456 lines
		
	
	
		
			14 KiB
		
	
	
	
		
			Python
		
	
	
		
			Executable File
		
	
	
	
	
			
		
		
	
	
			456 lines
		
	
	
		
			14 KiB
		
	
	
	
		
			Python
		
	
	
		
			Executable File
		
	
	
	
	
#!/usr/bin/python
 | 
						|
#
 | 
						|
# this tool is used to generate the syscall assembler templates
 | 
						|
# to be placed into arch-{arm,x86,mips}/syscalls, as well as the content
 | 
						|
# of arch-{arm,x86,mips}/linux/_syscalls.h
 | 
						|
#
 | 
						|
 | 
						|
import sys, os.path, glob, re, commands, filecmp, shutil
 | 
						|
import getpass
 | 
						|
 | 
						|
from bionic_utils import *
 | 
						|
 | 
						|
bionic_libc_root = os.environ["ANDROID_BUILD_TOP"] + "/bionic/libc/"
 | 
						|
 | 
						|
# temp directory where we store all intermediate files
 | 
						|
bionic_temp = "/tmp/bionic_gensyscalls/"
 | 
						|
 | 
						|
# all architectures, update as you see fit
 | 
						|
all_archs = [ "arm", "mips", "x86" ]
 | 
						|
 | 
						|
def make_dir( path ):
 | 
						|
    path = os.path.abspath(path)
 | 
						|
    if not os.path.exists(path):
 | 
						|
        parent = os.path.dirname(path)
 | 
						|
        if parent:
 | 
						|
            make_dir(parent)
 | 
						|
        os.mkdir(path)
 | 
						|
 | 
						|
def create_file( relpath ):
 | 
						|
    dir = os.path.dirname( bionic_temp + relpath )
 | 
						|
    make_dir(dir)
 | 
						|
    return open( bionic_temp + relpath, "w" )
 | 
						|
 | 
						|
#
 | 
						|
# x86 assembler templates for each syscall stub
 | 
						|
#
 | 
						|
 | 
						|
x86_header = """/* autogenerated by gensyscalls.py */
 | 
						|
#include <linux/err.h>
 | 
						|
#include <machine/asm.h>
 | 
						|
#include <asm/unistd.h>
 | 
						|
 | 
						|
ENTRY(%(fname)s)
 | 
						|
"""
 | 
						|
 | 
						|
x86_registers = [ "%ebx", "%ecx", "%edx", "%esi", "%edi", "%ebp" ]
 | 
						|
 | 
						|
x86_call = """    movl    $%(idname)s, %%eax
 | 
						|
    int     $0x80
 | 
						|
    cmpl    $-MAX_ERRNO, %%eax
 | 
						|
    jb      1f
 | 
						|
    negl    %%eax
 | 
						|
    pushl   %%eax
 | 
						|
    call    __set_errno
 | 
						|
    addl    $4, %%esp
 | 
						|
    orl     $-1, %%eax
 | 
						|
1:
 | 
						|
"""
 | 
						|
 | 
						|
x86_return = """    ret
 | 
						|
END(%(fname)s)
 | 
						|
"""
 | 
						|
 | 
						|
#
 | 
						|
# ARM assembler templates for each syscall stub
 | 
						|
#
 | 
						|
 | 
						|
arm_header = """/* autogenerated by gensyscalls.py */
 | 
						|
#include <asm/unistd.h>
 | 
						|
#include <linux/err.h>
 | 
						|
#include <machine/asm.h>
 | 
						|
 | 
						|
ENTRY(%(fname)s)
 | 
						|
"""
 | 
						|
 | 
						|
arm_eabi_call_default = arm_header + """\
 | 
						|
    mov     ip, r7
 | 
						|
    ldr     r7, =%(idname)s
 | 
						|
    swi     #0
 | 
						|
    mov     r7, ip
 | 
						|
    cmn     r0, #(MAX_ERRNO + 1)
 | 
						|
    bxls    lr
 | 
						|
    neg     r0, r0
 | 
						|
    b       __set_errno
 | 
						|
END(%(fname)s)
 | 
						|
"""
 | 
						|
 | 
						|
arm_eabi_call_long = arm_header + """\
 | 
						|
    mov     ip, sp
 | 
						|
    .save   {r4, r5, r6, r7}
 | 
						|
    stmfd   sp!, {r4, r5, r6, r7}
 | 
						|
    ldmfd   ip, {r4, r5, r6}
 | 
						|
    ldr     r7, =%(idname)s
 | 
						|
    swi     #0
 | 
						|
    ldmfd   sp!, {r4, r5, r6, r7}
 | 
						|
    cmn     r0, #(MAX_ERRNO + 1)
 | 
						|
    bxls    lr
 | 
						|
    neg     r0, r0
 | 
						|
    b       __set_errno
 | 
						|
END(%(fname)s)
 | 
						|
"""
 | 
						|
 | 
						|
#
 | 
						|
# mips assembler templates for each syscall stub
 | 
						|
#
 | 
						|
 | 
						|
mips_call = """/* autogenerated by gensyscalls.py */
 | 
						|
#include <asm/unistd.h>
 | 
						|
    .text
 | 
						|
    .globl %(fname)s
 | 
						|
    .align 4
 | 
						|
    .ent %(fname)s
 | 
						|
 | 
						|
%(fname)s:
 | 
						|
    .set noreorder
 | 
						|
    .cpload $t9
 | 
						|
    li $v0, %(idname)s
 | 
						|
    syscall
 | 
						|
    bnez $a3, 1f
 | 
						|
    move $a0, $v0
 | 
						|
    j $ra
 | 
						|
    nop
 | 
						|
1:
 | 
						|
    la $t9,__set_errno
 | 
						|
    j $t9
 | 
						|
    nop
 | 
						|
    .set reorder
 | 
						|
    .end %(fname)s
 | 
						|
"""
 | 
						|
 | 
						|
def param_uses_64bits(param):
 | 
						|
    """Returns True iff a syscall parameter description corresponds
 | 
						|
       to a 64-bit type."""
 | 
						|
    param = param.strip()
 | 
						|
    # First, check that the param type begins with one of the known
 | 
						|
    # 64-bit types.
 | 
						|
    if not ( \
 | 
						|
       param.startswith("int64_t") or param.startswith("uint64_t") or \
 | 
						|
       param.startswith("loff_t") or param.startswith("off64_t") or \
 | 
						|
       param.startswith("long long") or param.startswith("unsigned long long") or
 | 
						|
       param.startswith("signed long long") ):
 | 
						|
           return False
 | 
						|
 | 
						|
    # Second, check that there is no pointer type here
 | 
						|
    if param.find("*") >= 0:
 | 
						|
            return False
 | 
						|
 | 
						|
    # Ok
 | 
						|
    return True
 | 
						|
 | 
						|
def count_arm_param_registers(params):
 | 
						|
    """This function is used to count the number of register used
 | 
						|
       to pass parameters when invoking an ARM system call.
 | 
						|
       This is because the ARM EABI mandates that 64-bit quantities
 | 
						|
       must be passed in an even+odd register pair. So, for example,
 | 
						|
       something like:
 | 
						|
 | 
						|
             foo(int fd, off64_t pos)
 | 
						|
 | 
						|
       would actually need 4 registers:
 | 
						|
             r0 -> int
 | 
						|
             r1 -> unused
 | 
						|
             r2-r3 -> pos
 | 
						|
   """
 | 
						|
    count = 0
 | 
						|
    for param in params:
 | 
						|
        if param_uses_64bits(param):
 | 
						|
            if (count & 1) != 0:
 | 
						|
                count += 1
 | 
						|
            count += 2
 | 
						|
        else:
 | 
						|
            count += 1
 | 
						|
    return count
 | 
						|
 | 
						|
def count_generic_param_registers(params):
 | 
						|
    count = 0
 | 
						|
    for param in params:
 | 
						|
        if param_uses_64bits(param):
 | 
						|
            count += 2
 | 
						|
        else:
 | 
						|
            count += 1
 | 
						|
    return count
 | 
						|
 | 
						|
# This lets us support regular system calls like __NR_write and also weird
 | 
						|
# ones like __ARM_NR_cacheflush, where the NR doesn't come at the start.
 | 
						|
def make__NR_name(name):
 | 
						|
    if name.startswith("__"):
 | 
						|
        return name
 | 
						|
    else:
 | 
						|
        return "__NR_%s" % (name)
 | 
						|
 | 
						|
class State:
 | 
						|
    def __init__(self):
 | 
						|
        self.old_stubs = []
 | 
						|
        self.new_stubs = []
 | 
						|
        self.other_files = []
 | 
						|
        self.syscalls = []
 | 
						|
 | 
						|
    def x86_genstub(self, fname, numparams, idname):
 | 
						|
        t = { "fname"  : fname,
 | 
						|
              "idname" : idname }
 | 
						|
 | 
						|
        result     = x86_header % t
 | 
						|
        stack_bias = 4
 | 
						|
        for r in range(numparams):
 | 
						|
            result     += "    pushl   " + x86_registers[r] + "\n"
 | 
						|
            stack_bias += 4
 | 
						|
 | 
						|
        for r in range(numparams):
 | 
						|
            result += "    mov     %d(%%esp), %s" % (stack_bias+r*4, x86_registers[r]) + "\n"
 | 
						|
 | 
						|
        result += x86_call % t
 | 
						|
 | 
						|
        for r in range(numparams):
 | 
						|
            result += "    popl    " + x86_registers[numparams-r-1] + "\n"
 | 
						|
 | 
						|
        result += x86_return % t
 | 
						|
        return result
 | 
						|
 | 
						|
    def x86_genstub_cid(self, fname, numparams, idname, cid):
 | 
						|
        # We'll ignore numparams here because in reality, if there is a
 | 
						|
        # dispatch call (like a socketcall syscall) there are actually
 | 
						|
        # only 2 arguments to the syscall and 2 regs we have to save:
 | 
						|
        #   %ebx <--- Argument 1 - The call id of the needed vectored
 | 
						|
        #                          syscall (socket, bind, recv, etc)
 | 
						|
        #   %ecx <--- Argument 2 - Pointer to the rest of the arguments
 | 
						|
        #                          from the original function called (socket())
 | 
						|
        t = { "fname"  : fname,
 | 
						|
              "idname" : idname }
 | 
						|
 | 
						|
        result = x86_header % t
 | 
						|
        stack_bias = 4
 | 
						|
 | 
						|
        # save the regs we need
 | 
						|
        result += "    pushl   %ebx" + "\n"
 | 
						|
        stack_bias += 4
 | 
						|
        result += "    pushl   %ecx" + "\n"
 | 
						|
        stack_bias += 4
 | 
						|
 | 
						|
        # set the call id (%ebx)
 | 
						|
        result += "    mov     $%d, %%ebx" % (cid) + "\n"
 | 
						|
 | 
						|
        # set the pointer to the rest of the args into %ecx
 | 
						|
        result += "    mov     %esp, %ecx" + "\n"
 | 
						|
        result += "    addl    $%d, %%ecx" % (stack_bias) + "\n"
 | 
						|
 | 
						|
        # now do the syscall code itself
 | 
						|
        result += x86_call % t
 | 
						|
 | 
						|
        # now restore the saved regs
 | 
						|
        result += "    popl    %ecx" + "\n"
 | 
						|
        result += "    popl    %ebx" + "\n"
 | 
						|
 | 
						|
        # epilog
 | 
						|
        result += x86_return % t
 | 
						|
        return result
 | 
						|
 | 
						|
 | 
						|
    def arm_eabi_genstub(self,fname, flags, idname):
 | 
						|
        t = { "fname"  : fname,
 | 
						|
              "idname" : idname }
 | 
						|
        if flags:
 | 
						|
            numargs = int(flags)
 | 
						|
            if numargs > 4:
 | 
						|
                return arm_eabi_call_long % t
 | 
						|
        return arm_eabi_call_default % t
 | 
						|
 | 
						|
 | 
						|
    def mips_genstub(self,fname, idname):
 | 
						|
        t = { "fname"  : fname,
 | 
						|
              "idname" : idname }
 | 
						|
        return mips_call % t
 | 
						|
 | 
						|
    def process_file(self,input):
 | 
						|
        parser = SysCallsTxtParser()
 | 
						|
        parser.parse_file(input)
 | 
						|
        self.syscalls = parser.syscalls
 | 
						|
        parser = None
 | 
						|
 | 
						|
        for t in self.syscalls:
 | 
						|
            syscall_func   = t["func"]
 | 
						|
            syscall_params = t["params"]
 | 
						|
            syscall_name   = t["name"]
 | 
						|
 | 
						|
            if t["common"] >= 0 or t["armid"] >= 0:
 | 
						|
                num_regs = count_arm_param_registers(syscall_params)
 | 
						|
                t["asm-arm"] = self.arm_eabi_genstub(syscall_func, num_regs, make__NR_name(syscall_name))
 | 
						|
 | 
						|
            if t["common"] >= 0 or t["x86id"] >= 0:
 | 
						|
                num_regs = count_generic_param_registers(syscall_params)
 | 
						|
                if t["cid"] >= 0:
 | 
						|
                    t["asm-x86"] = self.x86_genstub_cid(syscall_func, num_regs, make__NR_name(syscall_name), t["cid"])
 | 
						|
                else:
 | 
						|
                    t["asm-x86"] = self.x86_genstub(syscall_func, num_regs, make__NR_name(syscall_name))
 | 
						|
            elif t["cid"] >= 0:
 | 
						|
                E("cid for dispatch syscalls is only supported for x86 in "
 | 
						|
                  "'%s'" % syscall_name)
 | 
						|
                return
 | 
						|
 | 
						|
            if t["common"] >= 0 or t["mipsid"] >= 0:
 | 
						|
                t["asm-mips"] = self.mips_genstub(syscall_func, make__NR_name(syscall_name))
 | 
						|
 | 
						|
 | 
						|
    # Scan a Linux kernel asm/unistd.h file containing __NR_* constants
 | 
						|
    # and write out equivalent SYS_* constants for glibc source compatibility.
 | 
						|
    def scan_linux_unistd_h(self, fp, path):
 | 
						|
        pattern = re.compile(r'^#define __NR_([a-z]\S+) .*')
 | 
						|
        syscalls = set() # MIPS defines everything three times; work around that.
 | 
						|
        for line in open(path):
 | 
						|
            m = re.search(pattern, line)
 | 
						|
            if m:
 | 
						|
                syscalls.add(m.group(1))
 | 
						|
        for syscall in sorted(syscalls):
 | 
						|
            fp.write("#define SYS_%s %s\n" % (syscall, make__NR_name(syscall)))
 | 
						|
 | 
						|
 | 
						|
    def gen_glibc_syscalls_h(self):
 | 
						|
        # TODO: generate a separate file for each architecture, like glibc's bits/syscall.h.
 | 
						|
        glibc_syscalls_h_path = "include/sys/glibc-syscalls.h"
 | 
						|
        D("generating " + glibc_syscalls_h_path)
 | 
						|
        glibc_fp = create_file(glibc_syscalls_h_path)
 | 
						|
        glibc_fp.write("/* Auto-generated by gensyscalls.py; do not edit. */\n")
 | 
						|
        glibc_fp.write("#ifndef _BIONIC_GLIBC_SYSCALLS_H_\n")
 | 
						|
        glibc_fp.write("#define _BIONIC_GLIBC_SYSCALLS_H_\n")
 | 
						|
 | 
						|
        glibc_fp.write("#if defined(__arm__)\n")
 | 
						|
        self.scan_linux_unistd_h(glibc_fp, bionic_libc_root + "/kernel/arch-arm/asm/unistd.h")
 | 
						|
        glibc_fp.write("#elif defined(__mips__)\n")
 | 
						|
        self.scan_linux_unistd_h(glibc_fp, bionic_libc_root + "/kernel/arch-mips/asm/unistd.h")
 | 
						|
        glibc_fp.write("#elif defined(__i386__)\n")
 | 
						|
        self.scan_linux_unistd_h(glibc_fp, bionic_libc_root + "/kernel/arch-x86/asm/unistd_32.h")
 | 
						|
        glibc_fp.write("#endif\n")
 | 
						|
 | 
						|
        glibc_fp.write("#endif /* _BIONIC_GLIBC_SYSCALLS_H_ */\n")
 | 
						|
        glibc_fp.close()
 | 
						|
        self.other_files.append(glibc_syscalls_h_path)
 | 
						|
 | 
						|
 | 
						|
    # now dump the contents of syscalls.mk
 | 
						|
    def gen_arch_syscalls_mk(self, arch):
 | 
						|
        path = "arch-%s/syscalls.mk" % arch
 | 
						|
        D( "generating "+path )
 | 
						|
        fp = create_file( path )
 | 
						|
        fp.write( "# auto-generated by gensyscalls.py, do not touch\n" )
 | 
						|
        fp.write( "syscall_src := \n" )
 | 
						|
        arch_test = {
 | 
						|
            "arm": lambda x: x.has_key("asm-arm"),
 | 
						|
            "x86": lambda x: x.has_key("asm-x86"),
 | 
						|
            "mips": lambda x: x.has_key("asm-mips")
 | 
						|
        }
 | 
						|
 | 
						|
        for sc in self.syscalls:
 | 
						|
            if arch_test[arch](sc):
 | 
						|
                fp.write("syscall_src += arch-%s/syscalls/%s.S\n" %
 | 
						|
                         (arch, sc["func"]))
 | 
						|
        fp.close()
 | 
						|
        self.other_files.append( path )
 | 
						|
 | 
						|
 | 
						|
    # now generate each syscall stub
 | 
						|
    def gen_syscall_stubs(self):
 | 
						|
        for sc in self.syscalls:
 | 
						|
            if sc.has_key("asm-arm") and 'arm' in all_archs:
 | 
						|
                fname = "arch-arm/syscalls/%s.S" % sc["func"]
 | 
						|
                D2( ">>> generating "+fname )
 | 
						|
                fp = create_file( fname )
 | 
						|
                fp.write(sc["asm-arm"])
 | 
						|
                fp.close()
 | 
						|
                self.new_stubs.append( fname )
 | 
						|
 | 
						|
            if sc.has_key("asm-x86") and 'x86' in all_archs:
 | 
						|
                fname = "arch-x86/syscalls/%s.S" % sc["func"]
 | 
						|
                D2( ">>> generating "+fname )
 | 
						|
                fp = create_file( fname )
 | 
						|
                fp.write(sc["asm-x86"])
 | 
						|
                fp.close()
 | 
						|
                self.new_stubs.append( fname )
 | 
						|
 | 
						|
            if sc.has_key("asm-mips") and 'mips' in all_archs:
 | 
						|
                fname = "arch-mips/syscalls/%s.S" % sc["func"]
 | 
						|
                D2( ">>> generating "+fname )
 | 
						|
                fp = create_file( fname )
 | 
						|
                fp.write(sc["asm-mips"])
 | 
						|
                fp.close()
 | 
						|
                self.new_stubs.append( fname )
 | 
						|
 | 
						|
    def  regenerate(self):
 | 
						|
        D( "scanning for existing architecture-specific stub files" )
 | 
						|
 | 
						|
        bionic_libc_root_len = len(bionic_libc_root)
 | 
						|
 | 
						|
        for arch in all_archs:
 | 
						|
            arch_path = bionic_libc_root + "arch-" + arch
 | 
						|
            D( "scanning " + arch_path )
 | 
						|
            files = glob.glob( arch_path + "/syscalls/*.S" )
 | 
						|
            for f in files:
 | 
						|
                self.old_stubs.append( f[bionic_libc_root_len:] )
 | 
						|
 | 
						|
        D( "found %d stub files" % len(self.old_stubs) )
 | 
						|
 | 
						|
        if not os.path.exists( bionic_temp ):
 | 
						|
            D( "creating %s" % bionic_temp )
 | 
						|
            make_dir( bionic_temp )
 | 
						|
 | 
						|
        D( "re-generating stubs and support files" )
 | 
						|
 | 
						|
        self.gen_glibc_syscalls_h()
 | 
						|
        for arch in all_archs:
 | 
						|
            self.gen_arch_syscalls_mk(arch)
 | 
						|
        self.gen_syscall_stubs()
 | 
						|
 | 
						|
        D( "comparing files" )
 | 
						|
        adds    = []
 | 
						|
        edits   = []
 | 
						|
 | 
						|
        for stub in self.new_stubs + self.other_files:
 | 
						|
            if not os.path.exists( bionic_libc_root + stub ):
 | 
						|
                # new file, git add it
 | 
						|
                D( "new file:     " + stub)
 | 
						|
                adds.append( bionic_libc_root + stub )
 | 
						|
                shutil.copyfile( bionic_temp + stub, bionic_libc_root + stub )
 | 
						|
 | 
						|
            elif not filecmp.cmp( bionic_temp + stub, bionic_libc_root + stub ):
 | 
						|
                D( "changed file: " + stub)
 | 
						|
                edits.append( stub )
 | 
						|
 | 
						|
        deletes = []
 | 
						|
        for stub in self.old_stubs:
 | 
						|
            if not stub in self.new_stubs:
 | 
						|
                D( "deleted file: " + stub)
 | 
						|
                deletes.append( bionic_libc_root + stub )
 | 
						|
 | 
						|
 | 
						|
        if adds:
 | 
						|
            commands.getoutput("git add " + " ".join(adds))
 | 
						|
        if deletes:
 | 
						|
            commands.getoutput("git rm " + " ".join(deletes))
 | 
						|
        if edits:
 | 
						|
            for file in edits:
 | 
						|
                shutil.copyfile( bionic_temp + file, bionic_libc_root + file )
 | 
						|
            commands.getoutput("git add " +
 | 
						|
                               " ".join((bionic_libc_root + file) for file in edits))
 | 
						|
 | 
						|
        commands.getoutput("git add %s%s" % (bionic_libc_root,"SYSCALLS.TXT"))
 | 
						|
 | 
						|
        if (not adds) and (not deletes) and (not edits):
 | 
						|
            D("no changes detected!")
 | 
						|
        else:
 | 
						|
            D("ready to go!!")
 | 
						|
 | 
						|
D_setlevel(1)
 | 
						|
 | 
						|
state = State()
 | 
						|
state.process_file(bionic_libc_root+"SYSCALLS.TXT")
 | 
						|
state.regenerate()
 |