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Patch "x86/retpoline/checksum32: Convert assembler indirect jumps" has been added to the 4.4-stable tree

PATCH [email protected] 1 participant 1 message Jan 17, 2018

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This is a note to let you know that I've just added the patch titled

x86/retpoline/checksum32: Convert assembler indirect jumps

to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
x86-retpoline-checksum32-convert-assembler-indirect-jumps.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

Quoted 1 line

From 5096732f6f695001fa2d6f1335a2680b37912c69 Mon Sep 17 00:00:00 2001

From: David Woodhouse <[email protected]>
Date: Thu, 11 Jan 2018 21:46:32 +0000
Subject: x86/retpoline/checksum32: Convert assembler indirect jumps

From: David Woodhouse <[email protected]>

commit 5096732f6f695001fa2d6f1335a2680b37912c69 upstream.

Convert all indirect jumps in 32bit checksum assembler code to use non-speculative sequences when CONFIG_RETPOLINE is enabled.

---
 arch/x86/lib/checksum_32.S |    7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)
arch/x86/lib/checksum_32.S +4 -3
@@ -28,7 +28,8 @@
 #include <linux/linkage.h>
 #include <asm/errno.h>
 #include <asm/asm.h>
-				
+#include <asm/nospec-branch.h>
+
 /*
  * computes a partial checksum, e.g. for TCP/UDP fragments
  */
@@ -155,7 +156,7 @@ ENTRY(csum_partial)
 	negl %ebx
 	lea 45f(%ebx,%ebx,2), %ebx
 	testl %esi, %esi
-	jmp *%ebx
+	JMP_NOSPEC %ebx
 
 	# Handle 2-byte-aligned regions
 20:	addw (%esi), %ax
@@ -437,7 +438,7 @@ ENTRY(csum_partial_copy_generic)
 	andl $-32,%edx
 	lea 3f(%ebx,%ebx), %ebx
 	testl %esi, %esi 
-	jmp *%ebx
+	JMP_NOSPEC %ebx
 1:	addl $64,%esi
 	addl $64,%edi 
 	SRC(movb -32(%edx),%bl)	; SRC(movb (%edx),%bl)

Patches currently in stable-queue which might be from [email protected] are

queue-4.4/x86-spectre-add-boot-time-option-to-select-spectre-v2-mitigation.patch queue-4.4/x86-retpoline-irq32-convert-assembler-indirect-jumps.patch queue-4.4/x86-retpoline-hyperv-convert-assembler-indirect-jumps.patch queue-4.4/x86-retpoline-entry-convert-entry-assembler-indirect-jumps.patch queue-4.4/x86-cpu-amd-make-lfence-a-serializing-instruction.patch queue-4.4/x86-retpoline-ftrace-convert-ftrace-assembler-indirect-jumps.patch queue-4.4/x86-retpoline-crypto-convert-crypto-assembler-indirect-jumps.patch queue-4.4/x86-retpoline-xen-convert-xen-hypercall-indirect-jumps.patch queue-4.4/x86-retpoline-checksum32-convert-assembler-indirect-jumps.patch queue-4.4/x86-mm-32-move-setup_clear_cpu_cap-x86_feature_pcid-earlier.patch queue-4.4/x86-retpoline-fill-return-stack-buffer-on-vmexit.patch queue-4.4/x86-retpoline-remove-compile-time-warning.patch queue-4.4/x86-cpu-amd-use-lfence_rdtsc-in-preference-to-mfence_rdtsc.patch queue-4.4/x86-retpoline-add-initial-retpoline-support.patch