diff options
Diffstat (limited to 'tools')
-rw-r--r-- | tools/bpf/bpftool/prog.c | 181 | ||||
-rw-r--r-- | tools/lib/bpf/libbpf.c | 5 | ||||
-rw-r--r-- | tools/testing/selftests/bpf/config | 1 | ||||
-rw-r--r-- | tools/testing/selftests/bpf/test_dev_cgroup.c | 9 | ||||
-rw-r--r-- | tools/testing/selftests/bpf/test_verifier.c | 241 |
5 files changed, 425 insertions, 12 deletions
diff --git a/tools/bpf/bpftool/prog.c b/tools/bpf/bpftool/prog.c index 037484ceaeaf..42ee8892549c 100644 --- a/tools/bpf/bpftool/prog.c +++ b/tools/bpf/bpftool/prog.c @@ -401,6 +401,88 @@ static int do_show(int argc, char **argv) return err; } +#define SYM_MAX_NAME 256 + +struct kernel_sym { + unsigned long address; + char name[SYM_MAX_NAME]; +}; + +struct dump_data { + unsigned long address_call_base; + struct kernel_sym *sym_mapping; + __u32 sym_count; + char scratch_buff[SYM_MAX_NAME]; +}; + +static int kernel_syms_cmp(const void *sym_a, const void *sym_b) +{ + return ((struct kernel_sym *)sym_a)->address - + ((struct kernel_sym *)sym_b)->address; +} + +static void kernel_syms_load(struct dump_data *dd) +{ + struct kernel_sym *sym; + char buff[256]; + void *tmp, *address; + FILE *fp; + + fp = fopen("/proc/kallsyms", "r"); + if (!fp) + return; + + while (!feof(fp)) { + if (!fgets(buff, sizeof(buff), fp)) + break; + tmp = realloc(dd->sym_mapping, + (dd->sym_count + 1) * + sizeof(*dd->sym_mapping)); + if (!tmp) { +out: + free(dd->sym_mapping); + dd->sym_mapping = NULL; + fclose(fp); + return; + } + dd->sym_mapping = tmp; + sym = &dd->sym_mapping[dd->sym_count]; + if (sscanf(buff, "%p %*c %s", &address, sym->name) != 2) + continue; + sym->address = (unsigned long)address; + if (!strcmp(sym->name, "__bpf_call_base")) { + dd->address_call_base = sym->address; + /* sysctl kernel.kptr_restrict was set */ + if (!sym->address) + goto out; + } + if (sym->address) + dd->sym_count++; + } + + fclose(fp); + + qsort(dd->sym_mapping, dd->sym_count, + sizeof(*dd->sym_mapping), kernel_syms_cmp); +} + +static void kernel_syms_destroy(struct dump_data *dd) +{ + free(dd->sym_mapping); +} + +static struct kernel_sym *kernel_syms_search(struct dump_data *dd, + unsigned long key) +{ + struct kernel_sym sym = { + .address = key, + }; + + return dd->sym_mapping ? + bsearch(&sym, dd->sym_mapping, dd->sym_count, + sizeof(*dd->sym_mapping), kernel_syms_cmp) : NULL; +} + static void print_insn(struct bpf_verifier_env *env, const char *fmt, ...) { va_list args; @@ -410,8 +492,71 @@ static void print_insn(struct bpf_verifier_env *env, const char *fmt, ...) va_end(args); } -static void dump_xlated_plain(void *buf, unsigned int len, bool opcodes) +static const char *print_call_pcrel(struct dump_data *dd, + struct kernel_sym *sym, + unsigned long address, + const struct bpf_insn *insn) { + if (sym) + snprintf(dd->scratch_buff, sizeof(dd->scratch_buff), + "%+d#%s", insn->off, sym->name); + else + snprintf(dd->scratch_buff, sizeof(dd->scratch_buff), + "%+d#0x%lx", insn->off, address); + return dd->scratch_buff; +} + +static const char *print_call_helper(struct dump_data *dd, + struct kernel_sym *sym, + unsigned long address) +{ + if (sym) + snprintf(dd->scratch_buff, sizeof(dd->scratch_buff), + "%s", sym->name); + else + snprintf(dd->scratch_buff, sizeof(dd->scratch_buff), + "0x%lx", address); + return dd->scratch_buff; +} + +static const char *print_call(void *private_data, + const struct bpf_insn *insn) +{ + struct dump_data *dd = private_data; + unsigned long address = dd->address_call_base + insn->imm; + struct kernel_sym *sym; + + sym = kernel_syms_search(dd, address); + if (insn->src_reg == BPF_PSEUDO_CALL) + return print_call_pcrel(dd, sym, address, insn); + else + return print_call_helper(dd, sym, address); +} + +static const char *print_imm(void *private_data, + const struct bpf_insn *insn, + __u64 full_imm) +{ + struct dump_data *dd = private_data; + + if (insn->src_reg == BPF_PSEUDO_MAP_FD) + snprintf(dd->scratch_buff, sizeof(dd->scratch_buff), + "map[id:%u]", insn->imm); + else + snprintf(dd->scratch_buff, sizeof(dd->scratch_buff), + "0x%llx", (unsigned long long)full_imm); + return dd->scratch_buff; +} + +static void dump_xlated_plain(struct dump_data *dd, void *buf, + unsigned int len, bool opcodes) +{ + const struct bpf_insn_cbs cbs = { + .cb_print = print_insn, + .cb_call = print_call, + .cb_imm = print_imm, + .private_data = dd, + }; struct bpf_insn *insn = buf; bool double_insn = false; unsigned int i; @@ -425,7 +570,7 @@ static void dump_xlated_plain(void *buf, unsigned int len, bool opcodes) double_insn = insn[i].code == (BPF_LD | BPF_IMM | BPF_DW); printf("% 4d: ", i); - print_bpf_insn(print_insn, NULL, insn + i, true); + print_bpf_insn(&cbs, NULL, insn + i, true); if (opcodes) { printf(" "); @@ -454,8 +599,15 @@ static void print_insn_json(struct bpf_verifier_env *env, const char *fmt, ...) va_end(args); } -static void dump_xlated_json(void *buf, unsigned int len, bool opcodes) +static void dump_xlated_json(struct dump_data *dd, void *buf, + unsigned int len, bool opcodes) { + const struct bpf_insn_cbs cbs = { + .cb_print = print_insn_json, + .cb_call = print_call, + .cb_imm = print_imm, + .private_data = dd, + }; struct bpf_insn *insn = buf; bool double_insn = false; unsigned int i; @@ -470,7 +622,7 @@ static void dump_xlated_json(void *buf, unsigned int len, bool opcodes) jsonw_start_object(json_wtr); jsonw_name(json_wtr, "disasm"); - print_bpf_insn(print_insn_json, NULL, insn + i, true); + print_bpf_insn(&cbs, NULL, insn + i, true); if (opcodes) { jsonw_name(json_wtr, "opcodes"); @@ -505,6 +657,7 @@ static void dump_xlated_json(void *buf, unsigned int len, bool opcodes) static int do_dump(int argc, char **argv) { struct bpf_prog_info info = {}; + struct dump_data dd = {}; __u32 len = sizeof(info); unsigned int buf_size; char *filepath = NULL; @@ -592,6 +745,14 @@ static int do_dump(int argc, char **argv) goto err_free; } + if ((member_len == &info.jited_prog_len && + info.jited_prog_insns == 0) || + (member_len == &info.xlated_prog_len && + info.xlated_prog_insns == 0)) { + p_err("error retrieving insn dump: kernel.kptr_restrict set?"); + goto err_free; + } + if (filepath) { fd = open(filepath, O_WRONLY | O_CREAT | O_TRUNC, 0600); if (fd < 0) { @@ -608,17 +769,19 @@ static int do_dump(int argc, char **argv) goto err_free; } } else { - if (member_len == &info.jited_prog_len) + if (member_len == &info.jited_prog_len) { disasm_print_insn(buf, *member_len, opcodes); - else + } else { + kernel_syms_load(&dd); if (json_output) - dump_xlated_json(buf, *member_len, opcodes); + dump_xlated_json(&dd, buf, *member_len, opcodes); else - dump_xlated_plain(buf, *member_len, opcodes); + dump_xlated_plain(&dd, buf, *member_len, opcodes); + kernel_syms_destroy(&dd); + } } free(buf); - return 0; err_free: diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 5b83875b3594..e9c4b7cabcf2 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -910,8 +910,9 @@ bpf_program__collect_reloc(struct bpf_program *prog, GElf_Shdr *shdr, GELF_R_SYM(rel.r_info)); return -LIBBPF_ERRNO__FORMAT; } - pr_debug("relo for %ld value %ld name %d\n", - rel.r_info >> 32, sym.st_value, sym.st_name); + pr_debug("relo for %lld value %lld name %d\n", + (long long) (rel.r_info >> 32), + (long long) sym.st_value, sym.st_name); if (sym.st_shndx != maps_shndx && sym.st_shndx != text_shndx) { pr_warning("Program '%s' contains non-map related relo data pointing to section %u\n", diff --git a/tools/testing/selftests/bpf/config b/tools/testing/selftests/bpf/config index 9d4897317c77..983dd25d49f4 100644 --- a/tools/testing/selftests/bpf/config +++ b/tools/testing/selftests/bpf/config @@ -4,3 +4,4 @@ CONFIG_NET_CLS_BPF=m CONFIG_BPF_EVENTS=y CONFIG_TEST_BPF=m CONFIG_CGROUP_BPF=y +CONFIG_NETDEVSIM=m diff --git a/tools/testing/selftests/bpf/test_dev_cgroup.c b/tools/testing/selftests/bpf/test_dev_cgroup.c index 02c85d6c89b0..c1535b34f14f 100644 --- a/tools/testing/selftests/bpf/test_dev_cgroup.c +++ b/tools/testing/selftests/bpf/test_dev_cgroup.c @@ -10,6 +10,8 @@ #include <string.h> #include <errno.h> #include <assert.h> +#include <sys/time.h> +#include <sys/resource.h> #include <linux/bpf.h> #include <bpf/bpf.h> @@ -23,15 +25,19 @@ int main(int argc, char **argv) { + struct rlimit limit = { RLIM_INFINITY, RLIM_INFINITY }; struct bpf_object *obj; int error = EXIT_FAILURE; int prog_fd, cgroup_fd; __u32 prog_cnt; + if (setrlimit(RLIMIT_MEMLOCK, &limit) < 0) + perror("Unable to lift memlock rlimit"); + if (bpf_prog_load(DEV_CGROUP_PROG, BPF_PROG_TYPE_CGROUP_DEVICE, &obj, &prog_fd)) { printf("Failed to load DEV_CGROUP program\n"); - goto err; + goto out; } if (setup_cgroup_environment()) { @@ -89,5 +95,6 @@ int main(int argc, char **argv) err: cleanup_cgroup_environment(); +out: return error; } diff --git a/tools/testing/selftests/bpf/test_verifier.c b/tools/testing/selftests/bpf/test_verifier.c index d38334abb990..543847957fdd 100644 --- a/tools/testing/selftests/bpf/test_verifier.c +++ b/tools/testing/selftests/bpf/test_verifier.c @@ -9273,6 +9273,196 @@ static struct bpf_test tests[] = { .result = ACCEPT, }, { + "calls: stack overflow using two frames (pre-call access)", + .insns = { + /* prog 1 */ + BPF_ST_MEM(BPF_B, BPF_REG_10, -300, 0), + BPF_RAW_INSN(BPF_JMP|BPF_CALL, 0, 1, 0, 1), + BPF_EXIT_INSN(), + + /* prog 2 */ + BPF_ST_MEM(BPF_B, BPF_REG_10, -300, 0), + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_XDP, + .errstr = "combined stack size", + .result = REJECT, + }, + { + "calls: stack overflow using two frames (post-call access)", + .insns = { + /* prog 1 */ + BPF_RAW_INSN(BPF_JMP|BPF_CALL, 0, 1, 0, 2), + BPF_ST_MEM(BPF_B, BPF_REG_10, -300, 0), + BPF_EXIT_INSN(), + + /* prog 2 */ + BPF_ST_MEM(BPF_B, BPF_REG_10, -300, 0), + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_XDP, + .errstr = "combined stack size", + .result = REJECT, + }, + { + "calls: stack depth check using three frames. test1", + .insns = { + /* main */ + BPF_RAW_INSN(BPF_JMP|BPF_CALL, 0, 1, 0, 4), /* call A */ + BPF_RAW_INSN(BPF_JMP|BPF_CALL, 0, 1, 0, 5), /* call B */ + BPF_ST_MEM(BPF_B, BPF_REG_10, -32, 0), + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + /* A */ + BPF_ST_MEM(BPF_B, BPF_REG_10, -256, 0), + BPF_EXIT_INSN(), + /* B */ + BPF_RAW_INSN(BPF_JMP|BPF_CALL, 0, 1, 0, -3), /* call A */ + BPF_ST_MEM(BPF_B, BPF_REG_10, -64, 0), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_XDP, + /* stack_main=32, stack_A=256, stack_B=64 + * and max(main+A, main+A+B) < 512 + */ + .result = ACCEPT, + }, + { + "calls: stack depth check using three frames. test2", + .insns = { + /* main */ + BPF_RAW_INSN(BPF_JMP|BPF_CALL, 0, 1, 0, 4), /* call A */ + BPF_RAW_INSN(BPF_JMP|BPF_CALL, 0, 1, 0, 5), /* call B */ + BPF_ST_MEM(BPF_B, BPF_REG_10, -32, 0), + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + /* A */ + BPF_ST_MEM(BPF_B, BPF_REG_10, -64, 0), + BPF_EXIT_INSN(), + /* B */ + BPF_RAW_INSN(BPF_JMP|BPF_CALL, 0, 1, 0, -3), /* call A */ + BPF_ST_MEM(BPF_B, BPF_REG_10, -256, 0), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_XDP, + /* stack_main=32, stack_A=64, stack_B=256 + * and max(main+A, main+A+B) < 512 + */ + .result = ACCEPT, + }, + { + "calls: stack depth check using three frames. test3", + .insns = { + /* main */ + BPF_MOV64_REG(BPF_REG_6, BPF_REG_1), + BPF_RAW_INSN(BPF_JMP|BPF_CALL, 0, 1, 0, 6), /* call A */ + BPF_MOV64_REG(BPF_REG_1, BPF_REG_6), + BPF_RAW_INSN(BPF_JMP|BPF_CALL, 0, 1, 0, 8), /* call B */ + BPF_JMP_IMM(BPF_JGE, BPF_REG_6, 0, 1), + BPF_ST_MEM(BPF_B, BPF_REG_10, -64, 0), + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + /* A */ + BPF_JMP_IMM(BPF_JLT, BPF_REG_1, 10, 1), + BPF_EXIT_INSN(), + BPF_ST_MEM(BPF_B, BPF_REG_10, -224, 0), + BPF_JMP_IMM(BPF_JA, 0, 0, -3), + /* B */ + BPF_JMP_IMM(BPF_JGT, BPF_REG_1, 2, 1), + BPF_RAW_INSN(BPF_JMP|BPF_CALL, 0, 1, 0, -6), /* call A */ + BPF_ST_MEM(BPF_B, BPF_REG_10, -256, 0), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_XDP, + /* stack_main=64, stack_A=224, stack_B=256 + * and max(main+A, main+A+B) > 512 + */ + .errstr = "combined stack", + .result = REJECT, + }, + { + "calls: stack depth check using three frames. test4", + /* void main(void) { + * func1(0); + * func1(1); + * func2(1); + * } + * void func1(int alloc_or_recurse) { + * if (alloc_or_recurse) { + * frame_pointer[-300] = 1; + * } else { + * func2(alloc_or_recurse); + * } + * } + * void func2(int alloc_or_recurse) { + * if (alloc_or_recurse) { + * frame_pointer[-300] = 1; + * } + * } + */ + .insns = { + /* main */ + BPF_MOV64_IMM(BPF_REG_1, 0), + BPF_RAW_INSN(BPF_JMP|BPF_CALL, 0, 1, 0, 6), /* call A */ + BPF_MOV64_IMM(BPF_REG_1, 1), + BPF_RAW_INSN(BPF_JMP|BPF_CALL, 0, 1, 0, 4), /* call A */ + BPF_MOV64_IMM(BPF_REG_1, 1), + BPF_RAW_INSN(BPF_JMP|BPF_CALL, 0, 1, 0, 7), /* call B */ + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + /* A */ + BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 0, 2), + BPF_ST_MEM(BPF_B, BPF_REG_10, -300, 0), + BPF_EXIT_INSN(), + BPF_RAW_INSN(BPF_JMP|BPF_CALL, 0, 1, 0, 1), /* call B */ + BPF_EXIT_INSN(), + /* B */ + BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 0, 1), + BPF_ST_MEM(BPF_B, BPF_REG_10, -300, 0), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_XDP, + .result = REJECT, + .errstr = "combined stack", + }, + { + "calls: stack depth check using three frames. test5", + .insns = { + /* main */ + BPF_RAW_INSN(BPF_JMP|BPF_CALL, 0, 1, 0, 1), /* call A */ + BPF_EXIT_INSN(), + /* A */ + BPF_RAW_INSN(BPF_JMP|BPF_CALL, 0, 1, 0, 1), /* call B */ + BPF_EXIT_INSN(), + /* B */ + BPF_RAW_INSN(BPF_JMP|BPF_CALL, 0, 1, 0, 1), /* call C */ + BPF_EXIT_INSN(), + /* C */ + BPF_RAW_INSN(BPF_JMP|BPF_CALL, 0, 1, 0, 1), /* call D */ + BPF_EXIT_INSN(), + /* D */ + BPF_RAW_INSN(BPF_JMP|BPF_CALL, 0, 1, 0, 1), /* call E */ + BPF_EXIT_INSN(), + /* E */ + BPF_RAW_INSN(BPF_JMP|BPF_CALL, 0, 1, 0, 1), /* call F */ + BPF_EXIT_INSN(), + /* F */ + BPF_RAW_INSN(BPF_JMP|BPF_CALL, 0, 1, 0, 1), /* call G */ + BPF_EXIT_INSN(), + /* G */ + BPF_RAW_INSN(BPF_JMP|BPF_CALL, 0, 1, 0, 1), /* call H */ + BPF_EXIT_INSN(), + /* H */ + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_XDP, + .errstr = "call stack", + .result = REJECT, + }, + { "calls: spill into caller stack frame", .insns = { BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0), @@ -10258,6 +10448,57 @@ static struct bpf_test tests[] = { .result = REJECT, .prog_type = BPF_PROG_TYPE_XDP, }, + { + "search pruning: all branches should be verified (nop operation)", + .insns = { + BPF_MOV64_REG(BPF_REG_2, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8), + BPF_ST_MEM(BPF_DW, BPF_REG_2, 0, 0), + BPF_LD_MAP_FD(BPF_REG_1, 0), + BPF_EMIT_CALL(BPF_FUNC_map_lookup_elem), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 11), + BPF_LDX_MEM(BPF_DW, BPF_REG_3, BPF_REG_0, 0), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_3, 0xbeef, 2), + BPF_MOV64_IMM(BPF_REG_4, 0), + BPF_JMP_A(1), + BPF_MOV64_IMM(BPF_REG_4, 1), + BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_4, -16), + BPF_EMIT_CALL(BPF_FUNC_ktime_get_ns), + BPF_LDX_MEM(BPF_DW, BPF_REG_5, BPF_REG_10, -16), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_5, 0, 2), + BPF_MOV64_IMM(BPF_REG_6, 0), + BPF_ST_MEM(BPF_DW, BPF_REG_6, 0, 0xdead), + BPF_EXIT_INSN(), + }, + .fixup_map1 = { 3 }, + .errstr = "R6 invalid mem access 'inv'", + .result = REJECT, + .prog_type = BPF_PROG_TYPE_TRACEPOINT, + }, + { + "search pruning: all branches should be verified (invalid stack access)", + .insns = { + BPF_MOV64_REG(BPF_REG_2, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8), + BPF_ST_MEM(BPF_DW, BPF_REG_2, 0, 0), + BPF_LD_MAP_FD(BPF_REG_1, 0), + BPF_EMIT_CALL(BPF_FUNC_map_lookup_elem), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 8), + BPF_LDX_MEM(BPF_DW, BPF_REG_3, BPF_REG_0, 0), + BPF_MOV64_IMM(BPF_REG_4, 0), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_3, 0xbeef, 2), + BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_4, -16), + BPF_JMP_A(1), + BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_4, -24), + BPF_EMIT_CALL(BPF_FUNC_ktime_get_ns), + BPF_LDX_MEM(BPF_DW, BPF_REG_5, BPF_REG_10, -16), + BPF_EXIT_INSN(), + }, + .fixup_map1 = { 3 }, + .errstr = "invalid read from stack off -16+0 size 8", + .result = REJECT, + .prog_type = BPF_PROG_TYPE_TRACEPOINT, + }, }; static int probe_filter_length(const struct bpf_insn *fp) |