Messages in this thread | | | Date | Tue, 28 Nov 2000 01:49:05 +0100 | From | Andries Brouwer <> | Subject | Re: real_root_dev |
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On Mon, Nov 27, 2000 at 10:27:00PM +0100, Marcus Sundberg wrote:
> This reminded me of an old bug which apparently still hasn't been > fixed (not in 2.2 at least). In init/main.c we have: > > extern int rd_image_start; /* starting block # of image */ > #ifdef CONFIG_BLK_DEV_INITRD > kdev_t real_root_dev; > #endif > #endif > > int root_mountflags = MS_RDONLY; > > and then in kernel/sysctl.c: > > #ifdef CONFIG_BLK_DEV_INITRD > {KERN_REALROOTDEV, "real-root-dev", &real_root_dev, sizeof(int), > 0644, NULL, &proc_dointvec}, > #endif > > Because rd_image_start and root_mountflags are both int-aligned, > this happens to work on little endian platforms. On big endian > platforms however writing a value in the range 0-65535 to > /proc/sys/kernel/real-root-dev will place 0 in real_root_dev, > and the actual value in the two padding bytes... > > Unfortunately proc_dointvec() doesn't support shorts, so what is > the correct fix? Changing: > kdev_t real_root_dev; > into > int real_root-dev; > is a perfectly working solution, but is it acceptable?
If you compile the kernel and use an integral type for kdev_t, perhaps. On the other hand, I usually use a pointer type for kdev_t, and then this entire sysctl construction is broken.
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