+ 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

+ 

+ Release: 4%{?dist}

+ # fix conflict with fakechroot (https://github.com/dex4er/fakechroot/issues/57)

+ Patch2:  0002-attr-2.4.48-switch-back-to-syscall.patch

+ * 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)

+