Patch "selftests/bpf: Fix test_vmlinux test to use bpf_probe_read_user()" has been added to the 5.9-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    selftests/bpf: Fix test_vmlinux test to use bpf_probe_read_user()

to the 5.9-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     selftests-bpf-fix-test_vmlinux-test-to-use-bpf_probe.patch
and it can be found in the queue-5.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 956ec6fb12bb9b783c502163e0bbdaf341a62c8c
Author: Andrii Nakryiko <andriin@xxxxxx>
Date:   Tue Aug 18 14:33:54 2020 -0700

    selftests/bpf: Fix test_vmlinux test to use bpf_probe_read_user()
    
    [ Upstream commit 02f47faa25db134f6043fb6b12a68b5d4c980bb6 ]
    
    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@xxxxxx>
    Signed-off-by: Alexei Starovoitov <ast@xxxxxxxxxx>
    Link: https://lore.kernel.org/bpf/20200818213356.2629020-6-andriin@xxxxxx
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/tools/testing/selftests/bpf/progs/test_vmlinux.c b/tools/testing/selftests/bpf/progs/test_vmlinux.c
index 29fa09d6a6c6d..e9dfa0313d1bb 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;