On Tue, Nov 26, 2024 at 11:46 AM Guanyou Chen <chenguanyou9...@gmail.com>
wrote:
> Hi lianbo
>
> test case is non-elf-vmcore, so all nt_prstatus_percpu invalid pointer.
>
>
Thanks for pointing out this. Can you help to try this one?
diff --git a/netdump.c b/netdump.c
index b4e2a5cb2037..b67bdad3c511 100644
--- a/netdump.c
+++ b/netdump.c
@@ -2768,7 +2768,8 @@ display_regs_from_elf_notes(int cpu, FILE *ofp)
}
}
- if ((cpu - skipped_count) >= nd->num_prstatus_notes &&
+ if (((cpu < 0 ) || (!nd->nt_prstatus_percpu[cpu]) ||
+ (cpu - skipped_count) >= nd->num_prstatus_notes) &&
!machine_type("MIPS")) {
error(INFO, "registers not collected for cpu %d\n", cpu);
return;
Lianbo
> Thanks
> Guanyou.
>
> lijiang <liji...@redhat.com> 于2024年11月26日周二 11:27写道：
>
>> Hi, Guanyou
>> Thank you for the fix.
>> On Mon, Nov 4, 2024 at 4:13 PM <devel-requ...@lists.crash-utility.osci.io>
>> wrote:
>>
>>> Date: Fri, 1 Nov 2024 18:01:27 +0800
>>> From: Guanyou Chen <chenguanyou9...@gmail.com>
>>> Subject: [Crash-utility] [PATCH] bugfix command "help -r" segv fault
>>> To: Lianbo <liji...@redhat.com>, Tao Liu <l...@redhat.com>,
>>> devel@lists.crash-utility.osci.io
>>> Message-ID:
>>> <CAHS3RMU3nuiqW4z=
>>> qo9roufadruxcalhyjnxwmcugodb_+3...@mail.gmail.com>
>>> Content-Type: multipart/mixed; boundary="00000000000065fc530625d705b8"
>>>
>>> --00000000000065fc530625d705b8
>>> Content-Type: multipart/alternative;
>>> boundary="00000000000065fc530625d705b6"
>>>
>>> --00000000000065fc530625d705b6
>>> Content-Type: text/plain; charset="UTF-8"
>>>
>>> Hi Lianbo, Tao
>>>
>>> When the ELF Note does not contain CPU registers,
>>> attempting to retrieve online CPU registers will cause a crash.
>>>
>>> After:
>>> CPU 6:
>>> help: registers not collected for cpu 6
>>> ...
>>>
>>> Signed-off-by: Guanyou.Chen <chenguan...@xiaomi.com>
>>> ---
>>> netdump.c | 16 ++++++++++++++++
>>> 1 file changed, 16 insertions(+)
>>>
>>> diff --git a/netdump.c b/netdump.c
>>> index 8ea5159..435793b 100644
>>> --- a/netdump.c
>>> +++ b/netdump.c
>>> @@ -2780,6 +2780,10 @@ display_regs_from_elf_notes(int cpu, FILE *ofp)
>>>
>>
>> I copied the code block here:
>> display_regs_from_elf_notes(int cpu, FILE *ofp)
>> {
>> Elf32_Nhdr *note32;
>> Elf64_Nhdr *note64;
>> size_t len;
>> char *user_regs;
>> int c, skipped_count;
>>
>> /*
>> * Kdump NT_PRSTATUS notes are only related to online cpus,
>> * so offline cpus should be skipped.
>> */
>> if (pc->flags2 & QEMU_MEM_DUMP_ELF)
>> skipped_count = 0;
>> else {
>> for (c = skipped_count = 0; c < cpu; c++) {
>> if (check_offline_cpu(c))
>> skipped_count++;
>> }
>> }
>>
>> if ((cpu - skipped_count) >= nd->num_prstatus_notes &&
>> !machine_type("MIPS")) {
>> error(INFO, "registers not collected for cpu %d\n", cpu);
>> return;
>> }
>> ...
>> Could you please point out why the above check does not work?
>>
>> BTW: I'm not sure if it can work for you, can you help to try this? Just
>> a guess.
>>
>> if (((cpu < 0 ) || (!dd->nt_prstatus_percpu[cpu])
>> || (cpu - skipped_count) >= nd->num_prstatus_notes) &&
>> !machine_type("MIPS")) {
>> error(INFO, "registers not collected for cpu %d\n", cpu);
>> return;
>> }
>>
>> Thanks
>> Lianbo
>>
>>
>> nd->nt_prstatus_percpu[cpu];
>>> else
>>> note64 = (Elf64_Nhdr *)nd->nt_prstatus;
>>> + if (!note64) {
>>> + error(INFO, "registers not collected for cpu %d\n", cpu);
>>> + return;
>>> + }
>>> len = sizeof(Elf64_Nhdr);
>>> len = roundup(len + note64->n_namesz, 4);
>>> len = roundup(len + note64->n_descsz, 4);
>>> @@ -2820,6 +2824,10 @@ display_regs_from_elf_notes(int cpu, FILE *ofp)
>>> nd->nt_prstatus_percpu[cpu];
>>> else
>>> note32 = (Elf32_Nhdr *)nd->nt_prstatus;
>>> + if (!note32) {
>>> + error(INFO, "registers not collected for cpu %d\n", cpu);
>>> + return;
>>> + }
>>> len = sizeof(Elf32_Nhdr);
>>> len = roundup(len + note32->n_namesz, 4);
>>> len = roundup(len + note32->n_descsz, 4);
>>> @@ -2857,6 +2865,10 @@ display_regs_from_elf_notes(int cpu, FILE *ofp)
>>> else
>>> note64 = (Elf64_Nhdr *)nd->nt_prstatus;
>>>
>>> + if (!note64) {
>>> + error(INFO, "registers not collected for cpu %d\n", cpu);
>>> + return;
>>> + }
>>> prs = (struct ppc64_elf_prstatus *)
>>> ((char *)note64 + sizeof(Elf64_Nhdr) + note64->n_namesz);
>>> prs = (struct ppc64_elf_prstatus *)roundup((ulong)prs, 4);
>>> @@ -2903,6 +2915,10 @@ display_regs_from_elf_notes(int cpu, FILE *ofp)
>>> nd->nt_prstatus_percpu[cpu];
>>> else
>>> note64 = (Elf64_Nhdr *)nd->nt_prstatus;
>>> + if (!note64) {
>>> + error(INFO, "registers not collected for cpu %d\n", cpu);
>>> + return;
>>> + }
>>> len = sizeof(Elf64_Nhdr);
>>> len = roundup(len + note64->n_namesz, 4);
>>> len = roundup(len + note64->n_descsz, 4);
>>> --
>>> 2.34.1
>>>
>>> Guanyou.
>>> Thanks
>>>
>>
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