From: Arvind Sankar <nivedita@alum.mit.edu>
To: x86@kernel.org, Joerg Roedel <jroedel@suse.de>
Cc: linux-kernel@vger.kernel.org
Subject: [PATCH 5/5] x86/head/64: Disable stack protection for head$(BITS).o
Date: Wed, 7 Oct 2020 15:53:51 -0400 [thread overview]
Message-ID: <20201007195351.776555-6-nivedita@alum.mit.edu> (raw)
In-Reply-To: <20201007195351.776555-1-nivedita@alum.mit.edu>
On 64-bit, the startup_64_setup_env() function added in
866b556efa12 ("x86/head/64: Install startup GDT")
has stack protection enabled because of set_bringup_idt_handler().
At this point, %gs is not yet initialized, and this doesn't cause a
crash only because the #PF handler from the decompressor stub is still
installed and handles the page fault.
Disable stack protection for the whole file, and do it on 32-bit as
well to avoid surprises.
Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
---
arch/x86/kernel/Makefile | 2 ++
1 file changed, 2 insertions(+)
diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile
index 04ceea8f4a89..68608bd892c0 100644
--- a/arch/x86/kernel/Makefile
+++ b/arch/x86/kernel/Makefile
@@ -47,6 +47,8 @@ endif
# non-deterministic coverage.
KCOV_INSTRUMENT := n
+CFLAGS_head$(BITS).o += -fno-stack-protector
+
CFLAGS_irq.o := -I $(srctree)/$(src)/../include/asm/trace
obj-y := process_$(BITS).o signal.o
--
2.26.2
next prev parent reply other threads:[~2020-10-07 19:54 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-07 19:53 [PATCH 0/5] Couple of bugfixes to sev-es series Arvind Sankar
2020-10-07 19:53 ` [PATCH 1/5] x86/boot: Initialize boot_params in startup code Arvind Sankar
2020-10-08 9:04 ` Joerg Roedel
2020-10-08 13:44 ` Arvind Sankar
2020-10-07 19:53 ` [PATCH 2/5] x86/boot: Move get_cmd_line_ptr() and COMMAND_LINE_SIZE into misc.h Arvind Sankar
2020-10-08 9:11 ` Joerg Roedel
2020-10-08 9:30 ` Borislav Petkov
2020-10-08 13:47 ` Arvind Sankar
2020-10-08 15:10 ` Borislav Petkov
2020-10-08 15:30 ` Arvind Sankar
2020-10-08 16:16 ` Borislav Petkov
2020-10-07 19:53 ` [PATCH 3/5] x86/boot/64: Change add_identity_map() to take size for ease of use Arvind Sankar
2020-10-08 9:14 ` Joerg Roedel
2020-10-08 13:49 ` Arvind Sankar
2020-10-07 19:53 ` [PATCH 4/5] x86/boot/64: Explicitly map boot_params and command line Arvind Sankar
2020-10-08 9:17 ` Joerg Roedel
2020-10-08 9:48 ` Joerg Roedel
2020-10-08 13:57 ` Arvind Sankar
2020-10-07 19:53 ` Arvind Sankar [this message]
2020-10-08 8:42 ` [PATCH 5/5] x86/head/64: Disable stack protection for head$(BITS).o Joerg Roedel
2020-10-08 14:52 ` Arvind Sankar
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