Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

Daniel Borkmann says:

====================
pull-request: bpf-next 2017-12-28

The following pull-request contains BPF updates for your *net-next* tree.

The main changes are:

1) Fix incorrect state pruning related to recognition of zero initialized
   stack slots, where stacksafe exploration would mistakenly return a
   positive pruning verdict too early ignoring other slots, from Gianluca.

2) Various BPF to BPF calls related follow-up fixes. Fix an off-by-one
   in maximum call depth check, and rework maximum stack depth tracking
   logic to fix a bypass of the total stack size check reported by Jann.
   Also fix a bug in arm64 JIT where prog->jited_len was uninitialized.
   Addition of various test cases to BPF selftests, from Alexei.

3) Addition of a BPF selftest to test_verifier that is related to BPF to
   BPF calls which demonstrates a late caller stack size increase and
   thus out of bounds access. Fixed above in 2). Test case from Jann.

4) Addition of correlating BPF helper calls, BPF to BPF calls as well
   as BPF maps to bpftool xlated dump in order to allow for better
   BPF program introspection and debugging, from Daniel.

5) Fixing several bugs in BPF to BPF calls kallsyms handling in order
   to get it actually to work for subprogs, from Daniel.

6) Extending sparc64 JIT support for BPF to BPF calls and fix a couple
   of build errors for libbpf on sparc64, from David.

7) Allow narrower context access for BPF dev cgroup typed programs in
   order to adapt to LLVM code generation. Also adjust memlock rlimit
   in the test_dev_cgroup BPF selftest, from Yonghong.

8) Add netdevsim Kconfig entry to BPF selftests since test_offload.py
   relies on netdevsim device being available, from Jakub.

9) Reduce scope of xdp_do_generic_redirect_map() to being static,
   from Xiongwei.

10) Minor cleanups and spelling fixes in BPF verifier, from Colin.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

arch/arm64/net/bpf_jit_comp.c

@@ -897,6 +897,7 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
 		image_ptr = jit_data->image;
 		header = jit_data->header;
 		extra_pass = true;
+		image_size = sizeof(u32) * ctx.idx;
 		goto skip_init_ctx;
 	}
 	memset(&ctx, 0, sizeof(ctx));

arch/sparc/net/bpf_jit_comp_64.c

@@ -1509,11 +1509,19 @@ static void jit_fill_hole(void *area, unsigned int size)
 		*ptr++ = 0x91d02005; /* ta 5 */
 }
 
+struct sparc64_jit_data {
+	struct bpf_binary_header *header;
+	u8 *image;
+	struct jit_ctx ctx;
+};
+
 struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
 {
 	struct bpf_prog *tmp, *orig_prog = prog;
+	struct sparc64_jit_data *jit_data;
 	struct bpf_binary_header *header;
 	bool tmp_blinded = false;
+	bool extra_pass = false;
 	struct jit_ctx ctx;
 	u32 image_size;
 	u8 *image_ptr;
@@ -1533,13 +1541,31 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
 		prog = tmp;
 	}
 
+	jit_data = prog->aux->jit_data;
+	if (!jit_data) {
+		jit_data = kzalloc(sizeof(*jit_data), GFP_KERNEL);
+		if (!jit_data) {
+			prog = orig_prog;
+			goto out;
+		}
+		prog->aux->jit_data = jit_data;
+	}
+	if (jit_data->ctx.offset) {
+		ctx = jit_data->ctx;
+		image_ptr = jit_data->image;
+		header = jit_data->header;
+		extra_pass = true;
+		image_size = sizeof(u32) * ctx.idx;
+		goto skip_init_ctx;
+	}
+
 	memset(&ctx, 0, sizeof(ctx));
 	ctx.prog = prog;
 
 	ctx.offset = kcalloc(prog->len, sizeof(unsigned int), GFP_KERNEL);
 	if (ctx.offset == NULL) {
 		prog = orig_prog;
-		goto out;
+		goto out_off;
 	}
 
 	/* Fake pass to detect features used, and get an accurate assessment
@@ -1562,7 +1588,7 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
 	}
 
 	ctx.image = (u32 *)image_ptr;
-
+skip_init_ctx:
 	for (pass = 1; pass < 3; pass++) {
 		ctx.idx = 0;
 
@@ -1593,14 +1619,24 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
 
 	bpf_flush_icache(header, (u8 *)header + (header->pages * PAGE_SIZE));
 
-	bpf_jit_binary_lock_ro(header);
+	if (!prog->is_func || extra_pass) {
+		bpf_jit_binary_lock_ro(header);
+	} else {
+		jit_data->ctx = ctx;
+		jit_data->image = image_ptr;
+		jit_data->header = header;
+	}
 
 	prog->bpf_func = (void *)ctx.image;
 	prog->jited = 1;
 	prog->jited_len = image_size;
 
+	if (!prog->is_func || extra_pass) {
 out_off:
-	kfree(ctx.offset);
+		kfree(ctx.offset);
+		kfree(jit_data);
+		prog->aux->jit_data = NULL;
+	}
 out:
 	if (tmp_blinded)
 		bpf_jit_prog_release_other(prog, prog == orig_prog ?

include/linux/bpf_verifier.h

@@ -194,6 +194,7 @@ struct bpf_verifier_env {
 	struct bpf_insn_aux_data *insn_aux_data; /* array of per-insn state */
 	struct bpf_verifer_log log;
 	u32 subprog_starts[BPF_MAX_SUBPROGS];
+	/* computes the stack depth of each bpf function */
 	u16 subprog_stack_depth[BPF_MAX_SUBPROGS + 1];
 	u32 subprog_cnt;
 };

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);
 

include/uapi/linux/bpf.h

@@ -1012,7 +1012,8 @@ struct bpf_perf_event_value {
 #define BPF_DEVCG_DEV_CHAR	(1ULL << 1)
 
 struct bpf_cgroup_dev_ctx {
-	__u32 access_type; /* (access << 16) | type */
+	/* access_type encoded as (BPF_DEVCG_ACC_* << 16) | BPF_DEVCG_DEV_* */
+	__u32 access_type;
 	__u32 major;
 	__u32 minor;
 };

kernel/bpf/cgroup.c

@@ -568,6 +568,8 @@ static bool cgroup_dev_is_valid_access(int off, int size,
 				       enum bpf_access_type type,
 				       struct bpf_insn_access_aux *info)
 {
+	const int size_default = sizeof(__u32);
+
 	if (type == BPF_WRITE)
 		return false;
 
@@ -576,8 +578,17 @@ static bool cgroup_dev_is_valid_access(int off, int size,
 	/* The verifier guarantees that size > 0. */
 	if (off % size != 0)
 		return false;
-	if (size != sizeof(__u32))
-		return false;
+
+	switch (off) {
+	case bpf_ctx_range(struct bpf_cgroup_dev_ctx, access_type):
+		bpf_ctx_record_field_size(info, size_default);
+		if (!bpf_ctx_narrow_access_ok(off, size, size_default))
+			return false;
+		break;
+	default:
+		if (size != size_default)
+			return false;
+	}
 
 	return true;
 }

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)
 {

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);

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