From: Mike Travis <travis@sgi.com>
To: Ingo Molnar <mingo@elte.hu>
Cc: Yinghai Lu <yinghai@kernel.org>,
David Rientjes <rientjes@google.com>,
Jack Steiner <steiner@sgi.com>, Robin Holt <holt@sgi.com>,
Len Brown <len.brown@intel.com>,
Thomas Gleixner <tglx@linutronix.de>,
"H. Peter Anvin" <hpa@zytor.com>,
Andrew Morton <akpm@linux-foundation.org>,
Yinghai Lu <yhlu.kernel@gmail.com>,
linux-acpi@vger.kernel.org, x86@kernel.org,
linux-kernel@vger.kernel.org, Tejun Heo <tj@kernel.org>,
Linus Torvalds <torvalds@linux-foundation.org>
Subject: Re: [PATCH 1/4] printk: Allocate kernel log buffer earlier
Date: Mon, 28 Feb 2011 11:29:02 -0800 [thread overview]
Message-ID: <4D6BF77E.2030107@sgi.com> (raw)
In-Reply-To: <20110228080642.GC1600@elte.hu>
Ingo Molnar wrote:
> * Yinghai Lu <yinghai@kernel.org> wrote:
>
>> + new_addr = memblock_alloc(new_log_buf_len, PAGE_SIZE);
>> + if (new_addr != MEMBLOCK_ERROR)
>> + new_log_buf = __va(new_addr);
>> + else
>> + new_log_buf = alloc_bootmem(new_log_buf_len);
>
> alloc_bootmem() can fail, especially if someone uses a too large boot parameter
> value - and your code does not check for failure.
alloc_bootmem does panic when it can't allocate memory.
Ingo, we have a "uvconfig" script that sets up the boot parameters (there
are many that are needed to be very specific). It sets up the log_buf_len
to be 8M. We will never overflow memory with that.
And if someone is stupid enough to try and allocate a log buffer that
consumes more memory than they have, then they have a different kind of
problem.
>
> Thanks,
>
> Ingo
next prev parent reply other threads:[~2011-02-28 19:29 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-02-25 18:06 [PATCH 0/4] init: Shrink early messages to prevent overflowing the kernel log buffer Mike Travis
2011-02-25 18:06 ` [PATCH 1/4] printk: Allocate kernel log buffer earlier Mike Travis
2011-02-27 12:09 ` Ingo Molnar
2011-02-27 12:15 ` Ingo Molnar
2011-02-28 1:34 ` Yinghai Lu
2011-02-28 8:01 ` Ingo Molnar
2011-02-28 19:26 ` Mike Travis
2011-03-01 7:35 ` Ingo Molnar
2011-02-28 8:06 ` Ingo Molnar
2011-02-28 19:18 ` Yinghai Lu
2011-02-28 19:29 ` Mike Travis [this message]
2011-02-28 19:23 ` Mike Travis
2011-02-28 19:46 ` Yinghai Lu
2011-02-28 20:02 ` Mike Travis
2011-02-28 22:59 ` Yinghai Lu
2011-03-31 0:41 ` [PATCH 1/2] memblock: add error return when CONFIG_HAVE_MEMBLOCK is not set Mike Travis
2011-03-31 1:40 ` Yinghai Lu
2011-03-31 15:23 ` Mike Travis
2011-03-31 16:17 ` Yinghai Lu
2011-04-07 19:43 ` Mike Travis
2011-04-08 6:40 ` Ingo Molnar
2011-03-01 7:42 ` [PATCH 1/4] printk: Allocate kernel log buffer earlier Ingo Molnar
2011-02-28 19:14 ` Mike Travis
2011-02-25 18:06 ` [PATCH 2/4] printk: Break out printk_time Mike Travis
2011-02-27 11:56 ` Ingo Molnar
2011-02-25 18:06 ` [PATCH 3/4] printk: Minimize time zero output Mike Travis
2011-02-25 18:06 ` [PATCH 4/4] x86: Minimize SRAT messages Mike Travis
2011-02-27 12:03 ` Ingo Molnar
2011-02-28 19:41 ` Mike Travis
2011-03-01 7:51 ` Ingo Molnar
2011-03-31 2:38 ` Len Brown
2011-03-31 4:40 ` Yinghai Lu
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