Le 04/03/2025 à 13:38, Madhavan Srinivasan a écrit :

On 3/4/25 4:58 PM, Madhavan Srinivasan wrote:

quoted

On 3/4/25 2:26 PM, Christophe Leroy wrote:

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Le 04/03/2025 à 07:13, Madhavan Srinivasan a écrit :

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On 3/4/25 10:42 AM, Venkat Rao Bagalkote wrote:

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Greetings!!


Observing build warnings with linux-next and powerpc repo's. Issue is currently not seen on mainline yet.

PPC Repo: https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgit.kernel.org%2Fpub%2Fscm%2Flinux%2Fkernel%2Fgit%2Fpowerpc%2Flinux.git&data=05%7C02%7Cchristophe.leroy%40csgroup.eu%7C48de41657f8341b927e708dd5b198b84%7C8b87af7d86474dc78df45f69a2011bb5%7C0%7C0%7C638766887458137690%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=P9JQJ7joMFHGDws1H0iaxpj6blYAqsh4ATzrmB1A8Yc%3D&reserved=0 merge branch

PPC Kernel Version: 6.14.0-rc4-g1304f486dbf1
next Repo: https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgit.kernel.org%2Fpub%2Fscm%2Flinux%2Fkernel%2Fgit%2Fnext%2Flinux-next.git&data=05%7C02%7Cchristophe.leroy%40csgroup.eu%7C48de41657f8341b927e708dd5b198b84%7C8b87af7d86474dc78df45f69a2011bb5%7C0%7C0%7C638766887458152652%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=ZVQdCx62Z3ekoXOrWoE6SdHv4RvgjDFSE9CHPPJ%2FiyI%3D&reserved=0 master branch

next Kernel Version: 6.14.0-rc5-next-20250303


On linux-next kernel issue got introduced b/w next-20250227 and next-20250303


Build Warnings:

arch/powerpc/kvm/book3s_hv_rmhandlers.o: warning: objtool: .text+0xe84: intra_function_call not a direct call
arch/powerpc/crypto/ghashp8-ppc.o: warning: objtool: .text+0x22c: unannotated intra-function call
arch/powerpc/kernel/switch.o: warning: objtool: .text+0x4: intra_function_call not a direct call

Can you please specific the compiler and compiler version you found this issue with

Can you also tell which defconfig you are using or provide your .config

It might also be helpfull if you can provide a disassembly of the three file.o around the warned address.

I could recreate the issue with gcc 11.4.1 20231218 with today's linux-next (but could not recreate with gcc 14 or gcc 11.3.0)

(20d5c66e1810 (HEAD -> master, tag: next-20250304, origin/master, origin/HEAD) Add linux-next specific files for 20250304)

warning for one of the switch.S file :

   CC      arch/powerpc/kernel/syscalls.o
   AS      arch/powerpc/kernel/switch.o
arch/powerpc/kernel/switch.o: warning: objtool: .text+0x4: intra_function_call not a direct call

I guess this is becos, for bl .+4, we recently added in the arch_decode_instruction (decode.c) to set the type as INSN_OTHER

         case 18: /* b[l][a] */
                 if (ins == 0x48000005)  /* bl .+4 */
                         typ = INSN_OTHER;

Which I think is the issue here, changing it to INSN_CALL from INSN_OTHER fixes the warning

Yes indeed I ended up with the same conclusion. However if you change it 
back to INSN_CALL you just bring back the issue with clang using bl .+4 
for relocatable code.

The warning is from here:

static int __annotate_ifc(struct objtool_file *file, int type, struct 
instruction *insn)
{
	unsigned long dest_off;

	if (type != ANNOTYPE_INTRA_FUNCTION_CALL)
		return 0;

	if (insn->type != INSN_CALL) {
		WARN_INSN(insn, "intra_function_call not a direct call");
		return -1;
	}


Now that arch_decode_instruction() does not consider bl .+4 an INSN_CALL 
anymore, we have to remove the ANNOTATE_INTRA_FUNCTION_CALL annotations 
here:

arch/powerpc/kernel/switch.S:42:        ANNOTATE_INTRA_FUNCTION_CALL
arch/powerpc/kvm/book3s_hv_rmhandlers.S:1527:   ANNOTATE_INTRA_FUNCTION_CALL
arch/powerpc/kvm/book3s_hv_rmhandlers.S:1534:   ANNOTATE_INTRA_FUNCTION_CALL

The one in arch/powerpc/kexec/relocate_32.S is not a problem at the 
moment but it looks buggy and that "bl 1f" should be replaced by a 
branch to the "bcl 20,31,$+4"

I will try to cook a couple patches for all that.

The last one from the report is:

arch/powerpc/crypto/ghashp8-ppc.o: warning: objtool: .text+0x22c: 
unannotated intra-function call

That one is different, we need to reproduce it to understand what it is.

Christophe