The hashmap__new() function does not return NULL on errors. It returns
ERR_PTR(-ENOMEM). Using IS_ERR() to check the return value
to fix this.
Signed-off-by: Miaoqian Lin <[email protected]>
---
tools/perf/util/stat.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/tools/perf/util/stat.c b/tools/perf/util/stat.c
index 09ea334586f2..a77052680087 100644
--- a/tools/perf/util/stat.c
+++ b/tools/perf/util/stat.c
@@ -311,8 +311,8 @@ static int check_per_pkg(struct evsel *counter,
if (!mask) {
mask = hashmap__new(pkg_id_hash, pkg_id_equal, NULL);
- if (!mask)
- return -ENOMEM;
+ if (IS_ERR(mask))
+ return PTR_ERR(mask);
counter->per_pkg_mask = mask;
}
--
2.17.1
Hi Miaoqian,
On 12/12/2021 04:23, Miaoqian Lin wrote:
> The hashmap__new() function does not return NULL on errors. It returns
> ERR_PTR(-ENOMEM). Using IS_ERR() to check the return value
> to fix this.
>
> Signed-off-by: Miaoqian Lin <[email protected]>
> ---
> tools/perf/util/stat.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/tools/perf/util/stat.c b/tools/perf/util/stat.c
> index 09ea334586f2..a77052680087 100644
> --- a/tools/perf/util/stat.c
> +++ b/tools/perf/util/stat.c
> @@ -311,8 +311,8 @@ static int check_per_pkg(struct evsel *counter,
>
> if (!mask) {
> mask = hashmap__new(pkg_id_hash, pkg_id_equal, NULL);
> - if (!mask)
> - return -ENOMEM;
> + if (IS_ERR(mask))
> + return PTR_ERR(mask);
I see that callers to "ids__new" are also missing these checks. Did you
consider patching those also?
Thanks,
German
>
> counter->per_pkg_mask = mask;
> }
On 12/12/2021 14:55, German Gomez wrote:
> Hi Miaoqian,
>
> On 12/12/2021 04:23, Miaoqian Lin wrote:
>> The hashmap__new() function does not return NULL on errors. It returns
>> ERR_PTR(-ENOMEM). Using IS_ERR() to check the return value
>> to fix this.
>>
>> Signed-off-by: Miaoqian Lin <[email protected]>
>> ---
>> tools/perf/util/stat.c | 4 ++--
>> 1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/tools/perf/util/stat.c b/tools/perf/util/stat.c
>> index 09ea334586f2..a77052680087 100644
>> --- a/tools/perf/util/stat.c
>> +++ b/tools/perf/util/stat.c
>> @@ -311,8 +311,8 @@ static int check_per_pkg(struct evsel *counter,
>>
>> if (!mask) {
>> mask = hashmap__new(pkg_id_hash, pkg_id_equal, NULL);
>> - if (!mask)
>> - return -ENOMEM;
>> + if (IS_ERR(mask))
>> + return PTR_ERR(mask);
Also (sorry, I haven't tried/tested the patch yet) is this return
necessary? To me it seems it's still ok to keep the "return -ENOMEM".
> I see that callers to "ids__new" are also missing these checks. Did you
> consider patching those also?
>
> Thanks,
> German
>
>>
>> counter->per_pkg_mask = mask;
>> }
callers of ids__new() function only do NULL checking for the return
value. ids__new() calles hashmap__new(), which may return
ERR_PTR(-ENOMEM). Instead of changing the checking one-by-one.
return NULL instead of ERR_PTR(-ENOMEM) to keep
consistent.
Signed-off-by: Miaoqian Lin <[email protected]>
---
tools/perf/util/expr.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/tools/perf/util/expr.c b/tools/perf/util/expr.c
index 1d532b9fed29..aabdc112300c 100644
--- a/tools/perf/util/expr.c
+++ b/tools/perf/util/expr.c
@@ -65,7 +65,13 @@ static bool key_equal(const void *key1, const void *key2,
struct hashmap *ids__new(void)
{
- return hashmap__new(key_hash, key_equal, NULL);
+ struct hashmap *hash;
+
+ hash = hashmap__new(key_hash, key_equal, NULL);
+ if (IS_ERR(hash))
+ return NULL;
+ else
+ return hash;
}
void ids__free(struct hashmap *ids)
--
2.17.1
Hi Miaoqian,
Fails to build due to missing import: "#import <linux/err.h>".
Could you please verify?
Other than that, it looks good to me. I shared the testing below:
On 13/12/2021 07:09, Miaoqian Lin wrote:
> callers of ids__new() function only do NULL checking for the return
> value. ids__new() calles hashmap__new(), which may return
> ERR_PTR(-ENOMEM). Instead of changing the checking one-by-one.
> return NULL instead of ERR_PTR(-ENOMEM) to keep
> consistent.
>
> Signed-off-by: Miaoqian Lin <[email protected]>
> ---
> tools/perf/util/expr.c | 8 +++++++-
> 1 file changed, 7 insertions(+), 1 deletion(-)
>
> diff --git a/tools/perf/util/expr.c b/tools/perf/util/expr.c
> index 1d532b9fed29..aabdc112300c 100644
> --- a/tools/perf/util/expr.c
> +++ b/tools/perf/util/expr.c
> @@ -65,7 +65,13 @@ static bool key_equal(const void *key1, const void *key2,
>
> struct hashmap *ids__new(void)
> {
> - return hashmap__new(key_hash, key_equal, NULL);
> + struct hashmap *hash;
> +
> + hash = hashmap__new(key_hash, key_equal, NULL);
> + if (IS_ERR(hash))
> + return NULL;
> + else
> + return hash;
> }
>
> void ids__free(struct hashmap *ids)
Before this patch, perf-test was segfaulting instead of a graceful fail.
I think this could have been an issue in the perf tool as well.
(I forced hashmap__new in "tools/perf/util/hashmap.c" to always return
the error for the purposes of the test).
$ make DEBUG=1 NO_LIBBPF=1 # builds with tools/perf/util/hashmap.c
$ ./perf test 7 -v
Couldn't bump rlimit(MEMLOCK), failures may take place when creating BPF maps, etc
7: Simple expression parser :
--- start ---
test child forked, pid 1953536
perf: Segmentation fault
Obtained 16 stack frames.
./perf(dump_stack+0x31) [0x559222b3ae48]
./perf(sighandler_dump_stack+0x33) [0x559222b3af30]
/lib/x86_64-linux-gnu/libc.so.6(+0x4620f) [0x7ff81df6220f]
./perf(hashmap__size+0x23) [0x559222bf9f47]
./perf(ids__union+0x5f) [0x559222be1f0e]
./perf(+0x2d9ba8) [0x559222ac7ba8]
./perf(+0x2da223) [0x559222ac8223]
./perf(+0x2a5fe9) [0x559222a93fe9]
./perf(+0x2a6119) [0x559222a94119]
./perf(+0x2a6de7) [0x559222a94de7]
./perf(cmd_test+0x25f) [0x559222a95686]
./perf(+0x2e4d25) [0x559222ad2d25]
./perf(+0x2e4faa) [0x559222ad2faa]
./perf(+0x2e50fd) [0x559222ad30fd]
./perf(main+0x29d) [0x559222ad3500]
/lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0xf2) [0x7ff81df430b2]
test child interrupted
---- end ----
Simple expression parser: FAILED!
After the patch:
$ make DEBUG=1 NO_LIBBPF=1
$ ./perf test 7 -v
Couldn't bump rlimit(MEMLOCK), failures may take place when creating BPF maps, etc
7: Simple expression parser :
--- start ---
test child forked, pid 1960026
FAILED tests/expr.c:16 ids__new
FAILED tests/expr.c:16 ids__new
FAILED tests/expr.c:73 ids_union (-1 != 0)
test child finished with -1
---- end ----
Simple expression parser: FAILED!
so with the missing import fixex:
Tested-by: German Gomez <[email protected]>
Reviewed-by: German Gomez <[email protected]>
This message appeared in my client as a separate thread, but it seems to
be a reply to a message from a different thread:
"In-Reply-To: <[email protected]>"
On 13/12/2021 07:09, Miaoqian Lin wrote:
> callers of ids__new() function only do NULL checking for the return
> value. ids__new() calles hashmap__new(), which may return
> ERR_PTR(-ENOMEM). Instead of changing the checking one-by-one.
> return NULL instead of ERR_PTR(-ENOMEM) to keep
> consistent.
>
> Signed-off-by: Miaoqian Lin <[email protected]>
> ---
> tools/perf/util/expr.c | 8 +++++++-
> 1 file changed, 7 insertions(+), 1 deletion(-)
>
> diff --git a/tools/perf/util/expr.c b/tools/perf/util/expr.c
> index 1d532b9fed29..aabdc112300c 100644
> --- a/tools/perf/util/expr.c
> +++ b/tools/perf/util/expr.c
> @@ -65,7 +65,13 @@ static bool key_equal(const void *key1, const void *key2,
>
> struct hashmap *ids__new(void)
> {
> - return hashmap__new(key_hash, key_equal, NULL);
> + struct hashmap *hash;
> +
> + hash = hashmap__new(key_hash, key_equal, NULL);
> + if (IS_ERR(hash))
> + return NULL;
> + else
> + return hash;
> }
>
> void ids__free(struct hashmap *ids)
On 13/12/2021 13:13, German Gomez wrote:
> [...]
>
> On 13/12/2021 07:09, Miaoqian Lin wrote:
>> callers of ids__new() function only do NULL checking for the return
>> value. ids__new() calles hashmap__new(), which may return
>> ERR_PTR(-ENOMEM). Instead of changing the checking one-by-one.
>> return NULL instead of ERR_PTR(-ENOMEM) to keep
>> consistent.
>>
>> Signed-off-by: Miaoqian Lin <[email protected]>
>> ---
>> tools/perf/util/expr.c | 8 +++++++-
>> 1 file changed, 7 insertions(+), 1 deletion(-)
>>
>> diff --git a/tools/perf/util/expr.c b/tools/perf/util/expr.c
>> index 1d532b9fed29..aabdc112300c 100644
>> --- a/tools/perf/util/expr.c
>> +++ b/tools/perf/util/expr.c
>> @@ -65,7 +65,13 @@ static bool key_equal(const void *key1, const void *key2,
>>
>> struct hashmap *ids__new(void)
>> {
>> - return hashmap__new(key_hash, key_equal, NULL);
>> + struct hashmap *hash;
>> +
>> + hash = hashmap__new(key_hash, key_equal, NULL);
>> + if (IS_ERR(hash))
>> + return NULL;
>> + else
>> + return hash;
Small nitpick but can remove the else branch and simply return at the
end? Your patch still compiles for me but I think most other functions
do that.
>> [...]