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| author | Mark McLoughlin <markmc@redhat.com> | 2008-04-02 15:36:37 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-04-04 18:36:48 +0200 |
| commit | a684d69d15a8fafede7c5c0daac8c646bbee805c (patch) | |
| tree | 510b8f9ba8bd0d5cb23703070b342b4c05380ee3 /arch | |
| parent | f64337062c09c2c318fbcbf44ed1d739e8bc72ab (diff) | |
| download | lwn-a684d69d15a8fafede7c5c0daac8c646bbee805c.tar.gz lwn-a684d69d15a8fafede7c5c0daac8c646bbee805c.zip | |
xen: Do not pin/unpin PMD pages
i.e. with this simple test case:
int fd = open("/dev/zero", O_RDONLY);
munmap(mmap((void *)0x40000000, 0x1000_LEN, PROT_READ, MAP_PRIVATE, fd, 0), 0x1000);
close(fd);
we currently get:
kernel BUG at arch/x86/xen/enlighten.c:678!
...
EIP is at xen_release_pt+0x79/0xa9
...
Call Trace:
[<c041da25>] ? __pmd_free_tlb+0x1a/0x75
[<c047a192>] ? free_pgd_range+0x1d2/0x2b5
[<c047a2f3>] ? free_pgtables+0x7e/0x93
[<c047b272>] ? unmap_region+0xb9/0xf5
[<c047c1bd>] ? do_munmap+0x193/0x1f5
[<c047c24f>] ? sys_munmap+0x30/0x3f
[<c0408cce>] ? syscall_call+0x7/0xb
=======================
and xen complains:
(XEN) mm.c:2241:d4 Mfn 1cc37 not pinned
Further details at:
https://bugzilla.redhat.com/436453
Signed-off-by: Mark McLoughlin <markmc@redhat.com>
Cc: xen-devel@lists.xensource.com
Cc: Mark McLoughlin <markmc@redhat.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/xen/enlighten.c | 5 |
1 files changed, 2 insertions, 3 deletions
diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c index 16e2f8096a1a..f16b056e5c56 100644 --- a/arch/x86/xen/enlighten.c +++ b/arch/x86/xen/enlighten.c @@ -689,8 +689,6 @@ static void xen_alloc_ptpage(struct mm_struct *mm, u32 pfn, unsigned level) make_lowmem_page_readonly(__va(PFN_PHYS(pfn))); if (level == PT_PTE) pin_pagetable_pfn(MMUEXT_PIN_L1_TABLE, pfn); - else if (level == PT_PMD) - pin_pagetable_pfn(MMUEXT_PIN_L2_TABLE, pfn); } else /* make sure there are no stray mappings of this page */ @@ -715,7 +713,8 @@ static void xen_release_ptpage(u32 pfn, unsigned level) if (PagePinned(page)) { if (!PageHighMem(page)) { - pin_pagetable_pfn(MMUEXT_UNPIN_TABLE, pfn); + if (level == PT_PTE) + pin_pagetable_pfn(MMUEXT_UNPIN_TABLE, pfn); make_lowmem_page_readwrite(__va(PFN_PHYS(pfn))); } } |