• Max Filippov's avatar
    xtensa: fix high memory/reserved memory collision · 6ac5a11d
    Max Filippov authored
    Xtensa memory initialization code frees high memory pages without
    checking whether they are in the reserved memory regions or not. That
    results in invalid value of totalram_pages and duplicate page usage by
    CMA and highmem. It produces a bunch of BUGs at startup looking like
    this:
    
    BUG: Bad page state in process swapper  pfn:70800
    page:be60c000 count:0 mapcount:-127 mapping:  (null) index:0x1
    flags: 0x80000000()
    raw: 80000000 00000000 00000001 ffffff80 00000000 be60c014 be60c014 0000000a
    page dumped because: nonzero mapcount
    Modules linked in:
    CPU: 0 PID: 1 Comm: swapper Tainted: G    B            4.16.0-rc1-00015-g7928b2cb-dirty #23
    Stack:
     bd839d33 00000000 00000018 ba97b64c a106578c bd839d70 be60c000 00000000
     a1378054 bd86a000 00000003 ba97b64c a1066166 bd839da0 be60c000 ffe00000
     a1066b58 bd839dc0 be504000 00000000 000002f4 bd838000 00000000 0000001e
    Call Trace:
     [<a1065734>] bad_page+0xac/0xd0
     [<a106578c>] free_pages_check_bad+0x34/0x4c
     [<a1066166>] __free_pages_ok+0xae/0x14c
     [<a1066b58>] __free_pages+0x30/0x64
     [<a1365de5>] init_cma_reserved_pageblock+0x35/0x44
     [<a13682dc>] cma_init_reserved_areas+0xf4/0x148
     [<a10034b8>] do_one_initcall+0x80/0xf8
     [<a1361c16>] kernel_init_freeable+0xda/0x13c
     [<a125b59d>] kernel_init+0x9/0xd0
     [<a1004304>] ret_from_kernel_thread+0xc/0x18
    
    Only free high memory pages that are not reserved.
    
    Cc: stable@vger.kernel.org
    Signed-off-by: default avatarMax Filippov <jcmvbkbc@gmail.com>
    6ac5a11d
init.c 6.2 KB