size in /proc/modules

size in /proc/modules

[John Levon]

/proc/modules size field includes init_size in 2.5. Why ?

The removal of sensible values in /proc/ksyms means that oprofile can no
longer attribute module samples reliably. The only information we have
is module_core address, and size == core_size+init_size. Since init code
is removed in sys_init_module, this will overestimate, and can lead to
overlapping with the start of another module, afaics.

In 2.4, we had size(.text), which could underestimate (think
.text.exit), but that is not a big problem.

Rusty, does this fall under another one of your "corner cases" ? (what I
would call "flaky code" ...)

Or I have I just missed something obvious ?

regards
john

-- 
"Anyone who quotes Rusty in their sig is an idiot."
	- me

Re: size in /proc/modules

[Rusty Russell]

In message <20030120142703.GA58326@compsoc.man.ac.uk> you write:
> 
> /proc/modules size field includes init_size in 2.5. Why ?
> 
> The removal of sensible values in /proc/ksyms means that oprofile can no
> longer attribute module samples reliably. The only information we have
> is module_core address, and size == core_size+init_size. Since init code
> is removed in sys_init_module, this will overestimate, and can lead to
> overlapping with the start of another module, afaics.
> 
> In 2.4, we had size(.text), which could underestimate (think
> .text.exit), but that is not a big problem.
> 
> Rusty, does this fall under another one of your "corner cases" ? (what I
> would call "flaky code" ...)
> 
> Or I have I just missed something obvious ?

Yes, line 1328 of kernel/module.c, by the sound of it 8)

I was thinking of you when I added this, actually.

Hope that helps!
Rusty.
--
  Anyone who quotes me in their sig is an idiot. -- Rusty Russell.