On Tue, 12 Aug 2025 at 16:36, Amir Goldstein <amir73il@xxxxxxxxx> wrote: > > On Tue, Aug 5, 2025 at 8:30 PM Miklos Szeredi <mszeredi@xxxxxxxxxx> wrote: > > + /* Make sure return value doesn't overflow in 32bit compat mode */ > > + if (in_compat_syscall() && len > MAX_RW_COUNT) > > + len = MAX_RW_COUNT; > > + > > 1. Note that generic_copy_file_checks() can already shorten len, > so maybe this should also be done there?? not sure.. I guess it doesn't really matter, since all of these functions are local. I've decided to do it directly in vfs_copy_file_range because in other cases MAX_RW_COUNTS are checked directly in vfs_... > 2. Both ->remap_file_range() and splice cases already trim to MAX_RW_COUNT > so the only remaining case for len > MAX_RW_COUNT are filesystems > that implement ->copy_file_range() and actually support copying ranges > larger than 2MB (don't know if they actually exist) > > IOW, if we do: > > if (splice || !file_out->f_op->copy_file_range || in_compat_syscall()) > len = min_t(loff_t, MAX_RW_COUNT, len); > > We will not need to repeat the same trim of len in 3 different places > in this function. Makes sense. Thanks, Miklos
