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 5.8-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-5.8 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 3f56e14febce2c2fb0e7937c24689b2dcd2f150d 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 5611b564d3b1c..f54b2293c490f 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;