Steven Rostedt (Google)
6a42eb0d21
tracing: Inform kmemleak of saved_cmdlines allocation ...
commit 2394ac4145ea91b92271e675a09af2a9ea6840b7 upstream.
The allocation of the struct saved_cmdlines_buffer structure changed from:
s = kmalloc(sizeof(*s), GFP_KERNEL);
s->saved_cmdlines = kmalloc_array(TASK_COMM_LEN, val, GFP_KERNEL);
to:
orig_size = sizeof(*s) + val * TASK_COMM_LEN;
order = get_order(orig_size);
size = 1 << (order + PAGE_SHIFT);
page = alloc_pages(GFP_KERNEL, order);
if (!page)
return NULL;
s = page_address(page);
memset(s, 0, sizeof(*s));
s->saved_cmdlines = kmalloc_array(TASK_COMM_LEN, val, GFP_KERNEL);
Where that s->saved_cmdlines allocation looks to be a dangling allocation
to kmemleak. That's because kmemleak only keeps track of kmalloc()
allocations. For allocations that use page_alloc() directly, the kmemleak
needs to be explicitly informed about it.
Add kmemleak_alloc() and kmemleak_free() around the page allocation so
that it doesn't give the following false positive:
unreferenced object 0xffff8881010c8000 (size 32760):
comm "swapper", pid 0, jiffies 4294667296
hex dump (first 32 bytes):
ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ................
ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ................
backtrace (crc ae6ec1b9):
[<ffffffff86722405>] kmemleak_alloc+0x45/0x80
[<ffffffff8414028d>] __kmalloc_large_node+0x10d/0x190
[<ffffffff84146ab1>] __kmalloc+0x3b1/0x4c0
[<ffffffff83ed7103>] allocate_cmdlines_buffer+0x113/0x230
[<ffffffff88649c34>] tracer_alloc_buffers.isra.0+0x124/0x460
[<ffffffff8864a174>] early_trace_init+0x14/0xa0
[<ffffffff885dd5ae>] start_kernel+0x12e/0x3c0
[<ffffffff885f5758>] x86_64_start_reservations+0x18/0x30
[<ffffffff885f582b>] x86_64_start_kernel+0x7b/0x80
[<ffffffff83a001c3>] secondary_startup_64_no_verify+0x15e/0x16b
Link: https://lore.kernel.org/linux-trace-kernel/87r0hfnr9r.fsf@kernel.org/
Link: https://lore.kernel.org/linux-trace-kernel/20240214112046.09a322d6@gandalf.local.home
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Fixes: 44dc5c41b5b1 ("tracing: Fix wasted memory in saved_cmdlines logic")
Reported-by: Kalle Valo <kvalo@kernel.org>
Tested-by: Kalle Valo <kvalo@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-02-23 08:42:30 +01:00
2023-01-14 10:15:41 +01:00
2023-09-19 12:20:07 +02:00
2021-02-10 09:29:16 +01:00
2023-07-27 08:44:44 +02:00
2021-01-19 18:27:19 +01:00
2023-04-05 11:23:46 +02:00
2024-02-23 08:42:27 +01:00
2024-01-05 15:12:28 +01:00
2021-09-22 12:28:03 +02:00
2021-06-23 14:42:50 +02:00
2022-12-08 11:23:58 +01:00
2023-11-28 16:55:02 +00:00
2023-07-27 08:44:43 +02:00
2023-10-10 21:53:25 +02:00
2023-06-28 10:28:06 +02:00
2024-02-23 08:42:24 +01:00
2023-11-28 16:55:02 +00:00
2020-10-25 14:51:49 -07:00
2021-10-27 09:56:56 +02:00
2020-11-30 21:43:07 -05:00
2023-08-30 16:23:12 +02:00
2023-11-20 11:06:57 +01:00
2024-01-25 14:37:37 -08:00
2022-09-23 14:16:58 +02:00
2020-10-15 15:51:28 -07:00
2023-08-26 15:26:50 +02:00
2022-08-25 11:38:23 +02:00
2023-06-09 10:30:16 +02:00
2023-08-30 16:23:12 +02:00
2020-12-30 11:54:28 +01:00
2021-07-28 14:35:45 +02:00
2023-09-19 12:20:07 +02:00
2024-02-23 08:42:30 +01:00
2023-11-28 16:55:02 +00:00
2024-02-23 08:41:56 +01:00
6a42eb0d21