Le 24/06/2022 à 20:32, Sathvika Vasireddy a écrit :

objtool is throwing *unannotated intra-function call*
warnings with a few instructions that are marked
unreachable. Remove unreachable() from WARN_ON()
to fix these warnings, as the codegen remains same
with and without unreachable() in WARN_ON().

Did you try the two exemples described in commit 1e688dd2a3d6 
("powerpc/bug: Provide better flexibility to WARN_ON/__WARN_FLAGS() with 
asm goto") ?

Without your patch:

00000640 <test>:
  640:	81 23 00 84 	lwz     r9,132(r3)
  644:	71 29 40 00 	andi.   r9,r9,16384
  648:	40 82 00 0c 	bne     654 <test+0x14>
  64c:	80 63 00 0c 	lwz     r3,12(r3)
  650:	4e 80 00 20 	blr
  654:	0f e0 00 00 	twui    r0,0

00000658 <test9w>:
  658:	2c 04 00 00 	cmpwi   r4,0
  65c:	41 82 00 0c 	beq     668 <test9w+0x10>
  660:	7c 63 23 96 	divwu   r3,r3,r4
  664:	4e 80 00 20 	blr
  668:	0f e0 00 00 	twui    r0,0
  66c:	38 60 00 00 	li      r3,0
  670:	4e 80 00 20 	blr

With your patch:

00000640 <test>:
  640:	81 23 00 84 	lwz     r9,132(r3)
  644:	71 29 40 00 	andi.   r9,r9,16384
  648:	40 82 00 0c 	bne     654 <test+0x14>
  64c:	80 63 00 0c 	lwz     r3,12(r3)
  650:	4e 80 00 20 	blr
  654:	0f e0 00 00 	twui    r0,0
  658:	4b ff ff f4 	b       64c <test+0xc>		<==

0000065c <test9w>:
  65c:	2c 04 00 00 	cmpwi   r4,0
  660:	41 82 00 0c 	beq     66c <test9w+0x10>
  664:	7c 63 23 96 	divwu   r3,r3,r4
  668:	4e 80 00 20 	blr
  66c:	0f e0 00 00 	twui    r0,0
  670:	38 60 00 00 	li      r3,0			<==
  674:	4e 80 00 20 	blr				<==
  678:	38 60 00 00 	li      r3,0
  67c:	4e 80 00 20 	blr