From 3d9101e92529e1ff6014f95a69afc82f37b9b13a Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Wed, 17 Dec 2008 22:34:13 +0100 Subject: [PATCH] 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 Acked-by: Steven Rostedt Signed-off-by: Ingo Molnar --- kernel/trace/trace.c | 39 +++++++++++++++++---------------------- 1 file changed, 17 insertions(+), 22 deletions(-) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index d86e3252f30..803100518f1 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);