[PATCH resend 0/8] liblockdep fixes for 3.8

[PATCH resend 0/8] liblockdep fixes for 3.8

[Levin, Alexander]

Hi Ingo,

A bunch of fixes that I dropped the ball on back in 3.7.

Mostly compilation fixes for errors that have happened
due to changes on the kernel side in 3.7.

Ben Hutchings (7):
  liblockdep: Fix undefined symbol prandom_u32
  liblockdep: Reduce MAX_LOCK_DEPTH to avoid overflowing
    lock_chain::depth
  liblockdep: Define the ARRAY_SIZE() macro
  liblockdep: Enable -Wall by default
  liblockdep: Fix 'unused value' warnings
  liblockdep: Fix 'set but not used' warnings
  liblockdep: Fix 'defined but not used' warning for init_utsname()

Vishal Thanki (1):
  liblockdep: Remove -lpthread compiler option

 tools/lib/lockdep/Makefile                     |  1 +
 tools/lib/lockdep/lockdep.c                    | 17 +++++++++++++++++
 tools/lib/lockdep/run_tests.sh                 |  4 ++--
 tools/lib/lockdep/uinclude/linux/debug_locks.h |  2 +-
 tools/lib/lockdep/uinclude/linux/irqflags.h    |  8 ++++----
 tools/lib/lockdep/uinclude/linux/kernel.h      | 14 +++++++++++---
 tools/lib/lockdep/uinclude/linux/lockdep.h     | 18 ++++++------------
 7 files changed, 42 insertions(+), 22 deletions(-)

-- 
2.7.4

[PATCH 1/8] liblockdep: Fix undefined symbol prandom_u32

[Levin, Alexander]

From: Ben Hutchings <ben@decadent.org.uk>

__lock_pin_lock() now calls prandom_u32() which is not defined in
liblockdep.  __lock_pin_lock() and its caller lock_pin_lock() are dead
code in liblockdep, but we still need to provide a definition of
prandom_u32() in case lazy binding is disabled.

Fixes: e7904a28f533 ("locking/lockdep, sched/core: Implement a better ...")
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
---
 tools/lib/lockdep/lockdep.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/tools/lib/lockdep/lockdep.c b/tools/lib/lockdep/lockdep.c
index a0a2e3a..443acb1 100644
--- a/tools/lib/lockdep/lockdep.c
+++ b/tools/lib/lockdep/lockdep.c
@@ -1,8 +1,15 @@
 #include <linux/lockdep.h>
+#include <stdlib.h>
 
 /* Trivial API wrappers, we don't (yet) have RCU in user-space: */
 #define hlist_for_each_entry_rcu	hlist_for_each_entry
 #define hlist_add_head_rcu		hlist_add_head
 #define hlist_del_rcu			hlist_del
 
+u32 prandom_u32(void)
+{
+	/* Used only by lock_pin_lock() which is dead code */
+	abort();
+}
+
 #include "../../../kernel/locking/lockdep.c"
-- 
2.7.4

[PATCH 4/8] liblockdep: Enable -Wall by default

[Levin, Alexander]

From: Ben Hutchings <ben@decadent.org.uk>

Regressions in liblockdep may be missed because it doesn't enable
warnings.

Adding -Wall immediately introduces a lot of warnings, but those will
be fixed by the following commits.

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
---
 tools/lib/lockdep/Makefile | 1 +
 1 file changed, 1 insertion(+)

diff --git a/tools/lib/lockdep/Makefile b/tools/lib/lockdep/Makefile
index 1d57af5..710a0ed 100644
--- a/tools/lib/lockdep/Makefile
+++ b/tools/lib/lockdep/Makefile
@@ -79,6 +79,7 @@ INCLUDES = -I. -I./uinclude -I./include -I../../include $(CONFIG_INCLUDES)
 # Set compile option CFLAGS if not set elsewhere
 CFLAGS ?= -g -DCONFIG_LOCKDEP -DCONFIG_STACKTRACE -DCONFIG_PROVE_LOCKING -DBITS_PER_LONG=__WORDSIZE -DLIBLOCKDEP_VERSION='"$(LIBLOCKDEP_VERSION)"' -rdynamic -O0 -g
 CFLAGS += -fPIC
+CFLAGS += -Wall
 
 override CFLAGS += $(CONFIG_FLAGS) $(INCLUDES) $(PLUGIN_DIR_SQ)
 
-- 
2.7.4

[PATCH 2/8] liblockdep: Reduce MAX_LOCK_DEPTH to avoid overflowing lock_chain::depth

[Levin, Alexander]

From: Ben Hutchings <ben@decadent.org.uk>

liblockdep has been broken since commit 75dd602a5198 ("lockdep: Fix
lock_chain::base size"), as that adds a check that MAX_LOCK_DEPTH is
within the range of lock_chain::depth and in liblockdep it is much
too large.

That should have resulted in a compiler error, but didn't because:

- the check uses ARRAY_SIZE(), which isn't yet defined in liblockdep
  so is assumed to be an (undeclared) function
- putting a function call inside a BUILD_BUG_ON() expression quietly
  turns it into some nonsense involving a variable-length array

It did produce a compiler warning, but I didn't notice because
liblockdep already produces too many warnings if -Wall is enabled
(which I'll fix shortly).

Even before that commit, which reduced lock_chain::depth from 8 bits
to 6, MAX_LOCK_DEPTH was too large.

Cc: <stable@vger.kernel.org> # for versions before 4.6, use a value of 255
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
---
 tools/lib/lockdep/uinclude/linux/lockdep.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/lib/lockdep/uinclude/linux/lockdep.h b/tools/lib/lockdep/uinclude/linux/lockdep.h
index c808c7d..d302142 100644
--- a/tools/lib/lockdep/uinclude/linux/lockdep.h
+++ b/tools/lib/lockdep/uinclude/linux/lockdep.h
@@ -8,7 +8,7 @@
 #include <linux/utsname.h>
 #include <linux/compiler.h>
 
-#define MAX_LOCK_DEPTH 2000UL
+#define MAX_LOCK_DEPTH 63UL
 
 #define asmlinkage
 #define __visible
-- 
2.7.4

[PATCH 3/8] liblockdep: Define the ARRAY_SIZE() macro

[Levin, Alexander]

From: Ben Hutchings <ben@decadent.org.uk>

lockdep.c now uses ARRAY_SIZE().

Fixes: 75dd602a5198 ("lockdep: Fix lock_chain::base size")
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
---
 tools/lib/lockdep/uinclude/linux/kernel.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/tools/lib/lockdep/uinclude/linux/kernel.h b/tools/lib/lockdep/uinclude/linux/kernel.h
index 276c7a8..da87bd9 100644
--- a/tools/lib/lockdep/uinclude/linux/kernel.h
+++ b/tools/lib/lockdep/uinclude/linux/kernel.h
@@ -7,6 +7,8 @@
 #include <linux/hardirq.h>
 #include <linux/kern_levels.h>
 
+#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]))
+
 #ifndef container_of
 #define container_of(ptr, type, member) ({			\
 	const typeof(((type *)0)->member) * __mptr = (ptr);	\
-- 
2.7.4

[PATCH 6/8] liblockdep: Fix 'set but not used' warnings

[Levin, Alexander]

From: Ben Hutchings <ben@decadent.org.uk>

liblockdep defines trivial macros for working with interrupt flags, as
interrupts are never disabled in userland.  This results in warnings
from gcc when -Wunused-but-set-variable is enabled, and it is enabled
by -Wall.  Fix this by evaluating the flags parameter and casting it to
void.

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
---
 tools/lib/lockdep/uinclude/linux/irqflags.h | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/tools/lib/lockdep/uinclude/linux/irqflags.h b/tools/lib/lockdep/uinclude/linux/irqflags.h
index 6cc296f..df77669 100644
--- a/tools/lib/lockdep/uinclude/linux/irqflags.h
+++ b/tools/lib/lockdep/uinclude/linux/irqflags.h
@@ -17,19 +17,19 @@
 #define raw_local_irq_disable() do { } while (0)
 #define raw_local_irq_enable() do { } while (0)
 #define raw_local_irq_save(flags) ((flags) = 0)
-#define raw_local_irq_restore(flags) do { } while (0)
+#define raw_local_irq_restore(flags) ((void)(flags))
 #define raw_local_save_flags(flags) ((flags) = 0)
-#define raw_irqs_disabled_flags(flags) do { } while (0)
+#define raw_irqs_disabled_flags(flags) ((void)(flags))
 #define raw_irqs_disabled() 0
 #define raw_safe_halt()
 
 #define local_irq_enable() do { } while (0)
 #define local_irq_disable() do { } while (0)
 #define local_irq_save(flags) ((flags) = 0)
-#define local_irq_restore(flags) do { } while (0)
+#define local_irq_restore(flags) ((void)(flags))
 #define local_save_flags(flags)	((flags) = 0)
 #define irqs_disabled() (1)
-#define irqs_disabled_flags(flags) (0)
+#define irqs_disabled_flags(flags) ((void)(flags), 0)
 #define safe_halt() do { } while (0)
 
 #define trace_lock_release(x, y)
-- 
2.7.4

[PATCH 5/8] liblockdep: Fix 'unused value' warnings

[Levin, Alexander]

From: Ben Hutchings <ben@decadent.org.uk>

liblockdep defines various macros that may expand to an expression
with no effect, while the in-kernel definition does have an effect.
This results in warnings from gcc when -Wunused-value is enabled, and
is is enabled by -Wall.  Fix this by introducing trivial functions,
as function return values are generally allowed to be ignored.

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
---
 tools/lib/lockdep/uinclude/linux/debug_locks.h |  2 +-
 tools/lib/lockdep/uinclude/linux/kernel.h      | 12 +++++++++---
 tools/lib/lockdep/uinclude/linux/lockdep.h     |  6 +++++-
 3 files changed, 15 insertions(+), 5 deletions(-)

diff --git a/tools/lib/lockdep/uinclude/linux/debug_locks.h b/tools/lib/lockdep/uinclude/linux/debug_locks.h
index f38eb64..1d4fbec 100644
--- a/tools/lib/lockdep/uinclude/linux/debug_locks.h
+++ b/tools/lib/lockdep/uinclude/linux/debug_locks.h
@@ -4,7 +4,7 @@
 #include <stddef.h>
 #include <linux/compiler.h>
 
-#define DEBUG_LOCKS_WARN_ON(x) (x)
+#define DEBUG_LOCKS_WARN_ON(x) WARN_ON(x)
 
 extern bool debug_locks;
 extern bool debug_locks_silent;
diff --git a/tools/lib/lockdep/uinclude/linux/kernel.h b/tools/lib/lockdep/uinclude/linux/kernel.h
index da87bd9..021cff4 100644
--- a/tools/lib/lockdep/uinclude/linux/kernel.h
+++ b/tools/lib/lockdep/uinclude/linux/kernel.h
@@ -22,10 +22,16 @@
 	_max1 > _max2 ? _max1 : _max2; })
 
 #define BUILD_BUG_ON(condition) ((void)sizeof(char[1 - 2*!!(condition)]))
-#define WARN_ON(x) (x)
-#define WARN_ON_ONCE(x) (x)
+
+static inline int lockdep_warn(int condition)
+{
+	return condition;
+}
+#define WARN_ON(x) lockdep_warn(x)
+#define WARN_ON_ONCE(x) WARN_ON(x)
+#define WARN(x, y...) WARN_ON(x)
+
 #define likely(x) (x)
-#define WARN(x, y...) (x)
 #define uninitialized_var(x) x
 #define __init
 #define noinline
diff --git a/tools/lib/lockdep/uinclude/linux/lockdep.h b/tools/lib/lockdep/uinclude/linux/lockdep.h
index d302142..d107903 100644
--- a/tools/lib/lockdep/uinclude/linux/lockdep.h
+++ b/tools/lib/lockdep/uinclude/linux/lockdep.h
@@ -29,7 +29,11 @@ extern struct task_struct *__curr(void);
 
 #define current (__curr())
 
-#define debug_locks_off() 1
+static inline int debug_locks_off(void)
+{
+	return 1;
+}
+
 #define task_pid_nr(tsk) ((tsk)->pid)
 
 #define KSYM_NAME_LEN 128
-- 
2.7.4

[PATCH 7/8] liblockdep: Fix 'defined but not used' warning for init_utsname()

[Levin, Alexander]

From: Ben Hutchings <ben@decadent.org.uk>

We define init_utsname() as static but not inline, resulting
in a warning for every source file that includes lockdep.h but
doesn't call it.

Since it is only used by lockdep.c, define it in there.

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
---
 tools/lib/lockdep/lockdep.c                | 10 ++++++++++
 tools/lib/lockdep/uinclude/linux/lockdep.h | 10 ----------
 2 files changed, 10 insertions(+), 10 deletions(-)

diff --git a/tools/lib/lockdep/lockdep.c b/tools/lib/lockdep/lockdep.c
index 443acb1..209f967 100644
--- a/tools/lib/lockdep/lockdep.c
+++ b/tools/lib/lockdep/lockdep.c
@@ -12,4 +12,14 @@ u32 prandom_u32(void)
 	abort();
 }
 
+static struct new_utsname *init_utsname(void)
+{
+	static struct new_utsname n = (struct new_utsname) {
+		.release = "liblockdep",
+		.version = LIBLOCKDEP_VERSION,
+	};
+
+	return &n;
+}
+
 #include "../../../kernel/locking/lockdep.c"
diff --git a/tools/lib/lockdep/uinclude/linux/lockdep.h b/tools/lib/lockdep/uinclude/linux/lockdep.h
index d107903..c157242 100644
--- a/tools/lib/lockdep/uinclude/linux/lockdep.h
+++ b/tools/lib/lockdep/uinclude/linux/lockdep.h
@@ -44,16 +44,6 @@ static inline int debug_locks_off(void)
 #define atomic_t unsigned long
 #define atomic_inc(x) ((*(x))++)
 
-static struct new_utsname *init_utsname(void)
-{
-	static struct new_utsname n = (struct new_utsname) {
-		.release = "liblockdep",
-		.version = LIBLOCKDEP_VERSION,
-	};
-
-	return &n;
-}
-
 #define print_tainted() ""
 #define static_obj(x) 1
 
-- 
2.7.4

[PATCH 8/8] liblockdep: Remove -lpthread compiler option

[Levin, Alexander]

From: Vishal Thanki <vishalthanki@gmail.com>

With -lpthread option, the test for ABBA_2threads was
failing, and test passed if it was removed.
Since -pthread compiler option is sufficient for linking
to pthread libraries, this patch removes -lpthread.

Signed-off-by: Vishal Thanki <vishalthanki@gmail.com>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
---
 tools/lib/lockdep/run_tests.sh | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/tools/lib/lockdep/run_tests.sh b/tools/lib/lockdep/run_tests.sh
index 1069d96..3fd297b 100755
--- a/tools/lib/lockdep/run_tests.sh
+++ b/tools/lib/lockdep/run_tests.sh
@@ -4,7 +4,7 @@ make &> /dev/null
 
 for i in `ls tests/*.c`; do
 	testname=$(basename "$i" .c)
-	gcc -o tests/$testname -pthread -lpthread $i liblockdep.a -Iinclude -D__USE_LIBLOCKDEP &> /dev/null
+	gcc -o tests/$testname -pthread $i liblockdep.a -Iinclude -D__USE_LIBLOCKDEP &> /dev/null
 	echo -ne "$testname... "
 	if [ $(timeout 1 ./tests/$testname | wc -l) -gt 0 ]; then
 		echo "PASSED!"
@@ -18,7 +18,7 @@ done
 
 for i in `ls tests/*.c`; do
 	testname=$(basename "$i" .c)
-	gcc -o tests/$testname -pthread -lpthread -Iinclude $i &> /dev/null
+	gcc -o tests/$testname -pthread -Iinclude $i &> /dev/null
 	echo -ne "(PRELOAD) $testname... "
 	if [ $(timeout 1 ./lockdep ./tests/$testname | wc -l) -gt 0 ]; then
 		echo "PASSED!"
-- 
2.7.4