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authorReinette Chatre <reinette.chatre@intel.com>2018-12-10 14:31:13 -0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2019-11-24 08:21:09 +0100
commit2e1f151cd2d9d18fa7e444270e882916574ab8ba (patch)
parentd64b58520670b91e0606e0864e2df66f319b5711 (diff)
x86/resctrl: Fix rdt_find_domain() return value and checks
[ Upstream commit 52eb74339a6233c69f4e3794b69ea7c98eeeae1b ] rdt_find_domain() returns an ERR_PTR() that is generated from a provided domain id when the value is negative. Care needs to be taken when creating an ERR_PTR() from this value because a subsequent check using IS_ERR() expects the error to be within the MAX_ERRNO range. Using an invalid domain id as an ERR_PTR() does work at this time since this is currently always -1. Using this undocumented assumption is fragile since future users of rdt_find_domain() may not be aware of thus assumption. Two related issues are addressed: - Ensure that rdt_find_domain() always returns a valid error value by forcing the error to be -ENODEV when a negative domain id is provided. - In a few instances the return value of rdt_find_domain() is just checked for NULL - fix these to include a check of ERR_PTR. Fixes: d89b7379015f ("x86/intel_rdt/cqm: Add mon_data") Fixes: 521348b011d6 ("x86/intel_rdt: Introduce utility to obtain CDP peer") Signed-off-by: Reinette Chatre <reinette.chatre@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: fenghua.yu@intel.com Cc: gavin.hindman@intel.com Cc: jithu.joseph@intel.com Cc: x86-ml <x86@kernel.org> Link: https://lkml.kernel.org/r/b88cd4ff6a75995bf8db9b0ea546908fe50f69f3.1544479852.git.reinette.chatre@intel.com Signed-off-by: Sasha Levin <sashal@kernel.org>
3 files changed, 3 insertions, 3 deletions
diff --git a/arch/x86/kernel/cpu/intel_rdt.c b/arch/x86/kernel/cpu/intel_rdt.c
index abb71ac70443..cc43c5abd187 100644
--- a/arch/x86/kernel/cpu/intel_rdt.c
+++ b/arch/x86/kernel/cpu/intel_rdt.c
@@ -421,7 +421,7 @@ struct rdt_domain *rdt_find_domain(struct rdt_resource *r, int id,
struct list_head *l;
if (id < 0)
- return ERR_PTR(id);
+ return ERR_PTR(-ENODEV);
list_for_each(l, &r->domains) {
d = list_entry(l, struct rdt_domain, list);
diff --git a/arch/x86/kernel/cpu/intel_rdt_ctrlmondata.c b/arch/x86/kernel/cpu/intel_rdt_ctrlmondata.c
index 627e5c809b33..968ace3c6d73 100644
--- a/arch/x86/kernel/cpu/intel_rdt_ctrlmondata.c
+++ b/arch/x86/kernel/cpu/intel_rdt_ctrlmondata.c
@@ -459,7 +459,7 @@ int rdtgroup_mondata_show(struct seq_file *m, void *arg)
r = &rdt_resources_all[resid];
d = rdt_find_domain(r, domid, NULL);
- if (!d) {
+ if (IS_ERR_OR_NULL(d)) {
ret = -ENOENT;
goto out;
diff --git a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
index 0d8ea82acd93..ad64031e82dc 100644
--- a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
+++ b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
@@ -1023,7 +1023,7 @@ static int rdt_cdp_peer_get(struct rdt_resource *r, struct rdt_domain *d,
* peer RDT CDP resource. Hence the WARN.
_d_cdp = rdt_find_domain(_r_cdp, d->id, NULL);
- if (WARN_ON(!_d_cdp)) {
+ if (WARN_ON(IS_ERR_OR_NULL(_d_cdp))) {
_r_cdp = NULL;
ret = -EINVAL;