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| * bpf: Fix propagation of 32 bit unsigned bounds from 64 bit boundsDaniel Borkmann2021-04-271-5/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Similarly as b02709587ea3 ("bpf: Fix propagation of 32-bit signed bounds from 64-bit bounds."), we also need to fix the propagation of 32 bit unsigned bounds from 64 bit counterparts. That is, really only set the u32_{min,max}_value when /both/ {umin,umax}_value safely fit in 32 bit space. For example, the register with a umin_value == 1 does /not/ imply that u32_min_value is also equal to 1, since umax_value could be much larger than 32 bit subregister can hold, and thus u32_min_value is in the interval [0,1] instead. Before fix, invalid tracking result of R2_w=inv1: [...] 5: R0_w=inv1337 R1=ctx(id=0,off=0,imm=0) R2_w=inv(id=0) R10=fp0 5: (35) if r2 >= 0x1 goto pc+1 [...] // goto path 7: R0=inv1337 R1=ctx(id=0,off=0,imm=0) R2=inv(id=0,umin_value=1) R10=fp0 7: (b6) if w2 <= 0x1 goto pc+1 [...] // goto path 9: R0=inv1337 R1=ctx(id=0,off=0,imm=0) R2=inv(id=0,smin_value=-9223372036854775807,smax_value=9223372032559808513,umin_value=1,umax_value=18446744069414584321,var_off=(0x1; 0xffffffff00000000),s32_min_value=1,s32_max_value=1,u32_max_value=1) R10=fp0 9: (bc) w2 = w2 10: R0=inv1337 R1=ctx(id=0,off=0,imm=0) R2_w=inv1 R10=fp0 [...] After fix, correct tracking result of R2_w=inv(id=0,umax_value=1,var_off=(0x0; 0x1)): [...] 5: R0_w=inv1337 R1=ctx(id=0,off=0,imm=0) R2_w=inv(id=0) R10=fp0 5: (35) if r2 >= 0x1 goto pc+1 [...] // goto path 7: R0=inv1337 R1=ctx(id=0,off=0,imm=0) R2=inv(id=0,umin_value=1) R10=fp0 7: (b6) if w2 <= 0x1 goto pc+1 [...] // goto path 9: R0=inv1337 R1=ctx(id=0,off=0,imm=0) R2=inv(id=0,smax_value=9223372032559808513,umax_value=18446744069414584321,var_off=(0x0; 0xffffffff00000001),s32_min_value=0,s32_max_value=1,u32_max_value=1) R10=fp0 9: (bc) w2 = w2 10: R0=inv1337 R1=ctx(id=0,off=0,imm=0) R2_w=inv(id=0,umax_value=1,var_off=(0x0; 0x1)) R10=fp0 [...] Thus, same issue as in b02709587ea3 holds for unsigned subregister tracking. Also, align __reg64_bound_u32() similarly to __reg64_bound_s32() as done in b02709587ea3 to make them uniform again. Fixes: 3f50f132d840 ("bpf: Verifier, do explicit ALU32 bounds tracking") Reported-by: Manfred Paul (@_manfp) Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Alexei Starovoitov <ast@kernel.org>
| * bpf: Allow trampoline re-attach for tracing and lsm programsJiri Olsa2021-04-252-8/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently we don't allow re-attaching of trampolines. Once it's detached, it can't be re-attach even when the program is still loaded. Adding the possibility to re-attach the loaded tracing and lsm programs. Fixing missing unlock with proper cleanup goto jump reported by Julia. Reported-by: kernel test robot <lkp@intel.com> Reported-by: Julia Lawall <julia.lawall@lip6.fr> Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Toke Høiland-Jørgensen <toke@redhat.com> Acked-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: KP Singh <kpsingh@kernel.org> Link: https://lore.kernel.org/bpf/20210414195147.1624932-2-jolsa@kernel.org
| * Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-nextDavid S. Miller2021-04-255-6/+396
| |\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Alexei Starovoitov says: ==================== pull-request: bpf-next 2021-04-23 The following pull-request contains BPF updates for your *net-next* tree. We've added 69 non-merge commits during the last 22 day(s) which contain a total of 69 files changed, 3141 insertions(+), 866 deletions(-). The main changes are: 1) Add BPF static linker support for extern resolution of global, from Andrii. 2) Refine retval for bpf_get_task_stack helper, from Dave. 3) Add a bpf_snprintf helper, from Florent. 4) A bunch of miscellaneous improvements from many developers. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
| | * bpf: Remove unnecessary map checks for ARG_PTR_TO_CONST_STRFlorent Revest2021-04-231-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | reg->type is enforced by check_reg_type() and map should never be NULL (it would already have been dereferenced anyway) so these checks are unnecessary. Reported-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Florent Revest <revest@chromium.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20210422235543.4007694-3-revest@chromium.org
| | * bpf: Notify user if we ever hit a bpf_snprintf verifier bugFlorent Revest2021-04-231-2/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In check_bpf_snprintf_call(), a map_direct_value_addr() of the fmt map should never fail because it has already been checked by ARG_PTR_TO_CONST_STR. But if it ever fails, it's better to error out with an explicit debug message rather than silently fail. Reported-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Florent Revest <revest@chromium.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20210422235543.4007694-2-revest@chromium.org
| | * bpf: Refine retval for bpf_get_task_stack helperDave Marchevsky2021-04-191-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Verifier can constrain the min/max bounds of bpf_get_task_stack's return value more tightly than the default tnum_unknown. Like bpf_get_stack, return value is num bytes written into a caller-supplied buf, or error, so do_refine_retval_range will work. Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Song Liu <songliubraving@fb.com> Link: https://lore.kernel.org/bpf/20210416204704.2816874-2-davemarchevsky@fb.com
| | * bpf: Add a bpf_snprintf helperFlorent Revest2021-04-192-0/+91
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The implementation takes inspiration from the existing bpf_trace_printk helper but there are a few differences: To allow for a large number of format-specifiers, parameters are provided in an array, like in bpf_seq_printf. Because the output string takes two arguments and the array of parameters also takes two arguments, the format string needs to fit in one argument. Thankfully, ARG_PTR_TO_CONST_STR is guaranteed to point to a zero-terminated read-only map so we don't need a format string length arg. Because the format-string is known at verification time, we also do a first pass of format string validation in the verifier logic. This makes debugging easier. Signed-off-by: Florent Revest <revest@chromium.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20210419155243.1632274-4-revest@chromium.org
| | * bpf: Add a ARG_PTR_TO_CONST_STR argument typeFlorent Revest2021-04-191-0/+41
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This type provides the guarantee that an argument is going to be a const pointer to somewhere in a read-only map value. It also checks that this pointer is followed by a zero character before the end of the map value. Signed-off-by: Florent Revest <revest@chromium.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20210419155243.1632274-3-revest@chromium.org
| | * bpf: Factorize bpf_trace_printk and bpf_seq_printfFlorent Revest2021-04-191-0/+256
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Two helpers (trace_printk and seq_printf) have very similar implementations of format string parsing and a third one is coming (snprintf). To avoid code duplication and make the code easier to maintain, this moves the operations associated with format string parsing (validation and argument sanitization) into one generic function. The implementation of the two existing helpers already drifted quite a bit so unifying them entailed a lot of changes: - bpf_trace_printk always expected fmt[fmt_size] to be the terminating NULL character, this is no longer true, the first 0 is terminating. - bpf_trace_printk now supports %% (which produces the percentage char). - bpf_trace_printk now skips width formating fields. - bpf_trace_printk now supports the X modifier (capital hexadecimal). - bpf_trace_printk now supports %pK, %px, %pB, %pi4, %pI4, %pi6 and %pI6 - argument casting on 32 bit has been simplified into one macro and using an enum instead of obscure int increments. - bpf_seq_printf now uses bpf_trace_copy_string instead of strncpy_from_kernel_nofault and handles the %pks %pus specifiers. - bpf_seq_printf now prints longs correctly on 32 bit architectures. - both were changed to use a global per-cpu tmp buffer instead of one stack buffer for trace_printk and 6 small buffers for seq_printf. - to avoid per-cpu buffer usage conflict, these helpers disable preemption while the per-cpu buffer is in use. - both helpers now support the %ps and %pS specifiers to print symbols. The implementation is also moved from bpf_trace.c to helpers.c because the upcoming bpf_snprintf helper will be made available to all BPF programs and will need it. Signed-off-by: Florent Revest <revest@chromium.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20210419155243.1632274-2-revest@chromium.org
| | * bpf: Return target info when a tracing bpf_link is queriedToke Høiland-Jørgensen2021-04-131-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There is currently no way to discover the target of a tracing program attachment after the fact. Add this information to bpf_link_info and return it when querying the bpf_link fd. Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20210413091607.58945-1-toke@redhat.com
| | * bpf, inode: Remove second initialization of the bpf_preload_lockMuhammad Usama Anjum2021-04-061-2/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | bpf_preload_lock is already defined with DEFINE_MUTEX(). There is no need to initialize it again. Remove the extraneous initialization. Signed-off-by: Muhammad Usama Anjum <musamaanjum@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20210405194904.GA148013@LEGION
| | * bpf: Remove unused parameter from ___bpf_prog_runHe Fengqing2021-04-031-4/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 'stack' parameter is not used in ___bpf_prog_run() after f696b8f471ec ("bpf: split bpf core interpreter"), the base address have been set to FP reg. So consequently remove it. Signed-off-by: He Fengqing <hefengqing@huawei.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Song Liu <songliubraving@fb.com> Link: https://lore.kernel.org/bpf/20210331075135.3850782-1-hefengqing@huawei.com
| * | Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski2021-04-171-74/+156
| |\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | drivers/net/ethernet/stmicro/stmmac/stmmac_main.c - keep the ZC code, drop the code related to reinit net/bridge/netfilter/ebtables.c - fix build after move to net_generic Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| * \ \ Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski2021-04-095-5/+48
| |\ \ \ | | |_|/ | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Conflicts: MAINTAINERS - keep Chandrasekar drivers/net/ethernet/mellanox/mlx5/core/en_main.c - simple fix + trust the code re-added to param.c in -next is fine include/linux/bpf.h - trivial include/linux/ethtool.h - trivial, fix kdoc while at it include/linux/skmsg.h - move to relevant place in tcp.c, comment re-wrapped net/core/skmsg.c - add the sk = sk // sk = NULL around calls net/tipc/crypto.c - trivial Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| * | | sock_map: Introduce BPF_SK_SKB_VERDICTCong Wang2021-04-011-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Reusing BPF_SK_SKB_STREAM_VERDICT is possible but its name is confusing and more importantly we still want to distinguish them from user-space. So we can just reuse the stream verdict code but introduce a new type of eBPF program, skb_verdict. Users are not allowed to attach stream_verdict and skb_verdict programs to the same map. Signed-off-by: Cong Wang <cong.wang@bytedance.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: John Fastabend <john.fastabend@gmail.com> Link: https://lore.kernel.org/bpf/20210331023237.41094-10-xiyou.wangcong@gmail.com
| * | | bpf: Remove redundant assignment of variable idColin Ian King2021-03-301-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The variable id is being assigned a value that is never read, the assignment is redundant and can be removed. Addresses-Coverity: ("Unused value") Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Song Liu <songliubraving@fb.com> Link: https://lore.kernel.org/bpf/20210326194348.623782-1-colin.king@canonical.com
| * | | bpf: Support bpf program calling kernel functionMartin KaFai Lau2021-03-265-35/+430
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds support to BPF verifier to allow bpf program calling kernel function directly. The use case included in this set is to allow bpf-tcp-cc to directly call some tcp-cc helper functions (e.g. "tcp_cong_avoid_ai()"). Those functions have already been used by some kernel tcp-cc implementations. This set will also allow the bpf-tcp-cc program to directly call the kernel tcp-cc implementation, For example, a bpf_dctcp may only want to implement its own dctcp_cwnd_event() and reuse other dctcp_*() directly from the kernel tcp_dctcp.c instead of reimplementing (or copy-and-pasting) them. The tcp-cc kernel functions mentioned above will be white listed for the struct_ops bpf-tcp-cc programs to use in a later patch. The white listed functions are not bounded to a fixed ABI contract. Those functions have already been used by the existing kernel tcp-cc. If any of them has changed, both in-tree and out-of-tree kernel tcp-cc implementations have to be changed. The same goes for the struct_ops bpf-tcp-cc programs which have to be adjusted accordingly. This patch is to make the required changes in the bpf verifier. First change is in btf.c, it adds a case in "btf_check_func_arg_match()". When the passed in "btf->kernel_btf == true", it means matching the verifier regs' states with a kernel function. This will handle the PTR_TO_BTF_ID reg. It also maps PTR_TO_SOCK_COMMON, PTR_TO_SOCKET, and PTR_TO_TCP_SOCK to its kernel's btf_id. In the later libbpf patch, the insn calling a kernel function will look like: insn->code == (BPF_JMP | BPF_CALL) insn->src_reg == BPF_PSEUDO_KFUNC_CALL /* <- new in this patch */ insn->imm == func_btf_id /* btf_id of the running kernel */ [ For the future calling function-in-kernel-module support, an array of module btf_fds can be passed at the load time and insn->off can be used to index into this array. ] At the early stage of verifier, the verifier will collect all kernel function calls into "struct bpf_kfunc_desc". Those descriptors are stored in "prog->aux->kfunc_tab" and will be available to the JIT. Since this "add" operation is similar to the current "add_subprog()" and looking for the same insn->code, they are done together in the new "add_subprog_and_kfunc()". In the "do_check()" stage, the new "check_kfunc_call()" is added to verify the kernel function call instruction: 1. Ensure the kernel function can be used by a particular BPF_PROG_TYPE. A new bpf_verifier_ops "check_kfunc_call" is added to do that. The bpf-tcp-cc struct_ops program will implement this function in a later patch. 2. Call "btf_check_kfunc_args_match()" to ensure the regs can be used as the args of a kernel function. 3. Mark the regs' type, subreg_def, and zext_dst. At the later do_misc_fixups() stage, the new fixup_kfunc_call() will replace the insn->imm with the function address (relative to __bpf_call_base). If needed, the jit can find the btf_func_model by calling the new bpf_jit_find_kfunc_model(prog, insn). With the imm set to the function address, "bpftool prog dump xlated" will be able to display the kernel function calls the same way as it displays other bpf helper calls. gpl_compatible program is required to call kernel function. This feature currently requires JIT. The verifier selftests are adjusted because of the changes in the verbose log in add_subprog_and_kfunc(). Signed-off-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20210325015142.1544736-1-kafai@fb.com
| * | | bpf: Refactor btf_check_func_arg_matchMartin KaFai Lau2021-03-262-75/+88
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch moved the subprog specific logic from btf_check_func_arg_match() to the new btf_check_subprog_arg_match(). The core logic is left in btf_check_func_arg_match() which will be reused later to check the kernel function call. The "if (!btf_type_is_ptr(t))" is checked first to improve the indentation which will be useful for a later patch. Some of the "btf_kind_str[]" usages is replaced with the shortcut "btf_type_str(t)". Signed-off-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20210325015136.1544504-1-kafai@fb.com
| * | | bpf: Simplify freeing logic in linfo and jited_linfoMartin KaFai Lau2021-03-263-26/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch simplifies the linfo freeing logic by combining "bpf_prog_free_jited_linfo()" and "bpf_prog_free_unused_jited_linfo()" into the new "bpf_prog_jit_attempt_done()". It is a prep work for the kernel function call support. In a later patch, freeing the kernel function call descriptors will also be done in the "bpf_prog_jit_attempt_done()". "bpf_prog_free_linfo()" is removed since it is only called by "__bpf_prog_put_noref()". The kvfree() are directly called instead. It also takes this chance to s/kcalloc/kvcalloc/ for the jited_linfo allocation. Signed-off-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20210325015130.1544323-1-kafai@fb.com
| * | | bpf: Add support for batched ops in LPM trie mapsPedro Tammela2021-03-251-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Suggested-by: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: Pedro Tammela <pctammela@mojatatu.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20210323025058.315763-2-pctammela@gmail.com
| * | | bpf: Fix NULL pointer dereference in bpf_get_local_storage() helperYonghong Song2021-03-252-6/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Jiri Olsa reported a bug ([1]) in kernel where cgroup local storage pointer may be NULL in bpf_get_local_storage() helper. There are two issues uncovered by this bug: (1). kprobe or tracepoint prog incorrectly sets cgroup local storage before prog run, (2). due to change from preempt_disable to migrate_disable, preemption is possible and percpu storage might be overwritten by other tasks. This issue (1) is fixed in [2]. This patch tried to address issue (2). The following shows how things can go wrong: task 1: bpf_cgroup_storage_set() for percpu local storage preemption happens task 2: bpf_cgroup_storage_set() for percpu local storage preemption happens task 1: run bpf program task 1 will effectively use the percpu local storage setting by task 2 which will be either NULL or incorrect ones. Instead of just one common local storage per cpu, this patch fixed the issue by permitting 8 local storages per cpu and each local storage is identified by a task_struct pointer. This way, we allow at most 8 nested preemption between bpf_cgroup_storage_set() and bpf_cgroup_storage_unset(). The percpu local storage slot is released (calling bpf_cgroup_storage_unset()) by the same task after bpf program finished running. bpf_test_run() is also fixed to use the new bpf_cgroup_storage_set() interface. The patch is tested on top of [2] with reproducer in [1]. Without this patch, kernel will emit error in 2-3 minutes. With this patch, after one hour, still no error. [1] https://lore.kernel.org/bpf/CAKH8qBuXCfUz=w8L+Fj74OaUpbosO29niYwTki7e3Ag044_aww@mail.gmail.com/T [2] https://lore.kernel.org/bpf/20210309185028.3763817-1-yhs@fb.com Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Roman Gushchin <guro@fb.com> Link: https://lore.kernel.org/bpf/20210323055146.3334476-1-yhs@fb.com
| * | | bpf: Undo ptr_to_map_key alu sanitation for nowDaniel Borkmann2021-03-261-14/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Remove PTR_TO_MAP_KEY for the time being from being sanitized on pointer ALU through sanitize_ptr_alu() mainly for 3 reasons: 1) It's currently unused and not available from unprivileged. However that by itself is not yet a strong reason to drop the code. 2) Commit 69c087ba6225 ("bpf: Add bpf_for_each_map_elem() helper") implemented the sanitation not fully correct in that unlike stack or map_value pointer it doesn't probe whether the access to the map key /after/ the simulated ALU operation is still in bounds. This means that the generated mask can truncate the offset in the non-speculative domain whereas it should only truncate in the speculative domain. The verifier should instead reject such program as we do for other types. 3) Given the recent fixes from f232326f6966 ("bpf: Prohibit alu ops for pointer types not defining ptr_limit"), 10d2bb2e6b1d ("bpf: Fix off-by-one for area size in creating mask to left"), b5871dca250c ("bpf: Simplify alu_limit masking for pointer arithmetic") as well as 1b1597e64e1a ("bpf: Add sanity check for upper ptr_limit") the code changed quite a bit and the merge in efd13b71a3fa broke the PTR_TO_MAP_KEY case due to an incorrect merge conflict. Remove the relevant pieces for the time being and we can rework the PTR_TO_MAP_KEY case once everything settles. Fixes: efd13b71a3fa ("Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net") Fixes: 69c087ba6225 ("bpf: Add bpf_for_each_map_elem() helper") Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
| * | | Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-nextDavid S. Miller2021-03-255-23/+16
| |\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Alexei Starovoitov says: ==================== pull-request: bpf-next 2021-03-24 The following pull-request contains BPF updates for your *net-next* tree. We've added 37 non-merge commits during the last 15 day(s) which contain a total of 65 files changed, 3200 insertions(+), 738 deletions(-). The main changes are: 1) Static linking of multiple BPF ELF files, from Andrii. 2) Move drop error path to devmap for XDP_REDIRECT, from Lorenzo. 3) Spelling fixes from various folks. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
| | * | | bpf: Avoid old-style declaration warningsArnd Bergmann2021-03-241-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | gcc -Wextra wants type modifiers in the normal order: kernel/bpf/bpf_lsm.c:70:1: error: 'static' is not at beginning of declaration [-Werror=old-style-declaration] 70 | const static struct bpf_func_proto bpf_bprm_opts_set_proto = { | ^~~~~ kernel/bpf/bpf_lsm.c:91:1: error: 'static' is not at beginning of declaration [-Werror=old-style-declaration] 91 | const static struct bpf_func_proto bpf_ima_inode_hash_proto = { | ^~~~~ Fixes: 3f6719c7b62f ("bpf: Add bpf_bprm_opts_set helper") Fixes: 27672f0d280a ("bpf: Add a BPF helper for getting the IMA hash of an inode") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: KP Singh <kpsingh@kernel.org> Link: https://lore.kernel.org/bpf/20210322215201.1097281-1-arnd@kernel.org
| | * | | bpf: Remove insn_buf[] declaration in inner blockJianlin Lv2021-03-191-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Two insn_buf[16] variables are declared in the function which acts on function scope and block scope respectively. The statement in the inner block is redundant, so remove it. Signed-off-by: Jianlin Lv <Jianlin.Lv@arm.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20210318024851.49693-1-Jianlin.Lv@arm.com
| | * | | bpf, devmap: Move drop error path to devmap for XDP_REDIRECTLorenzo Bianconi2021-03-181-18/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We want to change the current ndo_xdp_xmit drop semantics because it will allow us to implement better queue overflow handling. This is working towards the larger goal of a XDP TX queue-hook. Move XDP_REDIRECT error path handling from each XDP ethernet driver to devmap code. According to the new APIs, the driver running the ndo_xdp_xmit pointer, will break tx loop whenever the hw reports a tx error and it will just return to devmap caller the number of successfully transmitted frames. It will be devmap responsibility to free dropped frames. Move each XDP ndo_xdp_xmit capable driver to the new APIs: - veth - virtio-net - mvneta - mvpp2 - socionext - amazon ena - bnxt - freescale (dpaa2, dpaa) - xen-frontend - qede - ice - igb - ixgbe - i40e - mlx5 - ti (cpsw, cpsw-new) - tun - sfc Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Ioana Ciornei <ioana.ciornei@nxp.com> Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org> Reviewed-by: Camelia Groza <camelia.groza@nxp.com> Acked-by: Edward Cree <ecree.xilinx@gmail.com> Acked-by: Jesper Dangaard Brouer <brouer@redhat.com> Acked-by: Shay Agroskin <shayagr@amazon.com> Link: https://lore.kernel.org/bpf/ed670de24f951cfd77590decf0229a0ad7fd12f6.1615201152.git.lorenzo@kernel.org
| | * | | bpf: Make symbol 'bpf_task_storage_busy' staticWei Yongjun2021-03-161-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The sparse tool complains as follows: kernel/bpf/bpf_task_storage.c:23:1: warning: symbol '__pcpu_scope_bpf_task_storage_busy' was not declared. Should it be static? This symbol is not used outside of bpf_task_storage.c, so this commit marks it static. Fixes: bc235cdb423a ("bpf: Prevent deadlock from recursive bpf_task_storage_[get|delete]") Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Song Liu <songliubraving@fb.com> Link: https://lore.kernel.org/bpf/20210311131505.1901509-1-weiyongjun1@huawei.com
| | * | | kernel/bpf/: Fix misspellings using codespell toolLiu xuzhi2021-03-161-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A typo is found out by codespell tool in 34th lines of hashtab.c: $ codespell ./kernel/bpf/ ./hashtab.c:34 : differrent ==> different Fix a typo found by codespell. Signed-off-by: Liu xuzhi <liu.xuzhi@zte.com.cn> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20210311123103.323589-1-liu.xuzhi@zte.com.cn
| * | | | Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netDavid S. Miller2021-03-257-70/+217
| |\ \ \ \ | | |/ / / | |/| | | | | | | | Signed-off-by: David S. Miller <davem@davemloft.net>
| * | | | Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-nextDavid S. Miller2021-03-0913-140/+658
| |\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Alexei Starovoitov says: ==================== pull-request: bpf-next 2021-03-09 The following pull-request contains BPF updates for your *net-next* tree. We've added 90 non-merge commits during the last 17 day(s) which contain a total of 114 files changed, 5158 insertions(+), 1288 deletions(-). The main changes are: 1) Faster bpf_redirect_map(), from Björn. 2) skmsg cleanup, from Cong. 3) Support for floating point types in BTF, from Ilya. 4) Documentation for sys_bpf commands, from Joe. 5) Support for sk_lookup in bpf_prog_test_run, form Lorenz. 6) Enable task local storage for tracing programs, from Song. 7) bpf_for_each_map_elem() helper, from Yonghong. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
| | * | | | bpf, xdp: Restructure redirect actionsBjörn Töpel2021-03-102-2/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The XDP_REDIRECT implementations for maps and non-maps are fairly similar, but obviously need to take different code paths depending on if the target is using a map or not. Today, the redirect targets for XDP either uses a map, or is based on ifindex. Here, the map type and id are added to bpf_redirect_info, instead of the actual map. Map type, map item/ifindex, and the map_id (if any) is passed to xdp_do_redirect(). For ifindex-based redirect, used by the bpf_redirect() XDP BFP helper, a special map type/id are used. Map type of UNSPEC together with map id equal to INT_MAX has the special meaning of an ifindex based redirect. Note that valid map ids are 1 inclusive, INT_MAX exclusive ([1,INT_MAX[). In addition to making the code easier to follow, using explicit type and id in bpf_redirect_info has a slight positive performance impact by avoiding a pointer indirection for the map type lookup, and instead use the cacheline for bpf_redirect_info. Since the actual map is not passed via bpf_redirect_info anymore, the map lookup is only done in the BPF helper. This means that the bpf_clear_redirect_map() function can be removed. The actual map item is RCU protected. The bpf_redirect_info flags member is not used by XDP, and not read/written any more. The map member is only written to when required/used, and not unconditionally. Signed-off-by: Björn Töpel <bjorn.topel@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com> Acked-by: Jesper Dangaard Brouer <brouer@redhat.com> Acked-by: Toke Høiland-Jørgensen <toke@redhat.com> Link: https://lore.kernel.org/bpf/20210308112907.559576-3-bjorn.topel@gmail.com
| | * | | | bpf, xdp: Make bpf_redirect_map() a map operationBjörn Töpel2021-03-103-5/+32
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently the bpf_redirect_map() implementation dispatches to the correct map-lookup function via a switch-statement. To avoid the dispatching, this change adds bpf_redirect_map() as a map operation. Each map provides its bpf_redirect_map() version, and correct function is automatically selected by the BPF verifier. A nice side-effect of the code movement is that the map lookup functions are now local to the map implementation files, which removes one additional function call. Signed-off-by: Björn Töpel <bjorn.topel@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Jesper Dangaard Brouer <brouer@redhat.com> Acked-by: Toke Høiland-Jørgensen <toke@redhat.com> Link: https://lore.kernel.org/bpf/20210308112907.559576-2-bjorn.topel@gmail.com
| | * | | | bpf: Add BTF_KIND_FLOAT supportIlya Leoshkevich2021-03-041-2/+81
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | On the kernel side, introduce a new btf_kind_operations. It is similar to that of BTF_KIND_INT, however, it does not need to handle encodings and bit offsets. Do not implement printing, since the kernel does not know how to format floating-point values. Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20210226202256.116518-7-iii@linux.ibm.com
| | * | | | bpf: Add arraymap support for bpf_for_each_map_elem() helperYonghong Song2021-02-261-0/+40
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch added support for arraymap and percpu arraymap. Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20210226204928.3885192-1-yhs@fb.com
| | * | | | bpf: Add hashtab support for bpf_for_each_map_elem() helperYonghong Song2021-02-262-0/+92
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch added support for hashmap, percpu hashmap, lru hashmap and percpu lru hashmap. Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20210226204927.3885020-1-yhs@fb.com
| | * | | | bpf: Add bpf_for_each_map_elem() helperYonghong Song2021-02-263-13/+213
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The bpf_for_each_map_elem() helper is introduced which iterates all map elements with a callback function. The helper signature looks like long bpf_for_each_map_elem(map, callback_fn, callback_ctx, flags) and for each map element, the callback_fn will be called. For example, like hashmap, the callback signature may look like long callback_fn(map, key, val, callback_ctx) There are two known use cases for this. One is from upstream ([1]) where a for_each_map_elem helper may help implement a timeout mechanism in a more generic way. Another is from our internal discussion for a firewall use case where a map contains all the rules. The packet data can be compared to all these rules to decide allow or deny the packet. For array maps, users can already use a bounded loop to traverse elements. Using this helper can avoid using bounded loop. For other type of maps (e.g., hash maps) where bounded loop is hard or impossible to use, this helper provides a convenient way to operate on all elements. For callback_fn, besides map and map element, a callback_ctx, allocated on caller stack, is also passed to the callback function. This callback_ctx argument can provide additional input and allow to write to caller stack for output. If the callback_fn returns 0, the helper will iterate through next element if available. If the callback_fn returns 1, the helper will stop iterating and returns to the bpf program. Other return values are not used for now. Currently, this helper is only available with jit. It is possible to make it work with interpreter with so effort but I leave it as the future work. [1]: https://lore.kernel.org/bpf/20210122205415.113822-1-xiyou.wangcong@gmail.com/ Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20210226204925.3884923-1-yhs@fb.com
| | * | | | bpf: Change return value of verifier function add_subprog()Yonghong Song2021-02-261-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, verifier function add_subprog() returns 0 for success and negative value for failure. Change the return value to be the subprog number for success. This functionality will be used in the next patch to save a call to find_subprog(). Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20210226204924.3884848-1-yhs@fb.com
| | * | | | bpf: Refactor check_func_call() to allow callback functionYonghong Song2021-02-261-17/+43
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Later proposed bpf_for_each_map_elem() helper has callback function as one of its arguments. This patch refactored check_func_call() to permit callback function which sets callee state. Different callback functions may have different callee states. There is no functionality change for this patch. Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20210226204923.3884627-1-yhs@fb.com
| | * | | | bpf: Factor out verbose_invalid_scalar()Yonghong Song2021-02-261-11/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Factor out the function verbose_invalid_scalar() to verbose print if a scalar is not in a tnum range. There is no functionality change and the function will be used by later patch which introduced bpf_for_each_map_elem(). Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20210226204922.3884375-1-yhs@fb.com
| | * | | | bpf: Factor out visit_func_call_insn() in check_cfg()Yonghong Song2021-02-261-12/+23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | During verifier check_cfg(), all instructions are visited to ensure verifier can handle program control flows. This patch factored out function visit_func_call_insn() so it can be reused in later patch to visit callback function calls. There is no functionality change for this patch. Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20210226204920.3884136-1-yhs@fb.com
| | * | | | bpf: Rename fixup_bpf_calls and add some commentsBrendan Jackman2021-02-261-7/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This function has become overloaded, it actually does lots of diverse things in a single pass. Rename it to avoid confusion, and add some concise commentary. Signed-off-by: Brendan Jackman <jackmanb@google.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20210217104509.2423183-1-jackmanb@google.com
| | * | | | bpf: Use MAX_BPF_FUNC_REG_ARGS macroDmitrii Banshchikov2021-02-262-12/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Instead of using integer literal here and there use macro name for better context. Signed-off-by: Dmitrii Banshchikov <me@ubique.spb.ru> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/20210225202629.585485-1-me@ubique.spb.ru
| | * | | | bpf: Prevent deadlock from recursive bpf_task_storage_[get|delete]Song Liu2021-02-263-10/+62
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | BPF helpers bpf_task_storage_[get|delete] could hold two locks: bpf_local_storage_map_bucket->lock and bpf_local_storage->lock. Calling these helpers from fentry/fexit programs on functions in bpf_*_storage.c may cause deadlock on either locks. Prevent such deadlock with a per cpu counter, bpf_task_storage_busy. We need this counter to be global, because the two locks here belong to two different objects: bpf_local_storage_map and bpf_local_storage. If we pick one of them as the owner of the counter, it is still possible to trigger deadlock on the other lock. For example, if bpf_local_storage_map owns the counters, it cannot prevent deadlock on bpf_local_storage->lock when two maps are used. Signed-off-by: Song Liu <songliubraving@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/20210225234319.336131-3-songliubraving@fb.com
| | * | | | bpf: Enable task local storage for tracing programsSong Liu2021-02-264-49/+29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | To access per-task data, BPF programs usually creates a hash table with pid as the key. This is not ideal because: 1. The user need to estimate the proper size of the hash table, which may be inaccurate; 2. Big hash tables are slow; 3. To clean up the data properly during task terminations, the user need to write extra logic. Task local storage overcomes these issues and offers a better option for these per-task data. Task local storage is only available to BPF_LSM. Now enable it for tracing programs. Unlike LSM programs, tracing programs can be called in IRQ contexts. Helpers that access task local storage are updated to use raw_spin_lock_irqsave() instead of raw_spin_lock_bh(). Tracing programs can attach to functions on the task free path, e.g. exit_creds(). To avoid allocating task local storage after bpf_task_storage_free(). bpf_task_storage_get() is updated to not allocate new storage when the task is not refcounted (task->usage == 0). Signed-off-by: Song Liu <songliubraving@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: KP Singh <kpsingh@kernel.org> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/20210225234319.336131-2-songliubraving@fb.com
* | | | | | Merge tag 'selinux-pr-20210426' of ↵Linus Torvalds2021-04-271-1/+2
|\ \ \ \ \ \ | |_|_|_|_|/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux Pull selinux updates from Paul Moore: - Add support for measuring the SELinux state and policy capabilities using IMA. - A handful of SELinux/NFS patches to compare the SELinux state of one mount with a set of mount options. Olga goes into more detail in the patch descriptions, but this is important as it allows more flexibility when using NFS and SELinux context mounts. - Properly differentiate between the subjective and objective LSM credentials; including support for the SELinux and Smack. My clumsy attempt at a proper fix for AppArmor didn't quite pass muster so John is working on a proper AppArmor patch, in the meantime this set of patches shouldn't change the behavior of AppArmor in any way. This change explains the bulk of the diffstat beyond security/. - Fix a problem where we were not properly terminating the permission list for two SELinux object classes. * tag 'selinux-pr-20210426' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux: selinux: add proper NULL termination to the secclass_map permissions smack: differentiate between subjective and objective task credentials selinux: clarify task subjective and objective credentials lsm: separate security_task_getsecid() into subjective and objective variants nfs: account for selinux security context when deciding to share superblock nfs: remove unneeded null check in nfs_fill_super() lsm,selinux: add new hook to compare new mount to an existing mount selinux: fix misspellings using codespell tool selinux: fix misspellings using codespell tool selinux: measure state and policy capabilities selinux: Allow context mounts for unpriviliged overlayfs
| * | | | | lsm: separate security_task_getsecid() into subjective and objective variantsPaul Moore2021-03-221-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Of the three LSMs that implement the security_task_getsecid() LSM hook, all three LSMs provide the task's objective security credentials. This turns out to be unfortunate as most of the hook's callers seem to expect the task's subjective credentials, although a small handful of callers do correctly expect the objective credentials. This patch is the first step towards fixing the problem: it splits the existing security_task_getsecid() hook into two variants, one for the subjective creds, one for the objective creds. void security_task_getsecid_subj(struct task_struct *p, u32 *secid); void security_task_getsecid_obj(struct task_struct *p, u32 *secid); While this patch does fix all of the callers to use the correct variant, in order to keep this patch focused on the callers and to ease review, the LSMs continue to use the same implementation for both hooks. The net effect is that this patch should not change the behavior of the kernel in any way, it will be up to the latter LSM specific patches in this series to change the hook implementations and return the correct credentials. Acked-by: Mimi Zohar <zohar@linux.ibm.com> (IMA) Acked-by: Casey Schaufler <casey@schaufler-ca.com> Reviewed-by: Richard Guy Briggs <rgb@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
* | | | | | bpf: Tighten speculative pointer arithmetic maskDaniel Borkmann2021-04-161-29/+44
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This work tightens the offset mask we use for unprivileged pointer arithmetic in order to mitigate a corner case reported by Piotr and Benedict where in the speculative domain it is possible to advance, for example, the map value pointer by up to value_size-1 out-of-bounds in order to leak kernel memory via side-channel to user space. Before this change, the computed ptr_limit for retrieve_ptr_limit() helper represents largest valid distance when moving pointer to the right or left which is then fed as aux->alu_limit to generate masking instructions against the offset register. After the change, the derived aux->alu_limit represents the largest potential value of the offset register which we mask against which is just a narrower subset of the former limit. For minimal complexity, we call sanitize_ptr_alu() from 2 observation points in adjust_ptr_min_max_vals(), that is, before and after the simulated alu operation. In the first step, we retieve the alu_state and alu_limit before the operation as well as we branch-off a verifier path and push it to the verification stack as we did before which checks the dst_reg under truncation, in other words, when the speculative domain would attempt to move the pointer out-of-bounds. In the second step, we retrieve the new alu_limit and calculate the absolute distance between both. Moreover, we commit the alu_state and final alu_limit via update_alu_sanitation_state() to the env's instruction aux data, and bail out from there if there is a mismatch due to coming from different verification paths with different states. Reported-by: Piotr Krysiuk <piotras@gmail.com> Reported-by: Benedict Schlueter <benedict.schlueter@rub.de> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Tested-by: Benedict Schlueter <benedict.schlueter@rub.de>
* | | | | | bpf: Move sanitize_val_alu out of op switchDaniel Borkmann2021-04-161-6/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add a small sanitize_needed() helper function and move sanitize_val_alu() out of the main opcode switch. In upcoming work, we'll move sanitize_ptr_alu() as well out of its opcode switch so this helps to streamline both. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Alexei Starovoitov <ast@kernel.org>
* | | | | | bpf: Refactor and streamline bounds check into helperDaniel Borkmann2021-04-161-16/+33
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Move the bounds check in adjust_ptr_min_max_vals() into a small helper named sanitize_check_bounds() in order to simplify the former a bit. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Alexei Starovoitov <ast@kernel.org>
* | | | | | bpf: Improve verifier error messages for usersDaniel Borkmann2021-04-161-23/+63
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Consolidate all error handling and provide more user-friendly error messages from sanitize_ptr_alu() and sanitize_val_alu(). Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Alexei Starovoitov <ast@kernel.org>
generated by cgit v1.2.3 (git 2.25.1) at 2025-01-12 20:08:55 +0000