From a2fb3382edbea83c6f2bf6ac15e3673b2e254aad Mon Sep 17 00:00:00 2001 From: Wang Nan Date: Wed, 26 Aug 2015 10:57:46 +0000 Subject: [PATCH] tracing/uprobes: Do not print '0x (null)' when offset is 0 When manually added uprobe point with zero address, 'uprobe_events' output '(null)' instead of 0x00000000: # echo p:probe_libc/abs_0 /path/to/lib.bin:0x0 arg1=%ax > \ /sys/kernel/debug/tracing/uprobe_events # cat /sys/kernel/debug/tracing/uprobe_events p:probe_libc/abs_0 /path/to/lib.bin:0x (null) arg1=%ax This patch fixes this behavior: # cat /sys/kernel/debug/tracing/uprobe_events p:probe_libc/abs_0 /path/to/lib.bin:0x0000000000000000 Signed-off-by: Wang Nan Acked-by: Masami Hiramatsu Cc: Namhyung Kim Cc: Steven Rostedt Cc: Zefan Li Cc: pi3orama@163.com Link: http://lkml.kernel.org/r/1440586666-235233-8-git-send-email-wangnan0@huawei.com Signed-off-by: Arnaldo Carvalho de Melo --- kernel/trace/trace_uprobe.c | 17 ++++++++++++++++- 1 file changed, 16 insertions(+), 1 deletion(-) diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c index f97479f1ce35..d2f6d0be3503 100644 --- a/kernel/trace/trace_uprobe.c +++ b/kernel/trace/trace_uprobe.c @@ -601,7 +601,22 @@ static int probes_seq_show(struct seq_file *m, void *v) seq_printf(m, "%c:%s/%s", c, tu->tp.call.class->system, trace_event_name(&tu->tp.call)); - seq_printf(m, " %s:0x%p", tu->filename, (void *)tu->offset); + seq_printf(m, " %s:", tu->filename); + + /* Don't print "0x (null)" when offset is 0 */ + if (tu->offset) { + seq_printf(m, "0x%p", (void *)tu->offset); + } else { + switch (sizeof(void *)) { + case 4: + seq_printf(m, "0x00000000"); + break; + case 8: + default: + seq_printf(m, "0x0000000000000000"); + break; + } + } for (i = 0; i < tu->tp.nr_args; i++) seq_printf(m, " %s=%s", tu->tp.args[i].name, tu->tp.args[i].comm); -- 2.39.5