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| author | Adhemerval Zanella <adhemerval.zanella@linaro.org> | 2021-10-11 16:01:49 -0300 |
|---|---|---|
| committer | Adhemerval Zanella <adhemerval.zanella@linaro.org> | 2021-10-12 13:25:43 -0300 |
| commit | 4af6982e4c9fc465ffb7a54b794aaaa134241f05 (patch) | |
| tree | 0bd45a2f9ee0aaa1a5c4838132b90681ad47df6d /elf/get-dynamic-info.h | |
| parent | de82cb0da4b8fa5b3d56c457438d2568c67ab1b1 (diff) | |
| download | glibc-4af6982e4c9fc465ffb7a54b794aaaa134241f05.tar.gz glibc-4af6982e4c9fc465ffb7a54b794aaaa134241f05.tar.xz glibc-4af6982e4c9fc465ffb7a54b794aaaa134241f05.zip | |
elf: Fix elf_get_dynamic_info definition
Before to 490e6c62aa31a8a ('elf: Avoid nested functions in the loader
[BZ #27220]'), elf_get_dynamic_info() was defined twice on rtld.c: on
the first dynamic-link.h include and later within _dl_start(). The
former definition did not define DONT_USE_BOOTSTRAP_MAP and it is used
on setup_vdso() (since it is a global definition), while the former does
define DONT_USE_BOOTSTRAP_MAP and it is used on loader self-relocation.
With the commit change, the function is now included and defined once
instead of defined as a nested function. So rtld.c defines without
defining RTLD_BOOTSTRAP and it brokes at least powerpc32.
This patch fixes by moving the get-dynamic-info.h include out of
dynamic-link.h, which then the caller can corirectly set the expected
semantic by defining STATIC_PIE_BOOTSTRAP, RTLD_BOOTSTRAP, and/or
RESOLVE_MAP.
It also required to enable some asserts only for the loader bootstrap
to avoid issues when called from setup_vdso().
As a side note, this is another issues with nested functions: it is
not clear from pre-processed output (-E -dD) how the function will
be build and its semantic (since nested function will be local and
extra C defines may change it).
I checked on x86_64-linux-gnu (w/o --enable-static-pie),
i686-linux-gnu, powerpc64-linux-gnu, powerpc-linux-gnu-power4,
aarch64-linux-gnu, arm-linux-gnu, sparc64-linux-gnu, and
s390x-linux-gnu.
Reviewed-by: Fangrui Song <maskray@google.com>
Diffstat (limited to 'elf/get-dynamic-info.h')
| -rw-r--r-- | elf/get-dynamic-info.h | 25 |
1 files changed, 14 insertions, 11 deletions
diff --git a/elf/get-dynamic-info.h b/elf/get-dynamic-info.h index 15c316b38c..d169099fbc 100644 --- a/elf/get-dynamic-info.h +++ b/elf/get-dynamic-info.h @@ -25,7 +25,7 @@ #include <libc-diag.h> static inline void __attribute__ ((unused, always_inline)) -elf_get_dynamic_info (struct link_map *l) +elf_get_dynamic_info (struct link_map *l, bool check) { #if __ELF_NATIVE_CLASS == 32 typedef Elf32_Word d_tag_utype; @@ -112,16 +112,19 @@ elf_get_dynamic_info (struct link_map *l) assert (info[DT_RELENT]->d_un.d_val == sizeof (ElfW(Rel))); #endif #ifdef RTLD_BOOTSTRAP - /* Only the bind now flags are allowed. */ - assert (info[VERSYMIDX (DT_FLAGS_1)] == NULL - || (info[VERSYMIDX (DT_FLAGS_1)]->d_un.d_val & ~DF_1_NOW) == 0); - /* Flags must not be set for ld.so. */ - assert (info[DT_FLAGS] == NULL - || (info[DT_FLAGS]->d_un.d_val & ~DF_BIND_NOW) == 0); -#endif -#if defined RTLD_BOOTSTRAP || defined STATIC_PIE_BOOTSTRAP - assert (info[DT_RUNPATH] == NULL); - assert (info[DT_RPATH] == NULL); + if (check) + { + /* Only the bind now flags are allowed. */ + assert (info[VERSYMIDX (DT_FLAGS_1)] == NULL + || (info[VERSYMIDX (DT_FLAGS_1)]->d_un.d_val & ~DF_1_NOW) == 0); + /* Flags must not be set for ld.so. */ + assert (info[DT_FLAGS] == NULL + || (info[DT_FLAGS]->d_un.d_val & ~DF_BIND_NOW) == 0); +# ifdef STATIC_PIE_BOOTSTRAP + assert (info[DT_RUNPATH] == NULL); + assert (info[DT_RPATH] == NULL); +# endif + } #else if (info[DT_FLAGS] != NULL) { |