[PATCH] BUILD_BUG_ON sucks

From: Alexey Dobriyan
Date: Sat Aug 16 2008 - 06:10:32 EST

BUILD_BUG_ON should have never existed -- BUG_ON could upgrade itself to
compile-breaking version if compiler has enough information and this is
what patch does.

The only downside is that one can't write BUG_ON(1) anymore.

Note: this compile-breaks jbd, jbd2, tipc,
what this code is supposed to do?

journal = handle->h_transaction->t_journal;
if (!journal_set_features(journal, 0, 0, JFS_FEATURE_INCOMPAT_REVOKE)) {
J_ASSERT (!"Cannot set revoke feature!");
^^^^
return -EINVAL;
}

Signed-off-by: Alexey Dobriyan <adobriyan@xxxxxxxxx>
---

arch/cris/arch-v10/kernel/io_interface_mux.c | 8 ++++----
arch/powerpc/include/asm/bug.h | 3 +--
drivers/infiniband/core/cma.c | 2 +-
drivers/infiniband/core/mad.c | 2 +-
drivers/infiniband/hw/amso1100/c2_ae.c | 2 +-
drivers/infiniband/hw/cxgb3/cxio_hal.c | 2 +-
drivers/infiniband/hw/cxgb3/iwch_cm.c | 6 +++---
drivers/mmc/host/wbsd.c | 2 +-
drivers/net/wireless/b43legacy/b43legacy.h | 2 ++
drivers/net/wireless/b43legacy/main.c | 12 ++++++------
drivers/net/wireless/b43legacy/phy.c | 2 +-
drivers/net/wireless/b43legacy/radio.c | 22 +++++++++++-----------
drivers/net/wireless/b43legacy/xmit.c | 12 ++++++------
drivers/scsi/device_handler/scsi_dh_emc.c | 2 +-
drivers/ssb/scan.c | 4 ++--
drivers/ssb/ssb_private.h | 2 ++
fs/jbd2/journal.c | 2 +-
include/asm-generic/bug.h | 8 +++++++-
include/asm-mips/bug.h | 5 ++++-
kernel/sched.c | 2 +-
net/bluetooth/rfcomm/tty.c | 2 +-
21 files changed, 58 insertions(+), 46 deletions(-)

--- a/arch/cris/arch-v10/kernel/io_interface_mux.c
+++ b/arch/cris/arch-v10/kernel/io_interface_mux.c
@@ -650,7 +650,7 @@ int cris_request_io_interface(enum cris_io_interface ioif, const char *device_id
if_group_use = interfaces[ioif].group_f;
break;
default:
- BUG_ON(1);
+ BUG();
}

if (if_group_use & grp->used) {
@@ -799,7 +799,7 @@ int cris_request_io_interface(enum cris_io_interface ioif, const char *device_id
if_group_use = interfaces[ioif].group_f;
break;
default:
- BUG_ON(1);
+ BUG();
}
grp->used |= if_group_use;

@@ -891,11 +891,11 @@ void cris_free_io_interface(enum cris_io_interface ioif)
if_group_use = interfaces[ioif].group_f;
break;
default:
- BUG_ON(1);
+ BUG();
}

if ((grp->used & if_group_use) != if_group_use)
- BUG_ON(1);
+ BUG();
grp->used = grp->used & ~if_group_use;

group_set = clear_group_from_set(group_set, grp);
--- a/arch/powerpc/include/asm/bug.h
+++ b/arch/powerpc/include/asm/bug.h
@@ -71,8 +71,7 @@

#define BUG_ON(x) do { \
if (__builtin_constant_p(x)) { \
- if (x) \
- BUG(); \
+ (void)sizeof(char[1 - 2 * !!(x)]); \
} else { \
__asm__ __volatile__( \
"1: "PPC_TLNEI" %4,0\n" \
--- a/drivers/infiniband/core/cma.c
+++ b/drivers/infiniband/core/cma.c
@@ -1252,7 +1252,7 @@ static int cma_iw_handler(struct iw_cm_id *iw_id, struct iw_cm_event *iw_event)
event.event = RDMA_CM_EVENT_ESTABLISHED;
break;
default:
- BUG_ON(1);
+ BUG();
}

event.status = iw_event->status;
--- a/drivers/infiniband/core/mad.c
+++ b/drivers/infiniband/core/mad.c
@@ -2249,7 +2249,7 @@ static void ib_mad_completion_handler(struct work_struct *work)
ib_mad_recv_done_handler(port_priv, &wc);
break;
default:
- BUG_ON(1);
+ BUG();
break;
}
} else
--- a/drivers/infiniband/hw/amso1100/c2_ae.c
+++ b/drivers/infiniband/hw/amso1100/c2_ae.c
@@ -256,7 +256,7 @@ void c2_ae_event(struct c2_dev *c2dev, u32 mq_index)
cm_id->event_handler(cm_id, &cm_event);
break;
default:
- BUG_ON(1);
+ BUG();
pr_debug("%s:%d Unexpected event_id=%d on QP=%p, "
"CM_ID=%p\n",
__func__, __LINE__,
--- a/drivers/infiniband/hw/cxgb3/cxio_hal.c
+++ b/drivers/infiniband/hw/cxgb3/cxio_hal.c
@@ -109,7 +109,7 @@ int cxio_hal_cq_op(struct cxio_rdev *rdev_p, struct t3_cq *cq,
while (!CQ_VLD_ENTRY(rptr, cq->size_log2, cqe)) {
udelay(1);
if (i++ > 1000000) {
- BUG_ON(1);
+ BUG();
printk(KERN_ERR "%s: stalled rnic\n",
rdev_p->dev_name);
return -EIO;
--- a/drivers/infiniband/hw/cxgb3/iwch_cm.c
+++ b/drivers/infiniband/hw/cxgb3/iwch_cm.c
@@ -1493,7 +1493,7 @@ static int peer_close(struct t3cdev *tdev, struct sk_buff *skb, void *ctx)
disconnect = 0;
break;
default:
- BUG_ON(1);
+ BUG();
}
spin_unlock_irqrestore(&ep->com.lock, flags);
if (disconnect)
@@ -1590,7 +1590,7 @@ static int peer_abort(struct t3cdev *tdev, struct sk_buff *skb, void *ctx)
spin_unlock_irqrestore(&ep->com.lock, flags);
return CPL_RET_BUF_DONE;
default:
- BUG_ON(1);
+ BUG();
break;
}
dst_confirm(ep->dst);
@@ -1653,7 +1653,7 @@ static int close_con_rpl(struct t3cdev *tdev, struct sk_buff *skb, void *ctx)
case DEAD:
break;
default:
- BUG_ON(1);
+ BUG();
break;
}
spin_unlock_irqrestore(&ep->com.lock, flags);
--- a/drivers/mmc/host/wbsd.c
+++ b/drivers/mmc/host/wbsd.c
@@ -1416,7 +1416,7 @@ kfree:
/*
* If we've gotten here then there is some kind of alignment bug
*/
- BUG_ON(1);
+ BUG();

dma_unmap_single(mmc_dev(host->mmc), host->dma_addr,
WBSD_DMA_SIZE, DMA_BIDIRECTIONAL);
--- a/drivers/net/wireless/b43legacy/b43legacy.h
+++ b/drivers/net/wireless/b43legacy/b43legacy.h
@@ -342,12 +342,14 @@ enum {
BUG_ON(expr); \
} \
} while (0)
+# define B43legacy_BUG() BUG()
# define B43legacy_DEBUG 1
#else
/* This will evaluate the argument even if debugging is disabled. */
static inline bool __b43legacy_warn_on_dummy(bool x) { return x; }
# define B43legacy_WARN_ON(x) __b43legacy_warn_on_dummy(unlikely(!!(x)))
# define B43legacy_BUG_ON(x) do { /* nothing */ } while (0)
+# define B43legacy_BUG() do {} while (0)
# define B43legacy_DEBUG 0
#endif

--- a/drivers/net/wireless/b43legacy/main.c
+++ b/drivers/net/wireless/b43legacy/main.c
@@ -649,7 +649,7 @@ void b43legacy_dummy_transmission(struct b43legacy_wldev *dev)
buffer[0] = 0x000B846E;
break;
default:
- B43legacy_BUG_ON(1);
+ B43legacy_BUG();
return;
}

@@ -2010,7 +2010,7 @@ static void b43legacy_rate_memory_init(struct b43legacy_wldev *dev)
b43legacy_rate_memory_write(dev, B43legacy_CCK_RATE_11MB, 0);
break;
default:
- B43legacy_BUG_ON(1);
+ B43legacy_BUG();
}
}

@@ -2032,7 +2032,7 @@ static void b43legacy_mgmtframe_txantenna(struct b43legacy_wldev *dev,
ant |= B43legacy_TX4_PHY_ANTLAST;
break;
default:
- B43legacy_BUG_ON(1);
+ B43legacy_BUG();
}

/* FIXME We also need to set the other flags of the PHY control
@@ -2442,7 +2442,7 @@ static const char *phymode_to_string(unsigned int phymode)
case B43legacy_PHYMODE_G:
return "G";
default:
- B43legacy_BUG_ON(1);
+ B43legacy_BUG();
}
return "";
}
@@ -2887,7 +2887,7 @@ static int b43legacy_phy_versioning(struct b43legacy_wldev *dev)
unsupported = 1;
break;
default:
- B43legacy_BUG_ON(1);
+ B43legacy_BUG();
}
if (unsupported) {
b43legacyerr(dev->wl, "FOUND UNSUPPORTED RADIO "
@@ -3563,7 +3563,7 @@ static int b43legacy_wireless_core_attach(struct b43legacy_wldev *dev)
have_gphy = 1;
break;
default:
- B43legacy_BUG_ON(1);
+ B43legacy_BUG();
}
}
dev->phy.gmode = (have_gphy || have_bphy);
--- a/drivers/net/wireless/b43legacy/phy.c
+++ b/drivers/net/wireless/b43legacy/phy.c
@@ -1760,7 +1760,7 @@ static s8 b43legacy_phy_estimate_power_out(struct b43legacy_wldev *dev, s8 tssi)
dbm = phy->tssi2dbm[tmp];
break;
default:
- B43legacy_BUG_ON(1);
+ B43legacy_BUG();
}

return dbm;
--- a/drivers/net/wireless/b43legacy/radio.c
+++ b/drivers/net/wireless/b43legacy/radio.c
@@ -131,7 +131,7 @@ u16 b43legacy_radio_read16(struct b43legacy_wldev *dev, u16 offset)
offset |= 0x80;
break;
default:
- B43legacy_BUG_ON(1);
+ B43legacy_BUG();
}

b43legacy_write16(dev, B43legacy_MMIO_RADIO_CONTROL, offset);
@@ -811,7 +811,7 @@ void b43legacy_calc_nrssi_slope(struct b43legacy_wldev *dev)
b43legacy_calc_nrssi_threshold(dev);
break;
default:
- B43legacy_BUG_ON(1);
+ B43legacy_BUG();
}
}

@@ -910,7 +910,7 @@ void b43legacy_calc_nrssi_threshold(struct b43legacy_wldev *dev)
}
break;
default:
- B43legacy_BUG_ON(1);
+ B43legacy_BUG();
}
}

@@ -946,7 +946,7 @@ static u16 _stack_restore(u32 *stackptr,
continue;
return ((*stackptr & 0xFFFF0000) >> 16);
}
- B43legacy_BUG_ON(1);
+ B43legacy_BUG();

return 0;
}
@@ -1227,7 +1227,7 @@ b43legacy_radio_interference_mitigation_enable(struct b43legacy_wldev *dev,
b43legacy_calc_nrssi_slope(dev);
break;
default:
- B43legacy_BUG_ON(1);
+ B43legacy_BUG();
}
}

@@ -1325,7 +1325,7 @@ b43legacy_radio_interference_mitigation_disable(struct b43legacy_wldev *dev,
b43legacy_calc_nrssi_slope(dev);
break;
default:
- B43legacy_BUG_ON(1);
+ B43legacy_BUG();
}
}

@@ -1419,7 +1419,7 @@ static u16 b43legacy_get_812_value(struct b43legacy_wldev *dev, u8 lpd)
case LPD(1, 0, 0):
return 0x30B3;
default:
- B43legacy_BUG_ON(1);
+ B43legacy_BUG();
}
} else {
switch (lpd) {
@@ -1432,7 +1432,7 @@ static u16 b43legacy_get_812_value(struct b43legacy_wldev *dev, u8 lpd)
case LPD(1, 0, 0):
return 0x20B3;
default:
- B43legacy_BUG_ON(1);
+ B43legacy_BUG();
}
}
} else {
@@ -1474,7 +1474,7 @@ static u16 b43legacy_get_812_value(struct b43legacy_wldev *dev, u8 lpd)
case LPD(1, 0, 0):
return (0x2093 | loop_or);
default:
- B43legacy_BUG_ON(1);
+ B43legacy_BUG();
}
} else {
switch (lpd) {
@@ -1486,7 +1486,7 @@ static u16 b43legacy_get_812_value(struct b43legacy_wldev *dev, u8 lpd)
case LPD(1, 0, 0):
return (0x0093 | loop_or);
default:
- B43legacy_BUG_ON(1);
+ B43legacy_BUG();
}
}
}
@@ -2111,7 +2111,7 @@ void b43legacy_radio_turn_on(struct b43legacy_wldev *dev)
B43legacy_WARN_ON(err);
break;
default:
- B43legacy_BUG_ON(1);
+ B43legacy_BUG();
}
phy->radio_on = 1;
}
--- a/drivers/net/wireless/b43legacy/xmit.c
+++ b/drivers/net/wireless/b43legacy/xmit.c
@@ -49,7 +49,7 @@ static u8 b43legacy_plcp_get_bitrate_idx_cck(struct b43legacy_plcp_hdr6 *plcp)
case 0x6E:
return 3;
}
- B43legacy_BUG_ON(1);
+ B43legacy_BUG();
return -1;
}

@@ -77,7 +77,7 @@ static u8 b43legacy_plcp_get_bitrate_idx_ofdm(struct b43legacy_plcp_hdr6 *plcp,
case 0xC:
return base + 7;
}
- B43legacy_BUG_ON(1);
+ B43legacy_BUG();
return -1;
}

@@ -93,7 +93,7 @@ u8 b43legacy_plcp_get_ratecode_cck(const u8 bitrate)
case B43legacy_CCK_RATE_11MB:
return 0x6E;
}
- B43legacy_BUG_ON(1);
+ B43legacy_BUG();
return 0;
}

@@ -117,7 +117,7 @@ u8 b43legacy_plcp_get_ratecode_ofdm(const u8 bitrate)
case B43legacy_OFDM_RATE_54MB:
return 0xC;
}
- B43legacy_BUG_ON(1);
+ B43legacy_BUG();
return 0;
}

@@ -180,7 +180,7 @@ static u8 b43legacy_calc_fallback_rate(u8 bitrate)
case B43legacy_OFDM_RATE_54MB:
return B43legacy_OFDM_RATE_48MB;
}
- B43legacy_BUG_ON(1);
+ B43legacy_BUG();
return 0;
}

@@ -289,7 +289,7 @@ static int generate_txhdr_fw3(struct b43legacy_wldev *dev,
phy_ctl |= B43legacy_TX4_PHY_ANT1;
break;
default:
- B43legacy_BUG_ON(1);
+ B43legacy_BUG();
}

/* MAC control */
--- a/drivers/scsi/device_handler/scsi_dh_emc.c
+++ b/drivers/scsi/device_handler/scsi_dh_emc.c
@@ -298,7 +298,7 @@ static struct request *get_req(struct scsi_device *sdev, int cmd,
memset(buffer, 0, len);
break;
default:
- BUG_ON(1);
+ BUG();
break;
}

--- a/drivers/ssb/scan.c
+++ b/drivers/ssb/scan.c
@@ -203,7 +203,7 @@ void ssb_iounmap(struct ssb_bus *bus)
#ifdef CONFIG_SSB_PCIHOST
pci_iounmap(bus->host_pci, bus->mmio);
#else
- SSB_BUG_ON(1); /* Can't reach this code. */
+ SSB_BUG(); /* Can't reach this code. */
#endif
break;
}
@@ -227,7 +227,7 @@ static void __iomem *ssb_ioremap(struct ssb_bus *bus,
#ifdef CONFIG_SSB_PCIHOST
mmio = pci_iomap(bus->host_pci, 0, ~0UL);
#else
- SSB_BUG_ON(1); /* Can't reach this code. */
+ SSB_BUG(); /* Can't reach this code. */
#endif
break;
}
--- a/drivers/ssb/ssb_private.h
+++ b/drivers/ssb/ssb_private.h
@@ -23,10 +23,12 @@
#ifdef CONFIG_SSB_DEBUG
# define SSB_WARN_ON(x) WARN_ON(x)
# define SSB_BUG_ON(x) BUG_ON(x)
+# define SSB_BUG() BUG()
#else
static inline int __ssb_do_nothing(int x) { return x; }
# define SSB_WARN_ON(x) __ssb_do_nothing(unlikely(!!(x)))
# define SSB_BUG_ON(x) __ssb_do_nothing(unlikely(!!(x)))
+# define SSB_BUG() do {} while (0)
#endif


--- a/fs/jbd2/journal.c
+++ b/fs/jbd2/journal.c
@@ -731,7 +731,7 @@ static int jbd2_seq_history_show(struct seq_file *seq, void *v)
ts->u.chp.cs_written, ts->u.chp.cs_dropped,
ts->u.chp.cs_forced_to_close);
else
- J_ASSERT(0);
+ BUG();
return 0;
}

--- a/include/asm-generic/bug.h
+++ b/include/asm-generic/bug.h
@@ -28,7 +28,13 @@ struct bug_entry {
#endif

#ifndef HAVE_ARCH_BUG_ON
-#define BUG_ON(condition) do { if (unlikely(condition)) BUG(); } while(0)
+#define BUG_ON(condition) \
+ do { \
+ if (__builtin_constant_p(condition)) \
+ (void)sizeof(char[1 - 2 * !!(condition)]); \
+ else if (unlikely(condition)) \
+ BUG(); \
+ } while (0)
#endif

#ifndef __WARN
--- a/include/asm-mips/bug.h
+++ b/include/asm-mips/bug.h
@@ -18,7 +18,10 @@ do { \

#define BUG_ON(condition) \
do { \
- __asm__ __volatile__("tne $0, %0, %1" \
+ if (__builtin_constant_p(condition)) \
+ (void)sizeof(char[1 - 2 * !!(condition)]); \
+ else
+ __asm__ __volatile__("tne $0, %0, %1" \
: : "r" (condition), "i" (BRK_BUG)); \
} while (0)

--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -2798,7 +2798,7 @@ static int double_lock_balance(struct rq *this_rq, struct rq *busiest)
if (unlikely(!irqs_disabled())) {
/* printk() doesn't work good under rq->lock */
spin_unlock(&this_rq->lock);
- BUG_ON(1);
+ BUG();
}
if (unlikely(!spin_trylock(&busiest->lock))) {
if (busiest < this_rq) {
--- a/net/bluetooth/rfcomm/tty.c
+++ b/net/bluetooth/rfcomm/tty.c
@@ -331,7 +331,7 @@ static void rfcomm_dev_del(struct rfcomm_dev *dev)
BT_DBG("dev %p", dev);

if (test_bit(RFCOMM_TTY_RELEASED, &dev->flags))
- BUG_ON(1);
+ BUG();
else
set_bit(RFCOMM_TTY_RELEASED, &dev->flags);


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