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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.c | |
| parent | 2a7adf6ce643fdeec051dc88e5250b08c83bbb67 (diff) | |
| download | linux-b61b8bba18fe2b63d38fdaf9b83de25e2d787dfe.tar.gz linux-b61b8bba18fe2b63d38fdaf9b83de25e2d787dfe.tar.bz2 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.c')
| -rw-r--r-- | arch/x86/kernel/cpu/intel_rdt.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/arch/x86/kernel/cpu/intel_rdt.c b/arch/x86/kernel/cpu/intel_rdt.c index 1214f3f7ec6d..44272b7107ad 100644 --- a/arch/x86/kernel/cpu/intel_rdt.c +++ b/arch/x86/kernel/cpu/intel_rdt.c @@ -608,6 +608,13 @@ static void domain_remove_cpu(int cpu, struct rdt_resource *r) cancel_delayed_work(&d->cqm_limbo); } + /* + * rdt_domain "d" is going to be freed below, so clear + * its pointer from pseudo_lock_region struct. + */ + if (d->plr) + d->plr->d = NULL; + kfree(d->ctrl_val); kfree(d->mbps_val); bitmap_free(d->rmid_busy_llc); |