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authorGautham R. Shenoy <ego@linux.vnet.ibm.com>2019-03-08 21:03:24 +0530
committerMichael Ellerman <mpe@ellerman.id.au>2019-03-27 10:40:09 +1100
commitce9afe08e71e3f7d64f337a6e932e50849230fc2 (patch)
tree635284ce4f44c79dbe34d76d0d20d7d57a0ddd37 /arch
parentd9470757398a700d9450a43508000bcfd010c7a4 (diff)
powerpc/pseries/energy: Use OF accessor functions to read ibm,drc-indexes
In cpu_to_drc_index() in the case when FW_FEATURE_DRC_INFO is absent, we currently use of_read_property() to obtain the pointer to the array corresponding to the property "ibm,drc-indexes". The elements of this array are of type __be32, but are accessed without any conversion to the OS-endianness, which is buggy on a Little Endian OS. Fix this by using of_property_read_u32_index() accessor function to safely read the elements of the array. Fixes: e83636ac3334 ("pseries/drc-info: Search DRC properties for CPU indexes") Cc: stable@vger.kernel.org # v4.16+ Reported-by: Pavithra R. Prakash <pavrampu@in.ibm.com> Signed-off-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com> Reviewed-by: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com> [mpe: Make the WARN_ON a WARN_ON_ONCE so it's not retriggerable] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch')
-rw-r--r--arch/powerpc/platforms/pseries/pseries_energy.c27
1 files changed, 18 insertions, 9 deletions
diff --git a/arch/powerpc/platforms/pseries/pseries_energy.c b/arch/powerpc/platforms/pseries/pseries_energy.c
index 6ed22127391b..921f12182f3e 100644
--- a/arch/powerpc/platforms/pseries/pseries_energy.c
+++ b/arch/powerpc/platforms/pseries/pseries_energy.c
@@ -77,18 +77,27 @@ static u32 cpu_to_drc_index(int cpu)
ret = drc.drc_index_start + (thread_index * drc.sequential_inc);
} else {
- const __be32 *indexes;
-
- indexes = of_get_property(dn, "ibm,drc-indexes", NULL);
- if (indexes == NULL)
- goto err_of_node_put;
+ u32 nr_drc_indexes, thread_drc_index;
/*
- * The first element indexes[0] is the number of drc_indexes
- * returned in the list. Hence thread_index+1 will get the
- * drc_index corresponding to core number thread_index.
+ * The first element of ibm,drc-indexes array is the
+ * number of drc_indexes returned in the list. Hence
+ * thread_index+1 will get the drc_index corresponding
+ * to core number thread_index.
*/
- ret = indexes[thread_index + 1];
+ rc = of_property_read_u32_index(dn, "ibm,drc-indexes",
+ 0, &nr_drc_indexes);
+ if (rc)
+ goto err_of_node_put;
+
+ WARN_ON_ONCE(thread_index > nr_drc_indexes);
+ rc = of_property_read_u32_index(dn, "ibm,drc-indexes",
+ thread_index + 1,
+ &thread_drc_index);
+ if (rc)
+ goto err_of_node_put;
+
+ ret = thread_drc_index;
}
rc = 0;