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authorJoerg Roedel <jroedel@suse.de>2018-07-18 11:40:43 +0200
committerThomas Gleixner <tglx@linutronix.de>2018-07-20 01:11:37 +0200
commit0d2eb73b29996684d5bbb72f85c74b47b4c359f7 (patch)
treed4eeb7755f52f4d52c58c54098c5faca7d862511 /arch/x86/entry
parent8e676ced31e9d1448d3ffc4159586a259cc67f30 (diff)
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
Diffstat (limited to 'arch/x86/entry')
-rw-r--r--arch/x86/entry/entry_32.S11
1 files 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