BMC/Intel-BMC/linux.git/arch/x86/kernel/ldt.c, branch dev-5.2

x86: Convert some slow-path static_cpu_has() callers to boot_cpu_has()

2019-04-08T10:13:34+00:00

Using static_cpu_has() is pointless on those paths, convert them to the boot_cpu_has() variant. No functional changes. Reported-by: Nadav Amit Signed-off-by: Borislav Petkov Reviewed-by: Rik van Riel Reviewed-by: Juergen Gross # for paravirt Cc: Aubrey Li Cc: Dave Hansen Cc: Dominik Brodowski Cc: "H. Peter Anvin" Cc: Ingo Molnar Cc: Jann Horn Cc: Joerg Roedel Cc: "Kirill A. Shutemov" Cc: Konrad Rzeszutek Wilk Cc: Thomas Lendacky Cc: linux-edac@vger.kernel.org Cc: Masami Hiramatsu Cc: Peter Zijlstra Cc: "Rafael J. Wysocki" Cc: Sebastian Andrzej Siewior Cc: Thomas Gleixner Cc: Tony Luck Cc: virtualization@lists.linux-foundation.org Cc: x86@kernel.org Link: https://lkml.kernel.org/r/20190330112022.28888-3-bp@alien8.de

x86/ldt: Remove unused variable in map_ldt_struct()

2018-11-06T20:35:11+00:00

Splitting out the sanity check in map_ldt_struct() moved page table syncing into a separate function, which made the pgd variable unused. Remove it. [ tglx: Massaged changelog ] Fixes: 9bae3197e15d ("x86/ldt: Split out sanity check in map_ldt_struct()") Signed-off-by: Kirill A. Shutemov Signed-off-by: Thomas Gleixner Reviewed-by: Andy Lutomirski Cc: bp@alien8.de Cc: hpa@zytor.com Cc: dave.hansen@linux.intel.com Cc: peterz@infradead.org Cc: boris.ostrovsky@oracle.com Cc: jgross@suse.com Cc: bhe@redhat.com Cc: willy@infradead.org Cc: linux-mm@kvack.org Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20181026122856.66224-4-kirill.shutemov@linux.intel.com

x86/ldt: Unmap PTEs for the slot before freeing LDT pages

2018-11-06T20:35:11+00:00

modify_ldt(2) leaves the old LDT mapped after switching over to the new one. The old LDT gets freed and the pages can be re-used. Leaving the mapping in place can have security implications. The mapping is present in the userspace page tables and Meltdown-like attacks can read these freed and possibly reused pages. It's relatively simple to fix: unmap the old LDT and flush TLB before freeing the old LDT memory. This further allows to avoid flushing the TLB in map_ldt_struct() as the slot is unmapped and flushed by unmap_ldt_struct() or has never been mapped at all. [ tglx: Massaged changelog and removed the needless line breaks ] Fixes: f55f0501cbf6 ("x86/pti: Put the LDT in its own PGD if PTI is on") Signed-off-by: Kirill A. Shutemov Signed-off-by: Thomas Gleixner Cc: bp@alien8.de Cc: hpa@zytor.com Cc: dave.hansen@linux.intel.com Cc: luto@kernel.org Cc: peterz@infradead.org Cc: boris.ostrovsky@oracle.com Cc: jgross@suse.com Cc: bhe@redhat.com Cc: willy@infradead.org Cc: linux-mm@kvack.org Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20181026122856.66224-3-kirill.shutemov@linux.intel.com

x86/mm/tlb: Add freed_tables argument to flush_tlb_mm_range

2018-10-09T14:51:12+00:00

Add an argument to flush_tlb_mm_range to indicate whether page tables are about to be freed after this TLB flush. This allows for an optimization of flush_tlb_mm_range to skip CPUs in lazy TLB mode. No functional changes. Cc: npiggin@gmail.com Cc: mingo@kernel.org Cc: will.deacon@arm.com Cc: songliubraving@fb.com Cc: kernel-team@fb.com Cc: luto@kernel.org Cc: hpa@zytor.com Signed-off-by: Rik van Riel Signed-off-by: Peter Zijlstra (Intel) Link: http://lkml.kernel.org/r/20180926035844.1420-6-riel@surriel.com

x86/mm: Page size aware flush_tlb_mm_range()

2018-10-09T14:51:11+00:00

Use the new tlb_get_unmap_shift() to determine the stride of the INVLPG loop. Cc: Nick Piggin Cc: Will Deacon Cc: "Aneesh Kumar K.V" Cc: Andrew Morton Cc: Dave Hansen Signed-off-by: Peter Zijlstra (Intel)

x86/ldt: Enable LDT user-mapping for PAE

2018-07-19T23:11:48+00:00

This adds the needed special case for PAE to get the LDT mapped into the user page-table when PTI is enabled. The big difference to the other paging modes is that on PAE there is no full top-level PGD entry available for the LDT, but only a PMD entry. Signed-off-by: Joerg Roedel Signed-off-by: Thomas Gleixner Tested-by: Pavel Machek Cc: "H . Peter Anvin" Cc: linux-mm@kvack.org Cc: Linus Torvalds Cc: Andy Lutomirski Cc: Dave Hansen Cc: Josh Poimboeuf Cc: Juergen Gross Cc: Peter Zijlstra Cc: Borislav Petkov Cc: Jiri Kosina Cc: Boris Ostrovsky Cc: Brian Gerst Cc: David Laight Cc: Denys Vlasenko Cc: Eduardo Valentin Cc: Greg KH Cc: Will Deacon Cc: aliguori@amazon.com Cc: daniel.gruss@iaik.tugraz.at Cc: hughd@google.com Cc: keescook@google.com Cc: Andrea Arcangeli Cc: Waiman Long Cc: "David H . Gutteridge" Cc: joro@8bytes.org Link: https://lkml.kernel.org/r/1531906876-13451-37-git-send-email-joro@8bytes.org

x86/ldt: Split out sanity check in map_ldt_struct()

2018-07-19T23:11:47+00:00

This splits out the mapping sanity check and the actual mapping of the LDT to user-space from the map_ldt_struct() function in a way so that it is re-usable for PAE paging. Signed-off-by: Joerg Roedel Signed-off-by: Thomas Gleixner Tested-by: Pavel Machek Cc: "H . Peter Anvin" Cc: linux-mm@kvack.org Cc: Linus Torvalds Cc: Andy Lutomirski Cc: Dave Hansen Cc: Josh Poimboeuf Cc: Juergen Gross Cc: Peter Zijlstra Cc: Borislav Petkov Cc: Jiri Kosina Cc: Boris Ostrovsky Cc: Brian Gerst Cc: David Laight Cc: Denys Vlasenko Cc: Eduardo Valentin Cc: Greg KH Cc: Will Deacon Cc: aliguori@amazon.com Cc: daniel.gruss@iaik.tugraz.at Cc: hughd@google.com Cc: keescook@google.com Cc: Andrea Arcangeli Cc: Waiman Long Cc: "David H . Gutteridge" Cc: joro@8bytes.org Link: https://lkml.kernel.org/r/1531906876-13451-36-git-send-email-joro@8bytes.org

x86/ldt: Define LDT_END_ADDR

2018-07-19T23:11:47+00:00

It marks the end of the address-space range reserved for the LDT. The LDT-code will use it when unmapping the LDT for user-space. Signed-off-by: Joerg Roedel Signed-off-by: Thomas Gleixner Tested-by: Pavel Machek Cc: "H . Peter Anvin" Cc: linux-mm@kvack.org Cc: Linus Torvalds Cc: Andy Lutomirski Cc: Dave Hansen Cc: Josh Poimboeuf Cc: Juergen Gross Cc: Peter Zijlstra Cc: Borislav Petkov Cc: Jiri Kosina Cc: Boris Ostrovsky Cc: Brian Gerst Cc: David Laight Cc: Denys Vlasenko Cc: Eduardo Valentin Cc: Greg KH Cc: Will Deacon Cc: aliguori@amazon.com Cc: daniel.gruss@iaik.tugraz.at Cc: hughd@google.com Cc: keescook@google.com Cc: Andrea Arcangeli Cc: Waiman Long Cc: "David H . Gutteridge" Cc: joro@8bytes.org Link: https://lkml.kernel.org/r/1531906876-13451-35-git-send-email-joro@8bytes.org

x86/ldt: Fix support_pte_mask filtering in map_ldt_struct()

2018-04-16T18:20:34+00:00

The |= operator will let us end up with an invalid PTE. Use the correct &= instead. [ The bug was also independently reported by Shuah Khan ] Fixes: fb43d6cb91ef ('x86/mm: Do not auto-massage page protections') Acked-by: Andy Lutomirski Acked-by: Dave Hansen Signed-off-by: Joerg Roedel Signed-off-by: Linus Torvalds

x86/mm: Do not auto-massage page protections

2018-04-12T07:04:22+00:00

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 - boot crash fix from: Tom Lendacky - crash bisected by: Mike Galbraith Signed-off-by: Dave Hansen Reported-and-fixed-by: Arnd Bergmann Fixed-by: Tom Lendacky Bisected-by: Mike Galbraith Cc: Andrea Arcangeli Cc: Andy Lutomirski Cc: Arjan van de Ven Cc: Borislav Petkov Cc: Dan Williams Cc: David Woodhouse Cc: Greg Kroah-Hartman Cc: Hugh Dickins Cc: Josh Poimboeuf Cc: Juergen Gross Cc: Kees Cook Cc: Linus Torvalds Cc: Nadav Amit Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/20180406205509.77E1D7F6@viggo.jf.intel.com Signed-off-by: Ingo Molnar