Re: [PATCH] Implement non-trivial std::random_device::entropy (PR libstdc++/67578)

2017-05-23 Thread Jonathan Wakely 

On 22/05/17 22:10 +0800, Xi Ruoyao wrote:

In very old Linux kernel (1.3.x) there is random.h but not RNDGETENTCNT.
The random.h without RNDGETENTCNT was only used in the kernel internally.
But at that time Linux Makefile didn't have "headers_install" target
so user may copy all headers (including the internal ones) to /usr/include.
It seems we should check RNDGETENTCNT explicitly if we want to support
1.3.x.


OK, I think that's ancient enough that we don't need to care about it,
but on the other hand it's not impossible to believe that somebody
could be using a custom Linux kernel that removed it. So let's keep
the test for it.

Re: [PATCH] Implement non-trivial std::random_device::entropy (PR libstdc++/67578)

2017-05-22 Thread Xi Ruoyao 
On 2017-05-22 14:50 +0100, Jonathan Wakely wrote:
> On 22/05/17 21:41 +0800, Xi Ruoyao wrote:
> > On 2017-05-22 14:00 +0100, Jonathan Wakely wrote:
> > > On 18/05/17 19:27 +0800, Xi Ruoyao wrote:
> > > > This patch use ioctl to get entropy of std::random_device using
> > > > /dev/random and /dev/urandom.
> > > 
> > > This is a nice addition, thanks.
> > > 
> > > N.B. I couldn't apply your patch, several lines had U+00A0 (i.e.
> > > NO-BREAK SPACE) characters where normal spaces should be. I don't know
> > > if this is something your mail client did, but maybe attaching the
> > > patch as a multipart message rather than including it inline in the
> > > body will prevent it in future.
> > 
> > Oh no...  Seems my email client destroyed my patch. I'll attach the
> > patch next time.  Please wait for PATCH v2.
> 
> OK, will do. I missed part of the required changes when adding a new
> symbol version, see the attached patch.
> 

In very old Linux kernel (1.3.x) there is random.h but not RNDGETENTCNT.
The random.h without RNDGETENTCNT was only used in the kernel internally.
But at that time Linux Makefile didn't have "headers_install" target
so user may copy all headers (including the internal ones) to /usr/include.
It seems we should check RNDGETENTCNT explicitly if we want to support
1.3.x.
-- 
Xi Ruoyao 
School of Aerospace Science and Technology, Xidian University

Re: [PATCH] Implement non-trivial std::random_device::entropy (PR libstdc++/67578)

2017-05-22 Thread Jonathan Wakely 

On 22/05/17 21:41 +0800, Xi Ruoyao wrote:

On 2017-05-22 14:00 +0100, Jonathan Wakely wrote:

On 18/05/17 19:27 +0800, Xi Ruoyao wrote:
> This patch use ioctl to get entropy of std::random_device using
> /dev/random and /dev/urandom.

This is a nice addition, thanks.

N.B. I couldn't apply your patch, several lines had U+00A0 (i.e.
NO-BREAK SPACE) characters where normal spaces should be. I don't know
if this is something your mail client did, but maybe attaching the
patch as a multipart message rather than including it inline in the
body will prevent it in future.


Oh no...  Seems my email client destroyed my patch. I'll attach the
patch next time.  Please wait for PATCH v2.


OK, will do. I missed part of the required changes when adding a new
symbol version, see the attached patch.


diff --git a/libstdc++-v3/testsuite/util/testsuite_abi.cc b/libstdc++-v3/testsuite/util/testsuite_abi.cc
index 953c907..ee7572e 100644
--- a/libstdc++-v3/testsuite/util/testsuite_abi.cc
+++ b/libstdc++-v3/testsuite/util/testsuite_abi.cc
@@ -235,7 +235,7 @@ check_version(symbol& test, bool added)
 	test.version_status = symbol::incompatible;
 
   // Check that added symbols are added in the latest pre-release version.
-  bool latestp = (test.version_name == "GLIBCXX_3.4.23"
+  bool latestp = (test.version_name == "GLIBCXX_3.4.24"
 		 || test.version_name == "CXXABI_1.3.11"
 		 || test.version_name == "CXXABI_FLOAT128"
 		 || test.version_name == "CXXABI_TM_1");

Re: [PATCH] Implement non-trivial std::random_device::entropy (PR libstdc++/67578)

2017-05-22 Thread Xi Ruoyao 
On 2017-05-22 14:00 +0100, Jonathan Wakely wrote:
> On 18/05/17 19:27 +0800, Xi Ruoyao wrote:
> > This patch use ioctl to get entropy of std::random_device using
> > /dev/random and /dev/urandom.
> 
> This is a nice addition, thanks.
> 
> N.B. I couldn't apply your patch, several lines had U+00A0 (i.e.
> NO-BREAK SPACE) characters where normal spaces should be. I don't know
> if this is something your mail client did, but maybe attaching the
> patch as a multipart message rather than including it inline in the
> body will prevent it in future.

Oh no...  Seems my email client destroyed my patch. I'll attach the
patch next time.  Please wait for PATCH v2.

> > diff --git a/libstdc++-v3/config/abi/pre/gnu.ver 
> > b/libstdc++-v3/config/abi/pre/gnu.ver
> > index 3e6e70b..39ad330 100644
> > --- a/libstdc++-v3/config/abi/pre/gnu.ver
> > +++ b/libstdc++-v3/config/abi/pre/gnu.ver
> > @@ -1963,6 +1963,9 @@ GLIBCXX_3.4.23 {
> >  _ZNSt13__future_base13_State_baseV211_Make_ready6_M_setEv;
> >  #endif
> >  
> > +# std::random_device::_M_getentropy() const
> > +_ZNKSt13random_device13_M_getentropyEv;
> > +
> >  } GLIBCXX_3.4.22;
> 
> The 3.4.23 version is now "closed" because it was used for the GCC 7.1
> release, and so we can't add new symbols to it. That means we need to
> bump the library version and create a new GLIBCXX_3.4.24 version node.
> The required steps are documented in doc/xml/manual/build_hacking.xml
> (and done by the attached patch which I'm testing).

I'll do it.  Glad to add the first symbol in 3.4.24.

> > @@ -161,6 +169,34 @@ namespace std _GLIBCXX_VISIBILITY(default)
> >  return _M_mt();
> >    }
> >  
> > +  double
> > +  random_device::_M_getentropy() const noexcept
> > +  {
> > +#if defined _GLIBCXX_HAVE_SYS_IOCTL_H && \
> > +defined _GLIBCXX_HAVE_LINUX_RANDOM_H
> 
> Is RNDGETENTCNT guaranteed to be defined by all versions of
> ?
> 
> Would it be better to check for it explicitly? i.e.
> 
> #if defined _GLIBCXX_HAVE_SYS_IOCTL_H && defined RNDGETENTCNT

It has been there since the git repo of Linux kernel was created.
I have to check the ancient history of kernel code to know.

> 
> It would also be nice to have a test for this functionality, but since
> the available entropy might be zero sometimes we can't guarantee that
> a test for a non-zero value will always pass.

I've thought about it, but I couldn't find out how to do the test.
-- 
Xi Ruoyao 
School of Aerospace Science and Technology, Xidian University

Re: [PATCH] Implement non-trivial std::random_device::entropy (PR libstdc++/67578)

2017-05-22 Thread Jonathan Wakely 

On 18/05/17 19:27 +0800, Xi Ruoyao wrote:

This patch use ioctl to get entropy of std::random_device using
/dev/random and /dev/urandom.


This is a nice addition, thanks.

N.B. I couldn't apply your patch, several lines had U+00A0 (i.e.
NO-BREAK SPACE) characters where normal spaces should be. I don't know
if this is something your mail client did, but maybe attaching the
patch as a multipart message rather than including it inline in the
body will prevent it in future.


diff --git a/libstdc++-v3/config/abi/pre/gnu.ver 
b/libstdc++-v3/config/abi/pre/gnu.ver
index 3e6e70b..39ad330 100644
--- a/libstdc++-v3/config/abi/pre/gnu.ver
+++ b/libstdc++-v3/config/abi/pre/gnu.ver
@@ -1963,6 +1963,9 @@ GLIBCXX_3.4.23 {
 _ZNSt13__future_base13_State_baseV211_Make_ready6_M_setEv;
 #endif
 
+# std::random_device::_M_getentropy() const
+_ZNKSt13random_device13_M_getentropyEv;
+
 } GLIBCXX_3.4.22;


The 3.4.23 version is now "closed" because it was used for the GCC 7.1
release, and so we can't add new symbols to it. That means we need to
bump the library version and create a new GLIBCXX_3.4.24 version node.
The required steps are documented in doc/xml/manual/build_hacking.xml
(and done by the attached patch which I'm testing).


@@ -161,6 +169,34 @@ namespace std _GLIBCXX_VISIBILITY(default)
 return _M_mt();
   }
 
+  double
+  random_device::_M_getentropy() const noexcept
+  {
+#if defined _GLIBCXX_HAVE_SYS_IOCTL_H && \
+defined _GLIBCXX_HAVE_LINUX_RANDOM_H


Is RNDGETENTCNT guaranteed to be defined by all versions of
?

Would it be better to check for it explicitly? i.e.

#if defined _GLIBCXX_HAVE_SYS_IOCTL_H && defined RNDGETENTCNT


It would also be nice to have a test for this functionality, but since
the available entropy might be zero sometimes we can't guarantee that
a test for a non-zero value will always pass.

commit 2e6f7939b6ab2ac0e25af6fc57085bcef8381d04
Author: Jonathan Wakely 
Date:   Mon May 22 13:36:53 2017 +0100

PR libstdc++/67578 Implement non-trivial std::random_device::entropy

2017-05-22  Xi Ruoyao  
	Jonathan Wakely  

	PR libstdc++/67578
	* acinclude.m4: Bump libtool_VERSION.
	* config/abi/pre/gnu.ver: Add GLIBCXX_3.4.23 with new symbol.
	* config.h.in: Regenerate.
	* configure: Regenerate.
	* configure.ac: Add test for .
	* doc/xml/manual/abi.xml: Document new library version.
	* include/bits/random.h (random_device::entropy)
	[_GLIBCXX_USE_RANDOM_TR1]: Add call to new _M_getentropy member.
	(random_device::_M_getentropy): Declare.
	* src/c++11/random.cc (random_device::_M_getentropy): Define.
	* testsuite/util/testsuite_abi.cc: Add GLIBCXX_3.4.24 to known
	versions.

diff --git a/libstdc++-v3/acinclude.m4 b/libstdc++-v3/acinclude.m4
index 61c8cb2..baeea67 100644
--- a/libstdc++-v3/acinclude.m4
+++ b/libstdc++-v3/acinclude.m4
@@ -3750,7 +3750,7 @@ changequote([,])dnl
 fi
 
 # For libtool versioning info, format is CURRENT:REVISION:AGE
-libtool_VERSION=6:23:0
+libtool_VERSION=6:24:0
 
 # Everything parsed; figure out what files and settings to use.
 case $enable_symvers in
diff --git a/libstdc++-v3/config/abi/pre/gnu.ver b/libstdc++-v3/config/abi/pre/gnu.ver
index 268fb94..48e2ec8 100644
--- a/libstdc++-v3/config/abi/pre/gnu.ver
+++ b/libstdc++-v3/config/abi/pre/gnu.ver
@@ -1967,6 +1967,13 @@ GLIBCXX_3.4.23 {
 
 } GLIBCXX_3.4.22;
 
+GLIBCXX_3.4.24 {
+
+# std::random_device::_M_getentropy() const
+_ZNKSt13random_device13_M_getentropyEv;
+
+} GLIBCXX_3.4.23;
+
 # Symbols in the support library (libsupc++) have their own tag.
 CXXABI_1.3 {
 
diff --git a/libstdc++-v3/configure.ac b/libstdc++-v3/configure.ac
index 8e97350..270dcba 100644
--- a/libstdc++-v3/configure.ac
+++ b/libstdc++-v3/configure.ac
@@ -237,7 +237,7 @@ AC_CHECK_HEADERS([endian.h execinfo.h float.h fp.h ieeefp.h inttypes.h \
 locale.h machine/endian.h machine/param.h nan.h stdint.h stdlib.h string.h \
 strings.h sys/ipc.h sys/isa_defs.h sys/machine.h sys/param.h \
 sys/resource.h sys/sem.h sys/stat.h sys/time.h sys/types.h unistd.h \
-wchar.h wctype.h])
+wchar.h wctype.h linux/random.h])
 
 # Only do link tests if native. Else, hardcode.
 if $GLIBCXX_IS_NATIVE; then
diff --git a/libstdc++-v3/doc/xml/manual/abi.xml b/libstdc++-v3/doc/xml/manual/abi.xml
index d086d9e..de8e66c 100644
--- a/libstdc++-v3/doc/xml/manual/abi.xml
+++ b/libstdc++-v3/doc/xml/manual/abi.xml
@@ -266,6 +266,7 @@ compatible.
 GCC 5.1.0: libstdc++.so.6.0.21
 GCC 6.1.0: libstdc++.so.6.0.22
 GCC 7.1.0: libstdc++.so.6.0.23
+GCC 8.0.0: libstdc++.so.6.0.24
 
 
   Note 1: Error should be libstdc++.so.3.0.3.
@@ -334,6 +335,7 @@ compatible.
 GCC 5.1.0: GLIBCXX_3.4.21, CXXABI_1.3.9
 GCC 6.1.0: GLIBCXX_3.4.22, CXXABI_1.3.10
 GCC 7.1.0: GLIBCXX_3.4.23, CXXABI_1.3.11
+GCC 8.0.0: GLIBCXX_3.4.24, CXXABI_1.3.10
 
 
 
diff --git

[PATCH] Implement non-trivial std::random_device::entropy (PR libstdc++/67578)

2017-05-18 Thread Xi Ruoyao 
This patch use ioctl to get entropy of std::random_device using
/dev/random and /dev/urandom.

Regenerated files are mentioned in ChangeLog but not included
in the patch.

2017-03-12  Xi Ruoyao  

PR libstdc++/67578
* config.h.in: Regenerate.
* configure: Regenerate.
* configure.ac: Check for linux/random.h.
* config/abi/pre/gnu.ver: Add a new symbol.
* include/bits/random.h (random_device::_M_getentropy):
  Declare new function to get entropy using ioctl.
  (random_device::entropy): Call it.
* src/c++11/random.cc (random_device::_M_getentropy):
  Implement new function.
* config/abi/post/x86_64-linux-gnu/baseline_symbols.txt:
  Regenerate.
* config/abi/post/i386-linux-gnu/baseline_symbols.txt:
  Regenerate.
* config/abi/post/i486-linux-gnu/baseline_symbols.txt:
  Regenerate.
---
 libstdc++-v3/config/abi/pre/gnu.ver|  3 ++
 libstdc++-v3/configure.ac  |  2 +-
 libstdc++-v3/include/bits/random.h |  9 +-
 libstdc++-v3/src/c++11/random.cc   | 36 ++
 9 files changed, 55 insertions(+), 3 deletions(-)

diff --git a/libstdc++-v3/config/abi/pre/gnu.ver 
b/libstdc++-v3/config/abi/pre/gnu.ver
index 3e6e70b..39ad330 100644
--- a/libstdc++-v3/config/abi/pre/gnu.ver
+++ b/libstdc++-v3/config/abi/pre/gnu.ver
@@ -1963,6 +1963,9 @@ GLIBCXX_3.4.23 {
 _ZNSt13__future_base13_State_baseV211_Make_ready6_M_setEv;
 #endif
 
+# std::random_device::_M_getentropy() const
+_ZNKSt13random_device13_M_getentropyEv;
+
 } GLIBCXX_3.4.22;
 
 # Symbols in the support library (libsupc++) have their own tag.
diff --git a/libstdc++-v3/configure.ac b/libstdc++-v3/configure.ac
index 8e97350..270dcba 100644
--- a/libstdc++-v3/configure.ac
+++ b/libstdc++-v3/configure.ac
@@ -237,7 +237,7 @@ AC_CHECK_HEADERS([endian.h execinfo.h float.h fp.h ieeefp.h 
inttypes.h \
 locale.h machine/endian.h machine/param.h nan.h stdint.h stdlib.h string.h \
 strings.h sys/ipc.h sys/isa_defs.h sys/machine.h sys/param.h \
 sys/resource.h sys/sem.h sys/stat.h sys/time.h sys/types.h unistd.h \
-wchar.h wctype.h])
+wchar.h wctype.h linux/random.h])
 
 # Only do link tests if native. Else, hardcode.
 if $GLIBCXX_IS_NATIVE; then
diff --git a/libstdc++-v3/include/bits/random.h 
b/libstdc++-v3/include/bits/random.h
index d39cc3e..bb761ec 100644
--- a/libstdc++-v3/include/bits/random.h
+++ b/libstdc++-v3/include/bits/random.h
@@ -1603,7 +1603,13 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 
 double
 entropy() const noexcept
-{ return 0.0; }
+{
+#ifdef _GLIBCXX_USE_RANDOM_TR1
+  return this->_M_getentropy();
+#else
+  return 0.0;
+#endif
+}
 
 result_type
 operator()()
@@ -1627,6 +1633,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 
 result_type _M_getval();
 result_type _M_getval_pretr1();
+double _M_getentropy() const noexcept;
 
 union
 {
diff --git a/libstdc++-v3/src/c++11/random.cc b/libstdc++-v3/src/c++11/random.cc
index df79874..414ddc3 100644
--- a/libstdc++-v3/src/c++11/random.cc
+++ b/libstdc++-v3/src/c++11/random.cc
@@ -38,6 +38,14 @@
 # include 
 #endif
 
+#ifdef _GLIBCXX_HAVE_SYS_IOCTL_H
+# include 
+#endif
+
+#ifdef _GLIBCXX_HAVE_LINUX_RANDOM_H
+# include 
+#endif
+
 namespace std _GLIBCXX_VISIBILITY(default)
 {
   namespace
@@ -161,6 +169,34 @@ namespace std _GLIBCXX_VISIBILITY(default)
 return _M_mt();
   }
 
+  double
+  random_device::_M_getentropy() const noexcept
+  {
+#if defined _GLIBCXX_HAVE_SYS_IOCTL_H && \
+defined _GLIBCXX_HAVE_LINUX_RANDOM_H
+if (!_M_file)
+  return 0.0;
+
+int fd = fileno(static_cast(_M_file));
+if (fd < 0)
+  return 0.0;
+
+int ent;
+if (ioctl(fd, RNDGETENTCNT, ) < 0)
+  return 0.0;
+
+if (ent < 0)
+  return 0.0;
+
+if (static_cast(ent) > sizeof(result_type) * 8)
+  return static_cast(sizeof(result_type) * 8);
+
+return static_cast(ent);
+#else
+return 0.0;
+#endif
+  }
+
   template class mersenne_twister_engine<
 uint_fast32_t,
 32, 624, 397, 31,
-- 
2.7.1

-- 
Xi Ruoyao 
School of Aerospace Science and Technology, Xidian University