lkml.org 
[lkml]   [2023]   [Jun]   [26]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCH v2] perf unwind: Fix map reference counts
    On Fri, Jun 23, 2023 at 10:49:36AM -0700, Ian Rogers wrote:
    > >
    > > How do you think about to add the tag “Fixes”?
    >
    > In general we've not been adding Fixes as there is a danger a backport
    > will introduce a use-after-free.

    I feel like we have been discussing issues around Perf backports
    recently. Wasn't there some build breakage that wasn't detected? Why
    not just ask Sasha to leave perf out of the -stable tree?

    Also Sasha has a tag to explain that patch AAA is included because
    patch BBB depends on it. I feel like maybe those tags are backwards,
    it would be nicer to tag AAA as depending on BBB. That way we could
    add the dependency tags here.

    I think at Linaro we have recently been testing taking the latest Perf
    tools and using them on older kernels. I don't know the details around
    why we can't just use the perf that ships with the kernel...

    To tell the truth, I also don't really understand the problem for this
    patch specifically. From what I can see, the Fixes tag would have been:

    Fixes: 0dd5041c9a0e ("perf addr_location: Add init/exit/copy functions")

    1) Adding a Fixes tag would have automatically prevented any backports.
    2) I don't see any possible use after frees. That probably means I have
    identified the wrong Fixes tag?

    I'm not going to dig further than that because I don't care. I'm just
    looking at it because Markus added kernel-janitors to the CC list. But
    for subsystems where I'm more involved then I always look at how a bug
    is introduced. That information is essential to me as a reviewer. So
    if I'm writing a patch and even if it's not a bug fix but let's say it
    deletes dead code then I often include include the information under the
    --- cut off line.

    ---
    This dead code was introduced by commit 23423423 ("blah blah blah").

    regards,
    dan carpenter

    \
     
     \ /
      Last update: 2023-06-26 14:42    [W:3.803 / U:0.008 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site