Messages in this thread Patch in this message | | | Subject | Re: [PATCH 4.4 41/43] x86/mm/pat: Make set_memory_np() L1TF safe | From | Guenter Roeck <> | Date | Sun, 9 Sep 2018 10:06:06 -0700 |
| |
On 09/09/2018 09:46 AM, Ben Hutchings wrote: > On Tue, 2018-08-14 at 19:18 +0200, Greg Kroah-Hartman wrote: >> 4.4-stable review patch. If anyone has any objections, please let me know. >> >> ------------------ >> >> From: Andi Kleen <ak@linux.intel.com> >> >> commit 958f79b9ee55dfaf00c8106ed1c22a2919e0028b upstream > [...] >> --- a/arch/x86/include/asm/pgtable.h >> +++ b/arch/x86/include/asm/pgtable.h >> @@ -378,12 +378,39 @@ static inline pmd_t pfn_pmd(unsigned lon >>> return __pmd(pfn | massage_pgprot(pgprot)); >> } >> >> +static inline pud_t pfn_pud(unsigned long page_nr, pgprot_t pgprot) >> +{ >> + phys_addr_t pfn = page_nr << PAGE_SHIFT; >> + pfn ^= protnone_mask(pgprot_val(pgprot)); >> + pfn &= PHYSICAL_PUD_PAGE_MASK; >> + return __pud(pfn | massage_pgprot(pgprot)); >> +} > [...] > > This (and the backport to 4.9) are missing the fix from commit > e14d7dfb41f5 "x86/speculation/l1tf: Fix up pte->pfn conversion for > PAE", as that was applied earlier in the series. But since PAE implies > only 3-level paging I don't know how the PUD functions get used or > whether this actually matters. > Excellent find.
e14d7dfb41f5 (re-)applies cleanly to both 4.4.y and 4.9.y. Since most of its changes are already applied, the only remaining change is
diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h index c535012bdb56..5736306bdaab 100644 --- a/arch/x86/include/asm/pgtable.h +++ b/arch/x86/include/asm/pgtable.h @@ -420,7 +420,7 @@ static inline pmd_t pfn_pmd(unsigned long page_nr, pgprot_t pgprot)
static inline pud_t pfn_pud(unsigned long page_nr, pgprot_t pgprot) { - phys_addr_t pfn = page_nr << PAGE_SHIFT; + phys_addr_t pfn = (phys_addr_t)page_nr << PAGE_SHIFT; pfn ^= protnone_mask(pgprot_val(pgprot)); pfn &= PHYSICAL_PUD_PAGE_MASK; return __pud(pfn | massage_pgprot(pgprot)); after cherry-picking it into both branches.
I think we should re-apply it to both 4.4.y and 4.9.y be on the safe side.
Thanks, Guenter
| |