From: Mahesh Jagannath Salgaonkar <mahesh@linux.vnet.ibm.com>
To: Dave Young <dyoung@redhat.com>, Xunlei Pang <xlpang@redhat.com>
Cc: Baoquan He <bhe@redhat.com>,
kexec@lists.infradead.org, Petr Tesarik <ptesarik@suse.cz>,
linux-kernel@vger.kernel.org,
Eric Biederman <ebiederm@xmission.com>,
Hari Bathini <hbathini@linux.vnet.ibm.com>,
akpm@linux-foundation.org, linuxppc-dev@lists.ozlabs.org
Subject: Re: [PATCH v4 2/3] powerpc/fadump: Use the correct VMCOREINFO_NOTE_SIZE for phdr
Date: Thu, 27 Apr 2017 13:08:24 +0530 [thread overview]
Message-ID: <8a4b3bcc-466c-4f8c-c813-c57a600bf038@linux.vnet.ibm.com> (raw)
In-Reply-To: <20170426071114.GC5381@dhcp-128-65.nay.redhat.com>
On 04/26/2017 12:41 PM, Dave Young wrote:
> Ccing ppc list
> On 04/20/17 at 07:39pm, Xunlei Pang wrote:
>> vmcoreinfo_max_size stands for the vmcoreinfo_data, the
>> correct one we should use is vmcoreinfo_note whose total
>> size is VMCOREINFO_NOTE_SIZE.
>>
>> Like explained in commit 77019967f06b ("kdump: fix exported
>> size of vmcoreinfo note"), it should not affect the actual
>> function, but we better fix it, also this change should be
>> safe and backward compatible.
>>
>> After this, we can get rid of variable vmcoreinfo_max_size,
>> let's use the corresponding macros directly, fewer variables
>> means more safety for vmcoreinfo operation.
>>
>> Cc: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
>> Cc: Hari Bathini <hbathini@linux.vnet.ibm.com>
>> Signed-off-by: Xunlei Pang <xlpang@redhat.com>
Reviewed-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Thanks,
-Mahesh.
>> ---
>> v3->v4:
>> -Rebased on the latest linux-next
>>
>> arch/powerpc/kernel/fadump.c | 3 +--
>> include/linux/crash_core.h | 1 -
>> kernel/crash_core.c | 3 +--
>> 3 files changed, 2 insertions(+), 5 deletions(-)
>>
>> diff --git a/arch/powerpc/kernel/fadump.c b/arch/powerpc/kernel/fadump.c
>> index 466569e..7bd6cd0 100644
>> --- a/arch/powerpc/kernel/fadump.c
>> +++ b/arch/powerpc/kernel/fadump.c
>> @@ -893,8 +893,7 @@ static int fadump_create_elfcore_headers(char *bufp)
>>
>> phdr->p_paddr = fadump_relocate(paddr_vmcoreinfo_note());
>> phdr->p_offset = phdr->p_paddr;
>> - phdr->p_memsz = vmcoreinfo_max_size;
>> - phdr->p_filesz = vmcoreinfo_max_size;
>> + phdr->p_memsz = phdr->p_filesz = VMCOREINFO_NOTE_SIZE;
>>
>> /* Increment number of program headers. */
>> (elf->e_phnum)++;
>> diff --git a/include/linux/crash_core.h b/include/linux/crash_core.h
>> index ba283a2..7d6bc7b 100644
>> --- a/include/linux/crash_core.h
>> +++ b/include/linux/crash_core.h
>> @@ -55,7 +55,6 @@
>>
>> extern u32 *vmcoreinfo_note;
>> extern size_t vmcoreinfo_size;
>> -extern size_t vmcoreinfo_max_size;
>>
>> Elf_Word *append_elf_note(Elf_Word *buf, char *name, unsigned int type,
>> void *data, size_t data_len);
>> diff --git a/kernel/crash_core.c b/kernel/crash_core.c
>> index 0321f04..43cdb00 100644
>> --- a/kernel/crash_core.c
>> +++ b/kernel/crash_core.c
>> @@ -16,7 +16,6 @@
>> /* vmcoreinfo stuff */
>> static unsigned char *vmcoreinfo_data;
>> size_t vmcoreinfo_size;
>> -size_t vmcoreinfo_max_size = VMCOREINFO_BYTES;
>> u32 *vmcoreinfo_note;
>>
>> /*
>> @@ -343,7 +342,7 @@ void vmcoreinfo_append_str(const char *fmt, ...)
>> r = vscnprintf(buf, sizeof(buf), fmt, args);
>> va_end(args);
>>
>> - r = min(r, vmcoreinfo_max_size - vmcoreinfo_size);
>> + r = min(r, VMCOREINFO_BYTES - vmcoreinfo_size);
>>
>> memcpy(&vmcoreinfo_data[vmcoreinfo_size], buf, r);
>>
>> --
>> 1.8.3.1
>>
>>
>> _______________________________________________
>> kexec mailing list
>> kexec@lists.infradead.org
>> http://lists.infradead.org/mailman/listinfo/kexec
>
> Reviewed-by: Dave Young <dyoung@redhat.com>
>
> Thanks
> Dave
>
next prev parent reply other threads:[~2017-04-27 7:39 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-04-20 11:39 [PATCH v4 1/3] kexec: Move vmcoreinfo out of the kernel's .bss section Xunlei Pang
2017-04-20 11:39 ` [PATCH v4 2/3] powerpc/fadump: Use the correct VMCOREINFO_NOTE_SIZE for phdr Xunlei Pang
2017-04-21 0:55 ` Xunlei Pang
2017-04-26 7:11 ` Dave Young
2017-04-27 7:38 ` Mahesh Jagannath Salgaonkar [this message]
2017-04-20 11:39 ` [PATCH v4 3/3] kdump: Protect vmcoreinfo data under the crash memory Xunlei Pang
2017-04-26 7:09 ` Dave Young
2017-04-26 9:21 ` Xunlei Pang
2017-04-27 2:56 ` Dave Young
2017-04-20 14:24 ` [PATCH v4 1/3] kexec: Move vmcoreinfo out of the kernel's .bss section Juergen Gross
2017-04-24 15:18 ` Michael Holzheu
2017-04-26 7:19 ` Dave Young
2017-04-26 9:51 ` Xunlei Pang
2017-04-26 10:18 ` Xunlei Pang
2017-04-27 3:06 ` Dave Young
2017-04-27 5:25 ` Xunlei Pang
2017-04-27 5:44 ` Dave Young
2017-04-27 6:08 ` Xunlei Pang
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