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| author | Sebastian Andrzej Siewior <bigeasy@linutronix.de> | 2023-02-07 11:46:33 +0100 |
|---|---|---|
| committer | Borislav Petkov (AMD) <bp@alien8.de> | 2023-02-07 18:20:41 +0100 |
| commit | 877cff5296faa6ef312f8002216bbf73bea006c7 (patch) | |
| tree | eea8bdb0d80b396f147f917dbabc3e6e2b5ca1c7 /arch/x86/entry | |
| parent | 5646bbd6684acf5c9b9dedb863b7d2f6f5a330fb (diff) | |
| download | linux-877cff5296faa6ef312f8002216bbf73bea006c7.tar.gz linux-877cff5296faa6ef312f8002216bbf73bea006c7.tar.bz2 linux-877cff5296faa6ef312f8002216bbf73bea006c7.zip | |
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
Diffstat (limited to 'arch/x86/entry')
| -rw-r--r-- | arch/x86/entry/vdso/vdso32/fake_32bit_build.h | 25 | ||||
| -rw-r--r-- | arch/x86/entry/vdso/vdso32/vclock_gettime.c | 27 | ||||
| -rw-r--r-- | arch/x86/entry/vdso/vdso32/vgetcpu.c | 1 |
3 files changed, 27 insertions, 26 deletions
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 000000000000..db1b15f686e3 --- /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 283ed9d00426..86981decfea8 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 b777f84ffae9..3a9791f5e998 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" |