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| author |   Thomas Gleixner <tglx@linutronix.de> | 2019-04-15 10:46:07 +0200 |
|---|---|---|
| committer |   Ingo Molnar <mingo@kernel.org> | 2019-04-16 09:42:10 +0200 |
| commit | 510bb96fe5b3480b4b22d815786377e54cb701e7 (patch) | |
| tree | afdfca77448b5acac50a2fcfba1c2d2d77d6c73b /arch/x86 | |
| parent | x86/build/lto: Fix truncated .bss with -fdata-sections (diff) | |
| download | linux-dev-510bb96fe5b3480b4b22d815786377e54cb701e7.tar.xz linux-dev-510bb96fe5b3480b4b22d815786377e54cb701e7.zip | |
x86/mm: Prevent bogus warnings with "noexec=off"
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 <xose.vazquez@gmail.com>
Tested-by: Xose Vazquez Perez <xose.vazquez@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@surriel.com>
Link: http://lkml.kernel.org/r/alpine.DEB.2.21.1904151037530.1729@nanos.tec.linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/mm/dump_pagetables.c | 3 | ||||
| -rw-r--r-- | 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 ee8f8ab46941..c0309ea9abee 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 0029604af8a4..dd73d5d74393 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)); |