1 files changed, 27 insertions, 57 deletions

diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S
index b5c061f8f358..0697ff139837 100644
--- a/arch/x86/kernel/entry_64.S
+++ b/arch/x86/kernel/entry_64.S
@@ -155,11 +155,11 @@ GLOBAL(return_to_handler)
 
         call ftrace_return_to_handler
 
-        movq %rax, 16(%rsp)
+        movq %rax, %rdi
         movq 8(%rsp), %rdx
         movq (%rsp), %rax
-        addq $16, %rsp
-        retq
+        addq $24, %rsp
+        jmp *%rdi
 #endif
 
 
@@ -803,6 +803,10 @@ END(interrupt)
         call \func
         .endm
 
+/*
+ * Interrupt entry/exit should be protected against kprobes
+ */
+        .pushsection .kprobes.text, "ax"
         /*
          * The interrupt stubs push (~vector+0x80) onto the stack and
          * then jump to common_interrupt.
@@ -941,6 +945,10 @@ ENTRY(retint_kernel)
 
         CFI_ENDPROC
 END(common_interrupt)
+/*
+ * End of kprobes section
+ */
+       .popsection
 
 /*
  * APIC interrupts.
@@ -969,8 +977,8 @@ apicinterrupt UV_BAU_MESSAGE \
 #endif
 apicinterrupt LOCAL_TIMER_VECTOR \
         apic_timer_interrupt smp_apic_timer_interrupt
-apicinterrupt GENERIC_INTERRUPT_VECTOR \
-        generic_interrupt smp_generic_interrupt
+apicinterrupt X86_PLATFORM_IPI_VECTOR \
+        x86_platform_ipi smp_x86_platform_ipi
 
 #ifdef CONFIG_SMP
 apicinterrupt INVALIDATE_TLB_VECTOR_START+0 \
@@ -1068,10 +1076,10 @@ ENTRY(\sym)
         TRACE_IRQS_OFF
         movq %rsp,%rdi          /* pt_regs pointer */
         xorl %esi,%esi          /* no error code */
-        PER_CPU(init_tss, %rbp)
-        subq $EXCEPTION_STKSZ, TSS_ist + (\ist - 1) * 8(%rbp)
+        PER_CPU(init_tss, %r12)
+        subq $EXCEPTION_STKSZ, TSS_ist + (\ist - 1) * 8(%r12)
         call \do_sym
-        addq $EXCEPTION_STKSZ, TSS_ist + (\ist - 1) * 8(%rbp)
+        addq $EXCEPTION_STKSZ, TSS_ist + (\ist - 1) * 8(%r12)
         jmp paranoid_exit       /* %ebx: no swapgs flag */
         CFI_ENDPROC
 END(\sym)
@@ -1158,63 +1166,20 @@ bad_gs:
         jmp  2b
         .previous
 
-/*
- * Create a kernel thread.
- *
- * C extern interface:
- *      extern long kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
- *
- * asm input arguments:
- *      rdi: fn, rsi: arg, rdx: flags
- */
-ENTRY(kernel_thread)
-        CFI_STARTPROC
-        FAKE_STACK_FRAME $child_rip
-        SAVE_ALL
-
-        # rdi: flags, rsi: usp, rdx: will be &pt_regs
-        movq %rdx,%rdi
-        orq  kernel_thread_flags(%rip),%rdi
-        movq $-1, %rsi
-        movq %rsp, %rdx
-
-        xorl %r8d,%r8d
-        xorl %r9d,%r9d
-
-        # clone now
-        call do_fork
-        movq %rax,RAX(%rsp)
-        xorl %edi,%edi
-
-        /*
-         * It isn't worth to check for reschedule here,
-         * so internally to the x86_64 port you can rely on kernel_thread()
-         * not to reschedule the child before returning, this avoids the need
-         * of hacks for example to fork off the per-CPU idle tasks.
-         * [Hopefully no generic code relies on the reschedule -AK]
-         */
-        RESTORE_ALL
-        UNFAKE_STACK_FRAME
-        ret
-        CFI_ENDPROC
-END(kernel_thread)
-
-ENTRY(child_rip)
+ENTRY(kernel_thread_helper)
         pushq $0                # fake return address
         CFI_STARTPROC
         /*
          * Here we are in the child and the registers are set as they were
          * at kernel_thread() invocation in the parent.
          */
-        movq %rdi, %rax
-        movq %rsi, %rdi
-        call *%rax
+        call *%rsi
         # exit
         mov %eax, %edi
         call do_exit
         ud2                     # padding for call trace
         CFI_ENDPROC
-END(child_rip)
+END(kernel_thread_helper)
 
 /*
  * execve(). This function needs to use IRET, not SYSRET, to set up all state properly.
@@ -1491,12 +1456,17 @@ error_kernelspace:
         leaq irq_return(%rip),%rcx
         cmpq %rcx,RIP+8(%rsp)
         je error_swapgs
-        movl %ecx,%ecx  /* zero extend */
-        cmpq %rcx,RIP+8(%rsp)
-        je error_swapgs
+        movl %ecx,%eax  /* zero extend */
+        cmpq %rax,RIP+8(%rsp)
+        je bstep_iret
         cmpq $gs_change,RIP+8(%rsp)
         je error_swapgs
         jmp error_sti
+
+bstep_iret:
+        /* Fix truncated RIP */
+        movq %rcx,RIP+8(%rsp)
+        jmp error_swapgs
 END(error_entry)