linux-kernel - Re: [PATCH 3/9] vt: selection, remove 2 local variables from set_selection

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Message-ID: <75287ce8-d2ce-9c00-601a-486757e8860b@suse.cz>
Date:   Mon, 24 Feb 2020 10:26:50 +0100
From:   Jiri Slaby <jslaby@...e.cz>
To:     Greg KH <gregkh@...uxfoundation.org>
Cc:     linux-serial@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 3/9] vt: selection, remove 2 local variables from
 set_selection_kernel

On 21. 02. 20, 10:32, Greg KH wrote:
> On Wed, Feb 19, 2020 at 08:39:45AM +0100, Jiri Slaby wrote:
>> multiplier and mode are not actually needed:
>> * multiplier is used only in kmalloc_array, so use "use_unicode ? 4 : 1"
>>   directly
>> * mode is used only to assign a bool in this manner:
>>   if (cond)
>>     x = true;
>>   else
>>     x = false;
>>   So do "x = cond" directly.
>>
>> Signed-off-by: Jiri Slaby <jslaby@...e.cz>
>> ---
>>  drivers/tty/vt/selection.c | 14 +++++---------
>>  1 file changed, 5 insertions(+), 9 deletions(-)
>>
>> diff --git a/drivers/tty/vt/selection.c b/drivers/tty/vt/selection.c
>> index 714992693974..6541c09d8bba 100644
>> --- a/drivers/tty/vt/selection.c
>> +++ b/drivers/tty/vt/selection.c
>> @@ -191,9 +191,9 @@ int set_selection_kernel(struct tiocl_selection *v, struct tty_struct *tty)
>>  	struct vc_data *vc = vc_cons[fg_console].d;
>>  	int new_sel_start, new_sel_end, spc;
>>  	char *bp, *obp;
>> -	int i, ps, pe, multiplier;
>> +	int i, ps, pe;
>>  	u32 c;
>> -	int mode, ret = 0;
>> +	int ret = 0;
>>  
>>  	poke_blanked_console();
>>  
>> @@ -224,11 +224,7 @@ int set_selection_kernel(struct tiocl_selection *v, struct tty_struct *tty)
>>  		clear_selection();
>>  		sel_cons = vc_cons[fg_console].d;
>>  	}
>> -	mode = vt_do_kdgkbmode(fg_console);
>> -	if (mode == K_UNICODE)
>> -		use_unicode = 1;
>> -	else
>> -		use_unicode = 0;
>> +	use_unicode = vt_do_kdgkbmode(fg_console) == K_UNICODE;
>>  
>>  	switch (v->sel_mode)
>>  	{
>> @@ -312,8 +308,8 @@ int set_selection_kernel(struct tiocl_selection *v, struct tty_struct *tty)
>>  	sel_end = new_sel_end;
>>  
>>  	/* Allocate a new buffer before freeing the old one ... */
>> -	multiplier = use_unicode ? 4 : 1;  /* chars can take up to 4 bytes */
>> -	bp = kmalloc_array((sel_end - sel_start) / 2 + 1, multiplier,
>> +	/* chars can take up to 4 bytes with unicode */
>> +	bp = kmalloc_array((sel_end - sel_start) / 2 + 1, use_unicode ? 4 : 1,
>>  			   GFP_KERNEL);
>>  	if (!bp) {
>>  		printk(KERN_WARNING "selection: kmalloc() failed\n");
>> -- 
>> 2.25.0
>>
> 
> This patch fails to apply to my tree, so I stopped here.  Can you rebase
> and resend the rest of these?

Could you be a little bit more specific? After the rebase, it still
applies cleanly for me. Perhaps the tree you are applying this to was
missing this 5.6-rc3 commit:
commit 07e6124a1a46b4b5a9b3cacc0c306b50da87abf5
Author: Jiri Slaby <jslaby@...e.cz>
Date:   Mon Feb 10 09:11:31 2020 +0100

    vt: selection, close sel_buffer race
?


thanks,
-- 
js
suse labs