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author | Dave Hansen <dave.hansen@linux.intel.com> | 2018-04-06 13:55:09 -0700 |
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committer | Ingo Molnar <mingo@kernel.org> | 2018-04-12 09:04:22 +0200 |
commit | fb43d6cb91ef57d9e58d5f69b423784ff4a4c374 (patch) | |
tree | 4785de6f0a6b6b3bf0ef8df64c400af3c34cdfbc /arch/x86/boot | |
parent | 6baf4bec02dbc41645c3a5130ee15a8e1d62b80f (diff) | |
download | linux-fb43d6cb91ef57d9e58d5f69b423784ff4a4c374.tar.bz2 |
x86/mm: Do not auto-massage page protections
A PTE is constructed from a physical address and a pgprotval_t.
__PAGE_KERNEL, for instance, is a pgprot_t and must be converted
into a pgprotval_t before it can be used to create a PTE. This is
done implicitly within functions like pfn_pte() by massage_pgprot().
However, this makes it very challenging to set bits (and keep them
set) if your bit is being filtered out by massage_pgprot().
This moves the bit filtering out of pfn_pte() and friends. For
users of PAGE_KERNEL*, filtering will be done automatically inside
those macros but for users of __PAGE_KERNEL*, they need to do their
own filtering now.
Note that we also just move pfn_pte/pmd/pud() over to check_pgprot()
instead of massage_pgprot(). This way, we still *look* for
unsupported bits and properly warn about them if we find them. This
might happen if an unfiltered __PAGE_KERNEL* value was passed in,
for instance.
- printk format warning fix from: Arnd Bergmann <arnd@arndb.de>
- boot crash fix from: Tom Lendacky <thomas.lendacky@amd.com>
- crash bisected by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reported-and-fixed-by: Arnd Bergmann <arnd@arndb.de>
Fixed-by: Tom Lendacky <thomas.lendacky@amd.com>
Bisected-by: Mike Galbraith <efault@gmx.de>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Kees Cook <keescook@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Nadav Amit <namit@vmware.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/20180406205509.77E1D7F6@viggo.jf.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/boot')
-rw-r--r-- | arch/x86/boot/compressed/kaslr.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/x86/boot/compressed/kaslr.c b/arch/x86/boot/compressed/kaslr.c index 66e42a098d70..a0a50b91ecef 100644 --- a/arch/x86/boot/compressed/kaslr.c +++ b/arch/x86/boot/compressed/kaslr.c @@ -54,6 +54,9 @@ unsigned int ptrs_per_p4d __ro_after_init = 1; extern unsigned long get_cmd_line_ptr(void); +/* Used by PAGE_KERN* macros: */ +pteval_t __default_kernel_pte_mask __read_mostly = ~0; + /* Simplified build-specific string for starting entropy. */ static const char build_str[] = UTS_RELEASE " (" LINUX_COMPILE_BY "@" LINUX_COMPILE_HOST ") (" LINUX_COMPILER ") " UTS_VERSION; |