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| 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 | |
| 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
| -rw-r--r-- | include/linux/sched/mm.h | 10 | ||||
| -rw-r--r-- | kernel/fork.c | 10 | ||||
| -rw-r--r-- | mm/init-mm.c | 4 |
3 files changed, 16 insertions, 8 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 */ diff --git a/kernel/fork.c b/kernel/fork.c index 6ee7551d3bd2..deacd2c17a7f 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -97,6 +97,7 @@ #include <linux/scs.h> #include <linux/io_uring.h> #include <linux/bpf.h> +#include <linux/sched/mm.h> #include <asm/pgalloc.h> #include <linux/uaccess.h> @@ -1019,13 +1020,6 @@ static void mm_init_owner(struct mm_struct *mm, struct task_struct *p) #endif } -static void mm_init_pasid(struct mm_struct *mm) -{ -#ifdef CONFIG_IOMMU_SVA - mm->pasid = INIT_PASID; -#endif -} - static void mm_init_uprobes_state(struct mm_struct *mm) { #ifdef CONFIG_UPROBES @@ -1054,7 +1048,7 @@ static struct mm_struct *mm_init(struct mm_struct *mm, struct task_struct *p, mm_init_cpumask(mm); mm_init_aio(mm); mm_init_owner(mm, p); - mm_init_pasid(mm); + mm_pasid_init(mm); RCU_INIT_POINTER(mm->exe_file, NULL); mmu_notifier_subscriptions_init(mm); init_tlb_flush_pending(mm); 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) }; |