xnu-3247.1.106.tar.gz

[apple/xnu.git] / osfmk / x86_64 / idt64.s

diff --git a/osfmk/x86_64/idt64.s b/osfmk/x86_64/idt64.s
index 3eaf156d8b351a732d4fdbeb4c7371fafe41087f..0dc07f85020b2b1082e3ea3f663ee23987adc180 100644 (file)
--- a/osfmk/x86_64/idt64.s
+++ b/osfmk/x86_64/idt64.s
@@ -278,8 +278,11 @@ L_dispatch_U32_after_fault:
        mov     R64_TRAPFN(%r15), %rdx          /* %rdx := trapfn for later */
 
 L_common_dispatch:
-       cld              /* Ensure the direction flag is clear in the kernel */
-
+       cld             /* Ensure the direction flag is clear in the kernel */
+       cmpl    $0, EXT(pmap_smap_enabled)(%rip)
+       je      1f
+       clac            /* Clear EFLAGS.AC if SMAP is present/enabled */
+1:
        /*
         * On entering the kernel, we don't need to switch cr3
         * because the kernel shares the user's address space.
@@ -293,36 +296,37 @@ L_common_dispatch:
        mov     %gs:CPU_KERNEL_CR3, %rcx
        mov     %rcx, %gs:CPU_ACTIVE_CR3
        test    $3, %esi                        /* user/kernel? */
-       jz      1f                              /* skip cr3 reload from kernel */
+       jz      2f                              /* skip cr3 reload from kernel */
        xor     %rbp, %rbp
        cmpl    $0, EXT(no_shared_cr3)(%rip)
-       je      1f
+       je      2f
        mov     %rcx, %cr3                      /* load kernel cr3 */
-       jmp     2f                              /* and skip tlb flush test */
-1:
+       jmp     4f                              /* and skip tlb flush test */
+2:
        mov     %gs:CPU_ACTIVE_CR3+4, %rcx
        shr     $32, %rcx
        testl   %ecx, %ecx
-       jz      2f
+       jz      4f
        movl    $0, %gs:CPU_TLB_INVALID
        testl   $(1<<16), %ecx                  /* Global? */
-       jz      11f
+       jz      3f
        mov     %cr4, %rcx      /* RMWW CR4, for lack of an alternative*/
        and     $(~CR4_PGE), %rcx
        mov     %rcx, %cr4
        or      $(CR4_PGE), %rcx
        mov     %rcx, %cr4
-       jmp     2f
-
-11:    mov     %cr3, %rcx
+       jmp     4f
+3:
+       mov     %cr3, %rcx
        mov     %rcx, %cr3
-2:
+4:
        mov     %gs:CPU_ACTIVE_THREAD, %rcx     /* Get the active thread */
+       movl    $-1, TH_IOTIER_OVERRIDE(%rcx)   /* Reset IO tier override to -1 before handling trap */
        cmpq    $0, TH_PCB_IDS(%rcx)    /* Is there a debug register state? */
-       je      3f
+       je      5f
        xor     %ecx, %ecx              /* If so, reset DR7 (the control) */
        mov     %rcx, %dr7
-3:
+5:
        incl    %gs:hwIntCnt(,%ebx,4)           // Bump the trap/intr count
        /* Dispatch the designated handler */
        jmp     *%rdx
@@ -393,7 +397,7 @@ L_32bit_return:
        je      1f
        cli
        POSTCODE2(0x6432)
-       CCALL1(panic_idt64, %rsp)
+       CCALL1(panic_idt64, %r15)
 1:
 #endif /* DEBUG_IDT64 */
 
@@ -559,6 +563,7 @@ Entry(idt64_mdep_scall)
        pushq   $(MACHDEP_INT)
        jmp     L_32bit_entry_check
 
+/* Programmed into MSR_IA32_LSTAR by mp_desc.c */
 Entry(hi64_syscall)
 Entry(idt64_syscall)
 L_syscall_continue:
@@ -1014,6 +1019,7 @@ Entry(hndl_alltraps)
 
        /* Check for active vtimers in the current task */
        mov     %gs:CPU_ACTIVE_THREAD, %rcx
+       movl    $-1, TH_IOTIER_OVERRIDE(%rcx)   /* Reset IO tier override to -1 before handling trap/exception */
        mov     TH_TASK(%rcx), %rbx
        TASK_VTIMER_CHECK(%rbx, %rcx)
 
@@ -1022,12 +1028,10 @@ Entry(hndl_alltraps)
        cli                                     /* hold off intrs - critical section */
        xorl    %ecx, %ecx                      /* don't check if we're in the PFZ */
 
-#define CLI cli
-#define STI sti
 
 Entry(return_from_trap)
        movq    %gs:CPU_ACTIVE_THREAD,%r15      /* Get current thread */
-       movl    $-1, TH_IOTIER_OVERRIDE(%r15)   /* Clear IO tier override before returning to userspace */
+       movl    $-1, TH_IOTIER_OVERRIDE(%r15)   /* Reset IO tier override to -1 before returning to userspace */
        cmpl    $0, TH_RWLOCK_COUNT(%r15)       /* Check if current thread has pending RW locks held */
        jz      1f
        xorq    %rbp, %rbp              /* clear framepointer */
@@ -1061,13 +1065,13 @@ L_return_from_trap_with_ast:
        movl    %eax, R64_RBX(%r15)     /* let the PFZ know we've pended an AST */
        jmp     EXT(return_to_user)
 2:     
-       STI                             /* interrupts always enabled on return to user mode */
+       sti                             /* interrupts always enabled on return to user mode */
 
        xor     %edi, %edi              /* zero %rdi */
        xorq    %rbp, %rbp              /* clear framepointer */
        CCALL(i386_astintr)             /* take the AST */
 
-       CLI
+       cli
        mov     %rsp, %r15              /* AST changes stack, saved state */
        xorl    %ecx, %ecx              /* don't check if we're in the PFZ */
        jmp     EXT(return_from_trap)   /* and check again (rare) */
@@ -1154,8 +1158,6 @@ Entry(hndl_allintrs)
 
        CCALL1(interrupt, %r15)         /* call generic interrupt routine */
 
-       cli                             /* just in case we returned with intrs enabled */
-
        .globl  EXT(return_to_iret)
 LEXT(return_to_iret)                   /* (label for kdb_kintr and hardclock) */
 
@@ -1352,6 +1354,7 @@ Entry(hndl_syscall)
        TIME_TRAP_UENTRY
 
        movq    %gs:CPU_ACTIVE_THREAD,%rcx      /* get current thread     */
+       movl    $-1, TH_IOTIER_OVERRIDE(%rcx)   /* Reset IO tier override to -1 before handling syscall */
        movq    TH_TASK(%rcx),%rbx              /* point to current task  */
 
        /* Check for active vtimers in the current task */
@@ -1410,7 +1413,6 @@ Entry(hndl_mdep_scall64)
 
 Entry(hndl_diag_scall64)
        CCALL1(diagCall64, %r15)        // Call diagnostics
-       cli                             // Disable interruptions just in case
        test    %eax, %eax              // What kind of return is this?
        je      1f                      // - branch if bad (zero)
        jmp     EXT(return_to_user)     // Normal return, do not check asts...