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Date: Tue, 23 Sep 2025 08:20:59 -0400
From: Steven Rostedt <rostedt@kernel.org>
To: Peter Zijlstra <peterz@infradead.org>
Cc: linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org,
 x86@kernel.org, Masami Hiramatsu <mhiramat@kernel.org>, Mark Rutland
 <mark.rutland@arm.com>, Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
 Andrew Morton <akpm@linux-foundation.org>, Thomas Gleixner
 <tglx@linutronix.de>, Ingo Molnar <mingo@redhat.com>, Borislav Petkov
 <bp@alien8.de>, Dave Hansen <dave.hansen@linux.intel.com>, Linus Torvalds
 <torvalds@linux-foundation.org>, Josh Poimboeuf <jpoimboe@kernel.org>
Subject: Re: [PATCH v2 1/2] unwind_user/x86: Enable frame pointer unwinding
 on x86
Message-ID: <20250923082059.15fc17bc@batman.local.home>
In-Reply-To: <20250923105130.GG3419281@noisy.programming.kicks-ass.net>
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On Tue, 23 Sep 2025 12:51:30 +0200
Peter Zijlstra <peterz@infradead.org> wrote:

> Moo, and now you have me look at unwind/user.c:
> 
>         /* Make sure that the address is word aligned */
>         shift = sizeof(long) == 4 ? 2 : 3;
>         if (cfa & ((1 << shift) - 1))
>                 return -EINVAL;
> 
> Isn't that just:
> 
> 	if (cfa & (sizeof(long) - 1))
> 
> ?
> 
> Let me go add a patch to clean that up...

Sure, as long as it's commented.

Thanks,

-- Steve