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| author | Changbin Du <changbin.du@intel.com> | 2017-03-16 09:45:09 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-04-12 12:42:09 +0200 |
| commit | 5e87a005ff574f9f580a8533193205331c135a74 (patch) | |
| tree | 6877765073999177faf810f93374e15cc20a85e0 /drivers/gpu | |
| parent | cccf8321af1c8c07abc83f4321d8a131b46d0af6 (diff) | |
| download | talos-obmc-linux-5e87a005ff574f9f580a8533193205331c135a74.tar.gz talos-obmc-linux-5e87a005ff574f9f580a8533193205331c135a74.zip | |
drm/i915/kvmgt: fix suspicious rcu dereference usage
commit 5180edc2421117766fcb9c2d2dc6bfaeefdeb709 upstream.
The srcu read lock must be held while accessing kvm memslots.
This patch fix below warning for function kvmgt_rw_gpa().
[ 165.345093] [ ERR: suspicious RCU usage. ]
[ 165.416538] Call Trace:
[ 165.418989] dump_stack+0x85/0xc2
[ 165.422310] lockdep_rcu_suspicious+0xd7/0x110
[ 165.426769] kvm_read_guest_page+0x195/0x1b0 [kvm]
[ 165.431574] kvm_read_guest+0x50/0x90 [kvm]
[ 165.440492] kvmgt_rw_gpa+0x43/0xa0 [kvmgt]
[ 165.444683] kvmgt_read_gpa+0x11/0x20 [kvmgt]
[ 165.449061] gtt_get_entry64+0x4d/0xc0 [i915]
[ 165.453438] ppgtt_populate_shadow_page_by_guest_entry+0x380/0xdc0 [i915]
[ 165.460254] shadow_mm+0xd1/0x460 [i915]
[ 165.472488] intel_vgpu_create_mm+0x1ab/0x210 [i915]
[ 165.477472] intel_vgpu_g2v_create_ppgtt_mm+0x5f/0xc0 [i915]
[ 165.483154] pvinfo_mmio_write+0x19b/0x1d0 [i915]
[ 165.499068] intel_vgpu_emulate_mmio_write+0x3f9/0x600 [i915]
[ 165.504827] intel_vgpu_rw+0x114/0x150 [kvmgt]
[ 165.509281] intel_vgpu_write+0x16f/0x1a0 [kvmgt]
[ 165.513993] vfio_mdev_write+0x20/0x30 [vfio_mdev]
[ 165.518793] vfio_device_fops_write+0x24/0x30 [vfio]
[ 165.523770] __vfs_write+0x28/0x120
[ 165.540529] vfs_write+0xce/0x1f0
v2: fix Cc format for stable
Signed-off-by: Changbin Du <changbin.du@intel.com>
Reviewed-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Reviewed-by: Jike Song <jike.song@intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/gpu')
| -rw-r--r-- | drivers/gpu/drm/i915/gvt/kvmgt.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/drivers/gpu/drm/i915/gvt/kvmgt.c b/drivers/gpu/drm/i915/gvt/kvmgt.c index 325cb9b55989..5f30a0716531 100644 --- a/drivers/gpu/drm/i915/gvt/kvmgt.c +++ b/drivers/gpu/drm/i915/gvt/kvmgt.c @@ -1422,7 +1422,7 @@ static int kvmgt_rw_gpa(unsigned long handle, unsigned long gpa, { struct kvmgt_guest_info *info; struct kvm *kvm; - int ret; + int idx, ret; bool kthread = current->mm == NULL; if (!handle_valid(handle)) @@ -1434,8 +1434,10 @@ static int kvmgt_rw_gpa(unsigned long handle, unsigned long gpa, if (kthread) use_mm(kvm->mm); + idx = srcu_read_lock(&kvm->srcu); ret = write ? kvm_write_guest(kvm, gpa, buf, len) : kvm_read_guest(kvm, gpa, buf, len); + srcu_read_unlock(&kvm->srcu, idx); if (kthread) unuse_mm(kvm->mm); |
