Hi,
On Thu, 21 Feb 2019 16:52:52 +0900 Masami Hiramatsu mhiramat@kernel.org wrote:
kernel/trace/trace_kprobe.c | 10 +--------- 1 file changed, 1 insertion(+), 9 deletions(-)
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index d5fb09ebba8b..9eaf07f99212 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -861,22 +861,14 @@ static const struct file_operations kprobe_profile_ops = { static nokprobe_inline int fetch_store_strlen(unsigned long addr) {
- mm_segment_t old_fs; int ret, len = 0; u8 c;
- old_fs = get_fs();
- set_fs(KERNEL_DS);
- pagefault_disable();
BTW, compared with probe_kernel_read() implementation, this function lacks current->kernel_uaccess_faults_ok modification here.
I would like to know whether we can avoid this issue if we tweak this flag.
Thank you,
do {
ret = __copy_from_user_inatomic(&c, (u8 *)addr + len, 1);
ret = probe_mem_read(&c, (u8 *)addr + len, 1);
- pagefault_enable();
- set_fs(old_fs);
- return (ret < 0) ? ret : len;
} -- 2.20.1
-- Masami Hiramatsu mhiramat@kernel.org