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authorMark McLoughlin <markmc@redhat.com>2008-04-02 15:36:37 +0100
committerIngo Molnar <mingo@elte.hu>2008-04-04 18:36:48 +0200
commita684d69d15a8fafede7c5c0daac8c646bbee805c (patch)
tree510b8f9ba8bd0d5cb23703070b342b4c05380ee3
parentf64337062c09c2c318fbcbf44ed1d739e8bc72ab (diff)
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>
-rw-r--r--arch/x86/xen/enlighten.c5
1 files changed, 2 insertions, 3 deletions
diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index 16e2f8096a1..f16b056e5c5 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)));
}
}