Author: Julia Lawall <julia@diku.dk> The kernel.h macro DIV_ROUND_UP performs the computation (((n) + (d) – 1) / (d)) but is perhaps more readable. An extract of the semantic patch that makes this change is as follows: (http://www.emn.fr/x-info/coccinelle/) // @haskernel@ @@ #include @depends on haskernel@ expression n,d; @@ ( – (n + d – 1) / …
Category: Linux
Oct 15 2008
FRV: Eliminate NULL test and memset after alloc_bootmem
Author: Julia Lawall <julia@diku.dk> As noted by Akinobu Mita in patch b1fceac2b9e04d278316b2faddf276015fc06e3b, alloc_bootmem and related functions never return NULL and always return a zeroed region of memory. Thus a NULL test or memset after calls to these functions is unnecessary. arch/frv/mm/init.c | 2 — 1 file changed, 2 deletions(-) This was fixed using the following …
Oct 14 2008
[SCSI] sun3x_esp: Convert && to ||
Author: Julia Lawall <julia@diku.dk> The pattern !E && !E->fld is nonsensical. The patch below updates this according to the assumption that && should be ||. But perhaps another solution was intended. The semantic patch that makes this change is as follows: (http://www.emn.fr/x-info/coccinelle/) // @disable and_comm@ expression E; identifier fld; @@ – !E && !E->fld + …
Oct 13 2008
arch/m68k/mm/kmap.c: introduce missing kfree
Author: Julia Lawall <julia@diku.dk> Error handling code following a kmalloc should free the allocated data. The semantic match that finds the problem is as follows: (http://www.emn.fr/x-info/coccinelle/) // @r exists@ local idexpression x; statement S; expression E; identifier f,l; position p1,p2; expression *ptr != NULL; @@ ( if ((x@p1 = \(kmalloc\|kzalloc\|kcalloc\)(…)) == NULL) S | x@p1 …
Oct 13 2008
drivers/char/hvc_console.c: adjust call to put_tty_driver
Author: Julia Lawall <julia@diku.dk> The call to put_tty_driver is out of place and is applied to the wrong argument. The function enclosing the patched code calls alloc_tty_driver and stores the result in drv. Subsequently, there are two occurrences of error handling code, one making a goto to put_tty and one making a goto to stop_thread. …
Oct 13 2008
drivers/serial/crisv10.c: add missing put_tty_driver
Author: Julia Lawall <julia@diku.dk> alloc_tty_driver is called at the beginning of the function containing the lines of code shown in the patch. Thus, put_tty_driver is needed before returning in the error handling code. The semantic match that finds this problem is as follows: (http://www.emn.fr/x-info/coccinelle/) // @nr exists@ local idexpression x; expression E,f; position p1,p2,p3; identifier …
Oct 10 2008
[S390] cio: Correct use of ! and &
Author: Julia Lawall <julia@diku.dk> In commit e6bafba5b4765a5a252f1b8d31cbf6d2459da337, a bug was fixed that involved converting !x & y to !(x & y). The code below shows the same pattern, and thus should perhaps be fixed in the same way. In particular, the result of !scsw_stctl(&request->irb.scsw) & SCSW_STCTL_STATUS_PEND is always just !scsw_stctl(&request->irb.scsw). The semantic patch that makes …
Oct 10 2008
RDMA/ucma: Test ucma_alloc_multicast() return against NULL, not with IS_ERR()
Author: Julien Brunel <brunel@diku.dk> In case of error, the function ucma_alloc_multicast() returns a NULL pointer, but never returns an ERR pointer. So after a call to this function, an IS_ERR test should be replaced by a NULL test. The semantic match that finds this problem is as follows: (http://www.emn.fr/x-info/coccinelle/) // @match bad_is_err_test@ expression x, E; …
Sep 26 2008
UBI: fix IS_ERR test
Author: Julien Brunel <brunel@diku.dk> In case of error, the function add_volume returns an ERR pointer. The result of IS_ERR, which is supposed to be used in a test as it is, is here checked to be less than zero, which seems odd. We suggest to replace this test by a simple IS_ERR test. A simplified …
Sep 26 2008
ALSA: sound/soc/at32: Useless NULL test
Author: Julien Brunel <brunel@diku.dk> The test (ssc != NULL) can only be reached if the call to the function ssc_request, the result of which ssc is assigned, succeeds. Moreover, two statements assign NULL to ssc just before a return, which is useless since it is a local variable. So, we suggest to delete the test …