diff options
Diffstat (limited to 'kernel/bpf/core.c')
-rw-r--r-- | kernel/bpf/core.c | 186 |
1 files changed, 159 insertions, 27 deletions
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c index f93ed667546f..5cdd8da0e7f2 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -105,6 +105,91 @@ struct bpf_prog *bpf_prog_alloc(unsigned int size, gfp_t gfp_extra_flags) } EXPORT_SYMBOL_GPL(bpf_prog_alloc); +int bpf_prog_alloc_jited_linfo(struct bpf_prog *prog) +{ + if (!prog->aux->nr_linfo || !prog->jit_requested) + return 0; + + prog->aux->jited_linfo = kcalloc(prog->aux->nr_linfo, + sizeof(*prog->aux->jited_linfo), + GFP_KERNEL | __GFP_NOWARN); + if (!prog->aux->jited_linfo) + return -ENOMEM; + + return 0; +} + +void bpf_prog_free_jited_linfo(struct bpf_prog *prog) +{ + kfree(prog->aux->jited_linfo); + prog->aux->jited_linfo = NULL; +} + +void bpf_prog_free_unused_jited_linfo(struct bpf_prog *prog) +{ + if (prog->aux->jited_linfo && !prog->aux->jited_linfo[0]) + bpf_prog_free_jited_linfo(prog); +} + +/* The jit engine is responsible to provide an array + * for insn_off to the jited_off mapping (insn_to_jit_off). + * + * The idx to this array is the insn_off. Hence, the insn_off + * here is relative to the prog itself instead of the main prog. + * This array has one entry for each xlated bpf insn. + * + * jited_off is the byte off to the last byte of the jited insn. + * + * Hence, with + * insn_start: + * The first bpf insn off of the prog. The insn off + * here is relative to the main prog. + * e.g. if prog is a subprog, insn_start > 0 + * linfo_idx: + * The prog's idx to prog->aux->linfo and jited_linfo + * + * jited_linfo[linfo_idx] = prog->bpf_func + * + * For i > linfo_idx, + * + * jited_linfo[i] = prog->bpf_func + + * insn_to_jit_off[linfo[i].insn_off - insn_start - 1] + */ +void bpf_prog_fill_jited_linfo(struct bpf_prog *prog, + const u32 *insn_to_jit_off) +{ + u32 linfo_idx, insn_start, insn_end, nr_linfo, i; + const struct bpf_line_info *linfo; + void **jited_linfo; + + if (!prog->aux->jited_linfo) + /* Userspace did not provide linfo */ + return; + + linfo_idx = prog->aux->linfo_idx; + linfo = &prog->aux->linfo[linfo_idx]; + insn_start = linfo[0].insn_off; + insn_end = insn_start + prog->len; + + jited_linfo = &prog->aux->jited_linfo[linfo_idx]; + jited_linfo[0] = prog->bpf_func; + + nr_linfo = prog->aux->nr_linfo - linfo_idx; + + for (i = 1; i < nr_linfo && linfo[i].insn_off < insn_end; i++) + /* The verifier ensures that linfo[i].insn_off is + * strictly increasing + */ + jited_linfo[i] = prog->bpf_func + + insn_to_jit_off[linfo[i].insn_off - insn_start - 1]; +} + +void bpf_prog_free_linfo(struct bpf_prog *prog) +{ + bpf_prog_free_jited_linfo(prog); + kvfree(prog->aux->linfo); +} + struct bpf_prog *bpf_prog_realloc(struct bpf_prog *fp_old, unsigned int size, gfp_t gfp_extra_flags) { @@ -294,6 +379,26 @@ static int bpf_adj_branches(struct bpf_prog *prog, u32 pos, u32 delta, return ret; } +static void bpf_adj_linfo(struct bpf_prog *prog, u32 off, u32 delta) +{ + struct bpf_line_info *linfo; + u32 i, nr_linfo; + + nr_linfo = prog->aux->nr_linfo; + if (!nr_linfo || !delta) + return; + + linfo = prog->aux->linfo; + + for (i = 0; i < nr_linfo; i++) + if (off < linfo[i].insn_off) + break; + + /* Push all off < linfo[i].insn_off by delta */ + for (; i < nr_linfo; i++) + linfo[i].insn_off += delta; +} + struct bpf_prog *bpf_patch_insn_single(struct bpf_prog *prog, u32 off, const struct bpf_insn *patch, u32 len) { @@ -349,6 +454,8 @@ struct bpf_prog *bpf_patch_insn_single(struct bpf_prog *prog, u32 off, */ BUG_ON(bpf_adj_branches(prog_adj, off, insn_delta, false)); + bpf_adj_linfo(prog_adj, off, insn_delta); + return prog_adj; } @@ -410,7 +517,7 @@ static void bpf_get_prog_name(const struct bpf_prog *prog, char *sym) sym = bin2hex(sym, prog->tag, sizeof(prog->tag)); /* prog->aux->name will be ignored if full btf name is available */ - if (prog->aux->btf) { + if (prog->aux->func_info_cnt) { type = btf_type_by_id(prog->aux->btf, prog->aux->func_info[prog->aux->func_idx].type_id); func_name = btf_name_by_offset(prog->aux->btf, type->name_off); @@ -623,6 +730,16 @@ static void bpf_jit_uncharge_modmem(u32 pages) atomic_long_sub(pages, &bpf_jit_current); } +void *__weak bpf_jit_alloc_exec(unsigned long size) +{ + return module_alloc(size); +} + +void __weak bpf_jit_free_exec(void *addr) +{ + module_memfree(addr); +} + struct bpf_binary_header * bpf_jit_binary_alloc(unsigned int proglen, u8 **image_ptr, unsigned int alignment, @@ -640,7 +757,7 @@ bpf_jit_binary_alloc(unsigned int proglen, u8 **image_ptr, if (bpf_jit_charge_modmem(pages)) return NULL; - hdr = module_alloc(size); + hdr = bpf_jit_alloc_exec(size); if (!hdr) { bpf_jit_uncharge_modmem(pages); return NULL; @@ -664,7 +781,7 @@ void bpf_jit_binary_free(struct bpf_binary_header *hdr) { u32 pages = hdr->pages; - module_memfree(hdr); + bpf_jit_free_exec(hdr); bpf_jit_uncharge_modmem(pages); } @@ -923,32 +1040,34 @@ EXPORT_SYMBOL_GPL(__bpf_call_base); #define BPF_INSN_MAP(INSN_2, INSN_3) \ /* 32 bit ALU operations. */ \ /* Register based. */ \ - INSN_3(ALU, ADD, X), \ - INSN_3(ALU, SUB, X), \ - INSN_3(ALU, AND, X), \ - INSN_3(ALU, OR, X), \ - INSN_3(ALU, LSH, X), \ - INSN_3(ALU, RSH, X), \ - INSN_3(ALU, XOR, X), \ - INSN_3(ALU, MUL, X), \ - INSN_3(ALU, MOV, X), \ - INSN_3(ALU, DIV, X), \ - INSN_3(ALU, MOD, X), \ + INSN_3(ALU, ADD, X), \ + INSN_3(ALU, SUB, X), \ + INSN_3(ALU, AND, X), \ + INSN_3(ALU, OR, X), \ + INSN_3(ALU, LSH, X), \ + INSN_3(ALU, RSH, X), \ + INSN_3(ALU, XOR, X), \ + INSN_3(ALU, MUL, X), \ + INSN_3(ALU, MOV, X), \ + INSN_3(ALU, ARSH, X), \ + INSN_3(ALU, DIV, X), \ + INSN_3(ALU, MOD, X), \ INSN_2(ALU, NEG), \ INSN_3(ALU, END, TO_BE), \ INSN_3(ALU, END, TO_LE), \ /* Immediate based. */ \ - INSN_3(ALU, ADD, K), \ - INSN_3(ALU, SUB, K), \ - INSN_3(ALU, AND, K), \ - INSN_3(ALU, OR, K), \ - INSN_3(ALU, LSH, K), \ - INSN_3(ALU, RSH, K), \ - INSN_3(ALU, XOR, K), \ - INSN_3(ALU, MUL, K), \ - INSN_3(ALU, MOV, K), \ - INSN_3(ALU, DIV, K), \ - INSN_3(ALU, MOD, K), \ + INSN_3(ALU, ADD, K), \ + INSN_3(ALU, SUB, K), \ + INSN_3(ALU, AND, K), \ + INSN_3(ALU, OR, K), \ + INSN_3(ALU, LSH, K), \ + INSN_3(ALU, RSH, K), \ + INSN_3(ALU, XOR, K), \ + INSN_3(ALU, MUL, K), \ + INSN_3(ALU, MOV, K), \ + INSN_3(ALU, ARSH, K), \ + INSN_3(ALU, DIV, K), \ + INSN_3(ALU, MOD, K), \ /* 64 bit ALU operations. */ \ /* Register based. */ \ INSN_3(ALU64, ADD, X), \ @@ -1127,6 +1246,12 @@ select_insn: DST = (u64) (u32) insn[0].imm | ((u64) (u32) insn[1].imm) << 32; insn++; CONT; + ALU_ARSH_X: + DST = (u64) (u32) ((*(s32 *) &DST) >> SRC); + CONT; + ALU_ARSH_K: + DST = (u64) (u32) ((*(s32 *) &DST) >> IMM); + CONT; ALU64_ARSH_X: (*(s64 *) &DST) >>= SRC; CONT; @@ -1573,13 +1698,20 @@ struct bpf_prog *bpf_prog_select_runtime(struct bpf_prog *fp, int *err) * be JITed, but falls back to the interpreter. */ if (!bpf_prog_is_dev_bound(fp->aux)) { + *err = bpf_prog_alloc_jited_linfo(fp); + if (*err) + return fp; + fp = bpf_int_jit_compile(fp); -#ifdef CONFIG_BPF_JIT_ALWAYS_ON if (!fp->jited) { + bpf_prog_free_jited_linfo(fp); +#ifdef CONFIG_BPF_JIT_ALWAYS_ON *err = -ENOTSUPP; return fp; - } #endif + } else { + bpf_prog_free_unused_jited_linfo(fp); + } } else { *err = bpf_prog_offload_compile(fp); if (*err) |