Cell OProfile: Incorrect local array size in activate spu profiling function

Updated the patch to address comments by Michael Ellerman.
Specifically, changed upper limit in for loop to
ARRAY_SIZE() macro and added a check to make sure the
number of events specified by the user, which is used as
the max for indexing various arrays, is no bigger then the
declared size of the arrays.

The size of the pm_signal_local array should be equal to the
number of SPUs being configured in the array.  Currently, the
array is of size 4 (NR_PHYS_CTRS) but being indexed by a for
loop from 0 to 7 (NUM_SPUS_PER_NODE).

Signed-off-by: Carl Love <carll@us.ibm.com>

1 files changed, 10 insertions, 3 deletions

diff --git a/arch/powerpc/oprofile/op_model_cell.c b/arch/powerpc/oprofile/op_model_cell.c
index 35141a8bc3d9..25a4ec2514a3 100644
--- a/arch/powerpc/oprofile/op_model_cell.c
+++ b/arch/powerpc/oprofile/op_model_cell.c
@@ -582,6 +582,13 @@ static int cell_reg_setup(struct op_counter_config *ctr,
 
         num_counters = num_ctrs;
 
+        if (unlikely(num_ctrs > NR_PHYS_CTRS)) {
+                printk(KERN_ERR
+                       "%s: Oprofile, number of specified events " \
+                       "exceeds number of physical counters\n",
+                       __func__);
+                return -EIO;
+        }
         pm_regs.group_control = 0;
         pm_regs.debug_bus_control = 0;
 
@@ -830,13 +837,13 @@ static int calculate_lfsr(int n)
 static int pm_rtas_activate_spu_profiling(u32 node)
 {
         int ret, i;
-        struct pm_signal pm_signal_local[NR_PHYS_CTRS];
+        struct pm_signal pm_signal_local[NUM_SPUS_PER_NODE];
 
         /*
          * Set up the rtas call to configure the debug bus to
          * route the SPU PCs.  Setup the pm_signal for each SPU
          */
-        for (i = 0; i < NUM_SPUS_PER_NODE; i++) {
+        for (i = 0; i < ARRAY_SIZE(pm_signal_local); i++) {
                 pm_signal_local[i].cpu = node;
                 pm_signal_local[i].signal_group = 41;
                 /* spu i on word (i/2) */
@@ -848,7 +855,7 @@ static int pm_rtas_activate_spu_profiling(u32 node)
 
         ret = rtas_ibm_cbe_perftools(SUBFUNC_ACTIVATE,
                                      PASSTHRU_ENABLE, pm_signal_local,
-                                     (NUM_SPUS_PER_NODE
+                                     (ARRAY_SIZE(pm_signal_local)
                                       * sizeof(struct pm_signal)));
 
         if (unlikely(ret)) {