Re: [PATCH] perf trace: Fix IS_ERR() vs NULL check bug

[Ian Rogers]

On Fri, Feb 27, 2026 at 1:32 PM Namhyung Kim <namhyung@xxxxxxxxxx> wrote:
>
> On Thu, 26 Feb 2026 20:22:08 +0800, wangguangju@xxxxxxxx wrote:
> > The alloc_syscall_stats() function always returns an error pointer
> > (ERR_PTR) on failure.
> >
> > So replace NULL check with IS_ERR() check after calling
> > delete_syscall_stats() function.
> >
> >
> > [...]
> Applied to perf-tools-next, thanks!

This broke the "perf trace summary" test for me (run `perf test -v`).
The failing command under gdb shows:
```
$ gdb --args perf trace -s -- true
...
(gdb) r
...
Program received signal SIGSEGV, Segmentation fault.
0x0000555555672210 in delete_syscall_stats (syscall_stats=0x0) at
builtin-trace.c:1579
1579            hashmap__for_each_entry(syscall_stats, pos, bkt)
(gdb) l
1574            size_t bkt;
1575
1576            if (IS_ERR(syscall_stats))
1577                    return;
1578
1579            hashmap__for_each_entry(syscall_stats, pos, bkt)
1580                    zfree(&pos->pvalue);
1581            hashmap__free(syscall_stats);
1582    }
```

As NULL is false for IS_ERR I think the correct change is:
```
if (syscall_stats == NULL || IS_ERR(syscall_stats))
```

We seem to be routinely breaking tests, which may indicate a lot of
noise in the test output. I see many failures in the type profiling
test due to the typedef vs struct issue.

Thanks,
Ian

> Best regards,
> Namhyung
>
>