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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 /mm/init-mm.c
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 'mm/init-mm.c')
-rw-r--r--mm/init-mm.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/mm/init-mm.c b/mm/init-mm.c
index b4a6f38fb51d..fbe7844d0912 100644
--- a/mm/init-mm.c
+++ b/mm/init-mm.c
@@ -10,6 +10,7 @@
#include <linux/atomic.h>
#include <linux/user_namespace.h>
+#include <linux/ioasid.h>
#include <asm/mmu.h>
#ifndef INIT_MM_CONTEXT
@@ -38,6 +39,9 @@ struct mm_struct init_mm = {
.mmlist = LIST_HEAD_INIT(init_mm.mmlist),
.user_ns = &init_user_ns,
.cpu_bitmap = CPU_BITS_NONE,
+#ifdef CONFIG_IOMMU_SVA
+ .pasid = INVALID_IOASID,
+#endif
INIT_MM_CONTEXT(init_mm)
};