[PATCH 4.4] x86/microcode/intel: Fix BDW late-loading revision check

[PATCH 4.4] x86/microcode/intel: Fix BDW late-loading revision check

[Ben Hutchings]

The backport of commit b94b73733171 ("x86/microcode/intel: Extend BDW
late-loading with a revision check") to 4.4-stable deleted a "return true"
statement.  This bug is not present upstream or other stable branches.

Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
---
 arch/x86/kernel/cpu/microcode/intel.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/x86/kernel/cpu/microcode/intel.c b/arch/x86/kernel/cpu/microcode/intel.c
index b428a8174be1..ee011bd7934d 100644
--- a/arch/x86/kernel/cpu/microcode/intel.c
+++ b/arch/x86/kernel/cpu/microcode/intel.c
@@ -1005,6 +1005,7 @@ static bool is_blacklisted(unsigned int cpu)
 	    c->microcode < 0x0b000021) {
 		pr_err_once("Erratum BDF90: late loading with revision < 0x0b000021 (0x%x) disabled.\n", c->microcode);
 		pr_err_once("Please consider either early loading through initrd/built-in or a potential BIOS update.\n");
+		return true;
 	}
 
 	return false;
-- 
2.15.0.rc0

Re: [PATCH 4.4] x86/microcode/intel: Fix BDW late-loading revision check

[Greg Kroah-Hartman]

On Wed, Jan 24, 2018 at 02:31:19AM +0000, Ben Hutchings wrote:
> The backport of commit b94b73733171 ("x86/microcode/intel: Extend BDW
> late-loading with a revision check") to 4.4-stable deleted a "return true"
> statement.  This bug is not present upstream or other stable branches.
> 
> Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
> ---
>  arch/x86/kernel/cpu/microcode/intel.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/arch/x86/kernel/cpu/microcode/intel.c b/arch/x86/kernel/cpu/microcode/intel.c
> index b428a8174be1..ee011bd7934d 100644
> --- a/arch/x86/kernel/cpu/microcode/intel.c
> +++ b/arch/x86/kernel/cpu/microcode/intel.c
> @@ -1005,6 +1005,7 @@ static bool is_blacklisted(unsigned int cpu)
>  	    c->microcode < 0x0b000021) {
>  		pr_err_once("Erratum BDF90: late loading with revision < 0x0b000021 (0x%x) disabled.\n", c->microcode);
>  		pr_err_once("Please consider either early loading through initrd/built-in or a potential BIOS update.\n");
> +		return true;
>  	}

That is really odd.  Thanks for catching this, now queued up.

greg k-h

Patch "x86/microcode/intel: Fix BDW late-loading revision check" has been added to the 4.4-stable tree

[gregkh]

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

    x86/microcode/intel: Fix BDW late-loading revision check

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-microcode-intel-fix-bdw-late-loading-revision-check.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 <stable@vger.kernel.org> know about it.


>From ben.hutchings@codethink.co.uk  Wed Jan 24 10:19:07 2018
From: Ben Hutchings <ben.hutchings@codethink.co.uk>
Date: Wed, 24 Jan 2018 02:31:19 +0000
Subject: x86/microcode/intel: Fix BDW late-loading revision check
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: stable@vger.kernel.org
Message-ID: <20180124023119.kaendz4jiuejowxr@xylophone.i.decadent.org.uk>
Content-Disposition: inline

From: Ben Hutchings <ben.hutchings@codethink.co.uk>

The backport of commit b94b73733171 ("x86/microcode/intel: Extend BDW
late-loading with a revision check") to 4.4-stable deleted a "return true"
statement.  This bug is not present upstream or other stable branches.

Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 arch/x86/kernel/cpu/microcode/intel.c |    1 +
 1 file changed, 1 insertion(+)

--- a/arch/x86/kernel/cpu/microcode/intel.c
+++ b/arch/x86/kernel/cpu/microcode/intel.c
@@ -1005,6 +1005,7 @@ static bool is_blacklisted(unsigned int
 	    c->microcode < 0x0b000021) {
 		pr_err_once("Erratum BDF90: late loading with revision < 0x0b000021 (0x%x) disabled.\n", c->microcode);
 		pr_err_once("Please consider either early loading through initrd/built-in or a potential BIOS update.\n");
+		return true;
 	}
 
 	return false;


Patches currently in stable-queue which might be from ben.hutchings@codethink.co.uk are

queue-4.4/x86-microcode-intel-fix-bdw-late-loading-revision-check.patch