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authorLinus Torvalds <torvalds@linux-foundation.org>2022-03-21 22:28:13 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2022-03-21 22:28:13 +0300
commit3fd33273a4675e819544ccbbf8d769e14672666b (patch)
treede1dc2f55a4d6f6445ac622eb67ed89103574403 /kernel/fork.c
parenteaa54b1458ca84092e513d554dd6d234245e6bef (diff)
parent83aa52ffed5d35a08e24452d0471e1684075cdf8 (diff)
downloadlinux-3fd33273a4675e819544ccbbf8d769e14672666b.tar.xz
Merge tag 'x86-pasid-2022-03-21' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 PASID support from Thomas Gleixner: "Reenable ENQCMD/PASID support: - Simplify the PASID handling to allocate the PASID once, associate it to the mm of a process and free it on mm_exit(). The previous attempt of refcounted PASIDs and dynamic alloc()/free() turned out to be error prone and too complex. The PASID space is 20bits, so the case of resource exhaustion is a pure academic concern. - Populate the PASID MSR on demand via #GP to avoid racy updates via IPIs. - Reenable ENQCMD and let objtool check for the forbidden usage of ENQCMD in the kernel. - Update the documentation for Shared Virtual Addressing accordingly" * tag 'x86-pasid-2022-03-21' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: Documentation/x86: Update documentation for SVA (Shared Virtual Addressing) tools/objtool: Check for use of the ENQCMD instruction in the kernel x86/cpufeatures: Re-enable ENQCMD x86/traps: Demand-populate PASID MSR via #GP sched: Define and initialize a flag to identify valid PASID in the task x86/fpu: Clear PASID when copying fpstate iommu/sva: Assign a PASID to mm on PASID allocation and free it on mm exit kernel/fork: Initialize mm's PASID iommu/ioasid: Introduce a helper to check for valid PASIDs mm: Change CONFIG option for mm->pasid field iommu/sva: Rename CONFIG_IOMMU_SVA_LIB to CONFIG_IOMMU_SVA
Diffstat (limited to 'kernel/fork.c')
-rw-r--r--kernel/fork.c15
1 files changed, 7 insertions, 8 deletions
diff --git a/kernel/fork.c b/kernel/fork.c
index f1e89007f228..b441a81f5fa9 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>
@@ -967,6 +968,10 @@ static struct task_struct *dup_task_struct(struct task_struct *orig, int node)
tsk->use_memdelay = 0;
#endif
+#ifdef CONFIG_IOMMU_SVA
+ tsk->pasid_activated = 0;
+#endif
+
#ifdef CONFIG_MEMCG
tsk->active_memcg = NULL;
#endif
@@ -1019,13 +1024,6 @@ 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_SUPPORT
- mm->pasid = INIT_PASID;
-#endif
-}
-
static void mm_init_uprobes_state(struct mm_struct *mm)
{
#ifdef CONFIG_UPROBES
@@ -1054,7 +1052,7 @@ 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);
@@ -1121,6 +1119,7 @@ static inline void __mmput(struct mm_struct *mm)
}
if (mm->binfmt)
module_put(mm->binfmt->module);
+ mm_pasid_drop(mm);
mmdrop(mm);
}