lkml.org 
[lkml]   [2021]   [Jun]   [9]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] kallsyms: fix nonconverging kallsyms table with lld
Hi Arnd,

On Thu, Feb 04, 2021 at 04:29:47PM +0100, Arnd Bergmann wrote:
> From: Arnd Bergmann <arnd@arndb.de>
>
> ARM randconfig builds with lld sometimes show a build failure
> from kallsyms:
>
> Inconsistent kallsyms data
> Try make KALLSYMS_EXTRA_PASS=1 as a workaround
>
> The problem is the veneers/thunks getting added by the linker extend
> the symbol table, which in turn leads to more veneers being needed,
> so it may take a few extra iterations to converge.
>
> This bug has been fixed multiple times before, but comes back every time
> a new symbol name is used. lld uses a different set of idenitifiers from
> ld.bfd, so the additional ones need to be added as well.
>
> I looked through the sources and found that arm64 and mips define similar
> prefixes, so I'm adding those as well, aside from the ones I observed. I'm
> not sure about powerpc64, which seems to already be handled through a
> section match, but if it comes back, the "__long_branch_" and "__plt_"
> prefixes would have to get added as well.
>

This is such a whack-a-mole. The problem is hitting us yet again. I suspect
it may be due to a new version of lld using new symbols, but I didn't really
try to track it down. Is there an easy way to search for missed symbols ?

In this context .. is there a chance to apply [1] after all ? This is getting
really time consuming and annoying, and I really dislike having to fix the same
problem over and over again.

Thanks,
Guenter

---
[1] https://patchwork.kernel.org/project/linux-kbuild/patch/20200910153204.156871-1-linux@roeck-us.net/

\
 
 \ /
  Last update: 2021-06-09 13:05    [W:0.101 / U:0.028 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site