On 12/29/20 2:23 PM, Matthew Wilcox wrote: > On Tue, Dec 29, 2020 at 01:26:34PM -0800, Randy Dunlap wrote: >> UBSAN reports an invalid shift size: >> >> mr-fox kernel: UBSAN: shift-out-of-bounds in ./include/linux/log2.h:57:13 >> mr-fox kernel: shift exponent 64 is too large for 64-bit type 'long unsigned int' >> >> Original report: >> https://lore.kernel.org/lkml/c6e5eb81-680f-dd5c-8a81-62041a5ce50c@xxxxxx/ >> >> Follow-up report: >> https://lore.kernel.org/lkml/0c283ea9-b446-0e40-6dc8-e9585ae171b4@xxxxxx/T/#m9b604660925f9e8a544f7453130c31d083c1e5bb >> >> >> Willy suggested that get_init_ra_size() was being called with a size of 0, >> which would cause this (instead of some Huge value), so add a check in >> that function for size == 0, and if 0, default it to 32 (pages). > > No, this is wrong. 'size' in this case is the size of the read. > And it's zero. Is this fixed by commit > 3644e2d2dda78e21edd8f5415b6d7ab03f5f54f3 > Toralf, can you test with 5.11-rc1 (or later)? thanks. -- ~Randy
