在 2021年04月13日 07:34, HAGIO KAZUHITO(萩尾 一仁) 写道:
> Hi Lianbo,
>
> -----Original Message-----
>> 在 2021年04月02日 15:02, HAGIO KAZUHITO(萩尾 一仁) 写道:
>>> -----Original Message-----
>>>> In the show_member_offset() function, when trying to handle function
>>>> pointers, the case for "(*" is handled. However, if the function
>>>> pointer returns a pointer or a pointer to a pointer, then the
>>>> condition is unhandled. This results in the offset not being printed.
>>>>
>>>> Fix by first checking if the member is potentially a function pointer,
>>>> then checking if it returns a pointer or a pointer to a pointer.
>>>>
>>>> Signed-off-by: John Pittman <jpittman@xxxxxxxxxx>
>>>
>>> Good catch... I've confirmed that the patch works as expected with RHEL7's
>>> struct offload_callbacks:
>>>
>>> crash> struct -o offload_callbacks
>>> struct offload_callbacks {
>>> [0] struct sk_buff *(*gso_segment)(struct sk_buff *, netdev_features_t);
>>> [8] struct sk_buff **(*gro_receive)(struct sk_buff **, struct sk_buff *);
>
> This output is the one with the patch, and
>
>>> [16] int (*gro_complete)(struct sk_buff *, int);
>>> }
>>> SIZE: 24
>>
>> This should be a good example for the case described in patch log. But I didn't
>> reproduce it on rhel7 before applying this patch, it's strange.
>> ...
>> KERNEL: /usr/lib/debug/lib/modules/3.10.0-1160.24.1.el7.x86_64/vmlinux
>> ...
>> RELEASE: 3.10.0-1160.24.1.el7.x86_64
>> VERSION: #1 SMP Thu Mar 25 21:21:56 UTC 2021
>> MACHINE: x86_64 (2892 Mhz)
>> MEMORY: 4 GB
>> PID: 7815
>> COMMAND: "crash"
>> TASK: ffffa10210512100 [THREAD_INFO: ffffa10189b34000]
>> CPU: 1
>> STATE: TASK_RUNNING (ACTIVE)
>>
>> crash> struct -o offload_callbacks
>> struct offload_callbacks {
>> struct sk_buff *(*gso_segment)(struct sk_buff *, netdev_features_t);
>> struct sk_buff **(*gro_receive)(struct sk_buff **, struct sk_buff *);
> ^^^^
> There are no offsets here, you're reproducing the issue, I think?
>
That's right, I ignored the offset.
Thank you for the explanation in detail. Kazu and John Pittman.
Acked-by: Lianbo Jiang <lijiang@xxxxxxxxxx>
> Thanks,
> Kazu
>
>> [16] int (*gro_complete)(struct sk_buff *, int);
>> }
>> SIZE: 24
>>
>> Do you happen to know how to reproduce this issue? John Pittman.
>>
>> Thanks.
>> Lianbo
>>
>>>
>>> Acked-by: Kazuhito Hagio <k-hagio-ab@xxxxxxx>
>>>
>>> Thanks,
>>> Kazu
>>>
>>>> ---
>>>> symbols.c | 11 +++++++++--
>>>> 1 file changed, 9 insertions(+), 2 deletions(-)
>>>>
>>>> diff --git a/symbols.c b/symbols.c
>>>> index a2d5c6c..5d7da6e 100644
>>>> --- a/symbols.c
>>>> +++ b/symbols.c
>>>> @@ -8356,8 +8356,15 @@ show_member_offset(FILE *ofp, struct datatype_member *dm, char *inbuf)
>>>> }
>>>> } else if (c) {
>>>> for (i = 0; i < c; i++) {
>>>> - if (STRNEQ(arglist[i], "(*")) {
>>>> - target = arglist[i]+2;
>>>> + if (strstr(inbuf, "(*")) {
>>>> + if (STRNEQ(arglist[i], "(*"))
>>>> + target = arglist[i]+2;
>>>> + else if (STRNEQ(arglist[i], "*(*"))
>>>> + target = arglist[i]+3;
>>>> + else if (STRNEQ(arglist[i], "**(*"))
>>>> + target = arglist[i]+4;
>>>> + else
>>>> + continue;
>>>> if (!(t1 = strstr(target, ")")))
>>>> continue;
>>>> *t1 = NULLCHAR;
>>>> --
>>>> 2.17.2
>>>
>
--
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