[LTP] [PATCH] mmap14: Convert to new API

Ricardo B. Marliere rbm@suse.com
Wed Oct 30 20:37:13 CET 2024


Hi Petr!

On 30 Oct 24 17:21, Petr Vorel wrote:
> Hi Ricardo,
> 
> very nice, few minor things below.
> 
> > Signed-off-by: Ricardo B. Marliere <rbm@suse.com>
> > ---
> >  testcases/kernel/syscalls/mmap/mmap14.c | 97 ++++++++++-----------------------
> >  1 file changed, 30 insertions(+), 67 deletions(-)
> 
> > diff --git a/testcases/kernel/syscalls/mmap/mmap14.c b/testcases/kernel/syscalls/mmap/mmap14.c
> > index 31632601bbed85b60f1dfee7044bf961b1f2a756..63a2f9e4cab2f7ab12b1ad982bc690f9fabcc252 100644
> > --- a/testcases/kernel/syscalls/mmap/mmap14.c
> > +++ b/testcases/kernel/syscalls/mmap/mmap14.c
> > @@ -1,22 +1,12 @@
> > +// SPDX-License-Identifier: GPL-2.0-or-later
> >  /*
> >   * Copyright (c) 2013 FNST, DAN LI <li.dan@cn.fujitsu.com>
> >   *
> nit: blank space above (ideally to remove). You could also add your/SUSE/LTP copyright.
> 
> > - * This program is free software;  you can redistribute it and/or modify
> > - * it under the terms of the GNU General Public License as published by
> > - * the Free Software Foundation; either version 2 of the License, or
> > - * (at your option) any later version.
> > - *
> > - * This program is distributed in the hope that it will be useful,
> > - * but WITHOUT ANY WARRANTY;  without even the implied warranty of
> > - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
> > - * the GNU General Public License for more details.
> > - *
> > - * You should have received a copy of the GNU General Public License
> > - * along with this program;  if not, write to the Free Software
> > - * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
> >   */
> 
> > -/*
> > +/*\
> > + * [Description]
> > + *
> >   * Test Description:
> >   *  Verify MAP_LOCKED works fine.
> >   *  "Lock the pages of the mapped region into memory in the manner of mlock(2)."
> 
> I would use something like:
> 
> /*\
>  * [Description]
>  *
>  * Verify basic functionality of mmap(2) with MAP_LOCKED.
>  *
>  * mmap(2) should succeed returning the address of the mapped region,
>  * and this region should be locked into memory.
>  */
> 
> Also, having more than one space after '*' causes different formatting in
> auto-generated doc (it will become <pre>...</pre>)
> You can see it if you have asciidoctor (or asciidoc) installed and run
> 
> cd metadata && make
> resulting docs is in ../docparse/*.html
> 
> We publish the docs in releases, e.g.:
> https://github.com/linux-test-project/ltp/releases/download/20240930/metadata.20240930.html

Nice!

> 
> > @@ -28,65 +18,45 @@
> >  #include <stdio.h>
> >  #include <sys/mman.h>
> 
> > -#include "test.h"
> > +#include "tst_test.h"
> 
> >  #define TEMPFILE        "mmapfile"
> >  #define MMAPSIZE        (1UL<<20)
> >  #define LINELEN         256
> 
> > -char *TCID = "mmap14";
> > -int TST_TOTAL = 1;
> > -
> >  static char *addr;
> 
> >  static void getvmlck(unsigned int *lock_sz);
> Ideally you just move getvmlck() code above instead using function signature.
> 
> > +static void run(unsigned int n)
> 
> Here n is unused. That's why you should use void
> 
> static void run(void)
> 
> And below in the struct tst_test test just:
> 	.test_all = run,
> 
> See our old doc (not yet converted to the new format):
> https://github.com/linux-test-project/ltp/blob/master/doc/old/C-Test-API.asciidoc#11-basic-test-structure
> 
> >  {
> >  	unsigned int sz_before;
> >  	unsigned int sz_after;
> >  	unsigned int sz_ch;
> 
> > -		addr = mmap(NULL, MMAPSIZE, PROT_READ | PROT_WRITE,
> > -			    MAP_PRIVATE | MAP_LOCKED | MAP_ANONYMOUS,
> > -			    -1, 0);
> > +	addr = mmap(NULL, MMAPSIZE, PROT_READ | PROT_WRITE,
> > +			MAP_PRIVATE | MAP_LOCKED | MAP_ANONYMOUS,
> > +			-1, 0);
> very nit (just formatting - feel free to reformat the old test):
> 
> 	addr = mmap(NULL, MMAPSIZE, PROT_READ | PROT_WRITE,
> 			MAP_PRIVATE | MAP_LOCKED | MAP_ANONYMOUS, -1, 0);
> 
> > -		if (addr == MAP_FAILED) {
> > -			tst_resm(TFAIL | TERRNO, "mmap of %s failed", TEMPFILE);
> > -			continue;
> > -		}
> > +	if (addr == MAP_FAILED)
> > +		tst_res(TFAIL | TERRNO, "mmap of %s failed", TEMPFILE);
> You need to have return here (like in mmap05.c) to skip the rest of the test.
> In the old API this was achieved by continue.
> 
> > -		getvmlck(&sz_after);
> > +	getvmlck(&sz_after);
> 
> > -		sz_ch = sz_after - sz_before;
> > -		if (sz_ch == MMAPSIZE / 1024) {
> > -			tst_resm(TPASS, "Functionality of mmap() "
> > -					"successful");
> > -		} else {
> > -			tst_resm(TFAIL, "Expected %luK locked, "
> > -					"get %uK locked",
> > -					MMAPSIZE / 1024, sz_ch);
> > -		}
> > -
> > -		if (munmap(addr, MMAPSIZE) != 0)
> > -			tst_brkm(TFAIL | TERRNO, NULL, "munmap failed");
> > +	sz_ch = sz_after - sz_before;
> > +	if (sz_ch == MMAPSIZE / 1024) {
> > +		tst_res(TPASS, "Functionality of mmap() "
> > +				"successful");
> This is not much useful information. Also IMHO it's better to avoid splitting
> string (not ideal for grepping)
> 
> > +	} else {
> > +		tst_res(TFAIL, "Expected %luK locked, "
> > +				"get %uK locked",
> > +				MMAPSIZE / 1024, sz_ch);
> >  	}
> 
> Maybe something like:
> 	if (sz_ch == MMAPSIZE / 1024) {
> 		tst_res(TPASS, "mmap() locked %uK", sz_ch);
> 	} else {
> 		tst_res(TFAIL, "Expected %luK locked, get %uK locked",
> 				MMAPSIZE / 1024, sz_ch);
> 	}
> 
> > +	if (munmap(addr, MMAPSIZE) != 0)
> > +		tst_res(TFAIL | TERRNO, "munmap failed");
> The above should be replaced with:
> 
> 	SAFE_MUNMAP((char *)addr, sz_ch);
> 
> >  }
> 
> >  void getvmlck(unsigned int *lock_sz)
> Here is missing static.
> 
> > @@ -97,7 +67,7 @@ void getvmlck(unsigned int *lock_sz)
> 
> >  	fstatus = fopen("/proc/self/status", "r");
> 
> Please, use here:
> 
> 	fstatus = SAFE_FOPEN("/proc/self/status", "r");
> (it needs #include "tst_safe_stdio.h")

Ah, makes sense.

> 
> See old (not yet converted docs):
> https://github.com/linux-test-project/ltp/blob/master/doc/old/C-Test-API.asciidoc#a-word-about-the-cleanup-callback
> 
> Or in our old tutorial (already converted to the new API):
> https://linux-test-project.readthedocs.io/en/latest/developers/test_case_tutorial.html
> 
> >  	if (fstatus == NULL)
> > -		tst_brkm(TFAIL | TERRNO, NULL, "Open dev status failed");
> > +		tst_res(TFAIL | TERRNO, "Open dev status failed");
> Then the check above is not needed. Also beware, tst_brk() (or tst_brkm()) quits
> testing. But tst_res() usually not (tst_res(TBROK, ...) still quits testing, but
> that's kind of misusing the API), thus you changed a test workflow.

Ouch, indeed..

> 
> >  	while (fgets(line, LINELEN, fstatus) != NULL)
> >  		if (strstr(line, "VmLck") != NULL)
> > @@ -105,20 +75,13 @@ void getvmlck(unsigned int *lock_sz)
> 
> >  	ret = sscanf(line, "%*[^0-9]%d%*[^0-9]", lock_sz);
> >  	if (ret != 1)
> > -		tst_brkm(TFAIL | TERRNO, NULL, "Get lock size failed");
> > +		tst_res(TFAIL | TERRNO, "Get lock size failed");
> Again, SAFE_SSCANF() instead of check, also remember tst_brk() tst_res() difference.
> int ret is then not needed.
> 
> Also, we usually use in tests SAFE_FCLOSE(fstatus) instead of fclose(fstatus)
> (it checks the return value and yells if unexpected).
> 
> ...
> > +	.needs_root = 1,
> 
> As I noted above, instead of these two:
> > +	.test = run,
> > +	.tcnt = 1,
> 
> please use just:
> .test_all = run,
> 
> If you want, I can merge with the following diff below
> (+ the copyright you prefer me to add).
> Or just send another version.

Many thanks for reviewing and guidance. I'll make sure to properly read
the documentation for next time so as to avoid wasting review cycles :)

I'll send a v2.

> 
> Kind regards,
> Petr
> 
> +++ testcases/kernel/syscalls/mmap/mmap14.c
> @@ -1,23 +1,20 @@
>  // SPDX-License-Identifier: GPL-2.0-or-later
>  /*
>   * Copyright (c) 2013 FNST, DAN LI <li.dan@cn.fujitsu.com>
> - *
>   */
>  
>  /*\
>   * [Description]
>   *
> - * Test Description:
> - *  Verify MAP_LOCKED works fine.
> - *  "Lock the pages of the mapped region into memory in the manner of mlock(2)."
> + * Verify basic functionality of mmap(2) with MAP_LOCKED.
>   *
> - * Expected Result:
> - *  mmap() should succeed returning the address of the mapped region,
> - *  and this region should be locked into memory.
> + * mmap(2) should succeed returning the address of the mapped region,
> + * and this region should be locked into memory.
>   */
> +
>  #include <stdio.h>
>  #include <sys/mman.h>
> -
> +#include "tst_safe_stdio.h"
>  #include "tst_test.h"
>  
>  #define TEMPFILE        "mmapfile"
> @@ -26,9 +23,23 @@
>  
>  static char *addr;
>  
> -static void getvmlck(unsigned int *lock_sz);
> +static void getvmlck(unsigned int *lock_sz)
> +{
> +	char line[LINELEN];
> +	FILE *fstatus = NULL;
> +
> +	fstatus = SAFE_FOPEN("/proc/self/status", "r");
> +
> +	while (fgets(line, LINELEN, fstatus) != NULL)
> +		if (strstr(line, "VmLck") != NULL)
> +			break;
> +
> +	SAFE_SSCANF(line, "%*[^0-9]%d%*[^0-9]", lock_sz);
> +
> +	SAFE_FCLOSE(fstatus);
> +}
>  
> -static void run(unsigned int n)
> +static void run(void)
>  {
>  	unsigned int sz_before;
>  	unsigned int sz_after;
> @@ -37,8 +48,7 @@ static void run(unsigned int n)
>  	getvmlck(&sz_before);
>  
>  	addr = mmap(NULL, MMAPSIZE, PROT_READ | PROT_WRITE,
> -			MAP_PRIVATE | MAP_LOCKED | MAP_ANONYMOUS,
> -			-1, 0);
> +			MAP_PRIVATE | MAP_LOCKED | MAP_ANONYMOUS, -1, 0);
>  
>  	if (addr == MAP_FAILED)
>  		tst_res(TFAIL | TERRNO, "mmap of %s failed", TEMPFILE);
> @@ -47,41 +57,16 @@ static void run(unsigned int n)
>  
>  	sz_ch = sz_after - sz_before;
>  	if (sz_ch == MMAPSIZE / 1024) {
> -		tst_res(TPASS, "Functionality of mmap() "
> -				"successful");
> +		tst_res(TPASS, "mmap() locked %uK", sz_ch);
>  	} else {
> -		tst_res(TFAIL, "Expected %luK locked, "
> -				"get %uK locked",
> +		tst_res(TFAIL, "Expected %luK locked, get %uK locked",
>  				MMAPSIZE / 1024, sz_ch);
>  	}
>  
> -	if (munmap(addr, MMAPSIZE) != 0)
> -		tst_res(TFAIL | TERRNO, "munmap failed");
> -}
> -
> -void getvmlck(unsigned int *lock_sz)
> -{
> -	int ret;
> -	char line[LINELEN];
> -	FILE *fstatus = NULL;
> -
> -	fstatus = fopen("/proc/self/status", "r");
> -	if (fstatus == NULL)
> -		tst_res(TFAIL | TERRNO, "Open dev status failed");
> -
> -	while (fgets(line, LINELEN, fstatus) != NULL)
> -		if (strstr(line, "VmLck") != NULL)
> -			break;
> -
> -	ret = sscanf(line, "%*[^0-9]%d%*[^0-9]", lock_sz);
> -	if (ret != 1)
> -		tst_res(TFAIL | TERRNO, "Get lock size failed");
> -
> -	fclose(fstatus);
> +	SAFE_MUNMAP((char *)addr, sz_ch);
>  }
>  
>  static struct tst_test test = {
>  	.needs_root = 1,
> -	.test = run,
> -	.tcnt = 1,
> +	.test_all = run,
>  };


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