add_subprog_and_kfunc() combines two operations with different ordering requirements. Subprogram discovery must precede validation of func_info and line_info, while kfunc descriptors are only needed by the verifier after its initial program setup is complete. Split the helper into add_subprogs() and add_kfuncs() so each operation can be placed according to its actual dependencies. Keep both calls adjacent and in their existing phase for now, and add short comments describing their roles. No functional change is intended for valid programs.
Showing the changes to kernel (1 of 1 file). Show all
Unified · Split
| @@ -2837,7 +2837,7 @@ int bpf_add_kfunc_call(struct bpf_verifier_env *env, u32 func_id, u16 offset) · 2836 unmodified lines | ||
| 2837 | 2837 | return 0; |
| 2838 | 2838 | } |
| 2839 | 2839 | |
| 2840 | −static int add_subprog_and_kfunc(struct bpf_verifier_env *env) | |
| 2840 | +static int add_subprogs(struct bpf_verifier_env *env) | |
| 2841 | 2841 | { |
| 2842 | 2842 | struct bpf_subprog_info *subprog = env->subprog_info; |
| 2843 | 2843 | int i, ret, insn_cnt = env->prog->len, ex_cb_insn; |
| @@ -2849,8 +2849,7 @@ static int add_subprog_and_kfunc(struct bpf_verifier_env *env) · 5 unmodified lines | ||
| 2849 | 2849 | return ret; |
| 2850 | 2850 | |
| 2851 | 2851 | for (i = 0; i < insn_cnt; i++, insn++) { |
| 2852 | − if (!bpf_pseudo_func(insn) && !bpf_pseudo_call(insn) && | |
| 2853 | − !bpf_pseudo_kfunc_call(insn)) | |
| 2852 | + if (!bpf_pseudo_func(insn) && !bpf_pseudo_call(insn)) | |
| 2854 | 2853 | continue; |
| 2855 | 2854 | |
| 2856 | 2855 | if (!env->bpf_capable) { |
| @@ -2858,11 +2857,7 @@ static int add_subprog_and_kfunc(struct bpf_verifier_env *env) · 1 unmodified line | ||
| 2858 | 2857 | return -EPERM; |
| 2859 | 2858 | } |
| 2860 | 2859 | |
| 2861 | − if (bpf_pseudo_func(insn) || bpf_pseudo_call(insn)) | |
| 2862 | − ret = add_subprog(env, i + insn->imm + 1); | |
| 2863 | − else | |
| 2864 | − ret = bpf_add_kfunc_call(env, insn->imm, insn->off); | |
| 2865 | − | |
| 2860 | + ret = add_subprog(env, i + insn->imm + 1); | |
| 2866 | 2861 | if (ret < 0) |
| 2867 | 2862 | return ret; |
| 2868 | 2863 | } |
| @@ -2900,6 +2895,28 @@ static int add_subprog_and_kfunc(struct bpf_verifier_env *env) · 31 unmodified lines | ||
| 2900 | 2895 | return 0; |
| 2901 | 2896 | } |
| 2902 | 2897 | |
| 2898 | +static int add_kfuncs(struct bpf_verifier_env *env) | |
| 2899 | +{ | |
| 2900 | + struct bpf_insn *insn = env->prog->insnsi; | |
| 2901 | + int i, ret, insn_cnt = env->prog->len; | |
| 2902 | + | |
| 2903 | + for (i = 0; i < insn_cnt; i++, insn++) { | |
| 2904 | + if (!bpf_pseudo_kfunc_call(insn)) | |
| 2905 | + continue; | |
| 2906 | + | |
| 2907 | + if (!env->bpf_capable) { | |
| 2908 | + verbose(env, "loading/calling other bpf or kernel functions are allowed for CAP_BPF and CAP_SYS_ADMIN\n"); | |
| 2909 | + return -EPERM; | |
| 2910 | + } | |
| 2911 | + | |
| 2912 | + ret = bpf_add_kfunc_call(env, insn->imm, insn->off); | |
| 2913 | + if (ret < 0) | |
| 2914 | + return ret; | |
| 2915 | + } | |
| 2916 | + | |
| 2917 | + return 0; | |
| 2918 | +} | |
| 2919 | + | |
| 2903 | 2920 | static int check_subprogs(struct bpf_verifier_env *env) |
| 2904 | 2921 | { |
| 2905 | 2922 | int i, subprog_start, subprog_end, off, cur_subprog = 0; |
| @@ -20140,7 +20157,13 @@ int bpf_check(struct bpf_prog **prog, union bpf_attr *attr, bpfptr_t uattr, · 17234 unmodified lines | ||
| 20140 | 20157 | if (ret < 0) |
| 20141 | 20158 | goto skip_full_check; |
| 20142 | 20159 | |
| 20143 | − ret = add_subprog_and_kfunc(env); | |
| 20160 | + /* Discover all subprograms before validating their layout and BTF. */ | |
| 20161 | + ret = add_subprogs(env); | |
| 20162 | + if (ret < 0) | |
| 20163 | + goto skip_full_check; | |
| 20164 | + | |
| 20165 | + /* Collect the kfunc descriptors used during verification. */ | |
| 20166 | + ret = add_kfuncs(env); | |
| 20144 | 20167 | if (ret < 0) |
| 20145 | 20168 | goto skip_full_check; |
| 20146 | 20169 | |