Commit faf8c714 authored Oct 18, 2007 by Dave Young Committed by Linus Torvalds Oct 18, 2007

param_sysfs_builtin memchr argument fix



If memchr argument is longer than strlen(kp->name), there will be some
weird result.

It will casuse duplicate filenames in sysfs for the "nousb".  kernel
warning messages are as bellow:

sysfs: duplicate filename 'usbcore' can not be created
WARNING: at fs/sysfs/dir.c:416 sysfs_add_one()
 [<c01c4750>] sysfs_add_one+0xa0/0xe0
 [<c01c4ab8>] create_dir+0x48/0xb0
 [<c01c4b69>] sysfs_create_dir+0x29/0x50
 [<c024e0fb>] create_dir+0x1b/0x50
 [<c024e3b6>] kobject_add+0x46/0x150
 [<c024e2da>] kobject_init+0x3a/0x80
 [<c053b880>] kernel_param_sysfs_setup+0x50/0xb0
 [<c053b9ce>] param_sysfs_builtin+0xee/0x130
 [<c053ba33>] param_sysfs_init+0x23/0x60
 [<c024d062>] __next_cpu+0x12/0x20
 [<c052aa30>] kernel_init+0x0/0xb0
 [<c052aa30>] kernel_init+0x0/0xb0
 [<c052a856>] do_initcalls+0x46/0x1e0
 [<c01bdb12>] create_proc_entry+0x52/0x90
 [<c0158d4c>] register_irq_proc+0x9c/0xc0
 [<c01bda94>] proc_mkdir_mode+0x34/0x50
 [<c052aa30>] kernel_init+0x0/0xb0
 [<c052aa92>] kernel_init+0x62/0xb0
 [<c0104f83>] kernel_thread_helper+0x7/0x14
 =======================
kobject_add failed for usbcore with -EEXIST, don't try to register things with the same name in the same directory.
 [<c024e466>] kobject_add+0xf6/0x150
 [<c053b880>] kernel_param_sysfs_setup+0x50/0xb0
 [<c053b9ce>] param_sysfs_builtin+0xee/0x130
 [<c053ba33>] param_sysfs_init+0x23/0x60
 [<c024d062>] __next_cpu+0x12/0x20
 [<c052aa30>] kernel_init+0x0/0xb0
 [<c052aa30>] kernel_init+0x0/0xb0
 [<c052a856>] do_initcalls+0x46/0x1e0
 [<c01bdb12>] create_proc_entry+0x52/0x90
 [<c0158d4c>] register_irq_proc+0x9c/0xc0
 [<c01bda94>] proc_mkdir_mode+0x34/0x50
 [<c052aa30>] kernel_init+0x0/0xb0
 [<c052aa92>] kernel_init+0x62/0xb0
 [<c0104f83>] kernel_thread_helper+0x7/0x14
 =======================
Module 'usbcore' failed to be added to sysfs, error number -17
The system will be unstable now.

Signed-off-by: Dave Young <hidave.darkstar@gmail.com>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 8f286c33

kernel/params.c

+7 −1

Original line number	Diff line number	Diff line
		@@ -592,11 +592,17 @@ static void __init param_sysfs_builtin(void)

		for (i=0; i < __stop___param - __start___param; i++) {
		char *dot;
		size_t kplen;

		kp = &__start___param[i];
		kplen = strlen(kp->name);

		/* We do not handle args without periods. */
		dot = memchr(kp->name, '.', MAX_KBUILD_MODNAME);
		if (kplen > MAX_KBUILD_MODNAME) {
		DEBUGP("kernel parameter name is too long: %s\n", kp->name);
		continue;
		}
		dot = memchr(kp->name, '.', kplen);
		if (!dot) {
		DEBUGP("couldn't find period in %s\n", kp->name);
		continue;

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