diff options
| author | Fenghua Yu <fenghua.yu@intel.com> | 2022-02-08 00:02:47 +0100 |
|---|---|---|
| committer | Borislav Petkov <bp@suse.de> | 2022-02-14 19:51:47 +0100 |
| commit | a6cbd44093ef305b02ad5f80ed54abf0148a696c (patch) | |
| tree | a45fd78b4519c5ceb593e751da6e459bd237a693 /mm/init-mm.c | |
| parent | iommu/ioasid: Introduce a helper to check for valid PASIDs (diff) | |
| download | linux-a6cbd44093ef305b02ad5f80ed54abf0148a696c.tar.xz linux-a6cbd44093ef305b02ad5f80ed54abf0148a696c.zip | |
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.c | 4 |
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) }; |