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2024-04-26bpf: verifier: prevent userspace memory accessPuranjay Mohan1-0/+9
With BPF_PROBE_MEM, BPF allows de-referencing an untrusted pointer. To thwart invalid memory accesses, the JITs add an exception table entry for all such accesses. But in case the src_reg + offset is a userspace address, the BPF program might read that memory if the user has mapped it. Make the verifier add guard instructions around such memory accesses and skip the load if the address falls into the userspace region. The JITs need to implement bpf_arch_uaddress_limit() to define where the userspace addresses end for that architecture or TASK_SIZE is taken as default. The implementation is as follows: REG_AX = SRC_REG if(offset) REG_AX += offset; REG_AX >>= 32; if (REG_AX <= (uaddress_limit >> 32)) DST_REG = 0; else DST_REG = *(size *)(SRC_REG + offset); Comparing just the upper 32 bits of the load address with the upper 32 bits of uaddress_limit implies that the values are being aligned down to a 4GB boundary before comparison. The above means that all loads with address <= uaddress_limit + 4GB are skipped. This is acceptable because there is a large hole (much larger than 4GB) between userspace and kernel space memory, therefore a correctly functioning BPF program should not access this 4GB memory above the userspace. Let's analyze what this patch does to the following fentry program dereferencing an untrusted pointer: SEC("fentry/tcp_v4_connect") int BPF_PROG(fentry_tcp_v4_connect, struct sock *sk) { *(volatile long *)sk; return 0; } BPF Program before | BPF Program after ------------------ | ----------------- 0: (79) r1 = *(u64 *)(r1 +0) 0: (79) r1 = *(u64 *)(r1 +0) ----------------------------------------------------------------------- 1: (79) r1 = *(u64 *)(r1 +0) --\ 1: (bf) r11 = r1 ----------------------------\ \ 2: (77) r11 >>= 32 2: (b7) r0 = 0 \ \ 3: (b5) if r11 <= 0x8000 goto pc+2 3: (95) exit \ \-> 4: (79) r1 = *(u64 *)(r1 +0) \ 5: (05) goto pc+1 \ 6: (b7) r1 = 0 \-------------------------------------- 7: (b7) r0 = 0 8: (95) exit As you can see from above, in the best case (off=0), 5 extra instructions are emitted. Now, we analyze the same program after it has gone through the JITs of ARM64 and RISC-V architectures. We follow the single load instruction that has the untrusted pointer and see what instrumentation has been added around it. x86-64 JIT ========== JIT's Instrumentation (upstream) --------------------- 0: nopl 0x0(%rax,%rax,1) 5: xchg %ax,%ax 7: push %rbp 8: mov %rsp,%rbp b: mov 0x0(%rdi),%rdi --------------------------------- f: movabs $0x800000000000,%r11 19: cmp %r11,%rdi 1c: jb 0x000000000000002a 1e: mov %rdi,%r11 21: add $0x0,%r11 28: jae 0x000000000000002e 2a: xor %edi,%edi 2c: jmp 0x0000000000000032 2e: mov 0x0(%rdi),%rdi --------------------------------- 32: xor %eax,%eax 34: leave 35: ret The x86-64 JIT already emits some instructions to protect against user memory access. This patch doesn't make any changes for the x86-64 JIT. ARM64 JIT ========= No Intrumentation Verifier's Instrumentation (upstream) (This patch) ----------------- -------------------------- 0: add x9, x30, #0x0 0: add x9, x30, #0x0 4: nop 4: nop 8: paciasp 8: paciasp c: stp x29, x30, [sp, #-16]! c: stp x29, x30, [sp, #-16]! 10: mov x29, sp 10: mov x29, sp 14: stp x19, x20, [sp, #-16]! 14: stp x19, x20, [sp, #-16]! 18: stp x21, x22, [sp, #-16]! 18: stp x21, x22, [sp, #-16]! 1c: stp x25, x26, [sp, #-16]! 1c: stp x25, x26, [sp, #-16]! 20: stp x27, x28, [sp, #-16]! 20: stp x27, x28, [sp, #-16]! 24: mov x25, sp 24: mov x25, sp 28: mov x26, #0x0 28: mov x26, #0x0 2c: sub x27, x25, #0x0 2c: sub x27, x25, #0x0 30: sub sp, sp, #0x0 30: sub sp, sp, #0x0 34: ldr x0, [x0] 34: ldr x0, [x0] -------------------------------------------------------------------------------- 38: ldr x0, [x0] ----------\ 38: add x9, x0, #0x0 -----------------------------------\\ 3c: lsr x9, x9, #32 3c: mov x7, #0x0 \\ 40: cmp x9, #0x10, lsl #12 40: mov sp, sp \\ 44: b.ls 0x0000000000000050 44: ldp x27, x28, [sp], #16 \\--> 48: ldr x0, [x0] 48: ldp x25, x26, [sp], #16 \ 4c: b 0x0000000000000054 4c: ldp x21, x22, [sp], #16 \ 50: mov x0, #0x0 50: ldp x19, x20, [sp], #16 \--------------------------------------- 54: ldp x29, x30, [sp], #16 54: mov x7, #0x0 58: add x0, x7, #0x0 58: mov sp, sp 5c: autiasp 5c: ldp x27, x28, [sp], #16 60: ret 60: ldp x25, x26, [sp], #16 64: nop 64: ldp x21, x22, [sp], #16 68: ldr x10, 0x0000000000000070 68: ldp x19, x20, [sp], #16 6c: br x10 6c: ldp x29, x30, [sp], #16 70: add x0, x7, #0x0 74: autiasp 78: ret 7c: nop 80: ldr x10, 0x0000000000000088 84: br x10 There are 6 extra instructions added in ARM64 in the best case. This will become 7 in the worst case (off != 0). RISC-V JIT (RISCV_ISA_C Disabled) ========== No Intrumentation Verifier's Instrumentation (upstream) (This patch) ----------------- -------------------------- 0: nop 0: nop 4: nop 4: nop 8: li a6, 33 8: li a6, 33 c: addi sp, sp, -16 c: addi sp, sp, -16 10: sd s0, 8(sp) 10: sd s0, 8(sp) 14: addi s0, sp, 16 14: addi s0, sp, 16 18: ld a0, 0(a0) 18: ld a0, 0(a0) --------------------------------------------------------------- 1c: ld a0, 0(a0) --\ 1c: mv t0, a0 --------------------------\ \ 20: srli t0, t0, 32 20: li a5, 0 \ \ 24: lui t1, 4096 24: ld s0, 8(sp) \ \ 28: sext.w t1, t1 28: addi sp, sp, 16 \ \ 2c: bgeu t1, t0, 12 2c: sext.w a0, a5 \ \--> 30: ld a0, 0(a0) 30: ret \ 34: j 8 \ 38: li a0, 0 \------------------------------ 3c: li a5, 0 40: ld s0, 8(sp) 44: addi sp, sp, 16 48: sext.w a0, a5 4c: ret There are 7 extra instructions added in RISC-V. Fixes: 800834285361 ("bpf, arm64: Add BPF exception tables") Reported-by: Breno Leitao <leitao@debian.org> Suggested-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Puranjay Mohan <puranjay12@gmail.com> Link: https://lore.kernel.org/r/20240424100210.11982-2-puranjay@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-03-12bpf: move sleepable flag from bpf_prog_aux to bpf_progAndrii Nakryiko1-1/+1
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>
2024-03-12bpf: hardcode BPF_PROG_PACK_SIZE to 2MB * num_possible_nodes()Puranjay Mohan1-1/+6
On some architectures like ARM64, PMD_SIZE can be really large in some configurations. Like with CONFIG_ARM64_64K_PAGES=y the PMD_SIZE is 512MB. Use 2MB * num_possible_nodes() as the size for allocations done through the prog pack allocator. On most architectures, PMD_SIZE will be equal to 2MB in case of 4KB pages and will be greater than 2MB for bigger page sizes. Fixes: ea2babac63d4 ("bpf: Simplify bpf_prog_pack_[size|mask]") Reported-by: "kernelci.org bot" <bot@kernelci.org> Closes: https://lore.kernel.org/all/7e216c88-77ee-47b8-becc-a0f780868d3c@sirena.org.uk/ Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202403092219.dhgcuz2G-lkp@intel.com/ Suggested-by: Song Liu <song@kernel.org> Signed-off-by: Puranjay Mohan <puranjay12@gmail.com> Message-ID: <20240311122722.86232-1-puranjay12@gmail.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-03-12bpf: Add x86-64 JIT support for bpf_addr_space_cast instruction.Alexei Starovoitov1-0/+5
LLVM generates bpf_addr_space_cast instruction while translating pointers between native (zero) address space and __attribute__((address_space(N))). The addr_space=1 is reserved as bpf_arena address space. rY = addr_space_cast(rX, 0, 1) is processed by the verifier and converted to normal 32-bit move: wX = wY rY = addr_space_cast(rX, 1, 0) has to be converted by JIT: aux_reg = upper_32_bits of arena->user_vm_start aux_reg <<= 32 wX = wY // clear upper 32 bits of dst register if (wX) // if not zero add upper bits of user_vm_start wX |= aux_reg JIT can do it more efficiently: mov dst_reg32, src_reg32 // 32-bit move shl dst_reg, 32 or dst_reg, user_vm_start rol dst_reg, 32 xor r11, r11 test dst_reg32, dst_reg32 // check if lower 32-bit are zero cmove r11, dst_reg // if so, set dst_reg to zero // Intel swapped src/dst register encoding in CMOVcc Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Eduard Zingerman <eddyz87@gmail.com> Link: https://lore.kernel.org/bpf/20240308010812.89848-5-alexei.starovoitov@gmail.com
2024-03-12bpf: Introduce bpf_arena.Alexei Starovoitov1-0/+11
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
2024-03-08bpf: Tell bpf programs kernel's PAGE_SIZEAlexei Starovoitov1-1/+6
vmlinux BTF includes all kernel enums. Add __PAGE_SIZE = PAGE_SIZE enum, so that bpf programs that include vmlinux.h can easily access it. Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/r/20240307031228.42896-7-alexei.starovoitov@gmail.com Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2024-03-07bpf: Introduce may_goto instructionAlexei Starovoitov1-0/+1
Introduce may_goto instruction that from the verifier pov is similar to open coded iterators bpf_for()/bpf_repeat() and bpf_loop() helper, but it doesn't iterate any objects. In assembly 'may_goto' is a nop most of the time until bpf runtime has to terminate the program for whatever reason. In the current implementation may_goto has a hidden counter, but other mechanisms can be used. For programs written in C the later patch introduces 'cond_break' macro that combines 'may_goto' with 'break' statement and has similar semantics: cond_break is a nop until bpf runtime has to break out of this loop. It can be used in any normal "for" or "while" loop, like for (i = zero; i < cnt; cond_break, i++) { The verifier recognizes that may_goto is used in the program, reserves additional 8 bytes of stack, initializes them in subprog prologue, and replaces may_goto instruction with: aux_reg = *(u64 *)(fp - 40) if aux_reg == 0 goto pc+off aux_reg -= 1 *(u64 *)(fp - 40) = aux_reg may_goto instruction can be used by LLVM to implement __builtin_memcpy, __builtin_strcmp. may_goto is not a full substitute for bpf_for() macro. bpf_for() doesn't have induction variable that verifiers sees, so 'i' in bpf_for(i, 0, 100) is seen as imprecise and bounded. But when the code is written as: for (i = 0; i < 100; cond_break, i++) the verifier see 'i' as precise constant zero, hence cond_break (aka may_goto) doesn't help to converge the loop. A static or global variable can be used as a workaround: static int zero = 0; for (i = zero; i < 100; cond_break, i++) // works! may_goto works well with arena pointers that don't need to be bounds checked on access. Load/store from arena returns imprecise unbounded scalar and loops with may_goto pass the verifier. Reserve new opcode BPF_JMP | BPF_JCOND for may_goto insn. JCOND stands for conditional pseudo jump. Since goto_or_nop insn was proposed, it may use the same opcode. may_goto vs goto_or_nop can be distinguished by src_reg: code = BPF_JMP | BPF_JCOND src_reg = 0 - may_goto src_reg = 1 - goto_or_nop Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Eduard Zingerman <eddyz87@gmail.com> Acked-by: John Fastabend <john.fastabend@gmail.com> Tested-by: John Fastabend <john.fastabend@gmail.com> Link: https://lore.kernel.org/bpf/20240306031929.42666-2-alexei.starovoitov@gmail.com
2024-01-25bpf: Consistently use BPF token throughout BPF verifier logicAndrii Nakryiko1-1/+1
Remove remaining direct queries to perfmon_capable() and bpf_capable() in BPF verifier logic and instead use BPF token (if available) to make decisions about privileges. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20240124022127.2379740-9-andrii@kernel.org
2024-01-25bpf: Add BPF token support to BPF_PROG_LOAD commandAndrii Nakryiko1-0/+1
Add basic support of BPF token to BPF_PROG_LOAD. BPF_F_TOKEN_FD flag should be set in prog_flags field when providing prog_token_fd. Wire through a set of allowed BPF program types and attach types, derived from BPF FS at BPF token creation time. Then make sure we perform bpf_token_capable() checks everywhere where it's relevant. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20240124022127.2379740-7-andrii@kernel.org
2024-01-24bpf: Support inlining bpf_kptr_xchg() helperHou Tao1-0/+10
The motivation of inlining bpf_kptr_xchg() comes from the performance profiling of bpf memory allocator benchmark. The benchmark uses bpf_kptr_xchg() to stash the allocated objects and to pop the stashed objects for free. After inling bpf_kptr_xchg(), the performance for object free on 8-CPUs VM increases about 2%~10%. The inline also has downside: both the kasan and kcsan checks on the pointer will be unavailable. bpf_kptr_xchg() can be inlined by converting the calling of bpf_kptr_xchg() into an atomic_xchg() instruction. But the conversion depends on two conditions: 1) JIT backend supports atomic_xchg() on pointer-sized word 2) For the specific arch, the implementation of xchg is the same as atomic_xchg() on pointer-sized words. It seems most 64-bit JIT backends satisfies these two conditions. But as a precaution, defining a weak function bpf_jit_supports_ptr_xchg() to state whether such conversion is safe and only supporting inline for 64-bit host. For x86-64, it supports BPF_XCHG atomic operation and both xchg() and atomic_xchg() use arch_xchg() to implement the exchange, so enabling the inline of bpf_kptr_xchg() on x86-64 first. Reviewed-by: Eduard Zingerman <eddyz87@gmail.com> Signed-off-by: Hou Tao <houtao1@huawei.com> Link: https://lore.kernel.org/r/20240105104819.3916743-2-houtao@huaweicloud.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-12-19Revert BPF token-related functionalityAndrii Nakryiko1-2/+1
This patch includes the following revert (one conflicting BPF FS patch and three token patch sets, represented by merge commits): - revert 0f5d5454c723 "Merge branch 'bpf-fs-mount-options-parsing-follow-ups'"; - revert 750e785796bb "bpf: Support uid and gid when mounting bpffs"; - revert 733763285acf "Merge branch 'bpf-token-support-in-libbpf-s-bpf-object'"; - revert c35919dcce28 "Merge branch 'bpf-token-and-bpf-fs-based-delegation'". Link: https://lore.kernel.org/bpf/CAHk-=wg7JuFYwGy=GOMbRCtOL+jwSQsdUaBsRWkDVYbxipbM5A@mail.gmail.com Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
2023-12-19Merge tag 'for-netdev' of ↵Jakub Kicinski1-12/+41
https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next Alexei Starovoitov says: ==================== pull-request: bpf-next 2023-12-18 This PR is larger than usual and contains changes in various parts of the kernel. The main changes are: 1) Fix kCFI bugs in BPF, from Peter Zijlstra. End result: all forms of indirect calls from BPF into kernel and from kernel into BPF work with CFI enabled. This allows BPF to work with CONFIG_FINEIBT=y. 2) Introduce BPF token object, from Andrii Nakryiko. It adds an ability to delegate a subset of BPF features from privileged daemon (e.g., systemd) through special mount options for userns-bound BPF FS to a trusted unprivileged application. The design accommodates suggestions from Christian Brauner and Paul Moore. Example: $ sudo mkdir -p /sys/fs/bpf/token $ sudo mount -t bpf bpffs /sys/fs/bpf/token \ -o delegate_cmds=prog_load:MAP_CREATE \ -o delegate_progs=kprobe \ -o delegate_attachs=xdp 3) Various verifier improvements and fixes, from Andrii Nakryiko, Andrei Matei. - Complete precision tracking support for register spills - Fix verification of possibly-zero-sized stack accesses - Fix access to uninit stack slots - Track aligned STACK_ZERO cases as imprecise spilled registers. It improves the verifier "instructions processed" metric from single digit to 50-60% for some programs. - Fix verifier retval logic 4) Support for VLAN tag in XDP hints, from Larysa Zaremba. 5) Allocate BPF trampoline via bpf_prog_pack mechanism, from Song Liu. End result: better memory utilization and lower I$ miss for calls to BPF via BPF trampoline. 6) Fix race between BPF prog accessing inner map and parallel delete, from Hou Tao. 7) Add bpf_xdp_get_xfrm_state() kfunc, from Daniel Xu. It allows BPF interact with IPSEC infra. The intent is to support software RSS (via XDP) for the upcoming ipsec pcpu work. Experiments on AWS demonstrate single tunnel pcpu ipsec reaching line rate on 100G ENA nics. 8) Expand bpf_cgrp_storage to support cgroup1 non-attach, from Yafang Shao. 9) BPF file verification via fsverity, from Song Liu. It allows BPF progs get fsverity digest. * tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (164 commits) bpf: Ensure precise is reset to false in __mark_reg_const_zero() selftests/bpf: Add more uprobe multi fail tests bpf: Fail uprobe multi link with negative offset selftests/bpf: Test the release of map btf s390/bpf: Fix indirect trampoline generation selftests/bpf: Temporarily disable dummy_struct_ops test on s390 x86/cfi,bpf: Fix bpf_exception_cb() signature bpf: Fix dtor CFI cfi: Add CFI_NOSEAL() x86/cfi,bpf: Fix bpf_struct_ops CFI x86/cfi,bpf: Fix bpf_callback_t CFI x86/cfi,bpf: Fix BPF JIT call cfi: Flip headers selftests/bpf: Add test for abnormal cnt during multi-kprobe attachment selftests/bpf: Don't use libbpf_get_error() in kprobe_multi_test selftests/bpf: Add test for abnormal cnt during multi-uprobe attachment bpf: Limit the number of kprobes when attaching program to multiple kprobes bpf: Limit the number of uprobes when attaching program to multiple uprobes bpf: xdp: Register generic_kfunc_set with XDP programs selftests/bpf: utilize string values for delegate_xxx mount options ... ==================== Link: https://lore.kernel.org/r/20231219000520.34178-1-alexei.starovoitov@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-12-16x86/cfi,bpf: Fix BPF JIT callPeter Zijlstra1-0/+25
The current BPF call convention is __nocfi, except when it calls !JIT things, then it calls regular C functions. It so happens that with FineIBT the __nocfi and C calling conventions are incompatible. Specifically __nocfi will call at func+0, while FineIBT will have endbr-poison there, which is not a valid indirect target. Causing #CP. Notably this only triggers on IBT enabled hardware, which is probably why this hasn't been reported (also, most people will have JIT on anyway). Implement proper CFI prologues for the BPF JIT codegen and drop __nocfi for x86. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20231215092707.345270396@infradead.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-12-07bpf: Let bpf_prog_pack_free handle any pointerSong Liu1-11/+10
Currently, bpf_prog_pack_free only can only free pointer to struct bpf_binary_header, which is not flexible. Add a size argument to bpf_prog_pack_free so that it can handle any pointer. 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 Reviewed-by: Björn Töpel <bjorn@rivosinc.com> Acked-by: Jiri Olsa <jolsa@kernel.org> Link: https://lore.kernel.org/r/20231206224054.492250-2-song@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-12-06bpf: consistently use BPF token throughout BPF verifier logicAndrii Nakryiko1-1/+1
Remove remaining direct queries to perfmon_capable() and bpf_capable() in BPF verifier logic and instead use BPF token (if available) to make decisions about privileges. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20231130185229.2688956-9-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-12-06bpf: add BPF token support to BPF_PROG_LOAD commandAndrii Nakryiko1-0/+1
Add basic support of BPF token to BPF_PROG_LOAD. Wire through a set of allowed BPF program types and attach types, derived from BPF FS at BPF token creation time. Then make sure we perform bpf_token_capable() checks everywhere where it's relevant. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20231130185229.2688956-7-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-12-05bpf: Optimize the free of inner mapHou Tao1-0/+4
When removing the inner map from the outer map, the inner map will be freed after one RCU grace period and one RCU tasks trace grace period, so it is certain that the bpf program, which may access the inner map, has exited before the inner map is freed. However there is no need to wait for one RCU tasks trace grace period if the outer map is only accessed by non-sleepable program. So adding sleepable_refcnt in bpf_map and increasing sleepable_refcnt when adding the outer map into env->used_maps for sleepable program. Although the max number of bpf program is INT_MAX - 1, the number of bpf programs which are being loaded may be greater than INT_MAX, so using atomic64_t instead of atomic_t for sleepable_refcnt. When removing the inner map from the outer map, using sleepable_refcnt to decide whether or not a RCU tasks trace grace period is needed before freeing the inner map. Signed-off-by: Hou Tao <houtao1@huawei.com> Link: https://lore.kernel.org/r/20231204140425.1480317-6-houtao@huaweicloud.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-12-02bpf: Fix a verifier bug due to incorrect branch offset comparison with cpu=v4Yonghong Song1-4/+8
Bpf cpu=v4 support is introduced in [1] and Commit 4cd58e9af8b9 ("bpf: Support new 32bit offset jmp instruction") added support for new 32bit offset jmp instruction. Unfortunately, in function bpf_adj_delta_to_off(), for new branch insn with 32bit offset, the offset (plus/minor a small delta) compares to 16-bit offset bound [S16_MIN, S16_MAX], which caused the following verification failure: $ ./test_progs-cpuv4 -t verif_scale_pyperf180 ... insn 10 cannot be patched due to 16-bit range ... libbpf: failed to load object 'pyperf180.bpf.o' scale_test:FAIL:expect_success unexpected error: -12 (errno 12) #405 verif_scale_pyperf180:FAIL Note that due to recent llvm18 development, the patch [2] (already applied in bpf-next) needs to be applied to bpf tree for testing purpose. The fix is rather simple. For 32bit offset branch insn, the adjusted offset compares to [S32_MIN, S32_MAX] and then verification succeeded. [1] https://lore.kernel.org/all/20230728011143.3710005-1-yonghong.song@linux.dev [2] https://lore.kernel.org/bpf/20231110193644.3130906-1-yonghong.song@linux.dev Fixes: 4cd58e9af8b9 ("bpf: Support new 32bit offset jmp instruction") Signed-off-by: Yonghong Song <yonghong.song@linux.dev> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20231201024640.3417057-1-yonghong.song@linux.dev
2023-11-15bpf: Do not allocate percpu memory at init stageYonghong Song1-5/+3
Kirill Shutemov reported significant percpu memory consumption increase after booting in 288-cpu VM ([1]) due to commit 41a5db8d8161 ("bpf: Add support for non-fix-size percpu mem allocation"). The percpu memory consumption is increased from 111MB to 969MB. The number is from /proc/meminfo. I tried to reproduce the issue with my local VM which at most supports upto 255 cpus. With 252 cpus, without the above commit, the percpu memory consumption immediately after boot is 57MB while with the above commit the percpu memory consumption is 231MB. This is not good since so far percpu memory from bpf memory allocator is not widely used yet. Let us change pre-allocation in init stage to on-demand allocation when verifier detects there is a need of percpu memory for bpf program. With this change, percpu memory consumption after boot can be reduced signicantly. [1] https://lore.kernel.org/lkml/20231109154934.4saimljtqx625l3v@box.shutemov.name/ Fixes: 41a5db8d8161 ("bpf: Add support for non-fix-size percpu mem allocation") Reported-and-tested-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Yonghong Song <yonghong.song@linux.dev> Acked-by: Hou Tao <houtao1@huawei.com> Link: https://lore.kernel.org/r/20231111013928.948838-1-yonghong.song@linux.dev Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-09-17Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-nextDavid S. Miller1-11/+26
Alexei Starovoitov says: ==================== The following pull-request contains BPF updates for your *net-next* tree. We've added 73 non-merge commits during the last 9 day(s) which contain a total of 79 files changed, 5275 insertions(+), 600 deletions(-). The main changes are: 1) Basic BTF validation in libbpf, from Andrii Nakryiko. 2) bpf_assert(), bpf_throw(), exceptions in bpf progs, from Kumar Kartikeya Dwivedi. 3) next_thread cleanups, from Oleg Nesterov. 4) Add mcpu=v4 support to arm32, from Puranjay Mohan. 5) Add support for __percpu pointers in bpf progs, from Yonghong Song. 6) Fix bpf tailcall interaction with bpf trampoline, from Leon Hwang. 7) Raise irq_work in bpf_mem_alloc while irqs are disabled to improve refill probabablity, from Hou Tao. Please consider pulling these changes from: git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git Thanks a lot! Also thanks to reporters, reviewers and testers of commits in this pull-request: Alan Maguire, Andrey Konovalov, Dave Marchevsky, "Eric W. Biederman", Jiri Olsa, Maciej Fijalkowski, Quentin Monnet, Russell King (Oracle), Song Liu, Stanislav Fomichev, Yonghong Song ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2023-09-16bpf: Detect IP == ksym.end as part of BPF programKumar Kartikeya Dwivedi1-1/+5
Now that bpf_throw kfunc is the first such call instruction that has noreturn semantics within the verifier, this also kicks in dead code elimination in unprecedented ways. For one, any instruction following a bpf_throw call will never be marked as seen. Moreover, if a callchain ends up throwing, any instructions after the call instruction to the eventually throwing subprog in callers will also never be marked as seen. The tempting way to fix this would be to emit extra 'int3' instructions which bump the jited_len of a program, and ensure that during runtime when a program throws, we can discover its boundaries even if the call instruction to bpf_throw (or to subprogs that always throw) is emitted as the final instruction in the program. An example of such a program would be this: do_something(): ... r0 = 0 exit foo(): r1 = 0 call bpf_throw r0 = 0 exit bar(cond): if r1 != 0 goto pc+2 call do_something exit call foo r0 = 0 // Never seen by verifier exit // main(ctx): r1 = ... call bar r0 = 0 exit Here, if we do end up throwing, the stacktrace would be the following: bpf_throw foo bar main In bar, the final instruction emitted will be the call to foo, as such, the return address will be the subsequent instruction (which the JIT emits as int3 on x86). This will end up lying outside the jited_len of the program, thus, when unwinding, we will fail to discover the return address as belonging to any program and end up in a panic due to the unreliable stack unwinding of BPF programs that we never expect. To remedy this case, make bpf_prog_ksym_find treat IP == ksym.end as part of the BPF program, so that is_bpf_text_address returns true when such a case occurs, and we are able to unwind reliably when the final instruction ends up being a call instruction. Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Link: https://lore.kernel.org/r/20230912233214.1518551-12-memxor@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-09-16bpf: Implement BPF exceptionsKumar Kartikeya Dwivedi1-1/+1
This patch implements BPF exceptions, and introduces a bpf_throw kfunc to allow programs to throw exceptions during their execution at runtime. A bpf_throw invocation is treated as an immediate termination of the program, returning back to its caller within the kernel, unwinding all stack frames. This allows the program to simplify its implementation, by testing for runtime conditions which the verifier has no visibility into, and assert that they are true. In case they are not, the program can simply throw an exception from the other branch. BPF exceptions are explicitly *NOT* an unlikely slowpath error handling primitive, and this objective has guided design choices of the implementation of the them within the kernel (with the bulk of the cost for unwinding the stack offloaded to the bpf_throw kfunc). The implementation of this mechanism requires use of add_hidden_subprog mechanism introduced in the previous patch, which generates a couple of instructions to move R1 to R0 and exit. The JIT then rewrites the prologue of this subprog to take the stack pointer and frame pointer as inputs and reset the stack frame, popping all callee-saved registers saved by the main subprog. The bpf_throw function then walks the stack at runtime, and invokes this exception subprog with the stack and frame pointers as parameters. Reviewers must take note that currently the main program is made to save all callee-saved registers on x86_64 during entry into the program. This is because we must do an equivalent of a lightweight context switch when unwinding the stack, therefore we need the callee-saved registers of the caller of the BPF program to be able to return with a sane state. Note that we have to additionally handle r12, even though it is not used by the program, because when throwing the exception the program makes an entry into the kernel which could clobber r12 after saving it on the stack. To be able to preserve the value we received on program entry, we push r12 and restore it from the generated subprogram when unwinding the stack. For now, bpf_throw invocation fails when lingering resources or locks exist in that path of the program. In a future followup, bpf_throw will be extended to perform frame-by-frame unwinding to release lingering resources for each stack frame, removing this limitation. Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Link: https://lore.kernel.org/r/20230912233214.1518551-5-memxor@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-09-16bpf: Implement support for adding hidden subprogsKumar Kartikeya Dwivedi1-6/+6
Introduce support in the verifier for generating a subprogram and include it as part of a BPF program dynamically after the do_check phase is complete. The first user will be the next patch which generates default exception callbacks if none are set for the program. The phase of invocation will be do_misc_fixups. Note that this is an internal verifier function, and should be used with instruction blocks which uphold the invariants stated in check_subprogs. Since these subprogs are always appended to the end of the instruction sequence of the program, it becomes relatively inexpensive to do the related adjustments to the subprog_info of the program. Only the fake exit subprogram is shifted forward, making room for our new subprog. This is useful to insert a new subprogram, get it JITed, and obtain its function pointer. The next patch will use this functionality to insert a default exception callback which will be invoked after unwinding the stack. Note that these added subprograms are invisible to userspace, and never reported in BPF_OBJ_GET_INFO_BY_ID etc. For now, only a single subprogram is supported, but more can be easily supported in the future. To this end, two function counts are introduced now, the existing func_cnt, and real_func_cnt, the latter including hidden programs. This allows us to conver the JIT code to use the real_func_cnt for management of resources while syscall path continues working with existing func_cnt. Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Link: https://lore.kernel.org/r/20230912233214.1518551-4-memxor@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-09-16arch/x86: Implement arch_bpf_stack_walkKumar Kartikeya Dwivedi1-0/+9
The plumbing for offline unwinding when we throw an exception in programs would require walking the stack, hence introduce a new arch_bpf_stack_walk function. This is provided when the JIT supports exceptions, i.e. bpf_jit_supports_exceptions is true. The arch-specific code is really minimal, hence it should be straightforward to extend this support to other architectures as well, as it reuses the logic of arch_stack_walk, but allowing access to unwind_state data. Once the stack pointer and frame pointer are known for the main subprog during the unwinding, we know the stack layout and location of any callee-saved registers which must be restored before we return back to the kernel. This handling will be added in the subsequent patches. Note that while we primarily unwind through BPF frames, which are effectively CONFIG_UNWINDER_FRAME_POINTER, we still need one of this or CONFIG_UNWINDER_ORC to be able to unwind through the bpf_throw frame from which we begin walking the stack. We also require both sp and bp (stack and frame pointers) from the unwind_state structure, which are only available when one of these two options are enabled. Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Link: https://lore.kernel.org/r/20230912233214.1518551-3-memxor@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-09-08bpf: Add support for non-fix-size percpu mem allocationYonghong Song1-3/+5
This is needed for later percpu mem allocation when the allocation is done by bpf program. For such cases, a global bpf_global_percpu_ma is added where a flexible allocation size is needed. Signed-off-by: Yonghong Song <yonghong.song@linux.dev> Link: https://lore.kernel.org/r/20230827152734.1995725-1-yonghong.song@linux.dev Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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>
2023-08-03bpf: fix bpf_probe_read_kernel prototype mismatchArnd Bergmann1-9/+3
bpf_probe_read_kernel() has a __weak definition in core.c and another definition with an incompatible prototype in kernel/trace/bpf_trace.c, when CONFIG_BPF_EVENTS is enabled. Since the two are incompatible, there cannot be a shared declaration in a header file, but the lack of a prototype causes a W=1 warning: kernel/bpf/core.c:1638:12: error: no previous prototype for 'bpf_probe_read_kernel' [-Werror=missing-prototypes] On 32-bit architectures, the local prototype u64 __weak bpf_probe_read_kernel(void *dst, u32 size, const void *unsafe_ptr) passes arguments in other registers as the one in bpf_trace.c BPF_CALL_3(bpf_probe_read_kernel, void *, dst, u32, size, const void *, unsafe_ptr) which uses 64-bit arguments in pairs of registers. As both versions of the function are fairly simple and only really differ in one line, just move them into a header file as an inline function that does not add any overhead for the bpf_trace.c callers and actually avoids a function call for the other one. Cc: stable@vger.kernel.org Link: https://lore.kernel.org/all/ac25cb0f-b804-1649-3afb-1dc6138c2716@iogearbox.net/ Signed-off-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Yonghong Song <yonghong.song@linux.dev> Link: https://lore.kernel.org/r/20230801111449.185301-1-arnd@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-07-28bpf: Fix compilation warning with -WparenthesesYonghong Song1-2/+2
The kernel test robot reported compilation warnings when -Wparentheses is added to KBUILD_CFLAGS with gcc compiler. The following is the error message: .../bpf-next/kernel/bpf/verifier.c: In function ‘coerce_reg_to_size_sx’: .../bpf-next/kernel/bpf/verifier.c:5901:14: error: suggest parentheses around comparison in operand of ‘==’ [-Werror=parentheses] if (s64_max >= 0 == s64_min >= 0) { ~~~~~~~~^~~~ .../bpf-next/kernel/bpf/verifier.c: In function ‘coerce_subreg_to_size_sx’: .../bpf-next/kernel/bpf/verifier.c:5965:14: error: suggest parentheses around comparison in operand of ‘==’ [-Werror=parentheses] if (s32_min >= 0 == s32_max >= 0) { ~~~~~~~~^~~~ To fix the issue, add proper parentheses for the above '>=' condition to silence the warning/error. I tried a few clang compilers like clang16 and clang18 and they do not emit such warnings with -Wparentheses. Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202307281133.wi0c4SqG-lkp@intel.com/ Signed-off-by: Yonghong Song <yonghong.song@linux.dev> Acked-by: Jiri Olsa <jolsa@kernel.org> Link: https://lore.kernel.org/r/20230728055740.2284534-1-yonghong.song@linux.dev Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-07-28bpf: Support new 32bit offset jmp instructionYonghong Song1-3/+16
Add interpreter/jit/verifier support for 32bit offset jmp instruction. If a conditional jmp instruction needs more than 16bit offset, it can be simulated with a conditional jmp + a 32bit jmp insn. Acked-by: Eduard Zingerman <eddyz87@gmail.com> Signed-off-by: Yonghong Song <yonghong.song@linux.dev> Link: https://lore.kernel.org/r/20230728011231.3716103-1-yonghong.song@linux.dev Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-07-28bpf: Fix jit blinding with new sdiv/smov insnsYonghong Song1-2/+2
Handle new insns properly in bpf_jit_blind_insn() function. Acked-by: Eduard Zingerman <eddyz87@gmail.com> Signed-off-by: Yonghong Song <yonghong.song@linux.dev> Link: https://lore.kernel.org/r/20230728011225.3715812-1-yonghong.song@linux.dev Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-07-28bpf: Support new signed div/mod instructions.Yonghong Song1-16/+94
Add interpreter/jit support for new signed div/mod insns. The new signed div/mod instructions are encoded with unsigned div/mod instructions plus insn->off == 1. Also add basic verifier support to ensure new insns get accepted. Acked-by: Eduard Zingerman <eddyz87@gmail.com> Signed-off-by: Yonghong Song <yonghong.song@linux.dev> Link: https://lore.kernel.org/r/20230728011219.3714605-1-yonghong.song@linux.dev Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-07-28bpf: Support new unconditional bswap instructionYonghong Song1-0/+14
The existing 'be' and 'le' insns will do conditional bswap depends on host endianness. This patch implements unconditional bswap insns. Acked-by: Eduard Zingerman <eddyz87@gmail.com> Signed-off-by: Yonghong Song <yonghong.song@linux.dev> Link: https://lore.kernel.org/r/20230728011213.3712808-1-yonghong.song@linux.dev Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-07-28bpf: Support new sign-extension mov insnsYonghong Song1-2/+26
Add interpreter/jit support for new sign-extension mov insns. The original 'MOV' insn is extended to support reg-to-reg signed version for both ALU and ALU64 operations. For ALU mode, the insn->off value of 8 or 16 indicates sign-extension from 8- or 16-bit value to 32-bit value. For ALU64 mode, the insn->off value of 8/16/32 indicates sign-extension from 8-, 16- or 32-bit value to 64-bit value. Acked-by: Eduard Zingerman <eddyz87@gmail.com> Signed-off-by: Yonghong Song <yonghong.song@linux.dev> Link: https://lore.kernel.org/r/20230728011202.3712300-1-yonghong.song@linux.dev Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-07-28bpf: Support new sign-extension load insnsYonghong Song1-0/+21
Add interpreter/jit support for new sign-extension load insns which adds a new mode (BPF_MEMSX). Also add verifier support to recognize these insns and to do proper verification with new insns. In verifier, besides to deduce proper bounds for the dst_reg, probed memory access is also properly handled. Acked-by: Eduard Zingerman <eddyz87@gmail.com> Signed-off-by: Yonghong Song <yonghong.song@linux.dev> Link: https://lore.kernel.org/r/20230728011156.3711870-1-yonghong.song@linux.dev Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-06-12bpf: Hide unused bpf_patch_call_argsArnd Bergmann1-3/+5
This function is only used when CONFIG_BPF_JIT_ALWAYS_ON is disabled, but CONFIG_BPF_SYSCALL is enabled. When both are turned off, the prototype is missing but the unused function is still compiled, as seen from this W=1 warning: [...] kernel/bpf/core.c:2075:6: error: no previous prototype for 'bpf_patch_call_args' [-Werror=missing-prototypes] [...] Add a matching #ifdef for the definition to leave it out. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20230602135128.1498362-1-arnd@kernel.org
2023-04-14bpf: Support 64-bit pointers to kfuncsIlya Leoshkevich1-0/+11
test_ksyms_module fails to emit a kfunc call targeting a module on s390x, because the verifier stores the difference between kfunc address and __bpf_call_base in bpf_insn.imm, which is s32, and modules are roughly (1 << 42) bytes away from the kernel on s390x. Fix by keeping BTF id in bpf_insn.imm for BPF_PSEUDO_KFUNC_CALLs, and storing the absolute address in bpf_kfunc_desc. Introduce bpf_jit_supports_far_kfunc_call() in order to limit this new behavior to the s390x JIT. Otherwise other JITs need to be modified, which is not desired. Introduce bpf_get_kfunc_addr() instead of exposing both find_kfunc_desc() and struct bpf_kfunc_desc. In addition to sorting kfuncs by imm, also sort them by offset, in order to handle conflicting imms from different modules. Do this on all architectures in order to simplify code. Factor out resolving specialized kfuncs (XPD and dynptr) from fixup_kfunc_call(). This was required in the first place, because fixup_kfunc_call() uses find_kfunc_desc(), which returns a const pointer, so it's not possible to modify kfunc addr without stripping const, which is not nice. It also removes repetition of code like: if (bpf_jit_supports_far_kfunc_call()) desc->addr = func; else insn->imm = BPF_CALL_IMM(func); and separates kfunc_desc_tab fixups from kfunc_call fixups. Suggested-by: Jiri Olsa <olsajiri@gmail.com> Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Acked-by: Jiri Olsa <jolsa@kernel.org> Link: https://lore.kernel.org/r/20230412230632.885985-1-iii@linux.ibm.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-03-21bpf: Adjust insufficient default bpf_jit_limitDaniel Borkmann1-1/+1
We've seen recent AWS EKS (Kubernetes) user reports like the following: After upgrading EKS nodes from v20230203 to v20230217 on our 1.24 EKS clusters after a few days a number of the nodes have containers stuck in ContainerCreating state or liveness/readiness probes reporting the following error: Readiness probe errored: rpc error: code = Unknown desc = failed to exec in container: failed to start exec "4a11039f730203ffc003b7[...]": OCI runtime exec failed: exec failed: unable to start container process: unable to init seccomp: error loading seccomp filter into kernel: error loading seccomp filter: errno 524: unknown However, we had not been seeing this issue on previous AMIs and it only started to occur on v20230217 (following the upgrade from kernel 5.4 to 5.10) with no other changes to the underlying cluster or workloads. We tried the suggestions from that issue (sysctl net.core.bpf_jit_limit=452534528) which helped to immediately allow containers to be created and probes to execute but after approximately a day the issue returned and the value returned by cat /proc/vmallocinfo | grep bpf_jit | awk '{s+=$2} END {print s}' was steadily increasing. I tested bpf tree to observe bpf_jit_charge_modmem, bpf_jit_uncharge_modmem their sizes passed in as well as bpf_jit_current under tcpdump BPF filter, seccomp BPF and native (e)BPF programs, and the behavior all looks sane and expected, that is nothing "leaking" from an upstream perspective. The bpf_jit_limit knob was originally added in order to avoid a situation where unprivileged applications loading BPF programs (e.g. seccomp BPF policies) consuming all the module memory space via BPF JIT such that loading of kernel modules would be prevented. The default limit was defined back in 2018 and while good enough back then, we are generally seeing far more BPF consumers today. Adjust the limit for the BPF JIT pool from originally 1/4 to now 1/2 of the module memory space to better reflect today's needs and avoid more users running into potentially hard to debug issues. Fixes: fdadd04931c2 ("bpf: fix bpf_jit_limit knob for PAGE_SIZE >= 64K") Reported-by: Stephen Haynes <sh@synk.net> Reported-by: Lefteris Alexakis <lefteris.alexakis@kpn.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://github.com/awslabs/amazon-eks-ami/issues/1179 Link: https://github.com/awslabs/amazon-eks-ami/issues/1219 Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://lore.kernel.org/r/20230320143725.8394-1-daniel@iogearbox.net Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-02-22bpf: add missing header file includeLinus Torvalds1-0/+1
Commit 74e19ef0ff80 ("uaccess: Add speculation barrier to copy_from_user()") built fine on x86-64 and arm64, and that's the extent of my local build testing. It turns out those got the <linux/nospec.h> include incidentally through other header files (<linux/kvm_host.h> in particular), but that was not true of other architectures, resulting in build errors kernel/bpf/core.c: In function ‘___bpf_prog_run’: kernel/bpf/core.c:1913:3: error: implicit declaration of function ‘barrier_nospec’ so just make sure to explicitly include the proper <linux/nospec.h> header file to make everybody see it. Fixes: 74e19ef0ff80 ("uaccess: Add speculation barrier to copy_from_user()") Reported-by: kernel test robot <lkp@intel.com> Reported-by: Viresh Kumar <viresh.kumar@linaro.org> Reported-by: Huacai Chen <chenhuacai@loongson.cn> Tested-by: Geert Uytterhoeven <geert@linux-m68k.org> Tested-by: Dave Hansen <dave.hansen@linux.intel.com> Acked-by: Alexei Starovoitov <alexei.starovoitov@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2023-02-22Merge tag 'net-next-6.3' of ↵Linus Torvalds1-8/+17
git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next Pull networking updates from Jakub Kicinski: "Core: - Add dedicated kmem_cache for typical/small skb->head, avoid having to access struct page at kfree time, and improve memory use. - Introduce sysctl to set default RPS configuration for new netdevs. - Define Netlink protocol specification format which can be used to describe messages used by each family and auto-generate parsers. Add tools for generating kernel data structures and uAPI headers. - Expose all net/core sysctls inside netns. - Remove 4s sleep in netpoll if carrier is instantly detected on boot. - Add configurable limit of MDB entries per port, and port-vlan. - Continue populating drop reasons throughout the stack. - Retire a handful of legacy Qdiscs and classifiers. Protocols: - Support IPv4 big TCP (TSO frames larger than 64kB). - Add IP_LOCAL_PORT_RANGE socket option, to control local port range on socket by socket basis. - Track and report in procfs number of MPTCP sockets used. - Support mixing IPv4 and IPv6 flows in the in-kernel MPTCP path manager. - IPv6: don't check net.ipv6.route.max_size and rely on garbage collection to free memory (similarly to IPv4). - Support Penultimate Segment Pop (PSP) flavor in SRv6 (RFC8986). - ICMP: add per-rate limit counters. - Add support for user scanning requests in ieee802154. - Remove static WEP support. - Support minimal Wi-Fi 7 Extremely High Throughput (EHT) rate reporting. - WiFi 7 EHT channel puncturing support (client & AP). BPF: - Add a rbtree data structure following the "next-gen data structure" precedent set by recently added linked list, that is, by using kfunc + kptr instead of adding a new BPF map type. - Expose XDP hints via kfuncs with initial support for RX hash and timestamp metadata. - Add BPF_F_NO_TUNNEL_KEY extension to bpf_skb_set_tunnel_key to better support decap on GRE tunnel devices not operating in collect metadata. - Improve x86 JIT's codegen for PROBE_MEM runtime error checks. - Remove the need for trace_printk_lock for bpf_trace_printk and bpf_trace_vprintk helpers. - Extend libbpf's bpf_tracing.h support for tracing arguments of kprobes/uprobes and syscall as a special case. - Significantly reduce the search time for module symbols by livepatch and BPF. - Enable cpumasks to be used as kptrs, which is useful for tracing programs tracking which tasks end up running on which CPUs in different time intervals. - Add support for BPF trampoline on s390x and riscv64. - Add capability to export the XDP features supported by the NIC. - Add __bpf_kfunc tag for marking kernel functions as kfuncs. - Add cgroup.memory=nobpf kernel parameter option to disable BPF memory accounting for container environments. Netfilter: - Remove the CLUSTERIP target. It has been marked as obsolete for years, and we still have WARN splats wrt races of the out-of-band /proc interface installed by this target. - Add 'destroy' commands to nf_tables. They are identical to the existing 'delete' commands, but do not return an error if the referenced object (set, chain, rule...) did not exist. Driver API: - Improve cpumask_local_spread() locality to help NICs set the right IRQ affinity on AMD platforms. - Separate C22 and C45 MDIO bus transactions more clearly. - Introduce new DCB table to control DSCP rewrite on egress. - Support configuration of Physical Layer Collision Avoidance (PLCA) Reconciliation Sublayer (RS) (802.3cg-2019). Modern version of shared medium Ethernet. - Support for MAC Merge layer (IEEE 802.3-2018 clause 99). Allowing preemption of low priority frames by high priority frames. - Add support for controlling MACSec offload using netlink SET. - Rework devlink instance refcounts to allow registration and de-registration under the instance lock. Split the code into multiple files, drop some of the unnecessarily granular locks and factor out common parts of netlink operation handling. - Add TX frame aggregation parameters (for USB drivers). - Add a new attr TCA_EXT_WARN_MSG to report TC (offload) warning messages with notifications for debug. - Allow offloading of UDP NEW connections via act_ct. - Add support for per action HW stats in TC. - Support hardware miss to TC action (continue processing in SW from a specific point in the action chain). - Warn if old Wireless Extension user space interface is used with modern cfg80211/mac80211 drivers. Do not support Wireless Extensions for Wi-Fi 7 devices at all. Everyone should switch to using nl80211 interface instead. - Improve the CAN bit timing configuration. Use extack to return error messages directly to user space, update the SJW handling, including the definition of a new default value that will benefit CAN-FD controllers, by increasing their oscillator tolerance. New hardware / drivers: - Ethernet: - nVidia BlueField-3 support (control traffic driver) - Ethernet support for imx93 SoCs - Motorcomm yt8531 gigabit Ethernet PHY - onsemi NCN26000 10BASE-T1S PHY (with support for PLCA) - Microchip LAN8841 PHY (incl. cable diagnostics and PTP) - Amlogic gxl MDIO mux - WiFi: - RealTek RTL8188EU (rtl8xxxu) - Qualcomm Wi-Fi 7 devices (ath12k) - CAN: - Renesas R-Car V4H Drivers: - Bluetooth: - Set Per Platform Antenna Gain (PPAG) for Intel controllers. - Ethernet NICs: - Intel (1G, igc): - support TSN / Qbv / packet scheduling features of i226 model - Intel (100G, ice): - use GNSS subsystem instead of TTY - multi-buffer XDP support - extend support for GPIO pins to E823 devices - nVidia/Mellanox: - update the shared buffer configuration on PFC commands - implement PTP adjphase function for HW offset control - TC support for Geneve and GRE with VF tunnel offload - more efficient crypto key management method - multi-port eswitch support - Netronome/Corigine: - add DCB IEEE support - support IPsec offloading for NFP3800 - Freescale/NXP (enetc): - support XDP_REDIRECT for XDP non-linear buffers - improve reconfig, avoid link flap and waiting for idle - support MAC Merge layer - Other NICs: - sfc/ef100: add basic devlink support for ef100 - ionic: rx_push mode operation (writing descriptors via MMIO) - bnxt: use the auxiliary bus abstraction for RDMA - r8169: disable ASPM and reset bus in case of tx timeout - cpsw: support QSGMII mode for J721e CPSW9G - cpts: support pulse-per-second output - ngbe: add an mdio bus driver - usbnet: optimize usbnet_bh() by avoiding unnecessary queuing - r8152: handle devices with FW with NCM support - amd-xgbe: support 10Mbps, 2.5GbE speeds and rx-adaptation - virtio-net: support multi buffer XDP - virtio/vsock: replace virtio_vsock_pkt with sk_buff - tsnep: XDP support - Ethernet high-speed switches: - nVidia/Mellanox (mlxsw): - add support for latency TLV (in FW control messages) - Microchip (sparx5): - separate explicit and implicit traffic forwarding rules, make the implicit rules always active - add support for egress DSCP rewrite - IS0 VCAP support (Ingress Classification) - IS2 VCAP filters (protos, L3 addrs, L4 ports, flags, ToS etc.) - ES2 VCAP support (Egress Access Control) - support for Per-Stream Filtering and Policing (802.1Q, 8.6.5.1) - Ethernet embedded switches: - Marvell (mv88e6xxx): - add MAB (port auth) offload support - enable PTP receive for mv88e6390 - NXP (ocelot): - support MAC Merge layer - support for the the vsc7512 internal copper phys - Microchip: - lan9303: convert to PHYLINK - lan966x: support TC flower filter statistics - lan937x: PTP support for KSZ9563/KSZ8563 and LAN937x - lan937x: support Credit Based Shaper configuration - ksz9477: support Energy Efficient Ethernet - other: - qca8k: convert to regmap read/write API, use bulk operations - rswitch: Improve TX timestamp accuracy - Intel WiFi (iwlwifi): - EHT (Wi-Fi 7) rate reporting - STEP equalizer support: transfer some STEP (connection to radio on platforms with integrated wifi) related parameters from the BIOS to the firmware. - Qualcomm 802.11ax WiFi (ath11k): - IPQ5018 support - Fine Timing Measurement (FTM) responder role support - channel 177 support - MediaTek WiFi (mt76): - per-PHY LED support - mt7996: EHT (Wi-Fi 7) support - Wireless Ethernet Dispatch (WED) reset support - switch to using page pool allocator - RealTek WiFi (rtw89): - support new version of Bluetooth co-existance - Mobile: - rmnet: support TX aggregation" * tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1872 commits) page_pool: add a comment explaining the fragment counter usage net: ethtool: fix __ethtool_dev_mm_supported() implementation ethtool: pse-pd: Fix double word in comments xsk: add linux/vmalloc.h to xsk.c sefltests: netdevsim: wait for devlink instance after netns removal selftest: fib_tests: Always cleanup before exit net/mlx5e: Align IPsec ASO result memory to be as required by hardware net/mlx5e: TC, Set CT miss to the specific ct action instance net/mlx5e: Rename CHAIN_TO_REG to MAPPED_OBJ_TO_REG net/mlx5: Refactor tc miss handling to a single function net/mlx5: Kconfig: Make tc offload depend on tc skb extension net/sched: flower: Support hardware miss to tc action net/sched: flower: Move filter handle initialization earlier net/sched: cls_api: Support hardware miss to tc action net/sched: Rename user cookie and act cookie sfc: fix builds without CONFIG_RTC_LIB sfc: clean up some inconsistent indentings net/mlx4_en: Introduce flexible array to silence overflow warning net: lan966x: Fix possible deadlock inside PTP net/ulp: Remove redundant ->clone() test in inet_clone_ulp(). ...
2023-02-22uaccess: Add speculation barrier to copy_from_user()Dave Hansen1-2/+0
The results of "access_ok()" can be mis-speculated. The result is that you can end speculatively: if (access_ok(from, size)) // Right here even for bad from/size combinations. On first glance, it would be ideal to just add a speculation barrier to "access_ok()" so that its results can never be mis-speculated. But there are lots of system calls just doing access_ok() via "copy_to_user()" and friends (example: fstat() and friends). Those are generally not problematic because they do not _consume_ data from userspace other than the pointer. They are also very quick and common system calls that should not be needlessly slowed down. "copy_from_user()" on the other hand uses a user-controller pointer and is frequently followed up with code that might affect caches. Take something like this: if (!copy_from_user(&kernelvar, uptr, size)) do_something_with(kernelvar); If userspace passes in an evil 'uptr' that *actually* points to a kernel addresses, and then do_something_with() has cache (or other) side-effects, it could allow userspace to infer kernel data values. Add a barrier to the common copy_from_user() code to prevent mis-speculated values which happen after the copy. Also add a stub for architectures that do not define barrier_nospec(). This makes the macro usable in generic code. Since the barrier is now usable in generic code, the x86 #ifdef in the BPF code can also go away. Reported-by: Jordy Zomer <jordyzomer@google.com> Suggested-by: Linus Torvalds <torvalds@linuxfoundation.org> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Daniel Borkmann <daniel@iogearbox.net> # BPF bits Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2023-02-11bpf: allow to disable bpf prog memory accountingYafang Shao1-6/+7
We can simply disable the bpf prog memory accouting by not setting the GFP_ACCOUNT. Signed-off-by: Yafang Shao <laoar.shao@gmail.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Roman Gushchin <roman.gushchin@linux.dev> Link: https://lore.kernel.org/r/20230210154734.4416-5-laoar.shao@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-01-23bpf: XDP metadata RX kfuncsStanislav Fomichev1-0/+8
Define a new kfunc set (xdp_metadata_kfunc_ids) which implements all possible XDP metatada kfuncs. Not all devices have to implement them. If kfunc is not supported by the target device, the default implementation is called instead. The verifier, at load time, replaces a call to the generic kfunc with a call to the per-device one. Per-device kfunc pointers are stored in separate struct xdp_metadata_ops. Cc: John Fastabend <john.fastabend@gmail.com> Cc: David Ahern <dsahern@gmail.com> Cc: Martin KaFai Lau <martin.lau@linux.dev> Cc: Jakub Kicinski <kuba@kernel.org> Cc: Willem de Bruijn <willemb@google.com> Cc: Jesper Dangaard Brouer <brouer@redhat.com> Cc: Anatoly Burakov <anatoly.burakov@intel.com> Cc: Alexander Lobakin <alexandr.lobakin@intel.com> Cc: Magnus Karlsson <magnus.karlsson@gmail.com> Cc: Maryam Tahhan <mtahhan@redhat.com> Cc: xdp-hints@xdp-project.net Cc: netdev@vger.kernel.org Signed-off-by: Stanislav Fomichev <sdf@google.com> Link: https://lore.kernel.org/r/20230119221536.3349901-8-sdf@google.com Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2023-01-23bpf: Introduce device-bound XDP programsStanislav Fomichev1-2/+2
New flag BPF_F_XDP_DEV_BOUND_ONLY plus all the infra to have a way to associate a netdev with a BPF program at load time. netdevsim checks are dropped in favor of generic check in dev_xdp_attach. Cc: John Fastabend <john.fastabend@gmail.com> Cc: David Ahern <dsahern@gmail.com> Cc: Martin KaFai Lau <martin.lau@linux.dev> Cc: Jakub Kicinski <kuba@kernel.org> Cc: Willem de Bruijn <willemb@google.com> Cc: Jesper Dangaard Brouer <brouer@redhat.com> Cc: Anatoly Burakov <anatoly.burakov@intel.com> Cc: Alexander Lobakin <alexandr.lobakin@intel.com> Cc: Magnus Karlsson <magnus.karlsson@gmail.com> Cc: Maryam Tahhan <mtahhan@redhat.com> Cc: xdp-hints@xdp-project.net Cc: netdev@vger.kernel.org Signed-off-by: Stanislav Fomichev <sdf@google.com> Link: https://lore.kernel.org/r/20230119221536.3349901-6-sdf@google.com Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2023-01-23bpf: Rename bpf_{prog,map}_is_dev_bound to is_offloadedStanislav Fomichev1-2/+2
BPF offloading infra will be reused to implement bound-but-not-offloaded bpf programs. Rename existing helpers for clarity. No functional changes. Cc: John Fastabend <john.fastabend@gmail.com> Cc: David Ahern <dsahern@gmail.com> Cc: Martin KaFai Lau <martin.lau@linux.dev> Cc: Willem de Bruijn <willemb@google.com> Cc: Jesper Dangaard Brouer <brouer@redhat.com> Cc: Anatoly Burakov <anatoly.burakov@intel.com> Cc: Alexander Lobakin <alexandr.lobakin@intel.com> Cc: Magnus Karlsson <magnus.karlsson@gmail.com> Cc: Maryam Tahhan <mtahhan@redhat.com> Cc: xdp-hints@xdp-project.net Cc: netdev@vger.kernel.org Reviewed-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Stanislav Fomichev <sdf@google.com> Link: https://lore.kernel.org/r/20230119221536.3349901-3-sdf@google.com Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2022-12-21Merge tag 'net-6.2-rc1' of ↵Linus Torvalds1-2/+3
git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net Pull networking fixes from Jakub Kicinski: "Including fixes from bpf, netfilter and can. Current release - regressions: - bpf: synchronize dispatcher update with bpf_dispatcher_xdp_func - rxrpc: - fix security setting propagation - fix null-deref in rxrpc_unuse_local() - fix switched parameters in peer tracing Current release - new code bugs: - rxrpc: - fix I/O thread startup getting skipped - fix locking issues in rxrpc_put_peer_locked() - fix I/O thread stop - fix uninitialised variable in rxperf server - fix the return value of rxrpc_new_incoming_call() - microchip: vcap: fix initialization of value and mask - nfp: fix unaligned io read of capabilities word Previous releases - regressions: - stop in-kernel socket users from corrupting socket's task_frag - stream: purge sk_error_queue in sk_stream_kill_queues() - openvswitch: fix flow lookup to use unmasked key - dsa: mv88e6xxx: avoid reg_lock deadlock in mv88e6xxx_setup_port() - devlink: - hold region lock when flushing snapshots - protect devlink dump by the instance lock Previous releases - always broken: - bpf: - prevent leak of lsm program after failed attach - resolve fext program type when checking map compatibility - skbuff: account for tail adjustment during pull operations - macsec: fix net device access prior to holding a lock - bonding: switch back when high prio link up - netfilter: flowtable: really fix NAT IPv6 offload - enetc: avoid buffer leaks on xdp_do_redirect() failure - unix: fix race in SOCK_SEQPACKET's unix_dgram_sendmsg() - dsa: microchip: remove IRQF_TRIGGER_FALLING in request_threaded_irq" * tag 'net-6.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (64 commits) net: fec: check the return value of build_skb() net: simplify sk_page_frag Treewide: Stop corrupting socket's task_frag net: Introduce sk_use_task_frag in struct sock. mctp: Remove device type check at unregister net: dsa: microchip: remove IRQF_TRIGGER_FALLING in request_threaded_irq can: kvaser_usb: hydra: help gcc-13 to figure out cmd_len can: flexcan: avoid unbalanced pm_runtime_enable warning Documentation: devlink: add missing toc entry for etas_es58x devlink doc mctp: serial: Fix starting value for frame check sequence nfp: fix unaligned io read of capabilities word net: stream: purge sk_error_queue in sk_stream_kill_queues() myri10ge: Fix an error handling path in myri10ge_probe() net: microchip: vcap: Fix initialization of value and mask rxrpc: Fix the return value of rxrpc_new_incoming_call() rxrpc: rxperf: Fix uninitialised variable rxrpc: Fix I/O thread stop rxrpc: Fix switched parameters in peer tracing rxrpc: Fix locking issues in rxrpc_put_peer_locked() rxrpc: Fix I/O thread startup getting skipped ...
2022-12-17Merge tag 'x86_mm_for_6.2_v2' of ↵Linus Torvalds1-4/+2
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 mm updates from Dave Hansen: "New Feature: - Randomize the per-cpu entry areas Cleanups: - Have CR3_ADDR_MASK use PHYSICAL_PAGE_MASK instead of open coding it - Move to "native" set_memory_rox() helper - Clean up pmd_get_atomic() and i386-PAE - Remove some unused page table size macros" * tag 'x86_mm_for_6.2_v2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (35 commits) x86/mm: Ensure forced page table splitting x86/kasan: Populate shadow for shared chunk of the CPU entry area x86/kasan: Add helpers to align shadow addresses up and down x86/kasan: Rename local CPU_ENTRY_AREA variables to shorten names x86/mm: Populate KASAN shadow for entire per-CPU range of CPU entry area x86/mm: Recompute physical address for every page of per-CPU CEA mapping x86/mm: Rename __change_page_attr_set_clr(.checkalias) x86/mm: Inhibit _PAGE_NX changes from cpa_process_alias() x86/mm: Untangle __change_page_attr_set_clr(.checkalias) x86/mm: Add a few comments x86/mm: Fix CR3_ADDR_MASK x86/mm: Remove P*D_PAGE_MASK and P*D_PAGE_SIZE macros mm: Convert __HAVE_ARCH_P..P_GET to the new style mm: Remove pointless barrier() after pmdp_get_lockless() x86/mm/pae: Get rid of set_64bit() x86_64: Remove pointless set_64bit() usage x86/mm/pae: Be consistent with pXXp_get_and_clear() x86/mm/pae: Use WRITE_ONCE() x86/mm/pae: Don't (ab)use atomic64 mm/gup: Fix the lockless PMD access ...
2022-12-15mm: Introduce set_memory_rox()Peter Zijlstra1-4/+2
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
2022-12-15bpf: Resolve fext program type when checking map compatibilityToke Høiland-Jørgensen1-2/+3
The bpf_prog_map_compatible() check makes sure that BPF program types are not mixed inside BPF map types that can contain programs (tail call maps, cpumaps and devmaps). It does this by setting the fields of the map->owner struct to the values of the first program being checked against, and rejecting any subsequent programs if the values don't match. One of the values being set in the map owner struct is the program type, and since the code did not resolve the prog type for fext programs, the map owner type would be set to PROG_TYPE_EXT and subsequent loading of programs of the target type into the map would fail. This bug is seen in particular for XDP programs that are loaded as PROG_TYPE_EXT using libxdp; these cannot insert programs into devmaps and cpumaps because the check fails as described above. Fix the bug by resolving the fext program type to its target program type as elsewhere in the verifier. v3: - Add Yonghong's ACK Fixes: f45d5b6ce2e8 ("bpf: generalise tail call map compatibility check") Acked-by: Yonghong Song <yhs@fb.com> Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com> Link: https://lore.kernel.org/r/20221214230254.790066-1-toke@redhat.com Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2022-12-14Merge tag 'net-next-6.2' of ↵Linus Torvalds1-1/+23
git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next Pull networking updates from Paolo Abeni: "Core: - Allow live renaming when an interface is up - Add retpoline wrappers for tc, improving considerably the performances of complex queue discipline configurations - Add inet drop monitor support - A few GRO performance improvements - Add infrastructure for atomic dev stats, addressing long standing data races - De-duplicate common code between OVS and conntrack offloading infrastructure - A bunch of UBSAN_BOUNDS/FORTIFY_SOURCE improvements - Netfilter: introduce packet parser for tunneled packets - Replace IPVS timer-based estimators with kthreads to scale up the workload with the number of available CPUs - Add the helper support for connection-tracking OVS offload BPF: - Support for user defined BPF objects: the use case is to allocate own objects, build own object hierarchies and use the building blocks to build own data structures flexibly, for example, linked lists in BPF - Make cgroup local storage available to non-cgroup attached BPF programs - Avoid unnecessary deadlock detection and failures wrt BPF task storage helpers - A relevant bunch of BPF verifier fixes and improvements - Veristat tool improvements to support custom filtering, sorting, and replay of results - Add LLVM disassembler as default library for dumping JITed code - Lots of new BPF documentation for various BPF maps - Add bpf_rcu_read_{,un}lock() support for sleepable programs - Add RCU grace period chaining to BPF to wait for the completion of access from both sleepable and non-sleepable BPF programs - Add support storing struct task_struct objects as kptrs in maps - Improve helper UAPI by explicitly defining BPF_FUNC_xxx integer values - Add libbpf *_opts API-variants for bpf_*_get_fd_by_id() functions Protocols: - TCP: implement Protective Load Balancing across switch links - TCP: allow dynamically disabling TCP-MD5 static key, reverting back to fast[er]-path - UDP: Introduce optional per-netns hash lookup table - IPv6: simplify and cleanup sockets disposal - Netlink: support different type policies for each generic netlink operation - MPTCP: add MSG_FASTOPEN and FastOpen listener side support - MPTCP: add netlink notification support for listener sockets events - SCTP: add VRF support, allowing sctp sockets binding to VRF devices - Add bridging MAC Authentication Bypass (MAB) support - Extensions for Ethernet VPN bridging implementation to better support multicast scenarios - More work for Wi-Fi 7 support, comprising conversion of all the existing drivers to internal TX queue usage - IPSec: introduce a new offload type (packet offload) allowing complete header processing and crypto offloading - IPSec: extended ack support for more descriptive XFRM error reporting - RXRPC: increase SACK table size and move processing into a per-local endpoint kernel thread, reducing considerably the required locking - IEEE 802154: synchronous send frame and extended filtering support, initial support for scanning available 15.4 networks - Tun: bump the link speed from 10Mbps to 10Gbps - Tun/VirtioNet: implement UDP segmentation offload support Driver API: - PHY/SFP: improve power level switching between standard level 1 and the higher power levels - New API for netdev <-> devlink_port linkage - PTP: convert existing drivers to new frequency adjustment implementation - DSA: add support for rx offloading - Autoload DSA tagging driver when dynamically changing protocol - Add new PCP and APPTRUST attributes to Data Center Bridging - Add configuration support for 800Gbps link speed - Add devlink port function attribute to enable/disable RoCE and migratable - Extend devlink-rate to support strict prioriry and weighted fair queuing - Add devlink support to directly reading from region memory - New device tree helper to fetch MAC address from nvmem - New big TCP helper to simplify temporary header stripping New hardware / drivers: - Ethernet: - Marvel Octeon CNF95N and CN10KB Ethernet Switches - Marvel Prestera AC5X Ethernet Switch - WangXun 10 Gigabit NIC - Motorcomm yt8521 Gigabit Ethernet - Microchip ksz9563 Gigabit Ethernet Switch - Microsoft Azure Network Adapter - Linux Automation 10Base-T1L adapter - PHY: - Aquantia AQR112 and AQR412 - Motorcomm YT8531S - PTP: - Orolia ART-CARD - WiFi: - MediaTek Wi-Fi 7 (802.11be) devices - RealTek rtw8821cu, rtw8822bu, rtw8822cu and rtw8723du USB devices - Bluetooth: - Broadcom BCM4377/4378/4387 Bluetooth chipsets - Realtek RTL8852BE and RTL8723DS - Cypress.CYW4373A0 WiFi + Bluetooth combo device Drivers: - CAN: - gs_usb: bus error reporting support - kvaser_usb: listen only and bus error reporting support - Ethernet NICs: - Intel (100G): - extend action skbedit to RX queue mapping - implement devlink-rate support - support direct read from memory - nVidia/Mellanox (mlx5): - SW steering improvements, increasing rules update rate - Support for enhanced events compression - extend H/W offload packet manipulation capabilities - implement IPSec packet offload mode - nVidia/Mellanox (mlx4): - better big TCP support - Netronome Ethernet NICs (nfp): - IPsec offload support - add support for multicast filter - Broadcom: - RSS and PTP support improvements - AMD/SolarFlare: - netlink extened ack improvements - add basic flower matches to offload, and related stats - Virtual NICs: - ibmvnic: introduce affinity hint support - small / embedded: - FreeScale fec: add initial XDP support - Marvel mv643xx_eth: support MII/GMII/RGMII modes for Kirkwood - TI am65-cpsw: add suspend/resume support - Mediatek MT7986: add RX wireless wthernet dispatch support - Realtek 8169: enable GRO software interrupt coalescing per default - Ethernet high-speed switches: - Microchip (sparx5): - add support for Sparx5 TC/flower H/W offload via VCAP - Mellanox mlxsw: - add 802.1X and MAC Authentication Bypass offload support - add ip6gre support - Embedded Ethernet switches: - Mediatek (mtk_eth_soc): - improve PCS implementation, add DSA untag support - enable flow offload support - Renesas: - add rswitch R-Car Gen4 gPTP support - Microchip (lan966x): - add full XDP support - add TC H/W offload via VCAP - enable PTP on bridge interfaces - Microchip (ksz8): - add MTU support for KSZ8 series - Qualcomm 802.11ax WiFi (ath11k): - support configuring channel dwell time during scan - MediaTek WiFi (mt76): - enable Wireless Ethernet Dispatch (WED) offload support - add ack signal support - enable coredump support - remain_on_channel support - Intel WiFi (iwlwifi): - enable Wi-Fi 7 Extremely High Throughput (EHT) PHY capabilities - 320 MHz channels support - RealTek WiFi (rtw89): - new dynamic header firmware format support - wake-over-WLAN support" * tag 'net-next-6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (2002 commits) ipvs: fix type warning in do_div() on 32 bit net: lan966x: Remove a useless test in lan966x_ptp_add_trap() net: ipa: add IPA v4.7 support dt-bindings: net: qcom,ipa: Add SM6350 compatible bnxt: Use generic HBH removal helper in tx path IPv6/GRO: generic helper to remove temporary HBH/jumbo header in driver selftests: forwarding: Add bridge MDB test selftests: forwarding: Rename bridge_mdb test bridge: mcast: Support replacement of MDB port group entries bridge: mcast: Allow user space to specify MDB entry routing protocol bridge: mcast: Allow user space to add (*, G) with a source list and filter mode bridge: mcast: Add support for (*, G) with a source list and filter mode bridge: mcast: Avoid arming group timer when (S, G) corresponds to a source bridge: mcast: Add a flag for user installed source entries bridge: mcast: Expose __br_multicast_del_group_src() bridge: mcast: Expose br_multicast_new_group_src() bridge: mcast: Add a centralized error path bridge: mcast: Place netlink policy before validation functions bridge: mcast: Split (*, G) and (S, G) addition into different functions bridge: mcast: Do not derive entry type from its filter mode ...
2022-11-18bpf: Introduce bpf_obj_newKumar Kartikeya Dwivedi1-0/+16
Introduce type safe memory allocator bpf_obj_new for BPF programs. The kernel side kfunc is named bpf_obj_new_impl, as passing hidden arguments to kfuncs still requires having them in prototype, unlike BPF helpers which always take 5 arguments and have them checked using bpf_func_proto in verifier, ignoring unset argument types. Introduce __ign suffix to ignore a specific kfunc argument during type checks, then use this to introduce support for passing type metadata to the bpf_obj_new_impl kfunc. The user passes BTF ID of the type it wants to allocates in program BTF, the verifier then rewrites the first argument as the size of this type, after performing some sanity checks (to ensure it exists and it is a struct type). The second argument is also fixed up and passed by the verifier. This is the btf_struct_meta for the type being allocated. It would be needed mostly for the offset array which is required for zero initializing special fields while leaving the rest of storage in unitialized state. It would also be needed in the next patch to perform proper destruction of the object's special fields. Under the hood, bpf_obj_new will call bpf_mem_alloc and bpf_mem_free, using the any context BPF memory allocator introduced recently. To this end, a global instance of the BPF memory allocator is initialized on boot to be used for this purpose. This 'bpf_global_ma' serves all allocations for bpf_obj_new. In the future, bpf_obj_new variants will allow specifying a custom allocator. Note that now that bpf_obj_new can be used to allocate objects that can be linked to BPF linked list (when future linked list helpers are available), we need to also free the elements using bpf_mem_free. However, since the draining of elements is done outside the bpf_spin_lock, we need to do migrate_disable around the call since bpf_list_head_free can be called from map free path where migration is enabled. Otherwise, when called from BPF programs migration is already disabled. A convenience macro is included in the bpf_experimental.h header to hide over the ugly details of the implementation, leading to user code looking similar to a language level extension which allocates and constructs fields of a user type. struct bar { struct bpf_list_node node; }; struct foo { struct bpf_spin_lock lock; struct bpf_list_head head __contains(bar, node); }; void prog(void) { struct foo *f; f = bpf_obj_new(typeof(*f)); if (!f) return; ... } A key piece of this story is still missing, i.e. the free function, which will come in the next patch. Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Link: https://lore.kernel.org/r/20221118015614.2013203-14-memxor@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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