Merge tag 'trace-v5.0-rc4-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace (10f49021) · Commits · 戴 / test

Pull tracing fixes from Steven Rostedt: "Two more tracing fixes - Have kprobes not use copy_from_user() to access kernel addresses, because kprobes can legitimately poke at bad kernel memory, which will fault. Copy from user code should never fault in kernel space. Using probe_mem_read() can handle kernel address space faulting. - Put back the entries counter in the tracing output that was accidentally removed" * tag 'trace-v5.0-rc4-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: tracing: Fix number of entries in trace header kprobe: Do not use uaccess functions to access kernel memory that can fault

kernel/trace/trace.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -3384,6 +3384,8 @@ static void print_func_help_header_irq(struct trace_buffer *buf, struct seq_file
		const char tgid_space[] = " ";
		const char space[] = " ";

		print_event_info(buf, m);

		seq_printf(m, "# %s _-----=> irqs-off\n",
		tgid ? tgid_space : space);
		seq_printf(m, "# %s / _----=> need-resched\n",

kernel/trace/trace_kprobe.c

+1 −9

Original line number	Diff line number	Diff line
		@@ -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();

		do {
		ret = __copy_from_user_inatomic(&c, (u8 *)addr + len, 1);
		ret = probe_mem_read(&c, (u8 *)addr + len, 1);
		len++;
		} while (c && ret == 0 && len < MAX_STRING_SIZE);

		pagefault_enable();
		set_fs(old_fs);

		return (ret < 0) ? ret : len;
		}

Admin message