[PATCH] sysctl: convert arch specific unaligned access regulators to generic ones

[PATCH] sysctl: convert arch specific unaligned access regulators to generic ones

[Vineet.Gupta1]

From: Vineet Gupta <vgupta@synopsys.com>

* parisc: /proc/sys/kernel/unaligned-trap => SYSCTL_ARCH_UNALIGN_ALLOW

* ia64: /proc/sys/kernel/ignore-unaligned-usertrap =>
					SYSCTL_ARCH_UNALIGN_NO_WARN

This allows other architectures, specifically ARC to reuse these sysctl
knobs.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Serge Hallyn <serge.hallyn@canonical.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: linux-ia64@vger.kernel.org
Cc: linux-parisc@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
---
 arch/ia64/Kconfig   |    1 +
 arch/parisc/Kconfig |    1 +
 init/Kconfig        |   16 ++++++++++++++++
 kernel/sysctl.c     |   16 +++++++++++++---
 4 files changed, 31 insertions(+), 3 deletions(-)

diff --git a/arch/ia64/Kconfig b/arch/ia64/Kconfig
index 3279646..5fb1064 100644
--- a/arch/ia64/Kconfig
+++ b/arch/ia64/Kconfig
@@ -40,6 +40,7 @@ config IA64
 	select ARCH_THREAD_INFO_ALLOCATOR
 	select ARCH_CLOCKSOURCE_DATA
 	select GENERIC_TIME_VSYSCALL_OLD
+	select SYSCTL_ARCH_UNALIGN_NO_WARN
 	select HAVE_MOD_ARCH_SPECIFIC
 	select MODULES_USE_ELF_RELA
 	default y
diff --git a/arch/parisc/Kconfig b/arch/parisc/Kconfig
index 11def45..7d9de54 100644
--- a/arch/parisc/Kconfig
+++ b/arch/parisc/Kconfig
@@ -20,6 +20,7 @@ config PARISC
 	select ARCH_HAVE_NMI_SAFE_CMPXCHG
 	select GENERIC_SMP_IDLE_THREAD
 	select GENERIC_STRNCPY_FROM_USER
+	select SYSCTL_ARCH_UNALIGN_ALLOW
 	select HAVE_MOD_ARCH_SPECIFIC
 	select MODULES_USE_ELF_RELA
 
diff --git a/init/Kconfig b/init/Kconfig
index 6fdd6e3..de4b184 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -1169,6 +1169,22 @@ config SYSCTL_EXCEPTION_TRACE
 	help
 	  Enable support for /proc/sys/debug/exception-trace.
 
+config SYSCTL_ARCH_UNALIGN_NO_WARN
+	bool
+	help
+	  Enable support for /proc/sys/kernel/ignore-unaligned-usertrap
+	  Allows arch to define/use @no_unaligned_warning to possbly warn about
+	  unaligned access emulation going on under the hood.
+	  see arch/ia64/kernel/unaligned.c for reference
+
+config SYSCTL_ARCH_UNALIGN_ALLOW
+	bool
+	help
+	  Enable support for /proc/sys/kernel/unaligned-trap
+	  Allows arches to define/use @unaligned_enabled to runtime toggle
+	  the unaligned access emulation.
+	  see arch/parisc/kernel/unaligned.c for reference
+
 config KALLSYMS
 	 bool "Load all symbols for debugging/ksymoops" if EXPERT
 	 default y
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 26f65ea..9c618bf 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -157,14 +157,20 @@ extern int sysctl_tsb_ratio;
 
 #ifdef __hppa__
 extern int pwrsw_enabled;
-extern int unaligned_enabled;
 #endif
 
 #ifdef CONFIG_IA64
-extern int no_unaligned_warning;
 extern int unaligned_dump_stack;
 #endif
 
+#ifdef CONFIG_SYSCTL_ARCH_UNALIGN_ALLOW
+extern int unaligned_enabled;
+#endif
+
+#ifdef CONFIG_SYSCTL_ARCH_UNALIGN_NO_WARN
+extern int no_unaligned_warning;
+#endif
+
 #ifdef CONFIG_PROC_SYSCTL
 static int proc_do_cad_pid(struct ctl_table *table, int write,
 		  void __user *buffer, size_t *lenp, loff_t *ppos);
@@ -504,6 +510,8 @@ static struct ctl_table kern_table[] = {
 	 	.mode		= 0644,
 		.proc_handler	= proc_dointvec,
 	},
+#endif
+#ifdef CONFIG_SYSCTL_ARCH_UNALIGN_ALLOW
 	{
 		.procname	= "unaligned-trap",
 		.data		= &unaligned_enabled,
@@ -870,7 +878,7 @@ static struct ctl_table kern_table[] = {
 		.proc_handler	= proc_doulongvec_minmax,
 	},
 #endif
-#ifdef CONFIG_IA64
+#ifdef CONFIG_SYSCTL_ARCH_UNALIGN_NO_WARN
 	{
 		.procname	= "ignore-unaligned-usertrap",
 		.data		= &no_unaligned_warning,
@@ -878,6 +886,8 @@ static struct ctl_table kern_table[] = {
 	 	.mode		= 0644,
 		.proc_handler	= proc_dointvec,
 	},
+#endif
+#ifdef CONFIG_IA64
 	{
 		.procname	= "unaligned-dump-stack",
 		.data		= &unaligned_dump_stack,
-- 
1.7.4.1

[RESEND PATCH] Convert IA64 sysctl to generic

[Vineet Gupta]

Hi,

This came out ARC Port's review by Arnd where he suggested using the existing
sysctl knobs in parisc and/or ia64 for runtime controlling unaligned access
emulation.

Turns out that ARC port needs bit of both.

The common sysctl knobs are now #ifdef based on init/Kconfig options which
the corresponding arches now select in their Kconfigs.
No other arch code is touched (although code has not been compile tested).

If this patch is ACKable, I would request you to please take this patch
via your arch tree - to avoid any merge-hassles and other interdependencies
later.

P.S. I've deliberately NOT added the new items at the end of arch/*/Kconfig,
to avoid any merge conflicts going further - anyhow both the ia64/parisc
Kconfigs are not sorted either.

Thx,
-Vineet

Vineet Gupta (1):
  sysctl: Enable IA64 "ignore-unaligned-usertrap" to be used cross-arch

 arch/ia64/Kconfig |    1 +
 init/Kconfig      |    8 ++++++++
 kernel/sysctl.c   |    9 +++++++--
 3 files changed, 16 insertions(+), 2 deletions(-)

-- 
1.7.4.1

[RESEND PATCH] sysctl: Enable IA64 "ignore-unaligned-usertrap" to be used cross-arch

[Vineet Gupta]

IA64 defines /proc/sys/kernel/ignore-unaligned-usertrap to control
verbosw warnings on unaligned access emaultion.

While the exact menchaincs (ignore/shout) are still arch specific, we
can make the sysctl usable by other arches.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Serge Hallyn <serge.hallyn@canonical.com>
---
 arch/ia64/Kconfig |    1 +
 init/Kconfig      |    8 ++++++++
 kernel/sysctl.c   |    9 +++++++--
 3 files changed, 16 insertions(+), 2 deletions(-)

diff --git a/arch/ia64/Kconfig b/arch/ia64/Kconfig
index 3279646..5fb1064 100644
--- a/arch/ia64/Kconfig
+++ b/arch/ia64/Kconfig
@@ -40,6 +40,7 @@ config IA64
 	select ARCH_THREAD_INFO_ALLOCATOR
 	select ARCH_CLOCKSOURCE_DATA
 	select GENERIC_TIME_VSYSCALL_OLD
+	select SYSCTL_ARCH_UNALIGN_NO_WARN
 	select HAVE_MOD_ARCH_SPECIFIC
 	select MODULES_USE_ELF_RELA
 	default y
diff --git a/init/Kconfig b/init/Kconfig
index 7d30240..e188f9f 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -1232,6 +1232,14 @@ config SYSCTL_EXCEPTION_TRACE
 	help
 	  Enable support for /proc/sys/debug/exception-trace.
 
+config SYSCTL_ARCH_UNALIGN_NO_WARN
+	bool
+	help
+	  Enable support for /proc/sys/kernel/ignore-unaligned-usertrap
+	  Allows arch to define/use @no_unaligned_warning to possbly warn about
+	  unaligned access emulation going on under the hood.
+	  see arch/ia64/kernel/unaligned.c for reference
+
 config KALLSYMS
 	 bool "Load all symbols for debugging/ksymoops" if EXPERT
 	 default y
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index c88878d..840fd5e 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -161,10 +161,13 @@ extern int unaligned_enabled;
 #endif
 
 #ifdef CONFIG_IA64
-extern int no_unaligned_warning;
 extern int unaligned_dump_stack;
 #endif
 
+#ifdef CONFIG_SYSCTL_ARCH_UNALIGN_NO_WARN
+extern int no_unaligned_warning;
+#endif
+
 #ifdef CONFIG_PROC_SYSCTL
 static int proc_do_cad_pid(struct ctl_table *table, int write,
 		  void __user *buffer, size_t *lenp, loff_t *ppos);
@@ -911,7 +914,7 @@ static struct ctl_table kern_table[] = {
 		.proc_handler	= proc_doulongvec_minmax,
 	},
 #endif
-#ifdef CONFIG_IA64
+#ifdef CONFIG_SYSCTL_ARCH_UNALIGN_NO_WARN
 	{
 		.procname	= "ignore-unaligned-usertrap",
 		.data		= &no_unaligned_warning,
@@ -919,6 +922,8 @@ static struct ctl_table kern_table[] = {
 	 	.mode		= 0644,
 		.proc_handler	= proc_dointvec,
 	},
+#endif
+#ifdef CONFIG_IA64
 	{
 		.procname	= "unaligned-dump-stack",
 		.data		= &unaligned_dump_stack,
-- 
1.7.4.1

Re: [RESEND PATCH] sysctl: Enable IA64 "ignore-unaligned-usertrap" to be used cross-arch

[Tony Luck]

On Wed, Jan 2, 2013 at 10:47 PM, Vineet Gupta
<Vineet.Gupta1@synopsys.com> wrote:

> verbosw warnings on unaligned access emaultion.
"verbose", "emulation"

> While the exact menchaincs (ignore/shout) are still arch specific, we
"mechanics"

> +config SYSCTL_ARCH_UNALIGN_NO_WARN
> +       bool
> +       help
> +         Enable support for /proc/sys/kernel/ignore-unaligned-usertrap
> +         Allows arch to define/use @no_unaligned_warning to possbly warn about
"possibly"
> +         unaligned access emulation going on under the hood.
> +         see arch/ia64/kernel/unaligned.c for reference

It doesn't seem right to point users at an ia64 specific file now
that you are making this available to all arches.

-Tony

Re: [RESEND PATCH] sysctl: Enable IA64 "ignore-unaligned-usertrap" to be used cross-arch

[Vineet Gupta]

On Wednesday 09 January 2013 05:13 AM, Tony Luck wrote:
> On Wed, Jan 2, 2013 at 10:47 PM, Vineet Gupta
> <Vineet.Gupta1@synopsys.com> wrote:
>
>
>> +config SYSCTL_ARCH_UNALIGN_NO_WARN
>> +       bool
>> +       help
>> +         Enable support for /proc/sys/kernel/ignore-unaligned-usertrap
>> +         Allows arch to define/use @no_unaligned_warning to possbly warn about
> "possibly"
>> +         unaligned access emulation going on under the hood.
>> +         see arch/ia64/kernel/unaligned.c for reference
> It doesn't seem right to point users at an ia64 specific file now
> that you are making this available to all arches.

The ia64 "reference" is for how the sysctl knob is used - since all we are doing
is moving just the sysctl out of #ifdef ARCH_XYZ.
At any rate, I've removed the line from help. Revised patch to follow.
And as initially requested this will need to go thru IA64-next tree to avoid any
merge dependencies.

TIA,
-Vineet

[PATCH v2] sysctl: Enable IA64 "ignore-unaligned-usertrap" to be used cross-arch

[Vineet Gupta]

IA64 defines /proc/sys/kernel/ignore-unaligned-usertrap to control
verbose warnings on unaligned access emulation.

The exact mechanics of what to do with sysctl (ignore/shout) are arch
specific, this change enables the sysctl to be usable cross-arch.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Serge Hallyn <serge.hallyn@canonical.com>
Cc: linux-ia64@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-arch@vger.kernel.org
---
 arch/ia64/Kconfig |    1 +
 init/Kconfig      |    7 +++++++
 kernel/sysctl.c   |    9 +++++++--
 3 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/arch/ia64/Kconfig b/arch/ia64/Kconfig
index 3279646..5fb1064 100644
--- a/arch/ia64/Kconfig
+++ b/arch/ia64/Kconfig
@@ -40,6 +40,7 @@ config IA64
 	select ARCH_THREAD_INFO_ALLOCATOR
 	select ARCH_CLOCKSOURCE_DATA
 	select GENERIC_TIME_VSYSCALL_OLD
+	select SYSCTL_ARCH_UNALIGN_NO_WARN
 	select HAVE_MOD_ARCH_SPECIFIC
 	select MODULES_USE_ELF_RELA
 	default y
diff --git a/init/Kconfig b/init/Kconfig
index 7d30240..523bee1 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -1232,6 +1232,13 @@ config SYSCTL_EXCEPTION_TRACE
 	help
 	  Enable support for /proc/sys/debug/exception-trace.
 
+config SYSCTL_ARCH_UNALIGN_NO_WARN
+	bool
+	help
+	  Enable support for /proc/sys/kernel/ignore-unaligned-usertrap
+	  Allows arch to define/use @no_unaligned_warning to possibly warn
+	  about unaligned access emulation going on under the hood.
+
 config KALLSYMS
 	 bool "Load all symbols for debugging/ksymoops" if EXPERT
 	 default y
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index c88878d..840fd5e 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -161,10 +161,13 @@ extern int unaligned_enabled;
 #endif
 
 #ifdef CONFIG_IA64
-extern int no_unaligned_warning;
 extern int unaligned_dump_stack;
 #endif
 
+#ifdef CONFIG_SYSCTL_ARCH_UNALIGN_NO_WARN
+extern int no_unaligned_warning;
+#endif
+
 #ifdef CONFIG_PROC_SYSCTL
 static int proc_do_cad_pid(struct ctl_table *table, int write,
 		  void __user *buffer, size_t *lenp, loff_t *ppos);
@@ -911,7 +914,7 @@ static struct ctl_table kern_table[] = {
 		.proc_handler	= proc_doulongvec_minmax,
 	},
 #endif
-#ifdef CONFIG_IA64
+#ifdef CONFIG_SYSCTL_ARCH_UNALIGN_NO_WARN
 	{
 		.procname	= "ignore-unaligned-usertrap",
 		.data		= &no_unaligned_warning,
@@ -919,6 +922,8 @@ static struct ctl_table kern_table[] = {
 	 	.mode		= 0644,
 		.proc_handler	= proc_dointvec,
 	},
+#endif
+#ifdef CONFIG_IA64
 	{
 		.procname	= "unaligned-dump-stack",
 		.data		= &unaligned_dump_stack,
-- 
1.7.4.1

Re: [PATCH v2] sysctl: Enable IA64 "ignore-unaligned-usertrap" to be used cross-arch

[Tony Luck]

Ok. Queued for 3.9 merge window.  It should show up in linux-next in
the next day or two.  We'll see if anyone complains about the name
SYSCTL_ARCH_UNALIGN_NO_WARN (every time I touch the Kconfig
bits it seems that there is some other, better way that we do this now).

-Tony

Re: [PATCH v2] sysctl: Enable IA64 "ignore-unaligned-usertrap" to be used cross-arch

[Eric W. Biederman]

Tony Luck <tony.luck@gmail.com> writes:

> Ok. Queued for 3.9 merge window.  It should show up in linux-next in
> the next day or two.  We'll see if anyone complains about the name
> SYSCTL_ARCH_UNALIGN_NO_WARN (every time I touch the Kconfig
> bits it seems that there is some other, better way that we do this
> now).

The other semi-sane way I could see to do this would be to break the
code out of kernel/sysctl.c into it's own sysctl table and have the
arches that want this sysctl just register it themselves.

Shrug.  It probably isn't worth the effor right now.

Eric

Re: [PATCH v2] sysctl: Enable IA64 "ignore-unaligned-usertrap" to be used cross-arch

[Vineet Gupta]

On Thursday 10 January 2013 12:25 AM, Tony Luck wrote:
> Ok. Queued for 3.9 merge window.  It should show up in linux-next in
> the next day or two.  We'll see if anyone complains about the name
> SYSCTL_ARCH_UNALIGN_NO_WARN (every time I touch the Kconfig
> bits it seems that there is some other, better way that we do this now).
>
> -Tony

Thanks a bunch.
-Vineet