--- /dev/null
+/* $Id$
+ * UNIX signal handling for processor emulation for support of ntoskrnl of libcaptive
+ * Copyright (C) 2002 Jan Kratochvil <project-captive@jankratochvil.net>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; exactly version 2 of June 1991 is required
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+
+#define _GNU_SOURCE 1 /* for sys/ucontext.h for REG_* */
+
+#include "config.h"
+
+#include "captive/signal.h" /* self */
+#include <glib/gtypes.h>
+#include <glib/gmessages.h>
+#include <signal.h>
+#include "captive/macros.h"
+#include <sys/ucontext.h> /* for struct ucontext */
+#include "captive/mm.h" /* for captive_mmap_map_get() */
+#include <sys/mman.h>
+#include "reactos/internal/mm.h" /* for PAGE_SIZE */
+
+
+static greg_t val_exceptionstack_top;
+
+static gboolean instr_mov_greg_to_fsmem(int greg,const void *fsmem,struct ucontext *ucontext)
+{
+ if (fsmem==0x00000000) { /* exception stack top pointer */
+ /* moving from %esp is required to pass! */
+ val_exceptionstack_top=ucontext->uc_mcontext.gregs[greg];
+ return TRUE;
+ }
+ g_return_val_if_reached(FALSE);
+}
+
+static gboolean instr_mov_fsmem_to_greg(const void *fsmem,int greg,struct ucontext *ucontext)
+{
+ if (fsmem==0x00000000) { /* exception stack top pointer */
+ /* moving to %esp is required to pass! */
+ ucontext->uc_mcontext.gregs[greg]=val_exceptionstack_top;
+ return TRUE;
+ }
+ g_return_val_if_reached(FALSE);
+}
+
+static int op_regcode_to_greg(guint8 regcode)
+{
+ switch (regcode) {
+ case 0x00: return REG_EAX;
+ case 0x01: return REG_ECX;
+ case 0x02: return REG_EDX;
+ case 0x03: return REG_EBX;
+ case 0x04: return REG_ESP;
+ case 0x05: return REG_EBP;
+ case 0x06: return REG_ESI;
+ case 0x07: return REG_EDI;
+ }
+ g_return_val_if_reached(REG_EAX);
+}
+
+static void sigaction_SIGSEGV(int signo,siginfo_t *siginfo,struct ucontext *ucontext)
+{
+const guint8 *reg_eip;
+const void *reg_eip_aligned;
+
+ g_return_if_fail(signo==SIGSEGV);
+ g_return_if_fail(siginfo->si_signo==SIGSEGV);
+ /* siginfo->si_code is weird, seen to have value 128 */
+
+ reg_eip=(void *)ucontext->uc_mcontext.gregs[REG_EIP];
+
+ /* 'reg_eip' is not yet PAGE_SIZE-aligned but we need the aligned ptr for captive_mmap_map_get().
+ * glib NOTE: YOU MAY NOT STORE POINTERS IN INTEGERS.
+ */
+ reg_eip_aligned=(const void *)(((char *)reg_eip)-(GPOINTER_TO_UINT(reg_eip)&(PAGE_SIZE-1)));
+ g_assert(reg_eip_aligned!=NULL);
+ g_return_if_fail(!(captive_mmap_map_get(reg_eip_aligned)&PROT_EXEC));
+
+ /* all instruction notation comments are written in AT&T 'instr src,dest' syntax! */
+ if (*reg_eip==0x64) { /* prefix '%fs:' */
+ reg_eip++;
+ if (*reg_eip==0xA3) { /* 'mov %eax,%fs:{reg_eip[1..4]}' */
+ reg_eip++;
+ if (instr_mov_greg_to_fsmem(REG_EAX,*(const void **)reg_eip,ucontext)) {
+ reg_eip+=4;
+ goto ok;
+ }
+ g_assert_not_reached();
+ }
+ if (*reg_eip==0x89) { /* prefix 0x89 */
+ reg_eip++;
+ if ((*reg_eip & ~0x38)==0x05) { /* 'mov %{op_regcode_to_greg(*reg_eip[b3..b5])},%fs:{reg_eip[1..4]} */
+ reg_eip++;
+ if (instr_mov_greg_to_fsmem(op_regcode_to_greg(reg_eip[-1]>>3U),*(const void **)reg_eip,ucontext)) {
+ reg_eip+=4;
+ goto ok;
+ }
+ g_assert_not_reached();
+ }
+ g_assert_not_reached();
+ }
+ if (*reg_eip==0xA1) { /* 'mov %fs:{reg_eip[1..4]},%eax' */
+ reg_eip++;
+ if (instr_mov_fsmem_to_greg(*(const void **)reg_eip,REG_EAX,ucontext)) {
+ reg_eip+=4;
+ goto ok;
+ }
+ g_assert_not_reached();
+ }
+ if (*reg_eip==0x8B) { /* prefix 0x8B */
+ reg_eip++;
+ if ((*reg_eip & ~0x38)==0x05) { /* 'mov %fs:{reg_eip[1..4]},%{op_regcode_to_greg(*reg_eip[b3..b5])} */
+ reg_eip++;
+ if (instr_mov_fsmem_to_greg(*(const void **)reg_eip,op_regcode_to_greg(reg_eip[-1]>>3U),ucontext)) {
+ reg_eip+=4;
+ goto ok;
+ }
+ g_assert_not_reached();
+ }
+ g_assert_not_reached();
+ }
+ g_assert_not_reached();
+ }
+ g_assert_not_reached();
+
+ok:
+ ucontext->uc_mcontext.gregs[REG_EIP]=(greg_t)reg_eip;
+ /* success */
+}
+
+/**
+ * captive_signal_init:
+ *
+ * Initialize UNIX signal handling to be able to emulate foreign W32
+ * instructions. These instructions must be located inside address
+ * space of foreign W32 binary code which is identified by successful
+ * call to captive_mmap_map_get() returning #PROT_EXEC bit set.
+ * This bit should be set from MmAllocateSection() called from
+ * ntoskrnl/ldr/loader.c/LdrPEProcessModule().
+ *
+ * Currently emulated set is the access to %fs register offset %0
+ * where the exception stack top pointer is located.
+ */
+gboolean captive_signal_init(void)
+{
+gint errint;
+struct sigaction sigaction_struct;
+sigset_t sigset;
+
+ CAPTIVE_MEMZERO(&sigaction_struct); /* this structure may have unpredictable fields */
+
+ /* Init 'sigaction_struct.sa_mask'. */
+ errint=sigemptyset(&sigaction_struct.sa_mask);
+ g_return_val_if_fail(errint==0,FALSE);
+ errint=sigaddset(&sigaction_struct.sa_mask,SIGSEGV);
+ g_return_val_if_fail(errint==0,FALSE);
+
+ /* Set the signal sigaction handler. */
+ sigaction_struct.sa_sigaction=(void (*)(int,siginfo_t *,void *))sigaction_SIGSEGV;
+ sigaction_struct.sa_flags=0
+ |SA_SIGINFO; /* Use 'sa_sigaction' (not 'sa_handler') */
+ errint=sigaction(SIGSEGV,
+ &sigaction_struct, /* act */
+ NULL); /* oldact */
+ g_return_val_if_fail(errint==0,FALSE);
+
+ /* Enable SIGSEGV signal (should be default). */
+ errint=sigemptyset(&sigset);
+ g_return_val_if_fail(errint==0,FALSE);
+ errint=sigaddset(&sigset,SIGSEGV);
+ g_return_val_if_fail(errint==0,FALSE);
+ errint=sigprocmask(SIG_UNBLOCK,
+ &sigset, /* set */
+ NULL); /* oldset */
+ g_return_val_if_fail(errint==0,FALSE);
+
+ return TRUE;
+}
git://git.jankratochvil.net / captive.git / commitdiff