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copied!<p>After some web searching, I landed to this other topic on StackOverflow: <a href="https://stackoverflow.com/questions/13595033/linux-invoke-a-system-call-via-sysenter-tutorial">Linux invoke a system call via sysenter tutorial</a>. It says the recommended way to invoke the system, is neither using <code>int 80h</code> nor <code>syscall</code> nor <code>sysenter</code>, but <code>linux-gate.so</code>.</p> <p>Still remains the question about the crash and core‑dump. My guess is finally that although either <code>syscall</code> or <code>sysenter</code> instructions are available as a CPU instruction, may be the Linux kernel just does not set‑up properly this “entry point” when it decide it's not really useful on a given hardware platform.</p> <p>Seems on 32 bits platform, <code>sysenter</code> or <code>syscall</code> <strong>may</strong> be available, while it's always available, only on 64 bits platform.</p> <p>Although I feel this answer my question, I still welcome more material, like an authoritative reference for my above guess.</p> <p>-- update --</p> <p>At least, I could find this which confirm the above. That's still not an authoritative reference but seems trustable enough I believe.</p> <p><a href="http://www.trilithium.com/johan/2005/08/linux-gate/" rel="nofollow noreferrer">What is linux-gate.so.1?</a>, says:</p> <blockquote> <p>The preferred way of invoking a system call is <strong>determined by the kernel at boot time</strong>, and evidently this box uses sysenter.</p> </blockquote> <p>Also, from another source, a sample FASM assembly source (needs some translations if you use NASM), to call a system function via <code>linux-gate.so</code>: <a href="http://shaurz.wordpress.com/2008/06/02/finding-linux-gateso1-in-assembly/" rel="nofollow noreferrer">Finding linux-gate.so.1 in Assembly </a>.</p>

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