[merged mm-stable] alloc_tag-prevent-enabling-memory-profiling-if-it-was-shut-down.patch removed from -mm tree

[Andrew Morton <akpm@linux-foundation.org>]

The quilt patch titled
     Subject: alloc_tag: prevent enabling memory profiling if it was shut down
has been removed from the -mm tree.  Its filename was
     alloc_tag-prevent-enabling-memory-profiling-if-it-was-shut-down.patch

This patch was dropped because it was merged into the mm-stable branch
of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

------------------------------------------------------
From: Suren Baghdasaryan <surenb@google.com>
Subject: alloc_tag: prevent enabling memory profiling if it was shut down
Date: Mon, 15 Sep 2025 14:27:55 -0700

Memory profiling can be shut down due to reasons like a failure during
initialization.  When this happens, the user should not be able to
re-enable it.  Current sysctrl interface does not handle this properly and
will allow re-enabling memory profiling.  Fix this by checking for this
condition during sysctrl write operation.

Link: https://lkml.kernel.org/r/20250915212756.3998938-3-surenb@google.com
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Acked-by: Usama Arif <usamaarif642@gmail.com>
Cc: David Wang <00107082@163.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Sourav Panda <souravpanda@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 lib/alloc_tag.c |   16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)

--- a/lib/alloc_tag.c~alloc_tag-prevent-enabling-memory-profiling-if-it-was-shut-down
+++ a/lib/alloc_tag.c
@@ -766,6 +766,20 @@ struct page_ext_operations page_alloc_ta
 EXPORT_SYMBOL(page_alloc_tagging_ops);
 
 #ifdef CONFIG_SYSCTL
+/*
+ * Not using proc_do_static_key() directly to prevent enabling profiling
+ * after it was shut down.
+ */
+static int proc_mem_profiling_handler(const struct ctl_table *table, int write,
+				      void *buffer, size_t *lenp, loff_t *ppos)
+{
+	if (!mem_profiling_support && write)
+		return -EINVAL;
+
+	return proc_do_static_key(table, write, buffer, lenp, ppos);
+}
+
+
 static struct ctl_table memory_allocation_profiling_sysctls[] = {
 	{
 		.procname	= "mem_profiling",
@@ -775,7 +789,7 @@ static struct ctl_table memory_allocatio
 #else
 		.mode		= 0644,
 #endif
-		.proc_handler	= proc_do_static_key,
+		.proc_handler	= proc_mem_profiling_handler,
 	},
 };
 
_

Patches currently in -mm which might be from surenb@google.com are