Re: [PATCH v4 2nd 1/4] ramoops: Add __ramoops_init_prz() as generic function

From: Mark Salyzyn
Date: Tue Feb 07 2017 - 11:07:31 EST


On 02/07/2017 12:51 AM, 岩松信洋 / IWAMATSU,NOBUHIRO wrote:
Hi,

Thanks for your review.

-----Original Message-----
From: Mark Salyzyn [mailto:salyzyn@xxxxxxxxxxx]
Sent: Friday, February 03, 2017 7:13 AM
To: 岩松信洋 / IWAMATSU,NOBUHIRO; Anton Vorontsov; Colin Cross; Kees Cook;
Tony Luck
Cc: linux-kernel@xxxxxxxxxxxxxxx; Hiraku Toyooka; 阿口誠司 / AGUCHI,
SEIJI; Shuah Khan
Subject: Re: [PATCH v4 2nd 1/4] ramoops: Add __ramoops_init_prz() as generic
function

On 01/30/2017 05:58 PM, Nobuhiro Iwamatsu wrote:
+
+ if (zap && *paddr + sz - cxt->phys_addr > cxt->size) {
+ dev_err(dev, "no room for %s mem region (0x%zx@0x%llx) in
(0x%lx@0x%llx)\n",
+ name, sz, (unsigned long long)*paddr,
+ cxt->size, (unsigned long long)cxt->phys_addr);
+ return -ENOMEM;
+ }
+
Why not allow this limit check for ramoops_init_prsz call?

This code is controlled by flag of zap.
If zap is false, __ramoops_init_prz() is worked same as original ramoops_init_przs().

Best regards,
Nobuhiro

I agree, preserve functionality as is. Please consider removing the need for zap && in a future patch, as I _believe_ (untested, and no deep dive) that the limit check is relevant for the zap is false path as well and may have been an oversight.

-- Mark