From: "zhangwei(Jovi)" <jovi.zhang...@huawei.com> Currently trace option stacktrace is not applicable for trace_printk with constant string argument, the reason is in __trace_puts/__trace_bputs ftrace_trace_stack is missing.
In contrast, when using trace_printk with non constant string argument(will call into __trace_printk/__trace_bprintk), then trace option stacktrace is workable, this inconstant result will confuses users a lot. Link: http://lkml.kernel.org/p/51e7a7c9.9040...@huawei.com Cc: sta...@vger.kernel.org # 3.10+ Signed-off-by: zhangwei(Jovi) <jovi.zhang...@huawei.com> Signed-off-by: Steven Rostedt <rost...@goodmis.org> --- kernel/trace/trace.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index f243444a3772..a6ffc8918dda 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -466,6 +466,9 @@ int __trace_puts(unsigned long ip, const char *str, int size) struct print_entry *entry; unsigned long irq_flags; int alloc; + int pc; + + pc = preempt_count(); if (unlikely(tracing_selftest_running || tracing_disabled)) return 0; @@ -475,7 +478,7 @@ int __trace_puts(unsigned long ip, const char *str, int size) local_save_flags(irq_flags); buffer = global_trace.trace_buffer.buffer; event = trace_buffer_lock_reserve(buffer, TRACE_PRINT, alloc, - irq_flags, preempt_count()); + irq_flags, pc); if (!event) return 0; @@ -492,6 +495,7 @@ int __trace_puts(unsigned long ip, const char *str, int size) entry->buf[size] = '\0'; __buffer_unlock_commit(buffer, event); + ftrace_trace_stack(buffer, irq_flags, 4, pc); return size; } @@ -509,6 +513,9 @@ int __trace_bputs(unsigned long ip, const char *str) struct bputs_entry *entry; unsigned long irq_flags; int size = sizeof(struct bputs_entry); + int pc; + + pc = preempt_count(); if (unlikely(tracing_selftest_running || tracing_disabled)) return 0; @@ -516,7 +523,7 @@ int __trace_bputs(unsigned long ip, const char *str) local_save_flags(irq_flags); buffer = global_trace.trace_buffer.buffer; event = trace_buffer_lock_reserve(buffer, TRACE_BPUTS, size, - irq_flags, preempt_count()); + irq_flags, pc); if (!event) return 0; @@ -525,6 +532,7 @@ int __trace_bputs(unsigned long ip, const char *str) entry->str = str; __buffer_unlock_commit(buffer, event); + ftrace_trace_stack(buffer, irq_flags, 4, pc); return 1; } -- 2.0.0 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
