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-rw-r--r--kernel/bpf/core.c4
-rw-r--r--kernel/bpf/disasm.c65
-rw-r--r--kernel/bpf/disasm.h29
-rw-r--r--kernel/bpf/syscall.c87
-rw-r--r--kernel/bpf/verifier.c30
5 files changed, 189 insertions, 26 deletions
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
index 768e0a02d8c8..70a534549cd3 100644
--- a/kernel/bpf/core.c
+++ b/kernel/bpf/core.c
@@ -771,7 +771,9 @@ struct bpf_prog *bpf_jit_blind_constants(struct bpf_prog *prog)
/* Base function for offset calculation. Needs to go into .text section,
* therefore keeping it non-static as well; will also be used by JITs
- * anyway later on, so do not let the compiler omit it.
+ * anyway later on, so do not let the compiler omit it. This also needs
+ * to go into kallsyms for correlation from e.g. bpftool, so naming
+ * must not change.
*/
noinline u64 __bpf_call_base(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5)
{
diff --git a/kernel/bpf/disasm.c b/kernel/bpf/disasm.c
index 883f88fa5bfc..8740406df2cd 100644
--- a/kernel/bpf/disasm.c
+++ b/kernel/bpf/disasm.c
@@ -21,10 +21,39 @@ static const char * const func_id_str[] = {
};
#undef __BPF_FUNC_STR_FN
-const char *func_id_name(int id)
+static const char *__func_get_name(const struct bpf_insn_cbs *cbs,
+ const struct bpf_insn *insn,
+ char *buff, size_t len)
{
BUILD_BUG_ON(ARRAY_SIZE(func_id_str) != __BPF_FUNC_MAX_ID);
+ if (insn->src_reg != BPF_PSEUDO_CALL &&
+ insn->imm >= 0 && insn->imm < __BPF_FUNC_MAX_ID &&
+ func_id_str[insn->imm])
+ return func_id_str[insn->imm];
+
+ if (cbs && cbs->cb_call)
+ return cbs->cb_call(cbs->private_data, insn);
+
+ if (insn->src_reg == BPF_PSEUDO_CALL)
+ snprintf(buff, len, "%+d", insn->imm);
+
+ return buff;
+}
+
+static const char *__func_imm_name(const struct bpf_insn_cbs *cbs,
+ const struct bpf_insn *insn,
+ u64 full_imm, char *buff, size_t len)
+{
+ if (cbs && cbs->cb_imm)
+ return cbs->cb_imm(cbs->private_data, insn, full_imm);
+
+ snprintf(buff, len, "0x%llx", (unsigned long long)full_imm);
+ return buff;
+}
+
+const char *func_id_name(int id)
+{
if (id >= 0 && id < __BPF_FUNC_MAX_ID && func_id_str[id])
return func_id_str[id];
else
@@ -83,7 +112,7 @@ static const char *const bpf_jmp_string[16] = {
[BPF_EXIT >> 4] = "exit",
};
-static void print_bpf_end_insn(bpf_insn_print_cb verbose,
+static void print_bpf_end_insn(bpf_insn_print_t verbose,
struct bpf_verifier_env *env,
const struct bpf_insn *insn)
{
@@ -92,9 +121,12 @@ static void print_bpf_end_insn(bpf_insn_print_cb verbose,
insn->imm, insn->dst_reg);
}
-void print_bpf_insn(bpf_insn_print_cb verbose, struct bpf_verifier_env *env,
- const struct bpf_insn *insn, bool allow_ptr_leaks)
+void print_bpf_insn(const struct bpf_insn_cbs *cbs,
+ struct bpf_verifier_env *env,
+ const struct bpf_insn *insn,
+ bool allow_ptr_leaks)
{
+ const bpf_insn_print_t verbose = cbs->cb_print;
u8 class = BPF_CLASS(insn->code);
if (class == BPF_ALU || class == BPF_ALU64) {
@@ -175,12 +207,15 @@ void print_bpf_insn(bpf_insn_print_cb verbose, struct bpf_verifier_env *env,
*/
u64 imm = ((u64)(insn + 1)->imm << 32) | (u32)insn->imm;
bool map_ptr = insn->src_reg == BPF_PSEUDO_MAP_FD;
+ char tmp[64];
if (map_ptr && !allow_ptr_leaks)
imm = 0;
- verbose(env, "(%02x) r%d = 0x%llx\n", insn->code,
- insn->dst_reg, (unsigned long long)imm);
+ verbose(env, "(%02x) r%d = %s\n",
+ insn->code, insn->dst_reg,
+ __func_imm_name(cbs, insn, imm,
+ tmp, sizeof(tmp)));
} else {
verbose(env, "BUG_ld_%02x\n", insn->code);
return;
@@ -189,12 +224,20 @@ void print_bpf_insn(bpf_insn_print_cb verbose, struct bpf_verifier_env *env,
u8 opcode = BPF_OP(insn->code);
if (opcode == BPF_CALL) {
- if (insn->src_reg == BPF_PSEUDO_CALL)
- verbose(env, "(%02x) call pc%+d\n", insn->code,
- insn->imm);
- else
+ char tmp[64];
+
+ if (insn->src_reg == BPF_PSEUDO_CALL) {
+ verbose(env, "(%02x) call pc%s\n",
+ insn->code,
+ __func_get_name(cbs, insn,
+ tmp, sizeof(tmp)));
+ } else {
+ strcpy(tmp, "unknown");
verbose(env, "(%02x) call %s#%d\n", insn->code,
- func_id_name(insn->imm), insn->imm);
+ __func_get_name(cbs, insn,
+ tmp, sizeof(tmp)),
+ insn->imm);
+ }
} else if (insn->code == (BPF_JMP | BPF_JA)) {
verbose(env, "(%02x) goto pc%+d\n",
insn->code, insn->off);
diff --git a/kernel/bpf/disasm.h b/kernel/bpf/disasm.h
index 8de977e420b6..e0857d016f89 100644
--- a/kernel/bpf/disasm.h
+++ b/kernel/bpf/disasm.h
@@ -17,16 +17,35 @@
#include <linux/bpf.h>
#include <linux/kernel.h>
#include <linux/stringify.h>
+#ifndef __KERNEL__
+#include <stdio.h>
+#include <string.h>
+#endif
+
+struct bpf_verifier_env;
extern const char *const bpf_alu_string[16];
extern const char *const bpf_class_string[8];
const char *func_id_name(int id);
-struct bpf_verifier_env;
-typedef void (*bpf_insn_print_cb)(struct bpf_verifier_env *env,
- const char *, ...);
-void print_bpf_insn(bpf_insn_print_cb verbose, struct bpf_verifier_env *env,
- const struct bpf_insn *insn, bool allow_ptr_leaks);
+typedef void (*bpf_insn_print_t)(struct bpf_verifier_env *env,
+ const char *, ...);
+typedef const char *(*bpf_insn_revmap_call_t)(void *private_data,
+ const struct bpf_insn *insn);
+typedef const char *(*bpf_insn_print_imm_t)(void *private_data,
+ const struct bpf_insn *insn,
+ __u64 full_imm);
+
+struct bpf_insn_cbs {
+ bpf_insn_print_t cb_print;
+ bpf_insn_revmap_call_t cb_call;
+ bpf_insn_print_imm_t cb_imm;
+ void *private_data;
+};
+void print_bpf_insn(const struct bpf_insn_cbs *cbs,
+ struct bpf_verifier_env *env,
+ const struct bpf_insn *insn,
+ bool allow_ptr_leaks);
#endif
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 30e728dcd35d..007802c5ca7d 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -1558,6 +1558,67 @@ static int bpf_map_get_fd_by_id(const union bpf_attr *attr)
return fd;
}
+static const struct bpf_map *bpf_map_from_imm(const struct bpf_prog *prog,
+ unsigned long addr)
+{
+ int i;
+
+ for (i = 0; i < prog->aux->used_map_cnt; i++)
+ if (prog->aux->used_maps[i] == (void *)addr)
+ return prog->aux->used_maps[i];
+ return NULL;
+}
+
+static struct bpf_insn *bpf_insn_prepare_dump(const struct bpf_prog *prog)
+{
+ const struct bpf_map *map;
+ struct bpf_insn *insns;
+ u64 imm;
+ int i;
+
+ insns = kmemdup(prog->insnsi, bpf_prog_insn_size(prog),
+ GFP_USER);
+ if (!insns)
+ return insns;
+
+ for (i = 0; i < prog->len; i++) {
+ if (insns[i].code == (BPF_JMP | BPF_TAIL_CALL)) {
+ insns[i].code = BPF_JMP | BPF_CALL;
+ insns[i].imm = BPF_FUNC_tail_call;
+ /* fall-through */
+ }
+ if (insns[i].code == (BPF_JMP | BPF_CALL) ||
+ insns[i].code == (BPF_JMP | BPF_CALL_ARGS)) {
+ if (insns[i].code == (BPF_JMP | BPF_CALL_ARGS))
+ insns[i].code = BPF_JMP | BPF_CALL;
+ if (!bpf_dump_raw_ok())
+ insns[i].imm = 0;
+ continue;
+ }
+
+ if (insns[i].code != (BPF_LD | BPF_IMM | BPF_DW))
+ continue;
+
+ imm = ((u64)insns[i + 1].imm << 32) | (u32)insns[i].imm;
+ map = bpf_map_from_imm(prog, imm);
+ if (map) {
+ insns[i].src_reg = BPF_PSEUDO_MAP_FD;
+ insns[i].imm = map->id;
+ insns[i + 1].imm = 0;
+ continue;
+ }
+
+ if (!bpf_dump_raw_ok() &&
+ imm == (unsigned long)prog->aux) {
+ insns[i].imm = 0;
+ insns[i + 1].imm = 0;
+ continue;
+ }
+ }
+
+ return insns;
+}
+
static int bpf_prog_get_info_by_fd(struct bpf_prog *prog,
const union bpf_attr *attr,
union bpf_attr __user *uattr)
@@ -1608,18 +1669,34 @@ static int bpf_prog_get_info_by_fd(struct bpf_prog *prog,
ulen = info.jited_prog_len;
info.jited_prog_len = prog->jited_len;
if (info.jited_prog_len && ulen) {
- uinsns = u64_to_user_ptr(info.jited_prog_insns);
- ulen = min_t(u32, info.jited_prog_len, ulen);
- if (copy_to_user(uinsns, prog->bpf_func, ulen))
- return -EFAULT;
+ if (bpf_dump_raw_ok()) {
+ uinsns = u64_to_user_ptr(info.jited_prog_insns);
+ ulen = min_t(u32, info.jited_prog_len, ulen);
+ if (copy_to_user(uinsns, prog->bpf_func, ulen))
+ return -EFAULT;
+ } else {
+ info.jited_prog_insns = 0;
+ }
}
ulen = info.xlated_prog_len;
info.xlated_prog_len = bpf_prog_insn_size(prog);
if (info.xlated_prog_len && ulen) {
+ struct bpf_insn *insns_sanitized;
+ bool fault;
+
+ if (prog->blinded && !bpf_dump_raw_ok()) {
+ info.xlated_prog_insns = 0;
+ goto done;
+ }
+ insns_sanitized = bpf_insn_prepare_dump(prog);
+ if (!insns_sanitized)
+ return -ENOMEM;
uinsns = u64_to_user_ptr(info.xlated_prog_insns);
ulen = min_t(u32, info.xlated_prog_len, ulen);
- if (copy_to_user(uinsns, prog->insnsi, ulen))
+ fault = copy_to_user(uinsns, insns_sanitized, ulen);
+ kfree(insns_sanitized);
+ if (fault)
return -EFAULT;
}
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 3c3eec58b3e8..4ae46b2cba88 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -4427,9 +4427,12 @@ static int do_check(struct bpf_verifier_env *env)
}
if (env->log.level) {
+ const struct bpf_insn_cbs cbs = {
+ .cb_print = verbose,
+ };
+
verbose(env, "%d: ", insn_idx);
- print_bpf_insn(verbose, env, insn,
- env->allow_ptr_leaks);
+ print_bpf_insn(&cbs, env, insn, env->allow_ptr_leaks);
}
err = ext_analyzer_insn_hook(env, insn_idx, prev_insn_idx);
@@ -5017,14 +5020,14 @@ static int jit_subprogs(struct bpf_verifier_env *env)
{
struct bpf_prog *prog = env->prog, **func, *tmp;
int i, j, subprog_start, subprog_end = 0, len, subprog;
- struct bpf_insn *insn = prog->insnsi;
+ struct bpf_insn *insn;
void *old_bpf_func;
int err = -ENOMEM;
if (env->subprog_cnt == 0)
return 0;
- for (i = 0; i < prog->len; i++, insn++) {
+ for (i = 0, insn = prog->insnsi; i < prog->len; i++, insn++) {
if (insn->code != (BPF_JMP | BPF_CALL) ||
insn->src_reg != BPF_PSEUDO_CALL)
continue;
@@ -5116,6 +5119,25 @@ static int jit_subprogs(struct bpf_verifier_env *env)
bpf_prog_lock_ro(func[i]);
bpf_prog_kallsyms_add(func[i]);
}
+
+ /* Last step: make now unused interpreter insns from main
+ * prog consistent for later dump requests, so they can
+ * later look the same as if they were interpreted only.
+ */
+ for (i = 0, insn = prog->insnsi; i < prog->len; i++, insn++) {
+ unsigned long addr;
+
+ if (insn->code != (BPF_JMP | BPF_CALL) ||
+ insn->src_reg != BPF_PSEUDO_CALL)
+ continue;
+ insn->off = env->insn_aux_data[i].call_imm;
+ subprog = find_subprog(env, i + insn->off + 1);
+ addr = (unsigned long)func[subprog + 1]->bpf_func;
+ addr &= PAGE_MASK;
+ insn->imm = (u64 (*)(u64, u64, u64, u64, u64))
+ addr - __bpf_call_base;
+ }
+
prog->jited = 1;
prog->bpf_func = func[0]->bpf_func;
prog->aux->func = func;
generated by cgit v1.2.3 (git 2.25.1) at 2024-09-09 13:57:40 +0000