From: Christophe Leroy <christophe.leroy@csgroup.eu>
To: Sathvika Vasireddy <sv@linux.ibm.com>,
"linuxppc-dev@lists.ozlabs.org" <linuxppc-dev@lists.ozlabs.org>
Cc: "peterz@infradead.org" <peterz@infradead.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"rostedt@goodmis.org" <rostedt@goodmis.org>,
"aik@ozlabs.ru" <aik@ozlabs.ru>,
"mingo@redhat.com" <mingo@redhat.com>,
"paulus@samba.org" <paulus@samba.org>,
"jpoimboe@redhat.com" <jpoimboe@redhat.com>,
"naveen.n.rao@linux.vnet.ibm.com"
<naveen.n.rao@linux.vnet.ibm.com>,
"mbenes@suse.cz" <mbenes@suse.cz>
Subject: Re: [RFC PATCH v3 11/12] powerpc: Remove unreachable() from WARN_ON()
Date: Sat, 25 Jun 2022 06:46:54 +0000 [thread overview]
Message-ID: <70b6d08d-aced-7f4e-b958-a3c7ae1a9319@csgroup.eu> (raw)
In-Reply-To: <20220624183238.388144-12-sv@linux.ibm.com>
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
Christophe
>
> Signed-off-by: Sathvika Vasireddy <sv@linux.ibm.com>
> ---
> arch/powerpc/include/asm/bug.h | 1 -
> 1 file changed, 1 deletion(-)
>
> diff --git a/arch/powerpc/include/asm/bug.h b/arch/powerpc/include/asm/bug.h
> index ecbae1832de3..df6c11e008b9 100644
> --- a/arch/powerpc/include/asm/bug.h
> +++ b/arch/powerpc/include/asm/bug.h
> @@ -97,7 +97,6 @@
> __label__ __label_warn_on; \
> \
> WARN_ENTRY("twi 31, 0, 0", BUGFLAG_WARNING | (flags), __label_warn_on); \
> - unreachable(); \
> \
> __label_warn_on: \
> break; \
next prev parent reply other threads:[~2022-06-25 6:48 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-06-24 18:32 [RFC PATCH v3 00/12] objtool: Enable and implement --mcount option on powerpc Sathvika Vasireddy
2022-06-24 18:32 ` [RFC PATCH v3 01/12] objtool: Fix SEGFAULT Sathvika Vasireddy
2022-07-08 15:10 ` Christophe Leroy
2022-06-24 18:32 ` [RFC PATCH v3 02/12] objtool: Use target file endianness instead of a compiled constant Sathvika Vasireddy
2022-06-24 18:32 ` [RFC PATCH v3 03/12] objtool: Use target file class size " Sathvika Vasireddy
2022-07-08 17:35 ` Christophe Leroy
2022-06-24 18:32 ` [RFC PATCH v3 04/12] objtool: Add --mnop as an option to --mcount Sathvika Vasireddy
2022-06-24 18:32 ` [RFC PATCH v3 05/12] powerpc: Skip objtool from running on VDSO files Sathvika Vasireddy
2022-06-24 18:32 ` [RFC PATCH v3 06/12] objtool: Read special sections with alts only when specific options are selected Sathvika Vasireddy
2022-06-24 18:32 ` [RFC PATCH v3 07/12] objtool: Use macros to define arch specific reloc types Sathvika Vasireddy
2022-07-04 11:14 ` Peter Zijlstra
2022-07-04 15:53 ` Christophe Leroy
2022-07-04 16:18 ` Peter Zijlstra
2022-06-24 18:32 ` [RFC PATCH v3 08/12] objtool: Add arch specific function arch_ftrace_match() Sathvika Vasireddy
2022-06-24 18:32 ` [RFC PATCH v3 09/12] objtool/powerpc: Enable objtool to be built on ppc Sathvika Vasireddy
2022-06-24 18:32 ` [RFC PATCH v3 10/12] objtool/powerpc: Add --mcount specific implementation Sathvika Vasireddy
2022-06-24 18:32 ` [RFC PATCH v3 11/12] powerpc: Remove unreachable() from WARN_ON() Sathvika Vasireddy
2022-06-25 6:46 ` Christophe Leroy [this message]
2022-06-27 15:21 ` Sathvika Vasireddy
2022-06-27 15:35 ` Sathvika Vasireddy
2022-06-27 15:46 ` Christophe Leroy
2022-06-29 18:30 ` Christophe Leroy
2022-06-30 8:05 ` Naveen N. Rao
2022-06-30 9:58 ` Christophe Leroy
2022-06-30 10:33 ` Christophe Leroy
2022-06-30 10:37 ` Naveen N. Rao
2022-06-30 15:58 ` Segher Boessenkool
2022-07-04 12:01 ` Peter Zijlstra
2022-07-04 11:43 ` Peter Zijlstra
2022-07-01 2:13 ` Chen Zhongjin
2022-07-01 6:56 ` Sathvika Vasireddy
2022-07-01 11:40 ` [RFC PATCH v3 11/12] powerpc: Remove unreachable() from WARN_ON() (gcc issue ?) Christophe Leroy
2022-07-04 11:45 ` [RFC PATCH v3 11/12] powerpc: Remove unreachable() from WARN_ON() Peter Zijlstra
2022-07-04 12:34 ` Christophe Leroy
2022-07-05 15:48 ` Segher Boessenkool
2022-07-04 12:05 ` Peter Zijlstra
2022-07-04 12:44 ` Christophe Leroy
2022-07-04 14:19 ` Peter Zijlstra
2022-06-24 18:32 ` [RFC PATCH v3 12/12] objtool/powerpc: Fix unannotated intra-function call warnings Sathvika Vasireddy
2022-07-08 15:06 ` [RFC PATCH v3 00/12] objtool: Enable and implement --mcount option on powerpc Christophe Leroy
2022-07-08 15:42 ` Christophe Leroy
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