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authorThomas Gleixner <tglx@linutronix.de>2008-12-17 22:34:13 +0100
committerIngo Molnar <mingo@elte.hu>2008-12-18 13:03:09 +0100
commit3d9101e92529e1ff6014f95a69afc82f37b9b13a (patch)
tree5147a9331a9a98d0ab073258d489aa0b052e524b /kernel
parent55dac3a5553b13891f0ae4bbd11920619b5436d4 (diff)
downloadlwn-3d9101e92529e1ff6014f95a69afc82f37b9b13a.tar.gz
lwn-3d9101e92529e1ff6014f95a69afc82f37b9b13a.zip
trace: fix task state printout
Impact: fix occasionally incorrect trace output The tracing code has interesting varieties of printing out task state. Unfortunalely only one of the instances is correct as it copies the code from sched.c:sched_show_task(). The others are plain wrong as they treatthe bitfield as an integer offset into the character array. Also the size check of the character array is wrong as it includes the trailing \0. Use a common state decoder inline which does the Right Thing. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/trace/trace.c39
1 files changed, 17 insertions, 22 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index d86e3252f300..803100518f11 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -1301,6 +1301,13 @@ lat_print_timestamp(struct trace_seq *s, u64 abs_usecs,
static const char state_to_char[] = TASK_STATE_TO_CHAR_STR;
+static int task_state_char(unsigned long state)
+{
+ int bit = state ? __ffs(state) + 1 : 0;
+
+ return bit < sizeof(state_to_char) - 1 ? state_to_char[bit] : '?';
+}
+
/*
* The message is supposed to contain an ending newline.
* If the printing stops prematurely, try to add a newline of our own.
@@ -1396,12 +1403,8 @@ print_lat_fmt(struct trace_iterator *iter, unsigned int trace_idx, int cpu)
trace_assign_type(field, entry);
- T = field->next_state < sizeof(state_to_char) ?
- state_to_char[field->next_state] : 'X';
-
- state = field->prev_state ?
- __ffs(field->prev_state) + 1 : 0;
- S = state < sizeof(state_to_char) - 1 ? state_to_char[state] : 'X';
+ T = task_state_char(field->next_state);
+ S = task_state_char(field->prev_state);
comm = trace_find_cmdline(field->next_pid);
trace_seq_printf(s, " %5d:%3d:%c %s [%03d] %5d:%3d:%c %s\n",
field->prev_pid,
@@ -1519,10 +1522,8 @@ static enum print_line_t print_trace_fmt(struct trace_iterator *iter)
trace_assign_type(field, entry);
- S = field->prev_state < sizeof(state_to_char) ?
- state_to_char[field->prev_state] : 'X';
- T = field->next_state < sizeof(state_to_char) ?
- state_to_char[field->next_state] : 'X';
+ T = task_state_char(field->next_state);
+ S = task_state_char(field->prev_state);
ret = trace_seq_printf(s, " %5d:%3d:%c %s [%03d] %5d:%3d:%c\n",
field->prev_pid,
field->prev_prio,
@@ -1621,12 +1622,9 @@ static enum print_line_t print_raw_fmt(struct trace_iterator *iter)
trace_assign_type(field, entry);
- S = field->prev_state < sizeof(state_to_char) ?
- state_to_char[field->prev_state] : 'X';
- T = field->next_state < sizeof(state_to_char) ?
- state_to_char[field->next_state] : 'X';
- if (entry->type == TRACE_WAKE)
- S = '+';
+ T = task_state_char(field->next_state);
+ S = entry->type == TRACE_WAKE ? '+' :
+ task_state_char(field->prev_state);
ret = trace_seq_printf(s, "%d %d %c %d %d %d %c\n",
field->prev_pid,
field->prev_prio,
@@ -1712,12 +1710,9 @@ static enum print_line_t print_hex_fmt(struct trace_iterator *iter)
trace_assign_type(field, entry);
- S = field->prev_state < sizeof(state_to_char) ?
- state_to_char[field->prev_state] : 'X';
- T = field->next_state < sizeof(state_to_char) ?
- state_to_char[field->next_state] : 'X';
- if (entry->type == TRACE_WAKE)
- S = '+';
+ T = task_state_char(field->next_state);
+ S = entry->type == TRACE_WAKE ? '+' :
+ task_state_char(field->prev_state);
SEQ_PUT_HEX_FIELD_RET(s, field->prev_pid);
SEQ_PUT_HEX_FIELD_RET(s, field->prev_prio);
SEQ_PUT_HEX_FIELD_RET(s, S);