Re: [PATCH v10 3/4] console: Add persistent scrollback buffers for all VGA consoles
From: Adam Borowski <hidden>
Date: 2017-01-19 23:44:19
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On Thu, Jan 19, 2017 at 05:33:14PM +0100, Greg KH wrote:
On Thu, Jan 19, 2017 at 05:12:15PM +0100, Manuel Schölling wrote:quoted
On Thu, 2017-01-19 at 14:23 +0100, Greg KH wrote:quoted
On Fri, Jan 13, 2017 at 09:07:57PM +0100, Manuel Schölling wrote:quoted
+ This feature might break your tool of choice to flush the scrollback + buffer, e.g. clear(1) will work fine but Debian's clear_console(1) + will be broken, which might cause security issues. + You can use the escape sequence \e[3J instead if this feature is + activated.This issue is the one that makes me the most worried. Why doesn't clear_console() work anymore? Why doesn't it use \e[3J ?Well, clear_console() just switches from one console to another and back again. It just assumes that the scrollback buffer is flushed when switching. My plan is to make a patch for clear_console() as soon as these patches are in the kernel - it's chicken-and-egg problem.I'd recommend that patch get to clear_console() first, having it use the new escape sequence, if it isn't supported, shouldn't cause any problems, right?
In that case, we need to hurry -- the last day for any non-serious fixes in Debian is Jan 26, after that it'll be frozen for months, and any subsequent changes won't get to stable users for around two years. doko: would you consider, pretty please with a cherry on top, applying the patch I've sent to this bug? The privacy/security issue is pretty minor and applies only to a tiny fraction of users, but I understand why Greg is reluctant. Manuel's scrollback changes won't go to 4.9, and won't be enabled by default for the time being, but using a newer kernel on old userspace is something really widespread, be it via bpo, containers on an updated host, etc. Meow! -- Autotools hint: to do a zx-spectrum build on a pdp11 host, type: ./configure --host=zx-spectrum --build=pdp11