| Message ID | 1552059204-18626-1-git-send-email-ego@linux.vnet.ibm.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | ce9afe08e71e3f7d64f337a6e932e50849230fc2 |
| Headers | show |
| Series | pseries/energy: Use OF accessor functions to read ibm, drc-indexes | expand |
| Context | Check | Description |
|---|---|---|
| snowpatch_ozlabs/apply_patch | success | Successfully applied on branch next (9580b71b5a7863c24a9bd18bcd2ad759b86b1eff) |
| snowpatch_ozlabs/build-ppc64le | success | build succeeded & removed 1 sparse warning(s) |
| snowpatch_ozlabs/build-ppc64be | success | build succeeded & removed 1 sparse warning(s) |
| snowpatch_ozlabs/build-ppc64e | success | build succeeded & removed 0 sparse warning(s) |
| snowpatch_ozlabs/build-pmac32 | success | build succeeded & removed 0 sparse warning(s) |
| snowpatch_ozlabs/checkpatch | success | total: 0 errors, 0 warnings, 0 checks, 36 lines checked |
* Gautham R Shenoy <ego@linux.vnet.ibm.com> [2019-03-08 21:03:24]: > From: "Gautham R. Shenoy" <ego@linux.vnet.ibm.com> > > 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: commit 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> > --- > arch/powerpc/platforms/pseries/pseries_energy.c | 27 ++++++++++++++++--------- > 1 file changed, 18 insertions(+), 9 deletions(-) > > diff --git a/arch/powerpc/platforms/pseries/pseries_energy.c b/arch/powerpc/platforms/pseries/pseries_energy.c > index 6ed2212..1c4d1ba 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(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; Oops! Good bugfix. We should use device tree accessors like this in all places for correct and safe code. Thanks! --Vaidy
diff --git a/arch/powerpc/platforms/pseries/pseries_energy.c b/arch/powerpc/platforms/pseries/pseries_energy.c index 6ed2212..1c4d1ba 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(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;