libbpf: Fix global variable relocation

Similarly to a0d7da26ce86 ("libbpf: Fix call relocation offset calculation
bug"), relocations against global variables need to take into account
referenced symbol's st_value, which holds offset into a corresponding data
section (and, subsequently, offset into internal backing map). For static
variables this offset is always zero and data offset is completely described
by respective instruction's imm field.

Convert a bunch of selftests to global variables. Previously they were relying
on `static volatile` trick to ensure Clang doesn't inline static variables,
which with global variables is not necessary anymore.

Fixes: 393cdfbee809 ("libbpf: Support initialized global variables")
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20191127200651.1381348-1-andriin@fb.com

4 files changed, 17 insertions, 17 deletions

diff --git a/tools/testing/selftests/bpf/progs/fentry_test.c b/tools/testing/selftests/bpf/progs/fentry_test.c
index d2af9f039df5..615f7c6bca77 100644
--- a/tools/testing/selftests/bpf/progs/fentry_test.c
+++ b/tools/testing/selftests/bpf/progs/fentry_test.c
@@ -6,28 +6,28 @@
 
 char _license[] SEC("license") = "GPL";
 
-static volatile __u64 test1_result;
+__u64 test1_result = 0;
 BPF_TRACE_1("fentry/bpf_fentry_test1", test1, int, a)
 {
 	test1_result = a == 1;
 	return 0;
 }
 
-static volatile __u64 test2_result;
+__u64 test2_result = 0;
 BPF_TRACE_2("fentry/bpf_fentry_test2", test2, int, a, __u64, b)
 {
 	test2_result = a == 2 && b == 3;
 	return 0;
 }
 
-static volatile __u64 test3_result;
+__u64 test3_result = 0;
 BPF_TRACE_3("fentry/bpf_fentry_test3", test3, char, a, int, b, __u64, c)
 {
 	test3_result = a == 4 && b == 5 && c == 6;
 	return 0;
 }
 
-static volatile __u64 test4_result;
+__u64 test4_result = 0;
 BPF_TRACE_4("fentry/bpf_fentry_test4", test4,
 	    void *, a, char, b, int, c, __u64, d)
 {
@@ -35,7 +35,7 @@ BPF_TRACE_4("fentry/bpf_fentry_test4", test4,
 	return 0;
 }
 
-static volatile __u64 test5_result;
+__u64 test5_result = 0;
 BPF_TRACE_5("fentry/bpf_fentry_test5", test5,
 	    __u64, a, void *, b, short, c, int, d, __u64, e)
 {
@@ -44,7 +44,7 @@ BPF_TRACE_5("fentry/bpf_fentry_test5", test5,
 	return 0;
 }
 
-static volatile __u64 test6_result;
+__u64 test6_result = 0;
 BPF_TRACE_6("fentry/bpf_fentry_test6", test6,
 	    __u64, a, void *, b, short, c, int, d, void *, e, __u64, f)
 {
diff --git a/tools/testing/selftests/bpf/progs/fexit_bpf2bpf.c b/tools/testing/selftests/bpf/progs/fexit_bpf2bpf.c
index 525d47d7b589..2d211ee98a1c 100644
--- a/tools/testing/selftests/bpf/progs/fexit_bpf2bpf.c
+++ b/tools/testing/selftests/bpf/progs/fexit_bpf2bpf.c
@@ -8,7 +8,7 @@ struct sk_buff {
 	unsigned int len;
 };
 
-static volatile __u64 test_result;
+__u64 test_result = 0;
 BPF_TRACE_2("fexit/test_pkt_access", test_main,
 	    struct sk_buff *, skb, int, ret)
 {
@@ -23,7 +23,7 @@ BPF_TRACE_2("fexit/test_pkt_access", test_main,
 	return 0;
 }
 
-static volatile __u64 test_result_subprog1;
+__u64 test_result_subprog1 = 0;
 BPF_TRACE_2("fexit/test_pkt_access_subprog1", test_subprog1,
 	    struct sk_buff *, skb, int, ret)
 {
@@ -56,7 +56,7 @@ struct args_subprog2 {
 	__u64 args[5];
 	__u64 ret;
 };
-static volatile __u64 test_result_subprog2;
+__u64 test_result_subprog2 = 0;
 SEC("fexit/test_pkt_access_subprog2")
 int test_subprog2(struct args_subprog2 *ctx)
 {
diff --git a/tools/testing/selftests/bpf/progs/fexit_test.c b/tools/testing/selftests/bpf/progs/fexit_test.c
index 2487e98edb34..86db0d60fb6e 100644
--- a/tools/testing/selftests/bpf/progs/fexit_test.c
+++ b/tools/testing/selftests/bpf/progs/fexit_test.c
@@ -6,28 +6,28 @@
 
 char _license[] SEC("license") = "GPL";
 
-static volatile __u64 test1_result;
+__u64 test1_result = 0;
 BPF_TRACE_2("fexit/bpf_fentry_test1", test1, int, a, int, ret)
 {
 	test1_result = a == 1 && ret == 2;
 	return 0;
 }
 
-static volatile __u64 test2_result;
+__u64 test2_result = 0;
 BPF_TRACE_3("fexit/bpf_fentry_test2", test2, int, a, __u64, b, int, ret)
 {
 	test2_result = a == 2 && b == 3 && ret == 5;
 	return 0;
 }
 
-static volatile __u64 test3_result;
+__u64 test3_result = 0;
 BPF_TRACE_4("fexit/bpf_fentry_test3", test3, char, a, int, b, __u64, c, int, ret)
 {
 	test3_result = a == 4 && b == 5 && c == 6 && ret == 15;
 	return 0;
 }
 
-static volatile __u64 test4_result;
+__u64 test4_result = 0;
 BPF_TRACE_5("fexit/bpf_fentry_test4", test4,
 	    void *, a, char, b, int, c, __u64, d, int, ret)
 {
@@ -37,7 +37,7 @@ BPF_TRACE_5("fexit/bpf_fentry_test4", test4,
 	return 0;
 }
 
-static volatile __u64 test5_result;
+__u64 test5_result = 0;
 BPF_TRACE_6("fexit/bpf_fentry_test5", test5,
 	    __u64, a, void *, b, short, c, int, d, __u64, e, int, ret)
 {
@@ -46,7 +46,7 @@ BPF_TRACE_6("fexit/bpf_fentry_test5", test5,
 	return 0;
 }
 
-static volatile __u64 test6_result;
+__u64 test6_result = 0;
 BPF_TRACE_7("fexit/bpf_fentry_test6", test6,
 	    __u64, a, void *, b, short, c, int, d, void *, e, __u64, f,
 	    int, ret)
diff --git a/tools/testing/selftests/bpf/progs/test_mmap.c b/tools/testing/selftests/bpf/progs/test_mmap.c
index 0d2ec9fbcf61..e808791b7047 100644
--- a/tools/testing/selftests/bpf/progs/test_mmap.c
+++ b/tools/testing/selftests/bpf/progs/test_mmap.c
@@ -15,8 +15,8 @@ struct {
 	__type(value, __u64);
 } data_map SEC(".maps");
 
-static volatile __u64 in_val;
-static volatile __u64 out_val;
+__u64 in_val = 0;
+__u64 out_val = 0;
 
 SEC("raw_tracepoint/sys_enter")
 int test_mmap(void *ctx)