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| author | Zheng Yejian <zhengyejian1@huawei.com> | 2022-10-11 12:03:52 +0000 |
|---|---|---|
| committer | Steven Rostedt (Google) <rostedt@goodmis.org> | 2022-10-12 07:05:47 -0400 |
| commit | 30f7d1cac2aab8fec560a388ad31ca5e5d04a822 (patch) | |
| tree | cc10eac59bb68a30e9bec297c6ddfc12150fc6ce /kernel/trace/ftrace.c | |
| parent | 4f881a696484a7d31a4d1b12547615b1a3ee5771 (diff) | |
| download | linux-30f7d1cac2aab8fec560a388ad31ca5e5d04a822.tar.bz2 | |
ftrace: Fix char print issue in print_ip_ins()
When ftrace bug happened, following log shows every hex data in
problematic ip address:
actual: ffffffe8:6b:ffffffd9:01:21
But so many 'f's seem a little confusing, and that is because format
'%x' being used to print signed chars in array 'ins'. As suggested
by Joe, change to use format "%*phC" to print array 'ins'.
After this patch, the log is like:
actual: e8:6b:d9:01:21
Link: https://lkml.kernel.org/r/20221011120352.1878494-1-zhengyejian1@huawei.com
Fixes: 6c14133d2d3f ("ftrace: Do not blindly read the ip address in ftrace_bug()")
Suggested-by: Joe Perches <joe@perches.com>
Signed-off-by: Zheng Yejian <zhengyejian1@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Diffstat (limited to 'kernel/trace/ftrace.c')
| -rw-r--r-- | kernel/trace/ftrace.c | 5 |
1 files changed, 1 insertions, 4 deletions
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 83362a155791..75c16215d065 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -2028,7 +2028,6 @@ static int ftrace_hash_ipmodify_update(struct ftrace_ops *ops, static void print_ip_ins(const char *fmt, const unsigned char *p) { char ins[MCOUNT_INSN_SIZE]; - int i; if (copy_from_kernel_nofault(ins, p, MCOUNT_INSN_SIZE)) { printk(KERN_CONT "%s[FAULT] %px\n", fmt, p); @@ -2036,9 +2035,7 @@ static void print_ip_ins(const char *fmt, const unsigned char *p) } printk(KERN_CONT "%s", fmt); - - for (i = 0; i < MCOUNT_INSN_SIZE; i++) - printk(KERN_CONT "%s%02x", i ? ":" : "", ins[i]); + pr_cont("%*phC", MCOUNT_INSN_SIZE, ins); } enum ftrace_bug_type ftrace_bug_type; |