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From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	stable@vger.kernel.org, Josh Poimboeuf <jpoimboe@redhat.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Ben Hutchings <ben@decadent.org.uk>
Subject: [PATCH 4.4 20/21] x86/entry/64: Use JMP instead of JMPQ
Date: Fri,  9 Aug 2019 15:45:24 +0200	[thread overview]
Message-ID: <20190809134242.383550628@linuxfoundation.org> (raw)
In-Reply-To: <20190809134241.565496442@linuxfoundation.org>

From: Josh Poimboeuf <jpoimboe@redhat.com>

commit 64dbc122b20f75183d8822618c24f85144a5a94d upstream.

Somehow the swapgs mitigation entry code patch ended up with a JMPQ
instruction instead of JMP, where only the short jump is needed.  Some
assembler versions apparently fail to optimize JMPQ into a two-byte JMP
when possible, instead always using a 7-byte JMP with relocation.  For
some reason that makes the entry code explode with a #GP during boot.

Change it back to "JMP" as originally intended.

Fixes: 18ec54fdd6d1 ("x86/speculation: Prepare entry code for Spectre v1 swapgs mitigations")
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
[bwh: Backported to 4.4: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 arch/x86/entry/entry_64.S |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -567,7 +567,7 @@ END(irq_entries_start)
 #ifdef CONFIG_CONTEXT_TRACKING
 	call enter_from_user_mode
 #endif
-	jmpq	2f
+	jmp	2f
 1:
 	FENCE_SWAPGS_KERNEL_ENTRY
 2:



  parent reply	other threads:[~2019-08-09 13:46 UTC|newest]

Thread overview: 27+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-08-09 13:45 [PATCH 4.4 00/21] 4.4.189-stable review Greg Kroah-Hartman
2019-08-09 13:45 ` [PATCH 4.4 01/21] arm64: cpufeature: Fix CTR_EL0 field definitions Greg Kroah-Hartman
2019-08-09 13:45 ` [PATCH 4.4 02/21] arm64: cpufeature: Fix feature comparison for CTR_EL0.{CWG,ERG} Greg Kroah-Hartman
2019-08-09 13:45 ` [PATCH 4.4 03/21] netfilter: nfnetlink_acct: validate NFACCT_QUOTA parameter Greg Kroah-Hartman
2019-08-09 13:45 ` [PATCH 4.4 04/21] HID: Add quirk for HP X1200 PIXART OEM mouse Greg Kroah-Hartman
2019-08-09 13:45 ` [PATCH 4.4 05/21] tcp: be more careful in tcp_fragment() Greg Kroah-Hartman
2019-08-09 13:45 ` [PATCH 4.4 06/21] atm: iphase: Fix Spectre v1 vulnerability Greg Kroah-Hartman
2019-08-09 13:45 ` [PATCH 4.4 07/21] net: bridge: delete local fdb on device init failure Greg Kroah-Hartman
2019-08-09 13:45 ` [PATCH 4.4 08/21] net: fix ifindex collision during namespace removal Greg Kroah-Hartman
2019-08-09 13:45 ` [PATCH 4.4 09/21] tipc: compat: allow tipc commands without arguments Greg Kroah-Hartman
2019-08-09 13:45 ` [PATCH 4.4 10/21] net: sched: Fix a possible null-pointer dereference in dequeue_func() Greg Kroah-Hartman
2019-08-09 13:45 ` [PATCH 4.4 11/21] net/mlx5: Use reversed order when unregister devices Greg Kroah-Hartman
2019-08-09 13:45 ` [PATCH 4.4 12/21] bnx2x: Disable multi-cos feature Greg Kroah-Hartman
2019-08-09 13:45 ` [PATCH 4.4 13/21] compat_ioctl: pppoe: fix PPPOEIOCSFWD handling Greg Kroah-Hartman
2019-08-09 13:45 ` [PATCH 4.4 14/21] block: blk_init_allocated_queue() set q->fq as NULL in the fail case Greg Kroah-Hartman
2019-08-09 13:45 ` [PATCH 4.4 15/21] spi: bcm2835: Fix 3-wire mode if DMA is enabled Greg Kroah-Hartman
2019-08-09 13:45 ` [PATCH 4.4 16/21] x86: cpufeatures: Sort feature word 7 Greg Kroah-Hartman
2019-08-09 13:45 ` [PATCH 4.4 17/21] x86/entry/64: Fix context tracking state warning when load_gs_index fails Greg Kroah-Hartman
2019-08-09 13:45 ` [PATCH 4.4 18/21] x86/speculation: Prepare entry code for Spectre v1 swapgs mitigations Greg Kroah-Hartman
2019-08-09 13:45 ` [PATCH 4.4 19/21] x86/speculation: Enable " Greg Kroah-Hartman
2019-08-09 13:45 ` Greg Kroah-Hartman [this message]
2019-08-09 13:45 ` [PATCH 4.4 21/21] x86/speculation/swapgs: Exclude ATOMs from speculation through SWAPGS Greg Kroah-Hartman
2019-08-09 22:08 ` [PATCH 4.4 00/21] 4.4.189-stable review shuah
2019-08-10  4:15 ` kernelci.org bot
2019-08-10 15:45 ` Guenter Roeck
2019-08-10 16:02 ` Dan Rue
2019-08-11  7:37   ` Greg Kroah-Hartman

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