When using multiple calls to __print_symbolic and __print_flags in the same tracer, I noticed that the output was incorrect. I think the following patch is the correct fix (it works for me) but please check it carefully since I'm not that familiar with this code, and I may well have made a mistake somewhere.
The patch is vs. the latest -tip tree which doesn't yet seem to contain the EXPORT_SYMBOL() fix that I sent earlier. Signed-off-by: Steven Whitehouse <[email protected]> diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c index c12d95d..ac6ced1 100644 --- a/kernel/trace/trace_output.c +++ b/kernel/trace/trace_output.c @@ -222,10 +222,9 @@ ftrace_print_flags_seq(struct trace_seq *p, const char *delim, { unsigned long mask; const char *str; + const char *ret = p->buffer + p->len; int i; - trace_seq_init(p); - for (i = 0; flag_array[i].name && flags; i++) { mask = flag_array[i].mask; @@ -248,7 +247,7 @@ ftrace_print_flags_seq(struct trace_seq *p, const char *delim, trace_seq_putc(p, 0); - return p->buffer; + return ret; } const char * @@ -256,8 +255,7 @@ ftrace_print_symbols_seq(struct trace_seq *p, unsigned long val, const struct trace_print_flags *symbol_array) { int i; - - trace_seq_init(p); + const char *ret = p->buffer + p->len; for (i = 0; symbol_array[i].name; i++) { @@ -273,7 +271,7 @@ ftrace_print_symbols_seq(struct trace_seq *p, unsigned long val, trace_seq_putc(p, 0); - return p->buffer; + return ret; } #ifdef CONFIG_KRETPROBES
