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| author | Jithu Joseph <jithu.joseph@intel.com> | 2018-10-12 15:51:01 -0700 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2018-10-19 14:54:28 +0200 |
| commit | b61b8bba18fe2b63d38fdaf9b83de25e2d787dfe (patch) | |
| tree | 08cd45e0ebebb2d96b0073ce1d858d695c075a44 /arch/x86/kernel/cpu/intel_rdt_ctrlmondata.c | |
| parent | 2a7adf6ce643fdeec051dc88e5250b08c83bbb67 (diff) | |
| download | kernel_replicant_linux-b61b8bba18fe2b63d38fdaf9b83de25e2d787dfe.tar.gz kernel_replicant_linux-b61b8bba18fe2b63d38fdaf9b83de25e2d787dfe.tar.bz2 kernel_replicant_linux-b61b8bba18fe2b63d38fdaf9b83de25e2d787dfe.zip | |
x86/intel_rdt: Prevent pseudo-locking from using stale pointers
When the last CPU in an rdt_domain goes offline, its rdt_domain struct gets
freed. Current pseudo-locking code is unaware of this scenario and tries to
dereference the freed structure in a few places.
Add checks to prevent pseudo-locking code from doing this.
While further work is needed to seamlessly restore resource groups (not
just pseudo-locking) to their configuration when the domain is brought back
online, the immediate issue of invalid pointers is addressed here.
Fixes: f4e80d67a5274 ("x86/intel_rdt: Resctrl files reflect pseudo-locked information")
Fixes: 443810fe61605 ("x86/intel_rdt: Create debugfs files for pseudo-locking testing")
Fixes: 746e08590b864 ("x86/intel_rdt: Create character device exposing pseudo-locked region")
Fixes: 33dc3e410a0d9 ("x86/intel_rdt: Make CPU information accessible for pseudo-locked regions")
Signed-off-by: Jithu Joseph <jithu.joseph@intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: fenghua.yu@intel.com
Cc: tony.luck@intel.com
Cc: gavin.hindman@intel.com
Cc: hpa@zytor.com
Link: https://lkml.kernel.org/r/231f742dbb7b00a31cc104416860e27dba6b072d.1539384145.git.reinette.chatre@intel.com
Diffstat (limited to 'arch/x86/kernel/cpu/intel_rdt_ctrlmondata.c')
| -rw-r--r-- | arch/x86/kernel/cpu/intel_rdt_ctrlmondata.c | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/arch/x86/kernel/cpu/intel_rdt_ctrlmondata.c b/arch/x86/kernel/cpu/intel_rdt_ctrlmondata.c index 0f53049719cd..27937458c231 100644 --- a/arch/x86/kernel/cpu/intel_rdt_ctrlmondata.c +++ b/arch/x86/kernel/cpu/intel_rdt_ctrlmondata.c @@ -404,8 +404,16 @@ int rdtgroup_schemata_show(struct kernfs_open_file *of, for_each_alloc_enabled_rdt_resource(r) seq_printf(s, "%s:uninitialized\n", r->name); } else if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED) { - seq_printf(s, "%s:%d=%x\n", rdtgrp->plr->r->name, - rdtgrp->plr->d->id, rdtgrp->plr->cbm); + if (!rdtgrp->plr->d) { + rdt_last_cmd_clear(); + rdt_last_cmd_puts("Cache domain offline\n"); + ret = -ENODEV; + } else { + seq_printf(s, "%s:%d=%x\n", + rdtgrp->plr->r->name, + rdtgrp->plr->d->id, + rdtgrp->plr->cbm); + } } else { closid = rdtgrp->closid; for_each_alloc_enabled_rdt_resource(r) { |