Hi Christophe,

On 24/05/22 18:47, Christophe Leroy wrote:

This draft series adds PPC32 support to Sathvika's series.
Verified on pmac32 on QEMU.

It should in principle also work for PPC64 BE but for the time being
something goes wrong. In the beginning I had a segfaut hence the first
patch. But I still get no mcount section in the files.

Since PPC64 BE uses older elfv1 ABI, it prepends a dot to symbols.
And so, the relocation records in case of PPC64BE point to "._mcount",
rather than just "_mcount". We should be looking for "._mcount" to be
able to generate mcount_loc section in the files.

Like:

diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 70be5a72e838..7da5bf8c7236 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c

@@ -2185,7 +2185,7 @@ static int classify_symbols(struct objtool_file *file)
                         if (arch_is_retpoline(func))
                                 func->retpoline_thunk = true;

-                       if ((!strcmp(func->name, "__fentry__")) || 

(!strcmp(func->name, "_mcount")))
+                       if ((!strcmp(func->name, "__fentry__")) || 
(!strcmp(func->name, "_mcount")) || (!strcmp(func->name, "._mcount")))
                                 func->fentry = true;

                         if (is_profiling_func(func->name))


With this change, I could see __mcount_loc section being
generated in individual ppc64be object files.

- Sathvika