aboutsummaryrefslogtreecommitdiff
path: root/sysdeps/unix/make-syscalls.sh
blob: 0ec8b28fd21f8ac6c4e3bde45e5127a2735ec613 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
#! /bin/sh

# Usage: make-syscalls.sh ../sysdeps/unix/common
# Expects $sysdirs in environment.

##############################################################################

# Syscall Signature Key Letters for BP Thunks:
#
# a: unchecked address (e.g., 1st arg to mmap)
# b: non-NULL buffer (e.g., 2nd arg to read; return value from mmap)
# B: optionally-NULL buffer (e.g., 4th arg to getsockopt)
# f: buffer of 2 ints (e.g., 4th arg to socketpair)
# F: 3rd arg to fcntl
# i: scalar (any signedness & size: int, long, long long, enum, whatever)
# I: 3rd arg to ioctl
# n: scalar buffer length (e.g., 3rd arg to read)
# N: pointer to value/return scalar buffer length (e.g., 6th arg to recvfrom)
# p: non-NULL pointer to typed object (e.g., any non-void* arg)
# P: optionally-NULL pointer to typed object (e.g., 2nd argument to gettimeofday)
# s: non-NULL string (e.g., 1st arg to open)
# S: optionally-NULL string (e.g., 1st arg to acct)
# v: vararg scalar (e.g., optional 3rd arg to open)
# V: byte-per-page vector (3rd arg to mincore)
# W: wait status, optionally-NULL pointer to int (e.g., 2nd arg of wait4)

ptr='[abBfFINpPsSWV]'	# all pointer keyletters
int='[inv]'		# all scalar keyletters
typ='[ifnNpP]'		# typed-arg keyletters: we capture type for use in thunk

##############################################################################

thisdir=$1; shift

echo ''
echo \#### DIRECTORY = $thisdir
# Check each sysdep dir with higher priority than this one,
# and remove from $calls all the functions found in other dirs.
# Punt when we reach the directory defining these syscalls.
sysdirs=`for dir in $sysdirs; do
	 test $dir = $thisdir && break; echo $dir; done`
echo \#### SYSDIRS = $sysdirs

# Get the list of system calls for this directory.
calls=`sed 's/#.*$//
/^[ 	]*$/d' $thisdir/syscalls.list`

calls=`echo "$calls" |
while read file caller rest; do
  # Remove each syscall that is implemented by a file in $dir.
  # If a syscall specified a "caller", then only compile that syscall
  # if the caller function is also implemented in this directory.
  srcfile=-;
  for dir in $sysdirs; do
     { test -f $dir/$file.c && srcfile=$dir/$file.c; } ||
     { test -f $dir/$file.S && srcfile=$dir/$file.S; } ||
     { test -f $dir/$file.s && srcfile=$dir/$file.s; } ||
     { test x$caller != x- &&
	{ { test -f $dir/$caller.c && srcfile=$dir/$caller.c; } ||
	  { test -f $dir/$caller.S && srcfile=$dir/$caller.S; } ||
	  { test -f $dir/$caller.s && srcfile=$dir/$caller.s; }; }; } && break;
  done;
  echo $file $srcfile $caller $rest;
done`

# Any calls left?
test -n "$calls" || exit 0

# Emit rules to compile the syscalls remaining in $calls.
echo "$calls" |
while read file srcfile caller syscall args strong weak; do

  case x"$syscall" in
  x-) callnum=_ ;;
  *)
  # Figure out if $syscall is defined with a number in syscall.h.
  callnum=-
  eval `{ echo "#include <sysdep.h>";
	echo "callnum=SYS_ify ($syscall)"; } |
	  $asm_CPP -D__OPTIMIZE__ - |
	  sed -n -e "/^callnum=.*$syscall/d" \
		 -e "/^\(callnum=\)[ 	]*\(.*\)/s//\1'\2'/p"`
  ;;
  esac

  cancellable=
  noerrno=
  case $args in
  C*) cancellable=-cancel; args=`echo $args | sed 's/C:\?//'`;;
  E*) noerrno=_NOERRNO; args=`echo $args | sed 's/E:\?//'`;;
  V*) noerrno=_ERRVAL; args=`echo $args | sed 's/V:\?//'`;;
  esac

  # Derive the number of arguments from the argument signature
  case $args in
  [0-9]) nargs=$args;;
  ?:) nargs=0;;
  ?:?) nargs=1;;
  ?:??) nargs=2;;
  ?:???) nargs=3;;
  ?:????) nargs=4;;
  ?:?????) nargs=5;;
  ?:??????) nargs=6;;
  ?:???????) nargs=7;;
  ?:????????) nargs=8;;
  ?:?????????) nargs=9;;
  esac

  # Make sure only the first syscall rule is used, if multiple dirs
  # define the same syscall.
  echo ''
  echo "#### CALL=$file NUMBER=$callnum ARGS=$args SOURCE=$srcfile"

 case x$srcfile"$callnum" in
 x--)
  # Undefined callnum for an extra syscall.
  if [ x$caller != x- ]; then
    if [ x$noerrno != x ]; then
      echo >&2 "$0: no number for $fileno, no-error syscall ($strong $weak)"
      exit 2
    fi
    echo "unix-stub-syscalls += $strong $weak"
  fi
  ;;
 x*-) ;; ### Do nothing for undefined callnum
 x-*)
  echo "ifeq (,\$(filter $file,\$(unix-syscalls)))"

  case $weak in
  *@*)
    # The versioned symbols are only in the shared library.
    echo "ifneq (,\$(filter .os,\$(object-suffixes)))"
    ;;
  esac
  # Accumulate the list of syscall files for this directory.
  echo "unix-syscalls += $file"
  test x$caller = x- || echo "unix-extra-syscalls += $file"

  # Emit a compilation rule for this syscall.
  case $weak in
  *@*)
    # The versioned symbols are only in the shared library.
    echo "\
shared-only-routines += $file
\$(objpfx)${file}.os: \\"
    ;;
  *)
    echo "\
\$(foreach o,\$(object-suffixes),\$(objpfx)$file\$o) \
\$(foreach o,\$(object-suffixes),\$(objpfx)ptw-$file\$o) \
\$(objpfx)rtld-$file.os: \\"
    ;;
  esac

  echo "		\$(common-objpfx)s-proto$cancellable.d"
  case x"$callnum" in
  x_)
  echo "\
	(echo '/* Dummy module requested by syscalls.list */'; \\"
  ;;
  x*)
  echo "\
	\$(make-target-directory)
	(echo '#include <sysdep$cancellable.h>'; \\
	 echo 'PSEUDO$noerrno ($strong, $syscall, $nargs)'; \\
	 echo '	ret$noerrno'; \\
	 echo 'PSEUDO_END$noerrno($strong)'; \\
	 echo 'libc_hidden_def ($strong)'; \\"
  ;;
  esac

  # Append any weak aliases or versions defined for this syscall function.

  # A shortcoming in the current gas is that it will only allow one
  # version-alias per symbol.  So we create new strong aliases as needed.
  vcount=""

  for name in $weak; do
    case $name in
      *@@*)
	base=`echo $name | sed 's/@@.*//'`
	ver=`echo $name | sed 's/.*@@//'`
	if test -z "$vcount" ; then
	  source=$strong
	  vcount=1
	else
	  source="${strong}_${vcount}"
	  vcount=`expr $vcount + 1`
	  echo "	 echo 'strong_alias ($strong, $source)'; \\"
	fi
	echo "	 echo 'default_symbol_version($source, $base, $ver)'; \\"
	;;
      *@*)
	base=`echo $name | sed 's/@.*//'`
	ver=`echo $name | sed 's/.*@//'`
	if test -z "$vcount" ; then
	  source=$strong
	  vcount=1
	else
	  source="${strong}_${vcount}"
	  vcount=`expr $vcount + 1`
	  echo "	 echo 'strong_alias ($strong, $source)'; \\"
	fi
	echo "	 echo 'symbol_version($source, $base, $ver)'; \\"
	;;
      !*)
	name=`echo $name | sed 's/.//'`
	echo "	 echo 'strong_alias ($strong, $name)'; \\"
	echo "	 echo 'libc_hidden_def ($name)'; \\"
	;;
      *)
	echo "	 echo 'weak_alias ($strong, $name)'; \\"
	echo "	 echo 'libc_hidden_weak ($name)'; \\"
	;;
    esac
  done

  # And finally, pipe this all into the compiler.
  echo '	) | $(compile-syscall)'

  case $weak in
  *@*)
    # The versioned symbols are only in the shared library.
    echo endif
    ;;
  esac

  echo endif
 ;;
 esac

  case x"$callnum",$srcfile,$args in
  x[_-],-,* | x*,*.[sS],*V*) ;;
  x*,-,*$ptr* | x*,*.[sS],*$ptr*)

    nv_weak=`for name in $weak; do
		case $name in
		*@*) ;;
		*) echo $name;;
	        esac; done`

    # choose the name with the fewest leading underscores, preferably none
    set `echo $strong $nv_weak |tr '@ \t' ' \n\n' |sort -r`
    callname=$1

    # convert signature string to individual numbered arg names
    # e.g., i:ipbN -> i0 i1 p2 b3 N4
    set `echo $args |
	sed -e 's/^\(.\):\(.*\)/\2 <\10>/' \
	    -e 's/^\([^ ]\)\(.*\)/\2 <\11>/' \
	    -e 's/^\([^ ]\)\(.*\)/\2 <\12>/' \
	    -e 's/^\([^ ]\)\(.*\)/\2 <\13>/' \
	    -e 's/^\([^ ]\)\(.*\)/\2 <\14>/' \
	    -e 's/^\([^ ]\)\(.*\)/\2 <\15>/' \
	    -e 's/^\([^ ]\)\(.*\)/\2 <\16>/' \
	    -e 's/^\([^ ]\)\(.*\)/\2 <\17>/' \
	    -e 's/^\([^ ]\)\(.*\)/\2 <\18>/' \
	    -e 's/^\([^ ]\)\(.*\)/\2 <\19>/'`
    rtn=$1; shift
    args=$*
    arglist=`echo $* |sed 's/ /, /g'`

    # The best way to understand what's going on here is to examine
    # the output in BUILDDIR/sysd-syscalls.

    # generate makefile envelope & rule head
    echo "ifeq (,\$(filter $file,\$(bp-thunks)))"
    echo "bp-thunks += $file"
    echo "\$(objpfx)\$(bppfx)$file.ob: \$(common-objpfx)s-proto-bp.d"

    # generate macro head
    echo "	(echo '#define $callname(`echo $arglist | \
	    sed -e 's/[<>]//g'`) `echo $rtn | \
	    sed -e 's/<\('$typ'0\)>/\1v;/g' \
		-e 's/<\(b0\)>/x0; extern char \1v;/g'` \\'; \\"

    # generate extern decls of dummy variables for each arg
    echo "	 echo '`echo $args | \
	    sed -e 's/<\('$typ'[1-9]\)>/extern \1, \1v;/g' \
		-e 's/<\([abBFIsSV][1-9]\)>/extern char \1v;/g' \
		-e 's/<\([Wv][1-9]\)>/extern int \1v;/g'` \\'; \\"

    # generate bounded-pointer thunk declarator
    echo "	 echo '`echo $rtn | \
	    sed -e 's/<\('$ptr'0\)>/__typeof (\1v) *__bounded/g' \
		-e 's/<\('$int'0\)>/__typeof (\1v)/g'` BP_SYM ($strong) (`echo $arglist | \
	    sed -e 's/<\('$ptr'[1-9]\)>/__typeof (\1v) *__bounded \1a/g' \
		-e 's/<\('$int'[1-9]\)>/__typeof (\1v) \1a/g'`) { \\'; \\"

    # generate extern primitive syscall declaration
    echo "	 echo '  extern `echo $rtn | \
	    sed -e 's/<\('$ptr'0\)>/__typeof (\1v) *__unbounded/g' \
		-e 's/<\('$int'0\)>/__typeof (\1v)/g'` ($callname) (`echo $arglist | \
	    sed -e 's/<\('$ptr'[1-9]\)>/__typeof (\1v) *__unbounded/g' \
		-e 's/<\('$int'[1-9]\)>/__typeof (\1v)/g'`); \\'; \\"

    # generate call the primtive system call, optionally wrapping bounds
    # around the result if the signature's return keyletter is `b'.
    echo "	 echo '  return `echo $rtn |
	    sed -e 's/<b0>/BOUNDED_N (/' \
		-e 's/<.0>//'`($callname) (`echo $arglist | \
	    sed -e 's/<\(a[1-9]\)>/__ptrvalue (\1a)/g' \
		-e 's/<\(n[1-9]\)>, <\(V[1-9]\)>/\1a, CHECK_N_PAGES (\2a, \1a)/g' \
		-e 's/<\(b[1-9]\)>, <\(n[1-9]\)>/CHECK_N (\1a, \2a), \2a/g' \
		-e 's/<\(b[1-9]\)>, <\(N[1-9]\)>/CHECK_N (\1a, *CHECK_1 (\2a)), __ptrvalue (\2a)/g' \
		-e 's/<\(B[1-9]\)>, <\(n[1-9]\)>/CHECK_N_NULL_OK (\1a, \2a), \2a/g' \
		-e 's/<\(B[1-9]\)>, <\(N[1-9]\)>/CHECK_N_NULL_OK (\1a, *CHECK_1 (\2a)), __ptrvalue (\2a)/g' \
		-e 's/<\(f[1-9]\)>/CHECK_N (\1a, 2)/g' \
		-e 's/<\(i[1-9]\)>, <\(F[1-9]\)>/\1a, CHECK_FCNTL (\2a, \1a)/g' \
		-e 's/<\(i[1-9]\)>, <\(I[1-9]\)>/\1a, CHECK_IOCTL (\2a, \1a)/g' \
		-e 's/<\(p[1-9]\)>/CHECK_1 (\1a)/g' \
		-e 's/<\([PW][1-9]\)>/CHECK_1_NULL_OK (\1a)/g' \
		-e 's/<\(s[1-9]\)>/CHECK_STRING (\1a)/g' \
		-e 's/<\(S[1-9]\)>/CHECK_STRING_NULL_OK (\1a)/g' \
		-e 's/<\([ivn][1-9]\)>/\1a/g'`)`echo $rtn $args |
	    sed -e 's/<b0>.*<\(n[1-9]\)>.*/, \1a)/' \
		-e 's/<.0>.*//'`; \\'; \\"

    echo "	 echo '} \\'; \\"

    echo "	 echo 'libc_hidden_def (BP_SYM ($strong)) \\'; \\"

    # generate thunk aliases
    for name in $nv_weak; do
      echo "	 echo 'weak_alias (BP_SYM ($strong), BP_SYM ($name)) \\'; \\"
      echo "	 echo 'libc_hidden_weak (BP_SYM ($name)) \\'; \\"
    done

    # wrap up
    echo "\
	 echo ''; \\
	 echo '#include <bp-thunks.h>'; \\
	) | \$(COMPILE.c) -x c -o \$@ -"
### Use this for debugging intermediate output:
### 	) >\$(@:.ob=.c)
### 	\$(subst -c,-E,\$(COMPILE.c)) -o \$(@:.ob=.ib) \$(@:.ob=.c)
### 	\$(COMPILE.c) -x cpp-output -o \$@ \$(@:.ob=.ib)"
    echo endif
    ;;
  esac

done