Re: [PATCH v4 3/3] modversions: treat symbol CRCs as 32 bit quantities on 64 bit archs

On 19 January 2017 at 17:24, Linus Torvalds wrote: > On Thu, Jan 19, 2017 at 1:22 AM, Ard Biesheuvel > wrote: >>> >>> Your genksyms.c change is not exactly obvious. I looked at it, and my >>> brain just shut down. Why both the >>> >>>

Re: [PATCH v4 3/3] modversions: treat symbol CRCs as 32 bit quantities on 64 bit archs

On Thu, Jan 19, 2017 at 1:22 AM, Ard Biesheuvel wrote: >> >> Your genksyms.c change is not exactly obvious. I looked at it, and my >> brain just shut down. Why both the >> >> LONG(0x%08lx); >> >> _and_ the >> >> "%s__crc_%s = 0x%08lx;\n" >> >> in the linker script?

RE: [PATCH v4 3/3] modversions: treat symbol CRCs as 32 bit quantities on 64 bit archs

From: Ard Biesheuvel > Sent: 18 January 2017 13:53 .. > It turns out that this odd treatment of absolute symbols (i.e., > symbols having section number SHN_ABS) is a known issue in GNU ld > > https://sourceware.org/ml/binutils/2012-05/msg00019.html ... Jeepers - that is truly f*cked. I've even

Re: [PATCH v4 3/3] modversions: treat symbol CRCs as 32 bit quantities on 64 bit archs

On 19 January 2017 at 00:15, Linus Torvalds wrote: > On Wed, Jan 18, 2017 at 2:37 PM, Ard Biesheuvel > wrote: >> >> For a ballpark number of 10,000 CRCs in the core kernel, this would >> increase the size of the image by 40 KB for 32-bit

Re: [PATCH v4 3/3] modversions: treat symbol CRCs as 32 bit quantities on 64 bit archs

On Wed, Jan 18, 2017 at 2:37 PM, Ard Biesheuvel wrote: > > For a ballpark number of 10,000 CRCs in the core kernel, this would > increase the size of the image by 40 KB for 32-bit architectures (and > if saving 40 KB is essential, chances are you won't be using >

Re: [PATCH v4 3/3] modversions: treat symbol CRCs as 32 bit quantities on 64 bit archs

On 18 January 2017 at 18:35, Linus Torvalds wrote: > On Wed, Jan 18, 2017 at 10:27 AM, Linus Torvalds > wrote: >> >> I wonder what happened to gold, and why it didn't take over. I'm >> assuming it had _other_ bugs.. Oh well. > >

Re: [PATCH v4 3/3] modversions: treat symbol CRCs as 32 bit quantities on 64 bit archs

On Wed, Jan 18, 2017 at 10:27 AM, Linus Torvalds wrote: > > I wonder what happened to gold, and why it didn't take over. I'm > assuming it had _other_ bugs.. Oh well. Google for gold problems, I note that it has been reported to get "internal error"s during kernel

Re: [PATCH v4 3/3] modversions: treat symbol CRCs as 32 bit quantities on 64 bit archs

On Wed, Jan 18, 2017 at 5:52 AM, Ard Biesheuvel wrote: > > It turns out that this odd treatment of absolute symbols (i.e., > symbols having section number SHN_ABS) is a known issue in GNU ld > > https://sourceware.org/ml/binutils/2012-05/msg00019.html Ugh. I hate the

Re: [PATCH v4 3/3] modversions: treat symbol CRCs as 32 bit quantities on 64 bit archs

On 18 January 2017 at 11:37, Ard Biesheuvel wrote: > On 17 January 2017 at 23:47, Linus Torvalds > wrote: >> On Tue, Jan 17, 2017 at 11:26 AM, Ard Biesheuvel >> wrote: >>> The modversion symbol CRCs are emitted

Re: [PATCH v4 3/3] modversions: treat symbol CRCs as 32 bit quantities on 64 bit archs

On 17 January 2017 at 23:47, Linus Torvalds wrote: > On Tue, Jan 17, 2017 at 11:26 AM, Ard Biesheuvel > wrote: >> The modversion symbol CRCs are emitted as ELF symbols, which allows us to >> easily populate the kcrctab sections by relying

Re: [PATCH v4 3/3] modversions: treat symbol CRCs as 32 bit quantities on 64 bit archs

On Tue, Jan 17, 2017 at 11:26 AM, Ard Biesheuvel wrote: > The modversion symbol CRCs are emitted as ELF symbols, which allows us to > easily populate the kcrctab sections by relying on the linker to associate > each kcrctab slot with the correct value. > > This has a