| Message ID | 20220211182215.2730017-2-scgl@linux.ibm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | KVM: s390: Do storage key checking | expand |
On Fri, 11 Feb 2022 19:22:06 +0100 Janis Schoetterl-Glausch <scgl@linux.ibm.com> wrote: > Add copy_from/to_user_key functions, which perform storage key checking. > These functions can be used by KVM for emulating instructions that need > to be key checked. > These functions differ from their non _key counterparts in > include/linux/uaccess.h only in the additional key argument and must be > kept in sync with those. > > Since the existing uaccess implementation on s390 makes use of move > instructions that support having an additional access key supplied, > we can implement raw_copy_from/to_user_key by enhancing the > existing implementation. > > Signed-off-by: Janis Schoetterl-Glausch <scgl@linux.ibm.com> > Acked-by: Heiko Carstens <hca@linux.ibm.com> > Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com> > Acked-by: Janosch Frank <frankja@linux.ibm.com> Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> > --- > arch/s390/include/asm/uaccess.h | 22 +++++++++ > arch/s390/lib/uaccess.c | 81 +++++++++++++++++++++++++-------- > 2 files changed, 85 insertions(+), 18 deletions(-) > > diff --git a/arch/s390/include/asm/uaccess.h b/arch/s390/include/asm/uaccess.h > index d74e26b48604..ba1bcb91af95 100644 > --- a/arch/s390/include/asm/uaccess.h > +++ b/arch/s390/include/asm/uaccess.h > @@ -44,6 +44,28 @@ raw_copy_to_user(void __user *to, const void *from, unsigned long n); > #define INLINE_COPY_TO_USER > #endif > > +unsigned long __must_check > +_copy_from_user_key(void *to, const void __user *from, unsigned long n, unsigned long key); > + > +static __always_inline unsigned long __must_check > +copy_from_user_key(void *to, const void __user *from, unsigned long n, unsigned long key) > +{ > + if (likely(check_copy_size(to, n, false))) > + n = _copy_from_user_key(to, from, n, key); > + return n; > +} > + > +unsigned long __must_check > +_copy_to_user_key(void __user *to, const void *from, unsigned long n, unsigned long key); > + > +static __always_inline unsigned long __must_check > +copy_to_user_key(void __user *to, const void *from, unsigned long n, unsigned long key) > +{ > + if (likely(check_copy_size(from, n, true))) > + n = _copy_to_user_key(to, from, n, key); > + return n; > +} > + > int __put_user_bad(void) __attribute__((noreturn)); > int __get_user_bad(void) __attribute__((noreturn)); > > diff --git a/arch/s390/lib/uaccess.c b/arch/s390/lib/uaccess.c > index 8a5d21461889..b709239feb5d 100644 > --- a/arch/s390/lib/uaccess.c > +++ b/arch/s390/lib/uaccess.c > @@ -59,11 +59,13 @@ static inline int copy_with_mvcos(void) > #endif > > static inline unsigned long copy_from_user_mvcos(void *x, const void __user *ptr, > - unsigned long size) > + unsigned long size, unsigned long key) > { > unsigned long tmp1, tmp2; > union oac spec = { > + .oac2.key = key, > .oac2.as = PSW_BITS_AS_SECONDARY, > + .oac2.k = 1, > .oac2.a = 1, > }; > > @@ -94,19 +96,19 @@ static inline unsigned long copy_from_user_mvcos(void *x, const void __user *ptr > } > > static inline unsigned long copy_from_user_mvcp(void *x, const void __user *ptr, > - unsigned long size) > + unsigned long size, unsigned long key) > { > unsigned long tmp1, tmp2; > > tmp1 = -256UL; > asm volatile( > " sacf 0\n" > - "0: mvcp 0(%0,%2),0(%1),%3\n" > + "0: mvcp 0(%0,%2),0(%1),%[key]\n" > "7: jz 5f\n" > "1: algr %0,%3\n" > " la %1,256(%1)\n" > " la %2,256(%2)\n" > - "2: mvcp 0(%0,%2),0(%1),%3\n" > + "2: mvcp 0(%0,%2),0(%1),%[key]\n" > "8: jnz 1b\n" > " j 5f\n" > "3: la %4,255(%1)\n" /* %4 = ptr + 255 */ > @@ -115,7 +117,7 @@ static inline unsigned long copy_from_user_mvcp(void *x, const void __user *ptr, > " slgr %4,%1\n" > " clgr %0,%4\n" /* copy crosses next page boundary? */ > " jnh 6f\n" > - "4: mvcp 0(%4,%2),0(%1),%3\n" > + "4: mvcp 0(%4,%2),0(%1),%[key]\n" > "9: slgr %0,%4\n" > " j 6f\n" > "5: slgr %0,%0\n" > @@ -123,24 +125,49 @@ static inline unsigned long copy_from_user_mvcp(void *x, const void __user *ptr, > EX_TABLE(0b,3b) EX_TABLE(2b,3b) EX_TABLE(4b,6b) > EX_TABLE(7b,3b) EX_TABLE(8b,3b) EX_TABLE(9b,6b) > : "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2) > - : : "cc", "memory"); > + : [key] "d" (key << 4) > + : "cc", "memory"); > return size; > } > > -unsigned long raw_copy_from_user(void *to, const void __user *from, unsigned long n) > +static unsigned long raw_copy_from_user_key(void *to, const void __user *from, > + unsigned long n, unsigned long key) > { > if (copy_with_mvcos()) > - return copy_from_user_mvcos(to, from, n); > - return copy_from_user_mvcp(to, from, n); > + return copy_from_user_mvcos(to, from, n, key); > + return copy_from_user_mvcp(to, from, n, key); > +} > + > +unsigned long raw_copy_from_user(void *to, const void __user *from, unsigned long n) > +{ > + return raw_copy_from_user_key(to, from, n, 0); > } > EXPORT_SYMBOL(raw_copy_from_user); > > +unsigned long _copy_from_user_key(void *to, const void __user *from, > + unsigned long n, unsigned long key) > +{ > + unsigned long res = n; > + > + might_fault(); > + if (!should_fail_usercopy()) { > + instrument_copy_from_user(to, from, n); > + res = raw_copy_from_user_key(to, from, n, key); > + } > + if (unlikely(res)) > + memset(to + (n - res), 0, res); > + return res; > +} > +EXPORT_SYMBOL(_copy_from_user_key); > + > static inline unsigned long copy_to_user_mvcos(void __user *ptr, const void *x, > - unsigned long size) > + unsigned long size, unsigned long key) > { > unsigned long tmp1, tmp2; > union oac spec = { > + .oac1.key = key, > .oac1.as = PSW_BITS_AS_SECONDARY, > + .oac1.k = 1, > .oac1.a = 1, > }; > > @@ -171,19 +198,19 @@ static inline unsigned long copy_to_user_mvcos(void __user *ptr, const void *x, > } > > static inline unsigned long copy_to_user_mvcs(void __user *ptr, const void *x, > - unsigned long size) > + unsigned long size, unsigned long key) > { > unsigned long tmp1, tmp2; > > tmp1 = -256UL; > asm volatile( > " sacf 0\n" > - "0: mvcs 0(%0,%1),0(%2),%3\n" > + "0: mvcs 0(%0,%1),0(%2),%[key]\n" > "7: jz 5f\n" > "1: algr %0,%3\n" > " la %1,256(%1)\n" > " la %2,256(%2)\n" > - "2: mvcs 0(%0,%1),0(%2),%3\n" > + "2: mvcs 0(%0,%1),0(%2),%[key]\n" > "8: jnz 1b\n" > " j 5f\n" > "3: la %4,255(%1)\n" /* %4 = ptr + 255 */ > @@ -192,7 +219,7 @@ static inline unsigned long copy_to_user_mvcs(void __user *ptr, const void *x, > " slgr %4,%1\n" > " clgr %0,%4\n" /* copy crosses next page boundary? */ > " jnh 6f\n" > - "4: mvcs 0(%4,%1),0(%2),%3\n" > + "4: mvcs 0(%4,%1),0(%2),%[key]\n" > "9: slgr %0,%4\n" > " j 6f\n" > "5: slgr %0,%0\n" > @@ -200,18 +227,36 @@ static inline unsigned long copy_to_user_mvcs(void __user *ptr, const void *x, > EX_TABLE(0b,3b) EX_TABLE(2b,3b) EX_TABLE(4b,6b) > EX_TABLE(7b,3b) EX_TABLE(8b,3b) EX_TABLE(9b,6b) > : "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2) > - : : "cc", "memory"); > + : [key] "d" (key << 4) > + : "cc", "memory"); > return size; > } > > -unsigned long raw_copy_to_user(void __user *to, const void *from, unsigned long n) > +static unsigned long raw_copy_to_user_key(void __user *to, const void *from, > + unsigned long n, unsigned long key) > { > if (copy_with_mvcos()) > - return copy_to_user_mvcos(to, from, n); > - return copy_to_user_mvcs(to, from, n); > + return copy_to_user_mvcos(to, from, n, key); > + return copy_to_user_mvcs(to, from, n, key); > +} > + > +unsigned long raw_copy_to_user(void __user *to, const void *from, unsigned long n) > +{ > + return raw_copy_to_user_key(to, from, n, 0); > } > EXPORT_SYMBOL(raw_copy_to_user); > > +unsigned long _copy_to_user_key(void __user *to, const void *from, > + unsigned long n, unsigned long key) > +{ > + might_fault(); > + if (should_fail_usercopy()) > + return n; > + instrument_copy_to_user(to, from, n); > + return raw_copy_to_user_key(to, from, n, key); > +} > +EXPORT_SYMBOL(_copy_to_user_key); > + > static inline unsigned long clear_user_mvcos(void __user *to, unsigned long size) > { > unsigned long tmp1, tmp2;
diff --git a/arch/s390/include/asm/uaccess.h b/arch/s390/include/asm/uaccess.h index d74e26b48604..ba1bcb91af95 100644 --- a/arch/s390/include/asm/uaccess.h +++ b/arch/s390/include/asm/uaccess.h @@ -44,6 +44,28 @@ raw_copy_to_user(void __user *to, const void *from, unsigned long n); #define INLINE_COPY_TO_USER #endif +unsigned long __must_check +_copy_from_user_key(void *to, const void __user *from, unsigned long n, unsigned long key); + +static __always_inline unsigned long __must_check +copy_from_user_key(void *to, const void __user *from, unsigned long n, unsigned long key) +{ + if (likely(check_copy_size(to, n, false))) + n = _copy_from_user_key(to, from, n, key); + return n; +} + +unsigned long __must_check +_copy_to_user_key(void __user *to, const void *from, unsigned long n, unsigned long key); + +static __always_inline unsigned long __must_check +copy_to_user_key(void __user *to, const void *from, unsigned long n, unsigned long key) +{ + if (likely(check_copy_size(from, n, true))) + n = _copy_to_user_key(to, from, n, key); + return n; +} + int __put_user_bad(void) __attribute__((noreturn)); int __get_user_bad(void) __attribute__((noreturn)); diff --git a/arch/s390/lib/uaccess.c b/arch/s390/lib/uaccess.c index 8a5d21461889..b709239feb5d 100644 --- a/arch/s390/lib/uaccess.c +++ b/arch/s390/lib/uaccess.c @@ -59,11 +59,13 @@ static inline int copy_with_mvcos(void) #endif static inline unsigned long copy_from_user_mvcos(void *x, const void __user *ptr, - unsigned long size) + unsigned long size, unsigned long key) { unsigned long tmp1, tmp2; union oac spec = { + .oac2.key = key, .oac2.as = PSW_BITS_AS_SECONDARY, + .oac2.k = 1, .oac2.a = 1, }; @@ -94,19 +96,19 @@ static inline unsigned long copy_from_user_mvcos(void *x, const void __user *ptr } static inline unsigned long copy_from_user_mvcp(void *x, const void __user *ptr, - unsigned long size) + unsigned long size, unsigned long key) { unsigned long tmp1, tmp2; tmp1 = -256UL; asm volatile( " sacf 0\n" - "0: mvcp 0(%0,%2),0(%1),%3\n" + "0: mvcp 0(%0,%2),0(%1),%[key]\n" "7: jz 5f\n" "1: algr %0,%3\n" " la %1,256(%1)\n" " la %2,256(%2)\n" - "2: mvcp 0(%0,%2),0(%1),%3\n" + "2: mvcp 0(%0,%2),0(%1),%[key]\n" "8: jnz 1b\n" " j 5f\n" "3: la %4,255(%1)\n" /* %4 = ptr + 255 */ @@ -115,7 +117,7 @@ static inline unsigned long copy_from_user_mvcp(void *x, const void __user *ptr, " slgr %4,%1\n" " clgr %0,%4\n" /* copy crosses next page boundary? */ " jnh 6f\n" - "4: mvcp 0(%4,%2),0(%1),%3\n" + "4: mvcp 0(%4,%2),0(%1),%[key]\n" "9: slgr %0,%4\n" " j 6f\n" "5: slgr %0,%0\n" @@ -123,24 +125,49 @@ static inline unsigned long copy_from_user_mvcp(void *x, const void __user *ptr, EX_TABLE(0b,3b) EX_TABLE(2b,3b) EX_TABLE(4b,6b) EX_TABLE(7b,3b) EX_TABLE(8b,3b) EX_TABLE(9b,6b) : "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2) - : : "cc", "memory"); + : [key] "d" (key << 4) + : "cc", "memory"); return size; } -unsigned long raw_copy_from_user(void *to, const void __user *from, unsigned long n) +static unsigned long raw_copy_from_user_key(void *to, const void __user *from, + unsigned long n, unsigned long key) { if (copy_with_mvcos()) - return copy_from_user_mvcos(to, from, n); - return copy_from_user_mvcp(to, from, n); + return copy_from_user_mvcos(to, from, n, key); + return copy_from_user_mvcp(to, from, n, key); +} + +unsigned long raw_copy_from_user(void *to, const void __user *from, unsigned long n) +{ + return raw_copy_from_user_key(to, from, n, 0); } EXPORT_SYMBOL(raw_copy_from_user); +unsigned long _copy_from_user_key(void *to, const void __user *from, + unsigned long n, unsigned long key) +{ + unsigned long res = n; + + might_fault(); + if (!should_fail_usercopy()) { + instrument_copy_from_user(to, from, n); + res = raw_copy_from_user_key(to, from, n, key); + } + if (unlikely(res)) + memset(to + (n - res), 0, res); + return res; +} +EXPORT_SYMBOL(_copy_from_user_key); + static inline unsigned long copy_to_user_mvcos(void __user *ptr, const void *x, - unsigned long size) + unsigned long size, unsigned long key) { unsigned long tmp1, tmp2; union oac spec = { + .oac1.key = key, .oac1.as = PSW_BITS_AS_SECONDARY, + .oac1.k = 1, .oac1.a = 1, }; @@ -171,19 +198,19 @@ static inline unsigned long copy_to_user_mvcos(void __user *ptr, const void *x, } static inline unsigned long copy_to_user_mvcs(void __user *ptr, const void *x, - unsigned long size) + unsigned long size, unsigned long key) { unsigned long tmp1, tmp2; tmp1 = -256UL; asm volatile( " sacf 0\n" - "0: mvcs 0(%0,%1),0(%2),%3\n" + "0: mvcs 0(%0,%1),0(%2),%[key]\n" "7: jz 5f\n" "1: algr %0,%3\n" " la %1,256(%1)\n" " la %2,256(%2)\n" - "2: mvcs 0(%0,%1),0(%2),%3\n" + "2: mvcs 0(%0,%1),0(%2),%[key]\n" "8: jnz 1b\n" " j 5f\n" "3: la %4,255(%1)\n" /* %4 = ptr + 255 */ @@ -192,7 +219,7 @@ static inline unsigned long copy_to_user_mvcs(void __user *ptr, const void *x, " slgr %4,%1\n" " clgr %0,%4\n" /* copy crosses next page boundary? */ " jnh 6f\n" - "4: mvcs 0(%4,%1),0(%2),%3\n" + "4: mvcs 0(%4,%1),0(%2),%[key]\n" "9: slgr %0,%4\n" " j 6f\n" "5: slgr %0,%0\n" @@ -200,18 +227,36 @@ static inline unsigned long copy_to_user_mvcs(void __user *ptr, const void *x, EX_TABLE(0b,3b) EX_TABLE(2b,3b) EX_TABLE(4b,6b) EX_TABLE(7b,3b) EX_TABLE(8b,3b) EX_TABLE(9b,6b) : "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2) - : : "cc", "memory"); + : [key] "d" (key << 4) + : "cc", "memory"); return size; } -unsigned long raw_copy_to_user(void __user *to, const void *from, unsigned long n) +static unsigned long raw_copy_to_user_key(void __user *to, const void *from, + unsigned long n, unsigned long key) { if (copy_with_mvcos()) - return copy_to_user_mvcos(to, from, n); - return copy_to_user_mvcs(to, from, n); + return copy_to_user_mvcos(to, from, n, key); + return copy_to_user_mvcs(to, from, n, key); +} + +unsigned long raw_copy_to_user(void __user *to, const void *from, unsigned long n) +{ + return raw_copy_to_user_key(to, from, n, 0); } EXPORT_SYMBOL(raw_copy_to_user); +unsigned long _copy_to_user_key(void __user *to, const void *from, + unsigned long n, unsigned long key) +{ + might_fault(); + if (should_fail_usercopy()) + return n; + instrument_copy_to_user(to, from, n); + return raw_copy_to_user_key(to, from, n, key); +} +EXPORT_SYMBOL(_copy_to_user_key); + static inline unsigned long clear_user_mvcos(void __user *to, unsigned long size) { unsigned long tmp1, tmp2;