linux-kernel - Re: [PATCH V15 03/11] cper: add timestamp print to CPER status printing

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Fri, 21 Apr 2017 19:26:03 +0200
From:   Borislav Petkov <bp@...en8.de>
To:     "Baicar, Tyler" <tbaicar@...eaurora.org>
Cc:     christoffer.dall@...aro.org, marc.zyngier@....com,
        pbonzini@...hat.com, rkrcmar@...hat.com, linux@...linux.org.uk,
        catalin.marinas@....com, will.deacon@....com, rjw@...ysocki.net,
        lenb@...nel.org, matt@...eblueprint.co.uk, robert.moore@...el.com,
        lv.zheng@...el.com, nkaje@...eaurora.org, zjzhang@...eaurora.org,
        mark.rutland@....com, james.morse@....com,
        akpm@...ux-foundation.org, eun.taik.lee@...sung.com,
        sandeepa.s.prabhu@...il.com, labbott@...hat.com,
        shijie.huang@....com, rruigrok@...eaurora.org,
        paul.gortmaker@...driver.com, tn@...ihalf.com, fu.wei@...aro.org,
        rostedt@...dmis.org, bristot@...hat.com,
        linux-arm-kernel@...ts.infradead.org, kvmarm@...ts.cs.columbia.edu,
        kvm@...r.kernel.org, linux-kernel@...r.kernel.org,
        linux-acpi@...r.kernel.org, linux-efi@...r.kernel.org,
        devel@...ica.org, Suzuki.Poulose@....com, punit.agrawal@....com,
        astone@...hat.com, harba@...eaurora.org, hanjun.guo@...aro.org,
        john.garry@...wei.com, shiju.jose@...wei.com, joe@...ches.com,
        rafael@...nel.org, tony.luck@...el.com, gengdongjiu@...wei.com,
        xiexiuqi@...wei.com
Subject: Re: [PATCH V15 03/11] cper: add timestamp print to CPER status
 printing

On Fri, Apr 21, 2017 at 10:04:35AM -0600, Baicar, Tyler wrote:
> This is basically what I already had in v14...you asked to move it into a
> different if-statement? https://lkml.org/lkml/2017/4/12/397

Well, clearly I've been smoking some nasty potent sh*t. :-\

/me goes and looks at the spec:

"Bit 0 – Timestamp is precise if this bit is set and correlates to the
time of the error event."

So why are we even printing the timestamp when !precise?

IOW, I think we should do:

	if (!(timestamp[3] & 0x1))
		printk("%stimestamp imprecise\n", pfx);
	else {
		sec = ..
		min = ...

		...
	}

and print the actual values only when the timestamp is precise.
Otherwise it has *some* values which could just as well be completely
random. And it's not like we're reporting the error tomorrow - it is
mostly a couple of seconds from logging to the fw pushing it out...

-- 
Regards/Gruss,
    Boris.

Good mailing practices for 400: avoid top-posting and trim the reply.