1 files changed, 25 insertions, 93 deletions

diff --git a/kernel/debug/kdb/kdb_support.c b/kernel/debug/kdb/kdb_support.c
index 7507d9a8dc6a..df2bface866e 100644
--- a/kernel/debug/kdb/kdb_support.c
+++ b/kernel/debug/kdb/kdb_support.c
@@ -24,6 +24,7 @@
 #include <linux/uaccess.h>
 #include <linux/kdb.h>
 #include <linux/slab.h>
+#include <linux/ctype.h>
 #include "kdb_private.h"
 
 /*
@@ -473,82 +474,7 @@ int kdb_putword(unsigned long addr, unsigned long word, size_t size)
 	return diag;
 }
 
-/*
- * kdb_task_state_string - Convert a string containing any of the
- *	letters DRSTCZEUIMA to a mask for the process state field and
- *	return the value.  If no argument is supplied, return the mask
- *	that corresponds to environment variable PS, DRSTCZEU by
- *	default.
- * Inputs:
- *	s	String to convert
- * Returns:
- *	Mask for process state.
- * Notes:
- *	The mask folds data from several sources into a single long value, so
- *	be careful not to overlap the bits.  TASK_* bits are in the LSB,
- *	special cases like UNRUNNABLE are in the MSB.  As of 2.6.10-rc1 there
- *	is no overlap between TASK_* and EXIT_* but that may not always be
- *	true, so EXIT_* bits are shifted left 16 bits before being stored in
- *	the mask.
- */
-
-/* unrunnable is < 0 */
-#define UNRUNNABLE	(1UL << (8*sizeof(unsigned long) - 1))
-#define RUNNING		(1UL << (8*sizeof(unsigned long) - 2))
-#define IDLE		(1UL << (8*sizeof(unsigned long) - 3))
-#define DAEMON		(1UL << (8*sizeof(unsigned long) - 4))
 
-unsigned long kdb_task_state_string(const char *s)
-{
-	long res = 0;
-	if (!s) {
-		s = kdbgetenv("PS");
-		if (!s)
-			s = "DRSTCZEU";	/* default value for ps */
-	}
-	while (*s) {
-		switch (*s) {
-		case 'D':
-			res |= TASK_UNINTERRUPTIBLE;
-			break;
-		case 'R':
-			res |= RUNNING;
-			break;
-		case 'S':
-			res |= TASK_INTERRUPTIBLE;
-			break;
-		case 'T':
-			res |= TASK_STOPPED;
-			break;
-		case 'C':
-			res |= TASK_TRACED;
-			break;
-		case 'Z':
-			res |= EXIT_ZOMBIE << 16;
-			break;
-		case 'E':
-			res |= EXIT_DEAD << 16;
-			break;
-		case 'U':
-			res |= UNRUNNABLE;
-			break;
-		case 'I':
-			res |= IDLE;
-			break;
-		case 'M':
-			res |= DAEMON;
-			break;
-		case 'A':
-			res = ~0UL;
-			break;
-		default:
-			  kdb_func_printf("unknown flag '%c' ignored\n", *s);
-			  break;
-		}
-		++s;
-	}
-	return res;
-}
 
 /*
  * kdb_task_state_char - Return the character that represents the task state.
@@ -559,7 +485,6 @@ unsigned long kdb_task_state_string(const char *s)
  */
 char kdb_task_state_char (const struct task_struct *p)
 {
-	unsigned int p_state;
 	unsigned long tmp;
 	char state;
 	int cpu;
@@ -568,25 +493,18 @@ char kdb_task_state_char (const struct task_struct *p)
 	    copy_from_kernel_nofault(&tmp, (char *)p, sizeof(unsigned long)))
 		return 'E';
 
-	cpu = kdb_process_cpu(p);
-	p_state = READ_ONCE(p->__state);
-	state = (p_state == 0) ? 'R' :
-		(p_state < 0) ? 'U' :
-		(p_state & TASK_UNINTERRUPTIBLE) ? 'D' :
-		(p_state & TASK_STOPPED) ? 'T' :
-		(p_state & TASK_TRACED) ? 'C' :
-		(p->exit_state & EXIT_ZOMBIE) ? 'Z' :
-		(p->exit_state & EXIT_DEAD) ? 'E' :
-		(p_state & TASK_INTERRUPTIBLE) ? 'S' : '?';
+	state = task_state_to_char((struct task_struct *) p);
+
 	if (is_idle_task(p)) {
 		/* Idle task.  Is it really idle, apart from the kdb
 		 * interrupt? */
+		cpu = kdb_process_cpu(p);
 		if (!kdb_task_has_cpu(p) || kgdb_info[cpu].irq_depth == 1) {
 			if (cpu != kdb_initial_cpu)
-				state = 'I';	/* idle task */
+				state = '-';	/* idle task */
 		}
-	} else if (!p->mm && state == 'S') {
-		state = 'M';	/* sleeping system daemon */
+	} else if (!p->mm && strchr("IMS", state)) {
+		state = tolower(state);		/* sleeping system daemon */
 	}
 	return state;
 }
@@ -596,14 +514,28 @@ char kdb_task_state_char (const struct task_struct *p)
  *	given by the mask.
  * Inputs:
  *	p	struct task for the process
- *	mask	mask from kdb_task_state_string to select processes
+ *	mask	set of characters used to select processes; both NULL
+ *	        and the empty string mean adopt a default filter, which
+ *	        is to suppress sleeping system daemons and the idle tasks
  * Returns:
  *	True if the process matches at least one criteria defined by the mask.
  */
-unsigned long kdb_task_state(const struct task_struct *p, unsigned long mask)
+bool kdb_task_state(const struct task_struct *p, const char *mask)
 {
-	char state[] = { kdb_task_state_char(p), '\0' };
-	return (mask & kdb_task_state_string(state)) != 0;
+	char state = kdb_task_state_char(p);
+
+	/* If there is no mask, then we will filter code that runs when the
+	 * scheduler is idling and any system daemons that are currently
+	 * sleeping.
+	 */
+	if (!mask || mask[0] == '\0')
+		return !strchr("-ims", state);
+
+	/* A is a special case that matches all states */
+	if (strchr(mask, 'A'))
+		return true;
+
+	return strchr(mask, state);
 }
 
 /* Maintain a small stack of kdb_flags to allow recursion without disturbing