[PATCH] riscv: Prevent early kernel panic in instrumented apply_early_boot_alternatives

[Paul Walmsley]

Hi Alex, duchangbin, Andy,

On Wed, 25 Jun 2025, duchangbin wrote:

> On Tue, Jun 24, 2025 at 02:54:32PM +0200, Alexandre Ghiti wrote:
> > Hi Changbin,
> > 
> > On 6/24/25 13:30, Changbin Du wrote:
> > > Under FTRACE=y, DYNAMIC_FTRACE=n, and RISCV_ALTERNATIVE_EARLY=n, the kernel
> > 
> > 
> > Your above config works fine for me, I guess you meant FUNCTION_TRACER &&
> > !DYNAMIC_FTRACE (which fails).
> >
> Yes, it's FUNCTION_TRACER.
> 
> > We were just talking with Andy about this configuration (FUNCTION_TRACER &&
> > !DYNAMIC_FTRACE): do we really want to support static ftrace? Andy should
> > send a patch soon to remove this possibility as IMO we don't want to support
> > it. Let's wait for this patch and the discussion that will follow before
> > merging your fix. I'll keep it in my list for 6.16 just in case someone
> > comes up with a good argument to keep it.
> > 
> No problem. I'm unable to enable DYNAMIC_FTRACE because GCC_SUPPORTS_DYNAMIC_FTRACE=n
> and CC_HAS_MIN_FUNCTION_ALIGNMENT=n are set. It seems that my GCC version (13.3.0)
> does not support the option -fmin-function-alignment=8.
> 
> By the way, this change also eliminates an empty function call.

Working on cleaning out Patchwork.  Was there any further conclusion 
reached on this patch, or more broadly, static ftrace ?


- Paul