mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-10-03 07:38:10 +00:00
e3e2881214
The pmd_set_huge() and pud_set_huge() functions are used from the generic ioremap() code to establish large mappings where this is possible. But the generic ioremap() code does not check whether the PMD/PUD entries are already populated with a non-leaf entry, so that any page-table pages these entries point to will be lost. Further, on x86-32 with SHARED_KERNEL_PMD=0, this causes a BUG_ON() in vmalloc_sync_one() when PMD entries are synced from swapper_pg_dir to the current page-table. This happens because the PMD entry from swapper_pg_dir was promoted to a huge-page entry while the current PGD still contains the non-leaf entry. Because both entries are present and point to a different page, the BUG_ON() triggers. This was actually triggered with pti-x32 enabled in a KVM virtual machine by the graphics driver. A real and better fix for that would be to improve the page-table handling in the generic ioremap() code. But that is out-of-scope for this patch-set and left for later work. Reported-by: David H. Gutteridge <dhgutteridge@sympatico.ca> Signed-off-by: Joerg Roedel <jroedel@suse.de> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: David Laight <David.Laight@aculab.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Eduardo Valentin <eduval@amazon.com> Cc: Greg KH <gregkh@linuxfoundation.org> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Pavel Machek <pavel@ucw.cz> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Waiman Long <llong@redhat.com> Cc: Will Deacon <will.deacon@arm.com> Cc: aliguori@amazon.com Cc: daniel.gruss@iaik.tugraz.at Cc: hughd@google.com Cc: keescook@google.com Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/20180411152437.GC15462@8bytes.org Signed-off-by: Ingo Molnar <mingo@kernel.org> |
||
|---|---|---|
| .. | ||
| amdtopology.c | ||
| cpu_entry_area.c | ||
| debug_pagetables.c | ||
| dump_pagetables.c | ||
| extable.c | ||
| fault.c | ||
| highmem_32.c | ||
| hugetlbpage.c | ||
| ident_map.c | ||
| init.c | ||
| init_32.c | ||
| init_64.c | ||
| iomap_32.c | ||
| ioremap.c | ||
| kasan_init_64.c | ||
| kaslr.c | ||
| kmmio.c | ||
| Makefile | ||
| mem_encrypt.c | ||
| mem_encrypt_boot.S | ||
| mem_encrypt_identity.c | ||
| mm_internal.h | ||
| mmap.c | ||
| mmio-mod.c | ||
| mpx.c | ||
| numa.c | ||
| numa_32.c | ||
| numa_64.c | ||
| numa_emulation.c | ||
| numa_internal.h | ||
| pageattr-test.c | ||
| pageattr.c | ||
| pat.c | ||
| pat_internal.h | ||
| pat_rbtree.c | ||
| pf_in.c | ||
| pf_in.h | ||
| pgtable.c | ||
| pgtable_32.c | ||
| physaddr.c | ||
| physaddr.h | ||
| pkeys.c | ||
| pti.c | ||
| setup_nx.c | ||
| srat.c | ||
| testmmiotrace.c | ||
| tlb.c | ||