1# Copyright (C) 2010-2020 Free Software Foundation, Inc. 2 3# This program is free software; you can redistribute it and/or modify 4# it under the terms of the GNU General Public License as published by 5# the Free Software Foundation; either version 3 of the License, or 6# (at your option) any later version. 7# 8# This program is distributed in the hope that it will be useful, 9# but WITHOUT ANY WARRANTY; without even the implied warranty of 10# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 11# GNU General Public License for more details. 12# 13# You should have received a copy of the GNU General Public License 14# along with this program. If not, see <http://www.gnu.org/licenses/>. 15 16# Return nul-terminated string read from section SECTION of EXEC. Return "" 17# if no such section or nul-terminated string was found. Function is useful 18# for sections ".interp" or ".gnu_debuglink". 19 20proc section_get {exec section} { 21 global subdir 22 set tmp [standard_output_file section_get.tmp] 23 set objcopy_program [gdb_find_objcopy] 24 25 set command "exec $objcopy_program -O binary --set-section-flags $section=A --change-section-address $section=0 -j $section $exec $tmp" 26 verbose -log "command is $command" 27 set result [catch $command output] 28 verbose -log "result is $result" 29 verbose -log "output is $output" 30 if {$result == 1} { 31 return "" 32 } 33 set fi [open $tmp] 34 fconfigure $fi -translation binary 35 set data [read $fi] 36 close $fi 37 file delete $tmp 38 # .interp has size $len + 1 but .gnu_debuglink contains garbage after \000. 39 set len [string first \000 $data] 40 if {$len < 0} { 41 verbose -log "section $section not found" 42 return "" 43 } 44 set retval [string range $data 0 [expr $len - 1]] 45 verbose -log "section $section is <$retval>" 46 return $retval 47} 48 49# Resolve symlinks. 50 51proc symlink_resolve {file} { 52 set loop 0 53 while {[file type $file] == "link"} { 54 set target [file readlink $file] 55 if {[file pathtype $target] == "relative"} { 56 set src2 [file dirname $file]/$target 57 } else { 58 set src2 $target 59 } 60 verbose -log "Resolved symlink $file targetting $target as $src2" 61 set file $src2 62 63 set loop [expr $loop + 1] 64 if {$loop > 30} { 65 fail "looping symlink resolution for $file" 66 return "" 67 } 68 } 69 return $file 70} 71 72# Copy SRC to DEST, resolving any symlinks in SRC. Return nonzero iff 73# the copy was succesful. 74# 75# This function is guaranteed to never raise any exception, even when the copy 76# fails. 77 78proc file_copy {src dest} { 79 set src [symlink_resolve $src] 80 # Test name would contain unstable directory name for symlink-unresolved 81 # $src. 82 set test "copy [file tail $src] to [file tail $dest]" 83 set command "file copy -force -- $src $dest" 84 verbose -log "command is $command" 85 if [catch $command] { 86 fail $test 87 return 0 88 } else { 89 pass $test 90 return 1 91 } 92} 93 94# Wrap function build_executable so that the resulting executable is fully 95# self-sufficient (without dependencies on system libraries). Parameter 96# INTERP may be used to specify a loader (ld.so) to be used that is 97# different from the default system one. INTERP can be set to "no" if no ld.so 98# copy should be made. Libraries on which the executable depends are copied 99# into directory DIR. Default DIR value to 100# `${objdir}/${subdir}/${EXECUTABLE}.d'. 101# 102# In case of success, return a string containing the arguments to be used 103# in order to perform a prelink of the executable obtained. Return the 104# empty string in case of failure. 105# 106# This can be useful when trying to prelink an executable which might 107# depend on system libraries. To properly prelink an executable, all 108# of its dynamically linked libraries must be prelinked as well. If 109# the executable depends on some system libraries, we may not have 110# sufficient write priviledges on these files to perform the prelink. 111# This is why we make a copy of these shared libraries, and link the 112# executable against these copies instead. 113# 114# Function recognizes only libraries listed by `ldd' after 115# its ` => ' separator. That means $INTERP and any libraries not being linked 116# with -Wl,-soname,NAME.so are not copied. 117 118proc build_executable_own_libs {testname executable sources options {interp ""} {dir ""}} { 119 global subdir 120 121 if { ![isnative] } { 122 error "This proc can be only used for native target." 123 } 124 125 if {[build_executable $testname $executable $sources $options] == -1} { 126 return "" 127 } 128 set binfile [standard_output_file ${executable}] 129 130 set ldd [gdb_find_ldd] 131 set command "$ldd $binfile" 132 set test "ldd $executable" 133 set result [catch "exec $command" output] 134 verbose -log "result of $command is $result" 135 verbose -log "output of $command is $output" 136 if {$result != 0 || $output == ""} { 137 fail $test 138 } else { 139 pass $test 140 } 141 142 # gdb testsuite will put there also needless -lm. 143 set test "$test output contains libs" 144 set libs [regexp -all -inline -line {^.* => (/[^ ]+).*$} $output] 145 if {[llength $libs] == 0} { 146 fail $test 147 } else { 148 pass $test 149 } 150 151 if {$dir == ""} { 152 set dir ${binfile}.d 153 } 154 file delete -force -- $dir 155 file mkdir $dir 156 157 if {$interp == ""} { 158 set interp_system [section_get $binfile .interp] 159 if {$interp_system == ""} { 160 fail "$test could not find .interp" 161 } else { 162 set interp ${dir}/[file tail $interp_system] 163 file_copy $interp_system $interp 164 } 165 } 166 if {$interp == "no"} { 167 set interp "" 168 } 169 170 set dests {} 171 foreach {trash abspath} $libs { 172 set dest "$dir/[file tail $abspath]" 173 file_copy $abspath $dest 174 lappend dests $dest 175 } 176 177 # Do not lappend it so that "-rpath $dir" overrides any possible "-rpath"s 178 # specified by the caller to be able to link it for ldd" above. 179 set options [linsert $options 0 "ldflags=-Wl,-rpath,$dir"] 180 if {$interp != ""} { 181 set options [linsert $options 0 "ldflags=-Wl,--dynamic-linker,$interp"] 182 } 183 184 if {[build_executable $testname $executable $sources $options] == -1} { 185 return "" 186 } 187 188 set prelink_args "--ld-library-path=$dir $binfile [concat $dests]" 189 if {$interp != ""} { 190 set prelink_args "--dynamic-linker=$interp $prelink_args $interp" 191 } 192 return $prelink_args 193} 194 195# Unprelink ARG. Reported test name can be specified by NAME. Return non-zero 196# on success, zero on failure. 197 198proc prelink_no {arg {name {}}} { 199 if {$name == ""} { 200 set name [file tail $arg] 201 } 202 set test "unprelink $name" 203 set command "exec /usr/sbin/prelink -uN $arg" 204 verbose -log "command is $command" 205 set result [catch $command output] 206 verbose -log "result is $result" 207 verbose -log "output is $output" 208 if {$result == 1 && [regexp {^(couldn't execute "/usr/sbin/prelink[^\r\n]*": no such file or directory\n?)*$} $output]} { 209 # Without prelink, at least verify that all the binaries do not 210 # contain the ".gnu.prelink_undo" section (which would mean that they 211 # have already been prelinked). 212 set test "$test (missing /usr/sbin/prelink)" 213 foreach bin [split $arg] { 214 if [string match "-*" $bin] { 215 # Skip prelink options. 216 continue 217 } 218 set readelf_program [gdb_find_readelf] 219 set command "exec $readelf_program -WS $bin" 220 verbose -log "command is $command" 221 set result [catch $command output] 222 verbose -log "result is $result" 223 verbose -log "output is $output" 224 if {$result != 0 || [string match {* .gnu.prelink_undo *} $output]} { 225 fail "$test ($bin is already prelinked)" 226 return 0 227 } 228 } 229 pass $test 230 return 1 231 } 232 if {$result == 0 && $output == ""} { 233 verbose -log "$name has been now unprelinked" 234 set command "exec /usr/sbin/prelink -uN $arg" 235 verbose -log "command is $command" 236 set result [catch $command output] 237 verbose -log "result is $result" 238 verbose -log "output is $output" 239 } 240 # Last line does miss the trailing \n. There can be multiple such messages 241 # as ARG may list multiple files. 242 if {$result == 1 && [regexp {^([^\r\n]*prelink[^\r\n]*: [^ ]* does not have .gnu.prelink_undo section\n?)*$} $output]} { 243 pass $test 244 return 1 245 } else { 246 fail $test 247 return 0 248 } 249} 250 251# Prelink ARG. Reported test name can be specified by NAME. Return non-zero 252# on success, zero on failure. 253 254proc prelink_yes {arg {name ""}} { 255 if {$name == ""} { 256 set name [file tail $arg] 257 } 258 259 # Try to unprelink it first so that, if it has been already prelinked 260 # before, we get a different address now, making the new result unaffected 261 # by any previous prelinking. 262 if ![prelink_no $arg "$name pre-unprelink"] { 263 return 0 264 } 265 266 set test "prelink $name" 267 268 # `--no-exec-shield' is for i386, where prelink in the exec-shield mode is 269 # forced to push all the libraries tight together, in order to fit into 270 # the first two memory areas (either the ASCII Shield area or at least 271 # below the executable). If the prelink was performed in exec-shield 272 # mode, prelink could have no choice on how to randomize the single new 273 # unprelinked library address without wasting space in the first one/two 274 # memory areas. In such case prelink could place $ARG repeatedly at the 275 # same place and we could have false prelink results on 276 # gdb.base/prelink.exp and others. To prevent this from happening, we use 277 # the --no-exec-shield switch. This may have some consequences in terms 278 # of security, but we do not care in our case. 279 280 set command "exec /usr/sbin/prelink -qNR --no-exec-shield $arg" 281 282 verbose -log "command is $command" 283 set result [catch $command output] 284 verbose -log "result is $result" 285 verbose -log "output is $output" 286 if {$result == 1 && [regexp {^(couldn't execute "/usr/sbin/prelink[^\r\n]*": no such file or directory\n?)*$} $output]} { 287 set test "$test (missing /usr/sbin/prelink)" 288 289 # We could not find prelink. We could check whether $args is already 290 # prelinked but we don't, because: 291 # - It is unlikely that someone uninstalls prelink after having 292 # prelinked the system ld.so; 293 # - We still cannot change its prelinked address. 294 # Therefore, we just skip the test. 295 296 xfail $test 297 return 0 298 } 299 if {$result == 1 && [regexp {DWARF [^\r\n]* unhandled} $output]} { 300 # Prelink didn't understand the version of dwarf present. 301 unsupported "$test (dwarf version unhandled)" 302 return 0 303 } 304 if {$result == 0 && $output == ""} { 305 pass $test 306 return 1 307 } elseif {$result == 1 \ 308 && [string match -nocase "*: Not enough room to add .dynamic entry" $output]} { 309 # Linker should have reserved some entries for prelink. 310 xfail $test 311 return 0 312 } else { 313 fail $test 314 return 0 315 } 316} 317