svn commit: r339774 - head/sys/riscv/riscv
Ruslan Bukin
br at FreeBSD.org
Fri Oct 26 12:27:08 UTC 2018
Author: br
Date: Fri Oct 26 12:27:07 2018
New Revision: 339774
URL: https://svnweb.freebsd.org/changeset/base/339774
Log:
o Add pmap lock around pmap_fault_fixup() to ensure other thread will not
modify l3 pte after we loaded old value and before we stored new value.
o Preset A(accessed), D(dirty) bits for kernel mappings.
Reported by: kib
Reviewed by: markj
Discussed with: jhb
Sponsored by: DARPA, AFRL
Modified:
head/sys/riscv/riscv/pmap.c
Modified: head/sys/riscv/riscv/pmap.c
==============================================================================
--- head/sys/riscv/riscv/pmap.c Fri Oct 26 11:53:20 2018 (r339773)
+++ head/sys/riscv/riscv/pmap.c Fri Oct 26 12:27:07 2018 (r339774)
@@ -2015,16 +2015,21 @@ pmap_fault_fixup(pmap_t pmap, vm_offset_t va, vm_prot_
pt_entry_t orig_l3;
pt_entry_t new_l3;
pt_entry_t *l3;
+ int rv;
+ rv = 0;
+
+ PMAP_LOCK(pmap);
+
l3 = pmap_l3(pmap, va);
if (l3 == NULL)
- return (0);
+ goto done;
orig_l3 = pmap_load(l3);
if ((orig_l3 & PTE_V) == 0 ||
((prot & VM_PROT_WRITE) != 0 && (orig_l3 & PTE_W) == 0) ||
((prot & VM_PROT_READ) != 0 && (orig_l3 & PTE_R) == 0))
- return (0);
+ goto done;
new_l3 = orig_l3 | PTE_A;
if ((prot & VM_PROT_WRITE) != 0)
@@ -2033,7 +2038,8 @@ pmap_fault_fixup(pmap_t pmap, vm_offset_t va, vm_prot_
if (orig_l3 != new_l3) {
pmap_load_store(l3, new_l3);
pmap_invalidate_page(pmap, va);
- return (1);
+ rv = 1;
+ goto done;
}
/*
@@ -2041,7 +2047,10 @@ pmap_fault_fixup(pmap_t pmap, vm_offset_t va, vm_prot_
* the PTE shouldn't have resulted in a fault.
*/
- return (0);
+done:
+ PMAP_UNLOCK(pmap);
+
+ return (rv);
}
/*
@@ -2084,6 +2093,8 @@ pmap_enter(pmap_t pmap, vm_offset_t va, vm_page_t m, v
new_l3 |= PTE_W;
if ((va >> 63) == 0)
new_l3 |= PTE_U;
+ else
+ new_l3 |= PTE_A | PTE_D;
new_l3 |= (pn << PTE_PPN0_S);
if ((flags & PMAP_ENTER_WIRED) != 0)
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