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| author | Florian Weimer <fweimer@redhat.com> | 2021-06-03 08:26:04 +0200 |
|---|---|---|
| committer | Florian Weimer <fweimer@redhat.com> | 2021-06-03 09:12:05 +0200 |
| commit | 466c1ea15f461edb8e3ffaf5d86d708876343bbf (patch) | |
| tree | 43d42d322ff24bd12c4124a9edafc4e0e4232f0a /include | |
| parent | 9c76debc983e1a16e2e723b36526826713a671af (diff) | |
| download | glibc-466c1ea15f461edb8e3ffaf5d86d708876343bbf.tar glibc-466c1ea15f461edb8e3ffaf5d86d708876343bbf.tar.gz glibc-466c1ea15f461edb8e3ffaf5d86d708876343bbf.tar.bz2 glibc-466c1ea15f461edb8e3ffaf5d86d708876343bbf.zip | |
dlfcn: Rework static dlopen hooks
Consolidate all hooks structures into a single one. There are
no static dlopen ABI concerns because glibc 2.34 already comes
with substantial ABI-incompatible changes in this area. (Static
dlopen requires the exact same dynamic glibc version that was used
for static linking.)
The new approach uses a pointer to the hooks structure into
_rtld_global_ro and initalizes it in __rtld_static_init. This avoids
a back-and-forth with various callback functions.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/dlfcn.h | 31 |
1 files changed, 14 insertions, 17 deletions
diff --git a/include/dlfcn.h b/include/dlfcn.h index 711bbb0f12..d4440c567e 100644 --- a/include/dlfcn.h +++ b/include/dlfcn.h @@ -91,8 +91,12 @@ libc_hidden_proto (_dl_vsym) extern int _dlerror_run (void (*operate) (void *), void *args); libc_hidden_proto (_dlerror_run) +/* This structure is used to make the outer (statically linked) + implementation of dlopen and related functions to the inner libc + after static dlopen, via the GLRO (dl_dlfcn_hook) pointer. */ struct dlfcn_hook { + /* Public interfaces. */ void *(*dlopen) (const char *file, int mode, void *dl_caller); int (*dlclose) (void *handle); void *(*dlsym) (void *handle, const char *name, void *dl_caller); @@ -104,15 +108,17 @@ struct dlfcn_hook void **extra_info, int flags); int (*dlinfo) (void *handle, int request, void *arg); void *(*dlmopen) (Lmid_t nsid, const char *file, int mode, void *dl_caller); - void *pad[4]; -}; -extern struct dlfcn_hook *_dlfcn_hook; -libc_hidden_proto (_dlfcn_hook) + /* Internal interfaces. */ + void* (*libc_dlopen_mode) (const char *__name, int __mode); + void* (*libc_dlsym) (void *map, const char *name); + void* (*libc_dlvsym) (void *map, const char *name, const char *version); + int (*libc_dlclose) (void *map); +}; -/* Note: These prototypes are for initializing _dflcn_hook in static - libraries. Internal calls in glibc should use the __libc_dl* - functions defined in elf/dl-libc.c instead. */ +/* Note: These prototypes are for initializing _dlfcn_hook in static + builds; see __rtld_static_init. Internal calls in glibc should use + the __libc_dl* functions defined in elf/dl-libc.c instead. */ extern void *__dlopen (const char *file, int mode, void *caller); extern void *__dlmopen (Lmid_t nsid, const char *file, int mode, @@ -125,16 +131,7 @@ extern int __dladdr (const void *address, Dl_info *info); extern int __dladdr1 (const void *address, Dl_info *info, void **extra_info, int flags); extern int __dlinfo (void *handle, int request, void *arg); - -#ifndef SHARED -struct link_map; -extern void * __libc_dlsym_private (struct link_map *map, const char *name) - attribute_hidden; -extern void __libc_register_dl_open_hook (struct link_map *map) - attribute_hidden; -extern void __libc_register_dlfcn_hook (struct link_map *map) - attribute_hidden; -#endif +extern char *__dlerror (void); #endif #endif |