It is possible for a CXL card to have a valid PSL but no valid
AFUs. When this happens we have a valid instance of 'struct cxl'
representing the adapter but with its member 'struct cxl_afu *cxl[]'
as empty. Unfortunately at many placed within cxl code (especially
during an EEH) the elements of this array are passed on to various
other cxl functions. Which may result in kernel oops/panic when this
'struct cxl_afu *' is dereferenced.
So this patch puts a NULL check at the beginning of various cxl
functions that accept 'struct cxl_afu *' as a formal argument and are
called from with a loop of the form:
for (i = 0; i < adapter->slices; i++) {
afu = adapter->afu[i];
/* call some function with 'afu' */
}
Signed-off-by: Vaibhav Jain <vaib...@linux.vnet.ibm.com>
---
drivers/misc/cxl/api.c | 2 +-
drivers/misc/cxl/context.c | 3 +++
drivers/misc/cxl/guest.c | 4 ++++
drivers/misc/cxl/main.c | 3 +++
drivers/misc/cxl/native.c | 4 ++++
drivers/misc/cxl/pci.c | 13 ++++++++++++-
6 files changed, 27 insertions(+), 2 deletions(-)
diff --git a/drivers/misc/cxl/api.c b/drivers/misc/cxl/api.c
index 753b1a698fc4..3466ef8b9e86 100644
--- a/drivers/misc/cxl/api.c
+++ b/drivers/misc/cxl/api.c
@@ -128,7 +128,7 @@ struct cxl_context *cxl_dev_context_init(struct pci_dev
*dev)
int rc;
afu = cxl_pci_to_afu(dev);
- if (IS_ERR(afu))
+ if (IS_ERR_OR_NULL(afu))
return ERR_CAST(afu);
ctx = cxl_context_alloc();
diff --git a/drivers/misc/cxl/context.c b/drivers/misc/cxl/context.c
index 7ff315ad3692..3957e6e7d187 100644
--- a/drivers/misc/cxl/context.c
+++ b/drivers/misc/cxl/context.c
@@ -303,6 +303,9 @@ void cxl_context_detach_all(struct cxl_afu *afu)
struct cxl_context *ctx;
int tmp;
+ if (afu == NULL)
+ return;
+
mutex_lock(&afu->contexts_lock);
idr_for_each_entry(&afu->contexts_idr, ctx, tmp) {
/*
diff --git a/drivers/misc/cxl/guest.c b/drivers/misc/cxl/guest.c
index f58b4b6c79f2..8165f6f26704 100644
--- a/drivers/misc/cxl/guest.c
+++ b/drivers/misc/cxl/guest.c
@@ -760,6 +760,8 @@ static int activate_afu_directed(struct cxl_afu *afu)
static int guest_afu_activate_mode(struct cxl_afu *afu, int mode)
{
+ if (afu == NULL)
+ return -EINVAL;
if (!mode)
return 0;
if (!(mode & afu->modes_supported))
@@ -791,6 +793,8 @@ static int deactivate_afu_directed(struct cxl_afu *afu)
static int guest_afu_deactivate_mode(struct cxl_afu *afu, int mode)
{
+ if (afu == NULL)
+ return -EINVAL;
if (!mode)
return 0;
if (!(mode & afu->modes_supported))
diff --git a/drivers/misc/cxl/main.c b/drivers/misc/cxl/main.c
index c1ba0d42cbc8..296a71ca6f2e 100644
--- a/drivers/misc/cxl/main.c
+++ b/drivers/misc/cxl/main.c
@@ -271,6 +271,9 @@ struct cxl_afu *cxl_alloc_afu(struct cxl *adapter, int
slice)
int cxl_afu_select_best_mode(struct cxl_afu *afu)
{
+ if (afu == NULL)
+ return -EINVAL;
+
if (afu->modes_supported & CXL_MODE_DIRECTED)
return cxl_ops->afu_activate_mode(afu, CXL_MODE_DIRECTED);
diff --git a/drivers/misc/cxl/native.c b/drivers/misc/cxl/native.c
index 1b3d7c65ea3f..d46415b19b71 100644
--- a/drivers/misc/cxl/native.c
+++ b/drivers/misc/cxl/native.c
@@ -971,6 +971,8 @@ static int deactivate_dedicated_process(struct cxl_afu *afu)
static int native_afu_deactivate_mode(struct cxl_afu *afu, int mode)
{
+ if (afu == NULL)
+ return -EINVAL;
if (mode == CXL_MODE_DIRECTED)
return deactivate_afu_directed(afu);
if (mode == CXL_MODE_DEDICATED)
@@ -980,6 +982,8 @@ static int native_afu_deactivate_mode(struct cxl_afu *afu,
int mode)
static int native_afu_activate_mode(struct cxl_afu *afu, int mode)
{
+ if (!afu)
+ return -EINVAL;
if (!mode)
return 0;
if (!(mode & afu->modes_supported))
diff --git a/drivers/misc/cxl/pci.c b/drivers/misc/cxl/pci.c
index 758842f65a1b..8c87d9fdcf5a 100644
--- a/drivers/misc/cxl/pci.c
+++ b/drivers/misc/cxl/pci.c
@@ -1295,6 +1295,9 @@ static int pci_configure_afu(struct cxl_afu *afu, struct
cxl *adapter, struct pc
{
int rc;
+ if (afu == NULL)
+ return -EINVAL;
+
if ((rc = pci_map_slice_regs(afu, adapter, dev)))
return rc;
@@ -1341,6 +1344,10 @@ static int pci_configure_afu(struct cxl_afu *afu, struct
cxl *adapter, struct pc
static void pci_deconfigure_afu(struct cxl_afu *afu)
{
+
+ if (afu == NULL)
+ return;
+
/*
* It's okay to deconfigure when AFU is already locked, otherwise wait
* until there are no readers
@@ -2078,6 +2085,10 @@ static pci_ers_result_t cxl_vphb_error_detected(struct
cxl_afu *afu,
pci_ers_result_t result = PCI_ERS_RESULT_NEED_RESET;
pci_ers_result_t afu_result = PCI_ERS_RESULT_NEED_RESET;
+ /* Force a hotplug if an uninitiaized AFU is encountered */
+ if (afu == NULL)
+ return PCI_ERS_RESULT_DISCONNECT;
+
/* There should only be one entry, but go through the list
* anyway
*/
@@ -2330,7 +2341,7 @@ static void cxl_pci_resume(struct pci_dev *pdev)
for (i = 0; i < adapter->slices; i++) {
afu = adapter->afu[i];
- if (afu->phb == NULL)
+ if (afu == NULL || afu->phb == NULL)
continue;
list_for_each_entry(afu_dev, &afu->phb->bus->devices, bus_list)
{
--
2.14.3
