netdev - [PATCH bpf-next 3/5] libbpf: Add bpf

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20210821025837.1614098-4-davemarchevsky@fb.com>
Date:   Fri, 20 Aug 2021 19:58:35 -0700
From:   Dave Marchevsky <davemarchevsky@...com>
To:     <bpf@...r.kernel.org>
CC:     Alexei Starovoitov <ast@...nel.org>,
        Daniel Borkmann <daniel@...earbox.net>,
        Andrii Nakryiko <andrii@...nel.org>,
        Yonghong Song <yhs@...com>,
        Florent Revest <revest@...omium.org>, <netdev@...r.kernel.org>,
        <linux-kselftest@...r.kernel.org>,
        Dave Marchevsky <davemarchevsky@...com>
Subject: [PATCH bpf-next 3/5] libbpf: Add bpf_vprintk convenience macro

bpf_vprintk functions similarly to BPF_SEQ_PRINTF and BPF_SNPRINTF
macros elsewhere in the file - it allows use of bpf_trace_vprintk
without manual conversion of varargs to u64 array.

Like the bpf_printk macro, bpf_vprintk is meant to be the main interface
to the bpf_trace_vprintk helper and thus is uncapitalized.

Signed-off-by: Dave Marchevsky <davemarchevsky@...com>
---
 tools/lib/bpf/bpf_helpers.h | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/tools/lib/bpf/bpf_helpers.h b/tools/lib/bpf/bpf_helpers.h
index b9987c3efa3c..43c8115956c3 100644
--- a/tools/lib/bpf/bpf_helpers.h
+++ b/tools/lib/bpf/bpf_helpers.h
@@ -224,4 +224,22 @@ enum libbpf_tristate {
 		     ___param, sizeof(___param));		\
 })
 
+/*
+ * bpf_vprintk wraps the bpf_trace_printk helper with variadic arguments
+ * instead of an array of u64.
+ */
+#define bpf_vprintk(fmt, args...)				\
+({								\
+	static const char ___fmt[] = fmt;			\
+	unsigned long long ___param[___bpf_narg(args)];		\
+								\
+	_Pragma("GCC diagnostic push")				\
+	_Pragma("GCC diagnostic ignored \"-Wint-conversion\"")	\
+	___bpf_fill(___param, args);				\
+	_Pragma("GCC diagnostic pop")				\
+								\
+	bpf_trace_vprintk(___fmt, sizeof(___fmt),		\
+		     ___param, sizeof(___param));		\
+})
+
 #endif
-- 
2.30.2