Messages in this thread | | | Date | Fri, 6 Jun 2014 13:45:14 -0700 | Subject | Re: "." in vmlinux.lds.S | From | Hán Shěn (沈涵) <> |
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Hi Andy, this changes "Ndx" field for the symbol. For example, one of the symbol '__end_rodata_hpage_align' in symtab, the contents changed from 50206: ffffffff81800000 0 NOTYPE GLOBAL DEFAULT ABS __end_rodata_hpage_align which is correct, to 50206: ffffffff81800000 0 NOTYPE GLOBAL DEFAULT 25 __end_rodata_hpage_align (25 is the index to section '.data') which is wrong.
Han
On Fri, Jun 6, 2014 at 12:08 PM, Andy Lutomirski <luto@amacapital.net> wrote: > On Fri, Jun 6, 2014 at 11:53 AM, Hán Shěn (沈涵) <shenhan@google.com> wrote: >> Yeah, the symbol "__end_rodata_hpage_align" is defined as absolute in >> older binutils, the newer binutils making it relative seems >> meaningless in this context. > > What I mean is: what actually changes in the linker output when the > symbol is relative? > > --Andy > >> >> On Fri, Jun 6, 2014 at 11:40 AM, Andy Lutomirski <luto@amacapital.net> wrote: >>> On 06/06/2014 10:08 AM, Hán Shěn (沈涵) wrote: >>>> A gentle ping? >>>> >>>> On Tue, Jun 3, 2014 at 2:46 PM, Hán Shěn (沈涵) <shenhan@google.com> wrote: >>>>> Hi we are trying to boot up a x86_64 chrome book using binutils 2.24 and >>>>> kernel 3.8, but failed. >>>>> >>>>> After some triage work, we found that a 2-year-old binutil CL changed the >>>>> interpretation of "." in linker script (short story: absolute -> relative, >>>>> long story: https://sourceware.org/ml/binutils/2012-06/msg00155.html). >>>>> >>>>> After some further work, we are able to boot the kernel with a kernel patch >>>>> pasted at EOM. I am curious, why the upstream kernel is never hit by this >>>>> behavior? We enabled "CONFIG_DEBUG_RODATA", so we were hit, is this some >>>>> macro not usually turned on? >>> >>> What does a section-relative symbol do? >>> >>> --Andy >> >> >> >> -- >> Han Shen | Software Engineer | shenhan@google.com | +1-650-440-3330 > > > > -- > Andy Lutomirski > AMA Capital Management, LLC
-- Han Shen | Software Engineer | shenhan@google.com | +1-650-440-3330 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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