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Merge "Refactor the syscall generation script."

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Elliott Hughes 2013-10-08 16:53:02 +00:00 committed by Gerrit Code Review
commit 5d06718cd3
1 changed files with 185 additions and 179 deletions
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364
libc/tools/gensyscalls.py
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@ -23,6 +23,7 @@ def make_dir(path):
make_dir(parent)
os.mkdir(path)
def create_file(relpath):
dir = os.path.dirname(bionic_temp + relpath)
make_dir(dir)
@ -34,21 +35,85 @@ syscall_stub_header = """/* autogenerated by gensyscalls.py */
#include <linux/err.h>
#include <machine/asm.h>
ENTRY(%(fname)s)
ENTRY(%(func)s)
"""
function_alias = """
.globl _C_LABEL(%(alias)s)
.equ _C_LABEL(%(alias)s), _C_LABEL(%(fname)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 = """/* autogenerated by gensyscalls.py */
#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 $%(idname)s, %%eax
x86_call = """\
movl $%(__NR_name)s, %%eax
int $0x80
cmpl $-MAX_ERRNO, %%eax
jb 1f
@ -60,15 +125,18 @@ x86_call = """ movl $%(idname)s, %%eax
1:
"""
x86_return = """ ret
END(%(fname)s)
x86_return = """\
ret
END(%(func)s)
"""
#
# x86_64 assembler templates for each syscall stub
#
x86_64_call = """ movl $%(idname)s, %%eax
x86_64_call = """\
movl $%(__NR_name)s, %%eax
syscall
cmpq $-MAX_ERRNO, %%rax
jb 1f
@ -78,67 +146,9 @@ x86_64_call = """ movl $%(idname)s, %%eax
orq $-1, %%rax
1:
ret
END(%(fname)s)
END(%(func)s)
"""
#
# ARM assembler templates for each syscall stub
#
arm_eabi_call_default = syscall_stub_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 = syscall_stub_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
@ -160,6 +170,7 @@ def param_uses_64bits(param):
# 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.
@ -184,6 +195,7 @@ def count_arm_param_registers(params):
count += 1
return count
def count_generic_param_registers(params):
count = 0
for param in params:
@ -193,12 +205,14 @@ def count_generic_param_registers(params):
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):
@ -207,6 +221,90 @@ def make__NR_name(name):
else:
return "__NR_%s" % (name)
def add_aliases(stub, syscall):
aliases = syscall["aliases"]
for alias in aliases:
stub += function_alias % { "func" : syscall["func"], "alias" : alias }
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 = []
@ -214,126 +312,34 @@ class State:
self.other_files = []
self.syscalls = []
def x86_64_genstub(self, fname, numparams, idname, aliases):
t = { "fname" : fname, "idname" : idname }
result = syscall_stub_header % t
# rcx is used as 4th argument. Kernel wants it at r10.
if (numparams > 3):
result += " movq %rcx, %r10\n"
result += x86_64_call % t
for alias in aliases:
t = { "fname" : fname, "alias" : alias }
result += function_alias % t
return result
def x86_genstub(self, fname, numparams, idname):
t = { "fname" : fname,
"idname" : idname }
result = syscall_stub_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_socketcall(self, fname, idname, socketcall_id):
# %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 = syscall_stub_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" % (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 % 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):
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_aliases = t["aliases"]
syscall_params = t["params"]
syscall_name = t["name"]
__NR_name = make__NR_name(t["name"])
for syscall in self.syscalls:
syscall["__NR_name"] = make__NR_name(syscall["name"])
if t.has_key("arm"):
num_regs = count_arm_param_registers(syscall_params)
t["asm-arm"] = self.arm_eabi_genstub(syscall_func, num_regs, __NR_name)
if syscall.has_key("arm"):
syscall["asm-arm"] = add_aliases(arm_eabi_genstub(syscall), syscall)
if t.has_key("x86"):
num_regs = count_generic_param_registers(syscall_params)
if t["socketcall_id"] >= 0:
t["asm-x86"] = self.x86_genstub_socketcall(syscall_func, __NR_name, t["socketcall_id"])
if syscall.has_key("x86"):
if syscall["socketcall_id"] >= 0:
syscall["asm-x86"] = add_aliases(x86_genstub_socketcall(syscall), syscall)
else:
t["asm-x86"] = self.x86_genstub(syscall_func, num_regs, __NR_name)
elif t["socketcall_id"] >= 0:
syscall["asm-x86"] = add_aliases(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 t.has_key("mips"):
t["asm-mips"] = self.mips_genstub(syscall_func, make__NR_name(syscall_name))
if syscall.has_key("mips"):
syscall["asm-mips"] = add_aliases(mips_genstub(syscall), syscall)
if syscall.has_key("x86_64"):
syscall["asm-x86_64"] = add_aliases(x86_64_genstub(syscall), syscall)
if t.has_key("x86_64"):
num_regs = count_generic_param_registers64(syscall_params)
t["asm-x86_64"] = self.x86_64_genstub(syscall_func, num_regs, __NR_name, syscall_aliases)
# Scan a Linux kernel asm/unistd.h file containing __NR_* constants
# and write out equivalent SYS_* constants for glibc source compatibility.
@ -379,22 +385,22 @@ class State:
fp = create_file(path)
fp.write("# Auto-generated by gensyscalls.py. Do not edit.\n")
fp.write("syscall_src :=\n")
for sc in self.syscalls:
if sc.has_key("asm-%s" % arch):
fp.write("syscall_src += arch-%s/syscalls/%s.S\n" % (arch, sc["func"]))
for syscall in self.syscalls:
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 sc in self.syscalls:
for syscall in self.syscalls:
for arch in all_arches:
if sc.has_key("asm-%s" % arch):
filename = "arch-%s/syscalls/%s.S" % (arch, sc["func"])
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(sc["asm-%s" % arch])
fp.write(syscall["asm-%s" % arch])
fp.close()
self.new_stubs.append(filename)