[PATCH v2] perf ftrace: Fix hashmap__new() error checking

[PATCH v2] perf ftrace: Fix hashmap__new() error checking

[Chen Ni]

The hashmap__new() function never returns NULL, it returns error
pointers. Fix the error checking to match.

Additionally, set ftrace->profile_hash to NULL on error, and return the
exact error code from hashmap__new().

Fixes: 0f223813edd0 ("perf ftrace: Add 'profile' command")
Suggested-by: Ian Rogers <irogers@google.com>
Signed-off-by: Chen Ni <nichen@iscas.ac.cn>
---
Changes in v2:
- Set ftrace->profile_hash to NULL on error
- Return PTR_ERR(ftrace->profile_hash) instead of -ENOMEM
- Update commit message
---
 tools/perf/builtin-ftrace.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/tools/perf/builtin-ftrace.c b/tools/perf/builtin-ftrace.c
index 6b6eec65f93f..4cc33452d79b 100644
--- a/tools/perf/builtin-ftrace.c
+++ b/tools/perf/builtin-ftrace.c
@@ -18,6 +18,7 @@
 #include <poll.h>
 #include <ctype.h>
 #include <linux/capability.h>
+#include <linux/err.h>
 #include <linux/string.h>
 #include <sys/stat.h>
 
@@ -1209,8 +1210,12 @@ static int prepare_func_profile(struct perf_ftrace *ftrace)
 	ftrace->graph_verbose = 0;
 
 	ftrace->profile_hash = hashmap__new(profile_hash, profile_equal, NULL);
-	if (ftrace->profile_hash == NULL)
-		return -ENOMEM;
+	if (IS_ERR(ftrace->profile_hash)) {
+		int err = PTR_ERR(ftrace->profile_hash);
+
+		ftrace->profile_hash = NULL;
+		return err;
+	}
 
 	return 0;
 }
-- 
2.25.1

Re: [PATCH v2] perf ftrace: Fix hashmap__new() error checking

[Arnaldo Carvalho de Melo]

On Fri, Mar 06, 2026 at 12:10:52PM +0800, Chen Ni wrote:
> The hashmap__new() function never returns NULL, it returns error
> pointers. Fix the error checking to match.
> 
> Additionally, set ftrace->profile_hash to NULL on error, and return the
> exact error code from hashmap__new().

Thanks, applied to perf-tools, for v7.0.

- Arnaldo
 
> Fixes: 0f223813edd0 ("perf ftrace: Add 'profile' command")
> Suggested-by: Ian Rogers <irogers@google.com>
> Signed-off-by: Chen Ni <nichen@iscas.ac.cn>
> ---
> Changes in v2:
> - Set ftrace->profile_hash to NULL on error
> - Return PTR_ERR(ftrace->profile_hash) instead of -ENOMEM
> - Update commit message
> ---
>  tools/perf/builtin-ftrace.c | 9 +++++++--
>  1 file changed, 7 insertions(+), 2 deletions(-)
> 
> diff --git a/tools/perf/builtin-ftrace.c b/tools/perf/builtin-ftrace.c
> index 6b6eec65f93f..4cc33452d79b 100644
> --- a/tools/perf/builtin-ftrace.c
> +++ b/tools/perf/builtin-ftrace.c
> @@ -18,6 +18,7 @@
>  #include <poll.h>
>  #include <ctype.h>
>  #include <linux/capability.h>
> +#include <linux/err.h>
>  #include <linux/string.h>
>  #include <sys/stat.h>
>  
> @@ -1209,8 +1210,12 @@ static int prepare_func_profile(struct perf_ftrace *ftrace)
>  	ftrace->graph_verbose = 0;
>  
>  	ftrace->profile_hash = hashmap__new(profile_hash, profile_equal, NULL);
> -	if (ftrace->profile_hash == NULL)
> -		return -ENOMEM;
> +	if (IS_ERR(ftrace->profile_hash)) {
> +		int err = PTR_ERR(ftrace->profile_hash);
> +
> +		ftrace->profile_hash = NULL;
> +		return err;
> +	}
>  
>  	return 0;
>  }
> -- 
> 2.25.1