(leaving gcc out, it's really out of the story, it just happens to expose support for ifunc)
Joseph Myers, le lun. 18 janv. 2021 20:05:44 +0000, a ecrit: > /scratch/jmyers/glibc-bot/install/compilers/i686-gnu/lib/gcc/i686-glibc-gnu/11.0.0/../../../../i686-glibc-gnu/bin/ld: > > /scratch/jmyers/glibc-bot/build/compilers/i686-gnu/glibc/i686-gnu/elf/librtld.os: > in function `hurd_file_name_lookup_retry': > (.text+0x1e08e): undefined reference to `strncpy' The story seems complex and related to the glibc rtld build rules. - We need hurd/lookup-retry.c in the rtld - It happens to use strncpy since ee11682d4f5 ("hurd: Fix strcpy calls") - strncpy happens to have a hidden def in libc - hurd/lookup-retry.os thus refers to __GI_strncpy rather than strncpy - dl-allobjs.os thus includes strncpy-c.os (that provides __GI_strncpy), and not strncpy.os (that provides strncpy) - librtld.map thus contains strncpy-c.os only, and not strncpy.os - thus no rtld-strncpy.os is getting built - thus strncpy is not available in rtld - but strncpy doesn't have a hidden def in rtld - and thus hurd/rtld-lookup-retry.os refers to strncpy, not __GI_strncpy - thus the link failure. The base issue I see here is that dl-allobjs is based on libc-built objects that might be using hidden defs while rtld-built objects might not. But we could also say that it's strncpy that should also have a hidden def in rtld. The attached patch does this, is this ok? Samuel
diff --git a/include/libc-symbols.h b/include/libc-symbols.h index ea126ae70c..051d6b9492 100644 --- a/include/libc-symbols.h +++ b/include/libc-symbols.h @@ -856,6 +856,8 @@ for linking") # define HIDDEN_BUILTIN_JUMPTARGET(name) HIDDEN_JUMPTARGET(name) #endif +#define rtld_hidden_builtin_proto(name, attrs...) rtld_hidden_proto (name, ##attrs) + #if IS_IN (libutil) # define libutil_hidden_proto(name, attrs...) hidden_proto (name, ##attrs) # define libutil_hidden_tls_proto(name, attrs...) \ diff --git a/include/string.h b/include/string.h index 81dab39891..27cbde47ef 100644 --- a/include/string.h +++ b/include/string.h @@ -144,6 +144,7 @@ libc_hidden_builtin_proto (strcspn) libc_hidden_builtin_proto (strlen) libc_hidden_builtin_proto (strncmp) libc_hidden_builtin_proto (strncpy) +rtld_hidden_builtin_proto (strncpy) libc_hidden_builtin_proto (strpbrk) libc_hidden_builtin_proto (stpcpy) libc_hidden_builtin_proto (strrchr)