MIPS: Fix logic errors in bitops.c
commit 92d11594f6 (MIPS: Remove irqflags.h dependency from bitops.h)
factored some of the bitops code out into a separate file
(arch/mips/lib/bitops.c). Unfortunately the logic converting a bit
mask into a boolean result was lost in some of the functions. We had:
int res;
unsigned long shifted_result_bit;
.
.
.
res = shifted_result_bit;
return res;
Which truncates off the high 32 bits (thus yielding an incorrect
value) on 64-bit systems.
The manifestation of this is that a non-SMP 64-bit kernel will not
boot as the bitmap operations in bootmem.c are all screwed up.
Signed-off-by: David Daney <david.daney@cavium.com>
Cc: linux-mips@linux-mips.org
Cc: Jim Quinlan <jim2101024@gmail.com>
Cc: stable@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/4965/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/lib/bitops.c b/arch/mips/lib/bitops.c
index 81f1dcf..a64daee 100644
--- a/arch/mips/lib/bitops.c
+++ b/arch/mips/lib/bitops.c
@@ -90,12 +90,12 @@
unsigned bit = nr & SZLONG_MASK;
unsigned long mask;
unsigned long flags;
- unsigned long res;
+ int res;
a += nr >> SZLONG_LOG;
mask = 1UL << bit;
raw_local_irq_save(flags);
- res = (mask & *a);
+ res = (mask & *a) != 0;
*a |= mask;
raw_local_irq_restore(flags);
return res;
@@ -116,12 +116,12 @@
unsigned bit = nr & SZLONG_MASK;
unsigned long mask;
unsigned long flags;
- unsigned long res;
+ int res;
a += nr >> SZLONG_LOG;
mask = 1UL << bit;
raw_local_irq_save(flags);
- res = (mask & *a);
+ res = (mask & *a) != 0;
*a |= mask;
raw_local_irq_restore(flags);
return res;
@@ -141,12 +141,12 @@
unsigned bit = nr & SZLONG_MASK;
unsigned long mask;
unsigned long flags;
- unsigned long res;
+ int res;
a += nr >> SZLONG_LOG;
mask = 1UL << bit;
raw_local_irq_save(flags);
- res = (mask & *a);
+ res = (mask & *a) != 0;
*a &= ~mask;
raw_local_irq_restore(flags);
return res;
@@ -166,12 +166,12 @@
unsigned bit = nr & SZLONG_MASK;
unsigned long mask;
unsigned long flags;
- unsigned long res;
+ int res;
a += nr >> SZLONG_LOG;
mask = 1UL << bit;
raw_local_irq_save(flags);
- res = (mask & *a);
+ res = (mask & *a) != 0;
*a ^= mask;
raw_local_irq_restore(flags);
return res;