Re: [PATCH v8] kallsyms: new /proc/kallmodsyms with builtin modules

On 11 Feb 2022, Jiri Olsa verbalised:

On Tue, Feb 08, 2022 at 06:43:03PM +0000, Nick Alcock wrote:

quoted

This is all controlled by a new config parameter CONFIG_KALLMODSYMS, which when
set results in output in /proc/kallmodsyms that looks like this:

ffffffff8b013d20 409 t pt_buffer_setup_aux
ffffffff8b014130 11f T intel_pt_interrupt
ffffffff8b014250 2d T cpu_emergency_stop_pt
ffffffff8b014280 13a t rapl_pmu_event_init      [intel_rapl_perf]
ffffffff8b0143c0 bb t rapl_event_update [intel_rapl_perf]
ffffffff8b014480 10 t rapl_pmu_event_read       [intel_rapl_perf]
ffffffff8b014490 a3 t rapl_cpu_offline  [intel_rapl_perf]
ffffffff8b014540 24 t __rapl_event_show [intel_rapl_perf]
ffffffff8b014570 f2 t rapl_pmu_event_stop       [intel_rapl_perf]

hi,
I tried this version and can't see the symbols size

[root@qemu jolsa]# cat /proc/kallmodsyms | grep ksys_ | head -5
ffffffff81094720 T ksys_ioperm
ffffffff81141110 T ksys_unshare
ffffffff81160410 T ksys_setsid
ffffffff811c64b0 T ksys_sync_helper
ffffffff813213c0 T ksys_fadvise64_64

UGH, sorry, I should have regenerated the output in the cover letter!
The cover letter is buggy :)

This is entirely expected because I dropped the symbol size patch
(because it's formally unnecessary because you can do it from userspace
by examination of vmlinux or the .ko files, and the symbol size
representation is big, adding hundreds of KiB to the kernel image).
And then I failed to regenerate the output to show this :/

In this series, /proc/kallmodsyms now looks identical in format to
/proc/kallsyms, except that you can have [multiple] [modules] on a line
and the meaning of a [module] entry is different. (This may be a small
enough change in semantics that merging the two is possible, but I doubt
it -- existing users will surely expect that a [module] entry means that
module.ko exists, which with /proc/kallmodsyms is not always true.)

-- 
NULL && (void)