Re: [PATCH v2 2/3] riscv/purgatory: do not link with string.o and its dependencies

[Conor Dooley]

On Thu, Aug 03, 2023 at 08:13:48AM -0700, Palmer Dabbelt wrote:
> On Wed, 26 Jul 2023 09:33:49 PDT (-0700), Conor Dooley wrote:
> > On Wed, Jul 26, 2023 at 11:54:00AM +0200, Petr Tesarik wrote:
> > > From: Petr Tesarik <petr.tesarik.ext@xxxxxxxxxx>
> > > 
> > > Linking with this object file makes kexec_file_load(2) fail because of
> > > multiple unknown relocation types:
> > > 
> > > - R_RISCV_ADD16, R_RISCV_SUB16: used by alternatives in strcmp()
> > > - R_RISCV_GOT_HI20: used to resolve _ctype in strcasecmp()
> > > 
> > > All this hassle is needed for one single call to memcmp() from
> > > verify_sha256_digest() to compare 32 bytes of SHA256 checksum.
> > > 
> > > Simply replace this memcmp() call with an explicit loop over those 32 bytes
> > > and remove the need to link with string.o and all the other object files
> > > that provide undefined symbols from that object file.
> > > 
> > > Fixes: 838b3e28488f ("RISC-V: Load purgatory in kexec_file")
> > > Signed-off-by: Petr Tesarik <petr.tesarik.ext@xxxxxxxxxx>
> > 
> > This version keeps the automation happy,
> > Acked-by: Conor Dooley <conor.dooley@xxxxxxxxxxxxx>
> 
> Oddly enough, this breaks my builds.  I tried fixing the first one with
> something like

You say "tried", does that mean it also didn't work?
What's the config?

Cheers,
Conor.

> 
>    From 41c5a952f77e53bf4201296abff0132725aa19e6 Mon Sep 17 00:00:00 2001
>    From: Palmer Dabbelt <palmer@xxxxxxxxxxxx>
>    Date: Wed, 2 Aug 2023 20:22:33 -0700
>    Subject: [PATCH] RISC-V: Include io from timex
>    Without this I get some implicit declarations.
>      CC      arch/riscv/kernel/asm-offsets.s
>    In file included from linux/include/linux/timex.h:67,
>                     from linux/include/linux/time32.h:13,
>                     from linux/include/linux/time.h:60,
>                     from linux/include/linux/ktime.h:24,
>                     from linux/include/linux/timer.h:6,
>                     from linux/include/linux/workqueue.h:9,
>                     from linux/include/linux/mm_types.h:19,
>                     from linux/include/linux/mmzone.h:22,
>                     from linux/include/linux/gfp.h:7,
>                     from linux/include/linux/mm.h:7,
>                     from linux/arch/riscv/kernel/asm-offsets.c:10:
>    linux/arch/riscv/include/asm/timex.h: In function 'get_cycles':
>    linux/arch/riscv/include/asm/timex.h:25:16: error: implicit declaration of function 'readl_relaxed' [-Werror=implicit-function-declaration]
>       25 |         return readl_relaxed(((u32 *)clint_time_val));
>          |
>    Signed-off-by: Palmer Dabbelt <palmer@xxxxxxxxxxxx>
>    ---
>     arch/riscv/include/asm/timex.h | 1 +
>     1 file changed, 1 insertion(+)
>    diff --git a/arch/riscv/include/asm/timex.h b/arch/riscv/include/asm/timex.h
>    index a06697846e69..1a4d181193e0 100644
>    --- a/arch/riscv/include/asm/timex.h
>    +++ b/arch/riscv/include/asm/timex.h
>    @@ -7,6 +7,7 @@
>     #define _ASM_RISCV_TIMEX_H
>     #include <asm/csr.h>
>    +#include <asm/io.h>
>     typedef unsigned long cycles_t;
> 
>    --    2.41.0
> 
> The other two look fine and are somewhat independent, so I've picked those up
> for fixes.
> 
> Thanks!
> 
> > 
> > Thanks,
> > Conor.

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