Le 22/09/2023 à 00:52, Song Liu a écrit :

On Mon, Sep 18, 2023 at 12:31 AM Mike Rapoport [off-list ref] wrote:

quoted

[...]

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diff --git a/include/linux/execmem.h b/include/linux/execmem.h
index 519bdfdca595..09d45ac786e9 100644
--- a/include/linux/execmem.h
+++ b/include/linux/execmem.h

@@ -29,6 +29,7 @@
   * @EXECMEM_KPROBES: parameters for kprobes
   * @EXECMEM_FTRACE: parameters for ftrace
   * @EXECMEM_BPF: parameters for BPF
+ * @EXECMEM_MODULE_DATA: parameters for module data sections
   * @EXECMEM_TYPE_MAX:
   */
  enum execmem_type {

@@ -37,6 +38,7 @@ enum execmem_type {
         EXECMEM_KPROBES,
         EXECMEM_FTRACE,

In longer term, I think we can improve the JITed code and merge
kprobe/ftrace/bpf. to use the same ranges. Also, do we need special
setting for FTRACE? If not, let's just remove it.

How can we do that ? Some platforms like powerpc require executable 
memory for BPF and non-exec mem for KPROBE so it can't be in the same 
area/ranges.

quoted

         EXECMEM_BPF,
+       EXECMEM_MODULE_DATA,
         EXECMEM_TYPE_MAX,
  };

Overall, it is great that kprobe/ftrace/bpf no longer depend on modules.

OTOH, I think we should merge execmem_type and existing mod_mem_type.
Otherwise, we still need to handle page permissions in multiple places.
What is our plan for that?

Christophe