Re: [PATCH bpf-next v2 3/3] samples: bpf: syscal_nrs: use mmap2 if defined

From: Jonathan Lemon
Date: Mon Aug 19 2019 - 17:17:28 EST




On 15 Aug 2019, at 5:13, Ivan Khoronzhuk wrote:

> For arm32 xdp sockets mmap2 is preferred, so use it if it's defined.
> Declaration of __NR_mmap can be skipped and it breaks build.
>
> Signed-off-by: Ivan Khoronzhuk <ivan.khoronzhuk@xxxxxxxxxx>

Acked-by: Jonathan Lemon <jonathan.lemon@xxxxxxxxx>


> ---
> samples/bpf/syscall_nrs.c | 6 ++++++
> samples/bpf/tracex5_kern.c | 13 +++++++++++++
> 2 files changed, 19 insertions(+)
>
> diff --git a/samples/bpf/syscall_nrs.c b/samples/bpf/syscall_nrs.c
> index 516e255cbe8f..88f940052450 100644
> --- a/samples/bpf/syscall_nrs.c
> +++ b/samples/bpf/syscall_nrs.c
> @@ -9,5 +9,11 @@ void syscall_defines(void)
> COMMENT("Linux system call numbers.");
> SYSNR(__NR_write);
> SYSNR(__NR_read);
> +#ifdef __NR_mmap2
> + SYSNR(__NR_mmap2);
> +#endif
> +#ifdef __NR_mmap
> SYSNR(__NR_mmap);
> +#endif
> +
> }
> diff --git a/samples/bpf/tracex5_kern.c b/samples/bpf/tracex5_kern.c
> index f57f4e1ea1ec..35cb0eed3be5 100644
> --- a/samples/bpf/tracex5_kern.c
> +++ b/samples/bpf/tracex5_kern.c
> @@ -68,12 +68,25 @@ PROG(SYS__NR_read)(struct pt_regs *ctx)
> return 0;
> }
>
> +#ifdef __NR_mmap2
> +PROG(SYS__NR_mmap2)(struct pt_regs *ctx)
> +{
> + char fmt[] = "mmap2\n";
> +
> + bpf_trace_printk(fmt, sizeof(fmt));
> + return 0;
> +}
> +#endif
> +
> +#ifdef __NR_mmap
> PROG(SYS__NR_mmap)(struct pt_regs *ctx)
> {
> char fmt[] = "mmap\n";
> +
> bpf_trace_printk(fmt, sizeof(fmt));
> return 0;
> }
> +#endif
>
> char _license[] SEC("license") = "GPL";
> u32 _version SEC("version") = LINUX_VERSION_CODE;
> --
> 2.17.1