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yaml
---
r: 139047
b: refs/heads/master
c: 4f367d8
h: refs/heads/master
i:
  139045: 3d826ac
  139043: 5a1c27c
  139039: 6b126fa
v: v3
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Peter Zijlstra authored and Ingo Molnar committed Feb 14, 2009
1 parent 1b7c293 commit f8c5a58
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Showing 2 changed files with 62 additions and 94 deletions.
2 changes: 1 addition & 1 deletion [refs]
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Original file line number Diff line number Diff line change
@@ -1,2 +1,2 @@
---
refs/heads/master: f510b233cfc7bfd57b6007071c52aa42e3d16b06
refs/heads/master: 4f367d8adca947bed4385740a13d1efb1a06fba1
154 changes: 61 additions & 93 deletions trunk/kernel/lockdep.c
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Original file line number Diff line number Diff line change
Expand Up @@ -1268,68 +1268,84 @@ check_usage(struct task_struct *curr, struct held_lock *prev,
bit_backwards, bit_forwards, irqclass);
}

static int
check_prev_add_irq(struct task_struct *curr, struct held_lock *prev,
struct held_lock *next)
static const char *state_names[] = {
#define LOCKDEP_STATE(__STATE) \
STR(__STATE),
#include "lockdep_states.h"
#undef LOCKDEP_STATE
};

static const char *state_rnames[] = {
#define LOCKDEP_STATE(__STATE) \
STR(__STATE)"-READ",
#include "lockdep_states.h"
#undef LOCKDEP_STATE
};

static inline const char *state_name(enum lock_usage_bit bit)
{
/*
* Prove that the new dependency does not connect a hardirq-safe
* lock with a hardirq-unsafe lock - to achieve this we search
* the backwards-subgraph starting at <prev>, and the
* forwards-subgraph starting at <next>:
*/
if (!check_usage(curr, prev, next, LOCK_USED_IN_HARDIRQ,
LOCK_ENABLED_HARDIRQ, "hard"))
return 0;
return (bit & 1) ? state_rnames[bit >> 2] : state_names[bit >> 2];
}

static int exclusive_bit(int new_bit)
{
/*
* Prove that the new dependency does not connect a hardirq-safe-read
* lock with a hardirq-unsafe lock - to achieve this we search
* the backwards-subgraph starting at <prev>, and the
* forwards-subgraph starting at <next>:
* USED_IN
* USED_IN_READ
* ENABLED
* ENABLED_READ
*
* bit 0 - write/read
* bit 1 - used_in/enabled
* bit 2+ state
*/
if (!check_usage(curr, prev, next, LOCK_USED_IN_HARDIRQ_READ,
LOCK_ENABLED_HARDIRQ, "hard-read"))
return 0;

int state = new_bit & ~3;
int dir = new_bit & 2;

/*
* Prove that the new dependency does not connect a softirq-safe
* lock with a softirq-unsafe lock - to achieve this we search
* the backwards-subgraph starting at <prev>, and the
* forwards-subgraph starting at <next>:
* keep state, bit flip the direction and strip read.
*/
if (!check_usage(curr, prev, next, LOCK_USED_IN_SOFTIRQ,
LOCK_ENABLED_SOFTIRQ, "soft"))
return 0;
return state | (dir ^ 2);
}

static int check_irq_usage(struct task_struct *curr, struct held_lock *prev,
struct held_lock *next, enum lock_usage_bit bit)
{
/*
* Prove that the new dependency does not connect a softirq-safe-read
* lock with a softirq-unsafe lock - to achieve this we search
* Prove that the new dependency does not connect a hardirq-safe
* lock with a hardirq-unsafe lock - to achieve this we search
* the backwards-subgraph starting at <prev>, and the
* forwards-subgraph starting at <next>:
*/
if (!check_usage(curr, prev, next, LOCK_USED_IN_SOFTIRQ_READ,
LOCK_ENABLED_SOFTIRQ, "soft"))
if (!check_usage(curr, prev, next, bit,
exclusive_bit(bit), state_name(bit)))
return 0;

bit++; /* _READ */

/*
* Prove that the new dependency does not connect a reclaim-fs-safe
* lock with a reclaim-fs-unsafe lock - to achieve this we search
* Prove that the new dependency does not connect a hardirq-safe-read
* lock with a hardirq-unsafe lock - to achieve this we search
* the backwards-subgraph starting at <prev>, and the
* forwards-subgraph starting at <next>:
*/
if (!check_usage(curr, prev, next, LOCK_USED_IN_RECLAIM_FS,
LOCK_ENABLED_RECLAIM_FS, "reclaim-fs"))
if (!check_usage(curr, prev, next, bit,
exclusive_bit(bit), state_name(bit)))
return 0;

/*
* Prove that the new dependency does not connect a reclaim-fs-safe-read
* lock with a reclaim-fs-unsafe lock - to achieve this we search
* the backwards-subgraph starting at <prev>, and the
* forwards-subgraph starting at <next>:
*/
if (!check_usage(curr, prev, next, LOCK_USED_IN_RECLAIM_FS_READ,
LOCK_ENABLED_RECLAIM_FS, "reclaim-fs-read"))
return 1;
}

static int
check_prev_add_irq(struct task_struct *curr, struct held_lock *prev,
struct held_lock *next)
{
#define LOCKDEP_STATE(__STATE) \
if (!check_irq_usage(curr, prev, next, LOCK_USED_IN_##__STATE)) \
return 0;
#include "lockdep_states.h"
#undef LOCKDEP_STATE

return 1;
}
Expand Down Expand Up @@ -1984,30 +2000,6 @@ static int RECLAIM_FS_verbose(struct lock_class *class)

#define STRICT_READ_CHECKS 1

static const char *state_names[] = {
#define LOCKDEP_STATE(__STATE) \
STR(__STATE),
#include "lockdep_states.h"
#undef LOCKDEP_STATE
};

static inline const char *state_name(enum lock_usage_bit bit)
{
return state_names[bit >> 2];
}

static const char *state_rnames[] = {
#define LOCKDEP_STATE(__STATE) \
STR(__STATE)"-READ",
#include "lockdep_states.h"
#undef LOCKDEP_STATE
};

static inline const char *state_rname(enum lock_usage_bit bit)
{
return state_rnames[bit >> 2];
}

static int (*state_verbose_f[])(struct lock_class *class) = {
#define LOCKDEP_STATE(__STATE) \
__STATE##_verbose,
Expand All @@ -2021,37 +2013,12 @@ static inline int state_verbose(enum lock_usage_bit bit,
return state_verbose_f[bit >> 2](class);
}

static int exclusive_bit(int new_bit)
{
/*
* USED_IN
* USED_IN_READ
* ENABLED
* ENABLED_READ
*
* bit 0 - write/read
* bit 1 - used_in/enabled
* bit 2+ state
*/

int state = new_bit & ~3;
int dir = new_bit & 2;

/*
* keep state, bit flip the direction and strip read.
*/
return state | (dir ^ 2);
}

typedef int (*check_usage_f)(struct task_struct *, struct held_lock *,
enum lock_usage_bit bit, const char *name);

static int
mark_lock_irq(struct task_struct *curr, struct held_lock *this, int new_bit)
{
const char *name = state_name(new_bit);
const char *rname = state_rname(new_bit);

int excl_bit = exclusive_bit(new_bit);
int read = new_bit & 1;
int dir = new_bit & 2;
Expand All @@ -2078,7 +2045,7 @@ mark_lock_irq(struct task_struct *curr, struct held_lock *this, int new_bit)
* states.
*/
if ((!read || !dir || STRICT_READ_CHECKS) &&
!usage(curr, this, excl_bit, name))
!usage(curr, this, excl_bit, state_name(new_bit)))
return 0;

/*
Expand All @@ -2089,7 +2056,8 @@ mark_lock_irq(struct task_struct *curr, struct held_lock *this, int new_bit)
return 0;

if (STRICT_READ_CHECKS &&
!usage(curr, this, excl_bit + 1, rname))
!usage(curr, this, excl_bit + 1,
state_name(new_bit + 1)))
return 0;
}

Expand Down

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