Messages in this thread | | | Subject | Re: [PATCH v9 7/7] powerpc: add machine check safe copy_to_user | From | Balbir Singh <> | Date | Wed, 14 Aug 2019 19:40:58 +1000 |
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On 12/8/19 7:22 pm, Santosh Sivaraj wrote: > Use memcpy_mcsafe() implementation to define copy_to_user_mcsafe() > > Signed-off-by: Santosh Sivaraj <santosh@fossix.org> > --- > arch/powerpc/Kconfig | 1 + > arch/powerpc/include/asm/uaccess.h | 14 ++++++++++++++ > 2 files changed, 15 insertions(+) > > diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig > index 77f6ebf97113..4316e36095a2 100644 > --- a/arch/powerpc/Kconfig > +++ b/arch/powerpc/Kconfig > @@ -137,6 +137,7 @@ config PPC > select ARCH_HAS_STRICT_KERNEL_RWX if ((PPC_BOOK3S_64 || PPC32) && !RELOCATABLE && !HIBERNATION) > select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST > select ARCH_HAS_UACCESS_FLUSHCACHE if PPC64 > + select ARCH_HAS_UACCESS_MCSAFE if PPC64 > select ARCH_HAS_UBSAN_SANITIZE_ALL > select ARCH_HAVE_NMI_SAFE_CMPXCHG > select ARCH_KEEP_MEMBLOCK > diff --git a/arch/powerpc/include/asm/uaccess.h b/arch/powerpc/include/asm/uaccess.h > index 8b03eb44e876..15002b51ff18 100644 > --- a/arch/powerpc/include/asm/uaccess.h > +++ b/arch/powerpc/include/asm/uaccess.h > @@ -387,6 +387,20 @@ static inline unsigned long raw_copy_to_user(void __user *to, > return ret; > } > > +static __always_inline unsigned long __must_check > +copy_to_user_mcsafe(void __user *to, const void *from, unsigned long n) > +{ > + if (likely(check_copy_size(from, n, true))) { > + if (access_ok(to, n)) { > + allow_write_to_user(to, n); > + n = memcpy_mcsafe((void *)to, from, n); > + prevent_write_to_user(to, n); > + } > + } > + > + return n;
Do we always return n independent of the check_copy_size return value and access_ok return values?
Balbir Singh.
> +} > + > extern unsigned long __clear_user(void __user *addr, unsigned long size); > > static inline unsigned long clear_user(void __user *addr, unsigned long size) >
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