From: ebiederm@xmission.com (Eric W. Biederman)
To: "H. Peter Anvin" <hpa@zytor.com>
Cc: Tejun Heo <tj@kernel.org>, hacklu <embedway.linux@gmail.com>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 2/2] x86, boot: Optimize the elf header handling.
Date: Sun, 08 Jul 2012 23:50:38 -0700 [thread overview]
Message-ID: <87k3yd5sxt.fsf@xmission.com> (raw)
In-Reply-To: <4FF0B891.8080804@zytor.com> (H. Peter Anvin's message of "Sun, 01 Jul 2012 13:52:33 -0700")
"H. Peter Anvin" <hpa@zytor.com> writes:
> On 07/01/2012 01:40 PM, Eric W. Biederman wrote:
>>
>> So I have tracked down part of the crazyness.
>> CONFIG_RODATA actually uses 2MB alignment, making
>> -z max_page_size=4096 a bit questionable.
>>
>
> Questionable how? It's not really like it matters since we're not going
> to mmap the ELF.
Questionable as in the current elf loader in misc.c relies on the fact
that there is an almost a fixed offset between physical addresses and
file offsets for all of the PT_LOAD segments in the Elf header.
In fact CONFIG_RODATA && CONFIG_X86_64 && CONFIG_SMP in combination with
-z max_page_size=4096 fails to boot. The Elf loader in misc.c starts
coping from lower addresses to higher addresses, instead of higher
addresses to lower and that fails miserably.
But -z max_page_size=4096 is not the problem the ELF loader is.
Eric
next prev parent reply other threads:[~2012-07-09 6:51 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-05-17 5:56 why the decompressed procedure move kernel from address 0x100000(1M) to 0x1000000(16M) +x hacklu
2012-06-02 23:48 ` Eric W. Biederman
2012-06-03 3:10 ` H. Peter Anvin
2012-06-03 8:41 ` Eric W. Biederman
2012-06-03 13:01 ` H. Peter Anvin
2012-06-03 20:30 ` [PATCH 1/2] x86, boot: Don't overlap the compressed and non-compressed image Eric W. Biederman
2012-06-03 20:32 ` [PATCH 2/2] x86, boot: Optimize the elf header handling Eric W. Biederman
2012-07-01 14:56 ` [tip:x86/boot] " tip-bot for Eric W. Biederman
2012-07-01 15:04 ` [PATCH 2/2] " H. Peter Anvin
2012-07-01 15:34 ` H. Peter Anvin
2012-07-01 16:08 ` Eric W. Biederman
2012-07-01 16:11 ` H. Peter Anvin
2012-07-01 16:26 ` Eric W. Biederman
2012-07-01 16:44 ` H. Peter Anvin
2012-07-01 17:09 ` Eric W. Biederman
2012-07-01 17:15 ` H. Peter Anvin
2012-07-01 18:25 ` Eric W. Biederman
2012-07-01 18:37 ` H. Peter Anvin
2012-07-01 19:20 ` Eric W. Biederman
2012-07-01 19:23 ` H. Peter Anvin
2012-07-01 20:40 ` Eric W. Biederman
2012-07-01 20:52 ` H. Peter Anvin
2012-07-09 6:50 ` Eric W. Biederman [this message]
2012-07-09 6:52 ` [PATCH 1/4] x86 boot: Jump to the entry point address in the elf header Eric W. Biederman
2012-07-09 6:53 ` [PATCH 2/4] x86 boot: Optimize the elf header handling Eric W. Biederman
2012-07-09 6:55 ` [PATCH 3/4] x86 boot: When building vmlinux.bin properly precompute the memory image Eric W. Biederman
2012-07-09 6:56 ` [PATCH 4/4] x86 boot: Tell ld the kernel doesn't want 2MB file offset alignment Eric W. Biederman
2012-07-09 6:59 ` [PATCH 1/4] x86 boot: Jump to the entry point address in the elf header Eric W. Biederman
2012-07-02 16:56 ` [PATCH 2/2] x86, boot: Optimize the elf header handling Tejun Heo
2012-07-09 7:03 ` Eric W. Biederman
2012-07-01 2:23 ` [PATCH 1/2] x86, boot: Don't overlap the compressed and non-compressed image Eric W. Biederman
2012-07-01 2:32 ` H. Peter Anvin
2012-07-01 5:22 ` Eric W. Biederman
2012-07-01 14:55 ` [tip:x86/boot] x86, boot: Don' t " tip-bot for Eric W. Biederman
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