Commit-ID: 0d2eb73b29996684d5bbb72f85c74b47b4c359f7 Gitweb: https://git.kernel.org/tip/0d2eb73b29996684d5bbb72f85c74b47b4c359f7 Author: Joerg Roedel <[email protected]> AuthorDate: Wed, 18 Jul 2018 11:40:43 +0200 Committer: Thomas Gleixner <[email protected]> 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 <[email protected]> Signed-off-by: Thomas Gleixner <[email protected]> Tested-by: Pavel Machek <[email protected]> Cc: "H . Peter Anvin" <[email protected]> Cc: [email protected] Cc: Linus Torvalds <[email protected]> Cc: Andy Lutomirski <[email protected]> Cc: Dave Hansen <[email protected]> Cc: Josh Poimboeuf <[email protected]> Cc: Juergen Gross <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: Jiri Kosina <[email protected]> Cc: Boris Ostrovsky <[email protected]> Cc: Brian Gerst <[email protected]> Cc: David Laight <[email protected]> Cc: Denys Vlasenko <[email protected]> Cc: Eduardo Valentin <[email protected]> Cc: Greg KH <[email protected]> Cc: Will Deacon <[email protected]> Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: Andrea Arcangeli <[email protected]> Cc: Waiman Long <[email protected]> Cc: "David H . Gutteridge" <[email protected]> Cc: [email protected] Link: https://lkml.kernel.org/r/[email protected] --- 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
