x86/intel_rdt: Fix incorrect loop end condition

In order to determine a sane default cache allocation for a new CAT/CDP
resource group, all resource groups are checked to determine which cache
portions are available to share. At this time all possible CLOSIDs
that can be supported by the resource is checked. This is problematic
if the resource supports more CLOSIDs than another CAT/CDP resource. In
this case, the number of CLOSIDs that could be allocated are fewer than
the number of CLOSIDs that can be supported by the resource.

Limit the check of closids to that what is supported by the system based
on the minimum across all resources.

Fixes: 95f0b77ef ("x86/intel_rdt: Initialize new resource group with sane defaults")
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: "H Peter Anvin" <hpa@zytor.com>
Cc: "Tony Luck" <tony.luck@intel.com>
Cc: "Xiaochen Shen" <xiaochen.shen@intel.com>
Cc: "Chen Yu" <yu.c.chen@intel.com>
Link: https://lkml.kernel.org/r/1537048707-76280-10-git-send-email-fenghua.yu@intel.com

diff --git a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
index f3231f78d69b31d4b375f0143fe37b5c9963ba6e..1b8e86a5d5e11ef3f0742a512fd652086c0fcf6f 100644 (file)
--- a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
+++ b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
@@ -2370,7 +2370,7 @@ static int rdtgroup_init_alloc(struct rdtgroup *rdtgrp)
                        d->new_ctrl = r->cache.shareable_bits;
                        used_b = r->cache.shareable_bits;
                        ctrl = d->ctrl_val;
-                       for (i = 0; i < r->num_closid; i++, ctrl++) {
+                       for (i = 0; i < closids_supported(); i++, ctrl++) {
                                if (closid_allocated(i) && i != closid) {
                                        mode = rdtgroup_mode_by_closid(i);
                                        if (mode == RDT_MODE_PSEUDO_LOCKSETUP)