linux-kernel - Re: [PATCH V4 5/9] x86/alternative: Split text_poke

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Message-ID: <e4bf9378-411f-82d2-db5f-7159b16971ee@redhat.com>
Date:   Fri, 15 Feb 2019 13:47:16 +0100
From:   Daniel Bristot de Oliveira <bristot@...hat.com>
To:     Steven Rostedt <rostedt@...dmis.org>,
        Borislav Petkov <bp@...en8.de>
Cc:     linux-kernel@...r.kernel.org, Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...hat.com>,
        "H. Peter Anvin" <hpa@...or.com>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Masami Hiramatsu <mhiramat@...nel.org>,
        Jiri Kosina <jkosina@...e.cz>,
        Josh Poimboeuf <jpoimboe@...hat.com>,
        "Peter Zijlstra (Intel)" <peterz@...radead.org>,
        Chris von Recklinghausen <crecklin@...hat.com>,
        Jason Baron <jbaron@...mai.com>, Scott Wood <swood@...hat.com>,
        Marcelo Tosatti <mtosatti@...hat.com>,
        Clark Williams <williams@...hat.com>, x86@...nel.org
Subject: Re: [PATCH V4 5/9] x86/alternative: Split text_poke_bp() into tree
 steps

On 2/8/19 1:15 AM, Steven Rostedt wrote:
> On Mon,  4 Feb 2019 20:58:58 +0100
> Daniel Bristot de Oliveira <bristot@...hat.com> wrote:
> 
>>  
>> +static void text_poke_bp_set_handler(void *addr, void *handler,
>> +				     unsigned char int3)
>> +{
>> +	bp_int3_handler = handler;
>> +	bp_int3_addr = (u8 *)addr + sizeof(int3);
>> +	text_poke(addr, &int3, sizeof(int3));
>> +}
>> +
>> +
>> +static void patch_first_byte(void *addr, const void *opcode, unsigned char int3)
>> +{
>> +	/* patch the first byte */
>> +	text_poke(addr, opcode, sizeof(int3));
>> +}
> Hmm, perhaps get rid of the first function entirely, and just do...
> (although why have the "int3" here anyway?)
> 

These helpers were created because they were used twice in the first versions of
this patch set. But with the change suggested by Masami, they are called only in
the text_poke_bp_batch() now, so I am thinking to get rid of them all (removing
this patch).

Thoughts?

Thanks!
-- Daniel