Le 01/05/2019 à 11:29, Rasmus Villemoes a écrit :
The comment "No QE ever has fewer than 28 SNUMs" is false; e.g. the
MPC8309 has 14. The code path returning -EINVAL is also a recipe for
instant disaster, since the caller (qe_snums_init) uncritically
assigns the return value to the unsigned qe_num_of_snum, and would
thus proceed to attempt to copy 4GB from snum_init_46[] to the snum[]
array.
So fold the handling of the legacy fsl,qe-num-snums into
qe_snums_init, and make sure we do not end up using the snum_init_46
array in cases other than the two where we know it makes sense.
Signed-off-by: Rasmus Villemoes <rasmus.villemoes@xxxxxxxxx>
Reviewed-by: Christophe Leroy <christophe.leroy@xxxxxx>
---
drivers/soc/fsl/qe/qe.c | 46 ++++++++++++++---------------------------
1 file changed, 16 insertions(+), 30 deletions(-)
diff --git a/drivers/soc/fsl/qe/qe.c b/drivers/soc/fsl/qe/qe.c
index 325d689cbf5c..276d7d78ebfc 100644
--- a/drivers/soc/fsl/qe/qe.c
+++ b/drivers/soc/fsl/qe/qe.c
@@ -308,24 +308,33 @@ static void qe_snums_init(void)
int i;
bitmap_zero(snum_state, QE_NUM_OF_SNUM);
+ qe_num_of_snum = 28; /* The default number of snum for threads is 28 */
qe = qe_get_device_node();
if (qe) {
i = of_property_read_variable_u8_array(qe, "fsl,qe-snums",
snums, 1, QE_NUM_OF_SNUM);
- of_node_put(qe);
if (i > 0) {
+ of_node_put(qe);
qe_num_of_snum = i;
return;
}
+ /*
+ * Fall back to legacy binding of using the value of
+ * fsl,qe-num-snums to choose one of the static arrays
+ * above.
+ */
+ of_property_read_u32(qe, "fsl,qe-num-snums", &qe_num_of_snum);
+ of_node_put(qe);
}
- qe_num_of_snum = qe_get_num_of_snums();
-
- if (qe_num_of_snum == 76)
+ if (qe_num_of_snum == 76) {
snum_init = snum_init_76;
- else
+ } else if (qe_num_of_snum == 28 || qe_num_of_snum == 46) {
snum_init = snum_init_46;
-
+ } else {
+ pr_err("QE: unsupported value of fsl,qe-num-snums: %u\n", qe_num_of_snum);
+ return;
+ }
memcpy(snums, snum_init, qe_num_of_snum);
}
@@ -641,30 +650,7 @@ EXPORT_SYMBOL(qe_get_num_of_risc);
unsigned int qe_get_num_of_snums(void)
{
- struct device_node *qe;
- int size;
- unsigned int num_of_snums;
- const u32 *prop;
-
- num_of_snums = 28; /* The default number of snum for threads is 28 */
- qe = qe_get_device_node();
- if (!qe)
- return num_of_snums;
-
- prop = of_get_property(qe, "fsl,qe-num-snums", &size);
- if (prop && size == sizeof(*prop)) {
- num_of_snums = *prop;
- if ((num_of_snums < 28) || (num_of_snums > QE_NUM_OF_SNUM)) {
- /* No QE ever has fewer than 28 SNUMs */
- pr_err("QE: number of snum is invalid\n");
- of_node_put(qe);
- return -EINVAL;
- }
- }
-
- of_node_put(qe);
-
- return num_of_snums;
+ return qe_num_of_snum;
}
EXPORT_SYMBOL(qe_get_num_of_snums);
