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| author | Fangrui Song <maskray@google.com> | 2022-04-20 10:24:15 -0700 |
|---|---|---|
| committer | Fangrui Song <maskray@google.com> | 2022-04-20 10:24:16 -0700 |
| commit | a8e9b5b8079d18116ca69c9797e77804ecf2ee7e (patch) | |
| tree | 0bdf2e984569e8369740ae861ef839cc1ffeb4cb | |
| parent | 62be9681677e7ce820db721c126909979382d379 (diff) | |
| download | glibc-a8e9b5b8079d18116ca69c9797e77804ecf2ee7e.tar.gz | |
m68k: Handle fewer relocations for RTLD_BOOTSTRAP (#BZ29071)
m68k is a non-PI_STATIC_AND_HIDDEN arch which uses a GOT relocation when
loading the address of a jump table. The GOT load may be reordered
before processing R_68K_RELATIVE relocations, leading to an
unrelocated/incorrect jump table, which will cause a crash.
The foolproof approach is to add an optimization barrier (e.g. calling
an non-inlinable function after relative relocations are resolved). That
is non-trivial given the current code structure, so just use the simple
approach to avoid the jump table: handle only the essential reloctions
for RTLD_BOOTSTRAP code.
This is based on Andreas Schwab's patch and fixed ld.so crash on m68k.
Reviewed-by: Adheemrval Zanella <adhemerval.zanella@linaro.org>
| -rw-r--r-- | sysdeps/m68k/dl-machine.h | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/sysdeps/m68k/dl-machine.h b/sysdeps/m68k/dl-machine.h index c44ab055aa..bb51b4198c 100644 --- a/sysdeps/m68k/dl-machine.h +++ b/sysdeps/m68k/dl-machine.h @@ -234,6 +234,11 @@ elf_machine_rela (struct link_map *map, struct r_scope_elem *scope[], switch (r_type) { + case R_68K_GLOB_DAT: + case R_68K_JMP_SLOT: + *reloc_addr = value; + break; +#ifndef RTLD_BOOTSTRAP case R_68K_COPY: if (sym == NULL) /* This can happen in trace mode if an object could not be @@ -252,10 +257,6 @@ elf_machine_rela (struct link_map *map, struct r_scope_elem *scope[], memcpy (reloc_addr_arg, (void *) value, MIN (sym->st_size, refsym->st_size)); break; - case R_68K_GLOB_DAT: - case R_68K_JMP_SLOT: - *reloc_addr = value; - break; case R_68K_8: *(char *) reloc_addr = value + reloc->r_addend; break; @@ -276,7 +277,6 @@ elf_machine_rela (struct link_map *map, struct r_scope_elem *scope[], case R_68K_PC32: *reloc_addr = value + reloc->r_addend - (Elf32_Addr) reloc_addr; break; -#ifndef RTLD_BOOTSTRAP case R_68K_TLS_DTPMOD32: /* Get the information from the link map returned by the resolv function. */ @@ -294,9 +294,9 @@ elf_machine_rela (struct link_map *map, struct r_scope_elem *scope[], *reloc_addr = TLS_TPREL_VALUE (sym_map, sym, reloc); } break; -#endif /* !RTLD_BOOTSTRAP */ case R_68K_NONE: /* Alright, Wilbur. */ break; +#endif /* !RTLD_BOOTSTRAP */ default: _dl_reloc_bad_type (map, r_type, 0); break; |