All of lore.kernel.org
 help / color / mirror / Atom feed
* [tip:x86/vdso 3/4] arch/x86/include/asm/arch_hweight.h:49:15: error: invalid input size for constraint 'D'
@ 2023-02-07  5:39 kernel test robot
  2023-02-07 10:46 ` [PATCH] x86/vdso: Fake 32bit VDSO build on 64bit compile for vgetcpu Sebastian Andrzej Siewior
  0 siblings, 1 reply; 5+ messages in thread
From: kernel test robot @ 2023-02-07  5:39 UTC (permalink / raw)
  To: Sebastian Andrzej Siewior
  Cc: llvm, oe-kbuild-all, linux-kernel, x86, Thomas Gleixner

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git x86/vdso
head:   5646bbd6684acf5c9b9dedb863b7d2f6f5a330fb
commit: 92d33063c081a82d25dd08a9cce03947c8ed9164 [3/4] x86/vdso: Provide getcpu for x86-32.
config: x86_64-randconfig-r031-20230206 (https://download.01.org/0day-ci/archive/20230207/202302071338.m7nBGR5i-lkp@intel.com/config)
compiler: clang version 14.0.6 (https://github.com/llvm/llvm-project f28c006a5895fc0e329fe15fead81e37457cb1d1)
reproduce (this is a W=1 build):
        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=92d33063c081a82d25dd08a9cce03947c8ed9164
        git remote add tip https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git
        git fetch --no-tags tip x86/vdso
        git checkout 92d33063c081a82d25dd08a9cce03947c8ed9164
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=x86_64 olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang 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>

All errors (new ones prefixed by >>):

   In file included from arch/x86/entry/vdso/vdso32/vgetcpu.c:2:
   In file included from arch/x86/entry/vdso/vdso32/../vgetcpu.c:8:
   In file included from include/linux/kernel.h:22:
   In file included from include/linux/bitops.h:68:
   In file included from arch/x86/include/asm/bitops.h:420:
>> arch/x86/include/asm/arch_hweight.h:49:15: error: invalid input size for constraint 'D'
                            : REG_IN (w));
                                      ^
   In file included from arch/x86/entry/vdso/vdso32/vgetcpu.c:2:
   In file included from arch/x86/entry/vdso/vdso32/../vgetcpu.c:8:
   In file included from include/linux/kernel.h:25:
   In file included from include/linux/math.h:6:
>> arch/x86/include/asm/div64.h:85:34: error: invalid output size for constraint '=a'
           asm ("mulq %2; divq %3" : "=a" (q)
                                           ^
   In file included from arch/x86/entry/vdso/vdso32/vgetcpu.c:2:
   arch/x86/entry/vdso/vdso32/../vgetcpu.c:13:1: warning: no previous prototype for function '__vdso_getcpu' [-Wmissing-prototypes]
   __vdso_getcpu(unsigned *cpu, unsigned *node, struct getcpu_cache *unused)
   ^
   arch/x86/entry/vdso/vdso32/../vgetcpu.c:12:9: note: declare 'static' if the function is not intended to be used outside of this translation unit
   notrace long
           ^
           static 
   1 warning and 2 errors generated.


vim +/D +49 arch/x86/include/asm/arch_hweight.h

d61931d89be506 Borislav Petkov 2010-03-05  35  
d14edb1648221e Denys Vlasenko  2015-08-04  36  #ifdef CONFIG_X86_32
d61931d89be506 Borislav Petkov 2010-03-05  37  static inline unsigned long __arch_hweight64(__u64 w)
d61931d89be506 Borislav Petkov 2010-03-05  38  {
d61931d89be506 Borislav Petkov 2010-03-05  39  	return  __arch_hweight32((u32)w) +
d61931d89be506 Borislav Petkov 2010-03-05  40  		__arch_hweight32((u32)(w >> 32));
d14edb1648221e Denys Vlasenko  2015-08-04  41  }
d61931d89be506 Borislav Petkov 2010-03-05  42  #else
d14edb1648221e Denys Vlasenko  2015-08-04  43  static __always_inline unsigned long __arch_hweight64(__u64 w)
d14edb1648221e Denys Vlasenko  2015-08-04  44  {
f5967101e9de12 Borislav Petkov 2016-05-30  45  	unsigned long res;
d14edb1648221e Denys Vlasenko  2015-08-04  46  
566b62a3676cae Uros Bizjak     2018-10-14  47  	asm (ALTERNATIVE("call __sw_hweight64", "popcntq %1, %0", X86_FEATURE_POPCNT)
d61931d89be506 Borislav Petkov 2010-03-05  48  			 : "="REG_OUT (res)
d61931d89be506 Borislav Petkov 2010-03-05 @49  			 : REG_IN (w));
d61931d89be506 Borislav Petkov 2010-03-05  50  
d61931d89be506 Borislav Petkov 2010-03-05  51  	return res;
d61931d89be506 Borislav Petkov 2010-03-05  52  }
d14edb1648221e Denys Vlasenko  2015-08-04  53  #endif /* CONFIG_X86_32 */
d61931d89be506 Borislav Petkov 2010-03-05  54  

:::::: The code at line 49 was first introduced by commit
:::::: d61931d89be506372d01a90d1755f6d0a9fafe2d x86: Add optimized popcnt variants

:::::: TO: Borislav Petkov <borislav.petkov@amd.com>
:::::: CC: H. Peter Anvin <hpa@zytor.com>

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests

^ permalink raw reply	[flat|nested] 5+ messages in thread
* [PATCH] x86/vdso: Fake 32bit VDSO build on 64bit compile for vgetcpu.
  2023-02-07  5:39 [tip:x86/vdso 3/4] arch/x86/include/asm/arch_hweight.h:49:15: error: invalid input size for constraint 'D' kernel test robot
@ 2023-02-07 10:46 ` Sebastian Andrzej Siewior
  2023-02-07 16:45   ` Damian Tometzki
                     ` (2 more replies)
  0 siblings, 3 replies; 5+ messages in thread
From: Sebastian Andrzej Siewior @ 2023-02-07 10:46 UTC (permalink / raw)
  To: kernel test robot, Nathan Chancellor, Nick Desaulniers, Tom Rix
  Cc: llvm, oe-kbuild-all, linux-kernel, x86, Thomas Gleixner,
	Andy Lutomirski, Ingo Molnar, Borislav Petkov, Dave Hansen,
	H. Peter Anvin

The 64bit register constrains in __arch_hweight64() can not be
fulfilled in a 32bit build. The function is only declared, not used
within vclock_gettime.c and gcc does not care. LLVM complains and
aborts.

Move the "fake a 32 bit kernel configuration" bits from vclock_gettime.c
into a common header file. Use this from vclock_gettime.c and vgetcpu.c.

Fixes: 92d33063c081a ("x86/vdso: Provide getcpu for x86-32.")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---
 arch/x86/entry/vdso/vdso32/fake_32bit_build.h | 25 +++++++++++++++++
 arch/x86/entry/vdso/vdso32/vclock_gettime.c   | 27 +------------------
 arch/x86/entry/vdso/vdso32/vgetcpu.c          |  1 +
 3 files changed, 27 insertions(+), 26 deletions(-)
 create mode 100644 arch/x86/entry/vdso/vdso32/fake_32bit_build.h

diff --git a/arch/x86/entry/vdso/vdso32/fake_32bit_build.h b/arch/x86/entry/vdso/vdso32/fake_32bit_build.h
new file mode 100644
index 0000000000000..db1b15f686e32
--- /dev/null
+++ b/arch/x86/entry/vdso/vdso32/fake_32bit_build.h
@@ -0,0 +1,25 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifdef CONFIG_X86_64
+
+/*
+ * in case of a 32 bit VDSO for a 64 bit kernel fake a 32 bit kernel
+ * configuration
+ */
+#undef CONFIG_64BIT
+#undef CONFIG_X86_64
+#undef CONFIG_COMPAT
+#undef CONFIG_PGTABLE_LEVELS
+#undef CONFIG_ILLEGAL_POINTER_VALUE
+#undef CONFIG_SPARSEMEM_VMEMMAP
+#undef CONFIG_NR_CPUS
+#undef CONFIG_PARAVIRT_XXL
+
+#define CONFIG_X86_32 1
+#define CONFIG_PGTABLE_LEVELS 2
+#define CONFIG_PAGE_OFFSET 0
+#define CONFIG_ILLEGAL_POINTER_VALUE 0
+#define CONFIG_NR_CPUS 1
+
+#define BUILD_VDSO32_64
+
+#endif
diff --git a/arch/x86/entry/vdso/vdso32/vclock_gettime.c b/arch/x86/entry/vdso/vdso32/vclock_gettime.c
index 283ed9d004267..86981decfea83 100644
--- a/arch/x86/entry/vdso/vdso32/vclock_gettime.c
+++ b/arch/x86/entry/vdso/vdso32/vclock_gettime.c
@@ -1,29 +1,4 @@
 // SPDX-License-Identifier: GPL-2.0
 #define BUILD_VDSO32
-
-#ifdef CONFIG_X86_64
-
-/*
- * in case of a 32 bit VDSO for a 64 bit kernel fake a 32 bit kernel
- * configuration
- */
-#undef CONFIG_64BIT
-#undef CONFIG_X86_64
-#undef CONFIG_COMPAT
-#undef CONFIG_PGTABLE_LEVELS
-#undef CONFIG_ILLEGAL_POINTER_VALUE
-#undef CONFIG_SPARSEMEM_VMEMMAP
-#undef CONFIG_NR_CPUS
-#undef CONFIG_PARAVIRT_XXL
-
-#define CONFIG_X86_32 1
-#define CONFIG_PGTABLE_LEVELS 2
-#define CONFIG_PAGE_OFFSET 0
-#define CONFIG_ILLEGAL_POINTER_VALUE 0
-#define CONFIG_NR_CPUS 1
-
-#define BUILD_VDSO32_64
-
-#endif
-
+#include "fake_32bit_build.h"
 #include "../vclock_gettime.c"
diff --git a/arch/x86/entry/vdso/vdso32/vgetcpu.c b/arch/x86/entry/vdso/vdso32/vgetcpu.c
index b777f84ffae9b..3a9791f5e9989 100644
--- a/arch/x86/entry/vdso/vdso32/vgetcpu.c
+++ b/arch/x86/entry/vdso/vdso32/vgetcpu.c
@@ -1,2 +1,3 @@
 // SPDX-License-Identifier: GPL-2.0
+#include "fake_32bit_build.h"
 #include "../vgetcpu.c"
-- 
2.39.1


^ permalink raw reply related	[flat|nested] 5+ messages in thread
* Re: [PATCH] x86/vdso: Fake 32bit VDSO build on 64bit compile for vgetcpu.
  2023-02-07 10:46 ` [PATCH] x86/vdso: Fake 32bit VDSO build on 64bit compile for vgetcpu Sebastian Andrzej Siewior
@ 2023-02-07 16:45   ` Damian Tometzki
  2023-02-07 16:53   ` Nathan Chancellor
  2023-02-07 18:31   ` [tip: x86/vdso] " tip-bot2 for Sebastian Andrzej Siewior
  2 siblings, 0 replies; 5+ messages in thread
From: Damian Tometzki @ 2023-02-07 16:45 UTC (permalink / raw)
  To: Sebastian Andrzej Siewior
  Cc: kernel test robot, Nathan Chancellor, Nick Desaulniers, Tom Rix,
	llvm, oe-kbuild-all, linux-kernel, x86, Thomas Gleixner,
	Andy Lutomirski, Ingo Molnar, Borislav Petkov, Dave Hansen,
	H. Peter Anvin

Hello Sebastian,
Linux Kernel build 6.2.0rc7 was successfully with clang-17.

Many Thanks
Damian Tometzki


On Tue, 07. Feb 11:46, Sebastian Andrzej Siewior wrote:
> The 64bit register constrains in __arch_hweight64() can not be
> fulfilled in a 32bit build. The function is only declared, not used
> within vclock_gettime.c and gcc does not care. LLVM complains and
> aborts.
> 
> Move the "fake a 32 bit kernel configuration" bits from vclock_gettime.c
> into a common header file. Use this from vclock_gettime.c and vgetcpu.c.
> 
> Fixes: 92d33063c081a ("x86/vdso: Provide getcpu for x86-32.")
> Reported-by: kernel test robot <lkp@intel.com>
> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
> ---
>  arch/x86/entry/vdso/vdso32/fake_32bit_build.h | 25 +++++++++++++++++
>  arch/x86/entry/vdso/vdso32/vclock_gettime.c   | 27 +------------------
>  arch/x86/entry/vdso/vdso32/vgetcpu.c          |  1 +
>  3 files changed, 27 insertions(+), 26 deletions(-)
>  create mode 100644 arch/x86/entry/vdso/vdso32/fake_32bit_build.h
> 
> diff --git a/arch/x86/entry/vdso/vdso32/fake_32bit_build.h b/arch/x86/entry/vdso/vdso32/fake_32bit_build.h
> new file mode 100644
> index 0000000000000..db1b15f686e32
> --- /dev/null
> +++ b/arch/x86/entry/vdso/vdso32/fake_32bit_build.h
> @@ -0,0 +1,25 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +#ifdef CONFIG_X86_64
> +
> +/*
> + * in case of a 32 bit VDSO for a 64 bit kernel fake a 32 bit kernel
> + * configuration
> + */
> +#undef CONFIG_64BIT
> +#undef CONFIG_X86_64
> +#undef CONFIG_COMPAT
> +#undef CONFIG_PGTABLE_LEVELS
> +#undef CONFIG_ILLEGAL_POINTER_VALUE
> +#undef CONFIG_SPARSEMEM_VMEMMAP
> +#undef CONFIG_NR_CPUS
> +#undef CONFIG_PARAVIRT_XXL
> +
> +#define CONFIG_X86_32 1
> +#define CONFIG_PGTABLE_LEVELS 2
> +#define CONFIG_PAGE_OFFSET 0
> +#define CONFIG_ILLEGAL_POINTER_VALUE 0
> +#define CONFIG_NR_CPUS 1
> +
> +#define BUILD_VDSO32_64
> +
> +#endif
> diff --git a/arch/x86/entry/vdso/vdso32/vclock_gettime.c b/arch/x86/entry/vdso/vdso32/vclock_gettime.c
> index 283ed9d004267..86981decfea83 100644
> --- a/arch/x86/entry/vdso/vdso32/vclock_gettime.c
> +++ b/arch/x86/entry/vdso/vdso32/vclock_gettime.c
> @@ -1,29 +1,4 @@
>  // SPDX-License-Identifier: GPL-2.0
>  #define BUILD_VDSO32
> -
> -#ifdef CONFIG_X86_64
> -
> -/*
> - * in case of a 32 bit VDSO for a 64 bit kernel fake a 32 bit kernel
> - * configuration
> - */
> -#undef CONFIG_64BIT
> -#undef CONFIG_X86_64
> -#undef CONFIG_COMPAT
> -#undef CONFIG_PGTABLE_LEVELS
> -#undef CONFIG_ILLEGAL_POINTER_VALUE
> -#undef CONFIG_SPARSEMEM_VMEMMAP
> -#undef CONFIG_NR_CPUS
> -#undef CONFIG_PARAVIRT_XXL
> -
> -#define CONFIG_X86_32 1
> -#define CONFIG_PGTABLE_LEVELS 2
> -#define CONFIG_PAGE_OFFSET 0
> -#define CONFIG_ILLEGAL_POINTER_VALUE 0
> -#define CONFIG_NR_CPUS 1
> -
> -#define BUILD_VDSO32_64
> -
> -#endif
> -
> +#include "fake_32bit_build.h"
>  #include "../vclock_gettime.c"
> diff --git a/arch/x86/entry/vdso/vdso32/vgetcpu.c b/arch/x86/entry/vdso/vdso32/vgetcpu.c
> index b777f84ffae9b..3a9791f5e9989 100644
> --- a/arch/x86/entry/vdso/vdso32/vgetcpu.c
> +++ b/arch/x86/entry/vdso/vdso32/vgetcpu.c
> @@ -1,2 +1,3 @@
>  // SPDX-License-Identifier: GPL-2.0
> +#include "fake_32bit_build.h"
>  #include "../vgetcpu.c"
> -- 
> 2.39.1
> 

^ permalink raw reply	[flat|nested] 5+ messages in thread
* Re: [PATCH] x86/vdso: Fake 32bit VDSO build on 64bit compile for vgetcpu.
  2023-02-07 10:46 ` [PATCH] x86/vdso: Fake 32bit VDSO build on 64bit compile for vgetcpu Sebastian Andrzej Siewior
  2023-02-07 16:45   ` Damian Tometzki
@ 2023-02-07 16:53   ` Nathan Chancellor
  2023-02-07 18:31   ` [tip: x86/vdso] " tip-bot2 for Sebastian Andrzej Siewior
  2 siblings, 0 replies; 5+ messages in thread
From: Nathan Chancellor @ 2023-02-07 16:53 UTC (permalink / raw)
  To: Sebastian Andrzej Siewior
  Cc: kernel test robot, Nick Desaulniers, Tom Rix, llvm,
	oe-kbuild-all, linux-kernel, x86, Thomas Gleixner,
	Andy Lutomirski, Ingo Molnar, Borislav Petkov, Dave Hansen,
	H. Peter Anvin

On Tue, Feb 07, 2023 at 11:46:33AM +0100, Sebastian Andrzej Siewior wrote:
> The 64bit register constrains in __arch_hweight64() can not be
> fulfilled in a 32bit build. The function is only declared, not used
> within vclock_gettime.c and gcc does not care. LLVM complains and
> aborts.
> 
> Move the "fake a 32 bit kernel configuration" bits from vclock_gettime.c
> into a common header file. Use this from vclock_gettime.c and vgetcpu.c.
> 
> Fixes: 92d33063c081a ("x86/vdso: Provide getcpu for x86-32.")
> Reported-by: kernel test robot <lkp@intel.com>
> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>

Thank you so much for the fix! Boris inquired why this happens with
clang and I wrote a little blurb here if that is helpful at all:

https://lore.kernel.org/Y+J+UQ1vAKr6RHuH@dev-arch.thelio-3990X/

Regardless, this works for me.

Tested-by: Nathan Chancellor <nathan@kernel.org>

> ---
>  arch/x86/entry/vdso/vdso32/fake_32bit_build.h | 25 +++++++++++++++++
>  arch/x86/entry/vdso/vdso32/vclock_gettime.c   | 27 +------------------
>  arch/x86/entry/vdso/vdso32/vgetcpu.c          |  1 +
>  3 files changed, 27 insertions(+), 26 deletions(-)
>  create mode 100644 arch/x86/entry/vdso/vdso32/fake_32bit_build.h
> 
> diff --git a/arch/x86/entry/vdso/vdso32/fake_32bit_build.h b/arch/x86/entry/vdso/vdso32/fake_32bit_build.h
> new file mode 100644
> index 0000000000000..db1b15f686e32
> --- /dev/null
> +++ b/arch/x86/entry/vdso/vdso32/fake_32bit_build.h
> @@ -0,0 +1,25 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +#ifdef CONFIG_X86_64
> +
> +/*
> + * in case of a 32 bit VDSO for a 64 bit kernel fake a 32 bit kernel
> + * configuration
> + */
> +#undef CONFIG_64BIT
> +#undef CONFIG_X86_64
> +#undef CONFIG_COMPAT
> +#undef CONFIG_PGTABLE_LEVELS
> +#undef CONFIG_ILLEGAL_POINTER_VALUE
> +#undef CONFIG_SPARSEMEM_VMEMMAP
> +#undef CONFIG_NR_CPUS
> +#undef CONFIG_PARAVIRT_XXL
> +
> +#define CONFIG_X86_32 1
> +#define CONFIG_PGTABLE_LEVELS 2
> +#define CONFIG_PAGE_OFFSET 0
> +#define CONFIG_ILLEGAL_POINTER_VALUE 0
> +#define CONFIG_NR_CPUS 1
> +
> +#define BUILD_VDSO32_64
> +
> +#endif
> diff --git a/arch/x86/entry/vdso/vdso32/vclock_gettime.c b/arch/x86/entry/vdso/vdso32/vclock_gettime.c
> index 283ed9d004267..86981decfea83 100644
> --- a/arch/x86/entry/vdso/vdso32/vclock_gettime.c
> +++ b/arch/x86/entry/vdso/vdso32/vclock_gettime.c
> @@ -1,29 +1,4 @@
>  // SPDX-License-Identifier: GPL-2.0
>  #define BUILD_VDSO32
> -
> -#ifdef CONFIG_X86_64
> -
> -/*
> - * in case of a 32 bit VDSO for a 64 bit kernel fake a 32 bit kernel
> - * configuration
> - */
> -#undef CONFIG_64BIT
> -#undef CONFIG_X86_64
> -#undef CONFIG_COMPAT
> -#undef CONFIG_PGTABLE_LEVELS
> -#undef CONFIG_ILLEGAL_POINTER_VALUE
> -#undef CONFIG_SPARSEMEM_VMEMMAP
> -#undef CONFIG_NR_CPUS
> -#undef CONFIG_PARAVIRT_XXL
> -
> -#define CONFIG_X86_32 1
> -#define CONFIG_PGTABLE_LEVELS 2
> -#define CONFIG_PAGE_OFFSET 0
> -#define CONFIG_ILLEGAL_POINTER_VALUE 0
> -#define CONFIG_NR_CPUS 1
> -
> -#define BUILD_VDSO32_64
> -
> -#endif
> -
> +#include "fake_32bit_build.h"
>  #include "../vclock_gettime.c"
> diff --git a/arch/x86/entry/vdso/vdso32/vgetcpu.c b/arch/x86/entry/vdso/vdso32/vgetcpu.c
> index b777f84ffae9b..3a9791f5e9989 100644
> --- a/arch/x86/entry/vdso/vdso32/vgetcpu.c
> +++ b/arch/x86/entry/vdso/vdso32/vgetcpu.c
> @@ -1,2 +1,3 @@
>  // SPDX-License-Identifier: GPL-2.0
> +#include "fake_32bit_build.h"
>  #include "../vgetcpu.c"
> -- 
> 2.39.1
> 

^ permalink raw reply	[flat|nested] 5+ messages in thread
* [tip: x86/vdso] x86/vdso: Fake 32bit VDSO build on 64bit compile for vgetcpu
  2023-02-07 10:46 ` [PATCH] x86/vdso: Fake 32bit VDSO build on 64bit compile for vgetcpu Sebastian Andrzej Siewior
  2023-02-07 16:45   ` Damian Tometzki
  2023-02-07 16:53   ` Nathan Chancellor
@ 2023-02-07 18:31   ` tip-bot2 for Sebastian Andrzej Siewior
  2 siblings, 0 replies; 5+ messages in thread
From: tip-bot2 for Sebastian Andrzej Siewior @ 2023-02-07 18:31 UTC (permalink / raw)
  To: linux-tip-commits
  Cc: kernel test robot, Sebastian Andrzej Siewior,
	Borislav Petkov (AMD),
	x86, linux-kernel

The following commit has been merged into the x86/vdso branch of tip:

Commit-ID:     877cff5296faa6ef312f8002216bbf73bea006c7
Gitweb:        https://git.kernel.org/tip/877cff5296faa6ef312f8002216bbf73bea006c7
Author:        Sebastian Andrzej Siewior <bigeasy@linutronix.de>
AuthorDate:    Tue, 07 Feb 2023 11:46:33 +01:00
Committer:     Borislav Petkov (AMD) <bp@alien8.de>
CommitterDate: Tue, 07 Feb 2023 18:20:41 +01:00

x86/vdso: Fake 32bit VDSO build on 64bit compile for vgetcpu

The 64bit register constrains in __arch_hweight64() cannot be
fulfilled in a 32-bit build. The function is only declared but not used
within vclock_gettime.c and gcc does not care. LLVM complains and
aborts. Reportedly because it validates extended asm even if latter
would get compiled out, see

  https://lore.kernel.org/r/Y%2BJ%2BUQ1vAKr6RHuH@dev-arch.thelio-3990X

i.e., a long standing design difference between gcc and LLVM.

Move the "fake a 32 bit kernel configuration" bits from vclock_gettime.c
into a common header file. Use this from vclock_gettime.c and vgetcpu.c.

  [ bp: Add background info from Nathan. ]

Fixes: 92d33063c081a ("x86/vdso: Provide getcpu for x86-32.")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/Y+IsCWQdXEr8d9Vy@linutronix.de
---
 arch/x86/entry/vdso/vdso32/fake_32bit_build.h | 25 +++++++++++++++++-
 arch/x86/entry/vdso/vdso32/vclock_gettime.c   | 27 +------------------
 arch/x86/entry/vdso/vdso32/vgetcpu.c          |  1 +-
 3 files changed, 27 insertions(+), 26 deletions(-)
 create mode 100644 arch/x86/entry/vdso/vdso32/fake_32bit_build.h

diff --git a/arch/x86/entry/vdso/vdso32/fake_32bit_build.h b/arch/x86/entry/vdso/vdso32/fake_32bit_build.h
new file mode 100644
index 0000000..db1b15f
--- /dev/null
+++ b/arch/x86/entry/vdso/vdso32/fake_32bit_build.h
@@ -0,0 +1,25 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifdef CONFIG_X86_64
+
+/*
+ * in case of a 32 bit VDSO for a 64 bit kernel fake a 32 bit kernel
+ * configuration
+ */
+#undef CONFIG_64BIT
+#undef CONFIG_X86_64
+#undef CONFIG_COMPAT
+#undef CONFIG_PGTABLE_LEVELS
+#undef CONFIG_ILLEGAL_POINTER_VALUE
+#undef CONFIG_SPARSEMEM_VMEMMAP
+#undef CONFIG_NR_CPUS
+#undef CONFIG_PARAVIRT_XXL
+
+#define CONFIG_X86_32 1
+#define CONFIG_PGTABLE_LEVELS 2
+#define CONFIG_PAGE_OFFSET 0
+#define CONFIG_ILLEGAL_POINTER_VALUE 0
+#define CONFIG_NR_CPUS 1
+
+#define BUILD_VDSO32_64
+
+#endif
diff --git a/arch/x86/entry/vdso/vdso32/vclock_gettime.c b/arch/x86/entry/vdso/vdso32/vclock_gettime.c
index 283ed9d..86981de 100644
--- a/arch/x86/entry/vdso/vdso32/vclock_gettime.c
+++ b/arch/x86/entry/vdso/vdso32/vclock_gettime.c
@@ -1,29 +1,4 @@
 // SPDX-License-Identifier: GPL-2.0
 #define BUILD_VDSO32
-
-#ifdef CONFIG_X86_64
-
-/*
- * in case of a 32 bit VDSO for a 64 bit kernel fake a 32 bit kernel
- * configuration
- */
-#undef CONFIG_64BIT
-#undef CONFIG_X86_64
-#undef CONFIG_COMPAT
-#undef CONFIG_PGTABLE_LEVELS
-#undef CONFIG_ILLEGAL_POINTER_VALUE
-#undef CONFIG_SPARSEMEM_VMEMMAP
-#undef CONFIG_NR_CPUS
-#undef CONFIG_PARAVIRT_XXL
-
-#define CONFIG_X86_32 1
-#define CONFIG_PGTABLE_LEVELS 2
-#define CONFIG_PAGE_OFFSET 0
-#define CONFIG_ILLEGAL_POINTER_VALUE 0
-#define CONFIG_NR_CPUS 1
-
-#define BUILD_VDSO32_64
-
-#endif
-
+#include "fake_32bit_build.h"
 #include "../vclock_gettime.c"
diff --git a/arch/x86/entry/vdso/vdso32/vgetcpu.c b/arch/x86/entry/vdso/vdso32/vgetcpu.c
index b777f84..3a9791f 100644
--- a/arch/x86/entry/vdso/vdso32/vgetcpu.c
+++ b/arch/x86/entry/vdso/vdso32/vgetcpu.c
@@ -1,2 +1,3 @@
 // SPDX-License-Identifier: GPL-2.0
+#include "fake_32bit_build.h"
 #include "../vgetcpu.c"

^ permalink raw reply related	[flat|nested] 5+ messages in thread
end of thread, other threads:[~2023-02-07 18:32 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2023-02-07  5:39 [tip:x86/vdso 3/4] arch/x86/include/asm/arch_hweight.h:49:15: error: invalid input size for constraint 'D' kernel test robot
2023-02-07 10:46 ` [PATCH] x86/vdso: Fake 32bit VDSO build on 64bit compile for vgetcpu Sebastian Andrzej Siewior
2023-02-07 16:45   ` Damian Tometzki
2023-02-07 16:53   ` Nathan Chancellor
2023-02-07 18:31   ` [tip: x86/vdso] " tip-bot2 for Sebastian Andrzej Siewior

This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.