diff mbox series

[2/2] signal: move show_unhandled_signals sysctl to its own file

Message ID 20230522210814.1919325-3-mcgrof@kernel.org
State New
Headers
Series kernel/sysctl.c: remove to major base directories |

Commit Message

Luis Chamberlain May 22, 2023, 9:08 p.m. UTC 
  The show_unhandled_signals sysctl is the only sysctl for debug
left on kernel/sysctl.c. We've been moving the syctls out from
kernel/sysctl.c so to help avoid merge conflicts as the shared
array gets out of hand.

This change incurs simplifies sysctl registration by localizing
it where it should go for a penalty in size of increasing the
kernel by 23 bytes, we accept this given recent cleanups have
actually already saved us 1465 bytes in the prior commits.

./scripts/bloat-o-meter vmlinux.3-remove-dev-table vmlinux.4-remove-debug-table
add/remove: 3/1 grow/shrink: 0/1 up/down: 177/-154 (23)
Function                                     old     new   delta
signal_debug_table                             -     128    +128
init_signal_sysctls                            -      33     +33
__pfx_init_signal_sysctls                      -      16     +16
sysctl_init_bases                             85      59     -26
debug_table                                  128       -    -128
Total: Before=21256967, After=21256990, chg +0.00%

Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
---
 arch/parisc/kernel/traps.c |  1 +
 arch/x86/kernel/signal.c   |  1 +
 arch/x86/kernel/traps.c    |  1 +
 arch/x86/kernel/umip.c     |  1 +
 arch/x86/mm/fault.c        |  1 +
 kernel/signal.c            | 23 +++++++++++++++++++++++
 kernel/sysctl.c            | 14 --------------
 7 files changed, 28 insertions(+), 14 deletions(-)

Comments

Dave Hansen May 23, 2023, 2:16 p.m. UTC | #1 
On 5/22/23 14:08, Luis Chamberlain wrote:
> --- a/arch/x86/kernel/umip.c
> +++ b/arch/x86/kernel/umip.c
> @@ -12,6 +12,7 @@
>  #include <asm/insn.h>
>  #include <asm/insn-eval.h>
>  #include <linux/ratelimit.h>
> +#include <linux/signal.h>

Oh, so this is actually fixing a bug: umip.c uses
'show_unhandled_signals' but it doesn't explicitly include
linux/signal.h where 'show_unhandled_signals' is declared.

It doesn't actually have anything to do with moving the
show_unhandled_signals sysctl, right?

If that's the case, it would be nice to have this in its own patch.
Luis Chamberlain May 24, 2023, 7:30 a.m. UTC | #2 
On Tue, May 23, 2023 at 07:16:55AM -0700, Dave Hansen wrote:
> On 5/22/23 14:08, Luis Chamberlain wrote:
> > --- a/arch/x86/kernel/umip.c
> > +++ b/arch/x86/kernel/umip.c
> > @@ -12,6 +12,7 @@
> >  #include <asm/insn.h>
> >  #include <asm/insn-eval.h>
> >  #include <linux/ratelimit.h>
> > +#include <linux/signal.h>
> 
> Oh, so this is actually fixing a bug: umip.c uses
> 'show_unhandled_signals' but it doesn't explicitly include
> linux/signal.h where 'show_unhandled_signals' is declared.

Fixes a non-critical bug perhaps, but I doubt it would be fixing
a functional bug as otherwise folks would have reported a build bug, no?

What or how it ends up including that file today to avoid build
failures is beyond me.

> It doesn't actually have anything to do with moving the
> show_unhandled_signals sysctl, right?

Well in my case it is making sure the sysctl variable used is declared
as well.

> If that's the case, it would be nice to have this in its own patch.

If its not really fixing any build bugs or functional bugs I don't see
the need. But if you really want it, I can do it.

Let me know!

  Luis
Luis Chamberlain May 25, 2023, 6:45 p.m. UTC | #3 
On Wed, May 24, 2023 at 12:30:37AM -0700, Luis Chamberlain wrote:
> Let me know!

Re-poke. I know, it's just been a day :P

  Luis
Dave Hansen May 25, 2023, 6:52 p.m. UTC | #4 
On 5/24/23 00:30, Luis Chamberlain wrote:
>> It doesn't actually have anything to do with moving the
>> show_unhandled_signals sysctl, right?
> Well in my case it is making sure the sysctl variable used is declared
> as well.

But what does this have to do with _this_ patch?  This:

> --- a/arch/x86/kernel/umip.c
> +++ b/arch/x86/kernel/umip.c
> @@ -12,6 +12,7 @@
>  #include <asm/insn.h>
>  #include <asm/insn-eval.h>
>  #include <linux/ratelimit.h>
> +#include <linux/signal.h>

For instance.  You don't move things to another header or make *ANY*
change to the compilation of umip.c.  So why patch it?

It looks to me like a _fundamentally_ superfluous change.  That hunk
literally *can't* be related to the rest of the patch.

>> If that's the case, it would be nice to have this in its own patch.
> If its not really fixing any build bugs or functional bugs I don't see
> the need. But if you really want it, I can do it.
> 
> Let me know!

Yes, I really want it.

Please remove all the x86 bits from _this_ patch.  If x86 has a
separate, preexisting problem, please send that patch separately with a
separate changelog and justification.

We'll take a look.
Luis Chamberlain May 25, 2023, 11:04 p.m. UTC | #5 
On Thu, May 25, 2023 at 11:52:58AM -0700, Dave Hansen wrote:
> On 5/24/23 00:30, Luis Chamberlain wrote:
> >> It doesn't actually have anything to do with moving the
> >> show_unhandled_signals sysctl, right?
> > Well in my case it is making sure the sysctl variable used is declared
> > as well.
> 
> But what does this have to do with _this_ patch?  This:

Because to create consistency for the users.

> > --- a/arch/x86/kernel/umip.c
> > +++ b/arch/x86/kernel/umip.c
> > @@ -12,6 +12,7 @@
> >  #include <asm/insn.h>
> >  #include <asm/insn-eval.h>
> >  #include <linux/ratelimit.h>
> > +#include <linux/signal.h>
> 
> For instance.  You don't move things to another header or make *ANY*
> change to the compilation of umip.c.  So why patch it?
> 
> It looks to me like a _fundamentally_ superfluous change.  That hunk
> literally *can't* be related to the rest of the patch.

I suspect it is not needed as otherwise compilation would have failed.
So I'll just drop it.

> >> If that's the case, it would be nice to have this in its own patch.
> > If its not really fixing any build bugs or functional bugs I don't see
> > the need. But if you really want it, I can do it.
> > 
> > Let me know!
> 
> Yes, I really want it.
> 
> Please remove all the x86 bits from _this_ patch.  If x86 has a
> separate, preexisting problem, please send that patch separately with a
> separate changelog and justification.
> 
> We'll take a look.

Sounds good.

  Luis
diff mbox series

Patch

diff --git a/arch/parisc/kernel/traps.c b/arch/parisc/kernel/traps.c
index f9696fbf646c..e15f7e201962 100644
--- a/arch/parisc/kernel/traps.c
+++ b/arch/parisc/kernel/traps.c
@@ -23,6 +23,7 @@ 
 #include <linux/module.h>
 #include <linux/smp.h>
 #include <linux/spinlock.h>
+#include <linux/signal.h>
 #include <linux/init.h>
 #include <linux/interrupt.h>
 #include <linux/console.h>
diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c
index 004cb30b7419..91905377d708 100644
--- a/arch/x86/kernel/signal.c
+++ b/arch/x86/kernel/signal.c
@@ -12,6 +12,7 @@ 
 
 #include <linux/sched.h>
 #include <linux/sched/task_stack.h>
+#include <linux/signal.h>
 #include <linux/mm.h>
 #include <linux/smp.h>
 #include <linux/kernel.h>
diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index 58b1f208eff5..180d770f8817 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -31,6 +31,7 @@ 
 #include <linux/kexec.h>
 #include <linux/sched.h>
 #include <linux/sched/task_stack.h>
+#include <linux/signal.h>
 #include <linux/timer.h>
 #include <linux/init.h>
 #include <linux/bug.h>
diff --git a/arch/x86/kernel/umip.c b/arch/x86/kernel/umip.c
index 5a4b21389b1d..cef5240dcd92 100644
--- a/arch/x86/kernel/umip.c
+++ b/arch/x86/kernel/umip.c
@@ -12,6 +12,7 @@ 
 #include <asm/insn.h>
 #include <asm/insn-eval.h>
 #include <linux/ratelimit.h>
+#include <linux/signal.h>
 
 #undef pr_fmt
 #define pr_fmt(fmt) "umip: " fmt
diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index e4399983c50c..e5f13250e68c 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -6,6 +6,7 @@ 
  */
 #include <linux/sched.h>		/* test_thread_flag(), ...	*/
 #include <linux/sched/task_stack.h>	/* task_stack_*(), ...		*/
+#include <linux/sched/signal.h>		/* show_unhandled_signals */
 #include <linux/kdebug.h>		/* oops_begin/end, ...		*/
 #include <linux/extable.h>		/* search_exception_tables	*/
 #include <linux/memblock.h>		/* max_low_pfn			*/
diff --git a/kernel/signal.c b/kernel/signal.c
index 8f6330f0e9ca..5ba4150c01a7 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -45,6 +45,7 @@ 
 #include <linux/posix-timers.h>
 #include <linux/cgroup.h>
 #include <linux/audit.h>
+#include <linux/sysctl.h>
 
 #define CREATE_TRACE_POINTS
 #include <trace/events/signal.h>
@@ -4771,6 +4772,28 @@  static inline void siginfo_buildtime_checks(void)
 #endif
 }
 
+#if defined(CONFIG_SYSCTL)
+static struct ctl_table signal_debug_table[] = {
+#ifdef CONFIG_SYSCTL_EXCEPTION_TRACE
+	{
+		.procname	= "exception-trace",
+		.data		= &show_unhandled_signals,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec
+	},
+#endif
+	{ }
+};
+
+static int __init init_signal_sysctls(void)
+{
+	register_sysctl_init("debug", signal_debug_table);
+	return 0;
+}
+early_initcall(init_signal_sysctls);
+#endif /* CONFIG_SYSCTL */
+
 void __init signals_init(void)
 {
 	siginfo_buildtime_checks();
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index a7fdb828afb6..43240955dcad 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -2331,24 +2331,10 @@  static struct ctl_table vm_table[] = {
 	{ }
 };
 
-static struct ctl_table debug_table[] = {
-#ifdef CONFIG_SYSCTL_EXCEPTION_TRACE
-	{
-		.procname	= "exception-trace",
-		.data		= &show_unhandled_signals,
-		.maxlen		= sizeof(int),
-		.mode		= 0644,
-		.proc_handler	= proc_dointvec
-	},
-#endif
-	{ }
-};
-
 int __init sysctl_init_bases(void)
 {
 	register_sysctl_init("kernel", kern_table);
 	register_sysctl_init("vm", vm_table);
-	register_sysctl_init("debug", debug_table);
 
 	return 0;
 }