diff options
| -rw-r--r-- | include/uapi/linux/bpf.h | 14 | ||||
| -rw-r--r-- | kernel/bpf/syscall.c | 7 | ||||
| -rw-r--r-- | kernel/bpf/verifier.c | 3 | ||||
| -rw-r--r-- | tools/include/uapi/linux/bpf.h | 14 | ||||
| -rw-r--r-- | tools/lib/bpf/bpf.c | 8 | ||||
| -rw-r--r-- | tools/lib/bpf/bpf.h | 2 | ||||
| -rw-r--r-- | tools/testing/selftests/bpf/test_align.c | 4 | ||||
| -rw-r--r-- | tools/testing/selftests/bpf/test_verifier.c | 3 |
8 files changed, 46 insertions, 9 deletions
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 71ca8c4dc290..8481fc7676c0 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -228,6 +228,20 @@ enum bpf_attach_type { */ #define BPF_F_STRICT_ALIGNMENT (1U << 0) +/* If BPF_F_ANY_ALIGNMENT is used in BPF_PROF_LOAD command, the + * verifier will allow any alignment whatsoever. On platforms + * with strict alignment requirements for loads ands stores (such + * as sparc and mips) the verifier validates that all loads and + * stores provably follow this requirement. This flag turns that + * checking and enforcement off. + * + * It is mostly used for testing when we want to validate the + * context and memory access aspects of the verifier, but because + * of an unaligned access the alignment check would trigger before + * the one we are interested in. + */ +#define BPF_F_ANY_ALIGNMENT (1U << 1) + /* when bpf_ldimm64->src_reg == BPF_PSEUDO_MAP_FD, bpf_ldimm64->imm == fd */ #define BPF_PSEUDO_MAP_FD 1 diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index 21a366a661ac..353a8d672302 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -1367,9 +1367,14 @@ static int bpf_prog_load(union bpf_attr *attr) if (CHECK_ATTR(BPF_PROG_LOAD)) return -EINVAL; - if (attr->prog_flags & ~BPF_F_STRICT_ALIGNMENT) + if (attr->prog_flags & ~(BPF_F_STRICT_ALIGNMENT | BPF_F_ANY_ALIGNMENT)) return -EINVAL; + if (!IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && + (attr->prog_flags & BPF_F_ANY_ALIGNMENT) && + !capable(CAP_SYS_ADMIN)) + return -EPERM; + /* copy eBPF program license from user space */ if (strncpy_from_user(license, u64_to_user_ptr(attr->license), sizeof(license) - 1) < 0) diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 1f4c88ce58de..4ce032c4acd0 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -6440,6 +6440,9 @@ int bpf_check(struct bpf_prog **prog, union bpf_attr *attr) if (!IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)) env->strict_alignment = true; + if (attr->prog_flags & BPF_F_ANY_ALIGNMENT) + env->strict_alignment = false; + ret = replace_map_fd_with_map_ptr(env); if (ret < 0) goto skip_full_check; diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index 13944978ada5..9e060c6a01ac 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -226,6 +226,20 @@ enum bpf_attach_type { */ #define BPF_F_STRICT_ALIGNMENT (1U << 0) +/* If BPF_F_ANY_ALIGNMENT is used in BPF_PROF_LOAD command, the + * verifier will allow any alignment whatsoever. On platforms + * with strict alignment requirements for loads ands stores (such + * as sparc and mips) the verifier validates that all loads and + * stores provably follow this requirement. This flag turns that + * checking and enforcement off. + * + * It is mostly used for testing when we want to validate the + * context and memory access aspects of the verifier, but because + * of an unaligned access the alignment check would trigger before + * the one we are interested in. + */ +#define BPF_F_ANY_ALIGNMENT (1U << 1) + /* when bpf_ldimm64->src_reg == BPF_PSEUDO_MAP_FD, bpf_ldimm64->imm == fd */ #define BPF_PSEUDO_MAP_FD 1 diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c index 482025b72839..f28ae6a68697 100644 --- a/tools/lib/bpf/bpf.c +++ b/tools/lib/bpf/bpf.c @@ -261,9 +261,9 @@ int bpf_load_program(enum bpf_prog_type type, const struct bpf_insn *insns, } int bpf_verify_program(enum bpf_prog_type type, const struct bpf_insn *insns, - size_t insns_cnt, int strict_alignment, - const char *license, __u32 kern_version, - char *log_buf, size_t log_buf_sz, int log_level) + size_t insns_cnt, __u32 prog_flags, const char *license, + __u32 kern_version, char *log_buf, size_t log_buf_sz, + int log_level) { union bpf_attr attr; @@ -277,7 +277,7 @@ int bpf_verify_program(enum bpf_prog_type type, const struct bpf_insn *insns, attr.log_level = log_level; log_buf[0] = 0; attr.kern_version = kern_version; - attr.prog_flags = strict_alignment ? BPF_F_STRICT_ALIGNMENT : 0; + attr.prog_flags = prog_flags; return sys_bpf_prog_load(&attr, sizeof(attr)); } diff --git a/tools/lib/bpf/bpf.h b/tools/lib/bpf/bpf.h index c3145ab3bdca..7f2e947d940c 100644 --- a/tools/lib/bpf/bpf.h +++ b/tools/lib/bpf/bpf.h @@ -79,7 +79,7 @@ int bpf_load_program(enum bpf_prog_type type, const struct bpf_insn *insns, __u32 kern_version, char *log_buf, size_t log_buf_sz); int bpf_verify_program(enum bpf_prog_type type, const struct bpf_insn *insns, - size_t insns_cnt, int strict_alignment, + size_t insns_cnt, __u32 prog_flags, const char *license, __u32 kern_version, char *log_buf, size_t log_buf_sz, int log_level); diff --git a/tools/testing/selftests/bpf/test_align.c b/tools/testing/selftests/bpf/test_align.c index 5f377ec53f2f..3c789d03b629 100644 --- a/tools/testing/selftests/bpf/test_align.c +++ b/tools/testing/selftests/bpf/test_align.c @@ -620,8 +620,8 @@ static int do_test_single(struct bpf_align_test *test) prog_len = probe_filter_length(prog); fd_prog = bpf_verify_program(prog_type ? : BPF_PROG_TYPE_SOCKET_FILTER, - prog, prog_len, 1, "GPL", 0, - bpf_vlog, sizeof(bpf_vlog), 2); + prog, prog_len, BPF_F_STRICT_ALIGNMENT, + "GPL", 0, bpf_vlog, sizeof(bpf_vlog), 2); if (fd_prog < 0 && test->result != REJECT) { printf("Failed to load program.\n"); printf("%s", bpf_vlog); diff --git a/tools/testing/selftests/bpf/test_verifier.c b/tools/testing/selftests/bpf/test_verifier.c index 809d8e9ac356..919f97a20203 100644 --- a/tools/testing/selftests/bpf/test_verifier.c +++ b/tools/testing/selftests/bpf/test_verifier.c @@ -12862,7 +12862,8 @@ static void do_test_single(struct bpf_test *test, bool unpriv, prog_len = probe_filter_length(prog); fd_prog = bpf_verify_program(prog_type, prog, prog_len, - test->flags & F_LOAD_WITH_STRICT_ALIGNMENT, + test->flags & F_LOAD_WITH_STRICT_ALIGNMENT ? + BPF_F_STRICT_ALIGNMENT : 0, "GPL", 0, bpf_vlog, sizeof(bpf_vlog), 1); expected_ret = unpriv && test->result_unpriv != UNDEF ? |