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authorAwais Belal <awais_belal@mentor.com>2018-05-10 14:12:22 +0500
committerAwais Belal <awais_belal@mentor.com>2018-05-10 14:37:34 +0500
commite5c5c71d216971220499a44de3f51c091f1ac049 (patch)
treebc74d0e18805385faed29f765b08b2a0e6b3f1f7 /common/recipes-kernel/linux/linux-yocto-4.9.21/0059-x86-alternatives-Fix-optimize_nops-checking.patch
parentdd06f966521a022d5ca7365859a9e0151b6945d0 (diff)
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linux-yocto/4.9: fix bpf backports for spectre/meltdown
A commit was missed during backports which generates failure during build. This now picks that commit up as well and updates the series appropriately. Signed-off-by: Awais Belal <awais_belal@mentor.com>
Diffstat (limited to 'common/recipes-kernel/linux/linux-yocto-4.9.21/0059-x86-alternatives-Fix-optimize_nops-checking.patch')
-rw-r--r--common/recipes-kernel/linux/linux-yocto-4.9.21/0059-x86-alternatives-Fix-optimize_nops-checking.patch56
1 files changed, 56 insertions, 0 deletions
diff --git a/common/recipes-kernel/linux/linux-yocto-4.9.21/0059-x86-alternatives-Fix-optimize_nops-checking.patch b/common/recipes-kernel/linux/linux-yocto-4.9.21/0059-x86-alternatives-Fix-optimize_nops-checking.patch
new file mode 100644
index 00000000..b954c23c
--- /dev/null
+++ b/common/recipes-kernel/linux/linux-yocto-4.9.21/0059-x86-alternatives-Fix-optimize_nops-checking.patch
@@ -0,0 +1,56 @@
+From 1ac5fc23c160f82956aa23fd595206a15d80d742 Mon Sep 17 00:00:00 2001
+From: Borislav Petkov <bp@suse.de>
+Date: Wed, 10 Jan 2018 12:28:16 +0100
+Subject: [PATCH 059/103] x86/alternatives: Fix optimize_nops() checking
+
+commit 612e8e9350fd19cae6900cf36ea0c6892d1a0dca upstream.
+
+The alternatives code checks only the first byte whether it is a NOP, but
+with NOPs in front of the payload and having actual instructions after it
+breaks the "optimized' test.
+
+Make sure to scan all bytes before deciding to optimize the NOPs in there.
+
+Reported-by: David Woodhouse <dwmw2@infradead.org>
+Signed-off-by: Borislav Petkov <bp@suse.de>
+Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
+Cc: Tom Lendacky <thomas.lendacky@amd.com>
+Cc: Andi Kleen <ak@linux.intel.com>
+Cc: Tim Chen <tim.c.chen@linux.intel.com>
+Cc: Peter Zijlstra <peterz@infradead.org>
+Cc: Jiri Kosina <jikos@kernel.org>
+Cc: Dave Hansen <dave.hansen@intel.com>
+Cc: Andi Kleen <andi@firstfloor.org>
+Cc: Andrew Lutomirski <luto@kernel.org>
+Cc: Linus Torvalds <torvalds@linux-foundation.org>
+Cc: Greg Kroah-Hartman <gregkh@linux-foundation.org>
+Cc: Paul Turner <pjt@google.com>
+Link: https://lkml.kernel.org/r/20180110112815.mgciyf5acwacphkq@pd.tnic
+Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ arch/x86/kernel/alternative.c | 7 +++++--
+ 1 file changed, 5 insertions(+), 2 deletions(-)
+
+diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c
+index 5cb272a..10d5a3d 100644
+--- a/arch/x86/kernel/alternative.c
++++ b/arch/x86/kernel/alternative.c
+@@ -340,9 +340,12 @@ recompute_jump(struct alt_instr *a, u8 *orig_insn, u8 *repl_insn, u8 *insnbuf)
+ static void __init_or_module optimize_nops(struct alt_instr *a, u8 *instr)
+ {
+ unsigned long flags;
++ int i;
+
+- if (instr[0] != 0x90)
+- return;
++ for (i = 0; i < a->padlen; i++) {
++ if (instr[i] != 0x90)
++ return;
++ }
+
+ local_irq_save(flags);
+ add_nops(instr + (a->instrlen - a->padlen), a->padlen);
+--
+2.7.4
+