Switch compatibility functions back to syscall()

This prevents an issue in interaction of libattr with fakechroot
(https://github.com/dex4er/fakechroot/issues/57)

Signed-off-by: Filipe Brandenburger <filbranden@gmail.com>

0002-attr-2.4.48-switch-back-to-syscall.patch

@@ -0,0 +1,123 @@
+From 14adc898a36948267bfe5c63b399996879e94c98 Mon Sep 17 00:00:00 2001
+From: Andreas Gruenbacher <agruenba@redhat.com>
+Date: Fri, 17 Aug 2018 14:07:31 +0200
+Subject: [PATCH] Switch back to syscall()
+
+Switch back to syscall() for the *xattr system calls.  The current
+mechanism of forwarding those calls to glibc breaks libraries like
+libfakeroot (fakeroot) and libasan (the gcc address sanitizer; gcc
+-fsanitize=address).
+
+Those libraries provide wrappers for functions defined in other shared
+libraries, usually glibc, do their own processing, and forward calls to
+the original symbols looke dup via dlsym(RTLD_NEXT, "symbol_name").  In
+our case, dlsym returns the libattr_*xattr wrappers.  However, when our
+wrappers try calling glibc, they end up calling the libfakeroot /
+libasan wrappers instead because those override the original symbols =>
+recursion.
+
+The libattr_*xattr wrappers will only be used when symbols are looked up
+at runtime (dlopen / dlsym).  Programs linking against libattr will
+directly use the glibc provided symbols.  Therefore, the slightly worse
+performance of syscall() won't affect any of the "normal" users of
+libattr.
+---
+ libattr/syscalls.c | 26 ++++++++++++++------------
+ 1 file changed, 14 insertions(+), 12 deletions(-)
+
+diff --git a/libattr/syscalls.c b/libattr/syscalls.c
+index 3013aa0bb687..721ad7f33185 100644
+--- a/libattr/syscalls.c
++++ b/libattr/syscalls.c
+@@ -22,6 +22,8 @@
+ 
+ #include "config.h"
+ 
++#include <unistd.h>
++#include <sys/syscall.h>
+ #include <sys/xattr.h>
+ 
+ #ifdef HAVE_VISIBILITY_ATTRIBUTE
+@@ -31,67 +33,67 @@
+ int libattr_setxattr(const char *path, const char *name,
+ 		     void *value, size_t size, int flags)
+ {
+-	return setxattr(path, name, value, size, flags);
++	return syscall(__NR_setxattr, path, name, value, size, flags);
+ }
+ 
+ int libattr_lsetxattr(const char *path, const char *name,
+ 		      void *value, size_t size, int flags)
+ {
+-	return lsetxattr(path, name, value, size, flags);
++	return syscall(__NR_lsetxattr, path, name, value, size, flags);
+ }
+ 
+ int libattr_fsetxattr(int filedes, const char *name,
+ 		      void *value, size_t size, int flags)
+ {
+-	return fsetxattr(filedes, name, value, size, flags);
++	return syscall(__NR_fsetxattr, filedes, name, value, size, flags);
+ }
+ 
+ ssize_t libattr_getxattr(const char *path, const char *name,
+ 			 void *value, size_t size)
+ {
+-	return getxattr(path, name, value, size);
++	return syscall(__NR_getxattr, path, name, value, size);
+ }
+ 
+ ssize_t libattr_lgetxattr(const char *path, const char *name,
+ 			  void *value, size_t size)
+ {
+-	return lgetxattr(path, name, value, size);
++	return syscall(__NR_lgetxattr, path, name, value, size);
+ }
+ 
+ ssize_t libattr_fgetxattr(int filedes, const char *name,
+ 			  void *value, size_t size)
+ {
+-	return fgetxattr(filedes, name, value, size);
++	return syscall(__NR_fgetxattr, filedes, name, value, size);
+ }
+ 
+ ssize_t libattr_listxattr(const char *path, char *list, size_t size)
+ {
+-	return listxattr(path, list, size);
++	return syscall(__NR_listxattr, path, list, size);
+ }
+ 
+ ssize_t libattr_llistxattr(const char *path, char *list, size_t size)
+ {
+-	return llistxattr(path, list, size);
++	return syscall(__NR_llistxattr, path, list, size);
+ }
+ 
+ ssize_t libattr_flistxattr(int filedes, char *list, size_t size)
+ {
+-	return flistxattr(filedes, list, size);
++	return syscall(__NR_flistxattr, filedes, list, size);
+ }
+ 
+ int libattr_removexattr(const char *path, const char *name)
+ {
+-	return removexattr(path, name);
++	return syscall(__NR_removexattr, path, name);
+ }
+ 
+ int libattr_lremovexattr(const char *path, const char *name)
+ {
+-	return lremovexattr(path, name);
++	return syscall(__NR_lremovexattr, path, name);
+ }
+ 
+ int libattr_fremovexattr(int filedes, const char *name)
+ {
+-	return fremovexattr(filedes, name);
++	return syscall(__NR_fremovexattr, filedes, name);
+ }
+ 
+ #ifdef HAVE_VISIBILITY_ATTRIBUTE
+-- 
+2.19.0.rc0
+

attr.spec

@@ -1,11 +1,13 @@
 Summary: Utilities for managing filesystem extended attributes
 Name: attr
 Version: 2.4.48
-Release: 3%{?dist}
+Release: 4%{?dist}
 Source: https://download-mirror.savannah.gnu.org/releases/attr/attr-%{version}.tar.gz
 
 # fix test-suite failure with perl-5.26.0 (#1473853)
 Patch1:  0001-attr-2.4.48-test-suite-perl.patch
+# fix conflict with fakechroot (https://github.com/dex4er/fakechroot/issues/57)
+Patch2:  0002-attr-2.4.48-switch-back-to-syscall.patch
 
 License: GPLv2+
 URL: https://savannah.nongnu.org/projects/attr
@@ -112,6 +114,10 @@ ln -fs ../sys/xattr.h $RPM_BUILD_ROOT%{_includedir}/attr/xattr.h
 %config(noreplace) %{_sysconfdir}/xattr.conf
 
 %changelog
+* Fri Aug 31 2018 Filipe Brandenburger <filbranden@gmail.com> 2.4.48-4
+- Switch compatibility functions back to syscall() to prevent issue in
+  interaction with fakechroot (https://github.com/dex4er/fakechroot/issues/57)
+
 * Tue Jul 17 2018 Kamil Dudka <kdudka@redhat.com> 2.4.48-3
 - temporarily provide attr/xattr.h symlink until users are migrated (#1601482)