From: Joerg Roedel <jroedel@suse.de>
To: Arvind Sankar <nivedita@alum.mit.edu>
Cc: x86@kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 5/5] x86/head/64: Disable stack protection for head$(BITS).o
Date: Thu, 8 Oct 2020 10:42:19 +0200 [thread overview]
Message-ID: <20201008084219.GC3209@suse.de> (raw)
In-Reply-To: <20201007195351.776555-6-nivedita@alum.mit.edu>
On Wed, Oct 07, 2020 at 03:53:51PM -0400, Arvind Sankar wrote:
> On 64-bit, the startup_64_setup_env() function added in
> 866b556efa12 ("x86/head/64: Install startup GDT")
> has stack protection enabled because of set_bringup_idt_handler().
>
> At this point, %gs is not yet initialized, and this doesn't cause a
> crash only because the #PF handler from the decompressor stub is still
> installed and handles the page fault.
Hmm, that is weird. Can you please share your config with which this
happens? I have a commit in my local branch which disables page-faulting
in the pre-decompression code before jumping to the uncompressed kernel
image, and it did not break anything here.
Also, what compiler did you use to trigger this?
next prev parent reply other threads:[~2020-10-08 8:42 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-07 19:53 [PATCH 0/5] Couple of bugfixes to sev-es series Arvind Sankar
2020-10-07 19:53 ` [PATCH 1/5] x86/boot: Initialize boot_params in startup code Arvind Sankar
2020-10-08 9:04 ` Joerg Roedel
2020-10-08 13:44 ` Arvind Sankar
2020-10-07 19:53 ` [PATCH 2/5] x86/boot: Move get_cmd_line_ptr() and COMMAND_LINE_SIZE into misc.h Arvind Sankar
2020-10-08 9:11 ` Joerg Roedel
2020-10-08 9:30 ` Borislav Petkov
2020-10-08 13:47 ` Arvind Sankar
2020-10-08 15:10 ` Borislav Petkov
2020-10-08 15:30 ` Arvind Sankar
2020-10-08 16:16 ` Borislav Petkov
2020-10-07 19:53 ` [PATCH 3/5] x86/boot/64: Change add_identity_map() to take size for ease of use Arvind Sankar
2020-10-08 9:14 ` Joerg Roedel
2020-10-08 13:49 ` Arvind Sankar
2020-10-07 19:53 ` [PATCH 4/5] x86/boot/64: Explicitly map boot_params and command line Arvind Sankar
2020-10-08 9:17 ` Joerg Roedel
2020-10-08 9:48 ` Joerg Roedel
2020-10-08 13:57 ` Arvind Sankar
2020-10-07 19:53 ` [PATCH 5/5] x86/head/64: Disable stack protection for head$(BITS).o Arvind Sankar
2020-10-08 8:42 ` Joerg Roedel [this message]
2020-10-08 14:52 ` Arvind Sankar
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