Re: Bug#1031982: bullseye-pu: package gcc-10/10.2.1-6+deb11u1

[Salvatore Bonaccorso <carnil@debian.org>]

Hi,

On Sun, Feb 26, 2023 at 11:39:02AM +0100, Salvatore Bonaccorso wrote:
> Package: release.debian.org
> Severity: normal
> Tags: bullseye
> User: release.debian.org@packages.debian.org
> Usertags: pu
> X-Debbugs-Cc: gcc-10@packages.debian.org, jmm@debian.org, doko@ubuntu.com, dianne@skoll.ca, hans@knorrie.org, 1027456@bugs.debian.org, carnil@debian.org
> Control: affects -1 + src:gcc-10
> 
> Dear stable release managers, hi Matthias,
> 
> When compiling 6.1.y kernel with gcc-10 (relevant for backports).
> It was back reported at
> https://lore.kernel.org/stable/187e8f10-2b73-3a18-d9ad-48b2d84bd6b9@pm.kalamlacki.eu/
> and in #1027456. It can be shown as well with a reduced testcase:
> 
> ----cut---------cut---------cut---------cut---------cut---------cut-----
> unsigned int
> strlen(char *s) {
>   for (; *s;)
>     ;
> }
> 
> struct i2c_adapter {
>   char name[48];
> };
> 
> struct {
>   int instance;
>   struct i2c_adapter i2c_adap[];
> } * init_cx18_i2c_cx;
> 
> const struct i2c_adapter cx18_i2c_adap_template = {""};
> int init_cx18_i2c___trans_tmp_1;
> 
> void
> init_cx18_i2c() {
>   int i = 0;
>   for (;; i++) {
>     init_cx18_i2c_cx->i2c_adap[i] = cx18_i2c_adap_template;
>     init_cx18_i2c___trans_tmp_1 = strlen(init_cx18_i2c_cx->i2c_adap[i].name);
>   }
> }
> ----cut---------cut---------cut---------cut---------cut---------cut-----
> 
> and in gcc upstream at
> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99824 .
> 
> The debdiff attached cherry-picks the upstream commit and was verified
> for both the testcase above and through Hans van Kranenburg as well
> for the kernel, in https://bugs.debian.org/1027456#61
> 
> So in order to make for bullseye-backports the 6.1.y kernel possible
> we need something to move forward.
> 
> Matthias, comments?

Is there interest in seeing this in bullseye? For the official bpo Ben
has wokarounded the entry, so the Debian backports are not directly
anymore affected by this:

https://salsa.debian.org/kernel-team/linux/-/commit/1f327c0c51ed9ca0a60c4a755feec29ffe48f0a0

But other self-compiling newer kernels might be affected.

The change was only tested against the specific case, so thus further
input is needed.

Otherwise we can as well drop this proposed update if there is not
enough confidence.

Regards,
Salvatore