From: Nathan Chancellor <nathan@kernel.org>
To: Huacai Chen <chenhuacai@kernel.org>,
WANG Xuerui <kernel@xen0n.name>, WANG Rui <wangrui@loongson.cn>
Cc: loongarch@lists.linux.dev, llvm@lists.linux.dev
Subject: objtool warnings "sibling call from callable instruction with modified stack frame" with CONFIG_LTO_CLANG_THIN
Date: Thu, 31 Jul 2025 10:56:55 -0700 [thread overview]
Message-ID: <20250731175655.GA1455142@ax162> (raw)
Hi LoongArch folks,
The kernel test robot recently generated several reports when building
with LLVM that appear to be related (the "warning: objtool:" reports):
https://lore.kernel.org/all/?q=loongarch-randconfig-002-20250730
This can be easily reproduced by enabling CONFIG_LTO_CLANG_THIN on top
of defconfig:
$ make -skj"$(nproc)" ARCH=loongarch LLVM=1 clean defconfig
$ scripts/config -d LTO_NONE -e LTO_CLANG_THIN
$ make -skj"$(nproc)" ARCH=loongarch LLVM=1 olddefconfig all
drivers/char/ipmi/ipmi_devintf.o: warning: objtool: ipmi_ioctl+0x7c: sibling call from callable instruction with modified stack frame
net/802/garp.o: warning: objtool: garp_pdu_rcv+0x170: sibling call from callable instruction with modified stack frame
drivers/rapidio/devices/rio_mport_cdev.o: warning: objtool: mport_cdev_ioctl+0xe4: sibling call from callable instruction with modified stack frame
net/802/mrp.o: warning: objtool: mrp_attr_event+0x5c: sibling call from callable instruction with modified stack frame
net/netfilter/nfnetlink_osf.o: warning: objtool: nf_osf_match_one+0x1ac: unreachable instruction
arch/loongarch/kvm/kvm.o: warning: objtool: kvm_set_memslot+0x22c: sibling call from callable instruction with modified stack frame
arch/loongarch/kvm/kvm.o: warning: objtool: kvm_dev_ioctl+0x68: sibling call from callable instruction with modified stack frame
arch/loongarch/kvm/kvm.o: warning: objtool: kvm_emu_iocsr+0x74: sibling call from callable instruction with modified stack frame
arch/loongarch/kvm/kvm.o: warning: objtool: kvm_emu_mmio_read+0x58: sibling call from callable instruction with modified stack frame
arch/loongarch/kvm/kvm.o: warning: objtool: kvm_emu_mmio_write+0x114: sibling call from callable instruction with modified stack frame
arch/loongarch/kvm/kvm.o: warning: objtool: kvm_handle_gspr.llvm.8483686505109456213+0x230: sibling call from callable instruction with modified stack frame
arch/loongarch/kvm/kvm.o: warning: objtool: kvm_arch_vcpu_ioctl+0x3ac: sibling call from callable instruction with modified stack frame
arch/loongarch/kvm/kvm.o: warning: objtool: kvm_arch_vm_ioctl+0xec: sibling call from callable instruction with modified stack frame
arch/loongarch/kvm/kvm.o: warning: objtool: kvm_ipi_read+0xe8: sibling call from callable instruction with modified stack frame
arch/loongarch/kvm/kvm.o: warning: objtool: kvm_ipi_write+0x12c: sibling call from callable instruction with modified stack frame
arch/loongarch/kvm/kvm.o: warning: objtool: kvm_ipi_regs_access+0x84: sibling call from callable instruction with modified stack frame
arch/loongarch/kvm/kvm.o: warning: objtool: kvm_eiointc_regs_access+0x50: sibling call from callable instruction with modified stack frame
arch/loongarch/kvm/kvm.o: warning: objtool: kvm_pch_pic_regs_access+0x54: sibling call from callable instruction with modified stack frame
arch/loongarch/kvm/kvm.o: warning: objtool: kvm_pch_pic_read+0x64: sibling call from callable instruction with modified stack frame
arch/loongarch/kvm/kvm.o: warning: objtool: kvm_pch_pic_write+0x7c: sibling call from callable instruction with modified stack frame
drivers/char/ipmi/ipmi_si.o: warning: objtool: smi_event_handler+0x120: sibling call from callable instruction with modified stack frame
drivers/char/ipmi/ipmi_si.o: warning: objtool: kcs_event.llvm.13474012466233770392+0x140: sibling call from callable instruction with modified stack frame
...
x86_64 does not see these objtool warnings when LTO is enabled, is this
a backend issue or does objtool need to account for something that LLVM
does yet GCC does not?
Cheers,
Nathan
next reply other threads:[~2025-07-31 17:56 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-07-31 17:56 Nathan Chancellor [this message]
2025-08-05 2:41 ` objtool warnings "sibling call from callable instruction with modified stack frame" with CONFIG_LTO_CLANG_THIN Tiezhu Yang
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20250731175655.GA1455142@ax162 \
--to=nathan@kernel.org \
--cc=chenhuacai@kernel.org \
--cc=kernel@xen0n.name \
--cc=llvm@lists.linux.dev \
--cc=loongarch@lists.linux.dev \
--cc=wangrui@loongson.cn \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox