diff options
| author | Fenghua Yu <[email protected]> | 2016-12-01 12:55:14 -0800 |
|---|---|---|
| committer | Thomas Gleixner <[email protected]> | 2016-12-02 01:13:02 +0100 |
| commit | 74fcdae1a7fdf30de5413ccc1eca271415d01124 (patch) | |
| tree | a742dd6c925c16c6fda8d3c34393b4ec19db8db7 | |
| parent | 0efc89be9471b152599d2db7eb47de8e0d71c59f (diff) | |
x86/intel_rdt: Call intel_rdt_sched_in() with preemption disabled
intel_rdt_sched_in() must be called with preemption disabled because the
function accesses percpu variables (pqr_state and closid).
If a task moves itself via move_myself() preemption is enabled, which
violates the calling convention and can result in incorrect closid
selection when the task gets preempted or migrated.
Add the required protection and a comment about the calling convention.
Signed-off-by: Fenghua Yu <[email protected]>
Cc: "Ravi V Shankar" <[email protected]>
Cc: "Tony Luck" <[email protected]>
Cc: "Marcelo Tosatti" <[email protected]>
Cc: "Sai Prakhya" <[email protected]>
Cc: "Vikas Shivappa" <[email protected]>
Cc: "H. Peter Anvin" <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Thomas Gleixner <[email protected]>
| -rw-r--r-- | arch/x86/include/asm/intel_rdt.h | 2 | ||||
| -rw-r--r-- | arch/x86/kernel/cpu/intel_rdt_rdtgroup.c | 2 |
2 files changed, 4 insertions, 0 deletions
diff --git a/arch/x86/include/asm/intel_rdt.h b/arch/x86/include/asm/intel_rdt.h index 6e90e87eadfe..95ce5c85b009 100644 --- a/arch/x86/include/asm/intel_rdt.h +++ b/arch/x86/include/asm/intel_rdt.h @@ -192,6 +192,8 @@ int rdtgroup_schemata_show(struct kernfs_open_file *of, * resctrl file system. * - Caches the per cpu CLOSid values and does the MSR write only * when a task with a different CLOSid is scheduled in. + * + * Must be called with preemption disabled. */ static inline void intel_rdt_sched_in(void) { diff --git a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c index fb8e03e2b70d..1afd3f393501 100644 --- a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c +++ b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c @@ -326,8 +326,10 @@ static void move_myself(struct callback_head *head) kfree(rdtgrp); } + preempt_disable(); /* update PQR_ASSOC MSR to make resource group go into effect */ intel_rdt_sched_in(); + preempt_enable(); kfree(callback); } |