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Date:   Fri, 15 Oct 2021 22:10:14 +0900
From:   Masami Hiramatsu <mhiramat@kernel.org>
To:     Masami Hiramatsu <mhiramat@kernel.org>
Cc:     Steven Rostedt <rostedt@goodmis.org>,
        "Naveen N . Rao" <naveen.n.rao@linux.vnet.ibm.com>,
        Ananth N Mavinakayanahalli <ananth@linux.ibm.com>,
        Ingo Molnar <mingo@kernel.org>, linux-kernel@vger.kernel.org,
        Sven Schnelle <svens@linux.ibm.com>,
        Catalin Marinas <catalin.marinas@arm.com>,
        Will Deacon <will@kernel.org>,
        Russell King <linux@armlinux.org.uk>,
        Nathan Chancellor <nathan@kernel.org>,
        Nick Desaulniers <ndesaulniers@google.com>,
        linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH 03/10] x86/unwind: Compile kretprobe fixup code only if
 CONFIG_KRETPROBES=y
Message-Id: <20211015221014.5be86007034a5ed9356848b3@kernel.org>
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On Fri, 15 Oct 2021 21:51:10 +0900
Masami Hiramatsu <mhiramat@kernel.org> wrote:

> Compile kretprobe related stacktrace entry recovery code and
> unwind_state::kr_cur field only when CONFIG_KRETPROBES=y.

Oh, this is another new patch, and is a kind of cleanup.
No functionality change, but a bit reducing memory usage
when CONFIG_KRETPROBES=n.

Thank you,

> 
> Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
> ---
>  arch/x86/include/asm/unwind.h |    6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/arch/x86/include/asm/unwind.h b/arch/x86/include/asm/unwind.h
> index fca2e783e3ce..2a1f8734416d 100644
> --- a/arch/x86/include/asm/unwind.h
> +++ b/arch/x86/include/asm/unwind.h
> @@ -16,7 +16,9 @@ struct unwind_state {
>  	unsigned long stack_mask;
>  	struct task_struct *task;
>  	int graph_idx;
> +#ifdef CONFIG_KRETPROBES
>  	struct llist_node *kr_cur;
> +#endif
>  	bool error;
>  #if defined(CONFIG_UNWINDER_ORC)
>  	bool signal, full_regs;
> @@ -105,9 +107,13 @@ static inline
>  unsigned long unwind_recover_kretprobe(struct unwind_state *state,
>  				       unsigned long addr, unsigned long *addr_p)
>  {
> +#ifdef CONFIG_KRETPROBES
>  	return is_kretprobe_trampoline(addr) ?
>  		kretprobe_find_ret_addr(state->task, addr_p, &state->kr_cur) :
>  		addr;
> +#else
> +	return addr;
> +#endif
>  }
>  
>  /* Recover the return address modified by kretprobe and ftrace_graph. */
> 


-- 
Masami Hiramatsu <mhiramat@kernel.org>