Module Name: src
Committed By: thorpej
Date: Sat Dec 30 23:07:42 UTC 2023
Modified Files:
src/sys/arch/alpha/alpha: pmap.c
Log Message:
pmap_bootstrap(): When initializing the L2 PTEs, don't use l2pte_index(),
as it is designed to wrap from 1023->0 during the normal course of use.
However, when setting up the initial kernel page tables, if we have a
large enough config that we end up with more than L2 PT page, we rely
on being able to index > 1023 into the adjacent PT pages to initialize
those entries.
Fixes a MM fault panic during early boot on larger memory configs
(reported by Dave McGuire with an 8GB ES40 and John Klos with a 12GB
DS25). I've successfully booted at 16GB config in Qemu with this fix.
To generate a diff of this commit:
cvs rdiff -u -r1.307 -r1.308 src/sys/arch/alpha/alpha/pmap.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/arch/alpha/alpha/pmap.c
diff -u src/sys/arch/alpha/alpha/pmap.c:1.307 src/sys/arch/alpha/alpha/pmap.c:1.308
--- src/sys/arch/alpha/alpha/pmap.c:1.307 Sat Apr 9 23:38:31 2022
+++ src/sys/arch/alpha/alpha/pmap.c Sat Dec 30 23:07:42 2023
@@ -1,4 +1,4 @@
-/* $NetBSD: pmap.c,v 1.307 2022/04/09 23:38:31 riastradh Exp $ */
+/* $NetBSD: pmap.c,v 1.308 2023/12/30 23:07:42 thorpej Exp $ */
/*-
* Copyright (c) 1998, 1999, 2000, 2001, 2007, 2008, 2020
@@ -135,7 +135,7 @@
#include <sys/cdefs.h> /* RCS ID & Copyright macro defns */
-__KERNEL_RCSID(0, "$NetBSD: pmap.c,v 1.307 2022/04/09 23:38:31 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: pmap.c,v 1.308 2023/12/30 23:07:42 thorpej Exp $");
#include <sys/param.h>
#include <sys/systm.h>
@@ -1204,13 +1204,15 @@ static bool vtophys_internal(vaddr_t, pa
l1pte_ = pmap_l1pte(kernel_lev1map, va); \
if (pmap_pte_v(l1pte_) == 0) { \
printf("kernel level 1 PTE not valid, va 0x%lx " \
- "(line %d)\n", (va), __LINE__); \
+ "(line %d) pte=%p *pte=0x%016lx\n", (va), __LINE__, \
+ l1pte_, *l1pte_); \
panic("PMAP_KERNEL_PTE"); \
} \
l2pte_ = pmap_l2pte(kernel_lev1map, va, l1pte_); \
if (pmap_pte_v(l2pte_) == 0) { \
printf("kernel level 2 PTE not valid, va 0x%lx " \
- "(line %d)\n", (va), __LINE__); \
+ "(line %d) pte=%p *pte=0x%016lx\n", (va), __LINE__, \
+ l2pte_, *l2pte_); \
panic("PMAP_KERNEL_PTE"); \
} \
pmap_l3pte(kernel_lev1map, va, l2pte_); \
@@ -1358,8 +1360,19 @@ pmap_bootstrap(paddr_t ptaddr, u_int max
pte = (ALPHA_K0SEG_TO_PHYS(((vaddr_t)lev3map) +
(i*PAGE_SIZE)) >> PGSHIFT) << PG_SHIFT;
pte |= PG_V | PG_ASM | PG_KRE | PG_KWE | PG_WIRED;
- lev2map[l2pte_index(VM_MIN_KERNEL_ADDRESS+
- (i*PAGE_SIZE*NPTEPG))] = pte;
+ /*
+ * No need to use l2pte_index() here; it's equivalent
+ * to just indexing with our loop variable i, but will
+ * fall over if we end up with more than 1 L2 PT page.
+ *
+ * In other words:
+ *
+ * l2pte_index(VM_MIN_KERNEL_ADDRESS +
+ * (i*PAGE_SIZE*NPTEPG))
+ *
+ * ...is the same as 'i' so long as i stays below 1024.
+ */
+ lev2map[i] = pte;
}
/* Initialize the pmap_growkernel_lock. */
