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authorFenghua Yu <fenghua.yu@intel.com>2022-02-07 15:02:47 -0800
committerBorislav Petkov <bp@suse.de>2022-02-14 19:51:47 +0100
commita6cbd44093ef305b02ad5f80ed54abf0148a696c (patch)
treea45fd78b4519c5ceb593e751da6e459bd237a693 /include/linux/sched
parent7a5fbc9bcba5325a45297a4ba00091f39a63a1ed (diff)
kernel/fork: Initialize mm's PASID
A new mm doesn't have a PASID yet when it's created. Initialize the mm's PASID on fork() or for init_mm to INVALID_IOASID (-1). INIT_PASID (0) is reserved for kernel legacy DMA PASID. It cannot be allocated to a user process. Initializing the process's PASID to 0 may cause confusion that's why the process uses the reserved kernel legacy DMA PASID. Initializing the PASID to INVALID_IOASID (-1) explicitly tells the process doesn't have a valid PASID yet. Even though the only user of mm_pasid_init() is in fork.c, define it in <linux/sched/mm.h> as the first of three mm/pasid life cycle functions (init/set/drop) to keep these all together. Suggested-by: Dave Hansen <dave.hansen@linux.intel.com> Signed-off-by: Fenghua Yu <fenghua.yu@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Tony Luck <tony.luck@intel.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20220207230254.3342514-5-fenghua.yu@intel.com
Diffstat (limited to 'include/linux/sched')
-rw-r--r--include/linux/sched/mm.h10
1 files changed, 10 insertions, 0 deletions
diff --git a/include/linux/sched/mm.h b/include/linux/sched/mm.h
index aa5f09ca5bcf..c74d1edbac2f 100644
--- a/include/linux/sched/mm.h
+++ b/include/linux/sched/mm.h
@@ -8,6 +8,7 @@
#include <linux/mm_types.h>
#include <linux/gfp.h>
#include <linux/sync_core.h>
+#include <linux/ioasid.h>
/*
* Routines for handling mm_structs
@@ -433,4 +434,13 @@ static inline void membarrier_update_current_mm(struct mm_struct *next_mm)
}
#endif
+#ifdef CONFIG_IOMMU_SVA
+static inline void mm_pasid_init(struct mm_struct *mm)
+{
+ mm->pasid = INVALID_IOASID;
+}
+#else
+static inline void mm_pasid_init(struct mm_struct *mm) {}
+#endif
+
#endif /* _LINUX_SCHED_MM_H */