net/bpfilter: fix dprintf usage for /dev/kmsg (13d0f7b8) · Commits · 戴 / test

The bpfilter UMH code was recently changed to log its informative messages to /dev/kmsg, however this interface doesn't support SEEK_CUR yet, used by dprintf(). As result dprintf() returns -EINVAL and doesn't log anything. However there already had some discussions about supporting SEEK_CUR into /dev/kmsg interface in the past it wasn't concluded. Since the only user of that from userspace perspective inside the kernel is the bpfilter UMH (userspace) module it's better to correct it here instead waiting a conclusion on the interface. Fixes: ("net: bpfilter: print umh messages to /dev/kmsg") Signed-off-by:

Bruno Meneguele <bmeneg@redhat.com> Signed-off-by:

David S. Miller <davem@davemloft.net>

net/bpfilter/main.c

+8 −6

Original line number	Diff line number	Diff line
		@@ -10,7 +10,7 @@
		#include <asm/unistd.h>
		#include "msgfmt.h"

		int debug_fd;
		FILE *debug_f;

		static int handle_get_cmd(struct mbox_request *cmd)
		{
		@@ -35,9 +35,10 @@ static void loop(void)
		struct mbox_reply reply;
		int n;

		fprintf(debug_f, "testing the buffer\n");
		n = read(0, &req, sizeof(req));
		if (n != sizeof(req)) {
		dprintf(debug_fd, "invalid request %d\n", n);
		fprintf(debug_f, "invalid request %d\n", n);
		return;
		}

		@@ -47,7 +48,7 @@ static void loop(void)

		n = write(1, &reply, sizeof(reply));
		if (n != sizeof(reply)) {
		dprintf(debug_fd, "reply failed %d\n", n);
		fprintf(debug_f, "reply failed %d\n", n);
		return;
		}
		}
		@@ -55,9 +56,10 @@ static void loop(void)

		int main(void)
		{
		debug_fd = open("/dev/kmsg", 00000002);
		dprintf(debug_fd, "Started bpfilter\n");
		debug_f = fopen("/dev/kmsg", "w");
		setvbuf(debug_f, 0, _IOLBF, 0);
		fprintf(debug_f, "Started bpfilter\n");
		loop();
		close(debug_fd);
		fclose(debug_f);
		return 0;
		}

Admin message