From 14f21189df33bc972455d6a0ed875aa68718d7fc Mon Sep 17 00:00:00 2001 From: Maninder Singh Date: Mon, 29 Jun 2015 16:05:11 +0530 Subject: cxl/vphb.c: Use phb pointer after NULL check static Anlaysis detected below error:- (error) Possible null pointer dereference: phb So, Use phb after NULL check. Signed-off-by: Maninder Singh Acked-by: Ian Munsie Signed-off-by: Michael Ellerman --- drivers/misc/cxl/vphb.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'drivers') diff --git a/drivers/misc/cxl/vphb.c b/drivers/misc/cxl/vphb.c index b1d1983a84a5..2eba002b580b 100644 --- a/drivers/misc/cxl/vphb.c +++ b/drivers/misc/cxl/vphb.c @@ -112,9 +112,10 @@ static int cxl_pcie_config_info(struct pci_bus *bus, unsigned int devfn, unsigned long addr; phb = pci_bus_to_host(bus); - afu = (struct cxl_afu *)phb->private_data; if (phb == NULL) return PCIBIOS_DEVICE_NOT_FOUND; + afu = (struct cxl_afu *)phb->private_data; + if (cxl_pcie_cfg_record(bus->number, devfn) > afu->crs_num) return PCIBIOS_DEVICE_NOT_FOUND; if (offset >= (unsigned long)phb->cfg_data) -- cgit v1.2.3 From 8c00d5c9d3e7452658dda55024485d52919ebfdd Mon Sep 17 00:00:00 2001 From: Daniel Axtens Date: Thu, 2 Jul 2015 15:55:21 +1000 Subject: cxl: Test the correct mmio space before unmapping Before freeing p2n, test p2n, not p1n. Signed-off-by: Daniel Axtens Acked-by: Ian Munsie Signed-off-by: Michael Ellerman --- drivers/misc/cxl/pci.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers') diff --git a/drivers/misc/cxl/pci.c b/drivers/misc/cxl/pci.c index c68ef5806dbe..32ad09705949 100644 --- a/drivers/misc/cxl/pci.c +++ b/drivers/misc/cxl/pci.c @@ -539,7 +539,7 @@ err: static void cxl_unmap_slice_regs(struct cxl_afu *afu) { - if (afu->p1n_mmio) + if (afu->p2n_mmio) iounmap(afu->p2n_mmio); if (afu->p1n_mmio) iounmap(afu->p1n_mmio); -- cgit v1.2.3 From 3f8dc44d88d3e86178eb9322c779c599f3745b21 Mon Sep 17 00:00:00 2001 From: Michael Neuling Date: Tue, 7 Jul 2015 11:01:17 +1000 Subject: cxl: Fix refcounting in kernel API Currently the kernel API AFU dev refcounting is done on context start and stop. This patch moves this refcounting to context init and release, bringing it inline with how the userspace API does it. Without this we've seen the refcounting on the AFU get out of whack between the user and kernel API usage. This causes the AFU structures to be freed when they are actually still in use. This fixes some kref warnings we've been seeing and spurious ErrIVTE IRQs. Signed-off-by: Michael Neuling Acked-by: Ian Munsie Signed-off-by: Michael Ellerman --- drivers/misc/cxl/api.c | 12 +++++------- 1 file changed, 5 insertions(+), 7 deletions(-) (limited to 'drivers') diff --git a/drivers/misc/cxl/api.c b/drivers/misc/cxl/api.c index 0c77240ae2fc..729e0851167d 100644 --- a/drivers/misc/cxl/api.c +++ b/drivers/misc/cxl/api.c @@ -23,6 +23,7 @@ struct cxl_context *cxl_dev_context_init(struct pci_dev *dev) afu = cxl_pci_to_afu(dev); + get_device(&afu->dev); ctx = cxl_context_alloc(); if (IS_ERR(ctx)) return ctx; @@ -31,6 +32,7 @@ struct cxl_context *cxl_dev_context_init(struct pci_dev *dev) rc = cxl_context_init(ctx, afu, false, NULL); if (rc) { kfree(ctx); + put_device(&afu->dev); return ERR_PTR(-ENOMEM); } cxl_assign_psn_space(ctx); @@ -60,6 +62,8 @@ int cxl_release_context(struct cxl_context *ctx) if (ctx->status != CLOSED) return -EBUSY; + put_device(&ctx->afu->dev); + cxl_context_free(ctx); return 0; @@ -159,7 +163,6 @@ int cxl_start_context(struct cxl_context *ctx, u64 wed, } ctx->status = STARTED; - get_device(&ctx->afu->dev); out: mutex_unlock(&ctx->status_mutex); return rc; @@ -175,12 +178,7 @@ EXPORT_SYMBOL_GPL(cxl_process_element); /* Stop a context. Returns 0 on success, otherwise -Errno */ int cxl_stop_context(struct cxl_context *ctx) { - int rc; - - rc = __detach_context(ctx); - if (!rc) - put_device(&ctx->afu->dev); - return rc; + return __detach_context(ctx); } EXPORT_SYMBOL_GPL(cxl_stop_context); -- cgit v1.2.3 From 5caaf5346892d1e7f0b8b7223062644f8538483f Mon Sep 17 00:00:00 2001 From: Ian Munsie Date: Tue, 7 Jul 2015 15:45:46 +1000 Subject: cxl: Fail mmap if requested mapping is larger than assigned problem state area This patch makes the mmap call fail outright if the requested region is larger than the problem state area assigned to the context so the error is reported immediately rather than waiting for an attempt to access an address out of bounds. Although we never expect users to map more than the assigned problem state area and are not aware of anyone doing this (other than for testing), this does have the potential to break users if someone has used a larger range regardless. I'm submitting it for consideration, but if this change is not considered acceptable the previous patch is sufficient to prevent access out of bounds without breaking anyone. Signed-off-by: Ian Munsie Signed-off-by: Michael Ellerman --- drivers/misc/cxl/context.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) (limited to 'drivers') diff --git a/drivers/misc/cxl/context.c b/drivers/misc/cxl/context.c index 2a4c80ac322a..6236d4a1f7ad 100644 --- a/drivers/misc/cxl/context.c +++ b/drivers/misc/cxl/context.c @@ -145,8 +145,16 @@ static const struct vm_operations_struct cxl_mmap_vmops = { */ int cxl_context_iomap(struct cxl_context *ctx, struct vm_area_struct *vma) { + u64 start = vma->vm_pgoff << PAGE_SHIFT; u64 len = vma->vm_end - vma->vm_start; - len = min(len, ctx->psn_size); + + if (ctx->afu->current_mode == CXL_MODE_DEDICATED) { + if (start + len > ctx->afu->adapter->ps_size) + return -EINVAL; + } else { + if (start + len > ctx->psn_size) + return -EINVAL; + } if (ctx->afu->current_mode != CXL_MODE_DEDICATED) { /* make sure there is a valid per process space for this AFU */ -- cgit v1.2.3 From 10a5894f2dedd8a26b3132497445b314c0d952c4 Mon Sep 17 00:00:00 2001 From: Ian Munsie Date: Tue, 7 Jul 2015 15:45:45 +1000 Subject: cxl: Fix off by one error allowing subsequent mmap page to be accessed It was discovered that if a process mmaped their problem state area they were able to access one page more than expected, potentially allowing them to access the problem state area of an unrelated process. This was due to a simple off by one error in the mmap fault handler introduced in 0712dc7e73e59d79bcead5d5520acf4e9e917e87 ("cxl: Fix issues when unmapping contexts"), which is fixed in this patch. Cc: stable@vger.kernel.org Fixes: 0712dc7e73e5 ("cxl: Fix issues when unmapping contexts") Signed-off-by: Ian Munsie Signed-off-by: Michael Ellerman --- drivers/misc/cxl/context.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'drivers') diff --git a/drivers/misc/cxl/context.c b/drivers/misc/cxl/context.c index 6236d4a1f7ad..1287148629c0 100644 --- a/drivers/misc/cxl/context.c +++ b/drivers/misc/cxl/context.c @@ -113,11 +113,11 @@ static int cxl_mmap_fault(struct vm_area_struct *vma, struct vm_fault *vmf) if (ctx->afu->current_mode == CXL_MODE_DEDICATED) { area = ctx->afu->psn_phys; - if (offset > ctx->afu->adapter->ps_size) + if (offset >= ctx->afu->adapter->ps_size) return VM_FAULT_SIGBUS; } else { area = ctx->psn_phys; - if (offset > ctx->psn_size) + if (offset >= ctx->psn_size) return VM_FAULT_SIGBUS; } -- cgit v1.2.3 From 2c069a118fe1d80c47dca84e1561045fc7f3cc9e Mon Sep 17 00:00:00 2001 From: Daniel Axtens Date: Fri, 10 Jul 2015 09:04:25 +1000 Subject: cxl: Check if afu is not null in cxl_slbia The pointer to an AFU in the adapter's list of AFUs can be null if we're in the process of removing AFUs. The afu_list_lock doesn't guard against this. Say we have 2 slices, and we're in the process of removing cxl. - We remove the AFUs in order (see cxl_remove). In cxl_remove_afu for AFU 0, we take the lock, set adapter->afu[0] = NULL, and release the lock. - Then we get an slbia. In cxl_slbia we take the lock, and set afu = adapter->afu[0], which is NULL. - Therefore our attempt to check afu->enabled will blow up. Therefore, check if afu is a null pointer before dereferencing it. Cc: stable@vger.kernel.org Signed-off-by: Daniel Axtens Acked-by: Michael Neuling Acked-by: Ian Munsie Signed-off-by: Michael Ellerman --- drivers/misc/cxl/main.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers') diff --git a/drivers/misc/cxl/main.c b/drivers/misc/cxl/main.c index 833348e2c9cb..4a164ab8b35a 100644 --- a/drivers/misc/cxl/main.c +++ b/drivers/misc/cxl/main.c @@ -73,7 +73,7 @@ static inline void cxl_slbia_core(struct mm_struct *mm) spin_lock(&adapter->afu_list_lock); for (slice = 0; slice < adapter->slices; slice++) { afu = adapter->afu[slice]; - if (!afu->enabled) + if (!afu || !afu->enabled) continue; rcu_read_lock(); idr_for_each_entry(&afu->contexts_idr, ctx, id) -- cgit v1.2.3