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Date: Thu, 26 Feb 2026 03:15:17 -0500
To: KENNON J CONRAD <kennonconrad@comcast.net>
Cc: KENNON J CONRAD via Cygwin <cygwin@cygwin.com>
Subject: Re: Memmove causing program crashes, giving SIGTRAP in GDB(?)
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From: Glenn Strauss via Cygwin <cygwin@cygwin.com>
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On Wed, Feb 25, 2026 at 11:59:07PM -0800, KENNON J CONRAD via Cygwin wrote:
> Okay, so now I learned about setting the frame and disassemble and see the memmove code:
> 
> Dump of assembler code for function memmove:
[snip]
> => 0x00007ff96ba812a9 <+137>:	rep movsq %ds:(%rsi),%es:(%rdi)
[snip]
> End of assembler dump.

movsq requires address alignment of 8 bytes.
What are the pointer addresses of the arguments to memmove()?
A SIGTRAP may result if the addresses are not 8-byte aligned.

Cheers, Glenn

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