1 files changed, 22 insertions, 25 deletions

diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S
index eac9b81edfe1..be846d2468f7 100644
--- a/arch/x86/kernel/entry_64.S
+++ b/arch/x86/kernel/entry_64.S
@@ -1203,8 +1203,15 @@ apicinterrupt IRQ_WORK_VECTOR \
 /*
  * Exception entry points.
  */
-.macro idtentry sym do_sym has_error_code:req paranoid=0
+#define INIT_TSS_IST(x) PER_CPU_VAR(init_tss) + (TSS_ist + ((x) - 1) * 8)
+
+.macro idtentry sym do_sym has_error_code:req paranoid=0 shift_ist=-1
 ENTRY(\sym)
+        /* Sanity check */
+        .if \shift_ist != -1 && \paranoid == 0
+        .error "using shift_ist requires paranoid=1"
+        .endif
+
         .if \has_error_code
         XCPT_FRAME
         .else
@@ -1230,8 +1237,12 @@ ENTRY(\sym)
         DEFAULT_FRAME 0
 
         .if \paranoid
+        .if \shift_ist != -1
+        TRACE_IRQS_OFF_DEBUG            /* reload IDT in case of recursion */
+        .else
         TRACE_IRQS_OFF
         .endif
+        .endif
 
         movq %rsp,%rdi                  /* pt_regs pointer */
 
@@ -1242,8 +1253,16 @@ ENTRY(\sym)
         xorl %esi,%esi                  /* no error code */
         .endif
 
+        .if \shift_ist != -1
+        subq $EXCEPTION_STKSZ, INIT_TSS_IST(\shift_ist)
+        .endif
+
         call \do_sym
 
+        .if \shift_ist != -1
+        addq $EXCEPTION_STKSZ, INIT_TSS_IST(\shift_ist)
+        .endif
+
         .if \paranoid
         jmp paranoid_exit               /* %ebx: no swapgs flag */
         .else
@@ -1254,28 +1273,6 @@ ENTRY(\sym)
 END(\sym)
 .endm
 
-#define INIT_TSS_IST(x) PER_CPU_VAR(init_tss) + (TSS_ist + ((x) - 1) * 8)
-.macro paranoidzeroentry_ist sym do_sym ist
-ENTRY(\sym)
-        INTR_FRAME
-        ASM_CLAC
-        PARAVIRT_ADJUST_EXCEPTION_FRAME
-        pushq_cfi $-1           /* ORIG_RAX: no syscall to restart */
-        subq $ORIG_RAX-R15, %rsp
-        CFI_ADJUST_CFA_OFFSET ORIG_RAX-R15
-        call save_paranoid
-        DEFAULT_FRAME 0
-        TRACE_IRQS_OFF_DEBUG
-        movq %rsp,%rdi          /* pt_regs pointer */
-        xorl %esi,%esi          /* no error code */
-        subq $EXCEPTION_STKSZ, INIT_TSS_IST(\ist)
-        call \do_sym
-        addq $EXCEPTION_STKSZ, INIT_TSS_IST(\ist)
-        jmp paranoid_exit       /* %ebx: no swapgs flag */
-        CFI_ENDPROC
-END(\sym)
-.endm
-
 #ifdef CONFIG_TRACING
 .macro trace_idtentry sym do_sym has_error_code:req
 idtentry trace(\sym) trace(\do_sym) has_error_code=\has_error_code
@@ -1460,8 +1457,8 @@ apicinterrupt3 HYPERVISOR_CALLBACK_VECTOR \
  */
         .pushsection .kprobes.text, "ax"
 
-paranoidzeroentry_ist debug do_debug DEBUG_STACK
-paranoidzeroentry_ist int3 do_int3 DEBUG_STACK
+idtentry debug do_debug has_error_code=0 paranoid=1 shift_ist=DEBUG_STACK
+idtentry int3 do_int3 has_error_code=0 paranoid=1 shift_ist=DEBUG_STACK
 idtentry stack_segment do_stack_segment has_error_code=1 paranoid=1
 #ifdef CONFIG_XEN
 idtentry xen_debug do_debug has_error_code=0