| From | Kamal Mostafa <> | Subject | [PATCH 3.13 137/259] tracing: Add ftrace_trace_stack into __trace_puts/__trace_bputs | Date | Fri, 8 Aug 2014 13:39:20 -0700 |
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3.13.11.6 -stable review patch. If anyone has any objections, please let me know.
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From: "zhangwei(Jovi)" <jovi.zhangwei@huawei.com>
commit 8abfb8727f4a724d31f9ccfd8013fbd16d539445 upstream.
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/51E7A7C9.9040401@huawei.com
Signed-off-by: zhangwei(Jovi) <jovi.zhangwei@huawei.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Kamal Mostafa <kamal@canonical.com> --- 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 9250479..d3db296 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -454,6 +454,9 @@ 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; @@ -463,7 +466,7 @@ 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; @@ -480,6 +483,7 @@ 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; } @@ -497,6 +501,9 @@ 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; @@ -504,7 +511,7 @@ 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; @@ -513,6 +520,7 @@ 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; } -- 1.9.1
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