x86/asm/entry/64: Use negative immediates for stack adjustments

Doing so allows adjustments by 128 bytes (occurring for
REMOVE_PT_GPREGS_FROM_STACK 8 uses) to be expressed with a
single byte immediate.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Cc: Andy Lutomirski <luto@amacapital.net>
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: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/556C660F020000780007FB60@mail.emea.novell.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

diff --git a/arch/x86/include/asm/calling.h b/arch/x86/include/asm/calling.h
index 0d76acc..f4e6308 100644 (file)
--- a/arch/x86/include/asm/calling.h
+++ b/arch/x86/include/asm/calling.h
@@ -89,7 +89,7 @@ For 32-bit we have the following conventions - kernel is built with
 #define SIZEOF_PTREGS  21*8
 
        .macro ALLOC_PT_GPREGS_ON_STACK addskip=0
-       subq    $15*8+\addskip, %rsp
+       addq    $-(15*8+\addskip), %rsp
        .endm
 
        .macro SAVE_C_REGS_HELPER offset=0 rax=1 rcx=1 r8910=1 r11=1
@@ -201,7 +201,7 @@ For 32-bit we have the following conventions - kernel is built with
        .endm
 
        .macro REMOVE_PT_GPREGS_FROM_STACK addskip=0
-       addq $15*8+\addskip, %rsp
+       subq $-(15*8+\addskip), %rsp
        .endm
 
        .macro icebp