<p></p>
<blockquote>
<blockquote>
<blockquote>
<pre><code>regs->orig_a0 = regs->regs[4];
regs->regs[4] = -ENOSYS;
nr = syscall_enter_from_user_mode(regs, nr);
</code></pre>
</blockquote>
<p dir="auto">This way the first syscall argument won't be available for ptracers because <code>regs->orig_a0</code> is not exposed in <code>struct user_pt_regs</code> and not handled by <code>gpr_get</code> and <code>gpr_set</code>.</p>
</blockquote>
<p dir="auto">Hmm, can we keep do_syscall() as is and solve the ptrace problem by overriding arch_syscall_enter_tracehook() like this?</p>
<p dir="auto">static inline __must_check int arch_syscall_enter_tracehook(struct pt_regs *regs) {</p>
<pre><code>    ret = tracehook_report_syscall_entry(regs);

    if (ret)
            syscall_set_return_value(current, current_pt_regs(), -ENOSYS, 0);

    return ret;
</code></pre>
<p dir="auto">}</p>
</blockquote>
<p dir="auto">Hi <a class="user-mention" data-hovercard-type="user" data-hovercard-url="/users/chenhuacai/hovercard" data-octo-click="hovercard-link-click" data-octo-dimensions="link_type:self" href="https://github.com/chenhuacai">@chenhuacai</a>, I tried in <a href="https://github.com/xen0n/linux/commit/d748c0a67619f77128f46ecd392fbc9f0686bcbe">this commit</a> and confirmed it's not working; exactly the same failures as before.</p>

<p style="font-size:small;-webkit-text-size-adjust:none;color:#666;">—<br />Reply to this email directly, <a href="https://github.com/strace/strace/pull/205#issuecomment-1008044511">view it on GitHub</a>, or <a href="https://github.com/notifications/unsubscribe-auth/AOVBTR6FUBNNBDOPXHRMLL3UVBO5LANCNFSM5KYUVD5Q">unsubscribe</a>.<br />Triage notifications on the go with GitHub Mobile for <a href="https://apps.apple.com/app/apple-store/id1477376905?ct=notification-email&mt=8&pt=524675">iOS</a> or <a href="https://play.google.com/store/apps/details?id=com.github.android&referrer=utm_campaign%3Dnotification-email%26utm_medium%3Demail%26utm_source%3Dgithub">Android</a>.
<br />You are receiving this because you are subscribed to this thread.<img src="https://github.com/notifications/beacon/AOVBTR5EGR7AWQAPEKE4DY3UVBO5LA5CNFSM5KYUVD52YY3PNVWWK3TUL52HS4DFVREXG43VMVBW63LNMVXHJKTDN5WW2ZLOORPWSZGOHQKYTXY.gif" height="1" width="1" alt="" /><span style="color: transparent; font-size: 0; display: none; visibility: hidden; overflow: hidden; opacity: 0; width: 0; height: 0; max-width: 0; max-height: 0; mso-hide: all">Message ID: <span><strace/strace/pull/205/c1008044511</span><span>@</span><span>github</span><span>.</span><span>com></span></span></p>
<script type="application/ld+json">[
{
"@context": "http://schema.org",
"@type": "EmailMessage",
"potentialAction": {
"@type": "ViewAction",
"target": "https://github.com/strace/strace/pull/205#issuecomment-1008044511",
"url": "https://github.com/strace/strace/pull/205#issuecomment-1008044511",
"name": "View Pull Request"
},
"description": "View this Pull Request on GitHub",
"publisher": {
"@type": "Organization",
"name": "GitHub",
"url": "https://github.com"
}
}
]</script>