Kirill A. Shutemov 70f1528747 x86/mm: Fix regression with huge pages on PAE ... Recent PAT patchset has caused issue on 32-bit PAE machines: page:eea45000 count:0 mapcount:-128 mapping: (null) index:0x0 flags: 0x40000000() page dumped because: VM_BUG_ON_PAGE(page_mapcount(page) < 0) ------------[ cut here ]------------ kernel BUG at /home/build/linux-boris/mm/huge_memory.c:1485! invalid opcode: 0000 [#1] SMP [...] Call Trace: unmap_single_vma ? __wake_up unmap_vmas unmap_region do_munmap vm_munmap SyS_munmap do_fast_syscall_32 ? __do_page_fault sysenter_past_esp Code: ... EIP: [<c11bde80>] zap_huge_pmd+0x240/0x260 SS:ESP 0068:f6459d98 The problem is in pmd_pfn_mask() and pmd_flags_mask(). These helpers use PMD_PAGE_MASK to calculate resulting mask. PMD_PAGE_MASK is 'unsigned long', not 'unsigned long long' as phys_addr_t is on 32-bit PAE (ARCH_PHYS_ADDR_T_64BIT). As a result, the upper bits of resulting mask get truncated. pud_pfn_mask() and pud_flags_mask() aren't problematic since we don't have PUD page table level on 32-bit systems, but it's reasonable to keep them consistent with PMD counterpart. Introduce PHYSICAL_PMD_PAGE_MASK and PHYSICAL_PUD_PAGE_MASK in addition to existing PHYSICAL_PAGE_MASK and reworks helpers to use them. Reported-and-Tested-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> [ Fix -Woverflow warnings from the realmode code. ] Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Toshi Kani <toshi.kani@hpe.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Jürgen Gross <jgross@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: elliott@hpe.com Cc: konrad.wilk@oracle.com Cc: linux-mm <linux-mm@kvack.org> Fixes: f70abb0fc3 ("x86/asm: Fix pud/pmd interfaces to handle large PAT bit") Link: http://lkml.kernel.org/r/1448878233-11390-2-git-send-email-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org>		2015-12-04 09:14:27 +01:00
..
asm	x86/mm: Fix regression with huge pages on PAE	2015-12-04 09:14:27 +01:00
uapi/asm	Four changes:	2015-11-12 14:34:06 -08:00