On Thu, Mar 6, 2014 at 7:25 PM, Rusty Russell <rusty@xxxxxxxxxxxxxxx> wrote: > Kees Cook <keescook@xxxxxxxxxxxx> writes: >> This forces the entire per_cpu range to be reported as absolute without >> losing their linker symbol types. Without this, the variables are >> incorrectly shown as relocated under kASLR. > > I like these patches, thanks! Oh good! Glad this is getting closer. :) > This one's a bit broken, since the zero-based __per_cpu_start/end thing > is an x86-64-ism. You really do want them relocated on other > platforms, so I think you'll need do make this conditional via > a --per-cpu-absolute flag to kallsyms (which x86-64 would set). Ah, hm. Can this maybe just be dynamically detected (e.g. if __per_cpu_start == 0?), I'd hate to have another arch run into this glitch when we could "notice" it and deal with it instead. > Dumb Q: why don't we actually present these symbols as absolute in > /proc/kallsyms? Seems like it would be clearer... You mean set "sym[0] = 'A'" instead of the force_absolute thing I added? It seemed like I shouldn't mess with existing information, and as you say, they're not absolute on all platforms. -Kees -- Kees Cook Chrome OS Security -- To unsubscribe from this list: send the line "unsubscribe linux-ia64" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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