git: 34516d4ad19b - main - amd64 pti init: fix calculation of the kernel text start

[Konstantin Belousov]

The branch main has been updated by kib:

URL: https://cgit.FreeBSD.org/src/commit/?id=34516d4ad19b83e5dfe6ec8c1db232c422d7ecff

commit 34516d4ad19b83e5dfe6ec8c1db232c422d7ecff
Author:     Konstantin Belousov <kib at FreeBSD.org>
AuthorDate: 2021-07-10 19:51:16 +0000
Commit:     Konstantin Belousov <kib at FreeBSD.org>
CommitDate: 2021-07-24 15:52:44 +0000

    amd64 pti init: fix calculation of the kernel text start
    
    Old expression happens to provide the correct answer, but assumes that
    kernel is loaded at physical address zero, with 2M gap.  Do not use
    kernphys to calculate KVA of kernel text start, just explicitly write
    out KERNBASE and the hole size.
    
    Reviewed by:    markj
    Sponsored by:   The FreeBSD Foundation
    MFC after:      1 week
    Differential revision:  https://reviews.freebsd.org/D31121
---
 sys/amd64/amd64/pmap.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/sys/amd64/amd64/pmap.c b/sys/amd64/amd64/pmap.c
index 688412594e6c..03436a60a10b 100644
--- a/sys/amd64/amd64/pmap.c
+++ b/sys/amd64/amd64/pmap.c
@@ -10762,7 +10762,7 @@ pmap_pti_init(void)
 		va = __pcpu[i].pc_common_tss.tss_ist4 + sizeof(struct nmi_pcpu);
 		pmap_pti_add_kva_locked(va - DBG_STACK_SIZE, va, false);
 	}
-	pmap_pti_add_kva_locked((vm_offset_t)kernphys + KERNBASE,
+	pmap_pti_add_kva_locked((vm_offset_t)KERNBASE + NBPDR,
 	    (vm_offset_t)etext, true);
 	pti_finalized = true;
 	VM_OBJECT_WUNLOCK(pti_obj);