Messages in this thread Patch in this message | | | Date | Thu, 19 Jul 2018 16:21:30 -0700 | From | tip-bot for Joerg Roedel <> | Subject | [tip:x86/pti] x86/entry/32: Split off return-to-kernel path |
| |
Commit-ID: 0d2eb73b29996684d5bbb72f85c74b47b4c359f7 Gitweb: https://git.kernel.org/tip/0d2eb73b29996684d5bbb72f85c74b47b4c359f7 Author: Joerg Roedel <jroedel@suse.de> AuthorDate: Wed, 18 Jul 2018 11:40:43 +0200 Committer: Thomas Gleixner <tglx@linutronix.de> CommitDate: Fri, 20 Jul 2018 01:11:37 +0200
x86/entry/32: Split off return-to-kernel path
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: Joerg Roedel <jroedel@suse.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Pavel 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
--- arch/x86/entry/entry_32.S | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-)
diff --git a/arch/x86/entry/entry_32.S b/arch/x86/entry/entry_32.S index 43641310b6e3..7251c4f3e99e 100644 --- a/arch/x86/entry/entry_32.S +++ b/arch/x86/entry/entry_32.S @@ -65,7 +65,7 @@ # define preempt_stop(clobbers) DISABLE_INTERRUPTS(clobbers); TRACE_IRQS_OFF #else # define preempt_stop(clobbers) -# define resume_kernel restore_all +# define resume_kernel restore_all_kernel #endif .macro TRACE_IRQS_IRET @@ -399,9 +399,9 @@ ENTRY(resume_kernel) DISABLE_INTERRUPTS(CLBR_ANY) .Lneed_resched: cmpl $0, PER_CPU_VAR(__preempt_count) - jnz restore_all + jnz restore_all_kernel testl $X86_EFLAGS_IF, PT_EFLAGS(%esp) # interrupts off (exception path) ? - jz restore_all + jz restore_all_kernel call preempt_schedule_irq jmp .Lneed_resched END(resume_kernel) @@ -606,6 +606,11 @@ restore_all: */ INTERRUPT_RETURN +restore_all_kernel: + TRACE_IRQS_IRET + RESTORE_REGS 4 + jmp .Lirq_return + .section .fixup, "ax" ENTRY(iret_exc ) pushl $0 # no error code
| |