From ebcf45a16ca981c8515f88db94e757cfc6fe4b35 Mon Sep 17 00:00:00 2001 From: Florian Weimer Date: Fri, 12 Feb 2021 18:22:59 +0100 Subject: [PATCH] elf: Do not copy vDSO soname when setting up link map The kernel does not put the vDSO at special addresses, so writev can write the name directly. Also remove the incorrect comment about not setting l_name. Andy Lutomirski confirmed in that this copy is not necessary. Reviewed-by: Adhemerval Zanella --- elf/setup-vdso.h | 17 +++++------------ 1 file changed, 5 insertions(+), 12 deletions(-) diff --git a/elf/setup-vdso.h b/elf/setup-vdso.h index ece840df38c..86c491e49c9 100644 --- a/elf/setup-vdso.h +++ b/elf/setup-vdso.h @@ -80,20 +80,13 @@ setup_vdso (struct link_map *main_map __attribute__ ((unused)), l->l_local_scope[0]->r_list = &l->l_real; /* Now that we have the info handy, use the DSO image's soname - so this object can be looked up by name. Note that we do not - set l_name here. That field gives the file name of the DSO, - and this DSO is not associated with any file. */ + so this object can be looked up by name. */ if (l->l_info[DT_SONAME] != NULL) { - /* Work around a kernel problem. The kernel cannot handle - addresses in the vsyscall DSO pages in writev() calls. */ - const char *dsoname = ((char *) D_PTR (l, l_info[DT_STRTAB]) - + l->l_info[DT_SONAME]->d_un.d_val); - size_t len = strlen (dsoname) + 1; - char *copy = malloc (len); - if (copy == NULL) - _dl_fatal_printf ("out of memory\n"); - l->l_libname->name = l->l_name = memcpy (copy, dsoname, len); + char *dsoname = ((char *) D_PTR (l, l_info[DT_STRTAB]) + + l->l_info[DT_SONAME]->d_un.d_val); + l->l_libname->name = dsoname; + l->l_name = dsoname; } /* Add the vDSO to the object list. */ -- 2.47.2