From: Thomas Gleixner <[email protected]>
[ Upstream commit 510bb96fe5b3480b4b22d815786377e54cb701e7 ]
Xose Vazquez Perez reported boot warnings when NX is disabled on the kernel
command line.
__early_set_fixmap() triggers this warning:
attempted to set unsupported pgprot: 8000000000000163
bits: 8000000000000000
supported: 7fffffffffffffff
WARNING: CPU: 0 PID: 0 at arch/x86/include/asm/pgtable.h:537
__early_set_fixmap+0xa2/0xff
because it uses __default_kernel_pte_mask to mask out unsupported bits.
Use __supported_pte_mask instead.
Disabling NX on the command line also triggers the NX warning in the page
table mapping check:
WARNING: CPU: 1 PID: 1 at arch/x86/mm/dump_pagetables.c:262
note_page+0x2ae/0x650
....
Make the warning depend on NX set in __supported_pte_mask.
Reported-by: Xose Vazquez Perez <[email protected]>
Tested-by: Xose Vazquez Perez <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Cc: Andy Lutomirski <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: H. Peter Anvin <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Rik van Riel <[email protected]>
Link:
http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
---
arch/x86/mm/dump_pagetables.c | 3 ++-
arch/x86/mm/ioremap.c | 2 +-
2 files changed, 3 insertions(+), 2 deletions(-)
diff --git a/arch/x86/mm/dump_pagetables.c b/arch/x86/mm/dump_pagetables.c
index e3cdc85ce5b6..84304626b1cb 100644
--- a/arch/x86/mm/dump_pagetables.c
+++ b/arch/x86/mm/dump_pagetables.c
@@ -259,7 +259,8 @@ static void note_wx(struct pg_state *st)
#endif
/* Account the WX pages */
st->wx_pages += npages;
- WARN_ONCE(1, "x86/mm: Found insecure W+X mapping at address %pS\n",
+ WARN_ONCE(__supported_pte_mask & _PAGE_NX,
+ "x86/mm: Found insecure W+X mapping at address %pS\n",
(void *)st->start_address);
}
diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c
index 5378d10f1d31..3b76fe954978 100644
--- a/arch/x86/mm/ioremap.c
+++ b/arch/x86/mm/ioremap.c
@@ -825,7 +825,7 @@ void __init __early_set_fixmap(enum fixed_addresses idx,
pte = early_ioremap_pte(addr);
/* Sanitize 'prot' against any unsupported bits: */
- pgprot_val(flags) &= __default_kernel_pte_mask;
+ pgprot_val(flags) &= __supported_pte_mask;
if (pgprot_val(flags))
set_pte(pte, pfn_pte(phys >> PAGE_SHIFT, flags));
--
2.20.1
