lkml.org 
[lkml]   [2018]   [Sep]   [18]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 4.14 085/126] iommu/ipmmu-vmsa: Fix allocation in atomic context
    Date
    4.14-stable review patch.  If anyone has any objections, please let me know.

    ------------------

    From: Geert Uytterhoeven <geert+renesas@glider.be>

    [ Upstream commit 46583e8c48c5a094ba28060615b3a7c8c576690f ]

    When attaching a device to an IOMMU group with
    CONFIG_DEBUG_ATOMIC_SLEEP=y:

    BUG: sleeping function called from invalid context at mm/slab.h:421
    in_atomic(): 1, irqs_disabled(): 128, pid: 61, name: kworker/1:1
    ...
    Call trace:
    ...
    arm_lpae_alloc_pgtable+0x114/0x184
    arm_64_lpae_alloc_pgtable_s1+0x2c/0x128
    arm_32_lpae_alloc_pgtable_s1+0x40/0x6c
    alloc_io_pgtable_ops+0x60/0x88
    ipmmu_attach_device+0x140/0x334

    ipmmu_attach_device() takes a spinlock, while arm_lpae_alloc_pgtable()
    allocates memory using GFP_KERNEL. Originally, the ipmmu-vmsa driver
    had its own custom page table allocation implementation using
    GFP_ATOMIC, hence the spinlock was fine.

    Fix this by replacing the spinlock by a mutex, like the arm-smmu driver
    does.

    Fixes: f20ed39f53145e45 ("iommu/ipmmu-vmsa: Use the ARM LPAE page table allocator")
    Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
    Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
    Signed-off-by: Joerg Roedel <jroedel@suse.de>
    Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
    Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
    ---
    drivers/iommu/ipmmu-vmsa.c | 9 ++++-----
    1 file changed, 4 insertions(+), 5 deletions(-)

    --- a/drivers/iommu/ipmmu-vmsa.c
    +++ b/drivers/iommu/ipmmu-vmsa.c
    @@ -54,7 +54,7 @@ struct ipmmu_vmsa_domain {
    struct io_pgtable_ops *iop;

    unsigned int context_id;
    - spinlock_t lock; /* Protects mappings */
    + struct mutex mutex; /* Protects mappings */
    };

    struct ipmmu_vmsa_iommu_priv {
    @@ -523,7 +523,7 @@ static struct iommu_domain *__ipmmu_doma
    if (!domain)
    return NULL;

    - spin_lock_init(&domain->lock);
    + mutex_init(&domain->mutex);

    return &domain->io_domain;
    }
    @@ -548,7 +548,6 @@ static int ipmmu_attach_device(struct io
    struct iommu_fwspec *fwspec = dev->iommu_fwspec;
    struct ipmmu_vmsa_device *mmu = priv->mmu;
    struct ipmmu_vmsa_domain *domain = to_vmsa_domain(io_domain);
    - unsigned long flags;
    unsigned int i;
    int ret = 0;

    @@ -557,7 +556,7 @@ static int ipmmu_attach_device(struct io
    return -ENXIO;
    }

    - spin_lock_irqsave(&domain->lock, flags);
    + mutex_lock(&domain->mutex);

    if (!domain->mmu) {
    /* The domain hasn't been used yet, initialize it. */
    @@ -574,7 +573,7 @@ static int ipmmu_attach_device(struct io
    } else
    dev_info(dev, "Reusing IPMMU context %u\n", domain->context_id);

    - spin_unlock_irqrestore(&domain->lock, flags);
    + mutex_unlock(&domain->mutex);

    if (ret < 0)
    return ret;

    \
     
     \ /
      Last update: 2018-09-18 01:26    [W:4.035 / U:0.040 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site