Execute the following command and exit, then execute it again, the
following error will be reported.
$ sudo ./samples/bpf/xdpsock -i ens4f2 -M
^C
$ sudo ./samples/bpf/xdpsock -i ens4f2 -M
libbpf: elf: skipping unrecognized data section(16) .eh_frame
libbpf: elf: skipping relo section(17) .rel.eh_frame for section(16) .eh_frame
libbpf: Kernel error message: XDP program already attached
ERROR: link set xdp fd failed
commit c9d27c9e8dc7 ("samples: bpf: Do not unload prog within xdpsock")
removed the unload prog code because of the presence of bpf_link. This
is fine if XDP_SHARED_UMEM is disable, but if it is enable, unload prog
is still needed.
Fixes: c9d27c9e8dc7 ("samples: bpf: Do not unload prog within xdpsock")
Signed-off-by: Wang Hai <[email protected]>
---
samples/bpf/xdpsock_user.c | 28 ++++++++++++++++++++++++++++
1 file changed, 28 insertions(+)
diff --git a/samples/bpf/xdpsock_user.c b/samples/bpf/xdpsock_user.c
index 53e300f860bb..33d0bdebbed8 100644
--- a/samples/bpf/xdpsock_user.c
+++ b/samples/bpf/xdpsock_user.c
@@ -96,6 +96,7 @@ static int opt_xsk_frame_size = XSK_UMEM__DEFAULT_FRAME_SIZE;
static int opt_timeout = 1000;
static bool opt_need_wakeup = true;
static u32 opt_num_xsks = 1;
+static u32 prog_id;
static bool opt_busy_poll;
static bool opt_reduced_cap;
@@ -461,6 +462,23 @@ static void *poller(void *arg)
return NULL;
}
+static void remove_xdp_program(void)
+{
+ u32 curr_prog_id = 0;
+
+ if (bpf_get_link_xdp_id(opt_ifindex, &curr_prog_id, opt_xdp_flags)) {
+ printf("bpf_get_link_xdp_id failed\n");
+ exit(EXIT_FAILURE);
+ }
+
+ if (prog_id == curr_prog_id)
+ bpf_set_link_xdp_fd(opt_ifindex, -1, opt_xdp_flags);
+ else if (!curr_prog_id)
+ printf("couldn't find a prog id on a given interface\n");
+ else
+ printf("program on interface changed, not removing\n");
+}
+
static void int_exit(int sig)
{
benchmark_done = true;
@@ -471,6 +489,9 @@ static void __exit_with_error(int error, const char *file, const char *func,
{
fprintf(stderr, "%s:%s:%i: errno: %d/\"%s\"\n", file, func,
line, error, strerror(error));
+
+ if (opt_num_xsks > 1)
+ remove_xdp_program();
exit(EXIT_FAILURE);
}
@@ -490,6 +511,9 @@ static void xdpsock_cleanup(void)
if (write(sock, &cmd, sizeof(int)) < 0)
exit_with_error(errno);
}
+
+ if (opt_num_xsks > 1)
+ remove_xdp_program();
}
static void swap_mac_addresses(void *data)
@@ -857,6 +881,10 @@ static struct xsk_socket_info *xsk_configure_socket(struct xsk_umem_info *umem,
if (ret)
exit_with_error(-ret);
+ ret = bpf_get_link_xdp_id(opt_ifindex, &prog_id, opt_xdp_flags);
+ if (ret)
+ exit_with_error(-ret);
+
xsk->app_stats.rx_empty_polls = 0;
xsk->app_stats.fill_fail_polls = 0;
xsk->app_stats.copy_tx_sendtos = 0;
--
2.17.1
On Mon, Jun 28, 2021 at 11:20 AM Wang Hai <[email protected]> wrote:
>
> Execute the following command and exit, then execute it again, the
> following error will be reported.
>
> $ sudo ./samples/bpf/xdpsock -i ens4f2 -M
> ^C
> $ sudo ./samples/bpf/xdpsock -i ens4f2 -M
> libbpf: elf: skipping unrecognized data section(16) .eh_frame
> libbpf: elf: skipping relo section(17) .rel.eh_frame for section(16) .eh_frame
> libbpf: Kernel error message: XDP program already attached
> ERROR: link set xdp fd failed
>
> commit c9d27c9e8dc7 ("samples: bpf: Do not unload prog within xdpsock")
> removed the unload prog code because of the presence of bpf_link. This
> is fine if XDP_SHARED_UMEM is disable, but if it is enable, unload prog
> is still needed.
Thank you Wang.
Acked-by: Magnus Karlsson <[email protected]>
> Fixes: c9d27c9e8dc7 ("samples: bpf: Do not unload prog within xdpsock")
> Signed-off-by: Wang Hai <[email protected]>
> ---
> samples/bpf/xdpsock_user.c | 28 ++++++++++++++++++++++++++++
> 1 file changed, 28 insertions(+)
>
> diff --git a/samples/bpf/xdpsock_user.c b/samples/bpf/xdpsock_user.c
> index 53e300f860bb..33d0bdebbed8 100644
> --- a/samples/bpf/xdpsock_user.c
> +++ b/samples/bpf/xdpsock_user.c
> @@ -96,6 +96,7 @@ static int opt_xsk_frame_size = XSK_UMEM__DEFAULT_FRAME_SIZE;
> static int opt_timeout = 1000;
> static bool opt_need_wakeup = true;
> static u32 opt_num_xsks = 1;
> +static u32 prog_id;
> static bool opt_busy_poll;
> static bool opt_reduced_cap;
>
> @@ -461,6 +462,23 @@ static void *poller(void *arg)
> return NULL;
> }
>
> +static void remove_xdp_program(void)
> +{
> + u32 curr_prog_id = 0;
> +
> + if (bpf_get_link_xdp_id(opt_ifindex, &curr_prog_id, opt_xdp_flags)) {
> + printf("bpf_get_link_xdp_id failed\n");
> + exit(EXIT_FAILURE);
> + }
> +
> + if (prog_id == curr_prog_id)
> + bpf_set_link_xdp_fd(opt_ifindex, -1, opt_xdp_flags);
> + else if (!curr_prog_id)
> + printf("couldn't find a prog id on a given interface\n");
> + else
> + printf("program on interface changed, not removing\n");
> +}
> +
> static void int_exit(int sig)
> {
> benchmark_done = true;
> @@ -471,6 +489,9 @@ static void __exit_with_error(int error, const char *file, const char *func,
> {
> fprintf(stderr, "%s:%s:%i: errno: %d/\"%s\"\n", file, func,
> line, error, strerror(error));
> +
> + if (opt_num_xsks > 1)
> + remove_xdp_program();
> exit(EXIT_FAILURE);
> }
>
> @@ -490,6 +511,9 @@ static void xdpsock_cleanup(void)
> if (write(sock, &cmd, sizeof(int)) < 0)
> exit_with_error(errno);
> }
> +
> + if (opt_num_xsks > 1)
> + remove_xdp_program();
> }
>
> static void swap_mac_addresses(void *data)
> @@ -857,6 +881,10 @@ static struct xsk_socket_info *xsk_configure_socket(struct xsk_umem_info *umem,
> if (ret)
> exit_with_error(-ret);
>
> + ret = bpf_get_link_xdp_id(opt_ifindex, &prog_id, opt_xdp_flags);
> + if (ret)
> + exit_with_error(-ret);
> +
> xsk->app_stats.rx_empty_polls = 0;
> xsk->app_stats.fill_fail_polls = 0;
> xsk->app_stats.copy_tx_sendtos = 0;
> --
> 2.17.1
>
Hello:
This patch was applied to bpf/bpf.git (refs/heads/master):
On Mon, 28 Jun 2021 17:18:15 +0800 you wrote:
> Execute the following command and exit, then execute it again, the
> following error will be reported.
>
> $ sudo ./samples/bpf/xdpsock -i ens4f2 -M
> ^C
> $ sudo ./samples/bpf/xdpsock -i ens4f2 -M
> libbpf: elf: skipping unrecognized data section(16) .eh_frame
> libbpf: elf: skipping relo section(17) .rel.eh_frame for section(16) .eh_frame
> libbpf: Kernel error message: XDP program already attached
> ERROR: link set xdp fd failed
>
> [...]
Here is the summary with links:
- [bpf] samples/bpf: Fix xdpsock with '-M' parameter missing unload process
https://git.kernel.org/bpf/bpf/c/2620e92ae6ed
You are awesome, thank you!
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