Messages in this thread | | | Date | Wed, 15 Dec 2021 21:33:14 +0800 | Subject | Re: [PATCH] optee: Suppress false positive kmemleak report in optee_handle_rpc() | From | "Wang, Xiaolei" <> |
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在 12/15/2021 8:29 PM, Jens Wiklander 写道: > [Please note: This e-mail is from an EXTERNAL e-mail address] > > On Mon, Dec 06, 2021 at 08:05:33PM +0800, Xiaolei Wang wrote: >> We observed the following kmemleak report: >> unreferenced object 0xffff000007904500 (size 128): >> comm "swapper/0", pid 1, jiffies 4294892671 (age 44.036s) >> hex dump (first 32 bytes): >> 00 47 90 07 00 00 ff ff 60 00 c0 ff 00 00 00 00 .G......`....... >> 60 00 80 13 00 80 ff ff a0 00 00 00 00 00 00 00 `............... >> backtrace: >> [<000000004c12b1c7>] kmem_cache_alloc+0x1ac/0x2f4 >> [<000000005d23eb4f>] tee_shm_alloc+0x78/0x230 >> [<00000000794dd22c>] optee_handle_rpc+0x60/0x6f0 >> [<00000000d9f7c52d>] optee_do_call_with_arg+0x17c/0x1dc >> [<00000000c35884da>] optee_open_session+0x128/0x1ec >> [<000000001748f2ff>] tee_client_open_session+0x28/0x40 >> [<00000000aecb5389>] optee_enumerate_devices+0x84/0x2a0 >> [<000000003df18bf1>] optee_probe+0x674/0x6cc >> [<000000003a4a534a>] platform_drv_probe+0x54/0xb0 >> [<000000000c51ce7d>] really_probe+0xe4/0x4d0 >> [<000000002f04c865>] driver_probe_device+0x58/0xc0 >> [<00000000b485397d>] device_driver_attach+0xc0/0xd0 >> [<00000000c835f0df>] __driver_attach+0x84/0x124 >> [<000000008e5a429c>] bus_for_each_dev+0x70/0xc0 >> [<000000001735e8a8>] driver_attach+0x24/0x30 >> [<000000006d94b04f>] bus_add_driver+0x104/0x1ec >> >> This is not a memory leak because we pass the share memory pointer >> to secure world and would get it from secure world before releasing it. >> >> Signed-off-by: Xiaolei Wang <xiaolei.wang@windriver.com> >> --- >> drivers/tee/optee/smc_abi.c | 2 ++ >> 1 file changed, 2 insertions(+) >> >> diff --git a/drivers/tee/optee/smc_abi.c b/drivers/tee/optee/smc_abi.c >> index 6196d7c3888f..cf2e3293567d 100644 >> --- a/drivers/tee/optee/smc_abi.c >> +++ b/drivers/tee/optee/smc_abi.c >> @@ -23,6 +23,7 @@ >> #include "optee_private.h" >> #include "optee_smc.h" >> #include "optee_rpc_cmd.h" >> +#include <linux/kmemleak.h> >> #define CREATE_TRACE_POINTS >> #include "optee_trace.h" >> >> @@ -783,6 +784,7 @@ static void optee_handle_rpc(struct tee_context *ctx, >> param->a4 = 0; >> param->a5 = 0; >> } >> + kmemleak_not_leak(shm); > Eventually this pointer will be freed below with the call to tee_shm_free(). > I assume than once the memory is freed it's not execused from being a leak > any longer. Is that correct?
Yes, it is the correct way to release memory through tee_shm_free, but if a memory leak is detected by the kernel before free memory, it is obviously a false alarm.
thanks
xiaolei
> > Thanks, > Jens > >> break; >> case OPTEE_SMC_RPC_FUNC_FREE: >> shm = reg_pair_to_ptr(param->a1, param->a2); >> -- >> 2.25.1 >>
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