1. 19 Jul, 2018 23 commits
    • Joerg Roedel's avatar
      x86/mm/pae: Populate the user page-table with user pgd's · 9b7b8bbd
      Joerg Roedel authored
      When a PGD entry is populated, make sure to populate it in the user
      page-table too.
      Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
      Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
      Tested-by: default avatarPavel Machek <pavel@ucw.cz>
      Cc: "H . Peter Anvin" <hpa@zytor.com>
      Cc: linux-mm@kvack.org
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Dave Hansen <dave.hansen@intel.com>
      Cc: Josh Poimboeuf <jpoimboe@redhat.com>
      Cc: Juergen Gross <jgross@suse.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Jiri Kosina <jkosina@suse.cz>
      Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
      Cc: Brian Gerst <brgerst@gmail.com>
      Cc: David Laight <David.Laight@aculab.com>
      Cc: Denys Vlasenko <dvlasenk@redhat.com>
      Cc: Eduardo Valentin <eduval@amazon.com>
      Cc: Greg KH <gregkh@linuxfoundation.org>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: aliguori@amazon.com
      Cc: daniel.gruss@iaik.tugraz.at
      Cc: hughd@google.com
      Cc: keescook@google.com
      Cc: Andrea Arcangeli <aarcange@redhat.com>
      Cc: Waiman Long <llong@redhat.com>
      Cc: "David H . Gutteridge" <dhgutteridge@sympatico.ca>
      Cc: joro@8bytes.org
      Link: https://lkml.kernel.org/r/1531906876-13451-23-git-send-email-joro@8bytes.org
      9b7b8bbd
    • Joerg Roedel's avatar
      x86/mm/pae: Populate valid user PGD entries · 6c0df868
      Joerg Roedel authored
      Generic page-table code populates all non-leaf entries with _KERNPG_TABLE
      bits set. This is fine for all paging modes except PAE.
      
      In PAE mode only a subset of the bits is allowed to be set.  Make sure to
      only set allowed bits by masking out the reserved bits.
      Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
      Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
      Tested-by: default avatarPavel Machek <pavel@ucw.cz>
      Cc: "H . Peter Anvin" <hpa@zytor.com>
      Cc: linux-mm@kvack.org
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Dave Hansen <dave.hansen@intel.com>
      Cc: Josh Poimboeuf <jpoimboe@redhat.com>
      Cc: Juergen Gross <jgross@suse.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Jiri Kosina <jkosina@suse.cz>
      Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
      Cc: Brian Gerst <brgerst@gmail.com>
      Cc: David Laight <David.Laight@aculab.com>
      Cc: Denys Vlasenko <dvlasenk@redhat.com>
      Cc: Eduardo Valentin <eduval@amazon.com>
      Cc: Greg KH <gregkh@linuxfoundation.org>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: aliguori@amazon.com
      Cc: daniel.gruss@iaik.tugraz.at
      Cc: hughd@google.com
      Cc: keescook@google.com
      Cc: Andrea Arcangeli <aarcange@redhat.com>
      Cc: Waiman Long <llong@redhat.com>
      Cc: "David H . Gutteridge" <dhgutteridge@sympatico.ca>
      Cc: joro@8bytes.org
      Link: https://lkml.kernel.org/r/1531906876-13451-22-git-send-email-joro@8bytes.org
      6c0df868
    • Joerg Roedel's avatar
      x86/pgtable: Move two more functions from pgtable_64.h to pgtable.h · 76e258ad
      Joerg Roedel authored
      These two functions are required for PTI on 32 bit:
      
      	* pgdp_maps_userspace()
      	* pgd_large()
      
      Also re-implement pgdp_maps_userspace() so that it will work on 64 and 32
      bit kernels.
      Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
      Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
      Tested-by: default avatarPavel Machek <pavel@ucw.cz>
      Cc: "H . Peter Anvin" <hpa@zytor.com>
      Cc: linux-mm@kvack.org
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Dave Hansen <dave.hansen@intel.com>
      Cc: Josh Poimboeuf <jpoimboe@redhat.com>
      Cc: Juergen Gross <jgross@suse.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Jiri Kosina <jkosina@suse.cz>
      Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
      Cc: Brian Gerst <brgerst@gmail.com>
      Cc: David Laight <David.Laight@aculab.com>
      Cc: Denys Vlasenko <dvlasenk@redhat.com>
      Cc: Eduardo Valentin <eduval@amazon.com>
      Cc: Greg KH <gregkh@linuxfoundation.org>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: aliguori@amazon.com
      Cc: daniel.gruss@iaik.tugraz.at
      Cc: hughd@google.com
      Cc: keescook@google.com
      Cc: Andrea Arcangeli <aarcange@redhat.com>
      Cc: Waiman Long <llong@redhat.com>
      Cc: "David H . Gutteridge" <dhgutteridge@sympatico.ca>
      Cc: joro@8bytes.org
      Link: https://lkml.kernel.org/r/1531906876-13451-21-git-send-email-joro@8bytes.org
      76e258ad
    • Joerg Roedel's avatar
      x86/pgtable: Move pti_set_user_pgtbl() to pgtable.h · fcbbd977
      Joerg Roedel authored
      There it is also usable from 32 bit code.
      Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
      Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
      Tested-by: default avatarPavel Machek <pavel@ucw.cz>
      Cc: "H . Peter Anvin" <hpa@zytor.com>
      Cc: linux-mm@kvack.org
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Dave Hansen <dave.hansen@intel.com>
      Cc: Josh Poimboeuf <jpoimboe@redhat.com>
      Cc: Juergen Gross <jgross@suse.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Jiri Kosina <jkosina@suse.cz>
      Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
      Cc: Brian Gerst <brgerst@gmail.com>
      Cc: David Laight <David.Laight@aculab.com>
      Cc: Denys Vlasenko <dvlasenk@redhat.com>
      Cc: Eduardo Valentin <eduval@amazon.com>
      Cc: Greg KH <gregkh@linuxfoundation.org>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: aliguori@amazon.com
      Cc: daniel.gruss@iaik.tugraz.at
      Cc: hughd@google.com
      Cc: keescook@google.com
      Cc: Andrea Arcangeli <aarcange@redhat.com>
      Cc: Waiman Long <llong@redhat.com>
      Cc: "David H . Gutteridge" <dhgutteridge@sympatico.ca>
      Cc: joro@8bytes.org
      Link: https://lkml.kernel.org/r/1531906876-13451-20-git-send-email-joro@8bytes.org
      fcbbd977
    • Joerg Roedel's avatar
      x86/pgtable: Move pgdp kernel/user conversion functions to pgtable.h · 8372d668
      Joerg Roedel authored
      Make them available on 32 bit and clone_pgd_range() happy.
      Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
      Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
      Tested-by: default avatarPavel Machek <pavel@ucw.cz>
      Cc: "H . Peter Anvin" <hpa@zytor.com>
      Cc: linux-mm@kvack.org
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Dave Hansen <dave.hansen@intel.com>
      Cc: Josh Poimboeuf <jpoimboe@redhat.com>
      Cc: Juergen Gross <jgross@suse.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Jiri Kosina <jkosina@suse.cz>
      Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
      Cc: Brian Gerst <brgerst@gmail.com>
      Cc: David Laight <David.Laight@aculab.com>
      Cc: Denys Vlasenko <dvlasenk@redhat.com>
      Cc: Eduardo Valentin <eduval@amazon.com>
      Cc: Greg KH <gregkh@linuxfoundation.org>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: aliguori@amazon.com
      Cc: daniel.gruss@iaik.tugraz.at
      Cc: hughd@google.com
      Cc: keescook@google.com
      Cc: Andrea Arcangeli <aarcange@redhat.com>
      Cc: Waiman Long <llong@redhat.com>
      Cc: "David H . Gutteridge" <dhgutteridge@sympatico.ca>
      Cc: joro@8bytes.org
      Link: https://lkml.kernel.org/r/1531906876-13451-19-git-send-email-joro@8bytes.org
      8372d668
    • Joerg Roedel's avatar
      x86/pgtable/32: Allocate 8k page-tables when PTI is enabled · e3238faf
      Joerg Roedel authored
      Allocate a kernel and a user page-table root when PTI is enabled. Also
      allocate a full page per root for PAE because otherwise the bit to flip in
      CR3 to switch between them would be non-constant, which creates a lot of
      hassle.  Keep that for a later optimization.
      Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
      Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
      Tested-by: default avatarPavel Machek <pavel@ucw.cz>
      Cc: "H . Peter Anvin" <hpa@zytor.com>
      Cc: linux-mm@kvack.org
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Dave Hansen <dave.hansen@intel.com>
      Cc: Josh Poimboeuf <jpoimboe@redhat.com>
      Cc: Juergen Gross <jgross@suse.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Jiri Kosina <jkosina@suse.cz>
      Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
      Cc: Brian Gerst <brgerst@gmail.com>
      Cc: David Laight <David.Laight@aculab.com>
      Cc: Denys Vlasenko <dvlasenk@redhat.com>
      Cc: Eduardo Valentin <eduval@amazon.com>
      Cc: Greg KH <gregkh@linuxfoundation.org>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: aliguori@amazon.com
      Cc: daniel.gruss@iaik.tugraz.at
      Cc: hughd@google.com
      Cc: keescook@google.com
      Cc: Andrea Arcangeli <aarcange@redhat.com>
      Cc: Waiman Long <llong@redhat.com>
      Cc: "David H . Gutteridge" <dhgutteridge@sympatico.ca>
      Cc: joro@8bytes.org
      Link: https://lkml.kernel.org/r/1531906876-13451-18-git-send-email-joro@8bytes.org
      e3238faf
    • Joerg Roedel's avatar
      x86/pgtable/pae: Unshare kernel PMDs when PTI is enabled · 7ffcf149
      Joerg Roedel authored
      With PTI the per-process LDT must be mapped into the kernel address-space
      for each process, which requires separate kernel PMDs per PGD.
      Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
      Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
      Tested-by: default avatarPavel Machek <pavel@ucw.cz>
      Cc: "H . Peter Anvin" <hpa@zytor.com>
      Cc: linux-mm@kvack.org
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Dave Hansen <dave.hansen@intel.com>
      Cc: Josh Poimboeuf <jpoimboe@redhat.com>
      Cc: Juergen Gross <jgross@suse.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Jiri Kosina <jkosina@suse.cz>
      Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
      Cc: Brian Gerst <brgerst@gmail.com>
      Cc: David Laight <David.Laight@aculab.com>
      Cc: Denys Vlasenko <dvlasenk@redhat.com>
      Cc: Eduardo Valentin <eduval@amazon.com>
      Cc: Greg KH <gregkh@linuxfoundation.org>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: aliguori@amazon.com
      Cc: daniel.gruss@iaik.tugraz.at
      Cc: hughd@google.com
      Cc: keescook@google.com
      Cc: Andrea Arcangeli <aarcange@redhat.com>
      Cc: Waiman Long <llong@redhat.com>
      Cc: "David H . Gutteridge" <dhgutteridge@sympatico.ca>
      Cc: joro@8bytes.org
      Link: https://lkml.kernel.org/r/1531906876-13451-17-git-send-email-joro@8bytes.org
      7ffcf149
    • Joerg Roedel's avatar
      x86/pgtable: Rename pti_set_user_pgd() to pti_set_user_pgtbl() · 23b77288
      Joerg Roedel authored
      The way page-table folding is implemented on 32 bit, these functions are
      not only setting, but also PUDs and even PMDs. Give the function a more
      generic name to reflect that.
      Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
      Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
      Tested-by: default avatarPavel Machek <pavel@ucw.cz>
      Cc: "H . Peter Anvin" <hpa@zytor.com>
      Cc: linux-mm@kvack.org
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Dave Hansen <dave.hansen@intel.com>
      Cc: Josh Poimboeuf <jpoimboe@redhat.com>
      Cc: Juergen Gross <jgross@suse.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Jiri Kosina <jkosina@suse.cz>
      Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
      Cc: Brian Gerst <brgerst@gmail.com>
      Cc: David Laight <David.Laight@aculab.com>
      Cc: Denys Vlasenko <dvlasenk@redhat.com>
      Cc: Eduardo Valentin <eduval@amazon.com>
      Cc: Greg KH <gregkh@linuxfoundation.org>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: aliguori@amazon.com
      Cc: daniel.gruss@iaik.tugraz.at
      Cc: hughd@google.com
      Cc: keescook@google.com
      Cc: Andrea Arcangeli <aarcange@redhat.com>
      Cc: Waiman Long <llong@redhat.com>
      Cc: "David H . Gutteridge" <dhgutteridge@sympatico.ca>
      Cc: joro@8bytes.org
      Link: https://lkml.kernel.org/r/1531906876-13451-16-git-send-email-joro@8bytes.org
      23b77288
    • Joerg Roedel's avatar
      x86/entry: Rename update_sp0 to update_task_stack · 252e1a05
      Joerg Roedel authored
      The function does not update sp0 anymore but updates makes the task-stack
      visible for entry code. This is by either writing it to sp1 or by doing a
      hypercall. Rename the function to get rid of the misleading name.
      Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
      Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
      Tested-by: default avatarPavel Machek <pavel@ucw.cz>
      Cc: "H . Peter Anvin" <hpa@zytor.com>
      Cc: linux-mm@kvack.org
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Dave Hansen <dave.hansen@intel.com>
      Cc: Josh Poimboeuf <jpoimboe@redhat.com>
      Cc: Juergen Gross <jgross@suse.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Jiri Kosina <jkosina@suse.cz>
      Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
      Cc: Brian Gerst <brgerst@gmail.com>
      Cc: David Laight <David.Laight@aculab.com>
      Cc: Denys Vlasenko <dvlasenk@redhat.com>
      Cc: Eduardo Valentin <eduval@amazon.com>
      Cc: Greg KH <gregkh@linuxfoundation.org>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: aliguori@amazon.com
      Cc: daniel.gruss@iaik.tugraz.at
      Cc: hughd@google.com
      Cc: keescook@google.com
      Cc: Andrea Arcangeli <aarcange@redhat.com>
      Cc: Waiman Long <llong@redhat.com>
      Cc: "David H . Gutteridge" <dhgutteridge@sympatico.ca>
      Cc: joro@8bytes.org
      Link: https://lkml.kernel.org/r/1531906876-13451-15-git-send-email-joro@8bytes.org
      252e1a05
    • Joerg Roedel's avatar
      x86/entry/32: Add PTI CR3 switches to NMI handler code · b65bef40
      Joerg Roedel authored
      The NMI handler is special, as it needs to leave with the same CR3 as it
      was entered with. This is required because the NMI can happen within kernel
      context but with user CR3 already loaded, i.e. after switching to user CR3
      but before returning to user space.
      Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
      Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
      Tested-by: default avatarPavel Machek <pavel@ucw.cz>
      Cc: "H . Peter Anvin" <hpa@zytor.com>
      Cc: linux-mm@kvack.org
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Dave Hansen <dave.hansen@intel.com>
      Cc: Josh Poimboeuf <jpoimboe@redhat.com>
      Cc: Juergen Gross <jgross@suse.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Jiri Kosina <jkosina@suse.cz>
      Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
      Cc: Brian Gerst <brgerst@gmail.com>
      Cc: David Laight <David.Laight@aculab.com>
      Cc: Denys Vlasenko <dvlasenk@redhat.com>
      Cc: Eduardo Valentin <eduval@amazon.com>
      Cc: Greg KH <gregkh@linuxfoundation.org>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: aliguori@amazon.com
      Cc: daniel.gruss@iaik.tugraz.at
      Cc: hughd@google.com
      Cc: keescook@google.com
      Cc: Andrea Arcangeli <aarcange@redhat.com>
      Cc: Waiman Long <llong@redhat.com>
      Cc: "David H . Gutteridge" <dhgutteridge@sympatico.ca>
      Cc: joro@8bytes.org
      Link: https://lkml.kernel.org/r/1531906876-13451-14-git-send-email-joro@8bytes.org
      b65bef40
    • Joerg Roedel's avatar
      x86/entry/32: Add PTI cr3 switch to non-NMI entry/exit points · e464fb9f
      Joerg Roedel authored
      Add unconditional cr3 switches between user and kernel cr3 to all non-NMI
      entry and exit points.
      Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
      Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
      Tested-by: default avatarPavel Machek <pavel@ucw.cz>
      Cc: "H . Peter Anvin" <hpa@zytor.com>
      Cc: linux-mm@kvack.org
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Dave Hansen <dave.hansen@intel.com>
      Cc: Josh Poimboeuf <jpoimboe@redhat.com>
      Cc: Juergen Gross <jgross@suse.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Jiri Kosina <jkosina@suse.cz>
      Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
      Cc: Brian Gerst <brgerst@gmail.com>
      Cc: David Laight <David.Laight@aculab.com>
      Cc: Denys Vlasenko <dvlasenk@redhat.com>
      Cc: Eduardo Valentin <eduval@amazon.com>
      Cc: Greg KH <gregkh@linuxfoundation.org>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: aliguori@amazon.com
      Cc: daniel.gruss@iaik.tugraz.at
      Cc: hughd@google.com
      Cc: keescook@google.com
      Cc: Andrea Arcangeli <aarcange@redhat.com>
      Cc: Waiman Long <llong@redhat.com>
      Cc: "David H . Gutteridge" <dhgutteridge@sympatico.ca>
      Cc: joro@8bytes.org
      Link: https://lkml.kernel.org/r/1531906876-13451-13-git-send-email-joro@8bytes.org
      e464fb9f
    • Joerg Roedel's avatar
      x86/entry/32: Simplify debug entry point · 929b44eb
      Joerg Roedel authored
      The common exception entry code now handles the entry-from-sysenter stack
      situation and makes sure to leave with the same stack as it entered the
      kernel.
      
      So there is no need anymore for the special handling in the debug entry
      code.
      Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
      Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
      Tested-by: default avatarPavel Machek <pavel@ucw.cz>
      Cc: "H . Peter Anvin" <hpa@zytor.com>
      Cc: linux-mm@kvack.org
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Dave Hansen <dave.hansen@intel.com>
      Cc: Josh Poimboeuf <jpoimboe@redhat.com>
      Cc: Juergen Gross <jgross@suse.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Jiri Kosina <jkosina@suse.cz>
      Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
      Cc: Brian Gerst <brgerst@gmail.com>
      Cc: David Laight <David.Laight@aculab.com>
      Cc: Denys Vlasenko <dvlasenk@redhat.com>
      Cc: Eduardo Valentin <eduval@amazon.com>
      Cc: Greg KH <gregkh@linuxfoundation.org>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: aliguori@amazon.com
      Cc: daniel.gruss@iaik.tugraz.at
      Cc: hughd@google.com
      Cc: keescook@google.com
      Cc: Andrea Arcangeli <aarcange@redhat.com>
      Cc: Waiman Long <llong@redhat.com>
      Cc: "David H . Gutteridge" <dhgutteridge@sympatico.ca>
      Cc: joro@8bytes.org
      Link: https://lkml.kernel.org/r/1531906876-13451-12-git-send-email-joro@8bytes.org
      929b44eb
    • Joerg Roedel's avatar
      x86/entry/32: Handle Entry from Kernel-Mode on Entry-Stack · b92a165d
      Joerg Roedel authored
      It is possible that the kernel is entered from kernel-mode and on the
      entry-stack. The most common way this happens is when an exception is
      triggered while loading the user-space segment registers on the
      kernel-to-userspace exit path.
      
      The segment loading needs to be done after the entry-stack switch, because
      the stack-switch needs kernel %fs for per_cpu access.
      
      When this happens, make sure to leave the kernel with the entry-stack
      again, so that the interrupted code-path runs on the right stack when
      switching to the user-cr3.
      
      Detect this condition on kernel-entry by checking CS.RPL and %esp, and if
      it happens, copy over the complete content of the entry stack to the
      task-stack.  This needs to be done because once the exception handler is
      entereed, the task might be scheduled out or even migrated to a different
      CPU, so this cannot rely on the entry-stack contents. Leave a marker in the
      stack-frame to detect this condition on the exit path.
      
      On the exit path the copy is reversed, copy all of the remaining task-stack
      back to the entry-stack and switch to it.
      Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
      Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
      Tested-by: default avatarPavel Machek <pavel@ucw.cz>
      Cc: "H . Peter Anvin" <hpa@zytor.com>
      Cc: linux-mm@kvack.org
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Dave Hansen <dave.hansen@intel.com>
      Cc: Josh Poimboeuf <jpoimboe@redhat.com>
      Cc: Juergen Gross <jgross@suse.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Jiri Kosina <jkosina@suse.cz>
      Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
      Cc: Brian Gerst <brgerst@gmail.com>
      Cc: David Laight <David.Laight@aculab.com>
      Cc: Denys Vlasenko <dvlasenk@redhat.com>
      Cc: Eduardo Valentin <eduval@amazon.com>
      Cc: Greg KH <gregkh@linuxfoundation.org>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: aliguori@amazon.com
      Cc: daniel.gruss@iaik.tugraz.at
      Cc: hughd@google.com
      Cc: keescook@google.com
      Cc: Andrea Arcangeli <aarcange@redhat.com>
      Cc: Waiman Long <llong@redhat.com>
      Cc: "David H . Gutteridge" <dhgutteridge@sympatico.ca>
      Cc: joro@8bytes.org
      Link: https://lkml.kernel.org/r/1531906876-13451-11-git-send-email-joro@8bytes.org
      b92a165d
    • Joerg Roedel's avatar
      x86/entry/32: Introduce SAVE_ALL_NMI and RESTORE_ALL_NMI · 8b376fae
      Joerg Roedel authored
      These macros will be used in the NMI handler code and replace plain
      SAVE_ALL and RESTORE_REGS there.
      
      The NMI-specific CR3-switch will be added to these macros later.
      Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
      Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
      Tested-by: default avatarPavel Machek <pavel@ucw.cz>
      Cc: "H . Peter Anvin" <hpa@zytor.com>
      Cc: linux-mm@kvack.org
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Dave Hansen <dave.hansen@intel.com>
      Cc: Josh Poimboeuf <jpoimboe@redhat.com>
      Cc: Juergen Gross <jgross@suse.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Jiri Kosina <jkosina@suse.cz>
      Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
      Cc: Brian Gerst <brgerst@gmail.com>
      Cc: David Laight <David.Laight@aculab.com>
      Cc: Denys Vlasenko <dvlasenk@redhat.com>
      Cc: Eduardo Valentin <eduval@amazon.com>
      Cc: Greg KH <gregkh@linuxfoundation.org>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: aliguori@amazon.com
      Cc: daniel.gruss@iaik.tugraz.at
      Cc: hughd@google.com
      Cc: keescook@google.com
      Cc: Andrea Arcangeli <aarcange@redhat.com>
      Cc: Waiman Long <llong@redhat.com>
      Cc: "David H . Gutteridge" <dhgutteridge@sympatico.ca>
      Cc: joro@8bytes.org
      Link: https://lkml.kernel.org/r/1531906876-13451-10-git-send-email-joro@8bytes.org
      8b376fae
    • Joerg Roedel's avatar
      x86/entry/32: Leave the kernel via trampoline stack · e5862d05
      Joerg Roedel authored
      Switch back to the trampoline stack before returning to userspace.
      Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
      Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
      Tested-by: default avatarPavel Machek <pavel@ucw.cz>
      Cc: "H . Peter Anvin" <hpa@zytor.com>
      Cc: linux-mm@kvack.org
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Dave Hansen <dave.hansen@intel.com>
      Cc: Josh Poimboeuf <jpoimboe@redhat.com>
      Cc: Juergen Gross <jgross@suse.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Jiri Kosina <jkosina@suse.cz>
      Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
      Cc: Brian Gerst <brgerst@gmail.com>
      Cc: David Laight <David.Laight@aculab.com>
      Cc: Denys Vlasenko <dvlasenk@redhat.com>
      Cc: Eduardo Valentin <eduval@amazon.com>
      Cc: Greg KH <gregkh@linuxfoundation.org>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: aliguori@amazon.com
      Cc: daniel.gruss@iaik.tugraz.at
      Cc: hughd@google.com
      Cc: keescook@google.com
      Cc: Andrea Arcangeli <aarcange@redhat.com>
      Cc: Waiman Long <llong@redhat.com>
      Cc: "David H . Gutteridge" <dhgutteridge@sympatico.ca>
      Cc: joro@8bytes.org
      Link: https://lkml.kernel.org/r/1531906876-13451-9-git-send-email-joro@8bytes.org
      e5862d05
    • Joerg Roedel's avatar
      x86/entry/32: Enter the kernel via trampoline stack · 45d7b255
      Joerg Roedel authored
      Use the entry-stack as a trampoline to enter the kernel. The entry-stack is
      already in the cpu_entry_area and will be mapped to userspace when PTI is
      enabled.
      Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
      Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
      Tested-by: default avatarPavel Machek <pavel@ucw.cz>
      Cc: "H . Peter Anvin" <hpa@zytor.com>
      Cc: linux-mm@kvack.org
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Dave Hansen <dave.hansen@intel.com>
      Cc: Josh Poimboeuf <jpoimboe@redhat.com>
      Cc: Juergen Gross <jgross@suse.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Jiri Kosina <jkosina@suse.cz>
      Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
      Cc: Brian Gerst <brgerst@gmail.com>
      Cc: David Laight <David.Laight@aculab.com>
      Cc: Denys Vlasenko <dvlasenk@redhat.com>
      Cc: Eduardo Valentin <eduval@amazon.com>
      Cc: Greg KH <gregkh@linuxfoundation.org>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: aliguori@amazon.com
      Cc: daniel.gruss@iaik.tugraz.at
      Cc: hughd@google.com
      Cc: keescook@google.com
      Cc: Andrea Arcangeli <aarcange@redhat.com>
      Cc: Waiman Long <llong@redhat.com>
      Cc: "David H . Gutteridge" <dhgutteridge@sympatico.ca>
      Cc: joro@8bytes.org
      Link: https://lkml.kernel.org/r/1531906876-13451-8-git-send-email-joro@8bytes.org
      45d7b255
    • Joerg Roedel's avatar
      x86/entry/32: Split off return-to-kernel path · 0d2eb73b
      Joerg Roedel authored
      Use a separate return path when returning to the kernel.
      
      This allows to put the PTI cr3-switch and the switch to the entry-stack
      into the return-to-user path without further checking.
      Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
      Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
      Tested-by: default avatarPavel Machek <pavel@ucw.cz>
      Cc: "H . Peter Anvin" <hpa@zytor.com>
      Cc: linux-mm@kvack.org
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Dave Hansen <dave.hansen@intel.com>
      Cc: Josh Poimboeuf <jpoimboe@redhat.com>
      Cc: Juergen Gross <jgross@suse.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Jiri Kosina <jkosina@suse.cz>
      Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
      Cc: Brian Gerst <brgerst@gmail.com>
      Cc: David Laight <David.Laight@aculab.com>
      Cc: Denys Vlasenko <dvlasenk@redhat.com>
      Cc: Eduardo Valentin <eduval@amazon.com>
      Cc: Greg KH <gregkh@linuxfoundation.org>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: aliguori@amazon.com
      Cc: daniel.gruss@iaik.tugraz.at
      Cc: hughd@google.com
      Cc: keescook@google.com
      Cc: Andrea Arcangeli <aarcange@redhat.com>
      Cc: Waiman Long <llong@redhat.com>
      Cc: "David H . Gutteridge" <dhgutteridge@sympatico.ca>
      Cc: joro@8bytes.org
      Link: https://lkml.kernel.org/r/1531906876-13451-7-git-send-email-joro@8bytes.org
      0d2eb73b
    • Joerg Roedel's avatar
      x86/entry/32: Unshare NMI return path · 8e676ced
      Joerg Roedel authored
      NMI will no longer use most of the shared return path, because NMI needs
      special handling when the CR3 switches for PTI are added. Prepare for that
      change.
      Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
      Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
      Tested-by: default avatarPavel Machek <pavel@ucw.cz>
      Cc: "H . Peter Anvin" <hpa@zytor.com>
      Cc: linux-mm@kvack.org
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Dave Hansen <dave.hansen@intel.com>
      Cc: Josh Poimboeuf <jpoimboe@redhat.com>
      Cc: Juergen Gross <jgross@suse.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Jiri Kosina <jkosina@suse.cz>
      Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
      Cc: Brian Gerst <brgerst@gmail.com>
      Cc: David Laight <David.Laight@aculab.com>
      Cc: Denys Vlasenko <dvlasenk@redhat.com>
      Cc: Eduardo Valentin <eduval@amazon.com>
      Cc: Greg KH <gregkh@linuxfoundation.org>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: aliguori@amazon.com
      Cc: daniel.gruss@iaik.tugraz.at
      Cc: hughd@google.com
      Cc: keescook@google.com
      Cc: Andrea Arcangeli <aarcange@redhat.com>
      Cc: Waiman Long <llong@redhat.com>
      Cc: "David H . Gutteridge" <dhgutteridge@sympatico.ca>
      Cc: joro@8bytes.org
      Link: https://lkml.kernel.org/r/1531906876-13451-6-git-send-email-joro@8bytes.org
      8e676ced
    • Joerg Roedel's avatar
      x86/entry/32: Put ESPFIX code into a macro · 46eabca2
      Joerg Roedel authored
      This makes it easier to split up the shared iret code path.
      Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
      Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
      Tested-by: default avatarPavel Machek <pavel@ucw.cz>
      Cc: "H . Peter Anvin" <hpa@zytor.com>
      Cc: linux-mm@kvack.org
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Dave Hansen <dave.hansen@intel.com>
      Cc: Josh Poimboeuf <jpoimboe@redhat.com>
      Cc: Juergen Gross <jgross@suse.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Jiri Kosina <jkosina@suse.cz>
      Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
      Cc: Brian Gerst <brgerst@gmail.com>
      Cc: David Laight <David.Laight@aculab.com>
      Cc: Denys Vlasenko <dvlasenk@redhat.com>
      Cc: Eduardo Valentin <eduval@amazon.com>
      Cc: Greg KH <gregkh@linuxfoundation.org>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: aliguori@amazon.com
      Cc: daniel.gruss@iaik.tugraz.at
      Cc: hughd@google.com
      Cc: keescook@google.com
      Cc: Andrea Arcangeli <aarcange@redhat.com>
      Cc: Waiman Long <llong@redhat.com>
      Cc: "David H . Gutteridge" <dhgutteridge@sympatico.ca>
      Cc: joro@8bytes.org
      Link: https://lkml.kernel.org/r/1531906876-13451-5-git-send-email-joro@8bytes.org
      46eabca2
    • Joerg Roedel's avatar
      x86/entry/32: Load task stack from x86_tss.sp1 in SYSENTER handler · a6b744f3
      Joerg Roedel authored
      x86_tss.sp0 will be used to point to the entry stack later to use it as a
      trampoline stack for other kernel entry points besides SYSENTER.
      
      So store the real task stack pointer in x86_tss.sp1, which is otherwise
      unused by the hardware, as Linux doesn't make use of Ring 1.
      Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
      Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
      Tested-by: default avatarPavel Machek <pavel@ucw.cz>
      Cc: "H . Peter Anvin" <hpa@zytor.com>
      Cc: linux-mm@kvack.org
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Dave Hansen <dave.hansen@intel.com>
      Cc: Josh Poimboeuf <jpoimboe@redhat.com>
      Cc: Juergen Gross <jgross@suse.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Jiri Kosina <jkosina@suse.cz>
      Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
      Cc: Brian Gerst <brgerst@gmail.com>
      Cc: David Laight <David.Laight@aculab.com>
      Cc: Denys Vlasenko <dvlasenk@redhat.com>
      Cc: Eduardo Valentin <eduval@amazon.com>
      Cc: Greg KH <gregkh@linuxfoundation.org>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: aliguori@amazon.com
      Cc: daniel.gruss@iaik.tugraz.at
      Cc: hughd@google.com
      Cc: keescook@google.com
      Cc: Andrea Arcangeli <aarcange@redhat.com>
      Cc: Waiman Long <llong@redhat.com>
      Cc: "David H . Gutteridge" <dhgutteridge@sympatico.ca>
      Cc: joro@8bytes.org
      Link: https://lkml.kernel.org/r/1531906876-13451-4-git-send-email-joro@8bytes.org
      a6b744f3
    • Joerg Roedel's avatar
      x86/entry/32: Rename TSS_sysenter_sp0 to TSS_entry2task_stack · ae2e565b
      Joerg Roedel authored
      The stack address doesn't need to be stored in tss.sp0 if the stack is
      switched manually like on sysenter. Rename the offset so that it still
      makes sense when its location is changed in later patches.
      
      This stackk will also be used for all kernel-entry points, not just
      sysenter. Reflect that and the fact that it is the offset to the task-stack
      location in the name as well.
      Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
      Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
      Tested-by: default avatarPavel Machek <pavel@ucw.cz>
      Cc: "H . Peter Anvin" <hpa@zytor.com>
      Cc: linux-mm@kvack.org
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Dave Hansen <dave.hansen@intel.com>
      Cc: Josh Poimboeuf <jpoimboe@redhat.com>
      Cc: Juergen Gross <jgross@suse.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Jiri Kosina <jkosina@suse.cz>
      Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
      Cc: Brian Gerst <brgerst@gmail.com>
      Cc: David Laight <David.Laight@aculab.com>
      Cc: Denys Vlasenko <dvlasenk@redhat.com>
      Cc: Eduardo Valentin <eduval@amazon.com>
      Cc: Greg KH <gregkh@linuxfoundation.org>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: aliguori@amazon.com
      Cc: daniel.gruss@iaik.tugraz.at
      Cc: hughd@google.com
      Cc: keescook@google.com
      Cc: Andrea Arcangeli <aarcange@redhat.com>
      Cc: Waiman Long <llong@redhat.com>
      Cc: "David H . Gutteridge" <dhgutteridge@sympatico.ca>
      Cc: joro@8bytes.org
      Link: https://lkml.kernel.org/r/1531906876-13451-3-git-send-email-joro@8bytes.org
      ae2e565b
    • Joerg Roedel's avatar
      x86/asm-offsets: Move TSS_sp0 and TSS_sp1 to asm-offsets.c · 9e97b73f
      Joerg Roedel authored
      These offsets will be used in 32 bit assembly code as well, so make them
      available for all of x86 code.
      Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
      Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
      Tested-by: default avatarPavel Machek <pavel@ucw.cz>
      Reviewed-by: default avatarAndy Lutomirski <luto@kernel.org>
      Cc: "H . Peter Anvin" <hpa@zytor.com>
      Cc: linux-mm@kvack.org
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Dave Hansen <dave.hansen@intel.com>
      Cc: Josh Poimboeuf <jpoimboe@redhat.com>
      Cc: Juergen Gross <jgross@suse.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Jiri Kosina <jkosina@suse.cz>
      Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
      Cc: Brian Gerst <brgerst@gmail.com>
      Cc: David Laight <David.Laight@aculab.com>
      Cc: Denys Vlasenko <dvlasenk@redhat.com>
      Cc: Eduardo Valentin <eduval@amazon.com>
      Cc: Greg KH <gregkh@linuxfoundation.org>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: aliguori@amazon.com
      Cc: daniel.gruss@iaik.tugraz.at
      Cc: hughd@google.com
      Cc: keescook@google.com
      Cc: Andrea Arcangeli <aarcange@redhat.com>
      Cc: Waiman Long <llong@redhat.com>
      Cc: "David H . Gutteridge" <dhgutteridge@sympatico.ca>
      Cc: joro@8bytes.org
      Link: https://lkml.kernel.org/r/1531906876-13451-2-git-send-email-joro@8bytes.org
      9e97b73f
    • Jiang Biao's avatar
      x86/speculation: Remove SPECTRE_V2_IBRS in enum spectre_v2_mitigation · d9f4426c
      Jiang Biao authored
      SPECTRE_V2_IBRS in enum spectre_v2_mitigation is never used. Remove it.
      Signed-off-by: default avatarJiang Biao <jiang.biao2@zte.com.cn>
      Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
      Cc: hpa@zytor.com
      Cc: dwmw2@amazon.co.uk
      Cc: konrad.wilk@oracle.com
      Cc: bp@suse.de
      Cc: zhong.weidong@zte.com.cn
      Link: https://lkml.kernel.org/r/1531872194-39207-1-git-send-email-jiang.biao2@zte.com.cn
      d9f4426c
  2. 16 Jul, 2018 2 commits
    • Jiang Biao's avatar
      x86/pti: Make pti_set_kernel_image_nonglobal() static · 21279157
      Jiang Biao authored
      pti_set_kernel_image_nonglobal() is only used in pti.c, make it static.
      Signed-off-by: default avatarJiang Biao <jiang.biao2@zte.com.cn>
      Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
      Acked-by: default avatarDave Hansen <dave.hansen@linux.intel.com>
      Cc: luto@kernel.org
      Cc: hpa@zytor.com
      Cc: albcamus@gmail.com
      Cc: zhong.weidong@zte.com.cn
      Link: https://lkml.kernel.org/r/1531713820-24544-4-git-send-email-jiang.biao2@zte.com.cn
      21279157
    • Ville Syrjälä's avatar
      x86/apm: Don't access __preempt_count with zeroed fs · 6f6060a5
      Ville Syrjälä authored
      APM_DO_POP_SEGS does not restore fs/gs which were zeroed by
      APM_DO_ZERO_SEGS. Trying to access __preempt_count with
      zeroed fs doesn't really work.
      
      Move the ibrs call outside the APM_DO_SAVE_SEGS/APM_DO_RESTORE_SEGS
      invocations so that fs is actually restored before calling
      preempt_enable().
      
      Fixes the following sort of oopses:
      [    0.313581] general protection fault: 0000 [#1] PREEMPT SMP
      [    0.313803] Modules linked in:
      [    0.314040] CPU: 0 PID: 268 Comm: kapmd Not tainted 4.16.0-rc1-triton-bisect-00090-gdd84441a #19
      [    0.316161] EIP: __apm_bios_call_simple+0xc8/0x170
      [    0.316161] EFLAGS: 00210016 CPU: 0
      [    0.316161] EAX: 00000102 EBX: 00000000 ECX: 00000102 EDX: 00000000
      [    0.316161] ESI: 0000530e EDI: dea95f64 EBP: dea95f18 ESP: dea95ef0
      [    0.316161]  DS: 007b ES: 007b FS: 0000 GS: 0000 SS: 0068
      [    0.316161] CR0: 80050033 CR2: 00000000 CR3: 015d3000 CR4: 000006d0
      [    0.316161] Call Trace:
      [    0.316161]  ? cpumask_weight.constprop.15+0x20/0x20
      [    0.316161]  on_cpu0+0x44/0x70
      [    0.316161]  apm+0x54e/0x720
      [    0.316161]  ? __switch_to_asm+0x26/0x40
      [    0.316161]  ? __schedule+0x17d/0x590
      [    0.316161]  kthread+0xc0/0xf0
      [    0.316161]  ? proc_apm_show+0x150/0x150
      [    0.316161]  ? kthread_create_worker_on_cpu+0x20/0x20
      [    0.316161]  ret_from_fork+0x2e/0x38
      [    0.316161] Code: da 8e c2 8e e2 8e ea 57 55 2e ff 1d e0 bb 5d b1 0f 92 c3 5d 5f 07 1f 89 47 0c 90 8d b4 26 00 00 00 00 90 8d b4 26 00 00 00 00 90 <64> ff 0d 84 16 5c b1 74 7f 8b 45 dc 8e e0 8b 45 d8 8e e8 8b 45
      [    0.316161] EIP: __apm_bios_call_simple+0xc8/0x170 SS:ESP: 0068:dea95ef0
      [    0.316161] ---[ end trace 656253db2deaa12c ]---
      
      Fixes: dd84441a ("x86/speculation: Use IBRS if available before calling into firmware")
      Signed-off-by: default avatarVille Syrjälä <ville.syrjala@linux.intel.com>
      Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
      Cc: stable@vger.kernel.org
      Cc:  David Woodhouse <dwmw@amazon.co.uk>
      Cc:  "H. Peter Anvin" <hpa@zytor.com>
      Cc:  x86@kernel.org
      Cc: David Woodhouse <dwmw@amazon.co.uk>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Link: https://lkml.kernel.org/r/20180709133534.5963-1-ville.syrjala@linux.intel.com
      6f6060a5
  3. 15 Jul, 2018 1 commit
    • Hugh Dickins's avatar
      x86/events/intel/ds: Fix bts_interrupt_threshold alignment · 2c991e40
      Hugh Dickins authored
      Markus reported that BTS is sporadically missing the tail of the trace
      in the perf_event data buffer: [decode error (1): instruction overflow]
      shown in GDB; and bisected it to the conversion of debug_store to PTI.
      
      A little "optimization" crept into alloc_bts_buffer(), which mistakenly
      placed bts_interrupt_threshold away from the 24-byte record boundary.
      Intel SDM Vol 3B 17.4.9 says "This address must point to an offset from
      the BTS buffer base that is a multiple of the BTS record size."
      
      Revert "max" from a byte count to a record count, to calculate the
      bts_interrupt_threshold correctly: which turns out to fix problem seen.
      
      Fixes: c1961a46 ("x86/events/intel/ds: Map debug buffers in cpu_entry_area")
      Reported-and-tested-by: default avatarMarkus T Metzger <markus.t.metzger@intel.com>
      Signed-off-by: default avatarHugh Dickins <hughd@google.com>
      Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
      Cc: Alexander Shishkin <alexander.shishkin@intel.com>
      Cc: Andi Kleen <andi.kleen@intel.com>
      Cc: Dave Hansen <dave.hansen@intel.com>
      Cc: Stephane Eranian <eranian@google.com>
      Cc: stable@vger.kernel.org # v4.14+
      Link: https://lkml.kernel.org/r/alpine.LSU.2.11.1807141248290.1614@eggly.anvils
      2c991e40
  4. 14 Jul, 2018 14 commits