* [tip:objtool/core 8/12] vmlinux.o: warning: objtool: rust_begin_unwind+0x5c: rust_helper_BUG() is missing a __noreturn annotation
@ 2023-06-06 20:57 kernel test robot
2023-06-06 21:52 ` Josh Poimboeuf
0 siblings, 1 reply; 5+ messages in thread
From: kernel test robot @ 2023-06-06 20:57 UTC (permalink / raw)
To: Josh Poimboeuf; +Cc: llvm, oe-kbuild-all, linux-kernel, x86, Miroslav Benes
tree: https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git objtool/core
head: ff9a6459bbec06df7da2545020d7383aba13b3fb
commit: fedb724c3db5490234ddde0103811c28c2fedae0 [8/12] objtool: Detect missing __noreturn annotations
config: x86_64-randconfig-a012-20230606 (https://download.01.org/0day-ci/archive/20230607/202306070408.EFxuDoRs-lkp@intel.com/config)
compiler: clang version 15.0.7 (https://github.com/llvm/llvm-project.git 8dfdcc7b7bf66834a761bd8de445840ef68e4d1a)
reproduce (this is a W=1 build):
mkdir -p ~/bin
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git/commit/?id=fedb724c3db5490234ddde0103811c28c2fedae0
git remote add tip https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git
git fetch --no-tags tip objtool/core
git checkout fedb724c3db5490234ddde0103811c28c2fedae0
# save the config file
mkdir build_dir && cp config build_dir/.config
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang ~/bin/make.cross W=1 O=build_dir ARCH=x86_64 olddefconfig
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang ~/bin/make.cross W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash
If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202306070408.EFxuDoRs-lkp@intel.com/
All warnings (new ones prefixed by >>):
>> vmlinux.o: warning: objtool: rust_begin_unwind+0x5c: rust_helper_BUG() is missing a __noreturn annotation
objdump-func vmlinux.o rust_begin_unwind:
0000 00000000000b9e69 <rust_begin_unwind>:
0000 b9e69: 48 83 ec 48 sub $0x48,%rsp
0004 b9e6d: 48 89 e0 mov %rsp,%rax
0007 b9e70: 48 89 38 mov %rdi,(%rax)
000a b9e73: 48 8d 4c 24 08 lea 0x8(%rsp),%rcx
000f b9e78: 48 89 01 mov %rax,(%rcx)
0012 b9e7b: 48 c7 41 08 00 00 00 00 movq $0x0,0x8(%rcx) b9e7f: R_X86_64_32S _RNvXsR_NtCs3yuwAp0waWO_4core3fmtRNtNtNtB7_5panic10panic_info9PanicInfoNtB5_7Display3fmtCsfATHBUcknU9_6kernel
001a b9e83: 48 8d 54 24 18 lea 0x18(%rsp),%rdx
001f b9e88: 48 c7 02 00 00 00 00 movq $0x0,(%rdx) b9e8b: R_X86_64_32S .rodata+0x137d8
0026 b9e8f: 48 c7 42 08 02 00 00 00 movq $0x2,0x8(%rdx)
002e b9e97: 48 c7 42 10 00 00 00 00 movq $0x0,0x10(%rdx)
0036 b9e9f: 48 89 4a 20 mov %rcx,0x20(%rdx)
003a b9ea3: 48 c7 42 28 01 00 00 00 movq $0x1,0x28(%rdx)
0042 b9eab: 48 c7 c7 00 00 00 00 mov $0x0,%rdi b9eae: R_X86_64_32S _RNvNtNtCsfATHBUcknU9_6kernel5print14format_strings5EMERG
0049 b9eb2: 48 c7 c6 00 00 00 00 mov $0x0,%rsi b9eb5: R_X86_64_32S .rodata+0x13568
0050 b9eb9: 31 c0 xor %eax,%eax
0052 b9ebb: e8 00 00 00 00 call b9ec0 <rust_begin_unwind+0x57> b9ebc: R_X86_64_PLT32 _printk-0x4
0057 b9ec0: e8 00 00 00 00 call b9ec5 <rust_begin_unwind+0x5c> b9ec1: R_X86_64_PLT32 rust_helper_BUG-0x4
005c b9ec5: eb fe jmp b9ec5 <rust_begin_unwind+0x5c>
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [tip:objtool/core 8/12] vmlinux.o: warning: objtool: rust_begin_unwind+0x5c: rust_helper_BUG() is missing a __noreturn annotation 2023-06-06 20:57 [tip:objtool/core 8/12] vmlinux.o: warning: objtool: rust_begin_unwind+0x5c: rust_helper_BUG() is missing a __noreturn annotation kernel test robot @ 2023-06-06 21:52 ` Josh Poimboeuf 2023-06-06 21:56 ` Alex Gaynor 2023-06-06 22:22 ` Miguel Ojeda 0 siblings, 2 replies; 5+ messages in thread From: Josh Poimboeuf @ 2023-06-06 21:52 UTC (permalink / raw) To: Miguel Ojeda, Wedson Almeida Filho Cc: llvm, oe-kbuild-all, linux-kernel, x86, Miroslav Benes, kernel test robot, Peter Zijlstra, Alex Gaynor, rust-for-linux Hi Miguel, Wedson, Objtool detected that rust_helper_BUG() doesn't return, and seems to be missing a __noreturn. But it actually *does* have __noreturn. The problem is actually that its rust callees don't seem to know that, i.e. they assume it returns. After a little digging I found this comment in rust panic(): unsafe { bindings::BUG() }; // Bindgen currently does not recognize `__noreturn` so `BUG` returns `()` // instead of `!`. See <https://github.com/rust-lang/rust-bindgen/issues/2094>. loop {} So it seems to be an issue with bindgen, though that github issue has been resolved. Any idea when this will show up in a toolchain? In the meantime we may have to get objtool to manually silence the warning, unless you have any better ideas. On Wed, Jun 07, 2023 at 04:57:42AM +0800, kernel test robot wrote: > tree: https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git objtool/core > head: ff9a6459bbec06df7da2545020d7383aba13b3fb > commit: fedb724c3db5490234ddde0103811c28c2fedae0 [8/12] objtool: Detect missing __noreturn annotations > config: x86_64-randconfig-a012-20230606 (https://download.01.org/0day-ci/archive/20230607/202306070408.EFxuDoRs-lkp@intel.com/config) > compiler: clang version 15.0.7 (https://github.com/llvm/llvm-project.git 8dfdcc7b7bf66834a761bd8de445840ef68e4d1a) > reproduce (this is a W=1 build): > mkdir -p ~/bin > wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross > chmod +x ~/bin/make.cross > # https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git/commit/?id=fedb724c3db5490234ddde0103811c28c2fedae0 > git remote add tip https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git > git fetch --no-tags tip objtool/core > git checkout fedb724c3db5490234ddde0103811c28c2fedae0 > # save the config file > mkdir build_dir && cp config build_dir/.config > COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang ~/bin/make.cross W=1 O=build_dir ARCH=x86_64 olddefconfig > COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang ~/bin/make.cross W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash > > If you fix the issue, kindly add following tag where applicable > | Reported-by: kernel test robot <lkp@intel.com> > | Closes: https://lore.kernel.org/oe-kbuild-all/202306070408.EFxuDoRs-lkp@intel.com/ > > All warnings (new ones prefixed by >>): > > >> vmlinux.o: warning: objtool: rust_begin_unwind+0x5c: rust_helper_BUG() is missing a __noreturn annotation > > > objdump-func vmlinux.o rust_begin_unwind: > 0000 00000000000b9e69 <rust_begin_unwind>: > 0000 b9e69: 48 83 ec 48 sub $0x48,%rsp > 0004 b9e6d: 48 89 e0 mov %rsp,%rax > 0007 b9e70: 48 89 38 mov %rdi,(%rax) > 000a b9e73: 48 8d 4c 24 08 lea 0x8(%rsp),%rcx > 000f b9e78: 48 89 01 mov %rax,(%rcx) > 0012 b9e7b: 48 c7 41 08 00 00 00 00 movq $0x0,0x8(%rcx) b9e7f: R_X86_64_32S _RNvXsR_NtCs3yuwAp0waWO_4core3fmtRNtNtNtB7_5panic10panic_info9PanicInfoNtB5_7Display3fmtCsfATHBUcknU9_6kernel > 001a b9e83: 48 8d 54 24 18 lea 0x18(%rsp),%rdx > 001f b9e88: 48 c7 02 00 00 00 00 movq $0x0,(%rdx) b9e8b: R_X86_64_32S .rodata+0x137d8 > 0026 b9e8f: 48 c7 42 08 02 00 00 00 movq $0x2,0x8(%rdx) > 002e b9e97: 48 c7 42 10 00 00 00 00 movq $0x0,0x10(%rdx) > 0036 b9e9f: 48 89 4a 20 mov %rcx,0x20(%rdx) > 003a b9ea3: 48 c7 42 28 01 00 00 00 movq $0x1,0x28(%rdx) > 0042 b9eab: 48 c7 c7 00 00 00 00 mov $0x0,%rdi b9eae: R_X86_64_32S _RNvNtNtCsfATHBUcknU9_6kernel5print14format_strings5EMERG > 0049 b9eb2: 48 c7 c6 00 00 00 00 mov $0x0,%rsi b9eb5: R_X86_64_32S .rodata+0x13568 > 0050 b9eb9: 31 c0 xor %eax,%eax > 0052 b9ebb: e8 00 00 00 00 call b9ec0 <rust_begin_unwind+0x57> b9ebc: R_X86_64_PLT32 _printk-0x4 > 0057 b9ec0: e8 00 00 00 00 call b9ec5 <rust_begin_unwind+0x5c> b9ec1: R_X86_64_PLT32 rust_helper_BUG-0x4 > 005c b9ec5: eb fe jmp b9ec5 <rust_begin_unwind+0x5c> > > -- > 0-DAY CI Kernel Test Service > https://github.com/intel/lkp-tests/wiki -- Josh ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [tip:objtool/core 8/12] vmlinux.o: warning: objtool: rust_begin_unwind+0x5c: rust_helper_BUG() is missing a __noreturn annotation 2023-06-06 21:52 ` Josh Poimboeuf @ 2023-06-06 21:56 ` Alex Gaynor 2023-06-06 22:22 ` Miguel Ojeda 1 sibling, 0 replies; 5+ messages in thread From: Alex Gaynor @ 2023-06-06 21:56 UTC (permalink / raw) To: Josh Poimboeuf Cc: Miguel Ojeda, Wedson Almeida Filho, llvm, oe-kbuild-all, linux-kernel, x86, Miroslav Benes, kernel test robot, Peter Zijlstra, rust-for-linux The fix to properly handle noreturn is present in bindgen > 0.61.0. Per min-tool-version.sh, we currently only require bindgen 0.56.0 or newer. I'm not sure if there are obstacles to requiring a newer bindgen version, at which point the loop {} would not be required. Cheers, Alex On Tue, Jun 6, 2023 at 5:52 PM Josh Poimboeuf <jpoimboe@kernel.org> wrote: > > Hi Miguel, Wedson, > > Objtool detected that rust_helper_BUG() doesn't return, and seems to be > missing a __noreturn. But it actually *does* have __noreturn. The > problem is actually that its rust callees don't seem to know that, i.e. > they assume it returns. > > After a little digging I found this comment in rust panic(): > > unsafe { bindings::BUG() }; > // Bindgen currently does not recognize `__noreturn` so `BUG` returns `()` > // instead of `!`. See <https://github.com/rust-lang/rust-bindgen/issues/2094>. > loop {} > > So it seems to be an issue with bindgen, though that github issue has > been resolved. Any idea when this will show up in a toolchain? > > In the meantime we may have to get objtool to manually silence the > warning, unless you have any better ideas. > > On Wed, Jun 07, 2023 at 04:57:42AM +0800, kernel test robot wrote: > > tree: https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git objtool/core > > head: ff9a6459bbec06df7da2545020d7383aba13b3fb > > commit: fedb724c3db5490234ddde0103811c28c2fedae0 [8/12] objtool: Detect missing __noreturn annotations > > config: x86_64-randconfig-a012-20230606 (https://download.01.org/0day-ci/archive/20230607/202306070408.EFxuDoRs-lkp@intel.com/config) > > compiler: clang version 15.0.7 (https://github.com/llvm/llvm-project.git 8dfdcc7b7bf66834a761bd8de445840ef68e4d1a) > > reproduce (this is a W=1 build): > > mkdir -p ~/bin > > wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross > > chmod +x ~/bin/make.cross > > # https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git/commit/?id=fedb724c3db5490234ddde0103811c28c2fedae0 > > git remote add tip https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git > > git fetch --no-tags tip objtool/core > > git checkout fedb724c3db5490234ddde0103811c28c2fedae0 > > # save the config file > > mkdir build_dir && cp config build_dir/.config > > COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang ~/bin/make.cross W=1 O=build_dir ARCH=x86_64 olddefconfig > > COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang ~/bin/make.cross W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash > > > > If you fix the issue, kindly add following tag where applicable > > | Reported-by: kernel test robot <lkp@intel.com> > > | Closes: https://lore.kernel.org/oe-kbuild-all/202306070408.EFxuDoRs-lkp@intel.com/ > > > > All warnings (new ones prefixed by >>): > > > > >> vmlinux.o: warning: objtool: rust_begin_unwind+0x5c: rust_helper_BUG() is missing a __noreturn annotation > > > > > > objdump-func vmlinux.o rust_begin_unwind: > > 0000 00000000000b9e69 <rust_begin_unwind>: > > 0000 b9e69: 48 83 ec 48 sub $0x48,%rsp > > 0004 b9e6d: 48 89 e0 mov %rsp,%rax > > 0007 b9e70: 48 89 38 mov %rdi,(%rax) > > 000a b9e73: 48 8d 4c 24 08 lea 0x8(%rsp),%rcx > > 000f b9e78: 48 89 01 mov %rax,(%rcx) > > 0012 b9e7b: 48 c7 41 08 00 00 00 00 movq $0x0,0x8(%rcx) b9e7f: R_X86_64_32S _RNvXsR_NtCs3yuwAp0waWO_4core3fmtRNtNtNtB7_5panic10panic_info9PanicInfoNtB5_7Display3fmtCsfATHBUcknU9_6kernel > > 001a b9e83: 48 8d 54 24 18 lea 0x18(%rsp),%rdx > > 001f b9e88: 48 c7 02 00 00 00 00 movq $0x0,(%rdx) b9e8b: R_X86_64_32S .rodata+0x137d8 > > 0026 b9e8f: 48 c7 42 08 02 00 00 00 movq $0x2,0x8(%rdx) > > 002e b9e97: 48 c7 42 10 00 00 00 00 movq $0x0,0x10(%rdx) > > 0036 b9e9f: 48 89 4a 20 mov %rcx,0x20(%rdx) > > 003a b9ea3: 48 c7 42 28 01 00 00 00 movq $0x1,0x28(%rdx) > > 0042 b9eab: 48 c7 c7 00 00 00 00 mov $0x0,%rdi b9eae: R_X86_64_32S _RNvNtNtCsfATHBUcknU9_6kernel5print14format_strings5EMERG > > 0049 b9eb2: 48 c7 c6 00 00 00 00 mov $0x0,%rsi b9eb5: R_X86_64_32S .rodata+0x13568 > > 0050 b9eb9: 31 c0 xor %eax,%eax > > 0052 b9ebb: e8 00 00 00 00 call b9ec0 <rust_begin_unwind+0x57> b9ebc: R_X86_64_PLT32 _printk-0x4 > > 0057 b9ec0: e8 00 00 00 00 call b9ec5 <rust_begin_unwind+0x5c> b9ec1: R_X86_64_PLT32 rust_helper_BUG-0x4 > > 005c b9ec5: eb fe jmp b9ec5 <rust_begin_unwind+0x5c> > > > > -- > > 0-DAY CI Kernel Test Service > > https://github.com/intel/lkp-tests/wiki > > -- > Josh -- All that is necessary for evil to succeed is for good people to do nothing. ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [tip:objtool/core 8/12] vmlinux.o: warning: objtool: rust_begin_unwind+0x5c: rust_helper_BUG() is missing a __noreturn annotation 2023-06-06 21:52 ` Josh Poimboeuf 2023-06-06 21:56 ` Alex Gaynor @ 2023-06-06 22:22 ` Miguel Ojeda 2023-06-06 22:29 ` Josh Poimboeuf 1 sibling, 1 reply; 5+ messages in thread From: Miguel Ojeda @ 2023-06-06 22:22 UTC (permalink / raw) To: Josh Poimboeuf Cc: Miguel Ojeda, Wedson Almeida Filho, llvm, oe-kbuild-all, linux-kernel, x86, Miroslav Benes, kernel test robot, Peter Zijlstra, Alex Gaynor, rust-for-linux On Tue, Jun 6, 2023 at 11:52 PM Josh Poimboeuf <jpoimboe@kernel.org> wrote: > > So it seems to be an issue with bindgen, though that github issue has > been resolved. Any idea when this will show up in a toolchain? > > In the meantime we may have to get objtool to manually silence the > warning, unless you have any better ideas. We were going to update `bindgen`, so we can just do that -- one more reason to do so! :) If the update goes into the upcoming merge window, would that be fine with you? Or do you need it for this current cycle? Thanks! Cheers, Miguel ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [tip:objtool/core 8/12] vmlinux.o: warning: objtool: rust_begin_unwind+0x5c: rust_helper_BUG() is missing a __noreturn annotation 2023-06-06 22:22 ` Miguel Ojeda @ 2023-06-06 22:29 ` Josh Poimboeuf 0 siblings, 0 replies; 5+ messages in thread From: Josh Poimboeuf @ 2023-06-06 22:29 UTC (permalink / raw) To: Miguel Ojeda Cc: Miguel Ojeda, Wedson Almeida Filho, llvm, oe-kbuild-all, linux-kernel, x86, Miroslav Benes, kernel test robot, Peter Zijlstra, Alex Gaynor, rust-for-linux On Wed, Jun 07, 2023 at 12:22:45AM +0200, Miguel Ojeda wrote: > On Tue, Jun 6, 2023 at 11:52 PM Josh Poimboeuf <jpoimboe@kernel.org> wrote: > > > > So it seems to be an issue with bindgen, though that github issue has > > been resolved. Any idea when this will show up in a toolchain? > > > > In the meantime we may have to get objtool to manually silence the > > warning, unless you have any better ideas. > > We were going to update `bindgen`, so we can just do that -- one more > reason to do so! :) > > If the update goes into the upcoming merge window, would that be fine > with you? Or do you need it for this current cycle? The next merge window would be good. Eventually I want to get objtool to zero warnings so we can do -Werror, but we're not there yet :-) Thanks! -- Josh ^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2023-06-06 22:29 UTC | newest] Thread overview: 5+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2023-06-06 20:57 [tip:objtool/core 8/12] vmlinux.o: warning: objtool: rust_begin_unwind+0x5c: rust_helper_BUG() is missing a __noreturn annotation kernel test robot 2023-06-06 21:52 ` Josh Poimboeuf 2023-06-06 21:56 ` Alex Gaynor 2023-06-06 22:22 ` Miguel Ojeda 2023-06-06 22:29 ` Josh Poimboeuf
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