diff options
| author | Suren Baghdasaryan <surenb@google.com> | 2025-09-15 14:27:55 -0700 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2025-09-21 14:22:30 -0700 |
| commit | 9e8a0bbb128ec9379ce271ccecdfb022c483da0b (patch) | |
| tree | c9a6c25ebc482e608b3571f631f394d44245a029 /lib | |
| parent | 123bcf284205b2513c4172c50da8d193f8f8ab3d (diff) | |
alloc_tag: prevent enabling memory profiling if it was shut down
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>
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/alloc_tag.c | 16 |
1 files changed, 15 insertions, 1 deletions
diff --git a/lib/alloc_tag.c b/lib/alloc_tag.c index 715315f5d9ba..f79217427d81 100644 --- a/lib/alloc_tag.c +++ b/lib/alloc_tag.c @@ -766,6 +766,20 @@ struct page_ext_operations page_alloc_tagging_ops = { 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_allocation_profiling_sysctls[] = { #else .mode = 0644, #endif - .proc_handler = proc_do_static_key, + .proc_handler = proc_mem_profiling_handler, }, }; |