x86/mm/pti: Populate user PGD
authorDave Hansen <dave.hansen@linux.intel.com>
Mon, 4 Dec 2017 14:07:40 +0000 (15:07 +0100)
committerIngo Molnar <mingo@kernel.org>
Sat, 23 Dec 2017 20:13:00 +0000 (21:13 +0100)
In clone_pgd_range() copy the init user PGDs which cover the kernel half of
the address space, so a process has all the required kernel mappings

[ tglx: Split out from the big kaiser dump and folded Andys simplification ]

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

index 2d2d073..cc6fa75 100644 (file)
@@ -1119,7 +1119,14 @@ static inline void pmdp_set_wrprotect(struct mm_struct *mm,
 static inline void clone_pgd_range(pgd_t *dst, pgd_t *src, int count)
-       memcpy(dst, src, count * sizeof(pgd_t));
+       memcpy(dst, src, count * sizeof(pgd_t));
+       if (!static_cpu_has(X86_FEATURE_PTI))
+               return;
+       /* Clone the user space pgd as well */
+       memcpy(kernel_to_user_pgdp(dst), kernel_to_user_pgdp(src),
+              count * sizeof(pgd_t));
 #define PTE_SHIFT ilog2(PTRS_PER_PTE)