[patch added to 3.12-stable] arm64: restore bogomips information in /proc/cpuinfo

[patch added to 3.12-stable] arm64: restore bogomips information in /proc/cpuinfo

[Jiri Slaby]

From: Yang Shi <yang.shi@linaro.org>

This patch has been added to the 3.12 stable tree. If you have any
objections, please let us know.

===============

commit 92e788b749862ebe9920360513a718e5dd4da7a9 upstream.

As previously reported, some userspace applications depend on bogomips
showed by /proc/cpuinfo. Although there is much less legacy impact on
aarch64 than arm, it does break libvirt.

This patch reverts commit 326b16db9f69 ("arm64: delay: don't bother
reporting bogomips in /proc/cpuinfo"), but with some tweak due to
context change and without the pr_info().

Fixes: 326b16db9f69 ("arm64: delay: don't bother reporting bogomips in /proc/cpuinfo")
Signed-off-by: Yang Shi <yang.shi@linaro.org>
Acked-by: Will Deacon <will.deacon@arm.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
 arch/arm64/kernel/setup.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c
index 24bf1563c3bd..59411c933393 100644
--- a/arch/arm64/kernel/setup.c
+++ b/arch/arm64/kernel/setup.c
@@ -365,6 +365,10 @@ static int c_show(struct seq_file *m, void *v)
 		seq_printf(m, "processor\t: %d\n", i);
 #endif
 
+		seq_printf(m, "BogoMIPS\t: %lu.%02lu\n",
+			   loops_per_jiffy / (500000UL/HZ),
+			   loops_per_jiffy / (5000UL/HZ) % 100);
+
 		/*
 		 * Dump out the common processor features in a single line.
 		 * Userspace should read the hwcaps with getauxval(AT_HWCAP)
-- 
2.7.0

[patch added to 3.12-stable] compiler/gcc4+: Remove inaccurate comment about 'asm goto' miscompiles

[Jiri Slaby]

From: Steven Noonan <steven@uplinklabs.net>

This patch has been added to the 3.12 stable tree. If you have any
objections, please let us know.

===============

commit 5631b8fba640a4ab2f8a954f63a603fa34eda96b upstream.

The bug referenced by the comment in this commit was not
completely fixed in GCC 4.8.2, as I mentioned in a thread back
in February:

   https://lkml.org/lkml/2014/2/12/797

The conclusion at that time was to make the quirk unconditional
until the bug could be found and fixed in GCC. Unfortunately,
when I submitted the patch (commit a9f18034) I left a comment
in that claimed the bug was fixed in GCC 4.8.2+.

This comment is inaccurate, and should be removed.

Signed-off-by: Steven Noonan <steven@uplinklabs.net>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Jakub Jelinek <jakub@redhat.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/1414274982-14040-1-git-send-email-steven@uplinklabs.net
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
 include/linux/compiler-gcc4.h | 1 -
 include/linux/compiler-gcc5.h | 1 -
 2 files changed, 2 deletions(-)

diff --git a/include/linux/compiler-gcc4.h b/include/linux/compiler-gcc4.h
index 2507fd2a1eb4..d1a558239b1a 100644
--- a/include/linux/compiler-gcc4.h
+++ b/include/linux/compiler-gcc4.h
@@ -71,7 +71,6 @@
  *   http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58670
  *
  * Work it around via a compiler barrier quirk suggested by Jakub Jelinek.
- * Fixed in GCC 4.8.2 and later versions.
  *
  * (asm goto is automatically volatile - the naming reflects this.)
  */
diff --git a/include/linux/compiler-gcc5.h b/include/linux/compiler-gcc5.h
index cdd1cc202d51..c8c565952548 100644
--- a/include/linux/compiler-gcc5.h
+++ b/include/linux/compiler-gcc5.h
@@ -53,7 +53,6 @@
  *   http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58670
  *
  * Work it around via a compiler barrier quirk suggested by Jakub Jelinek.
- * Fixed in GCC 4.8.2 and later versions.
  *
  * (asm goto is automatically volatile - the naming reflects this.)
  */
-- 
2.7.0

[patch added to 3.12-stable] compiler-gcc: integrate the various compiler-gcc[345].h files

[Jiri Slaby]

From: Joe Perches <joe@perches.com>

This patch has been added to the 3.12 stable tree. If you have any
objections, please let us know.

===============

commit cb984d101b30eb7478d32df56a0023e4603cba7f upstream.

As gcc major version numbers are going to advance rather rapidly in the
future, there's no real value in separate files for each compiler
version.

Deduplicate some of the macros #defined in each file too.

Neaten comments using normal kernel commenting style.

Signed-off-by: Joe Perches <joe@perches.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Michal Marek <mmarek@suse.cz>
Cc: Segher Boessenkool <segher@kernel.crashing.org>
Cc: Sasha Levin <levinsasha928@gmail.com>
Cc: Anton Blanchard <anton@samba.org>
Cc: Alan Modra <amodra@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
 include/linux/compiler-gcc.h  | 114 ++++++++++++++++++++++++++++++++++++++++--
 include/linux/compiler-gcc3.h |  23 ---------
 include/linux/compiler-gcc4.h |  87 --------------------------------
 include/linux/compiler-gcc5.h |  65 ------------------------
 4 files changed, 110 insertions(+), 179 deletions(-)
 delete mode 100644 include/linux/compiler-gcc3.h
 delete mode 100644 include/linux/compiler-gcc4.h
 delete mode 100644 include/linux/compiler-gcc5.h

diff --git a/include/linux/compiler-gcc.h b/include/linux/compiler-gcc.h
index 02ae99e8e6d3..65856c3599b4 100644
--- a/include/linux/compiler-gcc.h
+++ b/include/linux/compiler-gcc.h
@@ -100,10 +100,116 @@
 #define __maybe_unused			__attribute__((unused))
 #define __always_unused			__attribute__((unused))
 
-#define __gcc_header(x) #x
-#define _gcc_header(x) __gcc_header(linux/compiler-gcc##x.h)
-#define gcc_header(x) _gcc_header(x)
-#include gcc_header(__GNUC__)
+/* gcc version specific checks */
+
+#if GCC_VERSION < 30200
+# error Sorry, your compiler is too old - please upgrade it.
+#endif
+
+#if GCC_VERSION < 30300
+# define __used			__attribute__((__unused__))
+#else
+# define __used			__attribute__((__used__))
+#endif
+
+#ifdef CONFIG_GCOV_KERNEL
+# if GCC_VERSION < 30400
+#   error "GCOV profiling support for gcc versions below 3.4 not included"
+# endif /* __GNUC_MINOR__ */
+#endif /* CONFIG_GCOV_KERNEL */
+
+#if GCC_VERSION >= 30400
+#define __must_check		__attribute__((warn_unused_result))
+#endif
+
+#if GCC_VERSION >= 40000
+
+/* GCC 4.1.[01] miscompiles __weak */
+#ifdef __KERNEL__
+# if GCC_VERSION >= 40100 &&  GCC_VERSION <= 40101
+#  error Your version of gcc miscompiles the __weak directive
+# endif
+#endif
+
+#define __used			__attribute__((__used__))
+#define __compiler_offsetof(a, b)					\
+	__builtin_offsetof(a, b)
+
+#if GCC_VERSION >= 40100 && GCC_VERSION < 40600
+# define __compiletime_object_size(obj) __builtin_object_size(obj, 0)
+#endif
+
+#if GCC_VERSION >= 40300
+/* Mark functions as cold. gcc will assume any path leading to a call
+ * to them will be unlikely.  This means a lot of manual unlikely()s
+ * are unnecessary now for any paths leading to the usual suspects
+ * like BUG(), printk(), panic() etc. [but let's keep them for now for
+ * older compilers]
+ *
+ * Early snapshots of gcc 4.3 don't support this and we can't detect this
+ * in the preprocessor, but we can live with this because they're unreleased.
+ * Maketime probing would be overkill here.
+ *
+ * gcc also has a __attribute__((__hot__)) to move hot functions into
+ * a special section, but I don't see any sense in this right now in
+ * the kernel context
+ */
+#define __cold			__attribute__((__cold__))
+
+#define __UNIQUE_ID(prefix) __PASTE(__PASTE(__UNIQUE_ID_, prefix), __COUNTER__)
+
+#ifndef __CHECKER__
+# define __compiletime_warning(message) __attribute__((warning(message)))
+# define __compiletime_error(message) __attribute__((error(message)))
+#endif /* __CHECKER__ */
+#endif /* GCC_VERSION >= 40300 */
+
+#if GCC_VERSION >= 40500
+/*
+ * Mark a position in code as unreachable.  This can be used to
+ * suppress control flow warnings after asm blocks that transfer
+ * control elsewhere.
+ *
+ * Early snapshots of gcc 4.5 don't support this and we can't detect
+ * this in the preprocessor, but we can live with this because they're
+ * unreleased.  Really, we need to have autoconf for the kernel.
+ */
+#define unreachable() __builtin_unreachable()
+
+/* Mark a function definition as prohibited from being cloned. */
+#define __noclone	__attribute__((__noclone__))
+
+#endif /* GCC_VERSION >= 40500 */
+
+#if GCC_VERSION >= 40600
+/*
+ * Tell the optimizer that something else uses this function or variable.
+ */
+#define __visible	__attribute__((externally_visible))
+#endif
+
+/*
+ * GCC 'asm goto' miscompiles certain code sequences:
+ *
+ *   http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58670
+ *
+ * Work it around via a compiler barrier quirk suggested by Jakub Jelinek.
+ *
+ * (asm goto is automatically volatile - the naming reflects this.)
+ */
+#define asm_volatile_goto(x...)	do { asm goto(x); asm (""); } while (0)
+
+#ifdef CONFIG_ARCH_USE_BUILTIN_BSWAP
+#if GCC_VERSION >= 40400
+#define __HAVE_BUILTIN_BSWAP32__
+#define __HAVE_BUILTIN_BSWAP64__
+#endif
+#if GCC_VERSION >= 40800 || (defined(__powerpc__) && GCC_VERSION >= 40600)
+#define __HAVE_BUILTIN_BSWAP16__
+#endif
+#endif /* CONFIG_ARCH_USE_BUILTIN_BSWAP */
+
+#endif	/* gcc version >= 40000 specific checks */
 
 #if !defined(__noclone)
 #define __noclone	/* not needed */
diff --git a/include/linux/compiler-gcc3.h b/include/linux/compiler-gcc3.h
deleted file mode 100644
index 7d89febe4d79..000000000000
--- a/include/linux/compiler-gcc3.h
+++ /dev/null
@@ -1,23 +0,0 @@
-#ifndef __LINUX_COMPILER_H
-#error "Please don't include <linux/compiler-gcc3.h> directly, include <linux/compiler.h> instead."
-#endif
-
-#if GCC_VERSION < 30200
-# error Sorry, your compiler is too old - please upgrade it.
-#endif
-
-#if GCC_VERSION >= 30300
-# define __used			__attribute__((__used__))
-#else
-# define __used			__attribute__((__unused__))
-#endif
-
-#if GCC_VERSION >= 30400
-#define __must_check		__attribute__((warn_unused_result))
-#endif
-
-#ifdef CONFIG_GCOV_KERNEL
-# if GCC_VERSION < 30400
-#   error "GCOV profiling support for gcc versions below 3.4 not included"
-# endif /* __GNUC_MINOR__ */
-#endif /* CONFIG_GCOV_KERNEL */
diff --git a/include/linux/compiler-gcc4.h b/include/linux/compiler-gcc4.h
deleted file mode 100644
index d1a558239b1a..000000000000
--- a/include/linux/compiler-gcc4.h
+++ /dev/null
@@ -1,87 +0,0 @@
-#ifndef __LINUX_COMPILER_H
-#error "Please don't include <linux/compiler-gcc4.h> directly, include <linux/compiler.h> instead."
-#endif
-
-/* GCC 4.1.[01] miscompiles __weak */
-#ifdef __KERNEL__
-# if GCC_VERSION >= 40100 &&  GCC_VERSION <= 40101
-#  error Your version of gcc miscompiles the __weak directive
-# endif
-#endif
-
-#define __used			__attribute__((__used__))
-#define __must_check 		__attribute__((warn_unused_result))
-#define __compiler_offsetof(a,b) __builtin_offsetof(a,b)
-
-#if GCC_VERSION >= 40100 && GCC_VERSION < 40600
-# define __compiletime_object_size(obj) __builtin_object_size(obj, 0)
-#endif
-
-#if GCC_VERSION >= 40300
-/* Mark functions as cold. gcc will assume any path leading to a call
-   to them will be unlikely.  This means a lot of manual unlikely()s
-   are unnecessary now for any paths leading to the usual suspects
-   like BUG(), printk(), panic() etc. [but let's keep them for now for
-   older compilers]
-
-   Early snapshots of gcc 4.3 don't support this and we can't detect this
-   in the preprocessor, but we can live with this because they're unreleased.
-   Maketime probing would be overkill here.
-
-   gcc also has a __attribute__((__hot__)) to move hot functions into
-   a special section, but I don't see any sense in this right now in
-   the kernel context */
-#define __cold			__attribute__((__cold__))
-
-#define __UNIQUE_ID(prefix) __PASTE(__PASTE(__UNIQUE_ID_, prefix), __COUNTER__)
-
-#ifndef __CHECKER__
-# define __compiletime_warning(message) __attribute__((warning(message)))
-# define __compiletime_error(message) __attribute__((error(message)))
-#endif /* __CHECKER__ */
-#endif /* GCC_VERSION >= 40300 */
-
-#if GCC_VERSION >= 40500
-/*
- * Mark a position in code as unreachable.  This can be used to
- * suppress control flow warnings after asm blocks that transfer
- * control elsewhere.
- *
- * Early snapshots of gcc 4.5 don't support this and we can't detect
- * this in the preprocessor, but we can live with this because they're
- * unreleased.  Really, we need to have autoconf for the kernel.
- */
-#define unreachable() __builtin_unreachable()
-
-/* Mark a function definition as prohibited from being cloned. */
-#define __noclone	__attribute__((__noclone__))
-
-#endif /* GCC_VERSION >= 40500 */
-
-#if GCC_VERSION >= 40600
-/*
- * Tell the optimizer that something else uses this function or variable.
- */
-#define __visible __attribute__((externally_visible))
-#endif
-
-/*
- * GCC 'asm goto' miscompiles certain code sequences:
- *
- *   http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58670
- *
- * Work it around via a compiler barrier quirk suggested by Jakub Jelinek.
- *
- * (asm goto is automatically volatile - the naming reflects this.)
- */
-#define asm_volatile_goto(x...)	do { asm goto(x); asm (""); } while (0)
-
-#ifdef CONFIG_ARCH_USE_BUILTIN_BSWAP
-#if GCC_VERSION >= 40400
-#define __HAVE_BUILTIN_BSWAP32__
-#define __HAVE_BUILTIN_BSWAP64__
-#endif
-#if GCC_VERSION >= 40800 || (defined(__powerpc__) && GCC_VERSION >= 40600)
-#define __HAVE_BUILTIN_BSWAP16__
-#endif
-#endif /* CONFIG_ARCH_USE_BUILTIN_BSWAP */
diff --git a/include/linux/compiler-gcc5.h b/include/linux/compiler-gcc5.h
deleted file mode 100644
index c8c565952548..000000000000
--- a/include/linux/compiler-gcc5.h
+++ /dev/null
@@ -1,65 +0,0 @@
-#ifndef __LINUX_COMPILER_H
-#error "Please don't include <linux/compiler-gcc5.h> directly, include <linux/compiler.h> instead."
-#endif
-
-#define __used				__attribute__((__used__))
-#define __must_check			__attribute__((warn_unused_result))
-#define __compiler_offsetof(a, b)	__builtin_offsetof(a, b)
-
-/* Mark functions as cold. gcc will assume any path leading to a call
-   to them will be unlikely.  This means a lot of manual unlikely()s
-   are unnecessary now for any paths leading to the usual suspects
-   like BUG(), printk(), panic() etc. [but let's keep them for now for
-   older compilers]
-
-   Early snapshots of gcc 4.3 don't support this and we can't detect this
-   in the preprocessor, but we can live with this because they're unreleased.
-   Maketime probing would be overkill here.
-
-   gcc also has a __attribute__((__hot__)) to move hot functions into
-   a special section, but I don't see any sense in this right now in
-   the kernel context */
-#define __cold			__attribute__((__cold__))
-
-#define __UNIQUE_ID(prefix) __PASTE(__PASTE(__UNIQUE_ID_, prefix), __COUNTER__)
-
-#ifndef __CHECKER__
-# define __compiletime_warning(message) __attribute__((warning(message)))
-# define __compiletime_error(message) __attribute__((error(message)))
-#endif /* __CHECKER__ */
-
-/*
- * Mark a position in code as unreachable.  This can be used to
- * suppress control flow warnings after asm blocks that transfer
- * control elsewhere.
- *
- * Early snapshots of gcc 4.5 don't support this and we can't detect
- * this in the preprocessor, but we can live with this because they're
- * unreleased.  Really, we need to have autoconf for the kernel.
- */
-#define unreachable() __builtin_unreachable()
-
-/* Mark a function definition as prohibited from being cloned. */
-#define __noclone	__attribute__((__noclone__))
-
-/*
- * Tell the optimizer that something else uses this function or variable.
- */
-#define __visible __attribute__((externally_visible))
-
-/*
- * GCC 'asm goto' miscompiles certain code sequences:
- *
- *   http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58670
- *
- * Work it around via a compiler barrier quirk suggested by Jakub Jelinek.
- *
- * (asm goto is automatically volatile - the naming reflects this.)
- */
-#define asm_volatile_goto(x...)	do { asm goto(x); asm (""); } while (0)
-
-#ifdef CONFIG_ARCH_USE_BUILTIN_BSWAP
-#define __HAVE_BUILTIN_BSWAP32__
-#define __HAVE_BUILTIN_BSWAP64__
-#define __HAVE_BUILTIN_BSWAP16__
-#endif /* CONFIG_ARCH_USE_BUILTIN_BSWAP */
-- 
2.7.0

[patch added to 3.12-stable] x86: vvar, fix excessive gcc-6 DECLARE_VVAR warnings

[Jiri Slaby]

This patch has been added to the 3.12 stable tree. If you have any
objections, please let us know.

===============

On 3.12, with gcc-6, I see a lot of:
arch/x86/include/asm/vvar.h:33:28: warning: ‘vvaraddr_jiffies’ defined but not used [-Wunused-const-variable]
  static type const * const vvaraddr_ ## name =   \
                            ^
arch/x86/include/asm/vvar.h:46:1: note: in expansion of macro ‘DECLARE_VVAR’
 DECLARE_VVAR(0, volatile unsigned long, jiffies)
 ^~~~~~~~~~~~

In upstream, this is fixed by ef721987ae (x86, vdso: Introduce VVAR
marco for vdso32) and f40c330091 (x86, vdso: Move the vvar and hpet
mappings next to the 64-bit vDSO). But this is not applicable to
stable.

So mark the vvar declaration as __maybe_unused and be done with it.
This will generate it to the code only if it is used. I.e. the same as
with gcc < 6.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Andy Lutomirski <luto@amacapital.net>
---
 arch/x86/include/asm/vvar.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/include/asm/vvar.h b/arch/x86/include/asm/vvar.h
index d76ac40da206..9fb01a91c013 100644
--- a/arch/x86/include/asm/vvar.h
+++ b/arch/x86/include/asm/vvar.h
@@ -30,7 +30,7 @@
 #else
 
 #define DECLARE_VVAR(offset, type, name)				\
-	static type const * const vvaraddr_ ## name =			\
+	static type const * const vvaraddr_ ## name __maybe_unused =	\
 		(void *)(VVAR_ADDRESS + (offset));
 
 #define DEFINE_VVAR(type, name)						\
-- 
2.7.0

Re: [patch added to 3.12-stable] compiler/gcc4+: Remove inaccurate comment about 'asm goto' miscompiles

[Jakub Jelinek]

On Thu, Jan 28, 2016 at 11:56:53AM +0100, Jiri Slaby wrote:
> From: Steven Noonan <steven@uplinklabs.net>
> 
> This patch has been added to the 3.12 stable tree. If you have any
> objections, please let us know.
> 
> ===============
> 
> commit 5631b8fba640a4ab2f8a954f63a603fa34eda96b upstream.
> 
> The bug referenced by the comment in this commit was not
> completely fixed in GCC 4.8.2, as I mentioned in a thread back
> in February:
> 
>    https://lkml.org/lkml/2014/2/12/797

If you suspect a GCC bug, better try to narrow it down to a reasonably sized
testcase, preprocess it and file in GCC bugzilla.  Otherwise it will never
be fixed.

	Jakub

Re: [patch added to 3.12-stable] compiler/gcc4+: Remove inaccurate comment about 'asm goto' miscompiles

[Ingo Molnar]

* Jakub Jelinek <jakub@redhat.com> wrote:

> On Thu, Jan 28, 2016 at 11:56:53AM +0100, Jiri Slaby wrote:
> > From: Steven Noonan <steven@uplinklabs.net>
> > 
> > This patch has been added to the 3.12 stable tree. If you have any
> > objections, please let us know.
> > 
> > ===============
> > 
> > commit 5631b8fba640a4ab2f8a954f63a603fa34eda96b upstream.
> > 
> > The bug referenced by the comment in this commit was not
> > completely fixed in GCC 4.8.2, as I mentioned in a thread back
> > in February:
> > 
> >    https://lkml.org/lkml/2014/2/12/797
> 
> If you suspect a GCC bug, better try to narrow it down to a reasonably sized
> testcase, preprocess it and file in GCC bugzilla.  Otherwise it will never
> be fixed.

There's always the hope that someone hits an easier to analyze testcase! ;-)

OTOH the Linux kernel might be one of only a handful of large projects making 
heavy use of 'asm goto', right?

Btw., I think Linus complained at least about the debuggability of this:

  https://lkml.org/lkml/2014/2/12/805

  " [...] But I'm sure Jakub&co would love to have a test-case.

  Sadly, gcc has that really annoying habit of making small changes create *huge* 
  changes in label numbers etc, and that's definitely the case with the extra 
  empty asm - it's basically impossible to compare the generated asm with and 
  without the workaround, because all the label numbers change.

  I have no idea how gcc people debug things like this, when the output is so 
  unstable.

  Jakub, any suggestions to how Steven might be able to pinpoint where the code 
  generation problem lies?

                Linus"

Thanks,

	Ingo