From 587edd7069b9e7dc7993d2df9371e7c37a4d2133 Mon Sep 17 00:00:00 2001 From: Tony Luck Date: Fri, 28 Jun 2024 14:56:10 -0700 Subject: [PATCH] x86/resctrl: Initialize on-stack struct rmid_read instances New semantics rely on some struct rmid_read members having NULL values to distinguish between the SNC and non-SNC scenarios. resctrl can thus no longer rely on this struct not being initialized properly. Initialize all on-stack declarations of struct rmid_read: rdtgroup_mondata_show() mbm_update() mkdir_mondata_subdir() to ensure that garbage values from the stack are not passed down to other functions. [ bp: Massage commit message. ] Signed-off-by: Tony Luck Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Reinette Chatre Tested-by: Babu Moger Link: https://lore.kernel.org/r/20240628215619.76401-11-tony.luck@intel.com --- arch/x86/kernel/cpu/resctrl/ctrlmondata.c | 3 +-- arch/x86/kernel/cpu/resctrl/monitor.c | 3 +-- arch/x86/kernel/cpu/resctrl/rdtgroup.c | 2 +- 3 files changed, 3 insertions(+), 5 deletions(-) diff --git a/arch/x86/kernel/cpu/resctrl/ctrlmondata.c b/arch/x86/kernel/cpu/resctrl/ctrlmondata.c index 3b9383612c35..4d76ff31a9e0 100644 --- a/arch/x86/kernel/cpu/resctrl/ctrlmondata.c +++ b/arch/x86/kernel/cpu/resctrl/ctrlmondata.c @@ -529,7 +529,6 @@ void mon_event_read(struct rmid_read *rr, struct rdt_resource *r, rr->evtid = evtid; rr->r = r; rr->d = d; - rr->val = 0; rr->first = first; rr->arch_mon_ctx = resctrl_arch_mon_ctx_alloc(r, evtid); if (IS_ERR(rr->arch_mon_ctx)) { @@ -557,12 +556,12 @@ int rdtgroup_mondata_show(struct seq_file *m, void *arg) { struct kernfs_open_file *of = m->private; struct rdt_domain_hdr *hdr; + struct rmid_read rr = {0}; struct rdt_mon_domain *d; u32 resid, evtid, domid; struct rdtgroup *rdtgrp; struct rdt_resource *r; union mon_data_bits md; - struct rmid_read rr; int ret = 0; rdtgrp = rdtgroup_kn_lock_live(of->kn); diff --git a/arch/x86/kernel/cpu/resctrl/monitor.c b/arch/x86/kernel/cpu/resctrl/monitor.c index ff4e74594a19..ca309c93a56b 100644 --- a/arch/x86/kernel/cpu/resctrl/monitor.c +++ b/arch/x86/kernel/cpu/resctrl/monitor.c @@ -780,9 +780,8 @@ static void update_mba_bw(struct rdtgroup *rgrp, struct rdt_mon_domain *dom_mbm) static void mbm_update(struct rdt_resource *r, struct rdt_mon_domain *d, u32 closid, u32 rmid) { - struct rmid_read rr; + struct rmid_read rr = {0}; - rr.first = false; rr.r = r; rr.d = d; diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c index 70d41a8fd788..d0443589cd86 100644 --- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c +++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c @@ -3029,10 +3029,10 @@ static int mkdir_mondata_subdir(struct kernfs_node *parent_kn, struct rdt_mon_domain *d, struct rdt_resource *r, struct rdtgroup *prgrp) { + struct rmid_read rr = {0}; union mon_data_bits priv; struct kernfs_node *kn; struct mon_evt *mevt; - struct rmid_read rr; char name[32]; int ret; -- 2.50.1