Messages in this thread Patch in this message | | | From | Andrey Borzenkov <> | Subject | Re: [PATCH][2.6.0-test3] i386 msr.c devfs support 1/2 | Date | Sun, 10 Aug 2003 18:16:48 +0400 |
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On Sunday 10 August 2003 17:58, Dave Jones wrote: > On Sun, Aug 10, 2003 at 12:51:03PM +0400, Andrey Borzenkov wrote: > > Please let me know if default permissions (644) are not appropriate. > > bogus. They should be set to 600. Non-root access to MSRs (even read > only) can cause instant lockup/reboot on some CPUs if user tries to > read non-existant MSR. >
update patch attached.
-andrey--- ../tmp/linux-2.6.0-test3/arch/i386/kernel/msr.c 2003-07-27 22:28:41.000000000 +0400 +++ linux-2.6.0-test3-smp/arch/i386/kernel/msr.c 2003-08-10 18:06:30.000000000 +0400 @@ -37,6 +37,8 @@ #include <linux/major.h> #include <linux/fs.h> +#include <linux/devfs_fs_kernel.h> + #include <asm/processor.h> #include <asm/msr.h> #include <asm/uaccess.h> @@ -263,17 +265,28 @@ static struct file_operations msr_fops = int __init msr_init(void) { + int i; + if (register_chrdev(MSR_MAJOR, "cpu/msr", &msr_fops)) { printk(KERN_ERR "msr: unable to get major %d for msr\n", MSR_MAJOR); return -EBUSY; } + + for (i = 0; i < NR_CPUS; i++) + devfs_mk_cdev(MKDEV(MSR_MAJOR, i), S_IFCHR | S_IRUSR | S_IWUSR, + "cpu/%d/msr", i); return 0; } void __exit msr_exit(void) { + int i; + + for (i = 0; i < NR_CPUS; i++) + devfs_remove("cpu/%d/msr", i); + unregister_chrdev(MSR_MAJOR, "cpu/msr"); } | |