Messages in this thread | | | Date | Sun, 28 May 2023 14:12:24 +0100 | From | Conor Dooley <> | Subject | Re: [PATCH -fixes] riscv: Fix relocatable kernels with early alternatives using -fno-pie |
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On Sun, May 28, 2023 at 03:00:57PM +0200, Alexandre Ghiti wrote: > On Sat, May 27, 2023 at 12:02 PM Conor Dooley <conor@kernel.org> wrote: > > > > On Sat, May 27, 2023 at 11:13:18AM +0200, Alexandre Ghiti wrote: > > > > > > On 26/05/2023 18:35, Conor Dooley wrote: > > > > On Fri, May 26, 2023 at 05:24:41PM +0100, Conor Dooley wrote: > > > > > On Fri, May 26, 2023 at 05:46:30PM +0200, Alexandre Ghiti wrote: > > > > > > Early alternatives are called with the mmu disabled, and then should not > > > > > > access any global symbols through the GOT since it requires relocations, > > > > > > relocations that we do before but *virtually*. So only use medany code > > > > > > model for this early code. > > > > > > > > > > > > Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com> > > > > > > --- > > > > > > > > > > > > Note that I'm not very happy with this fix, I think we need to put more > > > > > > effort into "harmonizing" this very early code (ie before the mmu is > > > > > > enabled) as it is spread between different locations and compiled > > > > > > differently. > > > > > Totally & I'll happily spend the time trying to review that work. > > > > > > > > > > > I'll work on that later, but for now, this fix does what is > > > > > > needed to work (from my testing at least). Any Tested-by on the Unmatched > > > > > > and T-head boards is welcome! > > > > > On 6.4-rc1 & v6.4-rc1 + this patch, with CONFIG_RELOCATABLE added to my > > > > > config, my Nezha fails to boot. There is no output whatsoever from the > > > > > kernel. Turning off CONFIG_RELOCATABLE boots again. > > > > I don't know if this is better or worse news, but same thing happens on > > > > an icicle kit. What systems, other than QEMU, has the relocatable > > > > eries been tested with, btw? > > > > > > > > > I tested it on the Unmatched (Andreas did too). > > > > Cool. I cracked out my unmatched and it has the same issue as the > > icicle. Ditto my Visionfive v2. Here's my config. > > https://raw.githubusercontent.com/ConchuOD/riscv-env/dev/conf/defconfig > > > > A ~default qemu virt doesn't work either. (-m 2G -smp 5) > > I can boot with this config using: > > $ sudo ~/qemu/build/qemu-system-riscv64 -machine virt -cpu > rv64,sv48=off -nographic -m 2G -smp 5 -kernel > build_conor/arch/riscv/boot/Image -s
Just in case, that is my normal config that I use for testing random stuff on LKML, I added CONFIG_RELOCATABLE in addition to that.
> I noticed when trying to add this to our internal CI that I had local > failures that did not happen in the CI because the CI was not using > the same toolchain: can you give me the full .config? So that I can > see if the compiler added stack guards or some other things I did not > think of.
https://gist.githubusercontent.com/ConchuOD/655f9cc19fb3be63f1c9da7e7e3ab717/raw/a1aad3c0d307609b2062fd3a66705166aede9f9f/.config
90% of what I test for upstream stuff uses clang, since clang appears to be a minority choice - but I could reproduce this with gcc-12 as well, using the same defconfig as linked above + CONFIG_RELOCATABLE.
Cheers, Conor. [unhandled content-type:application/pgp-signature] | |