Subject: linux-next: manual merge of the sysctl tree with the mm-nonmm-unstable tree

From: Stephen Rothwell <[email-masked]>
Date: Tue, 8 Jul 2025 19:00:03 +1000

Hi all,

Today's linux-next merge of the sysctl tree got a conflict in:

  kernel/panic.c

between commits:

  f8dbd6138e05 ("panic: add 'panic_sys_info' sysctl to take human readable string parameter")
  3699d83ae18b ("panic: add note that panic_print sysctl interface is deprecated")

from the mm-nonmm-unstable tree and commits:

  48f1dc94d25e ("sysctl: Move tainted ctl_table into kernel/panic.c")
  9aa4e27ef60c ("sysctl: Move sysctl_panic_on_stackoverflow to kernel/panic.c")

from the sysctl tree.

I fixed it up (see below) and can carry the fix as necessary. This
is now fixed as far as linux-next is concerned, but any non trivial
conflicts should be mentioned to your upstream maintainer when your tree
is submitted for merging.  You may also want to consider cooperating
with the maintainer of the conflicting tree to minimise any particularly
complex conflicts.

-- 
Cheers,
Stephen Rothwell

diff --cc kernel/panic.c
index df92b763f857,64e58835086d..000000000000
--- a/kernel/panic.c
+++ b/kernel/panic.c
@@@ -78,13 -84,50 +78,56 @@@ ATOMIC_NOTIFIER_HEAD(panic_notifier_lis
  EXPORT_SYMBOL(panic_notifier_list);
  
  #ifdef CONFIG_SYSCTL
 +static int sysctl_panic_print_handler(const struct ctl_table *table, int write,
 +			   void *buffer, size_t *lenp, loff_t *ppos)
 +{
 +	pr_info_once("Kernel: 'panic_print' sysctl interface will be obsoleted by both 'panic_sys_info' and 'panic_console_replay'\n");
 +	return proc_doulongvec_minmax(table, write, buffer, lenp, ppos);
 +}
  
+ /*
+  * Taint values can only be increased
+  * This means we can safely use a temporary.
+  */
+ static int proc_taint(const struct ctl_table *table, int write,
+ 			       void *buffer, size_t *lenp, loff_t *ppos)
+ {
+ 	struct ctl_table t;
+ 	unsigned long tmptaint = get_taint();
+ 	int err;
+ 
+ 	if (write && !capable(CAP_SYS_ADMIN))
+ 		return -EPERM;
+ 
+ 	t = *table;
+ 	t.data = &tmptaint;
+ 	err = proc_doulongvec_minmax(&t, write, buffer, lenp, ppos);
+ 	if (err < 0)
+ 		return err;
+ 
+ 	if (write) {
+ 		int i;
+ 
+ 		/*
+ 		 * If we are relying on panic_on_taint not producing
+ 		 * false positives due to userspace input, bail out
+ 		 * before setting the requested taint flags.
+ 		 */
+ 		if (panic_on_taint_nousertaint && (tmptaint & panic_on_taint))
+ 			return -EINVAL;
+ 
+ 		/*
+ 		 * Poor man's atomic or. Not worth adding a primitive
+ 		 * to everyone's atomic.h for this
+ 		 */
+ 		for (i = 0; i < TAINT_FLAGS_COUNT; i++)
+ 			if ((1UL << i) & tmptaint)
+ 				add_taint(i, LOCKDEP_STILL_OK);
+ 	}
+ 
+ 	return err;
+ }
+ 
  static const struct ctl_table kern_panic_table[] = {
  #ifdef CONFIG_SMP
  	{
@@@ -134,13 -183,16 +183,23 @@@
  		.mode           = 0644,
  		.proc_handler   = proc_douintvec,
  	},
 +	{
 +		.procname	= "panic_sys_info",
 +		.data		= &panic_print,
 +		.maxlen         = sizeof(panic_print),
 +		.mode		= 0644,
 +		.proc_handler	= sysctl_sys_info_handler,
 +	},
+ #if (defined(CONFIG_X86_32) || defined(CONFIG_PARISC)) && \
+ 	defined(CONFIG_DEBUG_STACKOVERFLOW)
+ 	{
+ 		.procname	= "panic_on_stackoverflow",
+ 		.data		= &sysctl_panic_on_stackoverflow,
+ 		.maxlen		= sizeof(int),
+ 		.mode		= 0644,
+ 		.proc_handler	= proc_dointvec,
+ 	},
+ #endif
  };
  
  static __init int kernel_panic_sysctls_init(void)