Module Name: src
Committed By: maxv
Date: Thu Aug 31 09:33:19 UTC 2017
Modified Files:
src/sys/arch/amd64/amd64: amd64_trap.S
Log Message:
Reorder for clarity, and style.
To generate a diff of this commit:
cvs rdiff -u -r1.7 -r1.8 src/sys/arch/amd64/amd64/amd64_trap.S
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/arch/amd64/amd64/amd64_trap.S
diff -u src/sys/arch/amd64/amd64/amd64_trap.S:1.7 src/sys/arch/amd64/amd64/amd64_trap.S:1.8
--- src/sys/arch/amd64/amd64/amd64_trap.S:1.7 Fri Aug 18 14:52:19 2017
+++ src/sys/arch/amd64/amd64/amd64_trap.S Thu Aug 31 09:33:19 2017
@@ -1,11 +1,11 @@
-/* $NetBSD: amd64_trap.S,v 1.7 2017/08/18 14:52:19 maxv Exp $ */
+/* $NetBSD: amd64_trap.S,v 1.8 2017/08/31 09:33:19 maxv Exp $ */
-/*-
- * Copyright (c) 1998, 2007, 2008 The NetBSD Foundation, Inc.
+/*
+ * Copyright (c) 1998, 2007, 2008, 2017 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
- * by Charles M. Hannum and by Andrew Doran.
+ * by Charles M. Hannum, by Andrew Doran and by Maxime Villard.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
@@ -66,7 +66,7 @@
#if 0
#include <machine/asm.h>
-__KERNEL_RCSID(0, "$NetBSD: amd64_trap.S,v 1.7 2017/08/18 14:52:19 maxv Exp $");
+__KERNEL_RCSID(0, "$NetBSD: amd64_trap.S,v 1.8 2017/08/31 09:33:19 maxv Exp $");
#endif
/*
@@ -78,12 +78,12 @@ __KERNEL_RCSID(0, "$NetBSD: amd64_trap.S
* (possibly the next clock tick). Thus, we disable interrupt before checking,
* and only enable them again on the final `iret' or before calling the AST
* handler.
- */
+ */
/*****************************************************************************/
#ifdef XEN
-#define PRE_TRAP movq (%rsp),%rcx ; movq 8(%rsp),%r11 ; addq $0x10,%rsp
+#define PRE_TRAP movq (%rsp),%rcx ; movq 8(%rsp),%r11 ; addq $0x10,%rsp
#else
#define PRE_TRAP
#endif
@@ -214,7 +214,7 @@ IDTVEC(trap07)
INTRENTRY
#ifdef DIAGNOSTIC
movl CPUVAR(ILEVEL),%ebx
-#endif /* DIAGNOSTIC */
+#endif
movq %rsp,%rdi
call _C_LABEL(fpudna)
jmp .Lalltraps_checkusr
@@ -253,43 +253,7 @@ IDTVEC_END(trap0c)
IDTVEC(trap0d) /* #GP() General protection */
TRAP_NJ(T_PROTFLT)
-#ifdef check_swapgs
jmp check_swapgs
-#else
-/*
- * We need to worry about traps in kernel mode while the kernel %gs isn't
- * loaded. These are either faults on iretq during return to user or loads to
- * %gs.
- *
- * When such traps happen, we have CPL=0 and %gs=userland, and we must perform
- * an additional swapgs to get %gs=kernel.
- */
-check_swapgs:
- INTRENTRY_L(3f,1:)
-2:
- sti
- jmp calltrap
-3:
- /*
- * Trap in kernel mode.
- */
- /* Case 1: fault on iretq? */
- movq TF_RIP(%rsp),%rax
- cmpw $0xcf48,(%rax) /* Faulting instruction is iretq ? */
- jne 5f /* Jump if not */
- movq TF_RSP(%rsp),%rax /* Must read %rsp, may be a pad word */
- testb $SEL_UPL,8(%rax) /* Check %cs of outer iret frame */
- je 2b /* jump if iret was to kernel */
- jmp 1b /* to user - must restore %gs */
-5:
-
- /* Case 2: move to %gs? */
- movw (%rax),%ax
- andb $070,%ah /* mask mod/rm from mod/reg/rm */
- cmpw $0x8e+050*256,%ax /* Any move to %gs (reg 5) */
- jne 2b /* No - normal kernel fault */
- jmp 1b /* Yes - restore %gs */
-#endif
IDTVEC_END(trap0d)
IDTVEC(trap0e)
@@ -302,7 +266,7 @@ IDTVEC(trap0f)
INTRENTRY
#ifdef DIAGNOSTIC
movl CPUVAR(ILEVEL),%ebx
-#endif /* DIAGNOSTIC */
+#endif
jmp .Lalltraps_checkusr
IDTVEC_END(trap0f)
IDTVEC_END(intrspurious)
@@ -313,7 +277,7 @@ IDTVEC(trap10)
INTRENTRY
#ifdef DIAGNOSTIC
movl CPUVAR(ILEVEL),%ebx
-#endif /* DIAGNOSTIC */
+#endif
movq %rsp,%rdi
call _C_LABEL(fputrap)
jmp .Lalltraps_checkusr
@@ -380,9 +344,9 @@ IDTVEC_END(exceptions)
/*
* trap() calls here when it detects a fault in INTRFASTEXIT (loading the
- * segment registers or during the iret itself).
- * The address of the (possibly reconstructed) user trap frame is
- * passed as an argument.
+ * segment registers or during the iret itself). The address of the (possibly
+ * reconstructed) user trap frame is passed as an argument.
+ *
* Typically the code will have raised a SIGSEGV which will be actioned
* by the code below.
*/
@@ -392,10 +356,47 @@ LABEL(trap_return_fault_return)
#ifdef DIAGNOSTIC
/* We can't recover the saved %rbx, so suppress warning */
movl CPUVAR(ILEVEL),%ebx
-#endif /* DIAGNOSTIC */
+#endif
jmp .Lalltraps_checkusr
END(trap_return_fault_return)
+#ifndef check_swapgs
+/*
+ * We need to worry about traps in kernel mode while the kernel %gs isn't
+ * loaded. These are either faults on iretq during return to user or loads to
+ * %gs.
+ *
+ * When such traps happen, we have CPL=0 and %gs=userland, and we must perform
+ * an additional swapgs to get %gs=kernel.
+ */
+NENTRY(check_swapgs)
+ INTRENTRY_L(3f,1:)
+2:
+ sti
+ jmp calltrap
+3:
+ /*
+ * Trap in kernel mode.
+ */
+ /* Case 1: fault on iretq? */
+ movq TF_RIP(%rsp),%rax
+ cmpw $0xcf48,(%rax) /* Faulting instruction is iretq ? */
+ jne 5f /* Jump if not */
+ movq TF_RSP(%rsp),%rax /* Must read %rsp, may be a pad word */
+ testb $SEL_UPL,8(%rax) /* Check %cs of outer iret frame */
+ je 2b /* jump if iret was to kernel */
+ jmp 1b /* to user - must restore %gs */
+5:
+
+ /* Case 2: move to %gs? */
+ movw (%rax),%ax
+ andb $070,%ah /* mask mod/rm from mod/reg/rm */
+ cmpw $0x8e+050*256,%ax /* Any move to %gs (reg 5) */
+ jne 2b /* No - normal kernel fault */
+ jmp 1b /* Yes - restore %gs */
+END(check_swapgs)
+#endif
+
/*
* All traps go through here. Call the generic trap handler, and
* check for ASTs afterwards.
@@ -407,13 +408,15 @@ NENTRY(alltraps)
calltrap:
#ifdef DIAGNOSTIC
movl CPUVAR(ILEVEL),%ebx
-#endif /* DIAGNOSTIC */
+#endif
movq %rsp,%rdi
incq CPUVAR(NTRAP)
call _C_LABEL(trap)
+
.Lalltraps_checkusr:
testb $SEL_RPL,TF_CS(%rsp)
jz 6f
+
.Lalltraps_checkast:
movq CPUVAR(CURLWP),%r14
/* Check for ASTs on exit to user mode. */
@@ -429,13 +432,21 @@ calltrap:
jmp .Lalltraps_checkast /* re-check ASTs */
3: CHECK_DEFERRED_SWITCH
jnz 9f
-#ifndef DIAGNOSTIC
-6: INTRFASTEXIT
-#else /* DIAGNOSTIC */
-6: cmpl CPUVAR(ILEVEL),%ebx
- jne 3f
+
+6:
+#ifdef DIAGNOSTIC
+ cmpl CPUVAR(ILEVEL),%ebx
+ jne .Lspl_error
+#endif
INTRFASTEXIT
-3: STI(si)
+
+9: STI(si)
+ call _C_LABEL(do_pmap_load)
+ jmp .Lalltraps_checkast /* re-check ASTs */
+
+#ifdef DIAGNOSTIC
+.Lspl_error:
+ STI(si)
movabsq $4f,%rdi
movl CPUVAR(ILEVEL),%esi
movl %ebx,%edx
@@ -445,8 +456,6 @@ calltrap:
call _C_LABEL(spllower)
jmp .Lalltraps_checkast
4: .asciz "WARNING: SPL NOT LOWERED ON TRAP EXIT %x %x\n"
-#endif /* DIAGNOSTIC */
-9: STI(si)
- call _C_LABEL(do_pmap_load)
- jmp .Lalltraps_checkast /* re-check ASTs */
+#endif
END(alltraps)
+
