| #!/usr/bin/python |
| |
| # This tool is used to generate the assembler system call stubs, |
| # the header files listing all available system calls, and the |
| # makefiles used to build all the stubs. |
| |
| import commands |
| import filecmp |
| import glob |
| import os.path |
| import re |
| import shutil |
| import stat |
| import sys |
| |
| 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/" |
| |
| warning = "Generated by gensyscalls.py. Do not edit." |
| |
| DRY_RUN = False |
| |
| 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") |
| |
| |
| syscall_stub_header = "/* " + warning + " */\n" + \ |
| """ |
| #include <asm/unistd.h> |
| #include <linux/err.h> |
| #include <machine/asm.h> |
| |
| ENTRY(%(func)s) |
| """ |
| |
| |
| function_alias = """ |
| .globl _C_LABEL(%(alias)s) |
| .equ _C_LABEL(%(alias)s), _C_LABEL(%(func)s) |
| """ |
| |
| |
| # |
| # ARM assembler templates for each syscall stub |
| # |
| |
| arm_eabi_call_default = syscall_stub_header + """\ |
| mov ip, r7 |
| ldr r7, =%(__NR_name)s |
| swi #0 |
| mov r7, ip |
| cmn r0, #(MAX_ERRNO + 1) |
| bxls lr |
| neg r0, r0 |
| b __set_errno |
| END(%(func)s) |
| """ |
| |
| arm_eabi_call_long = syscall_stub_header + """\ |
| mov ip, sp |
| .save {r4, r5, r6, r7} |
| stmfd sp!, {r4, r5, r6, r7} |
| ldmfd ip, {r4, r5, r6} |
| ldr r7, =%(__NR_name)s |
| swi #0 |
| ldmfd sp!, {r4, r5, r6, r7} |
| cmn r0, #(MAX_ERRNO + 1) |
| bxls lr |
| neg r0, r0 |
| b __set_errno |
| END(%(func)s) |
| """ |
| |
| |
| # |
| # MIPS assembler templates for each syscall stub |
| # |
| |
| mips_call = "/* " + warning + " */\n" + \ |
| """ |
| #include <asm/unistd.h> |
| .text |
| .globl %(func)s |
| .align 4 |
| .ent %(func)s |
| |
| %(func)s: |
| .set noreorder |
| .cpload $t9 |
| li $v0, %(__NR_name)s |
| syscall |
| bnez $a3, 1f |
| move $a0, $v0 |
| j $ra |
| nop |
| 1: |
| la $t9,__set_errno |
| j $t9 |
| nop |
| .set reorder |
| .end %(func)s |
| """ |
| |
| |
| # |
| # x86 assembler templates for each syscall stub |
| # |
| |
| x86_registers = [ "%ebx", "%ecx", "%edx", "%esi", "%edi", "%ebp" ] |
| |
| x86_call = """\ |
| movl $%(__NR_name)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(%(func)s) |
| """ |
| |
| |
| # |
| # x86_64 assembler templates for each syscall stub |
| # |
| |
| x86_64_call = """\ |
| movl $%(__NR_name)s, %%eax |
| syscall |
| cmpq $-MAX_ERRNO, %%rax |
| jb 1f |
| negl %%eax |
| movl %%eax, %%edi |
| call __set_errno |
| orq $-1, %%rax |
| 1: |
| ret |
| END(%(func)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 |
| |
| |
| def count_generic_param_registers64(params): |
| count = 0 |
| for param in params: |
| 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) |
| |
| |
| def add_footer(pointer_length, stub, syscall): |
| # Add any aliases for this syscall. |
| aliases = syscall["aliases"] |
| for alias in aliases: |
| stub += function_alias % { "func" : syscall["func"], "alias" : alias } |
| |
| # Use hidden visibility for any functions beginning with underscores. |
| # TODO: clean up single-underscore names too. |
| if pointer_length == 64 and syscall["func"].startswith("__"): |
| stub += '.hidden _C_LABEL(' + syscall["func"] + ')\n' |
| |
| return stub |
| |
| |
| def arm_eabi_genstub(syscall): |
| num_regs = count_arm_param_registers(syscall["params"]) |
| if num_regs > 4: |
| return arm_eabi_call_long % syscall |
| return arm_eabi_call_default % syscall |
| |
| |
| def mips_genstub(syscall): |
| return mips_call % syscall |
| |
| |
| def x86_genstub(syscall): |
| result = syscall_stub_header % syscall |
| stack_bias = 4 |
| |
| numparams = count_generic_param_registers(syscall["params"]) |
| 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 % syscall |
| |
| for r in range(numparams): |
| result += " popl " + x86_registers[numparams-r-1] + "\n" |
| |
| result += x86_return % syscall |
| return result |
| |
| def x86_genstub_socketcall(syscall): |
| # %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()) |
| |
| result = syscall_stub_header % syscall |
| 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" % syscall["socketcall_id"] + "\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 % syscall |
| |
| # now restore the saved regs |
| result += " popl %ecx" + "\n" |
| result += " popl %ebx" + "\n" |
| |
| # epilog |
| result += x86_return % syscall |
| return result |
| |
| |
| def x86_64_genstub(syscall): |
| result = syscall_stub_header % syscall |
| num_regs = count_generic_param_registers64(syscall["params"]) |
| if (num_regs > 3): |
| # rcx is used as 4th argument. Kernel wants it at r10. |
| result += " movq %rcx, %r10\n" |
| |
| result += x86_64_call % syscall |
| return result |
| |
| |
| class State: |
| def __init__(self): |
| self.old_stubs = [] |
| self.new_stubs = [] |
| self.other_files = [] |
| self.syscalls = [] |
| |
| |
| def process_file(self, input): |
| parser = SysCallsTxtParser() |
| parser.parse_file(input) |
| self.syscalls = parser.syscalls |
| parser = None |
| |
| for syscall in self.syscalls: |
| syscall["__NR_name"] = make__NR_name(syscall["name"]) |
| |
| if syscall.has_key("arm"): |
| syscall["asm-arm"] = add_footer(32, arm_eabi_genstub(syscall), syscall) |
| |
| if syscall.has_key("x86"): |
| if syscall["socketcall_id"] >= 0: |
| syscall["asm-x86"] = add_footer(32, x86_genstub_socketcall(syscall), syscall) |
| else: |
| syscall["asm-x86"] = add_footer(32, x86_genstub(syscall), syscall) |
| elif syscall["socketcall_id"] >= 0: |
| E("socketcall_id for dispatch syscalls is only supported for x86 in '%s'" % t) |
| return |
| |
| if syscall.has_key("mips"): |
| syscall["asm-mips"] = add_footer(32, mips_genstub(syscall), syscall) |
| |
| if syscall.has_key("x86_64"): |
| syscall["asm-x86_64"] = add_footer(64, x86_64_genstub(syscall), syscall) |
| |
| |
| # 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("/* %s */\n" % warning) |
| 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("#elif defined(__x86_64__)\n") |
| self.scan_linux_unistd_h(glibc_fp, bionic_libc_root + "/kernel/arch-x86/asm/unistd_64.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) |
| |
| |
| # Write 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("# %s\n" % warning) |
| fp.write("syscall_src :=\n") |
| for syscall in sorted(self.syscalls, key=lambda syscall: syscall["func"]): |
| if syscall.has_key("asm-%s" % arch): |
| fp.write("syscall_src += arch-%s/syscalls/%s.S\n" % (arch, syscall["func"])) |
| fp.close() |
| self.other_files.append(path) |
| |
| |
| # Write each syscall stub. |
| def gen_syscall_stubs(self): |
| for syscall in self.syscalls: |
| for arch in all_arches: |
| if syscall.has_key("asm-%s" % arch): |
| filename = "arch-%s/syscalls/%s.S" % (arch, syscall["func"]) |
| D2(">>> generating " + filename) |
| fp = create_file(filename) |
| fp.write(syscall["asm-%s" % arch]) |
| fp.close() |
| self.new_stubs.append(filename) |
| |
| |
| def regenerate(self): |
| D("scanning for existing architecture-specific stub files...") |
| |
| bionic_libc_root_len = len(bionic_libc_root) |
| |
| for arch in all_arches: |
| 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_arches: |
| 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 not DRY_RUN: |
| 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() |
