From 03eb578b37659e10bed14c2d9e7cc45dfe24123b Mon Sep 17 00:00:00 2001 From: Tony Luck Date: Wed, 17 Dec 2025 09:20:48 -0800 Subject: [PATCH] x86,fs/resctrl: Improve domain type checking Every resctrl resource has a list of domain structures. struct rdt_ctrl_domain and struct rdt_mon_domain both begin with struct rdt_domain_hdr with rdt_domain_hdr::type used in validity checks before accessing the domain of a particular type. Add the resource id to struct rdt_domain_hdr in preparation for a new monitoring domain structure that will be associated with a new monitoring resource. Improve existing domain validity checks with a new helper domain_header_is_valid() that checks both domain type and resource id. domain_header_is_valid() should be used before every call to container_of() that accesses a domain structure. Signed-off-by: Tony Luck Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Reinette Chatre Link: https://lore.kernel.org/20251217172121.12030-1-tony.luck@intel.com --- arch/x86/kernel/cpu/resctrl/core.c | 10 ++++++---- fs/resctrl/ctrlmondata.c | 2 +- include/linux/resctrl.h | 9 +++++++++ 3 files changed, 16 insertions(+), 5 deletions(-) diff --git a/arch/x86/kernel/cpu/resctrl/core.c b/arch/x86/kernel/cpu/resctrl/core.c index 3792ab4819dc6..0b8b7b8697a72 100644 --- a/arch/x86/kernel/cpu/resctrl/core.c +++ b/arch/x86/kernel/cpu/resctrl/core.c @@ -464,7 +464,7 @@ static void domain_add_cpu_ctrl(int cpu, struct rdt_resource *r) hdr = resctrl_find_domain(&r->ctrl_domains, id, &add_pos); if (hdr) { - if (WARN_ON_ONCE(hdr->type != RESCTRL_CTRL_DOMAIN)) + if (!domain_header_is_valid(hdr, RESCTRL_CTRL_DOMAIN, r->rid)) return; d = container_of(hdr, struct rdt_ctrl_domain, hdr); @@ -481,6 +481,7 @@ static void domain_add_cpu_ctrl(int cpu, struct rdt_resource *r) d = &hw_dom->d_resctrl; d->hdr.id = id; d->hdr.type = RESCTRL_CTRL_DOMAIN; + d->hdr.rid = r->rid; cpumask_set_cpu(cpu, &d->hdr.cpu_mask); rdt_domain_reconfigure_cdp(r); @@ -520,7 +521,7 @@ static void domain_add_cpu_mon(int cpu, struct rdt_resource *r) hdr = resctrl_find_domain(&r->mon_domains, id, &add_pos); if (hdr) { - if (WARN_ON_ONCE(hdr->type != RESCTRL_MON_DOMAIN)) + if (!domain_header_is_valid(hdr, RESCTRL_MON_DOMAIN, r->rid)) return; d = container_of(hdr, struct rdt_mon_domain, hdr); @@ -538,6 +539,7 @@ static void domain_add_cpu_mon(int cpu, struct rdt_resource *r) d = &hw_dom->d_resctrl; d->hdr.id = id; d->hdr.type = RESCTRL_MON_DOMAIN; + d->hdr.rid = r->rid; ci = get_cpu_cacheinfo_level(cpu, RESCTRL_L3_CACHE); if (!ci) { pr_warn_once("Can't find L3 cache for CPU:%d resource %s\n", cpu, r->name); @@ -598,7 +600,7 @@ static void domain_remove_cpu_ctrl(int cpu, struct rdt_resource *r) return; } - if (WARN_ON_ONCE(hdr->type != RESCTRL_CTRL_DOMAIN)) + if (!domain_header_is_valid(hdr, RESCTRL_CTRL_DOMAIN, r->rid)) return; d = container_of(hdr, struct rdt_ctrl_domain, hdr); @@ -644,7 +646,7 @@ static void domain_remove_cpu_mon(int cpu, struct rdt_resource *r) return; } - if (WARN_ON_ONCE(hdr->type != RESCTRL_MON_DOMAIN)) + if (!domain_header_is_valid(hdr, RESCTRL_MON_DOMAIN, r->rid)) return; d = container_of(hdr, struct rdt_mon_domain, hdr); diff --git a/fs/resctrl/ctrlmondata.c b/fs/resctrl/ctrlmondata.c index b2d178d3556ec..905c310de5732 100644 --- a/fs/resctrl/ctrlmondata.c +++ b/fs/resctrl/ctrlmondata.c @@ -653,7 +653,7 @@ int rdtgroup_mondata_show(struct seq_file *m, void *arg) * the resource to find the domain with "domid". */ hdr = resctrl_find_domain(&r->mon_domains, domid, NULL); - if (!hdr || WARN_ON_ONCE(hdr->type != RESCTRL_MON_DOMAIN)) { + if (!hdr || !domain_header_is_valid(hdr, RESCTRL_MON_DOMAIN, resid)) { ret = -ENOENT; goto out; } diff --git a/include/linux/resctrl.h b/include/linux/resctrl.h index 54701668b3dfc..e7c218f8d4f77 100644 --- a/include/linux/resctrl.h +++ b/include/linux/resctrl.h @@ -131,15 +131,24 @@ enum resctrl_domain_type { * @list: all instances of this resource * @id: unique id for this instance * @type: type of this instance + * @rid: resource id for this instance * @cpu_mask: which CPUs share this resource */ struct rdt_domain_hdr { struct list_head list; int id; enum resctrl_domain_type type; + enum resctrl_res_level rid; struct cpumask cpu_mask; }; +static inline bool domain_header_is_valid(struct rdt_domain_hdr *hdr, + enum resctrl_domain_type type, + enum resctrl_res_level rid) +{ + return !WARN_ON_ONCE(hdr->type != type || hdr->rid != rid); +} + /** * struct rdt_ctrl_domain - group of CPUs sharing a resctrl control resource * @hdr: common header for different domain types -- 2.47.3