Messages in this thread | | | From | Joel Stanley <> | Date | Mon, 28 Mar 2022 22:31:40 +0000 | Subject | Re: [PATCH] recordmcount: Support empty section from recent binutils |
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On Mon, 29 Nov 2021 at 22:43, Christophe Leroy <christophe.leroy@csgroup.eu> wrote: > > > > Le 29/11/2021 à 18:43, Steven Rostedt a écrit : > > On Fri, 26 Nov 2021 08:43:23 +0000 > > LEROY Christophe <christophe.leroy@csgroup.eu> wrote: > > > >> Le 24/11/2021 à 15:43, Christophe Leroy a écrit : > >>> Looks like recent binutils (2.36 and over ?) may empty some section, > >>> leading to failure like: > >>> > >>> Cannot find symbol for section 11: .text.unlikely. > >>> kernel/kexec_file.o: failed > >>> make[1]: *** [scripts/Makefile.build:287: kernel/kexec_file.o] Error 1 > >>> > >>> In order to avoid that, ensure that the section has a content before > >>> returning it's name in has_rel_mcount(). > >> > >> This patch doesn't work, on PPC32 I get the following message with this > >> patch applied: > >> > >> [ 0.000000] ftrace: No functions to be traced? > >> > >> Without the patch I get: > >> > >> [ 0.000000] ftrace: allocating 22381 entries in 66 pages > >> [ 0.000000] ftrace: allocated 66 pages with 2 groups > > > > Because of this report, I have not applied this patch (even though I was > > about to push it to Linus). > > > > I'm pulling it from my queue until this gets resolved. > > > > I have no idea on how to fix that for the moment. > > With GCC 10 (binutils 2.36) an objdump -x on kernel/kexec_file.o gives: > > 0000000000000000 l d .text.unlikely 0000000000000000 .text.unlikely > 0000000000000000 w F .text.unlikely 0000000000000038 > .arch_kexec_apply_relocations_add > 0000000000000038 w F .text.unlikely 0000000000000038 > .arch_kexec_apply_relocations > > > With GCC 11 (binutils 2.37) the same gives: > > 0000000000000000 w F .text.unlikely 0000000000000038 > .arch_kexec_apply_relocations_add > 0000000000000038 w F .text.unlikely 0000000000000038 > .arch_kexec_apply_relocations > > > The problem is that recordmcount drops weak symbols, and it doesn't find > any non-weak symbol in .text.unlikely > > Explication given at > https://elixir.bootlin.com/linux/v5.16-rc2/source/scripts/recordmcount.h#L506 > > I have no idea on what to do.
Did you end up finding a solution for this issue?
Cheers,
Joel
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