Module Name: src
Committed By: maxv
Date: Sun Sep 3 08:52:18 UTC 2017
Modified Files:
src/sys/arch/amd64/amd64: amd64_trap.S trap.c
src/sys/arch/amd64/conf: ALL
Log Message:
Remove useless debug code, and split trap() into smaller functions, easier
to understand. NMIs take another, faster path now. No functional change
beyond that.
To generate a diff of this commit:
cvs rdiff -u -r1.9 -r1.10 src/sys/arch/amd64/amd64/amd64_trap.S
cvs rdiff -u -r1.96 -r1.97 src/sys/arch/amd64/amd64/trap.c
cvs rdiff -u -r1.68 -r1.69 src/sys/arch/amd64/conf/ALL
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:1.9 src/sys/arch/amd64/amd64/amd64_trap.S:1.10
--- src/sys/arch/amd64/amd64/amd64_trap.S:1.9 Thu Aug 31 10:30:58 2017
+++ src/sys/arch/amd64/amd64/amd64_trap.S Sun Sep 3 08:52:18 2017
@@ -1,4 +1,4 @@
-/* $NetBSD: amd64_trap.S,v 1.9 2017/08/31 10:30:58 maxv Exp $ */
+/* $NetBSD: amd64_trap.S,v 1.10 2017/09/03 08:52:18 maxv Exp $ */
/*
* Copyright (c) 1998, 2007, 2008, 2017 The NetBSD Foundation, Inc.
@@ -66,7 +66,7 @@
#if 0
#include <machine/asm.h>
-__KERNEL_RCSID(0, "$NetBSD: amd64_trap.S,v 1.9 2017/08/31 10:30:58 maxv Exp $");
+__KERNEL_RCSID(0, "$NetBSD: amd64_trap.S,v 1.10 2017/09/03 08:52:18 maxv Exp $");
#endif
/*
@@ -135,7 +135,7 @@ IDTVEC(trap02)
swapgs
movq %rsp,%rdi
incq CPUVAR(NTRAP)
- call _C_LABEL(trap)
+ call _C_LABEL(nmitrap)
swapgs
jmp nmileave
Index: src/sys/arch/amd64/amd64/trap.c
diff -u src/sys/arch/amd64/amd64/trap.c:1.96 src/sys/arch/amd64/amd64/trap.c:1.97
--- src/sys/arch/amd64/amd64/trap.c:1.96 Mon Apr 24 17:03:43 2017
+++ src/sys/arch/amd64/amd64/trap.c Sun Sep 3 08:52:18 2017
@@ -1,11 +1,11 @@
-/* $NetBSD: trap.c,v 1.96 2017/04/24 17:03:43 chs Exp $ */
+/* $NetBSD: trap.c,v 1.97 2017/09/03 08:52:18 maxv Exp $ */
-/*-
- * Copyright (c) 1998, 2000 The NetBSD Foundation, Inc.
+/*
+ * Copyright (c) 1998, 2000, 2017 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
- * by Charles M. Hannum.
+ * by Charles M. Hannum, and by Maxime Villard.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
@@ -29,7 +29,7 @@
* POSSIBILITY OF SUCH DAMAGE.
*/
-/*-
+/*
* Copyright (c) 1990 The Regents of the University of California.
* All rights reserved.
*
@@ -63,12 +63,8 @@
* @(#)trap.c 7.4 (Berkeley) 5/13/91
*/
-/*
- * 386 Trap and System call handling
- */
-
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: trap.c,v 1.96 2017/04/24 17:03:43 chs Exp $");
+__KERNEL_RCSID(0, "$NetBSD: trap.c,v 1.97 2017/09/03 08:52:18 maxv Exp $");
#include "opt_ddb.h"
#include "opt_kgdb.h"
@@ -126,6 +122,7 @@ dtrace_trap_func_t dtrace_trap_func = NU
dtrace_doubletrap_func_t dtrace_doubletrap_func = NULL;
#endif
+void nmitrap(struct trapframe *);
void trap(struct trapframe *);
void trap_return_fault_return(struct trapframe *) __dead;
@@ -154,16 +151,8 @@ const char * const trap_type[] = {
};
int trap_types = __arraycount(trap_type);
-#ifdef DEBUG
-int trapdebug = 0;
-#endif
-
#define IDTVEC(name) __CONCAT(X, name)
-#ifdef TRAP_SIGDEBUG
-static void frame_dump(struct trapframe *, struct pcb *);
-#endif
-
static void *
onfault_handler(const struct pcb *pcb, const struct trapframe *tf)
{
@@ -210,6 +199,115 @@ trap_print(const struct trapframe *frame
l, l->l_proc->p_pid, l->l_lid, KSTACK_LOWEST_ADDR(l));
}
+void
+nmitrap(struct trapframe *frame)
+{
+ const int type = T_NMI;
+
+ if (nmi_dispatch(frame))
+ return;
+ /* NMI can be hooked up to a pushbutton for debugging */
+ if (kgdb_trap(type, frame))
+ return;
+ if (kdb_trap(type, 0, frame))
+ return;
+ /* machine/parity/power fail/"kitchen sink" faults */
+
+ x86_nmi();
+}
+
+/*
+ * Did we receive in kernel mode a trap that ought to be considered as a user
+ * trap? If this function returns, the answer is no.
+ *
+ * Such traps can be triggered when the kernel fails to return to userland,
+ * because of incorrect segment registers.
+ */
+#ifndef Xen
+static void trap_user_kernelmode(struct trapframe *, int, lwp_t *, proc_t *);
+
+static void
+trap_user_kernelmode(struct trapframe *frame, int type, lwp_t *l, proc_t *p)
+{
+ struct trapframe *vframe;
+ ksiginfo_t ksi;
+
+ if (frame->tf_rip == 0) {
+ /*
+ * Assume that if we jumped to null we probably did it via a
+ * null function pointer, so print the return address.
+ */
+ printf("kernel jumped to null; return addr was %p\n",
+ *(void **)frame->tf_rsp);
+ return;
+ }
+
+ KSI_INIT_TRAP(&ksi);
+ ksi.ksi_signo = SIGSEGV;
+ ksi.ksi_code = SEGV_ACCERR;
+ ksi.ksi_trap = type;
+
+ /*
+ * Get %rsp value before fault - there may be a pad word below the
+ * trap frame.
+ */
+ vframe = (void *)frame->tf_rsp;
+
+ switch (*(uint16_t *)frame->tf_rip) {
+ case 0xcf48: /* iretq */
+ /*
+ * The 'iretq' instruction faulted, so we have the
+ * 'user' registers saved after the kernel
+ * %rip:%cs:%fl:%rsp:%ss of the iret, and below that
+ * the user %rip:%cs:%fl:%rsp:%ss the 'iret' was
+ * processing.
+ * We must copy the user register back over the
+ * kernel fault frame to generate a normal stack
+ * frame (eg for sending a SIGSEGV).
+ */
+ vframe = (void *)((char *)vframe
+ - offsetof(struct trapframe, tf_rip));
+ memmove(vframe, frame, offsetof(struct trapframe, tf_rip));
+ /* Set the faulting address to the user %rip */
+ ksi.ksi_addr = (void *)vframe->tf_rip;
+ break;
+
+ case 0x848e: /* mov 0xa8(%rsp),%es (8e 84 24 a8 00 00 00) */
+ case 0x9c8e: /* mov 0xb0(%rsp),%ds (8e 9c 24 b0 00 00 00) */
+#ifdef USER_LDT
+ case 0xa48e: /* mov 0xa0(%rsp),%fs (8e a4 24 a0 00 00 00) */
+ case 0xac8e: /* mov 0x98(%rsp),%gs (8e ac 24 98 00 00 00) */
+#endif
+ /*
+ * We faulted loading one of the user segment registers.
+ * The stack frame containing the user registers is
+ * still valid and pointed to by tf_rsp.
+ */
+ if (KERNELMODE(vframe->tf_cs, vframe->tf_eflags))
+ return;
+ /* There is no valid address for the fault */
+ break;
+
+ default:
+ return;
+ }
+
+ /* XXX: worry about on-stack trampolines for nested handlers?? */
+ /* Save outer frame for any signal return */
+ l->l_md.md_regs = vframe;
+ (*p->p_emul->e_trapsignal)(l, &ksi);
+ /* Return to user by reloading the user frame */
+ trap_return_fault_return(vframe);
+ /* NOTREACHED */
+}
+#else
+/*
+ * XXX: there has to be an equivalent 'problem' but I (dsl) don't know exactly
+ * what happens! For now panic the kernel.
+ */
+#define trap_user_kernelmode(frame, type, l, p) /* NOTHING */
+#endif
+
/*
* trap(frame): exception, fault, and trap interface to BSD kernel.
*
@@ -231,9 +329,6 @@ trap(struct trapframe *frame)
extern char fusuintrfailure[], kcopy_fault[];
extern char IDTVEC(osyscall)[];
extern char IDTVEC(syscall32)[];
-#ifndef XEN
- struct trapframe *vframe;
-#endif
ksiginfo_t ksi;
void *onfault;
int type, error;
@@ -252,12 +347,7 @@ trap(struct trapframe *frame)
}
type = frame->tf_trapno;
-#ifdef DEBUG
- if (trapdebug) {
- trap_print(frame, l);
- }
-#endif
- if (type != T_NMI && !KERNELMODE(frame->tf_cs, frame->tf_rflags)) {
+ if (!KERNELMODE(frame->tf_cs, frame->tf_rflags)) {
type |= T_USER;
l->l_md.md_regs = frame;
LWP_CACHE_CREDS(l, p);
@@ -322,92 +412,9 @@ copyfault:
return;
}
- /*
- * Check for failure during return to user mode.
- * This can happen loading invalid values into the segment
- * registers, or during the 'iret' itself.
- *
- * We do this by looking at the instruction we faulted on.
- * The specific instructions we recognize only happen when
- * returning from a trap, syscall, or interrupt.
- */
-
kernelfault:
-#ifdef XEN
- /*
- * XXX: there has to be an equivalent 'problem'
- * but I (dsl) don't know exactly what happens!
- * For now panic the kernel.
- */
+ trap_user_kernelmode(frame, type, l, p);
goto we_re_toast;
-#else
- KSI_INIT_TRAP(&ksi);
- ksi.ksi_signo = SIGSEGV;
- ksi.ksi_code = SEGV_ACCERR;
- ksi.ksi_trap = type;
-
- /* Get %rsp value before fault - there may be a pad word
- * below the trap frame. */
- vframe = (void *)frame->tf_rsp;
- if (frame->tf_rip == 0) {
- /*
- * Assume that if we jumped to null we
- * probably did it via a null function
- * pointer, so print the return address.
- */
- printf("kernel jumped to null; return addr was %p\n",
- *(void **)frame->tf_rsp);
- goto we_re_toast;
- }
- switch (*(uint16_t *)frame->tf_rip) {
- case 0xcf48: /* iretq */
- /*
- * The 'iretq' instruction faulted, so we have the
- * 'user' registers saved after the kernel
- * %rip:%cs:%fl:%rsp:%ss of the iret, and below that
- * the user %rip:%cs:%fl:%rsp:%ss the 'iret' was
- * processing.
- * We must copy the user register back over the
- * kernel fault frame to generate a normal stack
- * frame (eg for sending a SIGSEGV).
- */
- vframe = (void *)((char *)vframe
- - offsetof(struct trapframe, tf_rip));
- memmove(vframe, frame,
- offsetof(struct trapframe, tf_rip));
- /* Set the faulting address to the user %eip */
- ksi.ksi_addr = (void *)vframe->tf_rip;
- break;
- case 0x848e: /* mov 0xa8(%rsp),%es (8e 84 24 a8 00 00 00) */
- case 0x9c8e: /* mov 0xb0(%rsp),%ds (8e 9c 24 b0 00 00 00) */
-#ifdef USER_LDT
- case 0xa48e: /* mov 0xa0(%rsp),%fs (8e a4 24 a0 00 00 00) */
- case 0xac8e: /* mov 0x98(%rsp),%gs (8e ac 24 98 00 00 00) */
-#endif
- /*
- * We faulted loading one of the user segment registers.
- * The stack frame containing the user registers is
- * still valid and pointed to by tf_rsp.
- * Maybe we should check the iretq follows.
- */
- if (KERNELMODE(vframe->tf_cs, vframe->tf_eflags))
- goto we_re_toast;
- /* There is no valid address for the fault */
- break;
-
- default:
- goto we_re_toast;
- }
-
- /* XXX: worry about on-stack trampolines for nested
- * handlers?? */
- /* Save outer frame for any signal return */
- l->l_md.md_regs = vframe;
- (*p->p_emul->e_trapsignal)(l, &ksi);
- /* Return to user by reloading the user frame */
- trap_return_fault_return(vframe);
- /* NOTREACHED */
-#endif
case T_PROTFLT|T_USER: /* protection fault */
#if defined(COMPAT_NETBSD32) && defined(COMPAT_10)
@@ -435,11 +442,6 @@ kernelfault:
case T_SEGNPFLT|T_USER:
case T_STKFLT|T_USER:
case T_ALIGNFLT|T_USER:
-#ifdef TRAP_SIGDEBUG
- printf("pid %d.%d (%s): BUS/SEGV (%#x) at rip %#lx addr %#lx\n",
- p->p_pid, l->l_lid, p->p_comm, type, frame->tf_rip, rcr2());
- frame_dump(frame, pcb);
-#endif
KSI_INIT_TRAP(&ksi);
ksi.ksi_trap = type & ~T_USER;
ksi.ksi_addr = (void *)rcr2();
@@ -467,13 +469,8 @@ kernelfault:
}
goto trapsignal;
- case T_PRIVINFLT|T_USER: /* privileged instruction fault */
- case T_FPOPFLT|T_USER: /* coprocessor operand fault */
-#ifdef TRAP_SIGDEBUG
- printf("pid %d.%d (%s): ILL at rip %#lx addr %#lx\n",
- p->p_pid, l->l_lid, p->p_comm, frame->tf_rip, rcr2());
- frame_dump(frame, pcb);
-#endif
+ case T_PRIVINFLT|T_USER:
+ case T_FPOPFLT|T_USER:
KSI_INIT_TRAP(&ksi);
ksi.ksi_signo = SIGILL;
ksi.ksi_trap = type & ~T_USER;
@@ -557,7 +554,7 @@ kernelfault:
goto faultcommon;
- case T_PAGEFLT|T_USER: { /* page fault */
+ case T_PAGEFLT|T_USER: {
register vaddr_t va;
register struct vmspace *vm;
register struct vm_map *map;
@@ -693,13 +690,6 @@ faultcommon:
break;
}
-#ifdef TRAP_SIGDEBUG
- printf("pid %d.%d (%s): signal %d at rip %#lx addr %#lx "
- "error %d trap %d cr2 %p\n", p->p_pid, l->l_lid, p->p_comm,
- ksi.ksi_signo, frame->tf_rip, va, error, ksi.ksi_trap,
- ksi.ksi_addr);
- frame_dump(frame, pcb);
-#endif
(*p->p_emul->e_trapsignal)(l, &ksi);
break;
}
@@ -726,12 +716,11 @@ faultcommon:
}
goto we_re_toast;
- case T_BPTFLT|T_USER: /* bpt instruction fault */
- case T_TRCTRAP|T_USER: /* trace trap */
+ case T_BPTFLT|T_USER:
+ case T_TRCTRAP|T_USER:
/*
* Don't go single-stepping into a RAS.
*/
-
if (p->p_raslist == NULL ||
(ras_lookup(p, (void *)frame->tf_rip) == (void *)-1)) {
KSI_INIT_TRAP(&ksi);
@@ -747,19 +736,6 @@ faultcommon:
(*p->p_emul->e_trapsignal)(l, &ksi);
}
break;
-
- case T_NMI:
- if (nmi_dispatch(frame))
- return;
- /* NMI can be hooked up to a pushbutton for debugging */
- if (kgdb_trap(type, frame))
- return;
- if (kdb_trap(type, 0, frame))
- return;
- /* machine/parity/power fail/"kitchen sink" faults */
-
- x86_nmi();
- return;
}
if ((type & T_USER) == 0)
@@ -772,7 +748,7 @@ trapsignal:
userret(l);
}
-/*
+/*
* startlwp: start of a new LWP.
*/
void
@@ -789,37 +765,3 @@ startlwp(void *arg)
userret(l);
}
-#ifdef TRAP_SIGDEBUG
-void
-frame_dump(struct trapframe *tf, struct pcb *pcb)
-{
- int i;
- unsigned long *p;
-
- printf("trapframe %p\n", tf);
- printf("rip 0x%016lx rsp 0x%016lx rfl 0x%016lx\n",
- tf->tf_rip, tf->tf_rsp, tf->tf_rflags);
- printf("rdi 0x%016lx rsi 0x%016lx rdx 0x%016lx\n",
- tf->tf_rdi, tf->tf_rsi, tf->tf_rdx);
- printf("rcx 0x%016lx r8 0x%016lx r9 0x%016lx\n",
- tf->tf_rcx, tf->tf_r8, tf->tf_r9);
- printf("r10 0x%016lx r11 0x%016lx r12 0x%016lx\n",
- tf->tf_r10, tf->tf_r11, tf->tf_r12);
- printf("r13 0x%016lx r14 0x%016lx r15 0x%016lx\n",
- tf->tf_r13, tf->tf_r14, tf->tf_r15);
- printf("rbp 0x%016lx rbx 0x%016lx rax 0x%016lx\n",
- tf->tf_rbp, tf->tf_rbx, tf->tf_rax);
- printf("cs 0x%04lx ds 0x%04lx es 0x%04lx "
- "fs 0x%04lx gs 0x%04lx ss 0x%04lx\n",
- tf->tf_cs & 0xffff, tf->tf_ds & 0xffff, tf->tf_es & 0xffff,
- tf->tf_fs & 0xffff, tf->tf_gs & 0xffff, tf->tf_ss & 0xffff);
- printf("fsbase 0x%016lx gsbase 0x%016lx\n",
- pcb->pcb_fs, pcb->pcb_gs);
- printf("\n");
- printf("Stack dump:\n");
- for (i = 0, p = (unsigned long *) tf; i < 20; i ++, p += 4)
- printf(" 0x%.16lx 0x%.16lx 0x%.16lx 0x%.16lx\n",
- p[0], p[1], p[2], p[3]);
- printf("\n");
-}
-#endif
Index: src/sys/arch/amd64/conf/ALL
diff -u src/sys/arch/amd64/conf/ALL:1.68 src/sys/arch/amd64/conf/ALL:1.69
--- src/sys/arch/amd64/conf/ALL:1.68 Wed Aug 30 15:44:01 2017
+++ src/sys/arch/amd64/conf/ALL Sun Sep 3 08:52:18 2017
@@ -1,4 +1,4 @@
-# $NetBSD: ALL,v 1.68 2017/08/30 15:44:01 maxv Exp $
+# $NetBSD: ALL,v 1.69 2017/09/03 08:52:18 maxv Exp $
# From NetBSD: GENERIC,v 1.787 2006/10/01 18:37:54 bouyer Exp
#
# ALL machine description file
@@ -17,7 +17,7 @@ include "arch/amd64/conf/std.amd64"
options INCLUDE_CONFIG_FILE # embed config file in kernel binary
-#ident "ALL-$Revision: 1.68 $"
+#ident "ALL-$Revision: 1.69 $"
maxusers 64 # estimated number of users
@@ -2273,7 +2273,6 @@ options TLP_DEBUG
options TP_DEBUG
options TRACE_DEBUG
options TRAPDEBUG
-options TRAP_SIGDEBUG
options TRISADEBUG
options TRM_DEBUG
options TROPICDEBUG
