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

Daniel Borkmann says:

====================
pull-request: bpf 2019-12-02

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

We've added 10 non-merge commits during the last 6 day(s) which contain
a total of 10 files changed, 60 insertions(+), 51 deletions(-).

The main changes are:

1) Fix vmlinux BTF generation for binutils pre v2.25, from Stanislav Fomichev.

2) Fix libbpf global variable relocation to take symbol's st_value offset
   into account, from Andrii Nakryiko.

3) Fix libbpf build on powerpc where check_abi target fails due to different
   readelf output format, from Aurelien Jarno.

4) Don't set BPF insns RO for the case when they are JITed in order to avoid
   fragmenting the direct map, from Daniel Borkmann.

5) Fix static checker warning in btf_distill_func_proto() as well as a build
   error due to empty enum when BPF is compiled out, from Alexei Starovoitov.

6) Fix up generation of bpf_helper_defs.h for perf, from Arnaldo Carvalho de Melo.
====================

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

2 files changed, 25 insertions, 30 deletions

diff --git a/tools/lib/bpf/Makefile b/tools/lib/bpf/Makefile
index 99425d0be6ff..3d3d024f7b94 100644
--- a/tools/lib/bpf/Makefile
+++ b/tools/lib/bpf/Makefile
@@ -147,7 +147,7 @@ TAGS_PROG := $(if $(shell which etags 2>/dev/null),etags,ctags)
 
 GLOBAL_SYM_COUNT = $(shell readelf -s --wide $(BPF_IN_SHARED) | \
 			   cut -d "@" -f1 | sed 's/_v[0-9]_[0-9]_[0-9].*//' | \
-			   awk '/GLOBAL/ && /DEFAULT/ && !/UND/ {print $$8}' | \
+			   awk '/GLOBAL/ && /DEFAULT/ && !/UND/ {print $$NF}' | \
 			   sort -u | wc -l)
 VERSIONED_SYM_COUNT = $(shell readelf -s --wide $(OUTPUT)libbpf.so | \
 			      grep -Eo '[^ ]+@LIBBPF_' | cut -d@ -f1 | sort -u | wc -l)
@@ -180,9 +180,9 @@ $(BPF_IN_SHARED): force elfdep bpfdep bpf_helper_defs.h
 $(BPF_IN_STATIC): force elfdep bpfdep bpf_helper_defs.h
 	$(Q)$(MAKE) $(build)=libbpf OUTPUT=$(STATIC_OBJDIR)
 
-bpf_helper_defs.h: $(srctree)/include/uapi/linux/bpf.h
+bpf_helper_defs.h: $(srctree)/tools/include/uapi/linux/bpf.h
 	$(Q)$(srctree)/scripts/bpf_helpers_doc.py --header 		\
-		--file $(srctree)/include/uapi/linux/bpf.h > bpf_helper_defs.h
+		--file $(srctree)/tools/include/uapi/linux/bpf.h > bpf_helper_defs.h
 
 $(OUTPUT)libbpf.so: $(OUTPUT)libbpf.so.$(LIBBPF_VERSION)
 
@@ -214,9 +214,9 @@ check_abi: $(OUTPUT)libbpf.so
 		     "versioned symbols in $^ ($(VERSIONED_SYM_COUNT))." \
 		     "Please make sure all LIBBPF_API symbols are"	 \
 		     "versioned in $(VERSION_SCRIPT)." >&2;		 \
-		readelf -s --wide $(OUTPUT)libbpf-in.o |		 \
+		readelf -s --wide $(BPF_IN_SHARED) |			 \
 		    cut -d "@" -f1 | sed 's/_v[0-9]_[0-9]_[0-9].*//' |	 \
-		    awk '/GLOBAL/ && /DEFAULT/ && !/UND/ {print $$8}'|   \
+		    awk '/GLOBAL/ && /DEFAULT/ && !/UND/ {print $$NF}'|  \
 		    sort -u > $(OUTPUT)libbpf_global_syms.tmp;		 \
 		readelf -s --wide $(OUTPUT)libbpf.so |			 \
 		    grep -Eo '[^ ]+@LIBBPF_' | cut -d@ -f1 |		 \
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index b20f82e58989..3f09772192f1 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -171,10 +171,8 @@ struct bpf_program {
 			RELO_DATA,
 		} type;
 		int insn_idx;
-		union {
-			int map_idx;
-			int text_off;
-		};
+		int map_idx;
+		int sym_off;
 	} *reloc_desc;
 	int nr_reloc;
 	int log_level;
@@ -1819,12 +1817,12 @@ static int bpf_program__record_reloc(struct bpf_program *prog,
 			return -LIBBPF_ERRNO__RELOC;
 		}
 		if (sym->st_value % 8) {
-			pr_warn("bad call relo offset: %lu\n", sym->st_value);
+			pr_warn("bad call relo offset: %llu\n", (__u64)sym->st_value);
 			return -LIBBPF_ERRNO__RELOC;
 		}
 		reloc_desc->type = RELO_CALL;
 		reloc_desc->insn_idx = insn_idx;
-		reloc_desc->text_off = sym->st_value / 8;
+		reloc_desc->sym_off = sym->st_value;
 		obj->has_pseudo_calls = true;
 		return 0;
 	}
@@ -1868,6 +1866,7 @@ static int bpf_program__record_reloc(struct bpf_program *prog,
 		reloc_desc->type = RELO_LD64;
 		reloc_desc->insn_idx = insn_idx;
 		reloc_desc->map_idx = map_idx;
+		reloc_desc->sym_off = 0; /* sym->st_value determines map_idx */
 		return 0;
 	}
 
@@ -1899,6 +1898,7 @@ static int bpf_program__record_reloc(struct bpf_program *prog,
 	reloc_desc->type = RELO_DATA;
 	reloc_desc->insn_idx = insn_idx;
 	reloc_desc->map_idx = map_idx;
+	reloc_desc->sym_off = sym->st_value;
 	return 0;
 }
 
@@ -3563,8 +3563,8 @@ bpf_program__reloc_text(struct bpf_program *prog, struct bpf_object *obj,
 		return -LIBBPF_ERRNO__RELOC;
 
 	if (prog->idx == obj->efile.text_shndx) {
-		pr_warn("relo in .text insn %d into off %d\n",
-			relo->insn_idx, relo->text_off);
+		pr_warn("relo in .text insn %d into off %d (insn #%d)\n",
+			relo->insn_idx, relo->sym_off, relo->sym_off / 8);
 		return -LIBBPF_ERRNO__RELOC;
 	}
 
@@ -3599,7 +3599,7 @@ bpf_program__reloc_text(struct bpf_program *prog, struct bpf_object *obj,
 			 prog->section_name);
 	}
 	insn = &prog->insns[relo->insn_idx];
-	insn->imm += relo->text_off + prog->main_prog_cnt - relo->insn_idx;
+	insn->imm += relo->sym_off / 8 + prog->main_prog_cnt - relo->insn_idx;
 	return 0;
 }
 
@@ -3622,31 +3622,26 @@ bpf_program__relocate(struct bpf_program *prog, struct bpf_object *obj)
 		return 0;
 
 	for (i = 0; i < prog->nr_reloc; i++) {
-		if (prog->reloc_desc[i].type == RELO_LD64 ||
-		    prog->reloc_desc[i].type == RELO_DATA) {
-			bool relo_data = prog->reloc_desc[i].type == RELO_DATA;
-			struct bpf_insn *insns = prog->insns;
-			int insn_idx, map_idx;
+		struct reloc_desc *relo = &prog->reloc_desc[i];
 
-			insn_idx = prog->reloc_desc[i].insn_idx;
-			map_idx = prog->reloc_desc[i].map_idx;
+		if (relo->type == RELO_LD64 || relo->type == RELO_DATA) {
+			struct bpf_insn *insn = &prog->insns[relo->insn_idx];
 
-			if (insn_idx + 1 >= (int)prog->insns_cnt) {
+			if (relo->insn_idx + 1 >= (int)prog->insns_cnt) {
 				pr_warn("relocation out of range: '%s'\n",
 					prog->section_name);
 				return -LIBBPF_ERRNO__RELOC;
 			}
 
-			if (!relo_data) {
-				insns[insn_idx].src_reg = BPF_PSEUDO_MAP_FD;
+			if (relo->type != RELO_DATA) {
+				insn[0].src_reg = BPF_PSEUDO_MAP_FD;
 			} else {
-				insns[insn_idx].src_reg = BPF_PSEUDO_MAP_VALUE;
-				insns[insn_idx + 1].imm = insns[insn_idx].imm;
+				insn[0].src_reg = BPF_PSEUDO_MAP_VALUE;
+				insn[1].imm = insn[0].imm + relo->sym_off;
 			}
-			insns[insn_idx].imm = obj->maps[map_idx].fd;
-		} else if (prog->reloc_desc[i].type == RELO_CALL) {
-			err = bpf_program__reloc_text(prog, obj,
-						      &prog->reloc_desc[i]);
+			insn[0].imm = obj->maps[relo->map_idx].fd;
+		} else if (relo->type == RELO_CALL) {
+			err = bpf_program__reloc_text(prog, obj, relo);
 			if (err)
 				return err;
 		}