Re: [PATCH v3 5/8] riscv: stacktrace: introduce stack-bound tracking helpers

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Low] The new `stackinfo_get_irq()` helper will cause a linker error when wired up if `CONFIG_IRQ_STACKS` is disabled.
--

commit 106252794f147e577df13bf90a54471b531228ae
Author: Wang Han <wanghan@linux.alibaba.com>

riscv: stacktrace: introduce stack-bound tracking helpers

This commit introduces the necessary building blocks for a robust frame-pointer
unwinder on RISC-V. It adds stack boundary tracking and accessors for
different stack types (IRQ, task, overflow) to ensure the unwinder stays
within known, valid bounds.

> diff --git a/arch/riscv/include/asm/stacktrace.h b/arch/riscv/include/asm/stacktrace.h
> index b1495a7e06ce6..bc87c49403798 100644
> --- a/arch/riscv/include/asm/stacktrace.h
> +++ b/arch/riscv/include/asm/stacktrace.h

[ ... ]

> -static inline bool on_thread_stack(void)
> +/*
> + * IRQ stack accessors
> + */
> +static inline struct stack_info stackinfo_get_irq(void)
> +{
> +	unsigned long low = (unsigned long)raw_cpu_read(irq_stack_ptr);

[Severity: Low]
Does this cause a linker error when CONFIG_IRQ_STACKS is disabled?

This function unconditionally references irq_stack_ptr, but the definition of
irq_stack_ptr in arch/riscv/kernel/irq.c is guarded by CONFIG_IRQ_STACKS.
If CONFIG_IRQ_STACKS is disabled (which is possible if CONFIG_EXPERT=y), and 
the unwinder unconditionally evaluates this accessor to add the IRQ stack to 
its stack list, will this lead to an "undefined reference to 'irq_stack_ptr'" 
during linking?

> +	unsigned long high = low + IRQ_STACK_SIZE;
> +
> +	return (struct stack_info) {
> +		.low = low,
> +		.high = high,
> +	};
> +}

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/cover.194d76e3a15b.v3.riscv-livepatch.wanghan@linux.alibaba.com?part=5