diff options
| author | Jakub Kicinski <kuba@kernel.org> | 2021-11-01 19:59:45 -0700 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2021-11-01 19:59:46 -0700 |
| commit | b7b98f868987cd3e86c9bd9a6db048614933d7a0 (patch) | |
| tree | 8651e9d44726348ea56692d988b26c273e129c7a /tools/lib/bpf/gen_loader.c | |
| parent | 52fa3ee0cce60a04739f4a5ca1c9d5c2a8ee1578 (diff) | |
| parent | 0b170456e0dda92b8925d40e217461fcc4e1efc9 (diff) | |
| download | linux-b7b98f868987cd3e86c9bd9a6db048614933d7a0.tar.gz linux-b7b98f868987cd3e86c9bd9a6db048614933d7a0.tar.bz2 linux-b7b98f868987cd3e86c9bd9a6db048614933d7a0.zip | |
Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Alexei Starovoitov says:
====================
pull-request: bpf-next 2021-11-01
We've added 181 non-merge commits during the last 28 day(s) which contain
a total of 280 files changed, 11791 insertions(+), 5879 deletions(-).
The main changes are:
1) Fix bpf verifier propagation of 64-bit bounds, from Alexei.
2) Parallelize bpf test_progs, from Yucong and Andrii.
3) Deprecate various libbpf apis including af_xdp, from Andrii, Hengqi, Magnus.
4) Improve bpf selftests on s390, from Ilya.
5) bloomfilter bpf map type, from Joanne.
6) Big improvements to JIT tests especially on Mips, from Johan.
7) Support kernel module function calls from bpf, from Kumar.
8) Support typeless and weak ksym in light skeleton, from Kumar.
9) Disallow unprivileged bpf by default, from Pawan.
10) BTF_KIND_DECL_TAG support, from Yonghong.
11) Various bpftool cleanups, from Quentin.
* https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (181 commits)
libbpf: Deprecate AF_XDP support
kbuild: Unify options for BTF generation for vmlinux and modules
selftests/bpf: Add a testcase for 64-bit bounds propagation issue.
bpf: Fix propagation of signed bounds from 64-bit min/max into 32-bit.
bpf: Fix propagation of bounds from 64-bit min/max into 32-bit and var_off.
selftests/bpf: Fix also no-alu32 strobemeta selftest
bpf: Add missing map_delete_elem method to bloom filter map
selftests/bpf: Add bloom map success test for userspace calls
bpf: Add alignment padding for "map_extra" + consolidate holes
bpf: Bloom filter map naming fixups
selftests/bpf: Add test cases for struct_ops prog
bpf: Add dummy BPF STRUCT_OPS for test purpose
bpf: Factor out helpers for ctx access checking
bpf: Factor out a helper to prepare trampoline for struct_ops prog
selftests, bpf: Fix broken riscv build
riscv, libbpf: Add RISC-V (RV64) support to bpf_tracing.h
tools, build: Add RISC-V to HOSTARCH parsing
riscv, bpf: Increase the maximum number of iterations
selftests, bpf: Add one test for sockmap with strparser
selftests, bpf: Fix test_txmsg_ingress_parser error
...
====================
Link: https://lore.kernel.org/r/20211102013123.9005-1-alexei.starovoitov@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'tools/lib/bpf/gen_loader.c')
| -rw-r--r-- | tools/lib/bpf/gen_loader.c | 419 |
1 files changed, 365 insertions, 54 deletions
diff --git a/tools/lib/bpf/gen_loader.c b/tools/lib/bpf/gen_loader.c index 80087b13877f..502dea53a742 100644 --- a/tools/lib/bpf/gen_loader.c +++ b/tools/lib/bpf/gen_loader.c @@ -13,9 +13,12 @@ #include "hashmap.h" #include "bpf_gen_internal.h" #include "skel_internal.h" +#include <asm/byteorder.h> -#define MAX_USED_MAPS 64 -#define MAX_USED_PROGS 32 +#define MAX_USED_MAPS 64 +#define MAX_USED_PROGS 32 +#define MAX_KFUNC_DESCS 256 +#define MAX_FD_ARRAY_SZ (MAX_USED_PROGS + MAX_KFUNC_DESCS) /* The following structure describes the stack layout of the loader program. * In addition R6 contains the pointer to context. @@ -30,7 +33,6 @@ */ struct loader_stack { __u32 btf_fd; - __u32 map_fd[MAX_USED_MAPS]; __u32 prog_fd[MAX_USED_PROGS]; __u32 inner_map_fd; }; @@ -143,13 +145,49 @@ static int add_data(struct bpf_gen *gen, const void *data, __u32 size) if (realloc_data_buf(gen, size8)) return 0; prev = gen->data_cur; - memcpy(gen->data_cur, data, size); - gen->data_cur += size; - memcpy(gen->data_cur, &zero, size8 - size); - gen->data_cur += size8 - size; + if (data) { + memcpy(gen->data_cur, data, size); + memcpy(gen->data_cur + size, &zero, size8 - size); + } else { + memset(gen->data_cur, 0, size8); + } + gen->data_cur += size8; return prev - gen->data_start; } +/* Get index for map_fd/btf_fd slot in reserved fd_array, or in data relative + * to start of fd_array. Caller can decide if it is usable or not. + */ +static int add_map_fd(struct bpf_gen *gen) +{ + if (!gen->fd_array) + gen->fd_array = add_data(gen, NULL, MAX_FD_ARRAY_SZ * sizeof(int)); + if (gen->nr_maps == MAX_USED_MAPS) { + pr_warn("Total maps exceeds %d\n", MAX_USED_MAPS); + gen->error = -E2BIG; + return 0; + } + return gen->nr_maps++; +} + +static int add_kfunc_btf_fd(struct bpf_gen *gen) +{ + int cur; + + if (!gen->fd_array) + gen->fd_array = add_data(gen, NULL, MAX_FD_ARRAY_SZ * sizeof(int)); + if (gen->nr_fd_array == MAX_KFUNC_DESCS) { + cur = add_data(gen, NULL, sizeof(int)); + return (cur - gen->fd_array) / sizeof(int); + } + return MAX_USED_MAPS + gen->nr_fd_array++; +} + +static int blob_fd_array_off(struct bpf_gen *gen, int index) +{ + return gen->fd_array + index * sizeof(int); +} + static int insn_bytes_to_bpf_size(__u32 sz) { switch (sz) { @@ -171,14 +209,22 @@ static void emit_rel_store(struct bpf_gen *gen, int off, int data) emit(gen, BPF_STX_MEM(BPF_DW, BPF_REG_1, BPF_REG_0, 0)); } -/* *(u64 *)(blob + off) = (u64)(void *)(%sp + stack_off) */ -static void emit_rel_store_sp(struct bpf_gen *gen, int off, int stack_off) +static void move_blob2blob(struct bpf_gen *gen, int off, int size, int blob_off) { - emit(gen, BPF_MOV64_REG(BPF_REG_0, BPF_REG_10)); - emit(gen, BPF_ALU64_IMM(BPF_ADD, BPF_REG_0, stack_off)); + emit2(gen, BPF_LD_IMM64_RAW_FULL(BPF_REG_2, BPF_PSEUDO_MAP_IDX_VALUE, + 0, 0, 0, blob_off)); + emit(gen, BPF_LDX_MEM(insn_bytes_to_bpf_size(size), BPF_REG_0, BPF_REG_2, 0)); emit2(gen, BPF_LD_IMM64_RAW_FULL(BPF_REG_1, BPF_PSEUDO_MAP_IDX_VALUE, 0, 0, 0, off)); - emit(gen, BPF_STX_MEM(BPF_DW, BPF_REG_1, BPF_REG_0, 0)); + emit(gen, BPF_STX_MEM(insn_bytes_to_bpf_size(size), BPF_REG_1, BPF_REG_0, 0)); +} + +static void move_blob2ctx(struct bpf_gen *gen, int ctx_off, int size, int blob_off) +{ + emit2(gen, BPF_LD_IMM64_RAW_FULL(BPF_REG_1, BPF_PSEUDO_MAP_IDX_VALUE, + 0, 0, 0, blob_off)); + emit(gen, BPF_LDX_MEM(insn_bytes_to_bpf_size(size), BPF_REG_0, BPF_REG_1, 0)); + emit(gen, BPF_STX_MEM(insn_bytes_to_bpf_size(size), BPF_REG_6, BPF_REG_0, ctx_off)); } static void move_ctx2blob(struct bpf_gen *gen, int off, int size, int ctx_off, @@ -326,11 +372,11 @@ int bpf_gen__finish(struct bpf_gen *gen) offsetof(struct bpf_prog_desc, prog_fd), 4, stack_off(prog_fd[i])); for (i = 0; i < gen->nr_maps; i++) - move_stack2ctx(gen, - sizeof(struct bpf_loader_ctx) + - sizeof(struct bpf_map_desc) * i + - offsetof(struct bpf_map_desc, map_fd), 4, - stack_off(map_fd[i])); + move_blob2ctx(gen, + sizeof(struct bpf_loader_ctx) + + sizeof(struct bpf_map_desc) * i + + offsetof(struct bpf_map_desc, map_fd), 4, + blob_fd_array_off(gen, i)); emit(gen, BPF_MOV64_IMM(BPF_REG_0, 0)); emit(gen, BPF_EXIT_INSN()); pr_debug("gen: finish %d\n", gen->error); @@ -386,11 +432,11 @@ void bpf_gen__load_btf(struct bpf_gen *gen, const void *btf_raw_data, } void bpf_gen__map_create(struct bpf_gen *gen, - struct bpf_create_map_attr *map_attr, int map_idx) + struct bpf_create_map_params *map_attr, int map_idx) { int attr_size = offsetofend(union bpf_attr, btf_vmlinux_value_type_id); bool close_inner_map_fd = false; - int map_create_attr; + int map_create_attr, idx; union bpf_attr attr; memset(&attr, 0, attr_size); @@ -398,6 +444,7 @@ void bpf_gen__map_create(struct bpf_gen *gen, attr.key_size = map_attr->key_size; attr.value_size = map_attr->value_size; attr.map_flags = map_attr->map_flags; + attr.map_extra = map_attr->map_extra; memcpy(attr.map_name, map_attr->name, min((unsigned)strlen(map_attr->name), BPF_OBJ_NAME_LEN - 1)); attr.numa_node = map_attr->numa_node; @@ -467,9 +514,11 @@ void bpf_gen__map_create(struct bpf_gen *gen, gen->error = -EDOM; /* internal bug */ return; } else { - emit(gen, BPF_STX_MEM(BPF_W, BPF_REG_10, BPF_REG_7, - stack_off(map_fd[map_idx]))); - gen->nr_maps++; + /* add_map_fd does gen->nr_maps++ */ + idx = add_map_fd(gen); + emit2(gen, BPF_LD_IMM64_RAW_FULL(BPF_REG_1, BPF_PSEUDO_MAP_IDX_VALUE, + 0, 0, 0, blob_fd_array_off(gen, idx))); + emit(gen, BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_7, 0)); } if (close_inner_map_fd) emit_sys_close_stack(gen, stack_off(inner_map_fd)); @@ -511,8 +560,8 @@ static void emit_find_attach_target(struct bpf_gen *gen) */ } -void bpf_gen__record_extern(struct bpf_gen *gen, const char *name, int kind, - int insn_idx) +void bpf_gen__record_extern(struct bpf_gen *gen, const char *name, bool is_weak, + bool is_typeless, int kind, int insn_idx) { struct ksym_relo_desc *relo; @@ -524,38 +573,292 @@ void bpf_gen__record_extern(struct bpf_gen *gen, const char *name, int kind, gen->relos = relo; relo += gen->relo_cnt; relo->name = name; + relo->is_weak = is_weak; + relo->is_typeless = is_typeless; relo->kind = kind; relo->insn_idx = insn_idx; gen->relo_cnt++; } -static void emit_relo(struct bpf_gen *gen, struct ksym_relo_desc *relo, int insns) +/* returns existing ksym_desc with ref incremented, or inserts a new one */ +static struct ksym_desc *get_ksym_desc(struct bpf_gen *gen, struct ksym_relo_desc *relo) { - int name, insn, len = strlen(relo->name) + 1; + struct ksym_desc *kdesc; - pr_debug("gen: emit_relo: %s at %d\n", relo->name, relo->insn_idx); - name = add_data(gen, relo->name, len); + for (int i = 0; i < gen->nr_ksyms; i++) { + if (!strcmp(gen->ksyms[i].name, relo->name)) { + gen->ksyms[i].ref++; + return &gen->ksyms[i]; + } + } + kdesc = libbpf_reallocarray(gen->ksyms, gen->nr_ksyms + 1, sizeof(*kdesc)); + if (!kdesc) { + gen->error = -ENOMEM; + return NULL; + } + gen->ksyms = kdesc; + kdesc = &gen->ksyms[gen->nr_ksyms++]; + kdesc->name = relo->name; + kdesc->kind = relo->kind; + kdesc->ref = 1; + kdesc->off = 0; + kdesc->insn = 0; + return kdesc; +} + +/* Overwrites BPF_REG_{0, 1, 2, 3, 4, 7} + * Returns result in BPF_REG_7 + */ +static void emit_bpf_find_by_name_kind(struct bpf_gen *gen, struct ksym_relo_desc *relo) +{ + int name_off, len = strlen(relo->name) + 1; + name_off = add_data(gen, relo->name, len); emit2(gen, BPF_LD_IMM64_RAW_FULL(BPF_REG_1, BPF_PSEUDO_MAP_IDX_VALUE, - 0, 0, 0, name)); + 0, 0, 0, name_off)); emit(gen, BPF_MOV64_IMM(BPF_REG_2, len)); emit(gen, BPF_MOV64_IMM(BPF_REG_3, relo->kind)); emit(gen, BPF_MOV64_IMM(BPF_REG_4, 0)); emit(gen, BPF_EMIT_CALL(BPF_FUNC_btf_find_by_name_kind)); emit(gen, BPF_MOV64_REG(BPF_REG_7, BPF_REG_0)); debug_ret(gen, "find_by_name_kind(%s,%d)", relo->name, relo->kind); - emit_check_err(gen); +} + +/* Overwrites BPF_REG_{0, 1, 2, 3, 4, 7} + * Returns result in BPF_REG_7 + * Returns u64 symbol addr in BPF_REG_9 + */ +static void emit_bpf_kallsyms_lookup_name(struct bpf_gen *gen, struct ksym_relo_desc *relo) +{ + int name_off, len = strlen(relo->name) + 1, res_off; + + name_off = add_data(gen, relo->name, len); + res_off = add_data(gen, NULL, 8); /* res is u64 */ + emit2(gen, BPF_LD_IMM64_RAW_FULL(BPF_REG_1, BPF_PSEUDO_MAP_IDX_VALUE, + 0, 0, 0, name_off)); + emit(gen, BPF_MOV64_IMM(BPF_REG_2, len)); + emit(gen, BPF_MOV64_IMM(BPF_REG_3, 0)); + emit2(gen, BPF_LD_IMM64_RAW_FULL(BPF_REG_4, BPF_PSEUDO_MAP_IDX_VALUE, + 0, 0, 0, res_off)); + emit(gen, BPF_MOV64_REG(BPF_REG_7, BPF_REG_4)); + emit(gen, BPF_EMIT_CALL(BPF_FUNC_kallsyms_lookup_name)); + emit(gen, BPF_LDX_MEM(BPF_DW, BPF_REG_9, BPF_REG_7, 0)); + emit(gen, BPF_MOV64_REG(BPF_REG_7, BPF_REG_0)); + debug_ret(gen, "kallsyms_lookup_name(%s,%d)", relo->name, relo->kind); +} + +/* Expects: + * BPF_REG_8 - pointer to instruction + * + * We need to reuse BTF fd for same symbol otherwise each relocation takes a new + * index, while kernel limits total kfunc BTFs to 256. For duplicate symbols, + * this would mean a new BTF fd index for each entry. By pairing symbol name + * with index, we get the insn->imm, insn->off pairing that kernel uses for + * kfunc_tab, which becomes the effective limit even though all of them may + * share same index in fd_array (such that kfunc_btf_tab has 1 element). + */ +static void emit_relo_kfunc_btf(struct bpf_gen *gen, struct ksym_relo_desc *relo, int insn) +{ + struct ksym_desc *kdesc; + int btf_fd_idx; + + kdesc = get_ksym_desc(gen, relo); + if (!kdesc) + return; + /* try to copy from existing bpf_insn */ + if (kdesc->ref > 1) { + move_blob2blob(gen, insn + offsetof(struct bpf_insn, imm), 4, + kdesc->insn + offsetof(struct bpf_insn, imm)); + move_blob2blob(gen, insn + offsetof(struct bpf_insn, off), 2, + kdesc->insn + offsetof(struct bpf_insn, off)); + goto log; + } + /* remember insn offset, so we can copy BTF ID and FD later */ + kdesc->insn = insn; + emit_bpf_find_by_name_kind(gen, relo); + if (!relo->is_weak) + emit_check_err(gen); + /* get index in fd_array to store BTF FD at */ + btf_fd_idx = add_kfunc_btf_fd(gen); + if (btf_fd_idx > INT16_MAX) { + pr_warn("BTF fd off %d for kfunc %s exceeds INT16_MAX, cannot process relocation\n", + btf_fd_idx, relo->name); + gen->error = -E2BIG; + return; + } + kdesc->off = btf_fd_idx; + /* set a default value for imm */ + emit(gen, BPF_ST_MEM(BPF_W, BPF_REG_8, offsetof(struct bpf_insn, imm), 0)); + /* skip success case store if ret < 0 */ + emit(gen, BPF_JMP_IMM(BPF_JSLT, BPF_REG_7, 0, 1)); /* store btf_id into insn[insn_idx].imm */ - insn = insns + sizeof(struct bpf_insn) * relo->insn_idx + - offsetof(struct bpf_insn, imm); + emit(gen, BPF_STX_MEM(BPF_W, BPF_REG_8, BPF_REG_7, offsetof(struct bpf_insn, imm))); + /* load fd_array slot pointer */ emit2(gen, BPF_LD_IMM64_RAW_FULL(BPF_REG_0, BPF_PSEUDO_MAP_IDX_VALUE, - 0, 0, 0, insn)); - emit(gen, BPF_STX_MEM(BPF_W, BPF_REG_0, BPF_REG_7, 0)); - if (relo->kind == BTF_KIND_VAR) { - /* store btf_obj_fd into insn[insn_idx + 1].imm */ - emit(gen, BPF_ALU64_IMM(BPF_RSH, BPF_REG_7, 32)); - emit(gen, BPF_STX_MEM(BPF_W, BPF_REG_0, BPF_REG_7, - sizeof(struct bpf_insn))); + 0, 0, 0, blob_fd_array_off(gen, btf_fd_idx))); + /* skip store of BTF fd if ret < 0 */ + emit(gen, BPF_JMP_IMM(BPF_JSLT, BPF_REG_7, 0, 3)); + /* store BTF fd in slot */ + emit(gen, BPF_MOV64_REG(BPF_REG_9, BPF_REG_7)); + emit(gen, BPF_ALU64_IMM(BPF_RSH, BPF_REG_9, 32)); + emit(gen, BPF_STX_MEM(BPF_W, BPF_REG_0, BPF_REG_9, 0)); + /* set a default value for off */ + emit(gen, BPF_ST_MEM(BPF_H, BPF_REG_8, offsetof(struct bpf_insn, off), 0)); + /* skip insn->off store if ret < 0 */ + emit(gen, BPF_JMP_IMM(BPF_JSLT, BPF_REG_7, 0, 2)); + /* skip if vmlinux BTF */ + emit(gen, BPF_JMP_IMM(BPF_JEQ, BPF_REG_9, 0, 1)); + /* store index into insn[insn_idx].off */ + emit(gen, BPF_ST_MEM(BPF_H, BPF_REG_8, offsetof(struct bpf_insn, off), btf_fd_idx)); +log: + if (!gen->log_level) + return; + emit(gen, BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_8, + offsetof(struct bpf_insn, imm))); + emit(gen, BPF_LDX_MEM(BPF_H, BPF_REG_9, BPF_REG_8, + offsetof(struct bpf_insn, off))); + debug_regs(gen, BPF_REG_7, BPF_REG_9, " func (%s:count=%d): imm: %%d, off: %%d", + relo->name, kdesc->ref); + emit2(gen, BPF_LD_IMM64_RAW_FULL(BPF_REG_0, BPF_PSEUDO_MAP_IDX_VALUE, + 0, 0, 0, blob_fd_array_off(gen, kdesc->off))); + emit(gen, BPF_LDX_MEM(BPF_W, BPF_REG_9, BPF_REG_0, 0)); + debug_regs(gen, BPF_REG_9, -1, " func (%s:count=%d): btf_fd", + relo->name, kdesc->ref); +} + +static void emit_ksym_relo_log(struct bpf_gen *gen, struct ksym_relo_desc *relo, + int ref) +{ + if (!gen->log_level) + return; + emit(gen, BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_8, + offsetof(struct bpf_insn, imm))); + emit(gen, BPF_LDX_MEM(BPF_H, BPF_REG_9, BPF_REG_8, sizeof(struct bpf_insn) + + offsetof(struct bpf_insn, imm))); + debug_regs(gen, BPF_REG_7, BPF_REG_9, " var t=%d w=%d (%s:count=%d): imm[0]: %%d, imm[1]: %%d", + relo->is_typeless, relo->is_weak, relo->name, ref); + emit(gen, BPF_LDX_MEM(BPF_B, BPF_REG_9, BPF_REG_8, offsetofend(struct bpf_insn, code))); + debug_regs(gen, BPF_REG_9, -1, " var t=%d w=%d (%s:count=%d): insn.reg", + relo->is_typeless, relo->is_weak, relo->name, ref); +} + +/* Expects: + * BPF_REG_8 - pointer to instruction + */ +static void emit_relo_ksym_typeless(struct bpf_gen *gen, + struct ksym_relo_desc *relo, int insn) +{ + struct ksym_desc *kdesc; + + kdesc = get_ksym_desc(gen, relo); + if (!kdesc) + return; + /* try to copy from existing ldimm64 insn */ + if (kdesc->ref > 1) { + move_blob2blob(gen, insn + offsetof(struct bpf_insn, imm), 4, + kdesc->insn + offsetof(struct bpf_insn, imm)); + move_blob2blob(gen, insn + sizeof(struct bpf_insn) + offsetof(struct bpf_insn, imm), 4, + kdesc->insn + sizeof(struct bpf_insn) + offsetof(struct bpf_insn, imm)); + goto log; + } + /* remember insn offset, so we can copy ksym addr later */ + kdesc->insn = insn; + /* skip typeless ksym_desc in fd closing loop in cleanup_relos */ + kdesc->typeless = true; + emit_bpf_kallsyms_lookup_name(gen, relo); + emit(gen, BPF_JMP_IMM(BPF_JEQ, BPF_REG_7, -ENOENT, 1)); + emit_check_err(gen); + /* store lower half of addr into insn[insn_idx].imm */ + emit(gen, BPF_STX_MEM(BPF_W, BPF_REG_8, BPF_REG_9, offsetof(struct bpf_insn, imm))); + /* store upper half of addr into insn[insn_idx + 1].imm */ + emit(gen, BPF_ALU64_IMM(BPF_RSH, BPF_REG_9, 32)); + emit(gen, BPF_STX_MEM(BPF_W, BPF_REG_8, BPF_REG_9, + sizeof(struct bpf_insn) + offsetof(struct bpf_insn, imm))); +log: + emit_ksym_relo_log(gen, relo, kdesc->ref); +} + +static __u32 src_reg_mask(void) +{ +#if defined(__LITTLE_ENDIAN_BITFIELD) + return 0x0f; /* src_reg,dst_reg,... */ +#elif defined(__BIG_ENDIAN_BITFIELD) + return 0xf0; /* dst_reg,src_reg,... */ +#else +#error "Unsupported bit endianness, cannot proceed" +#endif +} + +/* Expects: + * BPF_REG_8 - pointer to instruction + */ +static void emit_relo_ksym_btf(struct bpf_gen *gen, struct ksym_relo_desc *relo, int insn) +{ + struct ksym_desc *kdesc; + __u32 reg_mask; + + kdesc = get_ksym_desc(gen, relo); + if (!kdesc) + return; + /* try to copy from existing ldimm64 insn */ + if (kdesc->ref > 1) { + move_blob2blob(gen, insn + offsetof(struct bpf_insn, imm), 4, + kdesc->insn + offsetof(struct bpf_insn, imm)); + move_blob2blob(gen, insn + sizeof(struct bpf_insn) + offsetof(struct bpf_insn, imm), 4, + kdesc->insn + sizeof(struct bpf_insn) + offsetof(struct bpf_insn, imm)); + emit(gen, BPF_LDX_MEM(BPF_W, BPF_REG_9, BPF_REG_8, offsetof(struct bpf_insn, imm))); + /* jump over src_reg adjustment if imm is not 0 */ + emit(gen, BPF_JMP_IMM(BPF_JNE, BPF_REG_9, 0, 3)); + goto clear_src_reg; + } + /* remember insn offset, so we can copy BTF ID and FD later */ + kdesc->insn = insn; + emit_bpf_find_by_name_kind(gen, relo); + if (!relo->is_weak) + emit_check_err(gen); + /* set default values as 0 */ + emit(gen, BPF_ST_MEM(BPF_W, BPF_REG_8, offsetof(struct bpf_insn, imm), 0)); + emit(gen, BPF_ST_MEM(BPF_W, BPF_REG_8, sizeof(struct bpf_insn) + offsetof(struct bpf_insn, imm), 0)); + /* skip success case stores if ret < 0 */ + emit(gen, BPF_JMP_IMM(BPF_JSLT, BPF_REG_7, 0, 4)); + /* store btf_id into insn[insn_idx].imm */ + emit(gen, BPF_STX_MEM(BPF_W, BPF_REG_8, BPF_REG_7, offsetof(struct bpf_insn, imm))); + /* store btf_obj_fd into insn[insn_idx + 1].imm */ + emit(gen, BPF_ALU64_IMM(BPF_RSH, BPF_REG_7, 32)); + emit(gen, BPF_STX_MEM(BPF_W, BPF_REG_8, BPF_REG_7, + sizeof(struct bpf_insn) + offsetof(struct bpf_insn, imm))); + emit(gen, BPF_JMP_IMM(BPF_JSGE, BPF_REG_7, 0, 3)); +clear_src_reg: + /* clear bpf_object__relocate_data's src_reg assignment, otherwise we get a verifier failure */ + reg_mask = src_reg_mask(); + emit(gen, BPF_LDX_MEM(BPF_B, BPF_REG_9, BPF_REG_8, offsetofend(struct bpf_insn, code))); + emit(gen, BPF_ALU32_IMM(BPF_AND, BPF_REG_9, reg_mask)); + emit(gen, BPF_STX_MEM(BPF_B, BPF_REG_8, BPF_REG_9, offsetofend(struct bpf_insn, code))); + + emit_ksym_relo_log(gen, relo, kdesc->ref); +} + +static void emit_relo(struct bpf_gen *gen, struct ksym_relo_desc *relo, int insns) +{ + int insn; + + pr_debug("gen: emit_relo (%d): %s at %d\n", relo->kind, relo->name, relo->insn_idx); + insn = insns + sizeof(struct bpf_insn) * relo->insn_idx; + emit2(gen, BPF_LD_IMM64_RAW_FULL(BPF_REG_8, BPF_PSEUDO_MAP_IDX_VALUE, 0, 0, 0, insn)); + switch (relo->kind) { + case BTF_KIND_VAR: + if (relo->is_typeless) + emit_relo_ksym_typeless(gen, relo, insn); + else + emit_relo_ksym_btf(gen, relo, insn); + break; + case BTF_KIND_FUNC: + emit_relo_kfunc_btf(gen, relo, insn); + break; + default: + pr_warn("Unknown relocation kind '%d'\n", relo->kind); + gen->error = -EDOM; + return; } } @@ -571,14 +874,23 @@ static void cleanup_relos(struct bpf_gen *gen, int insns) { int i, insn; - for (i = 0; i < gen->relo_cnt; i++) { - if (gen->relos[i].kind != BTF_KIND_VAR) - continue; - /* close fd recorded in insn[insn_idx + 1].imm */ - insn = insns + - sizeof(struct bpf_insn) * (gen->relos[i].insn_idx + 1) + - offsetof(struct bpf_insn, imm); - emit_sys_close_blob(gen, insn); + for (i = 0; i < gen->nr_ksyms; i++) { + /* only close fds for typed ksyms and kfuncs */ + if (gen->ksyms[i].kind == BTF_KIND_VAR && !gen->ksyms[i].typeless) { + /* close fd recorded in insn[insn_idx + 1].imm */ + insn = gen->ksyms[i].insn; + insn += sizeof(struct bpf_insn) + offsetof(struct bpf_insn, imm); + emit_sys_close_blob(gen, insn); + } else if (gen->ksyms[i].kind == BTF_KIND_FUNC) { + emit_sys_close_blob(gen, blob_fd_array_off(gen, gen->ksyms[i].off)); + if (gen->ksyms[i].off < MAX_FD_ARRAY_SZ) + gen->nr_fd_array--; + } + } + if (gen->nr_ksyms) { + free(gen->ksyms); + gen->nr_ksyms = 0; + gen->ksyms = NULL; } if (gen->relo_cnt) { free(gen->relos); @@ -637,9 +949,8 @@ void bpf_gen__prog_load(struct bpf_gen *gen, /* populate union bpf_attr with a pointer to line_info */ emit_rel_store(gen, attr_field(prog_load_attr, line_info), line_info); - /* populate union bpf_attr fd_array with a pointer to stack where map_fds are saved */ - emit_rel_store_sp(gen, attr_field(prog_load_attr, fd_array), - stack_off(map_fd[0])); + /* populate union bpf_attr fd_array with a pointer to data where map_fds are saved */ + emit_rel_store(gen, attr_field(prog_load_attr, fd_array), gen->fd_array); /* populate union bpf_attr with user provided log details */ move_ctx2blob(gen, attr_field(prog_load_attr, log_level), 4, @@ -706,8 +1017,8 @@ void bpf_gen__map_update_elem(struct bpf_gen *gen, int map_idx, void *pvalue, emit(gen, BPF_EMIT_CALL(BPF_FUNC_copy_from_user)); map_update_attr = add_data(gen, &attr, attr_size); - move_stack2blob(gen, attr_field(map_update_attr, map_fd), 4, - stack_off(map_fd[map_idx])); + move_blob2blob(gen, attr_field(map_update_attr, map_fd), 4, + blob_fd_array_off(gen, map_idx)); emit_rel_store(gen, attr_field(map_update_attr, key), key); emit_rel_store(gen, attr_field(map_update_attr, value), value); /* emit MAP_UPDATE_ELEM command */ @@ -725,8 +1036,8 @@ void bpf_gen__map_freeze(struct bpf_gen *gen, int map_idx) memset(&attr, 0, attr_size); pr_debug("gen: map_freeze: idx %d\n", map_idx); map_freeze_attr = add_data(gen, &attr, attr_size); - move_stack2blob(gen, attr_field(map_freeze_attr, map_fd), 4, - stack_off(map_fd[map_idx])); + move_blob2blob(gen, attr_field(map_freeze_attr, map_fd), 4, + blob_fd_array_off(gen, map_idx)); /* emit MAP_FREEZE command */ emit_sys_bpf(gen, BPF_MAP_FREEZE, map_freeze_attr, attr_size); debug_ret(gen, "map_freeze"); |
