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<div style="LINE-HEIGHT: 15pt">Thanks Valdis,</div>
<div style="LINE-HEIGHT: 15pt">I thought similar way and it's clearer. Probably bit 0 of the sys_call_table contains whether it's using fast syscal.</div>
<div style="LINE-HEIGHT: 15pt">But I couldn't find the code setting bit 0. I'll try later when I'm done with more urgent things.</div>
<div style="LINE-HEIGHT: 15pt">Thank you!</div>
<div style="LINE-HEIGHT: 15pt">Chan<br>
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<div style="LINE-HEIGHT: 15pt"><b>From : </b>"Valdis.Kletnieks@vt.edu" <Valdis.Kletnieks@vt.edu><br>
<b>Sent : </b>2014-03-28 22:36:27 ( +09:00 )<br>
<b>To : </b>Chan Kim <ckim@etri.re.kr><br>
<b>Cc : </b>kernelnewbies@kernelnewbies.org <kernelnewbies@kernelnewbies.org><br>
<b>Subject : </b>Re: in sparc linux system call entry assembly code<br>
<br>
On Fri, 28 Mar 2014 07:25:37 -0000, 김찬 said:<br>
> andcc %l7, 1, %g0<br>
> bne linux_fast_syscall<br>
<br>
> Then what is this "andcc %l7, 1, %g0" doing?<br>
<br>
Well, I'm not an expert on Sparc assembler, but.. 'andcc' looks like it's<br>
doing an and, and setting the cc (condition code). Then 'bne' branch not<br>
equal. Looks to me like it's testing a bit in the just-loaded address<br>
to see if it's flagged as using the fast_syscall code. Go check the code<br>
that generates the table and see if there is something different about the<br>
way they generate some entries.<br>
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