lore.kernel.org/bpf/20230404045029.82870-3-alexei.starovoitov@gmail.com
|
#
7d64c513 |
|
03-Apr-2023 |
Alexei Starovoitov <ast@kernel.org> |
bpf: Invoke btf_struct_access() callback only for writes. Remove duplicated if (atype == BPF_READ) btf_struct_access() from btf_struct_access() callback and invoke it only for writes. This is possible to do because currently btf_struct_access() custom callback always delegates to generic btf_struct_access() helper for BPF_READ accesses. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: David Vernet <void@manifault.com> Link: https://lore.kernel.org/bpf/20230404045029.82870-2-alexei.starovoitov@gmail.com
|
#
7dd88059 |
|
25-Jan-2023 |
David Vernet <void@manifault.com> |
bpf/selftests: Verify struct_ops prog sleepable behavior In a set of prior changes, we added the ability for struct_ops programs to be sleepable. This patch enhances the dummy_st_ops selftest suite to validate this behavior by adding a new sleepable struct_ops entry to dummy_st_ops. Signed-off-by: David Vernet <void@manifault.com> Link: https://lore.kernel.org/r/20230125164735.785732-5-void@manifault.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
#
d48567c9 |
|
25-Oct-2022 |
Peter Zijlstra <peterz@infradead.org> |
mm: Introduce set_memory_rox() Because endlessly repeating: set_memory_ro() set_memory_x() is getting tedious. Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/Y1jek64pXOsougmz@hirez.programming.kicks-ass.net
|
#
6728aea7 |
|
14-Nov-2022 |
Kumar Kartikeya Dwivedi <memxor@gmail.com> |
bpf: Refactor btf_struct_access Instead of having to pass multiple arguments that describe the register, pass the bpf_reg_state into the btf_struct_access callback. Currently, all call sites simply reuse the btf and btf_id of the reg they want to check the access of. The only exception to this pattern is the callsite in check_ptr_to_map_access, hence for that case create a dummy reg to simulate PTR_TO_BTF_ID access. Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Link: https://lore.kernel.org/r/20221114191547.1694267-8-memxor@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
#
f7e0beaf |
|
10-May-2022 |
Kui-Feng Lee <kuifeng@fb.com> |
bpf, x86: Generate trampolines from bpf_tramp_links Replace struct bpf_tramp_progs with struct bpf_tramp_links to collect struct bpf_tramp_link(s) for a trampoline. struct bpf_tramp_link extends bpf_link to act as a linked list node. arch_prepare_bpf_trampoline() accepts a struct bpf_tramp_links to collects all bpf_tramp_link(s) that a trampoline should call. Change BPF trampoline and bpf_struct_ops to pass bpf_tramp_links instead of bpf_tramp_progs. Signed-off-by: Kui-Feng Lee <kuifeng@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220510205923.3206889-2-kuifeng@fb.com
|
#
c6f1bfe8 |
|
27-Jan-2022 |
Yonghong Song <yhs@fb.com> |
bpf: reject program if a __user tagged memory accessed in kernel way BPF verifier supports direct memory access for BPF_PROG_TYPE_TRACING type of bpf programs, e.g., a->b. If "a" is a pointer pointing to kernel memory, bpf verifier will allow user to write code in C like a->b and the verifier will translate it to a kernel load properly. If "a" is a pointer to user memory, it is expected that bpf developer should be bpf_probe_read_user() helper to get the value a->b. Without utilizing BTF __user tagging information, current verifier will assume that a->b is a kernel memory access and this may generate incorrect result. Now BTF contains __user information, it can check whether the pointer points to a user memory or not. If it is, the verifier can reject the program and force users to use bpf_probe_read_user() helper explicitly. In the future, we can easily extend btf_add_space for other address space tagging, for example, rcu/percpu etc. Signed-off-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/r/20220127154606.654961-1-yhs@fb.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
#
c196906d |
|
25-Oct-2021 |
Hou Tao <houtao1@huawei.com> |
bpf: Add dummy BPF STRUCT_OPS for test purpose Currently the test of BPF STRUCT_OPS depends on the specific bpf implementation of tcp_congestion_ops, but it can not cover all basic functionalities (e.g, return value handling), so introduce a dummy BPF STRUCT_OPS for test purpose. Loading a bpf_dummy_ops implementation from userspace is prohibited, and its only purpose is to run BPF_PROG_TYPE_STRUCT_OPS program through bpf(BPF_PROG_TEST_RUN). Now programs for test_1() & test_2() are supported. The following three cases are exercised in bpf_dummy_struct_ops_test_run(): (1) test and check the value returned from state arg in test_1(state) The content of state is copied from userspace pointer and copied back after calling test_1(state). The user pointer is saved in an u64 array and the array address is passed through ctx_in. (2) test and check the return value of test_1(NULL) Just simulate the case in which an invalid input argument is passed in. (3) test multiple arguments passing in test_2(state, ...) 5 arguments are passed through ctx_in in form of u64 array. The first element of array is userspace pointer of state and others 4 arguments follow. Signed-off-by: Hou Tao <houtao1@huawei.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/20211025064025.2567443-4-houtao1@huawei.com
|