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| author | Arnd Bergmann <arnd@arndb.de> | 2019-10-01 16:23:35 +0200 |
|---|---|---|
| committer | Borislav Petkov <bp@suse.de> | 2019-10-03 10:51:17 +0200 |
| commit | 87d6021b814353d7b353afcc3698ffe49de7d4ec (patch) | |
| tree | 6d511c8c400caacd3b5b7cc5125a0a78eed67f77 /arch/x86/Kconfig | |
| parent | e6b44ce1925a8329a937c57f0d60ba0d9bb5d226 (diff) | |
| download | linux-87d6021b814353d7b353afcc3698ffe49de7d4ec.tar.bz2 | |
x86/math-emu: Limit MATH_EMULATION to 486SX compatibles
The FPU emulation code is old and fragile in places, try to limit its
use to builds for CPUs that actually use it. As far as I can tell,
this is only true for i486sx compatibles, including the Cyrix 486SLC,
AMD Am486SX and ÉLAN SC410, UMC U5S amd DM&P VortexSX86, all of which
were relatively short-lived and got replaced with i486DX compatible
processors soon after introduction, though some of the embedded versions
remained available much longer.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Bill Metzenthen <billm@melbpc.org.au>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20191001142344.1274185-2-arnd@arndb.de
Diffstat (limited to 'arch/x86/Kconfig')
| -rw-r--r-- | arch/x86/Kconfig | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index d6e1faa28c58..91c22ee6bc9a 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -1751,7 +1751,7 @@ config X86_RESERVE_LOW config MATH_EMULATION bool depends on MODIFY_LDT_SYSCALL - prompt "Math emulation" if X86_32 + prompt "Math emulation" if X86_32 && (M486SX || MELAN) ---help--- Linux can emulate a math coprocessor (used for floating point operations) if you don't have one. 486DX and Pentium processors have |