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Date: Fri, 23 Jan 2026 17:18:20 -0800
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Subject: Re: [PATCH v1 0/2] selftests/x86: Skip int80 if not supported
To: =?UTF-8?Q?S=C5=82awomir_Rosek?= <srosek@google.com>,
        Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@redhat.com>,
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        Dave Hansen <dave.hansen@linux.intel.com>, x86@kernel.org,
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        Alistair Delva <adelva@google.com>, linux-kernel@vger.kernel.org,
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References: <20251217135932.3153847-1-srosek@google.com>
 <CAF3aWvHbSgDYxgFHF05FkEGQncMUXsuwMPDBCcoXUGoQgESuEg@mail.gmail.com>
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From: "H. Peter Anvin" <hpa@zytor.com>
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On 2026-01-12 03:23, Sławomir Rosek wrote:
> On Wed, Dec 17, 2025 at 2:59 PM Slawomir Rosek <srosek@google.com> wrote:
>>
>> The IA32 Emulation support can be either removed from the kernel,
>> disabled by default or disabled at runtime. Some of x86 selftests
>> are crashing for all of above thus is_32bit_syscall_supported()
>> helper is added to skip int80 syscalls if they are not supported.
>>
>> Slawomir Rosek (2):
>>   selftests/x86/ldt_gdt: Skip int80 if not supported
>>   selftests/x86/ptrace_syscall: Skip int80 if not supported
> 
> Hi all,
> 
> Just a gentle reminder, it would be really great if someone could take
> a look. Thanks in advance.

I think grepping the configuration and cmdline files is definitely not the way
to go.

For a solution that works on existing kernels, trapping SIGSEGV and calling
int $0x80 is probably the best way to probe.

	-hpa