ntdll: More compatible exception information for protection faults.

dlls/ntdll/signal_i386.c

@@ -484,7 +484,7 @@ static inline int get_trap_code( const SIGCONTEXT *sigcontext )
  *
  * Get the error code for a signal.
  */
-static inline int get_error_code( const SIGCONTEXT *sigcontext )
+static inline WORD get_error_code( const SIGCONTEXT *sigcontext )
 {
 #ifdef ERROR_sig
     return ERROR_sig(sigcontext);
@@ -794,6 +794,71 @@ inline static void restore_context( const CONTEXT *context, SIGCONTEXT *sigconte
 
 
 /***********************************************************************
+ *           is_privileged_instr
+ *
+ * Check if the fault location is a privileged instruction.
+ * Based on the instruction emulation code in dlls/kernel/instr.c.
+ */
+static inline int is_privileged_instr( CONTEXT86 *context )
+{
+    const BYTE *instr;
+    unsigned int prefix_count = 0;
+
+    if (!wine_ldt_is_system( context->SegCs )) return 0;
+    instr = (BYTE *)context->Eip;
+
+    for (;;) switch(*instr)
+    {
+    /* instruction prefixes */
+    case 0x2e:  /* %cs: */
+    case 0x36:  /* %ss: */
+    case 0x3e:  /* %ds: */
+    case 0x26:  /* %es: */
+    case 0x64:  /* %fs: */
+    case 0x65:  /* %gs: */
+    case 0x66:  /* opcode size */
+    case 0x67:  /* addr size */
+    case 0xf0:  /* lock */
+    case 0xf2:  /* repne */
+    case 0xf3:  /* repe */
+        if (++prefix_count >= 15) return 0;
+        instr++;
+        continue;
+
+    case 0x0f: /* extended instruction */
+        switch(instr[1])
+        {
+        case 0x20: /* mov crX, reg */
+        case 0x21: /* mov drX, reg */
+        case 0x22: /* mov reg, crX */
+        case 0x23: /* mov reg drX */
+            return 1;
+        }
+        return 0;
+    case 0x6c: /* insb (%dx) */
+    case 0x6d: /* insl (%dx) */
+    case 0x6e: /* outsb (%dx) */
+    case 0x6f: /* outsl (%dx) */
+    case 0xcd: /* int $xx */
+    case 0xe4: /* inb al,XX */
+    case 0xe5: /* in (e)ax,XX */
+    case 0xe6: /* outb XX,al */
+    case 0xe7: /* out XX,(e)ax */
+    case 0xec: /* inb (%dx),%al */
+    case 0xed: /* inl (%dx),%eax */
+    case 0xee: /* outb %al,(%dx) */
+    case 0xef: /* outl %eax,(%dx) */
+    case 0xf4: /* hlt */
+    case 0xfa: /* cli */
+    case 0xfb: /* sti */
+        return 1;
+    default:
+        return 0;
+    }
+}
+
+
+/***********************************************************************
  *           setup_exception
  *
  * Setup a proper stack frame for the raise function, and modify the
@@ -1063,8 +1128,17 @@ static HANDLER_DEF(segv_handler)
     case T_SEGNPFLT:  /* Segment not present exception */
     case T_PROTFLT:   /* General protection fault */
     case T_UNKNOWN:   /* Unknown fault code */
-        rec->ExceptionCode = get_error_code(HANDLER_CONTEXT) ? EXCEPTION_ACCESS_VIOLATION
-                                                             : EXCEPTION_PRIV_INSTRUCTION;
+        if (!get_error_code(HANDLER_CONTEXT) && is_privileged_instr( get_exception_context(rec) ))
+            rec->ExceptionCode = EXCEPTION_PRIV_INSTRUCTION;
+        else
+        {
+            WORD err = get_error_code(HANDLER_CONTEXT);
+            rec->ExceptionCode = EXCEPTION_ACCESS_VIOLATION;
+            rec->NumberParameters = 2;
+            rec->ExceptionInformation[0] = 0;
+            /* if error contains a LDT selector, use that as fault address */
+            rec->ExceptionInformation[1] = (err & 7) == 4 ? (err & ~7) : 0xffffffff;
+        }
         break;
     case T_PAGEFLT:  /* Page fault */
         rec->ExceptionCode = EXCEPTION_ACCESS_VIOLATION;

dlls/ntdll/tests/.gitignore

@@ -2,6 +2,7 @@ Makefile
 atom.ok
 env.ok
 error.ok
+exception.ok
 generated.ok
 info.ok
 large_int.ok

dlls/ntdll/tests/Makefile.in

@@ -9,6 +9,7 @@ CTESTS = \
 	atom.c \
 	env.c \
 	error.c \
+	exception.c \
 	generated.c \
 	info.c \
 	large_int.c \

dlls/ntdll/tests/exception.c

+/*
+ * Unit test suite for ntdll exceptions
+ *
+ * Copyright 2005 Alexandre Julliard
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#include <stdarg.h>
+
+#ifndef _WIN32_WINNT
+#define _WIN32_WINNT 0x500 /* For NTSTATUS */
+#endif
+
+#include "ntstatus.h"
+#define WIN32_NO_STATUS
+#include "windef.h"
+#include "winbase.h"
+#include "winnt.h"
+#include "winreg.h"
+#include "winternl.h"
+#include "excpt.h"
+#include "wine/test.h"
+
+#ifdef __i386__
+
+/* Test various instruction combinations that cause a protection fault on the i386,
+ * and check what the resulting exception looks like.
+ */
+
+static const struct exception
+{
+    BYTE     code[18];   /* asm code */
+    BYTE     offset;     /* offset of faulting instruction */
+    BYTE     length;     /* length of faulting instruction */
+    NTSTATUS status;     /* expected status code */
+    DWORD    nb_params;  /* expected number of parameters */
+    DWORD    params[4];  /* expected parameters */
+} exceptions[] =
+{
+    /* test some privileged instructions */
+    { { 0x6c, 0xc3 },  /* insb (%dx); ret */
+      0, 1, STATUS_PRIVILEGED_INSTRUCTION, 0 },
+    { { 0x6d, 0xc3 },  /* insl (%dx); ret */
+      0, 1, STATUS_PRIVILEGED_INSTRUCTION, 0 },
+    { { 0x6e, 0xc3 },  /* outsb (%dx); ret */
+      0, 1, STATUS_PRIVILEGED_INSTRUCTION, 0 },
+    { { 0x6f, 0xc3 },  /* outsl (%dx); ret */
+      0, 1, STATUS_PRIVILEGED_INSTRUCTION, 0 },
+    { { 0xe4, 0x11, 0xc3 },  /* inb $0x11,%al; ret */
+      0, 2, STATUS_PRIVILEGED_INSTRUCTION, 0 },
+    { { 0xe5, 0x11, 0xc3 },  /* inl $0x11,%eax; ret */
+      0, 2, STATUS_PRIVILEGED_INSTRUCTION, 0 },
+    { { 0xe6, 0x11, 0xc3 },  /* outb %al,$0x11; ret */
+      0, 2, STATUS_PRIVILEGED_INSTRUCTION, 0 },
+    { { 0xe7, 0x11, 0xc3 },  /* outl %eax,$0x11; ret */
+      0, 2, STATUS_PRIVILEGED_INSTRUCTION, 0 },
+    { { 0xed, 0xc3 },  /* inl (%dx),%eax; ret */
+      0, 1, STATUS_PRIVILEGED_INSTRUCTION, 0 },
+    { { 0xee, 0xc3 },  /* outb %al,(%dx); ret */
+      0, 1, STATUS_PRIVILEGED_INSTRUCTION, 0 },
+    { { 0xef, 0xc3 },  /* outl %eax,(%dx); ret */
+      0, 1, STATUS_PRIVILEGED_INSTRUCTION, 0 },
+    { { 0xf4, 0xc3 },  /* hlt; ret */
+      0, 1, STATUS_PRIVILEGED_INSTRUCTION, 0 },
+    { { 0xfa, 0xc3 },  /* cli; ret */
+      0, 1, STATUS_PRIVILEGED_INSTRUCTION, 0 },
+    { { 0xfb, 0xc3 },  /* sti; ret */
+      0, 1, STATUS_PRIVILEGED_INSTRUCTION, 0 },
+
+    /* test long jump to invalid selector */
+    { { 0xea, 0, 0, 0, 0, 0, 0, 0xc3 },  /* ljmp $0,$0; ret */
+      0, 7, STATUS_ACCESS_VIOLATION, 2, { 0, 0xffffffff } },
+
+    /* test iret to invalid selector */
+    { { 0x6a, 0x00, 0x6a, 0x00, 0x6a, 0x00, 0xcf, 0x83, 0xc4, 0x0c, 0xc3 },
+      /* pushl $0; pushl $0; pushl $0; iret; addl $12,%esp; ret */
+      6, 1, STATUS_ACCESS_VIOLATION, 2, { 0, 0xffffffff } },
+
+    /* test loading an invalid selector */
+    { { 0xb8, 0xef, 0xbe, 0x00, 0x00, 0x8e, 0xe8, 0xc3 },  /* mov $beef,%ax; mov %ax,%gs; ret */
+      5, 2, STATUS_ACCESS_VIOLATION, 2, { 0, 0xbee8 } },
+
+    /* test accessing a zero selector */
+    { { 0x06, 0x31, 0xc0, 0x8e, 0xc0, 0x26, 0xa1, 0, 0, 0, 0, 0x07, 0xc3 },
+          /* push %es; xor %eax,%eax; mov %ax,%es; mov %es:(0),%ax; pop %es */
+      5, 6, STATUS_ACCESS_VIOLATION, 2, { 0, 0xffffffff } },
+
+    /* test moving %cs -> %ss */
+    { { 0x0e, 0x17, 0x58, 0xc3 },  /* pushl %cs; popl %ss; popl %eax; ret */
+      1, 1, STATUS_ACCESS_VIOLATION, 2, { 0, 0xffffffff } },
+
+    /* test overlong instruction (limit is 16 bytes) */
+    { { 0x64,0x64,0x64,0x64,0x64,0x64,0x64,0x64,0x64,0x64,0x64,0x64,0x64,0x64,0x64,0xfa,0xc3 },
+      0, 16, STATUS_ACCESS_VIOLATION, 2, { 0, 0xffffffff } },
+    { { 0x64,0x64,0x64,0x64,0x64,0x64,0x64,0x64,0x64,0x64,0x64,0x64,0x64,0x64,0xfa,0xc3 },
+      0, 15, STATUS_PRIVILEGED_INSTRUCTION, 0 },
+
+    /* test invalid interrupt */
+    { { 0xcd, 0xff, 0xc3 },   /* int $0xff; ret */
+      0, 2, STATUS_ACCESS_VIOLATION, 2, { 0, 0xffffffff } },
+
+    /* test moves to/from Crx */
+    { { 0x0f, 0x20, 0xc0, 0xc3 },  /* movl %cr0,%eax; ret */
+      0, 3, STATUS_PRIVILEGED_INSTRUCTION, 0 },
+    { { 0x0f, 0x20, 0xe0, 0xc3 },  /* movl %cr4,%eax; ret */
+      0, 3, STATUS_PRIVILEGED_INSTRUCTION, 0 },
+    { { 0x0f, 0x22, 0xc0, 0xc3 },  /* movl %eax,%cr0; ret */
+      0, 3, STATUS_PRIVILEGED_INSTRUCTION, 0 },
+    { { 0x0f, 0x22, 0xe0, 0xc3 },  /* movl %eax,%cr4; ret */
+      0, 3, STATUS_PRIVILEGED_INSTRUCTION, 0 },
+
+    /* test moves to/from Drx */
+    { { 0x0f, 0x21, 0xc0, 0xc3 },  /* movl %dr0,%eax; ret */
+      0, 3, STATUS_PRIVILEGED_INSTRUCTION, 0 },
+    { { 0x0f, 0x21, 0xc8, 0xc3 },  /* movl %dr1,%eax; ret */
+      0, 3, STATUS_PRIVILEGED_INSTRUCTION, 0 },
+    { { 0x0f, 0x21, 0xf8, 0xc3 },  /* movl %dr7,%eax; ret */
+      0, 3, STATUS_PRIVILEGED_INSTRUCTION, 0 },
+    { { 0x0f, 0x23, 0xc0, 0xc3 },  /* movl %eax,%dr0; ret */
+      0, 3, STATUS_PRIVILEGED_INSTRUCTION, 0 },
+    { { 0x0f, 0x23, 0xc8, 0xc3 },  /* movl %eax,%dr1; ret */
+      0, 3, STATUS_PRIVILEGED_INSTRUCTION, 0 },
+    { { 0x0f, 0x23, 0xf8, 0xc3 },  /* movl %eax,%dr7; ret */
+      0, 3, STATUS_PRIVILEGED_INSTRUCTION, 0 },
+
+    /* test memory reads */
+    { { 0xa1, 0xfc, 0xff, 0xff, 0xff, 0xc3 },  /* movl 0xfffffffc,%eax; ret */
+      0, 5, STATUS_ACCESS_VIOLATION, 2, { 0, 0xfffffffc } },
+    { { 0xa1, 0xfd, 0xff, 0xff, 0xff, 0xc3 },  /* movl 0xfffffffd,%eax; ret */
+      0, 5, STATUS_ACCESS_VIOLATION, 2, { 0, 0xffffffff } },
+    { { 0xa1, 0xfe, 0xff, 0xff, 0xff, 0xc3 },  /* movl 0xfffffffe,%eax; ret */
+      0, 5, STATUS_ACCESS_VIOLATION, 2, { 0, 0xffffffff } },
+    { { 0xa1, 0xff, 0xff, 0xff, 0xff, 0xc3 },  /* movl 0xffffffff,%eax; ret */
+      0, 5, STATUS_ACCESS_VIOLATION, 2, { 0, 0xffffffff } },
+
+    /* test memory writes */
+    { { 0xa3, 0xfc, 0xff, 0xff, 0xff, 0xc3 },  /* movl %eax,0xfffffffc; ret */
+      0, 5, STATUS_ACCESS_VIOLATION, 2, { 1, 0xfffffffc } },
+    { { 0xa3, 0xfd, 0xff, 0xff, 0xff, 0xc3 },  /* movl %eax,0xfffffffd; ret */
+      0, 5, STATUS_ACCESS_VIOLATION, 2, { 0, 0xffffffff } },
+    { { 0xa3, 0xfe, 0xff, 0xff, 0xff, 0xc3 },  /* movl %eax,0xfffffffe; ret */
+      0, 5, STATUS_ACCESS_VIOLATION, 2, { 0, 0xffffffff } },
+    { { 0xa3, 0xff, 0xff, 0xff, 0xff, 0xc3 },  /* movl %eax,0xffffffff; ret */
+      0, 5, STATUS_ACCESS_VIOLATION, 2, { 0, 0xffffffff } },
+};
+
+static int got_exception;
+
+static DWORD handler( EXCEPTION_RECORD *rec, EXCEPTION_REGISTRATION_RECORD *frame,
+                      CONTEXT *context, EXCEPTION_REGISTRATION_RECORD **dispatcher )
+{
+    const struct exception *except = *(const struct exception **)(frame + 1);
+    unsigned int i, entry = except - exceptions;
+
+    got_exception++;
+    trace( "exception: %lx flags:%lx addr:%p\n",
+           rec->ExceptionCode, rec->ExceptionFlags, rec->ExceptionAddress );
+
+    ok( rec->ExceptionCode == except->status,
+        "%u: Wrong exception code %lx/%lx\n", entry, rec->ExceptionCode, except->status );
+    ok( rec->ExceptionAddress == except->code + except->offset,
+        "%u: Wrong exception address %p/%p\n", entry,
+        rec->ExceptionAddress, except->code + except->offset );
+
+    ok( rec->NumberParameters == except->nb_params,
+        "%u: Wrong number of parameters %lu/%lu\n", entry, rec->NumberParameters, except->nb_params );
+    for (i = 0; i < rec->NumberParameters; i++)
+        ok( rec->ExceptionInformation[i] == except->params[i],
+            "%u: Wrong parameter %d: %lx/%lx\n",
+            entry, i, rec->ExceptionInformation[i], except->params[i] );
+
+    /* don't handle exception if it's not the address we expected */
+    if (rec->ExceptionAddress != except->code + except->offset) return ExceptionContinueSearch;
+
+    context->Eip += except->length;
+    return ExceptionContinueExecution;
+}
+
+static void test_prot_fault(void)
+{
+    unsigned int i;
+    struct
+    {
+        EXCEPTION_REGISTRATION_RECORD frame;
+        const struct exception       *except;
+    } exc_frame;
+
+    exc_frame.frame.Handler = handler;
+    exc_frame.frame.Prev = NtCurrentTeb()->Tib.ExceptionList;
+    NtCurrentTeb()->Tib.ExceptionList = &exc_frame.frame;
+    for (i = 0; i < sizeof(exceptions)/sizeof(exceptions[0]); i++)
+    {
+        void (*func)(void) = (void *)exceptions[i].code;
+        exc_frame.except = &exceptions[i];
+        got_exception = 0;
+        func();
+        ok( got_exception == (exceptions[i].status != 0),
+            "%u: bad exception count %d\n", i, got_exception );
+    }
+    NtCurrentTeb()->Tib.ExceptionList = exc_frame.frame.Prev;
+}
+
+#endif  /* __i386__ */
+
+START_TEST(exception)
+{
+#ifdef __i386__
+    test_prot_fault();
+#endif
+}