From 9d832f5acc7ff74e4f39398f2f82b740eb48d762 Mon Sep 17 00:00:00 2001
From: Ivan Volosyuk <Ivan.Volosyuk@gmail.com>
Date: Mon, 25 Nov 2024 23:33:58 +1100
Subject: [PATCH] Linux: Guard proc sentinel values using kernel version.

Kernel 6.11-rc1 and later no longer use proc sentinels and zfs module
will fail loading if compiled with CONFIG_RANDSTRUCT_PERFORMANCE=y

The change restricts use of the sentinel values to earlier kernel
versions. Ideally we should check for sentinels instead of kernel
version.

Closes #16620
Signed-off-by: Ivan Volosyuk <Ivan.Volosyuk@gmail.com>
---
 module/os/linux/spl/spl-proc.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/module/os/linux/spl/spl-proc.c b/module/os/linux/spl/spl-proc.c
index 9af192274733..1f745b5dc35a 100644
--- a/module/os/linux/spl/spl-proc.c
+++ b/module/os/linux/spl/spl-proc.c
@@ -51,6 +51,10 @@ typedef struct ctl_table spl_ctl_table;
 #define	CONST_CTL_TABLE		struct ctl_table
 #endif
 
+#if LINUX_VERSION_CODE < KERNEL_VERSION(6, 11, 0)
+#define PROC_USE_SENTINELS
+#endif
+
 static unsigned long table_min = 0;
 static unsigned long table_max = ~0;
 
@@ -359,11 +363,15 @@ static struct ctl_table spl_kmem_table[] = {
 		.mode		= 0444,
 		.proc_handler	= &proc_doslab,
 	},
+#ifdef PROC_USE_SENTINELS
 	{},
+#endif
 };
 
 static struct ctl_table spl_kstat_table[] = {
+#ifdef PROC_USE_SENTINELS
 	{},
+#endif
 };
 
 static struct ctl_table spl_table[] = {
@@ -397,7 +405,9 @@ static struct ctl_table spl_table[] = {
 		.child		= spl_kstat_table,
 	},
 #endif
+#ifdef PROC_USE_SENTINELS
 	{},
+#endif
 };
 
 #ifdef HAVE_REGISTER_SYSCTL_TABLE
@@ -407,7 +417,9 @@ static struct ctl_table spl_dir[] = {
 		.mode		= 0555,
 		.child		= spl_table,
 	},
+#ifdef PROC_USE_SENTINELS
 	{}
+#endif
 };
 
 static struct ctl_table spl_root[] = {
@@ -416,7 +428,9 @@ static struct ctl_table spl_root[] = {
 		.mode		= 0555,
 		.child		= spl_dir,
 	},
+#ifdef PROC_USE_SENTINELS
 	{}
+#endif
 };
 #endif