From: Julia Lawall <julia@diku.dk>
To: isdn@linux-pingi.de, isdn4linux@listserv.isdn4linux.de,
linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org
Subject: [PATCH 3/5] drivers/isdn: Drop unnecessary NULL test
Date: Sun, 12 Jul 2009 22:05:03 +0200 (CEST) [thread overview]
Message-ID: <Pine.LNX.4.64.0907122204140.22658@ask.diku.dk> (raw)
From: Julia Lawall <julia@diku.dk>
The result of container_of should not be NULL. In particular, in this case
the argument to the enclosing function has passed though INIT_WORK, which
dereferences it, implying that its container cannot be NULL.
A simplified version of the semantic patch that makes this change is as
follows:
(http://www.emn.fr/x-info/coccinelle/)
// <smpl>
@@
identifier fn,work,x,fld;
type T;
expression E1,E2;
statement S;
@@
static fn(struct work_struct *work) {
... when != work = E1
x = container_of(work,T,fld)
... when != x = E2
- if (x == NULL) S
...
}
// </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
---
drivers/isdn/hisax/amd7930_fn.c | 2 --
drivers/isdn/hisax/hfc_pci.c | 2 --
drivers/isdn/hisax/hfc_sx.c | 2 --
drivers/isdn/hisax/icc.c | 2 --
drivers/isdn/hisax/isac.c | 2 --
drivers/isdn/hisax/w6692.c | 2 --
6 files changed, 12 deletions(-)
diff --git a/drivers/isdn/hisax/amd7930_fn.c b/drivers/isdn/hisax/amd7930_fn.c
index 341faf5..bf526a7 100644
--- a/drivers/isdn/hisax/amd7930_fn.c
+++ b/drivers/isdn/hisax/amd7930_fn.c
@@ -238,8 +238,6 @@ Amd7930_bh(struct work_struct *work)
container_of(work, struct IsdnCardState, tqueue);
struct PStack *stptr;
- if (!cs)
- return;
if (test_and_clear_bit(D_CLEARBUSY, &cs->event)) {
if (cs->debug)
debugl1(cs, "Amd7930: bh, D-Channel Busy cleared");
diff --git a/drivers/isdn/hisax/hfc_pci.c b/drivers/isdn/hisax/hfc_pci.c
index 3d337d9..d110a77 100644
--- a/drivers/isdn/hisax/hfc_pci.c
+++ b/drivers/isdn/hisax/hfc_pci.c
@@ -1506,8 +1506,6 @@ hfcpci_bh(struct work_struct *work)
u_long flags;
// struct PStack *stptr;
- if (!cs)
- return;
if (test_and_clear_bit(D_L1STATECHANGE, &cs->event)) {
if (!cs->hw.hfcpci.nt_mode)
switch (cs->dc.hfcpci.ph_state) {
diff --git a/drivers/isdn/hisax/hfc_sx.c b/drivers/isdn/hisax/hfc_sx.c
index d92e8d6..419f87c 100644
--- a/drivers/isdn/hisax/hfc_sx.c
+++ b/drivers/isdn/hisax/hfc_sx.c
@@ -1255,8 +1255,6 @@ hfcsx_bh(struct work_struct *work)
container_of(work, struct IsdnCardState, tqueue);
u_long flags;
- if (!cs)
- return;
if (test_and_clear_bit(D_L1STATECHANGE, &cs->event)) {
if (!cs->hw.hfcsx.nt_mode)
switch (cs->dc.hfcsx.ph_state) {
diff --git a/drivers/isdn/hisax/icc.c b/drivers/isdn/hisax/icc.c
index 682cac3..9aba646 100644
--- a/drivers/isdn/hisax/icc.c
+++ b/drivers/isdn/hisax/icc.c
@@ -83,8 +83,6 @@ icc_bh(struct work_struct *work)
container_of(work, struct IsdnCardState, tqueue);
struct PStack *stptr;
- if (!cs)
- return;
if (test_and_clear_bit(D_CLEARBUSY, &cs->event)) {
if (cs->debug)
debugl1(cs, "D-Channel Busy cleared");
diff --git a/drivers/isdn/hisax/isac.c b/drivers/isdn/hisax/isac.c
index 07b1673..a19354d 100644
--- a/drivers/isdn/hisax/isac.c
+++ b/drivers/isdn/hisax/isac.c
@@ -86,8 +86,6 @@ isac_bh(struct work_struct *work)
container_of(work, struct IsdnCardState, tqueue);
struct PStack *stptr;
- if (!cs)
- return;
if (test_and_clear_bit(D_CLEARBUSY, &cs->event)) {
if (cs->debug)
debugl1(cs, "D-Channel Busy cleared");
diff --git a/drivers/isdn/hisax/w6692.c b/drivers/isdn/hisax/w6692.c
index bb1c8dd..c4d862c 100644
--- a/drivers/isdn/hisax/w6692.c
+++ b/drivers/isdn/hisax/w6692.c
@@ -105,8 +105,6 @@ W6692_bh(struct work_struct *work)
container_of(work, struct IsdnCardState, tqueue);
struct PStack *stptr;
- if (!cs)
- return;
if (test_and_clear_bit(D_CLEARBUSY, &cs->event)) {
if (cs->debug)
debugl1(cs, "D-Channel Busy cleared");
next reply other threads:[~2009-07-12 20:14 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-07-12 20:05 Julia Lawall [this message]
2009-07-24 10:55 ` Karsten Keil
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