* vmlinux.o: warning: objtool: __svm_sev_es_vcpu_run()+0x54: BP used as a scratch register
@ 2021-11-17 12:41 ` kernel test robot
0 siblings, 0 replies; 4+ messages in thread
From: kernel test robot @ 2021-11-17 12:41 UTC (permalink / raw)
To: Tom Lendacky; +Cc: kbuild-all, linux-kernel, Paolo Bonzini
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tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head: 8ab774587903771821b59471cc723bba6d893942
commit: 16809ecdc1e8ab7278f1d60021ac809edd17d060 KVM: SVM: Provide an updated VMRUN invocation for SEV-ES guests
date: 11 months ago
config: x86_64-buildonly-randconfig-r005-20211117 (attached as .config)
compiler: gcc-9 (Debian 9.3.0-22) 9.3.0
reproduce (this is a W=1 build):
# https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=16809ecdc1e8ab7278f1d60021ac809edd17d060
git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
git fetch --no-tags linus master
git checkout 16809ecdc1e8ab7278f1d60021ac809edd17d060
# save the attached .config to linux build tree
mkdir build_dir
make W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>
All warnings (new ones prefixed by >>):
vmlinux.o: warning: objtool: __do_fast_syscall_32()+0x3d: call to syscall_enter_from_user_mode_work() leaves .noinstr.text section
vmlinux.o: warning: objtool: __svm_vcpu_run()+0x10e: BP used as a scratch register
>> vmlinux.o: warning: objtool: __svm_sev_es_vcpu_run()+0x54: BP used as a scratch register
vmlinux.o: warning: objtool: do_machine_check()+0x93c: call to mce_panic.isra.0() leaves .noinstr.text section
vmlinux.o: warning: objtool: match_held_lock()+0xcd: call to rcu_read_lock_any_held() leaves .noinstr.text section
vmlinux.o: warning: objtool: lock_is_held_type()+0x67: call to check_flags.part.0() leaves .noinstr.text section
---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
[-- Attachment #2: .config.gz --]
[-- Type: application/gzip, Size: 28068 bytes --]
^ permalink raw reply [flat|nested] 4+ messages in thread* vmlinux.o: warning: objtool: __svm_sev_es_vcpu_run()+0x54: BP used as a scratch register
@ 2021-11-17 12:41 ` kernel test robot
0 siblings, 0 replies; 4+ messages in thread
From: kernel test robot @ 2021-11-17 12:41 UTC (permalink / raw)
To: kbuild-all
[-- Attachment #1: Type: text/plain, Size: 1834 bytes --]
tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head: 8ab774587903771821b59471cc723bba6d893942
commit: 16809ecdc1e8ab7278f1d60021ac809edd17d060 KVM: SVM: Provide an updated VMRUN invocation for SEV-ES guests
date: 11 months ago
config: x86_64-buildonly-randconfig-r005-20211117 (attached as .config)
compiler: gcc-9 (Debian 9.3.0-22) 9.3.0
reproduce (this is a W=1 build):
# https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=16809ecdc1e8ab7278f1d60021ac809edd17d060
git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
git fetch --no-tags linus master
git checkout 16809ecdc1e8ab7278f1d60021ac809edd17d060
# save the attached .config to linux build tree
mkdir build_dir
make W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>
All warnings (new ones prefixed by >>):
vmlinux.o: warning: objtool: __do_fast_syscall_32()+0x3d: call to syscall_enter_from_user_mode_work() leaves .noinstr.text section
vmlinux.o: warning: objtool: __svm_vcpu_run()+0x10e: BP used as a scratch register
>> vmlinux.o: warning: objtool: __svm_sev_es_vcpu_run()+0x54: BP used as a scratch register
vmlinux.o: warning: objtool: do_machine_check()+0x93c: call to mce_panic.isra.0() leaves .noinstr.text section
vmlinux.o: warning: objtool: match_held_lock()+0xcd: call to rcu_read_lock_any_held() leaves .noinstr.text section
vmlinux.o: warning: objtool: lock_is_held_type()+0x67: call to check_flags.part.0() leaves .noinstr.text section
---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all(a)lists.01.org
[-- Attachment #2: config.gz --]
[-- Type: application/gzip, Size: 28068 bytes --]
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: vmlinux.o: warning: objtool: __svm_sev_es_vcpu_run()+0x54: BP used as a scratch register
2021-11-17 12:41 ` kernel test robot
@ 2021-12-30 1:18 ` Sean Christopherson
-1 siblings, 0 replies; 4+ messages in thread
From: Sean Christopherson @ 2021-12-30 1:18 UTC (permalink / raw)
To: kernel test robot; +Cc: Tom Lendacky, kbuild-all, linux-kernel, Paolo Bonzini
On Wed, Nov 17, 2021, kernel test robot wrote:
> tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
> head: 8ab774587903771821b59471cc723bba6d893942
> commit: 16809ecdc1e8ab7278f1d60021ac809edd17d060 KVM: SVM: Provide an updated VMRUN invocation for SEV-ES guests
> date: 11 months ago
> config: x86_64-buildonly-randconfig-r005-20211117 (attached as .config)
> compiler: gcc-9 (Debian 9.3.0-22) 9.3.0
> reproduce (this is a W=1 build):
> # https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=16809ecdc1e8ab7278f1d60021ac809edd17d060
> git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
> git fetch --no-tags linus master
> git checkout 16809ecdc1e8ab7278f1d60021ac809edd17d060
> # save the attached .config to linux build tree
> mkdir build_dir
> make W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash
>
> If you fix the issue, kindly add following tag as appropriate
> Reported-by: kernel test robot <lkp@intel.com>
>
> All warnings (new ones prefixed by >>):
>
> vmlinux.o: warning: objtool: __do_fast_syscall_32()+0x3d: call to syscall_enter_from_user_mode_work() leaves .noinstr.text section
> vmlinux.o: warning: objtool: __svm_vcpu_run()+0x10e: BP used as a scratch register
> >> vmlinux.o: warning: objtool: __svm_sev_es_vcpu_run()+0x54: BP used as a scratch register
__svm_vcpu_run() and __svm_sev_es_vcpu_run() PUSH/POP RBP but don't create a stack
frame, which triggers the objtool warning because objtool things the code is using
BP as a scratch register (obviously). This shows up when CONFIG_FRAME_POINTER=y
and KVM AMD is built into the kernel (apparently 'objtool check' isn't run on modules?).
The easy fix to is add "mov %rsp, %rbp" to create a stack frame. Kinda pointless
since neither function makes true calls to other functions, but the extra MOV is
harmless and it'd be nice to get rid of the objtool warning.
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: vmlinux.o: warning: objtool: __svm_sev_es_vcpu_run()+0x54: BP used as a scratch register
@ 2021-12-30 1:18 ` Sean Christopherson
0 siblings, 0 replies; 4+ messages in thread
From: Sean Christopherson @ 2021-12-30 1:18 UTC (permalink / raw)
To: kbuild-all
[-- Attachment #1: Type: text/plain, Size: 2026 bytes --]
On Wed, Nov 17, 2021, kernel test robot wrote:
> tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
> head: 8ab774587903771821b59471cc723bba6d893942
> commit: 16809ecdc1e8ab7278f1d60021ac809edd17d060 KVM: SVM: Provide an updated VMRUN invocation for SEV-ES guests
> date: 11 months ago
> config: x86_64-buildonly-randconfig-r005-20211117 (attached as .config)
> compiler: gcc-9 (Debian 9.3.0-22) 9.3.0
> reproduce (this is a W=1 build):
> # https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=16809ecdc1e8ab7278f1d60021ac809edd17d060
> git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
> git fetch --no-tags linus master
> git checkout 16809ecdc1e8ab7278f1d60021ac809edd17d060
> # save the attached .config to linux build tree
> mkdir build_dir
> make W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash
>
> If you fix the issue, kindly add following tag as appropriate
> Reported-by: kernel test robot <lkp@intel.com>
>
> All warnings (new ones prefixed by >>):
>
> vmlinux.o: warning: objtool: __do_fast_syscall_32()+0x3d: call to syscall_enter_from_user_mode_work() leaves .noinstr.text section
> vmlinux.o: warning: objtool: __svm_vcpu_run()+0x10e: BP used as a scratch register
> >> vmlinux.o: warning: objtool: __svm_sev_es_vcpu_run()+0x54: BP used as a scratch register
__svm_vcpu_run() and __svm_sev_es_vcpu_run() PUSH/POP RBP but don't create a stack
frame, which triggers the objtool warning because objtool things the code is using
BP as a scratch register (obviously). This shows up when CONFIG_FRAME_POINTER=y
and KVM AMD is built into the kernel (apparently 'objtool check' isn't run on modules?).
The easy fix to is add "mov %rsp, %rbp" to create a stack frame. Kinda pointless
since neither function makes true calls to other functions, but the extra MOV is
harmless and it'd be nice to get rid of the objtool warning.
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2021-12-30 1:18 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
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2021-11-17 12:41 vmlinux.o: warning: objtool: __svm_sev_es_vcpu_run()+0x54: BP used as a scratch register kernel test robot
2021-11-17 12:41 ` kernel test robot
2021-12-30 1:18 ` Sean Christopherson
2021-12-30 1:18 ` Sean Christopherson
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