• John Starks's avatar
    mm/gup: fix gup_pud_range() for dax · fcd0ccd8
    John Starks authored
    For dax pud, pud_huge() returns true on x86. So the function works as long
    as hugetlb is configured. However, dax doesn't depend on hugetlb.
    Commit 414fd080 ("mm/gup: fix gup_pmd_range() for dax") fixed
    devmap-backed huge PMDs, but missed devmap-backed huge PUDs. Fix this as
    well.
    
    This fixes the below kernel panic:
    
    general protection fault, probably for non-canonical address 0x69e7c000cc478: 0000 [#1] SMP
    	< snip >
    Call Trace:
    <TASK>
    get_user_pages_fast+0x1f/0x40
    iov_iter_get_pages+0xc6/0x3b0
    ? mempool_alloc+0x5d/0x170
    bio_iov_iter_get_pages+0x82/0x4e0
    ? bvec_alloc+0x91/0xc0
    ? bio_alloc_bioset+0x19a/0x2a0
    blkdev_direct_IO+0x282/0x480
    ? __io_complete_rw_common+0xc0/0xc0
    ? filemap_range_has_page+0x82/0xc0
    generic_file_direct_write+0x9d/0x1a0
    ? inode_update_time+0x24/0x30
    __generic_file_write_iter+0xbd/0x1e0
    blkdev_write_iter+0xb4/0x150
    ? io_import_iovec+0x8d/0x340
    io_write+0xf9/0x300
    io_issue_sqe+0x3c3/0x1d30
    ? sysvec_reschedule_ipi+0x6c/0x80
    __io_queue_sqe+0x33/0x240
    ? fget+0x76/0xa0
    io_submit_sqes+0xe6a/0x18d0
    ? __fget_light+0xd1/0x100
    __x64_sys_io_uring_enter+0x199/0x880
    ? __context_tracking_enter+0x1f/0x70
    ? irqentry_exit_to_user_mode+0x24/0x30
    ? irqentry_exit+0x1d/0x30
    ? __context_tracking_exit+0xe/0x70
    do_syscall_64+0x3b/0x90
    entry_SYSCALL_64_after_hwframe+0x61/0xcb
    RIP: 0033:0x7fc97c11a7be
    	< snip >
    </TASK>
    ---[ end trace 48b2e0e67debcaeb ]---
    RIP: 0010:internal_get_user_pages_fast+0x340/0x990
    	< snip >
    Kernel panic - not syncing: Fatal exception
    Kernel Offset: disabled
    
    Link: https://lkml.kernel.org/r/1670392853-28252-1-git-send-email-ssengar@linux.microsoft.com
    Fixes: 414fd080 ("mm/gup: fix gup_pmd_range() for dax")
    Signed-off-by: default avatarJohn Starks <jostarks@microsoft.com>
    Signed-off-by: default avatarSaurabh Sengar <ssengar@linux.microsoft.com>
    Cc: Jan Kara <jack@suse.cz>
    Cc: Yu Zhao <yuzhao@google.com>
    Cc: Jason Gunthorpe <jgg@nvidia.com>
    Cc: John Hubbard <jhubbard@nvidia.com>
    Cc: David Hildenbrand <david@redhat.com>
    Cc: Dan Williams <dan.j.williams@intel.com>
    Cc: Alistair Popple <apopple@nvidia.com>
    Cc: <stable@vger.kernel.org>
    Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
    fcd0ccd8
gup.c 92.8 KB