Implement minimalistic Linux environment and syscall table for x86_32

3 files changed, 60 insertions, 0 deletions

diff --git a/miasm/arch/x86/jit.py b/miasm/arch/x86/jit.py
index 3c0d1b33..0144c289 100644
--- a/miasm/arch/x86/jit.py
+++ b/miasm/arch/x86/jit.py
@@ -182,6 +182,17 @@ class jitter_x86_32(Jitter):
             return getattr(self.cpu, args_regs[index])
         return self.get_stack_arg(index - len(args_regs))
 
+    def syscall_args_systemv(self, n_args):
+        # Documentation: http://man7.org/linux/man-pages/man2/syscall.2.html
+        # args: 
+        #   i386          ebx   ecx   edx   esi   edi   ebp   -
+        args = [self.cpu.EBX, self.cpu.ECX, self.cpu.EDX, self.cpu.ESI,
+                self.cpu.EDI, self.cpu.EBP][:n_args]
+        return args
+
+    def syscall_ret_systemv(self, value):
+        # Documentation: http://man7.org/linux/man-pages/man2/syscall.2.html
+        self.cpu.EAX = value
 
 
 class jitter_x86_64(Jitter):
diff --git a/miasm/os_dep/linux/environment.py b/miasm/os_dep/linux/environment.py
index 07a7c9d4..53a97ce8 100644
--- a/miasm/os_dep/linux/environment.py
+++ b/miasm/os_dep/linux/environment.py
@@ -666,6 +666,19 @@ class LinuxEnvironment(object):
         return addr
 
 
+class LinuxEnvironment_x86_32(LinuxEnvironment):
+    platform_arch = b"x86_32"
+    sys_machine = b"x86_32"
+
+    # TODO FIXME
+    ## O_ACCMODE = 0x3
+    ## O_CLOEXEC = 0x80000
+    ## O_DIRECTORY = 0x10000
+    ## O_LARGEFILE = 0x8000
+    ## O_NONBLOCK = 0x800
+    ## O_RDONLY = 0
+
+
 class LinuxEnvironment_x86_64(LinuxEnvironment):
     platform_arch = b"x86_64"
     sys_machine = b"x86_64"
diff --git a/miasm/os_dep/linux/syscall.py b/miasm/os_dep/linux/syscall.py
index ca631fc8..fc6bbd8a 100644
--- a/miasm/os_dep/linux/syscall.py
+++ b/miasm/os_dep/linux/syscall.py
@@ -89,6 +89,37 @@ def sys_generic_brk(jitter, linux_env):
     jitter.syscall_ret_systemv(linux_env.brk(addr, jitter.vm))
 
 
+def sys_x86_32_newuname(jitter, linux_env):
+    # struct utsname {
+    #     char sysname[];    /* Operating system name (e.g., "Linux") */
+    #     char nodename[];   /* Name within "some implementation-defined
+    #                            network" */
+    #     char release[];    /* Operating system release (e.g., "2.6.28") */
+    #     char version[];    /* Operating system version */
+    #     char machine[];    /* Hardware identifier */
+    # }
+
+    # Parse arguments
+    nameptr, = jitter.syscall_args_systemv(1)
+    log.debug("sys_newuname(%x)", nameptr)
+
+    # Stub
+    info = [
+        linux_env.sys_sysname,
+        linux_env.sys_nodename,
+        linux_env.sys_release,
+        linux_env.sys_version,
+        linux_env.sys_machine
+    ]
+    # TODO: Elements start at 0x41 multiples on my tests...
+    output = b""
+    for elem in info:
+        output += elem
+        output += b"\x00" * (0x41 - len(elem))
+    jitter.vm.set_mem(nameptr, output)
+    jitter.syscall_ret_systemv(0)
+
+
 def sys_x86_64_newuname(jitter, linux_env):
     # struct utsname {
     #     char sysname[];    /* Operating system name (e.g., "Linux") */
@@ -867,6 +898,11 @@ def sys_arml_gettimeofday(jitter, linux_env):
     jitter.cpu.R0 = 0
 
 
+syscall_callbacks_x86_32 = {
+    0x7A: sys_x86_32_newuname,
+}
+
+
 syscall_callbacks_x86_64 = {
     0x0: sys_generic_read,
     0x1: sys_generic_write,