[PATCH AUTOSEL 4.14 12/22] x86/boot: Use unsigned comparison for addresses

All of lore.kernel.org
 help / color / mirror / Atom feed

From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Arvind Sankar <nivedita@alum.mit.edu>,
	Ard Biesheuvel <ardb@kernel.org>, Ingo Molnar <mingo@kernel.org>,
	Sasha Levin <sashal@kernel.org>
Subject: [PATCH AUTOSEL 4.14 12/22] x86/boot: Use unsigned comparison for addresses
Date: Thu,  9 Apr 2020 23:50:34 -0400	[thread overview]
Message-ID: <20200410035044.9698-12-sashal@kernel.org> (raw)
In-Reply-To: <20200410035044.9698-1-sashal@kernel.org>

From: Arvind Sankar <nivedita@alum.mit.edu>

[ Upstream commit 81a34892c2c7c809f9c4e22c5ac936ae673fb9a2 ]

The load address is compared with LOAD_PHYSICAL_ADDR using a signed
comparison currently (using jge instruction).

When loading a 64-bit kernel using the new efi32_pe_entry() point added by:

  97aa276579b2 ("efi/x86: Add true mixed mode entry point into .compat section")

using Qemu with -m 3072, the firmware actually loads us above 2Gb,
resulting in a very early crash.

Use the JAE instruction to perform a unsigned comparison instead, as physical
addresses should be considered unsigned.

Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20200301230436.2246909-6-nivedita@alum.mit.edu
Link: https://lore.kernel.org/r/20200308080859.21568-14-ardb@kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/x86/boot/compressed/head_32.S | 2 +-
 arch/x86/boot/compressed/head_64.S | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/arch/x86/boot/compressed/head_32.S b/arch/x86/boot/compressed/head_32.S
index 37380c0d59996..01d628ea34024 100644
--- a/arch/x86/boot/compressed/head_32.S
+++ b/arch/x86/boot/compressed/head_32.S
@@ -106,7 +106,7 @@ ENTRY(startup_32)
 	notl	%eax
 	andl    %eax, %ebx
 	cmpl	$LOAD_PHYSICAL_ADDR, %ebx
-	jge	1f
+	jae	1f
 #endif
 	movl	$LOAD_PHYSICAL_ADDR, %ebx
 1:
diff --git a/arch/x86/boot/compressed/head_64.S b/arch/x86/boot/compressed/head_64.S
index 39fdede523f21..a25127916e679 100644
--- a/arch/x86/boot/compressed/head_64.S
+++ b/arch/x86/boot/compressed/head_64.S
@@ -105,7 +105,7 @@ ENTRY(startup_32)
 	notl	%eax
 	andl	%eax, %ebx
 	cmpl	$LOAD_PHYSICAL_ADDR, %ebx
-	jge	1f
+	jae	1f
 #endif
 	movl	$LOAD_PHYSICAL_ADDR, %ebx
 1:
@@ -280,7 +280,7 @@ ENTRY(startup_64)
 	notq	%rax
 	andq	%rax, %rbp
 	cmpq	$LOAD_PHYSICAL_ADDR, %rbp
-	jge	1f
+	jae	1f
 #endif
 	movq	$LOAD_PHYSICAL_ADDR, %rbp
 1:
-- 
2.20.1

next prev parent reply	other threads:[~2020-04-10  3:51 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-04-10  3:50 [PATCH AUTOSEL 4.14 01/22] null_blk: Fix the null_add_dev() error path Sasha Levin
2020-04-10  3:50 ` [PATCH AUTOSEL 4.14 02/22] null_blk: Handle null_add_dev() failures properly Sasha Levin
2020-04-10  3:50 ` [PATCH AUTOSEL 4.14 03/22] null_blk: fix spurious IO errors after failed past-wp access Sasha Levin
2020-04-10  3:50 ` [PATCH AUTOSEL 4.14 04/22] x86: Don't let pgprot_modify() change the page encryption bit Sasha Levin
2020-04-10  3:50 ` [PATCH AUTOSEL 4.14 05/22] block: keep bdi->io_pages in sync with max_sectors_kb for stacked devices Sasha Levin
2020-04-10  3:50 ` [PATCH AUTOSEL 4.14 06/22] irqchip/versatile-fpga: Handle chained IRQs properly Sasha Levin
2020-04-10  3:50   ` Sasha Levin
2020-04-10  3:50 ` [PATCH AUTOSEL 4.14 07/22] sched: Avoid scale real weight down to zero Sasha Levin
2020-04-10  3:50 ` [PATCH AUTOSEL 4.14 08/22] selftests/x86/ptrace_syscall_32: Fix no-vDSO segfault Sasha Levin
2020-04-10  3:50 ` [PATCH AUTOSEL 4.14 09/22] PCI/switchtec: Fix init_completion race condition with poll_wait() Sasha Levin
2020-04-10  3:50 ` [PATCH AUTOSEL 4.14 10/22] libata: Remove extra scsi_host_put() in ata_scsi_add_hosts() Sasha Levin
2020-04-10  3:50 ` [Cluster-devel] [PATCH AUTOSEL 4.14 11/22] gfs2: Don't demote a glock until its revokes are written Sasha Levin
2020-04-10  3:50   ` Sasha Levin
2020-04-10  3:50 ` Sasha Levin [this message]
2020-04-10  3:50 ` [PATCH AUTOSEL 4.14 13/22] efi/x86: Ignore the memory attributes table on i386 Sasha Levin
2020-04-10  3:50 ` [PATCH AUTOSEL 4.14 14/22] genirq/irqdomain: Check pointer in irq_domain_alloc_irqs_hierarchy() Sasha Levin
2020-04-10  3:50 ` [PATCH AUTOSEL 4.14 15/22] block: Fix use-after-free issue accessing struct io_cq Sasha Levin
2020-04-10  3:50 ` [PATCH AUTOSEL 4.14 16/22] usb: dwc3: core: add support for disabling SS instances in park mode Sasha Levin
2020-04-10  3:50 ` [PATCH AUTOSEL 4.14 17/22] irqchip/gic-v4: Provide irq_retrigger to avoid circular locking dependency Sasha Levin
2020-04-10  3:50 ` [PATCH AUTOSEL 4.14 18/22] locking/lockdep: Avoid recursion in lockdep_count_{for,back}ward_deps() Sasha Levin
2020-04-10  3:50 ` [PATCH AUTOSEL 4.14 19/22] block, bfq: fix use-after-free in bfq_idle_slice_timer_body Sasha Levin
2020-04-10  3:50 ` [PATCH AUTOSEL 4.14 20/22] btrfs: hold a ref on the root in btrfs_recover_relocation Sasha Levin
2020-04-10  3:50 ` [PATCH AUTOSEL 4.14 21/22] btrfs: remove a BUG_ON() from merge_reloc_roots() Sasha Levin
2020-04-10  3:50 ` [PATCH AUTOSEL 4.14 22/22] btrfs: track reloc roots based on their commit root bytenr Sasha Levin

find likely ancestor, descendant, or conflicting patches for this message:
( dfblob:37380c0d5999 dfblob:01d628ea3402 dfblob:39fdede523f2
dfblob:a25127916e67 )
 OR (
bs:"[PATCH AUTOSEL 4.14 12/22] x86/boot: Use unsigned comparison for addresses" )
	(help)

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20200410035044.9698-12-sashal@kernel.org \
    --to=sashal@kernel.org \
    --cc=ardb@kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mingo@kernel.org \
    --cc=nivedita@alum.mit.edu \
    --cc=stable@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Be sure your reply has a Subject: header at the top and a blank line before the message body.

This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.