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authorIan Munsie <imunsie@au1.ibm.com>2015-07-07 15:45:46 +1000
committerMichael Ellerman <mpe@ellerman.id.au>2015-07-08 15:17:46 +1000
commit5caaf5346892d1e7f0b8b7223062644f8538483f (patch)
tree320a1d7ee081de6d878e62973222d81ccbd37ea2 /drivers/misc
parent3f8dc44d88d3e86178eb9322c779c599f3745b21 (diff)
downloadlinux-5caaf5346892d1e7f0b8b7223062644f8538483f.tar.bz2
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 <imunsie@au1.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'drivers/misc')
-rw-r--r--drivers/misc/cxl/context.c10
1 files changed, 9 insertions, 1 deletions
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 */