diff --git a/include/linux/filter.h b/include/linux/filter.h
index e872b4ebaa575..2b0df27036711 100644
--- a/include/linux/filter.h
+++ b/include/linux/filter.h
@@ -18,6 +18,7 @@
#include <linux/capability.h>
#include <linux/cryptohash.h>
#include <linux/set_memory.h>
+#include <linux/kallsyms.h>
#include <net/sch_generic.h>
@@ -724,6 +725,14 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog);
void bpf_jit_compile(struct bpf_prog *prog);
bool bpf_helper_changes_pkt_data(void *func);
+static inline bool bpf_dump_raw_ok(void)
+{
+ /* Reconstruction of call-sites is dependent on kallsyms,
+ * thus make dump the same restriction.
+ */
+ return kallsyms_show_value() == 1;
+}
+
struct bpf_prog *bpf_patch_insn_single(struct bpf_prog *prog, u32 off,
const struct bpf_insn *patch, u32 len);
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
index 768e0a02d8c8a..70a534549cd3e 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 883f88fa5bfc6..8740406df2cd7 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 8de977e420b64..e0857d016f895 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 30e728dcd35d6..007802c5ca7d7 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 3c3eec58b3e81..4ae46b2cba880 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;
diff --git a/tools/bpf/bpftool/prog.c b/tools/bpf/bpftool/prog.c
index 037484ceaeaf7..42ee8892549cc 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: