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From: Andrii Nakryiko <andriin@fb.com>
To: <bpf@vger.kernel.org>, <netdev@vger.kernel.org>, <ast@fb.com>,
	<daniel@iogearbox.net>
Cc: <andrii.nakryiko@gmail.com>, <kernel-team@fb.com>,
	Andrii Nakryiko <andriin@fb.com>
Subject: [PATCH bpf-next 5/7] selftests/bpf: fix test_vmlinux test to use bpf_probe_read_user()
Date: Tue, 18 Aug 2020 14:33:54 -0700	[thread overview]
Message-ID: <20200818213356.2629020-6-andriin@fb.com> (raw)
In-Reply-To: <20200818213356.2629020-1-andriin@fb.com>

The test is reading UAPI kernel structure from user-space. So it doesn't need
CO-RE relocations and has to use bpf_probe_read_user().

Fixes: acbd06206bbb ("selftests/bpf: Add vmlinux.h selftest exercising tracing of syscalls")
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
---
 tools/testing/selftests/bpf/progs/test_vmlinux.c | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/tools/testing/selftests/bpf/progs/test_vmlinux.c b/tools/testing/selftests/bpf/progs/test_vmlinux.c
index 29fa09d6a6c6..e9dfa0313d1b 100644
--- a/tools/testing/selftests/bpf/progs/test_vmlinux.c
+++ b/tools/testing/selftests/bpf/progs/test_vmlinux.c
@@ -19,12 +19,14 @@ SEC("tp/syscalls/sys_enter_nanosleep")
 int handle__tp(struct trace_event_raw_sys_enter *args)
 {
 	struct __kernel_timespec *ts;
+	long tv_nsec;
 
 	if (args->id != __NR_nanosleep)
 		return 0;
 
 	ts = (void *)args->args[0];
-	if (BPF_CORE_READ(ts, tv_nsec) != MY_TV_NSEC)
+	if (bpf_probe_read_user(&tv_nsec, sizeof(ts->tv_nsec), &ts->tv_nsec) ||
+	    tv_nsec != MY_TV_NSEC)
 		return 0;
 
 	tp_called = true;
@@ -35,12 +37,14 @@ SEC("raw_tp/sys_enter")
 int BPF_PROG(handle__raw_tp, struct pt_regs *regs, long id)
 {
 	struct __kernel_timespec *ts;
+	long tv_nsec;
 
 	if (id != __NR_nanosleep)
 		return 0;
 
 	ts = (void *)PT_REGS_PARM1_CORE(regs);
-	if (BPF_CORE_READ(ts, tv_nsec) != MY_TV_NSEC)
+	if (bpf_probe_read_user(&tv_nsec, sizeof(ts->tv_nsec), &ts->tv_nsec) ||
+	    tv_nsec != MY_TV_NSEC)
 		return 0;
 
 	raw_tp_called = true;
@@ -51,12 +55,14 @@ SEC("tp_btf/sys_enter")
 int BPF_PROG(handle__tp_btf, struct pt_regs *regs, long id)
 {
 	struct __kernel_timespec *ts;
+	long tv_nsec;
 
 	if (id != __NR_nanosleep)
 		return 0;
 
 	ts = (void *)PT_REGS_PARM1_CORE(regs);
-	if (BPF_CORE_READ(ts, tv_nsec) != MY_TV_NSEC)
+	if (bpf_probe_read_user(&tv_nsec, sizeof(ts->tv_nsec), &ts->tv_nsec) ||
+	    tv_nsec != MY_TV_NSEC)
 		return 0;
 
 	tp_btf_called = true;
-- 
2.24.1


  parent reply	other threads:[~2020-08-18 21:34 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-08-18 21:33 [PATCH bpf-next 0/7] libbpf feature probing and sanitization improvements Andrii Nakryiko
2020-08-18 21:33 ` [PATCH bpf-next 1/7] libbpf: disable -Wswitch-enum compiler warning Andrii Nakryiko
2020-08-19  1:23   ` Yonghong Song
2020-08-19  1:39     ` Andrii Nakryiko
2020-08-19  5:44       ` Yonghong Song
2020-08-18 21:33 ` [PATCH bpf-next 2/7] libbpf: make kernel feature probing lazy Andrii Nakryiko
2020-08-18 21:33 ` [PATCH bpf-next 3/7] libbpf: factor out common logic of testing and closing FD Andrii Nakryiko
2020-08-18 21:33 ` [PATCH bpf-next 4/7] libbpf: sanitize BPF program code for bpf_probe_read_{kernel,user}[_str] Andrii Nakryiko
2020-08-19  1:42   ` Yonghong Song
2020-08-19 20:11     ` Andrii Nakryiko
2020-08-19 20:15       ` Alexei Starovoitov
2020-08-19 20:23         ` Andrii Nakryiko
2020-08-18 21:33 ` Andrii Nakryiko [this message]
2020-08-18 21:33 ` [PATCH bpf-next 6/7] libbpf: switch tracing and CO-RE helper macros to bpf_probe_read_kernel() Andrii Nakryiko
2020-08-18 21:33 ` [PATCH bpf-next 7/7] libbpf: detect minimal BTF support and skip BTF loading, if missing Andrii Nakryiko
2020-08-19  0:24 ` [PATCH bpf-next 0/7] libbpf feature probing and sanitization improvements Alexei Starovoitov

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