Skip to content

Commit

Permalink
powerpc: support KASAN instrumentation of bitops
Browse files Browse the repository at this point in the history
The powerpc-specific bitops are not being picked up by the KASAN
test suite.

Instrumentation is done via the bitops/instrumented-{atomic,lock}.h
headers. They require that arch-specific versions of bitop functions
are renamed to arch_*. Do this renaming.

For clear_bit_unlock_is_negative_byte, the current implementation
uses the PG_waiters constant. This works because it's a preprocessor
macro - so it's only actually evaluated in contexts where PG_waiters
is defined. With instrumentation however, it becomes a static inline
function, and all of a sudden we need the actual value of PG_waiters.
Because of the order of header includes, it's not available and we
fail to compile. Instead, manually specify that we care about bit 7.
This is still correct: bit 7 is the bit that would mark a negative
byte.

While we're at it, replace __inline__ with inline across the file.

Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Daniel Axtens <dja@axtens.net>
Tested-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190820024941.12640-2-dja@axtens.net
  • Loading branch information
Daniel Axtens authored and Michael Ellerman committed Nov 7, 2019
1 parent 81d2c6f commit 5bece3d
Showing 1 changed file with 29 additions and 22 deletions.
51 changes: 29 additions & 22 deletions arch/powerpc/include/asm/bitops.h
Original file line number Diff line number Diff line change
Expand Up @@ -64,7 +64,7 @@

/* Macro for generating the ***_bits() functions */
#define DEFINE_BITOP(fn, op, prefix) \
static __inline__ void fn(unsigned long mask, \
static inline void fn(unsigned long mask, \
volatile unsigned long *_p) \
{ \
unsigned long old; \
Expand All @@ -86,30 +86,30 @@ DEFINE_BITOP(clear_bits, andc, "")
DEFINE_BITOP(clear_bits_unlock, andc, PPC_RELEASE_BARRIER)
DEFINE_BITOP(change_bits, xor, "")

static __inline__ void set_bit(int nr, volatile unsigned long *addr)
static inline void arch_set_bit(int nr, volatile unsigned long *addr)
{
set_bits(BIT_MASK(nr), addr + BIT_WORD(nr));
}

static __inline__ void clear_bit(int nr, volatile unsigned long *addr)
static inline void arch_clear_bit(int nr, volatile unsigned long *addr)
{
clear_bits(BIT_MASK(nr), addr + BIT_WORD(nr));
}

static __inline__ void clear_bit_unlock(int nr, volatile unsigned long *addr)
static inline void arch_clear_bit_unlock(int nr, volatile unsigned long *addr)
{
clear_bits_unlock(BIT_MASK(nr), addr + BIT_WORD(nr));
}

static __inline__ void change_bit(int nr, volatile unsigned long *addr)
static inline void arch_change_bit(int nr, volatile unsigned long *addr)
{
change_bits(BIT_MASK(nr), addr + BIT_WORD(nr));
}

/* Like DEFINE_BITOP(), with changes to the arguments to 'op' and the output
* operands. */
#define DEFINE_TESTOP(fn, op, prefix, postfix, eh) \
static __inline__ unsigned long fn( \
static inline unsigned long fn( \
unsigned long mask, \
volatile unsigned long *_p) \
{ \
Expand Down Expand Up @@ -138,34 +138,34 @@ DEFINE_TESTOP(test_and_clear_bits, andc, PPC_ATOMIC_ENTRY_BARRIER,
DEFINE_TESTOP(test_and_change_bits, xor, PPC_ATOMIC_ENTRY_BARRIER,
PPC_ATOMIC_EXIT_BARRIER, 0)

static __inline__ int test_and_set_bit(unsigned long nr,
volatile unsigned long *addr)
static inline int arch_test_and_set_bit(unsigned long nr,
volatile unsigned long *addr)
{
return test_and_set_bits(BIT_MASK(nr), addr + BIT_WORD(nr)) != 0;
}

static __inline__ int test_and_set_bit_lock(unsigned long nr,
volatile unsigned long *addr)
static inline int arch_test_and_set_bit_lock(unsigned long nr,
volatile unsigned long *addr)
{
return test_and_set_bits_lock(BIT_MASK(nr),
addr + BIT_WORD(nr)) != 0;
}

static __inline__ int test_and_clear_bit(unsigned long nr,
volatile unsigned long *addr)
static inline int arch_test_and_clear_bit(unsigned long nr,
volatile unsigned long *addr)
{
return test_and_clear_bits(BIT_MASK(nr), addr + BIT_WORD(nr)) != 0;
}

static __inline__ int test_and_change_bit(unsigned long nr,
volatile unsigned long *addr)
static inline int arch_test_and_change_bit(unsigned long nr,
volatile unsigned long *addr)
{
return test_and_change_bits(BIT_MASK(nr), addr + BIT_WORD(nr)) != 0;
}

#ifdef CONFIG_PPC64
static __inline__ unsigned long clear_bit_unlock_return_word(int nr,
volatile unsigned long *addr)
static inline unsigned long
clear_bit_unlock_return_word(int nr, volatile unsigned long *addr)
{
unsigned long old, t;
unsigned long *p = (unsigned long *)addr + BIT_WORD(nr);
Expand All @@ -185,15 +185,18 @@ static __inline__ unsigned long clear_bit_unlock_return_word(int nr,
return old;
}

/* This is a special function for mm/filemap.c */
#define clear_bit_unlock_is_negative_byte(nr, addr) \
(clear_bit_unlock_return_word(nr, addr) & BIT_MASK(PG_waiters))
/*
* This is a special function for mm/filemap.c
* Bit 7 corresponds to PG_waiters.
*/
#define arch_clear_bit_unlock_is_negative_byte(nr, addr) \
(clear_bit_unlock_return_word(nr, addr) & BIT_MASK(7))

#endif /* CONFIG_PPC64 */

#include <asm-generic/bitops/non-atomic.h>

static __inline__ void __clear_bit_unlock(int nr, volatile unsigned long *addr)
static inline void arch___clear_bit_unlock(int nr, volatile unsigned long *addr)
{
__asm__ __volatile__(PPC_RELEASE_BARRIER "" ::: "memory");
__clear_bit(nr, addr);
Expand All @@ -215,14 +218,14 @@ static __inline__ void __clear_bit_unlock(int nr, volatile unsigned long *addr)
* fls: find last (most-significant) bit set.
* Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32.
*/
static __inline__ int fls(unsigned int x)
static inline int fls(unsigned int x)
{
return 32 - __builtin_clz(x);
}

#include <asm-generic/bitops/builtin-__fls.h>

static __inline__ int fls64(__u64 x)
static inline int fls64(__u64 x)
{
return 64 - __builtin_clzll(x);
}
Expand All @@ -239,6 +242,10 @@ unsigned long __arch_hweight64(__u64 w);

#include <asm-generic/bitops/find.h>

/* wrappers that deal with KASAN instrumentation */
#include <asm-generic/bitops/instrumented-atomic.h>
#include <asm-generic/bitops/instrumented-lock.h>

/* Little-endian versions */
#include <asm-generic/bitops/le.h>

Expand Down

0 comments on commit 5bece3d

Please sign in to comment.