The patch titled drivers/char/miscc.: use a proper range for minor number dynamic allocation has been added to the -mm tree. Its filename is drivers-char-miscc-use-a-proper-range-for-minor-number-dynamic-allocation.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/SubmitChecklist when testing your code *** See http://userweb.kernel.org/~akpm/stuff/added-to-mm.txt to find out what to do about this The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/ ------------------------------------------------------ Subject: drivers/char/miscc.: use a proper range for minor number dynamic allocation From: Thadeu Lima de Souza Cascardo <cascardo@xxxxxxxxxxxxxx> The current dynamic allocation of minor number for misc devices has some drawbacks. First of all, the range for dynamic numbers include some statically allocated numbers. It goes from 63 to 0, and we have numbers in the range from 1 to 15 already allocated. Although, it gives priority to the higher and not allocated numbers, we may end up in a situation where we must reject registering a driver which got a static number because a driver got its number with dynamic allocation. Considering fs/dlm/user.c allocates as many misc devices as lockspaces are created, and that we have more than 50 users around, it's not unreasonable to reach that situation. The proposed solution uses the not yet reserved range from 64 to 127. If more devices are needed, we may push 64 to 16. Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@xxxxxxxxxxxxxx> Cc: "H. Peter Anvin" <hpa@xxxxxxxxx> Cc: Alan Cox <alan@xxxxxxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- drivers/char/misc.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff -puN drivers/char/misc.c~drivers-char-miscc-use-a-proper-range-for-minor-number-dynamic-allocation drivers/char/misc.c --- a/drivers/char/misc.c~drivers-char-miscc-use-a-proper-range-for-minor-number-dynamic-allocation +++ a/drivers/char/misc.c @@ -60,6 +60,7 @@ static DEFINE_MUTEX(misc_mtx); /* * Assigned numbers, used for dynamic minors */ +#define DYNAMIC_MINOR_BASE 64 #define DYNAMIC_MINORS 64 /* like dynamic majors */ static DECLARE_BITMAP(misc_minors, DYNAMIC_MINORS); @@ -204,7 +205,7 @@ int misc_register(struct miscdevice * mi mutex_unlock(&misc_mtx); return -EBUSY; } - misc->minor = DYNAMIC_MINORS - i - 1; + misc->minor = DYNAMIC_MINOR_BASE + i; set_bit(i, misc_minors); } @@ -213,7 +214,7 @@ int misc_register(struct miscdevice * mi misc->this_device = device_create(misc_class, misc->parent, dev, misc, "%s", misc->name); if (IS_ERR(misc->this_device)) { - int i = DYNAMIC_MINORS - misc->minor - 1; + int i = misc->minor - DYNAMIC_MINOR_BASE; if (i < DYNAMIC_MINORS && i >= 0) clear_bit(i, misc_minors); err = PTR_ERR(misc->this_device); @@ -242,7 +243,7 @@ int misc_register(struct miscdevice * mi int misc_deregister(struct miscdevice *misc) { - int i = DYNAMIC_MINORS - misc->minor - 1; + int i = misc->minor - DYNAMIC_MINOR_BASE; if (list_empty(&misc->list)) return -EINVAL; _ Patches currently in -mm which might be from cascardo@xxxxxxxxxxxxxx are linux-next.patch cmpc_acpi-add-support-for-classmate-pc-acpi-devices.patch cmpc_acpi-add-support-for-classmate-pc-acpi-devices-fix.patch cmpc_acpi-add-support-for-classmate-pc-acpi-devices-depends-on-acpi.patch misc-remove-mac-pmu-function-declaration-from-misc-device-class.patch drivers-char-miscc-clear-allocation-bit-in-minor-bitmap-when-device-register-fails.patch drivers-char-miscc-use-bitmap-bitops-functions-for-dynamic-minor-number-allocation.patch drivers-char-miscc-use-a-proper-range-for-minor-number-dynamic-allocation.patch spidev-use-declare_bitmap-instead-of-declaring-the-array.patch spidev-use-declare_bitmap-instead-of-declaring-the-array-checkpatch-fixes.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html