bpf: print log_buf field as a string

* bpf.c (BEGIN_BPF_CMD_DECODER(BPF_PROG_LOAD)): Print log_buf field
as a string.
* tests/bpf.c: Update expected output.

Co-Authored-by: Dmitry V. Levin <ldv@altlinux.org>

diff --git a/bpf.c b/bpf.c
index 83c6ea8d5fb5365dcd8a56b0b8cabcbae701a57e..98043de25cdd1c7e3367da098fe2bdc7c2ee39da 100644 (file)
--- a/bpf.c
+++ b/bpf.c
@@ -286,7 +286,9 @@ BEGIN_BPF_CMD_DECODER(BPF_PROG_LOAD)
                break;
        PRINT_FIELD_U(", ", attr, log_level);
        PRINT_FIELD_U(", ", attr, log_size);
-       PRINT_FIELD_ADDR64(", ", attr, log_buf);
+       tprintf(", log_buf=");
+       print_big_u64_addr(attr.log_buf);
+       printstr_ex(tcp, attr.log_buf, attr.log_size, QUOTE_0_TERMINATED);
 
        /* kern_version field was added in Linux commit v4.1-rc1~84^2~50.  */
        if (len <= offsetof(struct BPF_PROG_LOAD_struct, kern_version))

diff --git a/tests/bpf.c b/tests/bpf.c
index 74e02053159a2f31b6ea411c4d07d394f9e0e932..15ce7132d50baa536aabeb830cc727e95a71ba6b 100644 (file)
--- a/tests/bpf.c
+++ b/tests/bpf.c
@@ -501,9 +501,29 @@ static const struct bpf_insn insns[] = {
        },
 };
 static const char license[] = "GPL";
-static char log_buf[4096];
 static const char pathname[] = "/sys/fs/bpf/foo/bar";
 
+static char *log_buf;
+/*
+ * This has to be a macro, otherwise the compiler complains that
+ * initializer element is not constant.
+ */
+#define log_buf_size 4096U
+
+static inline char *
+get_log_buf(void)
+{
+       if (!log_buf)
+               log_buf = tail_alloc(log_buf_size);
+       return log_buf;
+}
+
+static inline char *
+get_log_buf_tail(void)
+{
+       return get_log_buf() + log_buf_size;
+}
+
 #if VERBOSE
 # define INSNS_FMT \
        "[{code=BPF_JMP|BPF_K|BPF_EXIT, dst_reg=BPF_REG_10" \
@@ -518,9 +538,10 @@ static void
 init_BPF_PROG_LOAD_attr3(struct bpf_attr_check *check)
 {
        struct BPF_PROG_LOAD_struct *attr = &check->data.BPF_PROG_LOAD_data;
+
        attr->insns = (uintptr_t) insns;
        attr->license = (uintptr_t) license;
-       attr->log_buf = (uintptr_t) log_buf;
+       attr->log_buf = (uintptr_t) get_log_buf_tail();
 }
 
 static void
@@ -528,34 +549,39 @@ print_BPF_PROG_LOAD_attr3(const struct bpf_attr_check *check, unsigned long addr
 {
        printf("prog_type=BPF_PROG_TYPE_SOCKET_FILTER, insn_cnt=%u"
               ", insns=" INSNS_FMT ", license=\"%s\", log_level=2718281828"
-              ", log_size=4096, log_buf=%p"
+              ", log_size=%u, log_buf=%p"
               ", kern_version=KERNEL_VERSION(51966, 240, 13)"
               ", prog_flags=0x2 /* BPF_F_??? */"
               ", prog_name=\"0123456789abcde\"..., prog_ifindex=3203399405",
-              (unsigned int) ARRAY_SIZE(insns), INSNS_ARG, license, log_buf);
+              (unsigned int) ARRAY_SIZE(insns), INSNS_ARG, license,
+              log_buf_size, get_log_buf_tail());
 }
 
 static void
 init_BPF_PROG_LOAD_attr4(struct bpf_attr_check *check)
 {
        struct BPF_PROG_LOAD_struct *attr = &check->data.BPF_PROG_LOAD_data;
+
        attr->insns = (uintptr_t) insns;
        attr->license = (uintptr_t) license;
-       attr->log_buf = (uintptr_t) log_buf;
+       attr->log_buf = (uintptr_t) get_log_buf();
        attr->prog_ifindex = ifindex_lo();
+
+       strncpy(log_buf, "log test", 9);
 }
 
 static void
 print_BPF_PROG_LOAD_attr4(const struct bpf_attr_check *check, unsigned long addr)
 {
        printf("prog_type=BPF_PROG_TYPE_UNSPEC, insn_cnt=%u, insns=" INSNS_FMT
-              ", license=\"%s\", log_level=2718281828, log_size=4096"
-              ", log_buf=%p, kern_version=KERNEL_VERSION(51966, 240, 13)"
+              ", license=\"%s\", log_level=2718281828, log_size=4"
+              ", log_buf=\"log \"..."
+              ", kern_version=KERNEL_VERSION(51966, 240, 13)"
               ", prog_flags=BPF_F_STRICT_ALIGNMENT|0x2"
               ", prog_name=\"0123456789abcde\"..., prog_ifindex=%s"
               ", expected_attach_type=BPF_CGROUP_INET6_BIND",
               (unsigned int) ARRAY_SIZE(insns), INSNS_ARG,
-              license, log_buf, IFINDEX_LO_STR);
+              license, IFINDEX_LO_STR);
 }
 
 static struct bpf_attr_check BPF_PROG_LOAD_checks[] = {
@@ -591,7 +617,7 @@ static struct bpf_attr_check BPF_PROG_LOAD_checks[] = {
                        .insns = 0xffffffff00000000,
                        .license = 0xffffffff00000000,
                        .log_level = 2718281828U,
-                       .log_size = sizeof(log_buf),
+                       .log_size = log_buf_size,
                        .log_buf = 0xffffffff00000000,
                        .kern_version = 0xcafef00d,
                        .prog_flags = 1,
@@ -603,7 +629,7 @@ static struct bpf_attr_check BPF_PROG_LOAD_checks[] = {
                       ", insns=" BIG_ADDR("0xffffffff00000000", "NULL")
                       ", license=" BIG_ADDR("0xffffffff00000000", "NULL")
                       ", log_level=2718281828, log_size=4096"
-                      ", log_buf=0xffffffff00000000"
+                      ", log_buf=" BIG_ADDR("0xffffffff00000000", "NULL")
                       ", kern_version=KERNEL_VERSION(51966, 240, 13)"
                       ", prog_flags=BPF_F_STRICT_ALIGNMENT"
                       ", prog_name=\"fedcba987654321\"",
@@ -613,7 +639,7 @@ static struct bpf_attr_check BPF_PROG_LOAD_checks[] = {
                        .prog_type = 1,
                        .insn_cnt = ARRAY_SIZE(insns),
                        .log_level = 2718281828U,
-                       .log_size = sizeof(log_buf),
+                       .log_size = log_buf_size,
                        .kern_version = 0xcafef00d,
                        .prog_flags = 2,
                        .prog_name = "0123456789abcdef",
@@ -628,7 +654,7 @@ static struct bpf_attr_check BPF_PROG_LOAD_checks[] = {
                        .prog_type = 0,
                        .insn_cnt = ARRAY_SIZE(insns),
                        .log_level = 2718281828U,
-                       .log_size = sizeof(log_buf),
+                       .log_size = 4,
                        .kern_version = 0xcafef00d,
                        .prog_flags = 3,
                        .prog_name = "0123456789abcdef",