ntdll: Support x86_64 syscall emulation.

The patch assigns the range of syscall numbers which does not
overlap with native syscalls and assumes these numbers are
used in the applications (i. e., that the applications
get the number from syscall thunks). Linux specific Seccomp
is used for trapping syscalls.

configure

@@ -7436,6 +7436,7 @@ for ac_header in \
 	linux/joystick.h \
 	linux/major.h \
 	linux/param.h \
+	linux/seccomp.h \
 	linux/serial.h \
 	linux/types.h \
 	linux/ucdrom.h \

configure.ac

@@ -474,6 +474,7 @@ AC_CHECK_HEADERS(\
 	linux/joystick.h \
 	linux/major.h \
 	linux/param.h \
+	linux/seccomp.h \
 	linux/serial.h \
 	linux/types.h \
 	linux/ucdrom.h \

dlls/ntdll/signal_x86_64.c

@@ -24,6 +24,7 @@
 #include "wine/port.h"
 
 #include <assert.h>
+#include <errno.h>
 #include <signal.h>
 #include <stdlib.h>
 #include <stdarg.h>
@@ -59,6 +60,13 @@
 # include <mach/mach.h>
 #endif
 
+#if defined(HAVE_LINUX_FILTER_H) && defined(HAVE_LINUX_SECCOMP_H) && defined(HAVE_SYS_PRCTL_H)
+#define HAVE_SECCOMP 1
+# include <linux/filter.h>
+# include <linux/seccomp.h>
+# include <sys/prctl.h>
+#endif
+
 #define NONAMELESSUNION
 #define NONAMELESSSTRUCT
 #include "ntstatus.h"
@@ -3096,6 +3104,38 @@ static void usr1_handler( int signal, siginfo_t *siginfo, void *ucontext )
     restore_context( &context, ucontext );
 }
 
+extern unsigned int __wine_nb_syscalls;
+
+#ifdef HAVE_SECCOMP
+static void sigsys_handler( int signal, siginfo_t *siginfo, void *sigcontext )
+{
+    unsigned int thunk_ret_offset;
+    ucontext_t *ctx = sigcontext;
+    unsigned int syscall_nr;
+    void ***rsp;
+
+    WARN("SIGSYS, rax %#llx.\n", ctx->uc_mcontext.gregs[REG_RAX]);
+
+    syscall_nr = ctx->uc_mcontext.gregs[REG_RAX] - 0xf000;
+    if (syscall_nr >= __wine_nb_syscalls)
+    {
+        ERR("Syscall %u is undefined.\n", syscall_nr);
+        return;
+    }
+
+    rsp = (void ***)&ctx->uc_mcontext.gregs[REG_RSP];
+    *rsp -= 1;
+
+#ifdef __APPLE__
+    thunk_ret_offset = 0xb;
+#else
+    thunk_ret_offset = 0xc;
+#endif
+
+    **rsp = (void *)(ctx->uc_mcontext.gregs[REG_RIP] + thunk_ret_offset);
+    ctx->uc_mcontext.gregs[REG_RIP] = (ULONG64)__wine_syscall_dispatcher;
+}
+#endif
 
 /***********************************************************************
  *           __wine_set_signal_handler   (NTDLL.@)
@@ -3266,6 +3306,53 @@ void signal_init_thread( TEB *teb )
 #endif
 }
 
+static void install_bpf(struct sigaction *sig_act)
+{
+#ifdef HAVE_SECCOMP
+    static struct sock_filter filter[] =
+    {
+       BPF_STMT(BPF_LD | BPF_W | BPF_ABS,
+                (offsetof(struct seccomp_data, nr))),
+       BPF_JUMP(BPF_JMP | BPF_JGE | BPF_K, 0xf000, 0, 1),
+       BPF_STMT(BPF_RET | BPF_K, SECCOMP_RET_TRAP),
+       BPF_STMT(BPF_RET | BPF_K, SECCOMP_RET_ALLOW),
+    };
+    struct sock_fprog prog;
+    int ret;
+
+    memset(&prog, 0, sizeof(prog));
+    prog.len = ARRAY_SIZE(filter);
+    prog.filter = filter;
+
+    if (!(ret = prctl(PR_GET_SECCOMP, 0, NULL, 0, 0)))
+    {
+        if (prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0))
+        {
+            perror("prctl(PR_SET_NO_NEW_PRIVS, ...)");
+            exit(1);
+        }
+
+        if (prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0))
+        {
+            perror("prctl(PR_SET_SECCOMP, ...)");
+            exit(1);
+        }
+    }
+    else
+    {
+        if (ret == 2)
+            TRACE("Seccomp filters already installed.\n");
+        else
+            ERR("Seccomp filters cannot be installed, ret %d, error %s.\n", ret, strerror(errno));
+    }
+
+    sig_act->sa_sigaction = sigsys_handler;
+    sigaction(SIGSYS, sig_act, NULL);
+#else
+    WARN("Built without seccomp.\n");
+#endif
+}
+
 /**********************************************************************
  *		signal_init_process
  */
@@ -3298,6 +3385,9 @@ void signal_init_process(void)
     sig_act.sa_sigaction = trap_handler;
     if (sigaction( SIGTRAP, &sig_act, NULL ) == -1) goto error;
 #endif
+
+    install_bpf(&sig_act);
+
     return;
 
  error:

include/config.h.in

@@ -500,6 +500,9 @@
 /* Define to 1 if you have the <linux/rtnetlink.h> header file. */
 #undef HAVE_LINUX_RTNETLINK_H
 
+/* Define to 1 if you have the <linux/seccomp.h> header file. */
+#undef HAVE_LINUX_SECCOMP_H
+
 /* Define to 1 if you have the <linux/serial.h> header file. */
 #undef HAVE_LINUX_SERIAL_H
 

tools/winebuild/spec32.c

@@ -531,7 +531,7 @@ static void output_syscall_thunks_x64( DLLSPEC *spec )
         output_cfi( ".cfi_startproc" );
         output( "\t.byte 0x4c,0x8b,0xd1\n" );                               /* mov r10, rcx */
         output( "\t.byte 0xb8\n" );                                         /* mov eax, SYSCALL */
-        output( "\t.long %d\n", i );
+        output( "\t.long %d\n", i + 0xf000 );
         output( "\t.byte 0xf6,0x04,0x25,0x08,0x03,0xfe,0x7f,0x01\n" );      /* test byte ptr [0x7ffe0308], 1 */
         output( "\t.byte 0x75,0x03\n" );                                    /* jne (over syscall) */
         output( "\t.byte 0x0f,0x05\n" );                                    /* syscall */
@@ -576,6 +576,9 @@ static void output_syscall_thunks_x64( DLLSPEC *spec )
         output( "\t.byte %d\n", max(get_args_size(odp), 32) - 32 );
     }
 
+    output( "%s\n", asm_globl("__wine_nb_syscalls") );
+    output( "\t.long %u\n", spec->nb_syscalls );
+
     output( "\n/* syscall dispatcher */\n\n" );
     output( "\t.text\n" );
     output( "\t.align %d\n", get_alignment(16) );
@@ -601,6 +604,8 @@ static void output_syscall_thunks_x64( DLLSPEC *spec )
     else
         output( "\tsubq $0xc,0x8(%%rbp)\n" );
 
+    output( "\tsub $0xf000,%%rax\n" );
+
     /* copy over any arguments on the stack */
     output( "\tleaq 0x38(%%rbp),%%rsi\n" );
     if (UsePIC)
@@ -1233,7 +1238,7 @@ static void create_stub_exports_text_x64( DLLSPEC *spec )
         align_output_rva( 16, 16 );
         put_label( odp->link_name );
         put_byte( 0x4c ); put_byte( 0x8b ); put_byte( 0xd1 );  /* mov r10, rcx */
-        put_byte( 0xb8 ); put_dword( i );                      /* mov eax, SYSCALL */
+        put_byte( 0xb8 ); put_dword( i + 0xf000 );             /* mov eax, SYSCALL */
         put_byte( 0xf6 ); put_byte( 0x04 ); put_byte( 0x25 );  /* test byte ptr [0x7ffe0308], 1 */
                 put_byte( 0x08 ); put_byte( 0x03 ); put_byte( 0xfe );
                 put_byte( 0x7f ); put_byte( 0x01 );