x86/entry/64: Merge the POP_C_REGS and POP_EXTRA_REGS macros into a single POP_REGS...

commit 502af0d70843c2a9405d7ba1f79b4b0305aaf5f5 upstream.

The two special, opencoded cases for POP_C_REGS can be handled by ASM
macros.

Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: dan.j.williams@intel.com
Link: http://lkml.kernel.org/r/20180211104949.12992-3-linux@dominikbrodowski.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/x86/entry/calling.h b/arch/x86/entry/calling.h
index 8907a65..3bda317 100644 (file)
--- a/arch/x86/entry/calling.h
+++ b/arch/x86/entry/calling.h
@@ -139,25 +139,32 @@ For 32-bit we have the following conventions - kernel is built with
        xorq %r15, %r15
        .endm
 
-       .macro POP_EXTRA_REGS
+       .macro POP_REGS pop_rdi=1 skip_r11rcx=0
        popq %r15
        popq %r14
        popq %r13
        popq %r12
        popq %rbp
        popq %rbx
-       .endm
-
-       .macro POP_C_REGS
+       .if \skip_r11rcx
+       popq %rsi
+       .else
        popq %r11
+       .endif
        popq %r10
        popq %r9
        popq %r8
        popq %rax
+       .if \skip_r11rcx
+       popq %rsi
+       .else
        popq %rcx
+       .endif
        popq %rdx
        popq %rsi
+       .if \pop_rdi
        popq %rdi
+       .endif
        .endm
 
        .macro icebp

diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
index acd912c..f4d72b8 100644 (file)
--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -330,15 +330,7 @@ GLOBAL(entry_SYSCALL_64_after_hwframe)
 syscall_return_via_sysret:
        /* rcx and r11 are already restored (see code above) */
        UNWIND_HINT_EMPTY
-       POP_EXTRA_REGS
-       popq    %rsi    /* skip r11 */
-       popq    %r10
-       popq    %r9
-       popq    %r8
-       popq    %rax
-       popq    %rsi    /* skip rcx */
-       popq    %rdx
-       popq    %rsi
+       POP_REGS pop_rdi=0 skip_r11rcx=1
 
        /*
         * Now all regs are restored except RSP and RDI.
@@ -631,15 +623,7 @@ GLOBAL(swapgs_restore_regs_and_return_to_usermode)
        ud2
 1:
 #endif
-       POP_EXTRA_REGS
-       popq    %r11
-       popq    %r10
-       popq    %r9
-       popq    %r8
-       popq    %rax
-       popq    %rcx
-       popq    %rdx
-       popq    %rsi
+       POP_REGS pop_rdi=0
 
        /*
         * The stack is now user RDI, orig_ax, RIP, CS, EFLAGS, RSP, SS.
@@ -697,8 +681,7 @@ GLOBAL(restore_regs_and_return_to_kernel)
        ud2
 1:
 #endif
-       POP_EXTRA_REGS
-       POP_C_REGS
+       POP_REGS
        addq    $8, %rsp        /* skip regs->orig_ax */
        INTERRUPT_RETURN
 
@@ -1655,8 +1638,7 @@ end_repeat_nmi:
 nmi_swapgs:
        SWAPGS_UNSAFE_STACK
 nmi_restore:
-       POP_EXTRA_REGS
-       POP_C_REGS
+       POP_REGS
 
        /*
         * Skip orig_ax and the "outermost" frame to point RSP at the "iret"