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| author | Gautham R. Shenoy <ego@linux.vnet.ibm.com> | 2019-03-08 21:03:24 +0530 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2019-03-27 10:40:09 +1100 |
| commit | ce9afe08e71e3f7d64f337a6e932e50849230fc2 (patch) | |
| tree | 635284ce4f44c79dbe34d76d0d20d7d57a0ddd37 | |
| parent | d9470757398a700d9450a43508000bcfd010c7a4 (diff) | |
| download | linux-0-day-ce9afe08e71e3f7d64f337a6e932e50849230fc2.tar.gz linux-0-day-ce9afe08e71e3f7d64f337a6e932e50849230fc2.tar.xz | |
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>
| -rw-r--r-- | arch/powerpc/platforms/pseries/pseries_energy.c | 27 |
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 6ed22127391b6..921f12182f3e0 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; |