[PATCH 3/3] perf bpf: Fix two memory leakages when calling perf_env__insert_bpf_prog_info()

Zhongqiu Han posted 3 patches 1 year, 2 months ago
There is a newer version of this series
[PATCH 3/3] perf bpf: Fix two memory leakages when calling perf_env__insert_bpf_prog_info()
Posted by Zhongqiu Han 1 year, 2 months ago
If perf_env__insert_bpf_prog_info() returns false due to a duplicate bpf
prog info node insertion, the temporary info_node and info_linear memory
will leak. Add a check to ensure the memory is freed if the function
returns false.

Fixes: 9c51f8788b5d ("perf env: Avoid recursively taking env->bpf_progs.lock")
Signed-off-by: Zhongqiu Han <quic_zhonhan@quicinc.com>
---
 tools/perf/util/bpf-event.c | 10 ++++++++--
 tools/perf/util/env.c       |  7 +++++--
 tools/perf/util/env.h       |  2 +-
 3 files changed, 14 insertions(+), 5 deletions(-)

diff --git a/tools/perf/util/bpf-event.c b/tools/perf/util/bpf-event.c
index 13608237c50e..c81444059ad0 100644
--- a/tools/perf/util/bpf-event.c
+++ b/tools/perf/util/bpf-event.c
@@ -289,7 +289,10 @@ static int perf_event__synthesize_one_bpf_prog(struct perf_session *session,
 		}
 
 		info_node->info_linear = info_linear;
-		perf_env__insert_bpf_prog_info(env, info_node);
+		if (!perf_env__insert_bpf_prog_info(env, info_node)) {
+			free(info_linear);
+			free(info_node);
+		}
 		info_linear = NULL;
 
 		/*
@@ -480,7 +483,10 @@ static void perf_env__add_bpf_info(struct perf_env *env, u32 id)
 	info_node = malloc(sizeof(struct bpf_prog_info_node));
 	if (info_node) {
 		info_node->info_linear = info_linear;
-		perf_env__insert_bpf_prog_info(env, info_node);
+		if (!perf_env__insert_bpf_prog_info(env, info_node)) {
+			free(info_linear);
+			free(info_node);
+		}
 	} else
 		free(info_linear);
 
diff --git a/tools/perf/util/env.c b/tools/perf/util/env.c
index d7865ae5f8f5..38401a289c24 100644
--- a/tools/perf/util/env.c
+++ b/tools/perf/util/env.c
@@ -24,12 +24,15 @@ struct perf_env perf_env;
 #include "bpf-utils.h"
 #include <bpf/libbpf.h>
 
-void perf_env__insert_bpf_prog_info(struct perf_env *env,
+bool perf_env__insert_bpf_prog_info(struct perf_env *env,
 				    struct bpf_prog_info_node *info_node)
 {
+	bool ret = true;
 	down_write(&env->bpf_progs.lock);
-	__perf_env__insert_bpf_prog_info(env, info_node);
+	if (!__perf_env__insert_bpf_prog_info(env, info_node))
+		ret = false;
 	up_write(&env->bpf_progs.lock);
+	return ret;
 }
 
 bool __perf_env__insert_bpf_prog_info(struct perf_env *env, struct bpf_prog_info_node *info_node)
diff --git a/tools/perf/util/env.h b/tools/perf/util/env.h
index 9db2e5a625ed..da11add761d0 100644
--- a/tools/perf/util/env.h
+++ b/tools/perf/util/env.h
@@ -178,7 +178,7 @@ int perf_env__nr_cpus_avail(struct perf_env *env);
 void perf_env__init(struct perf_env *env);
 bool __perf_env__insert_bpf_prog_info(struct perf_env *env,
 				      struct bpf_prog_info_node *info_node);
-void perf_env__insert_bpf_prog_info(struct perf_env *env,
+bool perf_env__insert_bpf_prog_info(struct perf_env *env,
 				    struct bpf_prog_info_node *info_node);
 struct bpf_prog_info_node *perf_env__find_bpf_prog_info(struct perf_env *env,
 							__u32 prog_id);
-- 
2.25.1
Re: [PATCH 3/3] perf bpf: Fix two memory leakages when calling perf_env__insert_bpf_prog_info()
Posted by Namhyung Kim 1 year, 2 months ago
Hello,

On Thu, Nov 28, 2024 at 08:54:32PM +0800, Zhongqiu Han wrote:
> If perf_env__insert_bpf_prog_info() returns false due to a duplicate bpf
> prog info node insertion, the temporary info_node and info_linear memory
> will leak. Add a check to ensure the memory is freed if the function
> returns false.
> 
> Fixes: 9c51f8788b5d ("perf env: Avoid recursively taking env->bpf_progs.lock")
> Signed-off-by: Zhongqiu Han <quic_zhonhan@quicinc.com>
> ---
>  tools/perf/util/bpf-event.c | 10 ++++++++--
>  tools/perf/util/env.c       |  7 +++++--
>  tools/perf/util/env.h       |  2 +-
>  3 files changed, 14 insertions(+), 5 deletions(-)
> 
> diff --git a/tools/perf/util/bpf-event.c b/tools/perf/util/bpf-event.c
> index 13608237c50e..c81444059ad0 100644
> --- a/tools/perf/util/bpf-event.c
> +++ b/tools/perf/util/bpf-event.c
> @@ -289,7 +289,10 @@ static int perf_event__synthesize_one_bpf_prog(struct perf_session *session,
>  		}
>  
>  		info_node->info_linear = info_linear;
> -		perf_env__insert_bpf_prog_info(env, info_node);
> +		if (!perf_env__insert_bpf_prog_info(env, info_node)) {
> +			free(info_linear);
> +			free(info_node);
> +		}
>  		info_linear = NULL;
>  
>  		/*
> @@ -480,7 +483,10 @@ static void perf_env__add_bpf_info(struct perf_env *env, u32 id)
>  	info_node = malloc(sizeof(struct bpf_prog_info_node));
>  	if (info_node) {
>  		info_node->info_linear = info_linear;
> -		perf_env__insert_bpf_prog_info(env, info_node);
> +		if (!perf_env__insert_bpf_prog_info(env, info_node)) {
> +			free(info_linear);
> +			free(info_node);
> +		}
>  	} else
>  		free(info_linear);
>  
> diff --git a/tools/perf/util/env.c b/tools/perf/util/env.c
> index d7865ae5f8f5..38401a289c24 100644
> --- a/tools/perf/util/env.c
> +++ b/tools/perf/util/env.c
> @@ -24,12 +24,15 @@ struct perf_env perf_env;
>  #include "bpf-utils.h"
>  #include <bpf/libbpf.h>
>  
> -void perf_env__insert_bpf_prog_info(struct perf_env *env,
> +bool perf_env__insert_bpf_prog_info(struct perf_env *env,
>  				    struct bpf_prog_info_node *info_node)
>  {
> +	bool ret = true;

Please add a blank line between declaration and the other statements.
Also I think you can just use the return value of the internal function
instead of initializaing it to true.

Thanks,
Namhyung


>  	down_write(&env->bpf_progs.lock);
> -	__perf_env__insert_bpf_prog_info(env, info_node);
> +	if (!__perf_env__insert_bpf_prog_info(env, info_node))
> +		ret = false;
>  	up_write(&env->bpf_progs.lock);
> +	return ret;
>  }
>  
>  bool __perf_env__insert_bpf_prog_info(struct perf_env *env, struct bpf_prog_info_node *info_node)
> diff --git a/tools/perf/util/env.h b/tools/perf/util/env.h
> index 9db2e5a625ed..da11add761d0 100644
> --- a/tools/perf/util/env.h
> +++ b/tools/perf/util/env.h
> @@ -178,7 +178,7 @@ int perf_env__nr_cpus_avail(struct perf_env *env);
>  void perf_env__init(struct perf_env *env);
>  bool __perf_env__insert_bpf_prog_info(struct perf_env *env,
>  				      struct bpf_prog_info_node *info_node);
> -void perf_env__insert_bpf_prog_info(struct perf_env *env,
> +bool perf_env__insert_bpf_prog_info(struct perf_env *env,
>  				    struct bpf_prog_info_node *info_node);
>  struct bpf_prog_info_node *perf_env__find_bpf_prog_info(struct perf_env *env,
>  							__u32 prog_id);
> -- 
> 2.25.1
>
Re: [PATCH 3/3] perf bpf: Fix two memory leakages when calling perf_env__insert_bpf_prog_info()
Posted by Zhongqiu Han 1 year, 2 months ago
On 12/3/2024 6:02 AM, Namhyung Kim wrote:
> Hello,
> 
> On Thu, Nov 28, 2024 at 08:54:32PM +0800, Zhongqiu Han wrote:
>> If perf_env__insert_bpf_prog_info() returns false due to a duplicate bpf
>> prog info node insertion, the temporary info_node and info_linear memory
>> will leak. Add a check to ensure the memory is freed if the function
>> returns false.
>>
>> Fixes: 9c51f8788b5d ("perf env: Avoid recursively taking env->bpf_progs.lock")
>> Signed-off-by: Zhongqiu Han <quic_zhonhan@quicinc.com>
>> ---
>>   tools/perf/util/bpf-event.c | 10 ++++++++--
>>   tools/perf/util/env.c       |  7 +++++--
>>   tools/perf/util/env.h       |  2 +-
>>   3 files changed, 14 insertions(+), 5 deletions(-)
>>
>> diff --git a/tools/perf/util/bpf-event.c b/tools/perf/util/bpf-event.c
>> index 13608237c50e..c81444059ad0 100644
>> --- a/tools/perf/util/bpf-event.c
>> +++ b/tools/perf/util/bpf-event.c
>> @@ -289,7 +289,10 @@ static int perf_event__synthesize_one_bpf_prog(struct perf_session *session,
>>   		}
>>   
>>   		info_node->info_linear = info_linear;
>> -		perf_env__insert_bpf_prog_info(env, info_node);
>> +		if (!perf_env__insert_bpf_prog_info(env, info_node)) {
>> +			free(info_linear);
>> +			free(info_node);
>> +		}
>>   		info_linear = NULL;
>>   
>>   		/*
>> @@ -480,7 +483,10 @@ static void perf_env__add_bpf_info(struct perf_env *env, u32 id)
>>   	info_node = malloc(sizeof(struct bpf_prog_info_node));
>>   	if (info_node) {
>>   		info_node->info_linear = info_linear;
>> -		perf_env__insert_bpf_prog_info(env, info_node);
>> +		if (!perf_env__insert_bpf_prog_info(env, info_node)) {
>> +			free(info_linear);
>> +			free(info_node);
>> +		}
>>   	} else
>>   		free(info_linear);
>>   
>> diff --git a/tools/perf/util/env.c b/tools/perf/util/env.c
>> index d7865ae5f8f5..38401a289c24 100644
>> --- a/tools/perf/util/env.c
>> +++ b/tools/perf/util/env.c
>> @@ -24,12 +24,15 @@ struct perf_env perf_env;
>>   #include "bpf-utils.h"
>>   #include <bpf/libbpf.h>
>>   
>> -void perf_env__insert_bpf_prog_info(struct perf_env *env,
>> +bool perf_env__insert_bpf_prog_info(struct perf_env *env,
>>   				    struct bpf_prog_info_node *info_node)
>>   {
>> +	bool ret = true;
> 
> Please add a blank line between declaration and the other statements.
> Also I think you can just use the return value of the internal function
> instead of initializaing it to true.
> 
> Thanks,
> Namhyung
> 
> 

Hi Namhyung,
Thanks for your review~

I will add a blank line between the declaration and the other
statements, and optimize it as below:


+bool perf_env__insert_bpf_prog_info(struct perf_env *env,
  				    struct bpf_prog_info_node
*info_node)
  {
+	bool ret;
+
  	down_write(&env->bpf_progs.lock);
-	__perf_env__insert_bpf_prog_info(env, info_node);
+	ret = __perf_env__insert_bpf_prog_info(env, info_node);
  	up_write(&env->bpf_progs.lock);
+	return ret;
  }


>>   	down_write(&env->bpf_progs.lock);
>> -	__perf_env__insert_bpf_prog_info(env, info_node);
>> +	if (!__perf_env__insert_bpf_prog_info(env, info_node))
>> +		ret = false;
>>   	up_write(&env->bpf_progs.lock);
>> +	return ret;
>>   }
>>   
>>   bool __perf_env__insert_bpf_prog_info(struct perf_env *env, struct bpf_prog_info_node *info_node)
>> diff --git a/tools/perf/util/env.h b/tools/perf/util/env.h
>> index 9db2e5a625ed..da11add761d0 100644
>> --- a/tools/perf/util/env.h
>> +++ b/tools/perf/util/env.h
>> @@ -178,7 +178,7 @@ int perf_env__nr_cpus_avail(struct perf_env *env);
>>   void perf_env__init(struct perf_env *env);
>>   bool __perf_env__insert_bpf_prog_info(struct perf_env *env,
>>   				      struct bpf_prog_info_node *info_node);
>> -void perf_env__insert_bpf_prog_info(struct perf_env *env,
>> +bool perf_env__insert_bpf_prog_info(struct perf_env *env,
>>   				    struct bpf_prog_info_node *info_node);
>>   struct bpf_prog_info_node *perf_env__find_bpf_prog_info(struct perf_env *env,
>>   							__u32 prog_id);
>> -- 
>> 2.25.1
>>


-- 
Thx and BRs,
Zhongqiu Han