From c88ffc239e8d8820f6d1d4e185984e6093a1e4d7 Mon Sep 17 00:00:00 2001 From: Florian Weimer Date: Mon, 14 Aug 2017 17:12:05 +0200 Subject: NSS: Replace exported NSS lookup functions with stubs [BZ #21962] Commit 384ca551743318bd9c9e24a496d6397f2e3f2a49 from 2007 added this to nss/XXX-lookup.c: +#ifndef NO_COMPAT +int +internal_function attribute_compat_text_section +DB_COMPAT_FCT (service_user **ni, const char *fct_name, void **fctp) +{ + return DB_LOOKUP_FCT (ni, fct_name, NULL, fctp); +} +#endif That is, it adds a pseudo-compat function with an internal_function attribute. The function it was supposed to replace did not have the attribute: extern int DB_LOOKUP_FCT (service_user **ni, const char *fct_name, - void **fctp) internal_function; + const char *fct2_name, void **fctp) + internal_function; This changed the calling convention on i386 for the following functions in the public ABI: __nss_passwd_lookup __nss_group_lookup __nss_hosts_lookup This commit replaces the functions with always-failing stubs, with true compat symbols. Due to a happy accident, the calling convention of the stub is identical for the internal_function and non-internal_function case on i386. In addition, this commit auto-generates the __nss_*_lookup2 function declarations as part of . --- nss/Makefile | 3 ++- nss/Versions | 2 ++ nss/XXX-lookup.c | 15 --------------- nss/compat-lookup.c | 42 ++++++++++++++++++++++++++++++++++++++++++ nss/nsswitch.h | 8 ++++++++ nss/service-lookup.c | 1 - 6 files changed, 54 insertions(+), 17 deletions(-) create mode 100644 nss/compat-lookup.c (limited to 'nss') diff --git a/nss/Makefile b/nss/Makefile index d9f6d41181..1e298c28f1 100644 --- a/nss/Makefile +++ b/nss/Makefile @@ -27,7 +27,8 @@ headers := nss.h # This is the trivial part which goes into libc itself. routines = nsswitch getnssent getnssent_r digits_dots \ valid_field valid_list_field rewrite_field \ - $(addsuffix -lookup,$(databases)) + $(addsuffix -lookup,$(databases)) \ + compat-lookup # These are the databases that go through nss dispatch. # Caution: if you add a database here, you must add its real name diff --git a/nss/Versions b/nss/Versions index f8ababccc7..50268ed9b5 100644 --- a/nss/Versions +++ b/nss/Versions @@ -7,6 +7,8 @@ libc { GLIBC_2.2.2 { __nss_hostname_digits_dots; } + GLIBC_2.27 { + } GLIBC_PRIVATE { _nss_files_parse_grent; _nss_files_parse_pwent; _nss_files_parse_spent; __nss_disable_nscd; __nss_lookup_function; _nss_files_parse_sgent; diff --git a/nss/XXX-lookup.c b/nss/XXX-lookup.c index 972a2102bf..49417691b2 100644 --- a/nss/XXX-lookup.c +++ b/nss/XXX-lookup.c @@ -34,7 +34,6 @@ \*******************************************************************/ #define DB_LOOKUP_FCT CONCAT3_1 (__nss_, DATABASE_NAME, _lookup2) -#define DB_COMPAT_FCT CONCAT3_1 (__nss_, DATABASE_NAME, _lookup) #define CONCAT3_1(Pre, Name, Post) CONCAT3_2 (Pre, Name, Post) #define CONCAT3_2(Pre, Name, Post) Pre##Name##Post @@ -55,10 +54,6 @@ service_user *DATABASE_NAME_SYMBOL attribute_hidden; -extern int DB_LOOKUP_FCT (service_user **ni, const char *fct_name, - const char *fct2_name, void **fctp); -libc_hidden_proto (DB_LOOKUP_FCT) - int DB_LOOKUP_FCT (service_user **ni, const char *fct_name, const char *fct2_name, void **fctp) @@ -73,13 +68,3 @@ DB_LOOKUP_FCT (service_user **ni, const char *fct_name, const char *fct2_name, return __nss_lookup (ni, fct_name, fct2_name, fctp); } libc_hidden_def (DB_LOOKUP_FCT) - - -#ifndef NO_COMPAT -int -attribute_compat_text_section -DB_COMPAT_FCT (service_user **ni, const char *fct_name, void **fctp) -{ - return DB_LOOKUP_FCT (ni, fct_name, NULL, fctp); -} -#endif diff --git a/nss/compat-lookup.c b/nss/compat-lookup.c new file mode 100644 index 0000000000..b5c9673b49 --- /dev/null +++ b/nss/compat-lookup.c @@ -0,0 +1,42 @@ +/* Compatibility stubs of accidentally exported __nss_*_lookup functions. + Copyright (C) 2017 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + . */ + +#include +#if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_27) + +# include +# include + +/* On i386, the function calling convention changed from the standard + ABI calling convention to three register parameters in glibc 2.8. + The following error-returning stub happens to be compatible with + glibc 2.7 and earlier and glibc 2.8 and later, even on i386. */ +int +attribute_compat_text_section +__nss_passwd_lookup (service_user **ni, const char *fct_name, void **fctp) +{ + __set_errno (ENOSYS); + return -1; +} +compat_symbol (libc, __nss_passwd_lookup, __nss_passwd_lookup, GLIBC_2_0); +strong_alias (__nss_passwd_lookup, __nss_group_lookup) +compat_symbol (libc, __nss_group_lookup, __nss_group_lookup, GLIBC_2_0); +strong_alias (__nss_passwd_lookup, __nss_hosts_lookup) +compat_symbol (libc, __nss_hosts_lookup, __nss_hosts_lookup, GLIBC_2_0); + +#endif /* SHLIB_COMPAT */ diff --git a/nss/nsswitch.h b/nss/nsswitch.h index 7da90130ec..2b86d63ddb 100644 --- a/nss/nsswitch.h +++ b/nss/nsswitch.h @@ -219,4 +219,12 @@ libc_hidden_proto (__nss_hostname_digits_dots) #define MAX_NR_ALIASES 48 #define MAX_NR_ADDRS 48 +/* Prototypes for __nss_*_lookup2 functions. */ +#define DEFINE_DATABASE(arg) \ + int __nss_##arg##_lookup2 (service_user **, const char *, \ + const char *, void **); \ + libc_hidden_proto (__nss_##arg##_lookup2) +#include "databases.def" +#undef DEFINE_DATABASE + #endif /* nsswitch.h */ diff --git a/nss/service-lookup.c b/nss/service-lookup.c index 3f230d606a..3b97b419b6 100644 --- a/nss/service-lookup.c +++ b/nss/service-lookup.c @@ -17,6 +17,5 @@ . */ #define DATABASE_NAME services -#define NO_COMPAT #include "XXX-lookup.c" -- cgit v1.2.3