| Message ID | de2a262e97e7b173548b909a608e9e99aab38e9d.1639509500.git.reinette.chatre@intel.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [V2] selftests/sgx: Fix build error caused by missing dependency | expand |
On 12/14/21 12:26 PM, Reinette Chatre wrote: > Commit f0ff2447b861 ("selftests/sgx: Add a new kselftest: > Unclobbered_vdso_oversubscribed") depends on __cpuid() without > providing the dependency and thus introduces a build error: > > $ make > gcc -Wall -Werror -g -I../../../../tools/include -fPIC -z noexecstack -c main.c -o ../linux/tools/testing/selftests/sgx/main.o > main.c: In function ‘get_total_epc_mem’: > main.c:296:3: error: implicit declaration of function ‘__cpuid’ [-Werror=implicit-function-declaration] > 296 | __cpuid(&eax, &ebx, &ecx, &edx); > | ^~~~~~~ > cc1: all warnings being treated as errors > make: *** [Makefile:33: ../linux/tools/testing/selftests/sgx/main.o] Error 1 > $ > > Clone kernel's __cpuid() implementation to the self-test in order > to make it available to the EPC enumeration code. > > Fixes: f0ff2447b861 ("selftests/sgx: Add a new kselftest: Unclobbered_vdso_oversubscribed") > Reported-by: Jarkko Sakkinen <jarkko@kernel.org> > Signed-off-by: Reinette Chatre <reinette.chatre@intel.com> > --- > > The commit introducing the issue can be found on > the x86/sgx branch of tip.git. > > Changes since V1: > - V1: https://lore.kernel.org/linux-sgx/797ff1331cfe540fc378fcc4a4a7b00ff5099fbe.1638905135.git.reinette.chatre@intel.com/ > - Improve commit message. (Jarkko) > > tools/testing/selftests/sgx/main.c | 12 ++++++++++++ > 1 file changed, 12 insertions(+) > > diff --git a/tools/testing/selftests/sgx/main.c b/tools/testing/selftests/sgx/main.c > index 7e912db4c6c5..6dead57a3121 100644 > --- a/tools/testing/selftests/sgx/main.c > +++ b/tools/testing/selftests/sgx/main.c > @@ -73,6 +73,18 @@ static bool vdso_get_symtab(void *addr, struct vdso_symtab *symtab) > return true; > } > > +static inline void __cpuid(unsigned int *eax, unsigned int *ebx, > + unsigned int *ecx, unsigned int *edx) > +{ > + asm volatile("cpuid" > + : "=a" (*eax), > + "=b" (*ebx), > + "=c" (*ecx), > + "=d" (*edx) > + : "0" (*eax), "2" (*ecx) > + : "memory"); > +} > + > static unsigned long elf_sym_hash(const char *name) > { > unsigned long h = 0, high; > Let's not add one more __cpuid() define to the individual tests. We so far have: tools/testing/selftests/vm/pkey-x86.h selftests/x86/corrupt_xstate_header.c Let's move the defines to kselftest.h and remove all these duplicate defines. For now you could include vm/pkey-x86.h just to fix the build error and do the proper cleanup. There has been a proliferation of defines in tools and selftests. I just fixed/remove 25+ ARRAY_SIZE duplicate define in selftests. thanks, -- Shuah
Hi Shuah, On 12/14/2021 12:10 PM, Shuah Khan wrote: > > Let's not add one more __cpuid() define to the individual tests. > We so far have: > > tools/testing/selftests/vm/pkey-x86.h > selftests/x86/corrupt_xstate_header.c > > Let's move the defines to kselftest.h and remove all these duplicate > defines. > > For now you could include vm/pkey-x86.h just to fix the build error > and do the proper cleanup. Thank you so much for taking a look. We actually do have an alternative fix that could be considered for the other users of __cpuid(). Instead of another clone of the kernel's __cpuid() the fix includes cpuid.h and uses the existing __cpuid_count() from it. Please see: https://lore.kernel.org/linux-sgx/20211204202355.23005-1-jarkko@kernel.org/ We decided against the above fix using __cpuid_count() because we could not explain why all the existing users of __cpuid() implement their own and decided to follow the custom instead ... Do you see any problem with including cpuid.h into a selftest? If not, then we can go back to our original fix of this issue and I could also submit a change to remove all the __cpuid() clones and replace them with the library's __cpuid_count(). Reinette
On 12/14/21 2:28 PM, Reinette Chatre wrote: > Hi Shuah, > > On 12/14/2021 12:10 PM, Shuah Khan wrote: > >> >> Let's not add one more __cpuid() define to the individual tests. >> We so far have: >> >> tools/testing/selftests/vm/pkey-x86.h >> selftests/x86/corrupt_xstate_header.c >> >> Let's move the defines to kselftest.h and remove all these duplicate >> defines. >> >> For now you could include vm/pkey-x86.h just to fix the build error >> and do the proper cleanup. > > Thank you so much for taking a look. We actually do have an alternative fix that could be considered for the other users of __cpuid(). Instead of another clone of the kernel's __cpuid() the fix includes cpuid.h and uses the existing __cpuid_count() from it. > > Please see: > https://lore.kernel.org/linux-sgx/20211204202355.23005-1-jarkko@kernel.org/ > This looks good to me. > We decided against the above fix using __cpuid_count() because we could not explain why all the existing users of __cpuid() implement their own and decided to follow the custom instead ... > Most likely, copy and paste and taking the easy route. I looked at a couple of defines and I dont't see a difference. If there are differences, that would be a bigger concern. The whole idea of not having duplicates is that we don't have bugs in these duplicates. > Do you see any problem with including cpuid.h into a selftest? If not, then we can go back to our original fix of this issue and I could also submit a change to remove all the __cpuid() clones and replace them with the library's __cpuid_count(). > There are no problems including cpuid.h - where is this though. I couldn't find it in my cscope search? thanks, -- Shuah
Hi Shuah, On 12/14/2021 1:55 PM, Shuah Khan wrote: > On 12/14/21 2:28 PM, Reinette Chatre wrote: >> Hi Shuah, >> >> On 12/14/2021 12:10 PM, Shuah Khan wrote: >> >>> >>> Let's not add one more __cpuid() define to the individual tests. >>> We so far have: >>> >>> tools/testing/selftests/vm/pkey-x86.h >>> selftests/x86/corrupt_xstate_header.c >>> >>> Let's move the defines to kselftest.h and remove all these duplicate >>> defines. >>> >>> For now you could include vm/pkey-x86.h just to fix the build error >>> and do the proper cleanup. >> >> Thank you so much for taking a look. We actually do have an >> alternative fix that could be considered for the other users of >> __cpuid(). Instead of another clone of the kernel's __cpuid() the fix >> includes cpuid.h and uses the existing __cpuid_count() from it. >> >> Please see: >> https://lore.kernel.org/linux-sgx/20211204202355.23005-1-jarkko@kernel.org/ >> >> > > This looks good to me. Thank you very much for taking a look. > >> We decided against the above fix using __cpuid_count() because we >> could not explain why all the existing users of __cpuid() implement >> their own and decided to follow the custom instead ... >> > > Most likely, copy and paste and taking the easy route. I looked at a > couple of > defines and I dont't see a difference. If there are differences, that > would be > a bigger concern. The whole idea of not having duplicates is that we > don't have > bugs in these duplicates. > >> Do you see any problem with including cpuid.h into a selftest? If not, >> then we can go back to our original fix of this issue and I could also >> submit a change to remove all the __cpuid() clones and replace them >> with the library's __cpuid_count(). >> > > There are no problems including cpuid.h - where is this though. I > couldn't find > it in my cscope search? On my system it arrived via user space's libgcc-dev package. This does not seem to be the first time including files from this source - I did a quick check and from what I can tell existing includes like stdarg.h, stdbool.h, stdatomic.h, unwind.h, x86intrin.h ... arrive via libgcc-dev. Do you still find that cpuid.h is ok to include? Reinette
On 12/14/21 3:27 PM, Reinette Chatre wrote: > Hi Shuah, > > On 12/14/2021 1:55 PM, Shuah Khan wrote: >> On 12/14/21 2:28 PM, Reinette Chatre wrote: >>> Hi Shuah, >>> >>> On 12/14/2021 12:10 PM, Shuah Khan wrote: >>> >>>> >>>> Let's not add one more __cpuid() define to the individual tests. >>>> We so far have: >>>> >>>> tools/testing/selftests/vm/pkey-x86.h >>>> selftests/x86/corrupt_xstate_header.c >>>> >>>> Let's move the defines to kselftest.h and remove all these duplicate >>>> defines. >>>> >>>> For now you could include vm/pkey-x86.h just to fix the build error >>>> and do the proper cleanup. >>> >>> Thank you so much for taking a look. We actually do have an alternative fix that could be considered for the other users of __cpuid(). Instead of another clone of the kernel's __cpuid() the fix includes cpuid.h and uses the existing __cpuid_count() from it. >>> >>> Please see: >>> https://lore.kernel.org/linux-sgx/20211204202355.23005-1-jarkko@kernel.org/ >>> >> >> This looks good to me. > > Thank you very much for taking a look. > >> >>> We decided against the above fix using __cpuid_count() because we could not explain why all the existing users of __cpuid() implement their own and decided to follow the custom instead ... >>> >> >> Most likely, copy and paste and taking the easy route. I looked at a couple of >> defines and I dont't see a difference. If there are differences, that would be >> a bigger concern. The whole idea of not having duplicates is that we don't have >> bugs in these duplicates. >> >>> Do you see any problem with including cpuid.h into a selftest? If not, then we can go back to our original fix of this issue and I could also submit a change to remove all the __cpuid() clones and replace them with the library's __cpuid_count(). >>> >> >> There are no problems including cpuid.h - where is this though. I couldn't find >> it in my cscope search? > > On my system it arrived via user space's libgcc-dev package. This does not seem to be the first time including files from this source - I did a quick check and from what I can tell existing includes like stdarg.h, stdbool.h, stdatomic.h, unwind.h, x86intrin.h ... arrive via libgcc-dev. > > Do you still find that cpuid.h is ok to include? > > Reinette Yes. I found it on my system as well. /usr/lib/llvm-13/lib/clang/13.0.0/include/cpuid.h /usr/lib/llvm-12/lib/clang/12.0.1/include/cpuid.h /usr/lib/gcc/x86_64-linux-gnu/11/include/cpuid.h /usr/lib/gcc/x86_64-linux-gnu/10/include/cpuid.h No problems using it. thanks, -- Shuah
diff --git a/tools/testing/selftests/sgx/main.c b/tools/testing/selftests/sgx/main.c index 7e912db4c6c5..6dead57a3121 100644 --- a/tools/testing/selftests/sgx/main.c +++ b/tools/testing/selftests/sgx/main.c @@ -73,6 +73,18 @@ static bool vdso_get_symtab(void *addr, struct vdso_symtab *symtab) return true; } +static inline void __cpuid(unsigned int *eax, unsigned int *ebx, + unsigned int *ecx, unsigned int *edx) +{ + asm volatile("cpuid" + : "=a" (*eax), + "=b" (*ebx), + "=c" (*ecx), + "=d" (*edx) + : "0" (*eax), "2" (*ecx) + : "memory"); +} + static unsigned long elf_sym_hash(const char *name) { unsigned long h = 0, high;
Commit f0ff2447b861 ("selftests/sgx: Add a new kselftest: Unclobbered_vdso_oversubscribed") depends on __cpuid() without providing the dependency and thus introduces a build error: $ make gcc -Wall -Werror -g -I../../../../tools/include -fPIC -z noexecstack -c main.c -o ../linux/tools/testing/selftests/sgx/main.o main.c: In function ‘get_total_epc_mem’: main.c:296:3: error: implicit declaration of function ‘__cpuid’ [-Werror=implicit-function-declaration] 296 | __cpuid(&eax, &ebx, &ecx, &edx); | ^~~~~~~ cc1: all warnings being treated as errors make: *** [Makefile:33: ../linux/tools/testing/selftests/sgx/main.o] Error 1 $ Clone kernel's __cpuid() implementation to the self-test in order to make it available to the EPC enumeration code. Fixes: f0ff2447b861 ("selftests/sgx: Add a new kselftest: Unclobbered_vdso_oversubscribed") Reported-by: Jarkko Sakkinen <jarkko@kernel.org> Signed-off-by: Reinette Chatre <reinette.chatre@intel.com> --- The commit introducing the issue can be found on the x86/sgx branch of tip.git. Changes since V1: - V1: https://lore.kernel.org/linux-sgx/797ff1331cfe540fc378fcc4a4a7b00ff5099fbe.1638905135.git.reinette.chatre@intel.com/ - Improve commit message. (Jarkko) tools/testing/selftests/sgx/main.c | 12 ++++++++++++ 1 file changed, 12 insertions(+)