Commit-ID: a5b162b2ecb013ed517ab5ce90079117ada743f4
Gitweb: https://git.kernel.org/tip/a5b162b2ecb013ed517ab5ce90079117ada743f4
Author: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
AuthorDate: Mon, 5 Mar 2018 11:16:41 +0300
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Mon, 12 Mar 2018 10:30:48 +0100
x86/mm: Do not use paravirtualized calls in native_set_p4d()
In 4-level paging mode, native_set_p4d() updates the entry in the top-level
page table. With PTI, update to the top-level kernel page table requires
update to the userspace copy of the table as well, using pti_set_user_pgd().
native_set_p4d() uses p4d_val() and pgd_val() to convert types between
p4d_t and pgd_t.
p4d_val() and pgd_val() are paravirtualized and we must not use them in
native helpers, as they crash the boot in paravirtualized environments.
Replace p4d_val() and pgd_val() with native_p4d_val() and
native_pgd_val() in native_set_p4d().
Reported-by: Fengguang Wu <fengguang.wu@xxxxxxxxx>
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Brian Gerst <brgerst@xxxxxxxxx>
Cc: Denys Vlasenko <dvlasenk@xxxxxxxxxx>
Cc: H. Peter Anvin <hpa@xxxxxxxxx>
Cc: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Fixes: 91f606a8fa68 ("x86/mm: Replace compile-time checks for 5-level paging with runtime-time checks")
Link: http://lkml.kernel.org/r/20180305081641.4290-1-kirill.shutemov@xxxxxxxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
arch/x86/include/asm/pgtable_64.h | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/x86/include/asm/pgtable_64.h b/arch/x86/include/asm/pgtable_64.h
index 81dda8d1d0bd..163e01a0631d 100644
--- a/arch/x86/include/asm/pgtable_64.h
+++ b/arch/x86/include/asm/pgtable_64.h
@@ -224,9 +224,9 @@ static inline void native_set_p4d(p4d_t *p4dp, p4d_t p4d)
return;
}
- pgd = native_make_pgd(p4d_val(p4d));
+ pgd = native_make_pgd(native_p4d_val(p4d));
pgd = pti_set_user_pgd((pgd_t *)p4dp, pgd);
- *p4dp = native_make_p4d(pgd_val(pgd));
+ *p4dp = native_make_p4d(native_pgd_val(pgd));
}
static inline void native_p4d_clear(p4d_t *p4d)
--
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