From: Xiaochen Shen xiaochen.shen@intel.com
[ Upstream commit c8eafe1495303bfd0eedaa8156b1ee9082ee9642 ]
rdtgroup_cpus_write() and mkdir_rdt_prepare() call rdtgroup_kn_lock_live() -> kernfs_to_rdtgroup() to get 'rdtgrp', and then call the rdt_last_cmd_{clear,puts,...}() functions which will check if rdtgroup_mutex is held/requires its caller to hold rdtgroup_mutex.
But if 'rdtgrp' returned from kernfs_to_rdtgroup() is NULL, rdtgroup_mutex is not held and calling rdt_last_cmd_{clear,puts,...}() will result in a self-incurred, potential lockdep warning.
Remove the rdt_last_cmd_{clear,puts,...}() calls in these two paths. Just returning error should be sufficient to report to the user that the entry doesn't exist any more.
[ bp: Massage. ]
Fixes: 94457b36e8a5 ("x86/intel_rdt: Add diagnostics when writing the cpus file") Fixes: cfd0f34e4cd5 ("x86/intel_rdt: Add diagnostics when making directories") Signed-off-by: Xiaochen Shen xiaochen.shen@intel.com Signed-off-by: Borislav Petkov bp@suse.de Reviewed-by: Tony Luck tony.luck@intel.com Reviewed-by: Fenghua Yu fenghua.yu@intel.com Reviewed-by: Reinette Chatre reinette.chatre@intel.com Cc: "H. Peter Anvin" hpa@zytor.com Cc: Ingo Molnar mingo@redhat.com Cc: pei.p.jia@intel.com Cc: Thomas Gleixner tglx@linutronix.de Cc: x86-ml x86@kernel.org Link: https://lkml.kernel.org/r/1573079796-11713-1-git-send-email-xiaochen.shen@in... Signed-off-by: Sasha Levin sashal@kernel.org --- arch/x86/kernel/cpu/resctrl/rdtgroup.c | 4 ---- 1 file changed, 4 deletions(-)
diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c index a46dee8e78db4..2e3b06d6bbc6d 100644 --- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c +++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c @@ -461,10 +461,8 @@ static ssize_t rdtgroup_cpus_write(struct kernfs_open_file *of, }
rdtgrp = rdtgroup_kn_lock_live(of->kn); - rdt_last_cmd_clear(); if (!rdtgrp) { ret = -ENOENT; - rdt_last_cmd_puts("Directory was removed\n"); goto unlock; }
@@ -2648,10 +2646,8 @@ static int mkdir_rdt_prepare(struct kernfs_node *parent_kn, int ret;
prdtgrp = rdtgroup_kn_lock_live(prgrp_kn); - rdt_last_cmd_clear(); if (!prdtgrp) { ret = -ENODEV; - rdt_last_cmd_puts("Directory was removed\n"); goto out_unlock; }