From: Baoquan He <bhe@redhat.com>
To: kexec@lists.infradead.org
Subject: [PATCH] kexec_file: Drop pr_err in weak implementations of arch_kexec_apply_relocations[_add]
Date: Tue, 17 May 2022 17:25:59 +0800 [thread overview]
Message-ID: <YoNqJ/MOSIVwKP/o@MiWiFi-R3L-srv> (raw)
In-Reply-To: <20220425174128.11455-1-naveen.n.rao@linux.vnet.ibm.com>
On 04/25/22 at 11:11pm, Naveen N. Rao wrote:
> kexec_load_purgatory() can fail for many reasons - there is no need to
> print an error when encountering unsupported relocations.
>
> This solves a build issue on powerpc with binutils v2.36 and newer [1].
> Since commit d1bcae833b32f1 ("ELF: Don't generate unused section
> symbols") [2], binutils started dropping section symbols that it thought
I am not familiar with binutils, while wondering if this exists in other
ARCHes except of ppc. Arm64 doesn't have the ARCH override either, do we
have problem with it?
> were unused. This isn't an issue in general, but with kexec_file.c, gcc
> is placing kexec_arch_apply_relocations[_add] into a separate
> .text.unlikely section and the section symbol ".text.unlikely" is being
> dropped. Due to this, recordmcount is unable to find a non-weak symbol
But arch_kexec_apply_relocations_add is weak symbol on ppc.
> in .text.unlikely to generate a relocation record against. Dropping
> pr_err() calls results in these functions being left in .text section,
Why dropping pr_err() can make arch_kexec_apply_relocations_add put in
.text?
> enabling recordmcount to emit a proper relocation record.
>
> [1] https://github.com/linuxppc/issues/issues/388
> [2] https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=d1bcae833b32f1
>
> Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
> ---
> kernel/kexec_file.c | 2 --
> 1 file changed, 2 deletions(-)
>
> diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c
> index 8347fc158d2b96..55d144c58b5278 100644
> --- a/kernel/kexec_file.c
> +++ b/kernel/kexec_file.c
> @@ -121,7 +121,6 @@ int __weak
> arch_kexec_apply_relocations_add(struct purgatory_info *pi, Elf_Shdr *section,
> const Elf_Shdr *relsec, const Elf_Shdr *symtab)
> {
> - pr_err("RELA relocation unsupported.\n");
> return -ENOEXEC;
> }
>
> @@ -138,7 +137,6 @@ int __weak
> arch_kexec_apply_relocations(struct purgatory_info *pi, Elf_Shdr *section,
> const Elf_Shdr *relsec, const Elf_Shdr *symtab)
> {
> - pr_err("REL relocation unsupported.\n");
> return -ENOEXEC;
> }
>
>
> base-commit: 83d8a0d166119de813cad27ae7d61f54f9aea707
> --
> 2.35.1
>
next prev parent reply other threads:[~2022-05-17 9:25 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-04-25 17:41 [PATCH] kexec_file: Drop pr_err in weak implementations of arch_kexec_apply_relocations[_add] Naveen N. Rao
2022-05-17 7:58 ` Naveen N. Rao
2022-05-17 9:25 ` Baoquan He [this message]
2022-05-17 10:19 ` Naveen N. Rao
2022-05-17 15:32 ` Eric W. Biederman
2022-05-18 2:26 ` Michael Ellerman
2022-05-18 7:49 ` Baoquan He
2022-05-18 9:18 ` Naveen N. Rao
2022-05-18 10:11 ` Baoquan He
2022-05-18 14:48 ` Eric W. Biederman
2022-05-18 16:48 ` Naveen N. Rao
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