gdb/testsuite/gdb.base/gnu-ifunc.exp

   1 # Copyright (C) 2009-2022 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 if {[skip_shlib_tests]} {
  17     return 0
  18 }
  19
  20 if {[skip_ifunc_tests]} {
  21     return 0
  22 }
  23
  24 standard_testfile .c
  25 set staticexecutable ${testfile}-static
  26 set staticbinfile [standard_output_file ${staticexecutable}]
  27
  28 set libfile "${testfile}-lib"
  29 set libsrc ${libfile}.c
  30
  31 set final_file "${testfile}-final"
  32 set final_src ${final_file}.c
  33
  34 if [get_compiler_info] {
  35     return -1
  36 }
  37
  38 # Return the binary suffix appended to program and library names to
  39 # make each testcase variant unique.
  40 proc make_binsuffix {resolver_attr resolver_debug final_debug} {
  41     return "$resolver_attr-$resolver_debug-$final_debug"
  42 }
  43
  44 # Compile the testcase.  RESOLVER_ATTR is true if we're testing with
  45 # an ifunc resolver that has a different name from the user symbol,
  46 # specified with GCC's __attribute__ ifunc.  RESOLVER_DEBUG is true
  47 # iff the resolver was compiled with debug info.  FINAL_DEBUG is true
  48 # iff the target function was compiled with debug info.
  49 proc build {resolver_attr resolver_debug final_debug} {
  50     global srcdir subdir srcfile binfile
  51     global libsrc lib_so libfile
  52     global exec_opts executable
  53     global hex gdb_prompt
  54     global final_file final_src
  55
  56     set suffix [make_binsuffix $resolver_attr $resolver_debug $final_debug]
  57
  58     set lib_so [standard_output_file ${libfile}-$suffix.so]
  59     # $lib_o must not have {debug}, it would override the STT_GNU_IFUNC ELF markers.
  60     set lib_o [standard_output_file ${libfile}-$suffix.o]
  61
  62     set exec_opts [list debug shlib=$lib_so]
  63
  64     set lib_opts {}
  65     set final_opts {}
  66
  67     # Force lazy binding so we don't resolve everything at process startup.
  68     lappend exec_opts "additional_flags=-Wl,-z,lazy"
  69     lappend lib_opts "additional_flags=-Wl,-z,lazy"
  70
  71     if {$resolver_attr} {
  72         lappend lib_opts "additional_flags=-DIFUNC_RESOLVER_ATTR"
  73     }
  74
  75     if {$resolver_debug} {
  76         lappend lib_opts "debug"
  77     }
  78
  79     if {$final_debug} {
  80         lappend final_opts "debug"
  81     }
  82
  83     set final_o [standard_output_file $final_file-$suffix.o]
  84
  85     if { [gdb_compile_shlib ${srcdir}/${subdir}/$libsrc \
  86               $lib_so $lib_opts] != ""
  87          || [gdb_compile ${srcdir}/${subdir}/$final_src \
  88                  $final_o object $final_opts] != ""
  89          || [gdb_compile [list ${srcdir}/${subdir}/$srcfile $final_o] \
  90                  $binfile-$suffix executable $exec_opts] != ""} {
  91         untested "failed to compile testcase"
  92         return 0
  93     }
  94
  95     return 1
  96 }
  97
  98 # Test setting a breakpoint on a ifunc function before and after the
  99 # ifunc is resolved.  For the description of RESOLVER_ATTR,
 100 # RESOLVER_DEBUG and FINAL_DEBUG, see the "build" procedure above.
 101 proc_with_prefix set-break {resolver_attr resolver_debug final_debug} {
 102     global binfile libfile lib_so
 103     global hex decimal
 104     global gdb_prompt
 105
 106     set suffix [make_binsuffix $resolver_attr $resolver_debug $final_debug]
 107
 108     set lib_so [standard_output_file ${libfile}-$suffix.so]
 109     clean_restart $binfile-$suffix
 110     gdb_load_shlib ${lib_so}
 111
 112     if ![runto_main] then {
 113         return 1
 114     }
 115
 116     gdb_breakpoint [gdb_get_line_number "break-at-call"]
 117     gdb_continue_to_breakpoint "break-at-call" ".*break-at-call.*"
 118
 119     set ws "\[ \t\]+"
 120     set dot "\\.?"
 121
 122     if {$resolver_attr} {
 123         set gnu_ifunc_resolver "gnu_ifunc_resolver"
 124     } else {
 125         set gnu_ifunc_resolver "gnu_ifunc"
 126     }
 127
 128     if {!$resolver_debug} {
 129         set gnu_ifunc_resolver "${dot}${gnu_ifunc_resolver}"
 130     }
 131
 132     if {!$final_debug} {
 133         set final "${dot}final"
 134     } else {
 135         set final "final"
 136     }
 137
 138     with_test_prefix "before resolving" {
 139         delete_breakpoints
 140         gdb_test "break gnu_ifunc" \
 141             "Breakpoint $decimal at gnu-indirect-function resolver at $hex"
 142         gdb_test "info breakpoints" \
 143             "$decimal${ws}STT_GNU_IFUNC resolver${ws}keep${ws}y${ws}$hex <${gnu_ifunc_resolver}>"
 144
 145         # Make the breakpoint conditional on a condition that always
 146         # fails.  This is so that when the ifunc-resolver breakpoint
 147         # triggers, GDB resumes the program immediately.
 148         gdb_test_no_output "condition \$bpnum 0"
 149     }
 150
 151     global final_src
 152
 153     with_test_prefix "resolve" {
 154         gdb_breakpoint [gdb_get_line_number "break-at-exit"]
 155         gdb_continue_to_breakpoint "break-at-exit" ".*break-at-exit.*"
 156     }
 157
 158     with_test_prefix "after resolving" {
 159         if {!$final_debug} {
 160             # Set a breakpoint both at the ifunc, and at the ifunc's
 161             # target.  GDB should resolve both to the same address.
 162             # Start with the ifunc's target.
 163             set addr "-"
 164             set test "break final"
 165             # Extract the address without the leading "0x", because
 166             # addresses in "info break" output include leading 0s
 167             # (like "0x0000ADDR").
 168             set hex_number {[0-9a-fA-F][0-9a-fA-F]*}
 169             gdb_test_multiple $test $test {
 170                 -re "Breakpoint .* at 0x($hex_number)\r\n$gdb_prompt $" {
 171                     set addr $expect_out(1,string)
 172                     pass $test
 173                 }
 174             }
 175
 176             # Now set a break at the ifunc.
 177             gdb_test "break gnu_ifunc" "Breakpoint .* at 0x$addr"
 178             set location "$decimal${ws}breakpoint${ws}keep${ws}y${ws}0x0*$addr${ws}<${final}\\+.*>"
 179         } else {
 180             set lineno -1
 181             set test "break final"
 182             gdb_test_multiple $test $test {
 183                 -re "Breakpoint .* at $hex: file .*$final_src, line ($decimal)\\.\r\n$gdb_prompt $" {
 184                     set lineno $expect_out(1,string)
 185                     pass $test
 186                 }
 187             }
 188             gdb_test "break gnu_ifunc" "Breakpoint .* at $hex: file .*$final_src, line $lineno\\."
 189             set location "$decimal${ws}breakpoint${ws}keep${ws}y${ws}$hex in final at .*$final_src:$lineno"
 190         }
 191
 192         # The first location here is for the breakpoint that was set
 193         # before the ifunc was resolved.  It should be resolved by
 194         # now, and it should have the exact same address/line as the
 195         # other two locations.
 196         gdb_test "info breakpoints" "$location\r\n.*$location\r\n$location"
 197     }
 198 }
 199
 200 # Misc GNU ifunc tests.  For the description of RESOLVER_ATTR,
 201 # RESOLVER_DEBUG and FINAL_DEBUG, see the "build" procedure above.
 202 proc misc_tests {resolver_attr resolver_debug final_debug} {
 203     global srcdir subdir srcfile binfile
 204     global libsrc lib_so libfile
 205     global exec_opts executable
 206     global hex gdb_prompt
 207     global final_file final_src
 208
 209     set suffix [make_binsuffix $resolver_attr $resolver_debug $final_debug]
 210
 211     if {$resolver_attr} {
 212         set gnu_ifunc_resolver "gnu_ifunc_resolver"
 213     } else {
 214         set gnu_ifunc_resolver "gnu_ifunc"
 215     }
 216
 217     set dot "\\.?"
 218
 219     if {!$resolver_debug} {
 220         set gnu_ifunc_resolver "${dot}${gnu_ifunc_resolver}"
 221     }
 222
 223     if {!$final_debug} {
 224         set final "${dot}final"
 225     } else {
 226         set final "final"
 227     }
 228
 229     # Start with a fresh gdb.
 230
 231     clean_restart $binfile-$suffix
 232     gdb_load_shlib ${lib_so}
 233
 234     if ![runto_main] then {
 235         return 1
 236     }
 237
 238     # The "if" condition is artifical to test regression of a former patch.
 239     gdb_breakpoint "[gdb_get_line_number "break-at-nextcall"] if i && (int) gnu_ifunc (i) != 42"
 240
 241     gdb_breakpoint [gdb_get_line_number "break-at-call"]
 242     gdb_continue_to_breakpoint "break-at-call" ".*break-at-call.*"
 243
 244     # Test GDB will automatically indirect the call.
 245
 246     if {!$resolver_debug && !$final_debug} {
 247         gdb_test "p gnu_ifunc()" \
 248             "'${dot}final' has unknown return type; cast the call to its declared return type"
 249         gdb_test "p gnu_ifunc (3)" \
 250             "'${dot}final' has unknown return type; cast the call to its declared return type"
 251         gdb_test "p (int) gnu_ifunc (3)" " = 4"
 252     } else {
 253         gdb_test "p gnu_ifunc()" "Too few arguments in function call\\."
 254         gdb_test "p gnu_ifunc (3)" " = 4"
 255     }
 256
 257     # Test that the resolver received its argument.
 258
 259     set actual_hwcap "0x0"
 260     set test "info auxv"
 261     gdb_test_multiple $test $test {
 262         -re "\r\n\\d+\\s+AT_HWCAP\[^\r\n\]+($hex)\r\n.*$gdb_prompt $" {
 263             set actual_hwcap $expect_out(1,string)
 264         }
 265         -re ".*$gdb_prompt $" {
 266             pass "$test (no HWCAP)"
 267         }
 268     }
 269
 270     gdb_test "p/x resolver_hwcap" "= $actual_hwcap" "resolver received HWCAP"
 271
 272     # Test GDB will skip the gnu_ifunc resolver on first call.
 273
 274     # Even if the resolver has debug info, stepping into an ifunc call
 275     # should skip the resolver.
 276     if {!$final_debug} {
 277         # Make GDB stop stepping even if it steps into a function with
 278         # no debug info.
 279         gdb_test_no_output "set step-mode on"
 280         gdb_test "step" "$hex in ${dot}final \\\(\\\)"
 281     } else {
 282         gdb_test "step" "\r\nfinal .*"
 283     }
 284
 285     # Test GDB will not break before the final chosen implementation.
 286
 287     # Also test a former patch regression:
 288     # Continuing.
 289     # Error in testing breakpoint condition:
 290     # Attempt to take address of value not located in memory.
 291     #
 292     # Breakpoint 2, main () at ./gdb.base/gnu-ifunc.c:33
 293
 294     gdb_test "continue" \
 295         "Continuing.\r\n\r\nBreakpoint .* (at|in) .*break-at-nextcall.*" \
 296         "continue to break-at-nextcall"
 297
 298     gdb_breakpoint "gnu_ifunc"
 299
 300     gdb_continue_to_breakpoint "nextcall gnu_ifunc"
 301
 302     gdb_test "frame" \
 303         "#0 +(0x\[0-9a-f\]+ in +)?${final} \\(.*" "nextcall gnu_ifunc skipped"
 304
 305     # Check any commands not doing an inferior call access the address of the
 306     # STT_GNU_IFUNC resolver, not the target function.
 307
 308     if {[istarget powerpc64-*] && [is_lp64_target]} {
 309         # With only minimal symbols GDB provides the function descriptors.  With
 310         # full debug info the function code would be displayed.
 311     }
 312
 313     gdb_test "p gnu_ifunc" \
 314         " = {<text gnu-indirect-function variable, no debug info>} 0x\[0-9a-f\]+ <${gnu_ifunc_resolver}>" \
 315         "p gnu_ifunc executing"
 316     gdb_test "info sym gnu_ifunc" \
 317         "${gnu_ifunc_resolver} in section .*" \
 318         "info sym gnu_ifunc executing"
 319
 320     set test "info addr gnu_ifunc"
 321     if {!$resolver_attr && $resolver_debug} {
 322         gdb_test_multiple $test $test {
 323             -re "Symbol \"gnu_ifunc\" is a function at address (0x\[0-9a-f\]+).*$gdb_prompt $" {
 324                 pass $test
 325             }
 326         }
 327     } else {
 328         gdb_test_multiple $test $test {
 329             -re "Symbol \"gnu_ifunc\" is at (0x\[0-9a-f\]+) in .*$gdb_prompt $" {
 330                 pass $test
 331             }
 332         }
 333     }
 334     gdb_test "info sym $expect_out(1,string)" \
 335         "${gnu_ifunc_resolver} in section .*" \
 336         "info sym <gnu_ifunc-address>"
 337
 338     # Test calling the resolver directly instead of the ifunc symbol.
 339     # Can only do that if the ifunc and the ifunc resolver have
 340     # different names.
 341     if {$resolver_attr} {
 342         if {$resolver_debug} {
 343             if {[istarget powerpc64-*] && [is_lp64_target]} {
 344                 gdb_test "p gnu_ifunc_resolver(0)" \
 345                     " = \\(int \\(\\*\\)\\(int\\)\\) @$hex: $hex <${final}>"
 346             } else {
 347                 gdb_test "p gnu_ifunc_resolver(0)" \
 348                     " = \\(int \\(\\*\\)\\(int\\)\\) $hex <final>"
 349             }
 350         } else {
 351             gdb_test "p gnu_ifunc_resolver(0)" \
 352                 "'${gnu_ifunc_resolver}' has unknown return type; cast the call to its declared return type"
 353             gdb_test "p (void *) gnu_ifunc_resolver(0)" \
 354                 " = \\(void \\*\\) $hex <${final}>"
 355         }
 356     }
 357 }
 358
 359 # Test all the combinations of:
 360 #
 361 # - An ifunc resolver with the same name as the ifunc symbol vs an
 362 #   ifunc resolver with a different name as the ifunc symbol.
 363 #
 364 # - ifunc resolver compiled with and without debug info.  This ensures
 365 #   that GDB understands that a function not a regular function by
 366 #   looking at the STT_GNU_IFUNC type in the elf symbols.  DWARF has
 367 #   no way to express the STT_GNU_IFUNC type.
 368 #
 369 # - ifunc target function (resolved) compiled with and without debug
 370 #   info.
 371 foreach_with_prefix resolver_attr {0 1} {
 372     foreach_with_prefix resolver_debug {0 1} {
 373         foreach_with_prefix final_debug {0 1} {
 374             if { [build $resolver_attr $resolver_debug $final_debug] != 0 } {
 375                 misc_tests $resolver_attr $resolver_debug $final_debug
 376                 set-break $resolver_attr $resolver_debug $final_debug
 377             }
 378         }
 379     }
 380 }
 381
 382 # Test statically linked ifunc resolving during inferior start.
 383 # https://bugzilla.redhat.com/show_bug.cgi?id=624967
 384
 385 with_test_prefix "static" {
 386     # Compile $staticbinfile separately as it may exit on error
 387     # (ld/12595).
 388
 389     set lib_o [standard_output_file ${libfile}.o]
 390     set final_o [standard_output_file ${final_file}.o]
 391     if { [gdb_compile ${srcdir}/${subdir}/$libsrc $lib_o object {}] != ""
 392          || [gdb_compile ${srcdir}/${subdir}/$final_src $final_o object {}] != ""
 393          || [gdb_compile "${srcdir}/${subdir}/$srcfile $lib_o $final_o" \
 394                  $staticbinfile executable {debug}] != "" } {
 395         untested "failed to compile second testcase"
 396         return -1
 397     }
 398
 399     clean_restart $staticexecutable
 400
 401     gdb_breakpoint "gnu_ifunc"
 402     gdb_breakpoint "main"
 403     gdb_run_cmd
 404     gdb_test "" "Breakpoint \[0-9\]*, main .*" "static gnu_ifunc"
 405 }