Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

libdwarves is missing ELF symbol versions #13

Open
jengelh opened this issue Oct 2, 2020 · 0 comments
Open

libdwarves is missing ELF symbol versions #13

jengelh opened this issue Oct 2, 2020 · 0 comments

Comments

@jengelh
Copy link

jengelh commented Oct 2, 2020

Some distributions put libdwarves.so.1 and the programs (pahole et al) in separate packages.
Due to a lack of ELF symbol versioning in libdwarves.so.1, it is possible to then install the distro pahole-1.18 package while keeping libdwarves1 at 1.17. As a result, pahole no longer works.

» pahole /bin/ls
pahole: symbol lookup error: pahole: undefined symbol: tabs

ELF symvers would easily solve this, as rpmbuild picks those up and can generate appropriate dependencies for rpm packages.

acmel added a commit that referenced this issue Jul 8, 2021
…() calls

As this ends up racing on a tsearch() call, probably for some libdw
cache that gets updated/lookedup in concurrent pahole threads (-j N).

This cures the following, a patch for libdw will be cooked up and sent.

  (gdb) run -j -I -F dwarf vmlinux > /dev/null
  Starting program: /var/home/acme/git/pahole/build/pahole -j -I -F dwarf vmlinux > /dev/null
  warning: Expected absolute pathname for libpthread in the inferior, but got .gnu_debugdata for /lib64/libpthread.so.0.
  warning: File "/usr/lib64/libthread_db-1.0.so" auto-loading has been declined by your `auto-load safe-path' set to "$debugdir:$datadir/auto-load".
  warning: Unable to find libthread_db matching inferior's thread library, thread debugging will not be available.
  [New LWP 844789]
  [New LWP 844790]
  [New LWP 844791]
  [New LWP 844792]
  [New LWP 844793]
  [New LWP 844794]
  [New LWP 844795]
  [New LWP 844796]
  [New LWP 844797]
  [New LWP 844798]
  [New LWP 844799]
  [New LWP 844800]
  [New LWP 844801]
  [New LWP 844802]
  [New LWP 844803]
  [New LWP 844804]
  [New LWP 844805]
  [New LWP 844806]
  [New LWP 844807]
  [New LWP 844808]
  [New LWP 844809]
  [New LWP 844810]
  [New LWP 844811]
  [New LWP 844812]
  [New LWP 844813]
  [New LWP 844814]

  Thread 2 "pahole" received signal SIGSEGV, Segmentation fault.
  [Switching to LWP 844789]
  0x00007ffff7dfa321 in ?? () from /lib64/libc.so.6
  (gdb) bt
  #0  0x00007ffff7dfa321 in ?? () from /lib64/libc.so.6
  #1  0x00007ffff7dfa4bb in ?? () from /lib64/libc.so.6
  #2  0x00007ffff7f5eaa6 in __libdw_getsrclines (dbg=0x4a7f90, debug_line_offset=10383710, comp_dir=0x7ffff3c29f01 "/var/home/acme/git/build/v5.13.0-rc6+", address_size=address_size@entry=8, linesp=linesp@entry=0x7fffcfe04ba0, filesp=filesp@entry=0x7fffcfe04ba8)
      at dwarf_getsrclines.c:1129
  #3  0x00007ffff7f5ed14 in dwarf_getsrclines (cudie=cudie@entry=0x7fffd210caf0, lines=lines@entry=0x7fffd210cac0, nlines=nlines@entry=0x7fffd210cac8) at dwarf_getsrclines.c:1213
  #4  0x00007ffff7f64883 in dwarf_decl_file (die=<optimized out>) at dwarf_decl_file.c:66
  #5  0x0000000000425f24 in tag__init (tag=0x7fff0421b710, cu=0x7fffcc001e40, die=0x7fffd210cd30) at /var/home/acme/git/pahole/dwarf_loader.c:476
  #6  0x00000000004262ec in namespace__init (namespace=0x7fff0421b710, die=0x7fffd210cd30, cu=0x7fffcc001e40, conf=0x475600 <conf_load>) at /var/home/acme/git/pahole/dwarf_loader.c:576
  #7  0x00000000004263ac in type__init (type=0x7fff0421b710, die=0x7fffd210cd30, cu=0x7fffcc001e40, conf=0x475600 <conf_load>) at /var/home/acme/git/pahole/dwarf_loader.c:595
  #8  0x00000000004264d1 in type__new (die=0x7fffd210cd30, cu=0x7fffcc001e40, conf=0x475600 <conf_load>) at /var/home/acme/git/pahole/dwarf_loader.c:614
  #9  0x0000000000427ba6 in die__create_new_typedef (die=0x7fffd210cd30, cu=0x7fffcc001e40, conf=0x475600 <conf_load>) at /var/home/acme/git/pahole/dwarf_loader.c:1212
  #10 0x0000000000428df5 in __die__process_tag (die=0x7fffd210cd30, cu=0x7fffcc001e40, top_level=1, fn=0x45cee0 <__FUNCTION__.10> "die__process_unit", conf=0x475600 <conf_load>) at /var/home/acme/git/pahole/dwarf_loader.c:1823
  #11 0x0000000000428ea1 in die__process_unit (die=0x7fffd210cd30, cu=0x7fffcc001e40, conf=0x475600 <conf_load>) at /var/home/acme/git/pahole/dwarf_loader.c:1848
  #12 0x0000000000429e45 in die__process (die=0x7fffd210ce20, cu=0x7fffcc001e40, conf=0x475600 <conf_load>) at /var/home/acme/git/pahole/dwarf_loader.c:2311
  #13 0x0000000000429ecb in die__process_and_recode (die=0x7fffd210ce20, cu=0x7fffcc001e40, conf=0x475600 <conf_load>) at /var/home/acme/git/pahole/dwarf_loader.c:2326
  #14 0x000000000042a9d6 in dwarf_cus__create_and_process_cu (dcus=0x7fffffffddc0, cu_die=0x7fffd210ce20, pointer_size=8 '\b') at /var/home/acme/git/pahole/dwarf_loader.c:2644
  #15 0x000000000042ab28 in dwarf_cus__process_cu_thread (arg=0x7fffffffddc0) at /var/home/acme/git/pahole/dwarf_loader.c:2687
  #16 0x00007ffff7ed6299 in start_thread () from /lib64/libpthread.so.0
  #17 0x00007ffff7dfe353 in ?? () from /lib64/libc.so.6
  (gdb)
  (gdb) fr 2
  1085
  (gdb) list files_lines_compare
  1086    static int
  1087    files_lines_compare (const void *p1, const void *p2)
  1088    {
  1089	  const struct files_lines_s *t1 = p1;
  1090	  const struct files_lines_s *t2 = p2;
  1091
  1092	  if (t1->debug_line_offset < t2->debug_line_offset)
  (gdb)
  1093        return -1;
  1094	  if (t1->debug_line_offset > t2->debug_line_offset)
  1095        return 1;
  1096
  1097	  return 0;
  1098    }
  1099
  1100    int
  1101    internal_function
  1102    __libdw_getsrclines (Dwarf *dbg, Dwarf_Off debug_line_offset,
  (gdb) list __libdw_getsrclines
  1100    int
  1101    internal_function
  1102    __libdw_getsrclines (Dwarf *dbg, Dwarf_Off debug_line_offset,
  1103                         const char *comp_dir, unsigned address_size,
  1104                         Dwarf_Lines **linesp, Dwarf_Files **filesp)
  1105    {
  1106	  struct files_lines_s fake = { .debug_line_offset = debug_line_offset };
  1107	  struct files_lines_s **found = tfind (&fake, &dbg->files_lines,
  1108                                            files_lines_compare);
  1109	  if (found == NULL)
  (gdb)
  1110        {
  1111          Elf_Data *data = __libdw_checked_get_data (dbg, IDX_debug_line);
  1112          if (data == NULL
  1113              || __libdw_offset_in_section (dbg, IDX_debug_line,
  1114                                            debug_line_offset, 1) != 0)
  1115            return -1;
  1116
  1117          const unsigned char *linep = data->d_buf + debug_line_offset;
  1118          const unsigned char *lineendp = data->d_buf + data->d_size;
  1119
  (gdb)
  1120          struct files_lines_s *node = libdw_alloc (dbg, struct files_lines_s,
  1121                                                    sizeof *node, 1);
  1122
  1123          if (read_srclines (dbg, linep, lineendp, comp_dir, address_size,
  1124                             &node->lines, &node->files) != 0)
  1125            return -1;
  1126
  1127          node->debug_line_offset = debug_line_offset;
  1128
  1129          found = tsearch (node, &dbg->files_lines, files_lines_compare);
  (gdb)

Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
acmel added a commit that referenced this issue Jul 27, 2021
…() calls

As this ends up racing on a tsearch() call, probably for some libdw
cache that gets updated/lookedup in concurrent pahole threads (-j N).

This cures the following, a patch for libdw will be cooked up and sent.

  (gdb) run -j -I -F dwarf vmlinux > /dev/null
  Starting program: /var/home/acme/git/pahole/build/pahole -j -I -F dwarf vmlinux > /dev/null
  warning: Expected absolute pathname for libpthread in the inferior, but got .gnu_debugdata for /lib64/libpthread.so.0.
  warning: File "/usr/lib64/libthread_db-1.0.so" auto-loading has been declined by your `auto-load safe-path' set to "$debugdir:$datadir/auto-load".
  warning: Unable to find libthread_db matching inferior's thread library, thread debugging will not be available.
  [New LWP 844789]
  [New LWP 844790]
  [New LWP 844791]
  [New LWP 844792]
  [New LWP 844793]
  [New LWP 844794]
  [New LWP 844795]
  [New LWP 844796]
  [New LWP 844797]
  [New LWP 844798]
  [New LWP 844799]
  [New LWP 844800]
  [New LWP 844801]
  [New LWP 844802]
  [New LWP 844803]
  [New LWP 844804]
  [New LWP 844805]
  [New LWP 844806]
  [New LWP 844807]
  [New LWP 844808]
  [New LWP 844809]
  [New LWP 844810]
  [New LWP 844811]
  [New LWP 844812]
  [New LWP 844813]
  [New LWP 844814]

  Thread 2 "pahole" received signal SIGSEGV, Segmentation fault.
  [Switching to LWP 844789]
  0x00007ffff7dfa321 in ?? () from /lib64/libc.so.6
  (gdb) bt
  #0  0x00007ffff7dfa321 in ?? () from /lib64/libc.so.6
  #1  0x00007ffff7dfa4bb in ?? () from /lib64/libc.so.6
  #2  0x00007ffff7f5eaa6 in __libdw_getsrclines (dbg=0x4a7f90, debug_line_offset=10383710, comp_dir=0x7ffff3c29f01 "/var/home/acme/git/build/v5.13.0-rc6+", address_size=address_size@entry=8, linesp=linesp@entry=0x7fffcfe04ba0, filesp=filesp@entry=0x7fffcfe04ba8)
      at dwarf_getsrclines.c:1129
  #3  0x00007ffff7f5ed14 in dwarf_getsrclines (cudie=cudie@entry=0x7fffd210caf0, lines=lines@entry=0x7fffd210cac0, nlines=nlines@entry=0x7fffd210cac8) at dwarf_getsrclines.c:1213
  #4  0x00007ffff7f64883 in dwarf_decl_file (die=<optimized out>) at dwarf_decl_file.c:66
  #5  0x0000000000425f24 in tag__init (tag=0x7fff0421b710, cu=0x7fffcc001e40, die=0x7fffd210cd30) at /var/home/acme/git/pahole/dwarf_loader.c:476
  #6  0x00000000004262ec in namespace__init (namespace=0x7fff0421b710, die=0x7fffd210cd30, cu=0x7fffcc001e40, conf=0x475600 <conf_load>) at /var/home/acme/git/pahole/dwarf_loader.c:576
  #7  0x00000000004263ac in type__init (type=0x7fff0421b710, die=0x7fffd210cd30, cu=0x7fffcc001e40, conf=0x475600 <conf_load>) at /var/home/acme/git/pahole/dwarf_loader.c:595
  #8  0x00000000004264d1 in type__new (die=0x7fffd210cd30, cu=0x7fffcc001e40, conf=0x475600 <conf_load>) at /var/home/acme/git/pahole/dwarf_loader.c:614
  #9  0x0000000000427ba6 in die__create_new_typedef (die=0x7fffd210cd30, cu=0x7fffcc001e40, conf=0x475600 <conf_load>) at /var/home/acme/git/pahole/dwarf_loader.c:1212
  #10 0x0000000000428df5 in __die__process_tag (die=0x7fffd210cd30, cu=0x7fffcc001e40, top_level=1, fn=0x45cee0 <__FUNCTION__.10> "die__process_unit", conf=0x475600 <conf_load>) at /var/home/acme/git/pahole/dwarf_loader.c:1823
  #11 0x0000000000428ea1 in die__process_unit (die=0x7fffd210cd30, cu=0x7fffcc001e40, conf=0x475600 <conf_load>) at /var/home/acme/git/pahole/dwarf_loader.c:1848
  #12 0x0000000000429e45 in die__process (die=0x7fffd210ce20, cu=0x7fffcc001e40, conf=0x475600 <conf_load>) at /var/home/acme/git/pahole/dwarf_loader.c:2311
  #13 0x0000000000429ecb in die__process_and_recode (die=0x7fffd210ce20, cu=0x7fffcc001e40, conf=0x475600 <conf_load>) at /var/home/acme/git/pahole/dwarf_loader.c:2326
  #14 0x000000000042a9d6 in dwarf_cus__create_and_process_cu (dcus=0x7fffffffddc0, cu_die=0x7fffd210ce20, pointer_size=8 '\b') at /var/home/acme/git/pahole/dwarf_loader.c:2644
  #15 0x000000000042ab28 in dwarf_cus__process_cu_thread (arg=0x7fffffffddc0) at /var/home/acme/git/pahole/dwarf_loader.c:2687
  #16 0x00007ffff7ed6299 in start_thread () from /lib64/libpthread.so.0
  #17 0x00007ffff7dfe353 in ?? () from /lib64/libc.so.6
  (gdb)
  (gdb) fr 2
  1085
  (gdb) list files_lines_compare
  1086    static int
  1087    files_lines_compare (const void *p1, const void *p2)
  1088    {
  1089	  const struct files_lines_s *t1 = p1;
  1090	  const struct files_lines_s *t2 = p2;
  1091
  1092	  if (t1->debug_line_offset < t2->debug_line_offset)
  (gdb)
  1093        return -1;
  1094	  if (t1->debug_line_offset > t2->debug_line_offset)
  1095        return 1;
  1096
  1097	  return 0;
  1098    }
  1099
  1100    int
  1101    internal_function
  1102    __libdw_getsrclines (Dwarf *dbg, Dwarf_Off debug_line_offset,
  (gdb) list __libdw_getsrclines
  1100    int
  1101    internal_function
  1102    __libdw_getsrclines (Dwarf *dbg, Dwarf_Off debug_line_offset,
  1103                         const char *comp_dir, unsigned address_size,
  1104                         Dwarf_Lines **linesp, Dwarf_Files **filesp)
  1105    {
  1106	  struct files_lines_s fake = { .debug_line_offset = debug_line_offset };
  1107	  struct files_lines_s **found = tfind (&fake, &dbg->files_lines,
  1108                                            files_lines_compare);
  1109	  if (found == NULL)
  (gdb)
  1110        {
  1111          Elf_Data *data = __libdw_checked_get_data (dbg, IDX_debug_line);
  1112          if (data == NULL
  1113              || __libdw_offset_in_section (dbg, IDX_debug_line,
  1114                                            debug_line_offset, 1) != 0)
  1115            return -1;
  1116
  1117          const unsigned char *linep = data->d_buf + debug_line_offset;
  1118          const unsigned char *lineendp = data->d_buf + data->d_size;
  1119
  (gdb)
  1120          struct files_lines_s *node = libdw_alloc (dbg, struct files_lines_s,
  1121                                                    sizeof *node, 1);
  1122
  1123          if (read_srclines (dbg, linep, lineendp, comp_dir, address_size,
  1124                             &node->lines, &node->files) != 0)
  1125            return -1;
  1126
  1127          node->debug_line_offset = debug_line_offset;
  1128
  1129          found = tsearch (node, &dbg->files_lines, files_lines_compare);
  (gdb)

Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
acmel added a commit that referenced this issue Jul 28, 2021
…() calls

As this ends up racing on a tsearch() call, probably for some libdw
cache that gets updated/lookedup in concurrent pahole threads (-j N).

This cures the following, a patch for libdw will be cooked up and sent.

  (gdb) run -j -I -F dwarf vmlinux > /dev/null
  Starting program: /var/home/acme/git/pahole/build/pahole -j -I -F dwarf vmlinux > /dev/null
  warning: Expected absolute pathname for libpthread in the inferior, but got .gnu_debugdata for /lib64/libpthread.so.0.
  warning: File "/usr/lib64/libthread_db-1.0.so" auto-loading has been declined by your `auto-load safe-path' set to "$debugdir:$datadir/auto-load".
  warning: Unable to find libthread_db matching inferior's thread library, thread debugging will not be available.
  [New LWP 844789]
  [New LWP 844790]
  [New LWP 844791]
  [New LWP 844792]
  [New LWP 844793]
  [New LWP 844794]
  [New LWP 844795]
  [New LWP 844796]
  [New LWP 844797]
  [New LWP 844798]
  [New LWP 844799]
  [New LWP 844800]
  [New LWP 844801]
  [New LWP 844802]
  [New LWP 844803]
  [New LWP 844804]
  [New LWP 844805]
  [New LWP 844806]
  [New LWP 844807]
  [New LWP 844808]
  [New LWP 844809]
  [New LWP 844810]
  [New LWP 844811]
  [New LWP 844812]
  [New LWP 844813]
  [New LWP 844814]

  Thread 2 "pahole" received signal SIGSEGV, Segmentation fault.
  [Switching to LWP 844789]
  0x00007ffff7dfa321 in ?? () from /lib64/libc.so.6
  (gdb) bt
  #0  0x00007ffff7dfa321 in ?? () from /lib64/libc.so.6
  #1  0x00007ffff7dfa4bb in ?? () from /lib64/libc.so.6
  #2  0x00007ffff7f5eaa6 in __libdw_getsrclines (dbg=0x4a7f90, debug_line_offset=10383710, comp_dir=0x7ffff3c29f01 "/var/home/acme/git/build/v5.13.0-rc6+", address_size=address_size@entry=8, linesp=linesp@entry=0x7fffcfe04ba0, filesp=filesp@entry=0x7fffcfe04ba8)
      at dwarf_getsrclines.c:1129
  #3  0x00007ffff7f5ed14 in dwarf_getsrclines (cudie=cudie@entry=0x7fffd210caf0, lines=lines@entry=0x7fffd210cac0, nlines=nlines@entry=0x7fffd210cac8) at dwarf_getsrclines.c:1213
  #4  0x00007ffff7f64883 in dwarf_decl_file (die=<optimized out>) at dwarf_decl_file.c:66
  #5  0x0000000000425f24 in tag__init (tag=0x7fff0421b710, cu=0x7fffcc001e40, die=0x7fffd210cd30) at /var/home/acme/git/pahole/dwarf_loader.c:476
  #6  0x00000000004262ec in namespace__init (namespace=0x7fff0421b710, die=0x7fffd210cd30, cu=0x7fffcc001e40, conf=0x475600 <conf_load>) at /var/home/acme/git/pahole/dwarf_loader.c:576
  #7  0x00000000004263ac in type__init (type=0x7fff0421b710, die=0x7fffd210cd30, cu=0x7fffcc001e40, conf=0x475600 <conf_load>) at /var/home/acme/git/pahole/dwarf_loader.c:595
  #8  0x00000000004264d1 in type__new (die=0x7fffd210cd30, cu=0x7fffcc001e40, conf=0x475600 <conf_load>) at /var/home/acme/git/pahole/dwarf_loader.c:614
  #9  0x0000000000427ba6 in die__create_new_typedef (die=0x7fffd210cd30, cu=0x7fffcc001e40, conf=0x475600 <conf_load>) at /var/home/acme/git/pahole/dwarf_loader.c:1212
  #10 0x0000000000428df5 in __die__process_tag (die=0x7fffd210cd30, cu=0x7fffcc001e40, top_level=1, fn=0x45cee0 <__FUNCTION__.10> "die__process_unit", conf=0x475600 <conf_load>) at /var/home/acme/git/pahole/dwarf_loader.c:1823
  #11 0x0000000000428ea1 in die__process_unit (die=0x7fffd210cd30, cu=0x7fffcc001e40, conf=0x475600 <conf_load>) at /var/home/acme/git/pahole/dwarf_loader.c:1848
  #12 0x0000000000429e45 in die__process (die=0x7fffd210ce20, cu=0x7fffcc001e40, conf=0x475600 <conf_load>) at /var/home/acme/git/pahole/dwarf_loader.c:2311
  #13 0x0000000000429ecb in die__process_and_recode (die=0x7fffd210ce20, cu=0x7fffcc001e40, conf=0x475600 <conf_load>) at /var/home/acme/git/pahole/dwarf_loader.c:2326
  #14 0x000000000042a9d6 in dwarf_cus__create_and_process_cu (dcus=0x7fffffffddc0, cu_die=0x7fffd210ce20, pointer_size=8 '\b') at /var/home/acme/git/pahole/dwarf_loader.c:2644
  #15 0x000000000042ab28 in dwarf_cus__process_cu_thread (arg=0x7fffffffddc0) at /var/home/acme/git/pahole/dwarf_loader.c:2687
  #16 0x00007ffff7ed6299 in start_thread () from /lib64/libpthread.so.0
  #17 0x00007ffff7dfe353 in ?? () from /lib64/libc.so.6
  (gdb)
  (gdb) fr 2
  1085
  (gdb) list files_lines_compare
  1086    static int
  1087    files_lines_compare (const void *p1, const void *p2)
  1088    {
  1089	  const struct files_lines_s *t1 = p1;
  1090	  const struct files_lines_s *t2 = p2;
  1091
  1092	  if (t1->debug_line_offset < t2->debug_line_offset)
  (gdb)
  1093        return -1;
  1094	  if (t1->debug_line_offset > t2->debug_line_offset)
  1095        return 1;
  1096
  1097	  return 0;
  1098    }
  1099
  1100    int
  1101    internal_function
  1102    __libdw_getsrclines (Dwarf *dbg, Dwarf_Off debug_line_offset,
  (gdb) list __libdw_getsrclines
  1100    int
  1101    internal_function
  1102    __libdw_getsrclines (Dwarf *dbg, Dwarf_Off debug_line_offset,
  1103                         const char *comp_dir, unsigned address_size,
  1104                         Dwarf_Lines **linesp, Dwarf_Files **filesp)
  1105    {
  1106	  struct files_lines_s fake = { .debug_line_offset = debug_line_offset };
  1107	  struct files_lines_s **found = tfind (&fake, &dbg->files_lines,
  1108                                            files_lines_compare);
  1109	  if (found == NULL)
  (gdb)
  1110        {
  1111          Elf_Data *data = __libdw_checked_get_data (dbg, IDX_debug_line);
  1112          if (data == NULL
  1113              || __libdw_offset_in_section (dbg, IDX_debug_line,
  1114                                            debug_line_offset, 1) != 0)
  1115            return -1;
  1116
  1117          const unsigned char *linep = data->d_buf + debug_line_offset;
  1118          const unsigned char *lineendp = data->d_buf + data->d_size;
  1119
  (gdb)
  1120          struct files_lines_s *node = libdw_alloc (dbg, struct files_lines_s,
  1121                                                    sizeof *node, 1);
  1122
  1123          if (read_srclines (dbg, linep, lineendp, comp_dir, address_size,
  1124                             &node->lines, &node->files) != 0)
  1125            return -1;
  1126
  1127          node->debug_line_offset = debug_line_offset;
  1128
  1129          found = tsearch (node, &dbg->files_lines, files_lines_compare);
  (gdb)

Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
acmel added a commit that referenced this issue Aug 6, 2021
…() calls

As this ends up racing on a tsearch() call, probably for some libdw
cache that gets updated/lookedup in concurrent pahole threads (-j N).

This cures the following, a patch for libdw will be cooked up and sent.

  (gdb) run -j -I -F dwarf vmlinux > /dev/null
  Starting program: /var/home/acme/git/pahole/build/pahole -j -I -F dwarf vmlinux > /dev/null
  warning: Expected absolute pathname for libpthread in the inferior, but got .gnu_debugdata for /lib64/libpthread.so.0.
  warning: File "/usr/lib64/libthread_db-1.0.so" auto-loading has been declined by your `auto-load safe-path' set to "$debugdir:$datadir/auto-load".
  warning: Unable to find libthread_db matching inferior's thread library, thread debugging will not be available.
  [New LWP 844789]
  [New LWP 844790]
  [New LWP 844791]
  [New LWP 844792]
  [New LWP 844793]
  [New LWP 844794]
  [New LWP 844795]
  [New LWP 844796]
  [New LWP 844797]
  [New LWP 844798]
  [New LWP 844799]
  [New LWP 844800]
  [New LWP 844801]
  [New LWP 844802]
  [New LWP 844803]
  [New LWP 844804]
  [New LWP 844805]
  [New LWP 844806]
  [New LWP 844807]
  [New LWP 844808]
  [New LWP 844809]
  [New LWP 844810]
  [New LWP 844811]
  [New LWP 844812]
  [New LWP 844813]
  [New LWP 844814]

  Thread 2 "pahole" received signal SIGSEGV, Segmentation fault.
  [Switching to LWP 844789]
  0x00007ffff7dfa321 in ?? () from /lib64/libc.so.6
  (gdb) bt
  #0  0x00007ffff7dfa321 in ?? () from /lib64/libc.so.6
  #1  0x00007ffff7dfa4bb in ?? () from /lib64/libc.so.6
  #2  0x00007ffff7f5eaa6 in __libdw_getsrclines (dbg=0x4a7f90, debug_line_offset=10383710, comp_dir=0x7ffff3c29f01 "/var/home/acme/git/build/v5.13.0-rc6+", address_size=address_size@entry=8, linesp=linesp@entry=0x7fffcfe04ba0, filesp=filesp@entry=0x7fffcfe04ba8)
      at dwarf_getsrclines.c:1129
  #3  0x00007ffff7f5ed14 in dwarf_getsrclines (cudie=cudie@entry=0x7fffd210caf0, lines=lines@entry=0x7fffd210cac0, nlines=nlines@entry=0x7fffd210cac8) at dwarf_getsrclines.c:1213
  #4  0x00007ffff7f64883 in dwarf_decl_file (die=<optimized out>) at dwarf_decl_file.c:66
  #5  0x0000000000425f24 in tag__init (tag=0x7fff0421b710, cu=0x7fffcc001e40, die=0x7fffd210cd30) at /var/home/acme/git/pahole/dwarf_loader.c:476
  #6  0x00000000004262ec in namespace__init (namespace=0x7fff0421b710, die=0x7fffd210cd30, cu=0x7fffcc001e40, conf=0x475600 <conf_load>) at /var/home/acme/git/pahole/dwarf_loader.c:576
  #7  0x00000000004263ac in type__init (type=0x7fff0421b710, die=0x7fffd210cd30, cu=0x7fffcc001e40, conf=0x475600 <conf_load>) at /var/home/acme/git/pahole/dwarf_loader.c:595
  #8  0x00000000004264d1 in type__new (die=0x7fffd210cd30, cu=0x7fffcc001e40, conf=0x475600 <conf_load>) at /var/home/acme/git/pahole/dwarf_loader.c:614
  #9  0x0000000000427ba6 in die__create_new_typedef (die=0x7fffd210cd30, cu=0x7fffcc001e40, conf=0x475600 <conf_load>) at /var/home/acme/git/pahole/dwarf_loader.c:1212
  #10 0x0000000000428df5 in __die__process_tag (die=0x7fffd210cd30, cu=0x7fffcc001e40, top_level=1, fn=0x45cee0 <__FUNCTION__.10> "die__process_unit", conf=0x475600 <conf_load>) at /var/home/acme/git/pahole/dwarf_loader.c:1823
  #11 0x0000000000428ea1 in die__process_unit (die=0x7fffd210cd30, cu=0x7fffcc001e40, conf=0x475600 <conf_load>) at /var/home/acme/git/pahole/dwarf_loader.c:1848
  #12 0x0000000000429e45 in die__process (die=0x7fffd210ce20, cu=0x7fffcc001e40, conf=0x475600 <conf_load>) at /var/home/acme/git/pahole/dwarf_loader.c:2311
  #13 0x0000000000429ecb in die__process_and_recode (die=0x7fffd210ce20, cu=0x7fffcc001e40, conf=0x475600 <conf_load>) at /var/home/acme/git/pahole/dwarf_loader.c:2326
  #14 0x000000000042a9d6 in dwarf_cus__create_and_process_cu (dcus=0x7fffffffddc0, cu_die=0x7fffd210ce20, pointer_size=8 '\b') at /var/home/acme/git/pahole/dwarf_loader.c:2644
  #15 0x000000000042ab28 in dwarf_cus__process_cu_thread (arg=0x7fffffffddc0) at /var/home/acme/git/pahole/dwarf_loader.c:2687
  #16 0x00007ffff7ed6299 in start_thread () from /lib64/libpthread.so.0
  #17 0x00007ffff7dfe353 in ?? () from /lib64/libc.so.6
  (gdb)
  (gdb) fr 2
  1085
  (gdb) list files_lines_compare
  1086    static int
  1087    files_lines_compare (const void *p1, const void *p2)
  1088    {
  1089	  const struct files_lines_s *t1 = p1;
  1090	  const struct files_lines_s *t2 = p2;
  1091
  1092	  if (t1->debug_line_offset < t2->debug_line_offset)
  (gdb)
  1093        return -1;
  1094	  if (t1->debug_line_offset > t2->debug_line_offset)
  1095        return 1;
  1096
  1097	  return 0;
  1098    }
  1099
  1100    int
  1101    internal_function
  1102    __libdw_getsrclines (Dwarf *dbg, Dwarf_Off debug_line_offset,
  (gdb) list __libdw_getsrclines
  1100    int
  1101    internal_function
  1102    __libdw_getsrclines (Dwarf *dbg, Dwarf_Off debug_line_offset,
  1103                         const char *comp_dir, unsigned address_size,
  1104                         Dwarf_Lines **linesp, Dwarf_Files **filesp)
  1105    {
  1106	  struct files_lines_s fake = { .debug_line_offset = debug_line_offset };
  1107	  struct files_lines_s **found = tfind (&fake, &dbg->files_lines,
  1108                                            files_lines_compare);
  1109	  if (found == NULL)
  (gdb)
  1110        {
  1111          Elf_Data *data = __libdw_checked_get_data (dbg, IDX_debug_line);
  1112          if (data == NULL
  1113              || __libdw_offset_in_section (dbg, IDX_debug_line,
  1114                                            debug_line_offset, 1) != 0)
  1115            return -1;
  1116
  1117          const unsigned char *linep = data->d_buf + debug_line_offset;
  1118          const unsigned char *lineendp = data->d_buf + data->d_size;
  1119
  (gdb)
  1120          struct files_lines_s *node = libdw_alloc (dbg, struct files_lines_s,
  1121                                                    sizeof *node, 1);
  1122
  1123          if (read_srclines (dbg, linep, lineendp, comp_dir, address_size,
  1124                             &node->lines, &node->files) != 0)
  1125            return -1;
  1126
  1127          node->debug_line_offset = debug_line_offset;
  1128
  1129          found = tsearch (node, &dbg->files_lines, files_lines_compare);
  (gdb)

Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
acmel added a commit that referenced this issue Aug 12, 2021
…() calls

As this ends up racing on a tsearch() call, probably for some libdw
cache that gets updated/lookedup in concurrent pahole threads (-j N).

This cures the following, a patch for libdw will be cooked up and sent.

  (gdb) run -j -I -F dwarf vmlinux > /dev/null
  Starting program: /var/home/acme/git/pahole/build/pahole -j -I -F dwarf vmlinux > /dev/null
  warning: Expected absolute pathname for libpthread in the inferior, but got .gnu_debugdata for /lib64/libpthread.so.0.
  warning: File "/usr/lib64/libthread_db-1.0.so" auto-loading has been declined by your `auto-load safe-path' set to "$debugdir:$datadir/auto-load".
  warning: Unable to find libthread_db matching inferior's thread library, thread debugging will not be available.
  [New LWP 844789]
  [New LWP 844790]
  [New LWP 844791]
  [New LWP 844792]
  [New LWP 844793]
  [New LWP 844794]
  [New LWP 844795]
  [New LWP 844796]
  [New LWP 844797]
  [New LWP 844798]
  [New LWP 844799]
  [New LWP 844800]
  [New LWP 844801]
  [New LWP 844802]
  [New LWP 844803]
  [New LWP 844804]
  [New LWP 844805]
  [New LWP 844806]
  [New LWP 844807]
  [New LWP 844808]
  [New LWP 844809]
  [New LWP 844810]
  [New LWP 844811]
  [New LWP 844812]
  [New LWP 844813]
  [New LWP 844814]

  Thread 2 "pahole" received signal SIGSEGV, Segmentation fault.
  [Switching to LWP 844789]
  0x00007ffff7dfa321 in ?? () from /lib64/libc.so.6
  (gdb) bt
  #0  0x00007ffff7dfa321 in ?? () from /lib64/libc.so.6
  #1  0x00007ffff7dfa4bb in ?? () from /lib64/libc.so.6
  #2  0x00007ffff7f5eaa6 in __libdw_getsrclines (dbg=0x4a7f90, debug_line_offset=10383710, comp_dir=0x7ffff3c29f01 "/var/home/acme/git/build/v5.13.0-rc6+", address_size=address_size@entry=8, linesp=linesp@entry=0x7fffcfe04ba0, filesp=filesp@entry=0x7fffcfe04ba8)
      at dwarf_getsrclines.c:1129
  #3  0x00007ffff7f5ed14 in dwarf_getsrclines (cudie=cudie@entry=0x7fffd210caf0, lines=lines@entry=0x7fffd210cac0, nlines=nlines@entry=0x7fffd210cac8) at dwarf_getsrclines.c:1213
  #4  0x00007ffff7f64883 in dwarf_decl_file (die=<optimized out>) at dwarf_decl_file.c:66
  #5  0x0000000000425f24 in tag__init (tag=0x7fff0421b710, cu=0x7fffcc001e40, die=0x7fffd210cd30) at /var/home/acme/git/pahole/dwarf_loader.c:476
  #6  0x00000000004262ec in namespace__init (namespace=0x7fff0421b710, die=0x7fffd210cd30, cu=0x7fffcc001e40, conf=0x475600 <conf_load>) at /var/home/acme/git/pahole/dwarf_loader.c:576
  #7  0x00000000004263ac in type__init (type=0x7fff0421b710, die=0x7fffd210cd30, cu=0x7fffcc001e40, conf=0x475600 <conf_load>) at /var/home/acme/git/pahole/dwarf_loader.c:595
  #8  0x00000000004264d1 in type__new (die=0x7fffd210cd30, cu=0x7fffcc001e40, conf=0x475600 <conf_load>) at /var/home/acme/git/pahole/dwarf_loader.c:614
  #9  0x0000000000427ba6 in die__create_new_typedef (die=0x7fffd210cd30, cu=0x7fffcc001e40, conf=0x475600 <conf_load>) at /var/home/acme/git/pahole/dwarf_loader.c:1212
  #10 0x0000000000428df5 in __die__process_tag (die=0x7fffd210cd30, cu=0x7fffcc001e40, top_level=1, fn=0x45cee0 <__FUNCTION__.10> "die__process_unit", conf=0x475600 <conf_load>) at /var/home/acme/git/pahole/dwarf_loader.c:1823
  #11 0x0000000000428ea1 in die__process_unit (die=0x7fffd210cd30, cu=0x7fffcc001e40, conf=0x475600 <conf_load>) at /var/home/acme/git/pahole/dwarf_loader.c:1848
  #12 0x0000000000429e45 in die__process (die=0x7fffd210ce20, cu=0x7fffcc001e40, conf=0x475600 <conf_load>) at /var/home/acme/git/pahole/dwarf_loader.c:2311
  #13 0x0000000000429ecb in die__process_and_recode (die=0x7fffd210ce20, cu=0x7fffcc001e40, conf=0x475600 <conf_load>) at /var/home/acme/git/pahole/dwarf_loader.c:2326
  #14 0x000000000042a9d6 in dwarf_cus__create_and_process_cu (dcus=0x7fffffffddc0, cu_die=0x7fffd210ce20, pointer_size=8 '\b') at /var/home/acme/git/pahole/dwarf_loader.c:2644
  #15 0x000000000042ab28 in dwarf_cus__process_cu_thread (arg=0x7fffffffddc0) at /var/home/acme/git/pahole/dwarf_loader.c:2687
  #16 0x00007ffff7ed6299 in start_thread () from /lib64/libpthread.so.0
  #17 0x00007ffff7dfe353 in ?? () from /lib64/libc.so.6
  (gdb)
  (gdb) fr 2
  1085
  (gdb) list files_lines_compare
  1086    static int
  1087    files_lines_compare (const void *p1, const void *p2)
  1088    {
  1089	  const struct files_lines_s *t1 = p1;
  1090	  const struct files_lines_s *t2 = p2;
  1091
  1092	  if (t1->debug_line_offset < t2->debug_line_offset)
  (gdb)
  1093        return -1;
  1094	  if (t1->debug_line_offset > t2->debug_line_offset)
  1095        return 1;
  1096
  1097	  return 0;
  1098    }
  1099
  1100    int
  1101    internal_function
  1102    __libdw_getsrclines (Dwarf *dbg, Dwarf_Off debug_line_offset,
  (gdb) list __libdw_getsrclines
  1100    int
  1101    internal_function
  1102    __libdw_getsrclines (Dwarf *dbg, Dwarf_Off debug_line_offset,
  1103                         const char *comp_dir, unsigned address_size,
  1104                         Dwarf_Lines **linesp, Dwarf_Files **filesp)
  1105    {
  1106	  struct files_lines_s fake = { .debug_line_offset = debug_line_offset };
  1107	  struct files_lines_s **found = tfind (&fake, &dbg->files_lines,
  1108                                            files_lines_compare);
  1109	  if (found == NULL)
  (gdb)
  1110        {
  1111          Elf_Data *data = __libdw_checked_get_data (dbg, IDX_debug_line);
  1112          if (data == NULL
  1113              || __libdw_offset_in_section (dbg, IDX_debug_line,
  1114                                            debug_line_offset, 1) != 0)
  1115            return -1;
  1116
  1117          const unsigned char *linep = data->d_buf + debug_line_offset;
  1118          const unsigned char *lineendp = data->d_buf + data->d_size;
  1119
  (gdb)
  1120          struct files_lines_s *node = libdw_alloc (dbg, struct files_lines_s,
  1121                                                    sizeof *node, 1);
  1122
  1123          if (read_srclines (dbg, linep, lineendp, comp_dir, address_size,
  1124                             &node->lines, &node->files) != 0)
  1125            return -1;
  1126
  1127          node->debug_line_offset = debug_line_offset;
  1128
  1129          found = tsearch (node, &dbg->files_lines, files_lines_compare);
  (gdb)

Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
acmel added a commit that referenced this issue Jan 28, 2022
…ne_size field

tldr;

  gdb pfunct
  (gdb) run --compile tcp.o
  Program received signal SIGFPE, Arithmetic exception.
  0x00007ffff7f18551 in class__fprintf_cacheline_boundary (conf=0x7fffffffda10, offset=0, fp=0x7ffff7e17520 <_IO_2_1_stdout_>) at /var/home/acme/git/pahole/dwarves_fprintf.c:1319
  1319		uint32_t cacheline = offset / conf->cacheline_size;
  (gdb) bt
  #0  0x00007ffff7f18551 in class__fprintf_cacheline_boundary (conf=0x7fffffffda10, offset=0, fp=0x7ffff7e17520 <_IO_2_1_stdout_>) at /var/home/acme/git/pahole/dwarves_fprintf.c:1319
  #1  0x00007ffff7f16af2 in class_member__fprintf (member=0x45de10, union_member=false, type=0x45dfb0, cu=0x435a40, conf=0x7fffffffda10, fp=0x7ffff7e17520 <_IO_2_1_stdout_>) at /var/home/acme/git/pahole/dwarves_fprintf.c:869
  #2  0x00007ffff7f1717b in struct_member__fprintf (member=0x45de10, type=0x45dfb0, cu=0x435a40, conf=0x7fffffffda10, fp=0x7ffff7e17520 <_IO_2_1_stdout_>) at /var/home/acme/git/pahole/dwarves_fprintf.c:983
  #3  0x00007ffff7f1945c in __class__fprintf (class=0x45dcc0, cu=0x435a40, conf=0x7fffffffdbb0, fp=0x7ffff7e17520 <_IO_2_1_stdout_>) at /var/home/acme/git/pahole/dwarves_fprintf.c:1583
  #4  0x00007ffff7f1a6bd in tag__fprintf (tag=0x45dcc0, cu=0x435a40, conf=0x7fffffffdc70, fp=0x7ffff7e17520 <_IO_2_1_stdout_>) at /var/home/acme/git/pahole/dwarves_fprintf.c:1906
  #5  0x00007ffff7fbf022 in type__emit (tag=0x45dcc0, cu=0x435a40, prefix=0x0, suffix=0x0, fp=0x7ffff7e17520 <_IO_2_1_stdout_>) at /var/home/acme/git/pahole/dwarves_emit.c:333
  #6  0x00007ffff7fbed3d in tag__emit_definitions (tag=0x6b21e0, cu=0x435a40, emissions=0x408300 <emissions>, fp=0x7ffff7e17520 <_IO_2_1_stdout_>) at /var/home/acme/git/pahole/dwarves_emit.c:265
  #7  0x00007ffff7fbef45 in type__emit_definitions (tag=0x6b20c0, cu=0x435a40, emissions=0x408300 <emissions>, fp=0x7ffff7e17520 <_IO_2_1_stdout_>) at /var/home/acme/git/pahole/dwarves_emit.c:315
  #8  0x00007ffff7fbed15 in tag__emit_definitions (tag=0x6b3b40, cu=0x435a40, emissions=0x408300 <emissions>, fp=0x7ffff7e17520 <_IO_2_1_stdout_>) at /var/home/acme/git/pahole/dwarves_emit.c:264
  #9  0x00007ffff7fbef45 in type__emit_definitions (tag=0x6b31d0, cu=0x435a40, emissions=0x408300 <emissions>, fp=0x7ffff7e17520 <_IO_2_1_stdout_>) at /var/home/acme/git/pahole/dwarves_emit.c:315
  #10 0x00007ffff7fbed15 in tag__emit_definitions (tag=0x4cb920, cu=0x435a40, emissions=0x408300 <emissions>, fp=0x7ffff7e17520 <_IO_2_1_stdout_>) at /var/home/acme/git/pahole/dwarves_emit.c:264
  #11 0x00007ffff7fbef45 in type__emit_definitions (tag=0x4cb7d0, cu=0x435a40, emissions=0x408300 <emissions>, fp=0x7ffff7e17520 <_IO_2_1_stdout_>) at /var/home/acme/git/pahole/dwarves_emit.c:315
  #12 0x0000000000403592 in function__emit_type_definitions (func=0x738ad0, cu=0x435a40, fp=0x7ffff7e17520 <_IO_2_1_stdout_>) at /var/home/acme/git/pahole/pfunct.c:353
  #13 0x0000000000403670 in function__show (func=0x738ad0, cu=0x435a40) at /var/home/acme/git/pahole/pfunct.c:371
  #14 0x00000000004038e9 in cu_function_iterator (cu=0x435a40, cookie=0x0) at /var/home/acme/git/pahole/pfunct.c:404
  #15 0x00007ffff7f1296b in cus__for_each_cu (cus=0x4369e0, iterator=0x403869 <cu_function_iterator>, cookie=0x0, filter=0x0) at /var/home/acme/git/pahole/dwarves.c:1919
  #16 0x000000000040432a in main (argc=3, argv=0x7fffffffe1f8) at /var/home/acme/git/pahole/pfunct.c:776
  (gdb) p conf->cacheline_size
  $2 = 0

We need to pass a conf_fprintf pointer to the chain starting with
function__emit_type_definitions(), i.e. dwarves_emit.c needs to receive
the printing configuration instead of, right at type__emit() synthesize
a conf_fprintf without initializing conf_fprintf->cacheline_size which
ends up in a division by zero.

But to fix this quicker just add a helper that checks if it is zero and
uses the conf_fprintf__defaults.cacheline_size field that is being
initialized by all tools via:

  dwarves__resolve_cacheline_size(&conf_load, 0);

Fixes: 772725a ("dwarves_fprintf: Move cacheline_size into struct conf_fprintf")
Cc: Douglas Raillard <[email protected]>
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
acmel added a commit that referenced this issue Jun 18, 2024
In cu__new() zalloc() is used defensively, and that helped catch this
problem where we assume that a cu us in the cus list of cu instances,
but that is not the case when we use cus__merge_and_process_cu(), for
instance when loading files created by clang with LTO, as reported by
Peter Jung and narrowed down by Nathan Chancellor.

If we use INIT_LIST_HEAD() in cu__new() to initialize cu->node, which is
what we do with other lists and nodes there, then the unconditional
removal using list_del_init() will be a no-op and removing something not
on the cus list of cu instances will not cause problems, just keep an
unconsistent cus->nr_entries field.

So lets just have this fix in first, keeping Nathan's Tested-by and then
do the a bit more involved fix of either adding that cu to the cus list
or checking at removal time if it is there.

  Program received signal SIGSEGV, Segmentation fault.
  0x00007ffff7f1e13e in __list_del (prev=0x0, next=0x0) at /home/acme/git/pahole/list.h:106
  106		next->prev = prev;
  (gdb) bt
  #0  0x00007ffff7f1e13e in __list_del (prev=0x0, next=0x0) at /home/acme/git/pahole/list.h:106
  #1  0x00007ffff7f1e176 in list_del_init (entry=0x417980) at /home/acme/git/pahole/list.h:165
  #2  0x00007ffff7f1f8f9 in __cus__remove (cus=0x4142a0, cu=0x417980) at /home/acme/git/pahole/dwarves.c:527
  #3  0x00007ffff7f1f92b in cus__remove (cus=0x4142a0, cu=0x417980) at /home/acme/git/pahole/dwarves.c:533
  #4  0x00007ffff7f3d01c in cus__finalize (cus=0x4142a0, cu=0x417980, conf=0x4133c0 <conf_load>, thr_data=0x0)
      at /home/acme/git/pahole/dwarf_loader.c:3040
  #5  0x00007ffff7f3e05c in cus__merge_and_process_cu (cus=0x4142a0, conf=0x4133c0 <conf_load>, mod=0x415cf0, dw=0x416110, elf=0x414380,
      filename=0x7fffffffe3f7 "cast_common.ko", build_id=0x416680 "\265D\371U\213\373u|\037\250\242\032\271\365⒜]y\023", build_id_len=20,
      type_dcu=0x0) at /home/acme/git/pahole/dwarf_loader.c:3482
  #6  0x00007ffff7f3e218 in cus__load_module (cus=0x4142a0, conf=0x4133c0 <conf_load>, mod=0x415cf0, dw=0x416110, elf=0x414380,
      filename=0x7fffffffe3f7 "cast_common.ko") at /home/acme/git/pahole/dwarf_loader.c:3521
  #7  0x00007ffff7f3e396 in cus__process_dwflmod (dwflmod=0x415cf0, userdata=0x415d00, name=0x415ea0 "cast_common.ko", base=65536,
      arg=0x7fffffffde40) at /home/acme/git/pahole/dwarf_loader.c:3581
  #8  0x00007ffff7eb4609 in dwfl_getmodules (dwfl=0x414300, callback=0x7ffff7f3e2ec <cus__process_dwflmod>, arg=0x7fffffffde40, offset=0)
      at ../libdwfl/dwfl_getmodules.c:86
  #9  0x00007ffff7f3e4c5 in cus__process_file (cus=0x4142a0, conf=0x4133c0 <conf_load>, fd=3, filename=0x7fffffffe3f7 "cast_common.ko")
      at /home/acme/git/pahole/dwarf_loader.c:3647
  #10 0x00007ffff7f3e5cd in dwarf__load_file (cus=0x4142a0, conf=0x4133c0 <conf_load>, filename=0x7fffffffe3f7 "cast_common.ko")
      at /home/acme/git/pahole/dwarf_loader.c:3684
  #11 0x00007ffff7f232df in cus__load_file (cus=0x4142a0, conf=0x4133c0 <conf_load>, filename=0x7fffffffe3f7 "cast_common.ko")
      at /home/acme/git/pahole/dwarves.c:2134
  #12 0x00007ffff7f23e8b in cus__load_files (cus=0x4142a0, conf=0x4133c0 <conf_load>, filenames=0x7fffffffe0f0)
      at /home/acme/git/pahole/dwarves.c:2637
  #13 0x000000000040aec0 in main (argc=2, argv=0x7fffffffe0e8) at /home/acme/git/pahole/pahole.c:3805
  (gdb) fr 1
  #1  0x00007ffff7f1e176 in list_del_init (entry=0x417980) at /home/acme/git/pahole/list.h:165
  165		__list_del(entry->prev, entry->next);
  (gdb) p entry
  $1 = (struct list_head *) 0x417980
  (gdb) p entry->next
  $2 = (struct list_head *) 0x0
  (gdb) p entry->prev
  $3 = (struct list_head *) 0x0

Closes: #53
Closes: https://gitlab.archlinux.org/archlinux/packaging/packages/pahole/-/issues/1
Tested-by: Nathan Chancellor <[email protected]>
Link: https://lore.kernel.org/all/20240617210810.GA1877676@thelio-3990X
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Labels
None yet
Projects
None yet
Development

No branches or pull requests

1 participant