From: Eugene Syromyatnikov <evgsyr@gmail.com>
Date: Sun, 20 May 2018 15:57:02 +0000 (+0200)
Subject: bpf: BPF_PROG_QUERY bpf_attr.query.prog_ids printing fixes
X-Git-Tag: v4.23~103
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=c3b04cdf6e9a5ce6732c9b717b0d9f0052436ae4;p=strace

bpf: BPF_PROG_QUERY bpf_attr.query.prog_ids printing fixes

* bpf.c (BEGIN_BPF_CMD_DECODER(BPF_PROG_QUERY)): Use
print_uint32_array_member instead of print_uint64_array_member for
printing prog_ids elements (and change the type of prog_id_buf from
uint64_t to uint32_t), as they are 32-bit; use common trick with
print_big_u64_addr for handling possible ambiguity with prog_ids
address.
* tests/bpf.c (BIG_ADDR_MAYBE): New macro.
(BPF_PROG_QUERY_checks): Update expected output.
---

diff --git a/bpf.c b/bpf.c
index ba5a01ae..3a8745fd 100644
--- a/bpf.c
+++ b/bpf.c
@@ -439,7 +439,7 @@ END_BPF_CMD_DECODER(RVAL_DECODED | RVAL_FD)
 
 BEGIN_BPF_CMD_DECODER(BPF_PROG_QUERY)
 {
-	uint64_t prog_id_buf;
+	uint32_t prog_id_buf;
 
 	if (entering(tcp)) {
 		PRINT_FIELD_FD("{query={", attr, target_fd, tcp);
@@ -463,17 +463,10 @@ BEGIN_BPF_CMD_DECODER(BPF_PROG_QUERY)
 		return 0;
 	}
 
-	/*
-	 * The issue here is that we can't pass pointers bigger than
-	 * (our) kernel long ti print_array, so we opt out from decoding
-	 * the array.
-	 */
-	if (syserror(tcp) || attr.prog_ids > max_kaddr())
-		printaddr64(attr.prog_ids);
-	else
-		print_array(tcp, attr.prog_ids, attr.prog_cnt, &prog_id_buf,
-			    sizeof(prog_id_buf), umoven_or_printaddr,
-			    print_uint64_array_member, 0);
+	print_big_u64_addr(attr.prog_ids);
+	print_array(tcp, attr.prog_ids, attr.prog_cnt, &prog_id_buf,
+		    sizeof(prog_id_buf), umoven_or_printaddr,
+		    print_uint32_array_member, 0);
 
 	tprints(", prog_cnt=");
 	if (priv && priv->bpf_prog_query_stored
diff --git a/tests/bpf.c b/tests/bpf.c
index 52a560c4..96f68b34 100644
--- a/tests/bpf.c
+++ b/tests/bpf.c
@@ -51,12 +51,15 @@
 
 #if defined MPERS_IS_m32 || SIZEOF_KERNEL_LONG_T > 4
 # define BIG_ADDR(addr64_, addr32_) addr64_
+# define BIG_ADDR_MAYBE(addr_)
 #elif defined __arm__ || defined __i386__ || defined __mips__ \
    || defined __powerpc__ || defined __riscv__ || defined __s390__ \
    || defined __sparc__ || defined __tile__
 # define BIG_ADDR(addr64_, addr32_) addr64_ " or " addr32_
+# define BIG_ADDR_MAYBE(addr_) addr_ " or "
 #else
 # define BIG_ADDR(addr64_, addr32_) addr32_
+# define BIG_ADDR_MAYBE(addr_)
 #endif
 
 #ifndef HAVE_STRUCT_BPF_INSN
@@ -887,7 +890,9 @@ static const struct bpf_attr_check BPF_PROG_QUERY_checks[] = {
 		       ", attach_type=0xe /* BPF_??? */"
 		       ", query_flags=0xfffffffe /* BPF_F_QUERY_??? */"
 		       ", attach_flags=0xfffffffc /* BPF_F_??? */"
-		       ", prog_ids=0xffffffffffffffff, prog_cnt=2718281828}",
+		       ", prog_ids="
+		       BIG_ADDR("0xffffffffffffffff", "0xffffffff")
+		       ", prog_cnt=2718281828}",
 	},
 	{ /* 3 */
 		.data = { .BPF_PROG_QUERY_data = {
@@ -903,7 +908,8 @@ static const struct bpf_attr_check BPF_PROG_QUERY_checks[] = {
 		       ", attach_type=0xfeedface /* BPF_??? */"
 		       ", query_flags=BPF_F_QUERY_EFFECTIVE|0xdeadf00c"
 		       ", attach_flags=BPF_F_ALLOW_MULTI|0xbeefcafc"
-		       ", prog_ids=0xffffffffffffffff, prog_cnt=0}",
+		       ", prog_ids=" BIG_ADDR_MAYBE("0xffffffffffffffff") "[]"
+		       ", prog_cnt=0}",
 	},
 };