[PATCH v2 2/2] signal: move show_unhandled_signals sysctl to its own file

From: Luis Chamberlain
Date: Fri May 26 2023 - 18:22:51 EST


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@xxxxxxxxxx>
---
kernel/signal.c | 23 +++++++++++++++++++++++
kernel/sysctl.c | 14 --------------
2 files changed, 23 insertions(+), 14 deletions(-)

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;
}
--
2.39.2