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authorMark Rutland <mark.rutland@arm.com>2014-10-28 19:36:45 +0000
committerPaolo Bonzini <pbonzini@redhat.com>2014-11-26 14:40:42 +0100
commit7cbb87d67e38cfc55680290a706fd7517f10050d (patch)
tree3d25032bb5790da1108c431ed507137928b3113c /arch
parentb914c5b2130239fd378d1a719ab3c53f0c782be9 (diff)
arm64: KVM: fix unmapping with 48-bit VAs
Currently if using a 48-bit VA, tearing down the hyp page tables (which can happen in the absence of a GICH or GICV resource) results in the rather nasty splat below, evidently becasue we access a table that doesn't actually exist. Commit 38f791a4e499792e (arm64: KVM: Implement 48 VA support for KVM EL2 and Stage-2) added a pgd_none check to __create_hyp_mappings to account for the additional level of tables, but didn't add a corresponding check to unmap_range, and this seems to be the source of the problem. This patch adds the missing pgd_none check, ensuring we don't try to access tables that don't exist. Original splat below: kvm [1]: Using HYP init bounce page @83fe94a000 kvm [1]: Cannot obtain GICH resource Unable to handle kernel paging request at virtual address ffff7f7fff000000 pgd = ffff800000770000 [ffff7f7fff000000] *pgd=0000000000000000 Internal error: Oops: 96000004 [#1] PREEMPT SMP Modules linked in: CPU: 1 PID: 1 Comm: swapper/0 Not tainted 3.18.0-rc2+ #89 task: ffff8003eb500000 ti: ffff8003eb45c000 task.ti: ffff8003eb45c000 PC is at unmap_range+0x120/0x580 LR is at free_hyp_pgds+0xac/0xe4 pc : [<ffff80000009b768>] lr : [<ffff80000009cad8>] pstate: 80000045 sp : ffff8003eb45fbf0 x29: ffff8003eb45fbf0 x28: ffff800000736000 x27: ffff800000735000 x26: ffff7f7fff000000 x25: 0000000040000000 x24: ffff8000006f5000 x23: 0000000000000000 x22: 0000007fffffffff x21: 0000800000000000 x20: 0000008000000000 x19: 0000000000000000 x18: ffff800000648000 x17: ffff800000537228 x16: 0000000000000000 x15: 000000000000001f x14: 0000000000000000 x13: 0000000000000001 x12: 0000000000000020 x11: 0000000000000062 x10: 0000000000000006 x9 : 0000000000000000 x8 : 0000000000000063 x7 : 0000000000000018 x6 : 00000003ff000000 x5 : ffff800000744188 x4 : 0000000000000001 x3 : 0000000040000000 x2 : ffff800000000000 x1 : 0000007fffffffff x0 : 000000003fffffff Process swapper/0 (pid: 1, stack limit = 0xffff8003eb45c058) Stack: (0xffff8003eb45fbf0 to 0xffff8003eb460000) fbe0: eb45fcb0 ffff8003 0009cad8 ffff8000 fc00: 00000000 00000080 00736140 ffff8000 00736000 ffff8000 00000000 00007c80 fc20: 00000000 00000080 006f5000 ffff8000 00000000 00000080 00743000 ffff8000 fc40: 00735000 ffff8000 006d3030 ffff8000 006fe7b8 ffff8000 00000000 00000080 fc60: ffffffff 0000007f fdac1000 ffff8003 fd94b000 ffff8003 fda47000 ffff8003 fc80: 00502b40 ffff8000 ff000000 ffff7f7f fdec6000 00008003 fdac1630 ffff8003 fca0: eb45fcb0 ffff8003 ffffffff 0000007f eb45fd00 ffff8003 0009b378 ffff8000 fcc0: ffffffea 00000000 006fe000 ffff8000 00736728 ffff8000 00736120 ffff8000 fce0: 00000040 00000000 00743000 ffff8000 006fe7b8 ffff8000 0050cd48 00000000 fd00: eb45fd60 ffff8003 00096070 ffff8000 006f06e0 ffff8000 006f06e0 ffff8000 fd20: fd948b40 ffff8003 0009a320 ffff8000 00000000 00000000 00000000 00000000 fd40: 00000ae0 00000000 006aa25c ffff8000 eb45fd60 ffff8003 0017ca44 00000002 fd60: eb45fdc0 ffff8003 0009a33c ffff8000 006f06e0 ffff8000 006f06e0 ffff8000 fd80: fd948b40 ffff8003 0009a320 ffff8000 00000000 00000000 00735000 ffff8000 fda0: 006d3090 ffff8000 006aa25c ffff8000 00735000 ffff8000 006d3030 ffff8000 fdc0: eb45fdd0 ffff8003 000814c0 ffff8000 eb45fe50 ffff8003 006aaac4 ffff8000 fde0: 006ddd90 ffff8000 00000006 00000000 006d3000 ffff8000 00000095 00000000 fe00: 006a1e90 ffff8000 00735000 ffff8000 006d3000 ffff8000 006aa25c ffff8000 fe20: 00735000 ffff8000 006d3030 ffff8000 eb45fe50 ffff8003 006fac68 ffff8000 fe40: 00000006 00000006 fe293ee6 ffff8003 eb45feb0 ffff8003 004f8ee8 ffff8000 fe60: 004f8ed4 ffff8000 00735000 ffff8000 00000000 00000000 00000000 00000000 fe80: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 fea0: 00000000 00000000 00000000 00000000 00000000 00000000 000843d0 ffff8000 fec0: 004f8ed4 ffff8000 00000000 00000000 00000000 00000000 00000000 00000000 fee0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 ff00: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 ff20: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 ff40: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 ff60: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 ff80: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 ffa0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 ffc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000005 00000000 ffe0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 Call trace: [<ffff80000009b768>] unmap_range+0x120/0x580 [<ffff80000009cad4>] free_hyp_pgds+0xa8/0xe4 [<ffff80000009b374>] kvm_arch_init+0x268/0x44c [<ffff80000009606c>] kvm_init+0x24/0x260 [<ffff80000009a338>] arm_init+0x18/0x24 [<ffff8000000814bc>] do_one_initcall+0x88/0x1a0 [<ffff8000006aaac0>] kernel_init_freeable+0x148/0x1e8 [<ffff8000004f8ee4>] kernel_init+0x10/0xd4 Code: 8b000263 92628479 d1000720 eb01001f (f9400340) ---[ end trace 3bc230562e926fa4 ]--- Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Jungseok Lee <jungseoklee85@gmail.com> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch')
-rw-r--r--arch/arm/kvm/mmu.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/arch/arm/kvm/mmu.c b/arch/arm/kvm/mmu.c
index 57a403a5c22b..79d3fbfb5b0e 100644
--- a/arch/arm/kvm/mmu.c
+++ b/arch/arm/kvm/mmu.c
@@ -197,7 +197,8 @@ static void unmap_range(struct kvm *kvm, pgd_t *pgdp,
pgd = pgdp + pgd_index(addr);
do {
next = kvm_pgd_addr_end(addr, end);
- unmap_puds(kvm, pgd, addr, next);
+ if (!pgd_none(*pgd))
+ unmap_puds(kvm, pgd, addr, next);
} while (pgd++, addr = next, addr != end);
}