Hi Dave,
At 07/11/2018 03:33 AM, Dave Anderson wrote:
The final phase of support would be making this work:
static int
x86_64_task_uses_5level(struct task_context *tc)
{
return FALSE;
}
Have you had a chance to look at how that can be done?
I have no idea to check if 5level paging is used in User-space.
You gave me some methods, and I have try:
-The MAP_FIXED flag
-check if the contents of the page directory or p4d is 'flods'
Now, I found a rough way. As We all know, in x86_64_uvtop_level4(),
the user virtual address is either 4-level or 5-level paging. Can we
do like that:
if (machdep->flags & VM_5LEVEL)
1) Using 5-level parsing code...
2) Check if it is success
If failed, Using 4-level parsing code...
else
Always using 4-level parsing code...
3) go on...
Thanks,
dou
--------------8<----------------
diff --git a/x86_64.c b/x86_64.c
index 07b6aa9..0e12825 100644
--- a/x86_64.c
+++ b/x86_64.c
@@ -1915,22 +1915,21 @@ x86_64_uvtop_level4(struct task_context *tc,
ulong uvaddr, physaddr_t *paddr, in
goto no_upage;
/* If the VM is in 5-level page table */
- if (machdep->flags & VM_5LEVEL && x86_64_task_uses_5level(tc)) {
+ if (machdep->flags & VM_5LEVEL) {
ulong p4d_pte;
/*
* p4d = p4d_offset(pgd, address);
*/
p4d_pte = x86_64_p4d_offset(pgd_pte, uvaddr, verbose,
FALSE);
- if (!(p4d_pte & _PAGE_PRESENT))
- goto no_upage;
- /*
- * pud = pud_offset(p4d, address);
- */
- pud_pte = x86_64_pud_offset(p4d_pte, uvaddr, verbose,
FALSE);
+ if (!(p4d_pte & _PAGE_PRESENT)) {
+ /* pud = pud_offset(pgd, address); */
+ pud_pte = x86_64_pud_offset(pgd_pte, uvaddr,
verbose, FALSE);
+ } else {
+ /* pud = pud_offset(p4d, address); */
+ pud_pte = x86_64_pud_offset(p4d_pte, uvaddr,
verbose, FALSE);
+ }
} else {
- /*
- * pud = pud_offset(pgd, address);
- */
+ /* pud = pud_offset(pgd, address); */
pud_pte = x86_64_pud_offset(pgd_pte, uvaddr, verbose,
FALSE);
}
--
Crash-utility mailing list
Crash-utility@xxxxxxxxxx
https://www.redhat.com/mailman/listinfo/crash-utility
