Fix the ioctl CONS_FINDMODE and its underlying subroutine

xxx_query_mode() in the vga and vesa drivers.

- xxx_query_mode() returns 0 (success) and a positive error number.
- Copy mode information on success.
- Remove redundant structure copy.

The bug first found in -STABLE by jmg.

3 files changed, 10 insertions, 18 deletions

diff --git a/sys/dev/fb/fb.c b/sys/dev/fb/fb.c
index 59ac170..b95003e 100644
--- a/sys/dev/fb/fb.c
+++ b/sys/dev/fb/fb.c
@@ -754,14 +754,6 @@ fb_commonioctl(video_adapter_t *adp, u_long cmd, caddr_t arg)
 	case FBIO_FINDMODE:	/* find a matching video mode */
 		error = (*vidsw[adp->va_index]->query_mode)(adp, 
 				(video_info_t *)arg); 
-		if (error < 0) {
-			error = EINVAL;
-		} else {
-			error = (*vidsw[adp->va_index]->get_info)(adp, 
-					error, (video_info_t *)arg); 
-			if (error)
-				error = ENODEV;	/* shouldn't happen */
-		}
 		break;
 
 	case FBIO_GETMODE:	/* get video mode */
diff --git a/sys/dev/fb/vga.c b/sys/dev/fb/vga.c
index 6c96dae..f733e47 100644
--- a/sys/dev/fb/vga.c
+++ b/sys/dev/fb/vga.c
@@ -1441,11 +1441,10 @@ vga_get_info(video_adapter_t *adp, int mode, video_info_t *info)
 static int
 vga_query_mode(video_adapter_t *adp, video_info_t *info)
 {
-    video_info_t buf;
     int i;
 
     if (!vga_init_done)
-	return -1;
+	return ENXIO;
 
     for (i = 0; bios_vmode[i].vi_mode != EOT; ++i) {
 	if (bios_vmode[i].vi_mode == NA)
@@ -1475,11 +1474,11 @@ vga_query_mode(video_adapter_t *adp, video_info_t *info)
 		continue;
 
 	/* verify if this mode is supported on this adapter */
-	if (vga_get_info(adp, bios_vmode[i].vi_mode, &buf))
+	if (vga_get_info(adp, bios_vmode[i].vi_mode, info))
 		continue;
-	return bios_vmode[i].vi_mode;
+	return 0;
     }
-    return -1;
+    return ENODEV;
 }
 
 /*
diff --git a/sys/i386/isa/vesa.c b/sys/i386/isa/vesa.c
index a209251..ee2e463 100644
--- a/sys/i386/isa/vesa.c
+++ b/sys/i386/isa/vesa.c
@@ -937,10 +937,10 @@ vesa_query_mode(video_adapter_t *adp, video_info_t *info)
 {
 	int i;
 
-	if ((i = (*prevvidsw->query_mode)(adp, info)) != -1)
-		return i;
+	if ((*prevvidsw->query_mode)(adp, info) == 0)
+		return 0;
 	if (adp != vesa_adp)
-		return -1;
+		return ENODEV;
 
 	for (i = 0; vesa_vmode[i].vi_mode != EOT; ++i) {
 		if ((info->vi_width != 0)
@@ -965,9 +965,10 @@ vesa_query_mode(video_adapter_t *adp, video_info_t *info)
 		if ((info->vi_flags != 0)
 		    && (info->vi_flags != vesa_vmode[i].vi_flags))
 			continue;
-		return vesa_vmode[i].vi_mode;
+		*info = vesa_vmode[i];
+		return 0;
 	}
-	return -1;
+	return ENODEV;
 }
 
 static int