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s390/cpacf: get rid of register asm
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Using register asm statements has been proven to be very error prone,
especially when using code instrumentation where gcc may add function
calls, which clobbers register contents in an unexpected way.

Therefore get rid of register asm statements in cpacf code, and make
sure this bug class cannot happen.

Reviewed-by: Patrick Steuer <patrick.steuer@de.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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Heiko Carstens committed Jul 27, 2021
1 parent b49d08a commit b84d0c4
Showing 1 changed file with 111 additions and 97 deletions.
208 changes: 111 additions & 97 deletions arch/s390/include/asm/cpacf.h
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Original file line number Diff line number Diff line change
Expand Up @@ -173,17 +173,16 @@ typedef struct { unsigned char bytes[16]; } cpacf_mask_t;
*/
static __always_inline void __cpacf_query(unsigned int opcode, cpacf_mask_t *mask)
{
register unsigned long r0 asm("0") = 0; /* query function */
register unsigned long r1 asm("1") = (unsigned long) mask;

asm volatile(
" spm 0\n" /* pckmo doesn't change the cc */
" lghi 0,0\n" /* query function */
" lgr 1,%[mask]\n"
" spm 0\n" /* pckmo doesn't change the cc */
/* Parameter regs are ignored, but must be nonzero and unique */
"0: .insn rrf,%[opc] << 16,2,4,6,0\n"
" brc 1,0b\n" /* handle partial completion */
: "=m" (*mask)
: [fc] "d" (r0), [pba] "a" (r1), [opc] "i" (opcode)
: "cc");
: [mask] "d" ((unsigned long)mask), [opc] "i" (opcode)
: "cc", "0", "1");
}

static __always_inline int __cpacf_check_opcode(unsigned int opcode)
Expand Down Expand Up @@ -249,20 +248,22 @@ static __always_inline int cpacf_query_func(unsigned int opcode, unsigned int fu
static inline int cpacf_km(unsigned long func, void *param,
u8 *dest, const u8 *src, long src_len)
{
register unsigned long r0 asm("0") = (unsigned long) func;
register unsigned long r1 asm("1") = (unsigned long) param;
register unsigned long r2 asm("2") = (unsigned long) src;
register unsigned long r3 asm("3") = (unsigned long) src_len;
register unsigned long r4 asm("4") = (unsigned long) dest;
union register_pair d, s;

d.even = (unsigned long)dest;
s.even = (unsigned long)src;
s.odd = (unsigned long)src_len;
asm volatile(
" lgr 0,%[fc]\n"
" lgr 1,%[pba]\n"
"0: .insn rre,%[opc] << 16,%[dst],%[src]\n"
" brc 1,0b\n" /* handle partial completion */
: [src] "+a" (r2), [len] "+d" (r3), [dst] "+a" (r4)
: [fc] "d" (r0), [pba] "a" (r1), [opc] "i" (CPACF_KM)
: "cc", "memory");
: [src] "+&d" (s.pair), [dst] "+&d" (d.pair)
: [fc] "d" (func), [pba] "d" ((unsigned long)param),
[opc] "i" (CPACF_KM)
: "cc", "memory", "0", "1");

return src_len - r3;
return src_len - s.odd;
}

/**
Expand All @@ -279,20 +280,22 @@ static inline int cpacf_km(unsigned long func, void *param,
static inline int cpacf_kmc(unsigned long func, void *param,
u8 *dest, const u8 *src, long src_len)
{
register unsigned long r0 asm("0") = (unsigned long) func;
register unsigned long r1 asm("1") = (unsigned long) param;
register unsigned long r2 asm("2") = (unsigned long) src;
register unsigned long r3 asm("3") = (unsigned long) src_len;
register unsigned long r4 asm("4") = (unsigned long) dest;
union register_pair d, s;

d.even = (unsigned long)dest;
s.even = (unsigned long)src;
s.odd = (unsigned long)src_len;
asm volatile(
" lgr 0,%[fc]\n"
" lgr 1,%[pba]\n"
"0: .insn rre,%[opc] << 16,%[dst],%[src]\n"
" brc 1,0b\n" /* handle partial completion */
: [src] "+a" (r2), [len] "+d" (r3), [dst] "+a" (r4)
: [fc] "d" (r0), [pba] "a" (r1), [opc] "i" (CPACF_KMC)
: "cc", "memory");
: [src] "+&d" (s.pair), [dst] "+&d" (d.pair)
: [fc] "d" (func), [pba] "d" ((unsigned long)param),
[opc] "i" (CPACF_KMC)
: "cc", "memory", "0", "1");

return src_len - r3;
return src_len - s.odd;
}

/**
Expand All @@ -306,17 +309,19 @@ static inline int cpacf_kmc(unsigned long func, void *param,
static inline void cpacf_kimd(unsigned long func, void *param,
const u8 *src, long src_len)
{
register unsigned long r0 asm("0") = (unsigned long) func;
register unsigned long r1 asm("1") = (unsigned long) param;
register unsigned long r2 asm("2") = (unsigned long) src;
register unsigned long r3 asm("3") = (unsigned long) src_len;
union register_pair s;

s.even = (unsigned long)src;
s.odd = (unsigned long)src_len;
asm volatile(
" lgr 0,%[fc]\n"
" lgr 1,%[pba]\n"
"0: .insn rre,%[opc] << 16,0,%[src]\n"
" brc 1,0b\n" /* handle partial completion */
: [src] "+a" (r2), [len] "+d" (r3)
: [fc] "d" (r0), [pba] "a" (r1), [opc] "i" (CPACF_KIMD)
: "cc", "memory");
: [src] "+&d" (s.pair)
: [fc] "d" (func), [pba] "d" ((unsigned long)(param)),
[opc] "i" (CPACF_KIMD)
: "cc", "memory", "0", "1");
}

/**
Expand All @@ -329,17 +334,19 @@ static inline void cpacf_kimd(unsigned long func, void *param,
static inline void cpacf_klmd(unsigned long func, void *param,
const u8 *src, long src_len)
{
register unsigned long r0 asm("0") = (unsigned long) func;
register unsigned long r1 asm("1") = (unsigned long) param;
register unsigned long r2 asm("2") = (unsigned long) src;
register unsigned long r3 asm("3") = (unsigned long) src_len;
union register_pair s;

s.even = (unsigned long)src;
s.odd = (unsigned long)src_len;
asm volatile(
" lgr 0,%[fc]\n"
" lgr 1,%[pba]\n"
"0: .insn rre,%[opc] << 16,0,%[src]\n"
" brc 1,0b\n" /* handle partial completion */
: [src] "+a" (r2), [len] "+d" (r3)
: [fc] "d" (r0), [pba] "a" (r1), [opc] "i" (CPACF_KLMD)
: "cc", "memory");
: [src] "+&d" (s.pair)
: [fc] "d" (func), [pba] "d" ((unsigned long)param),
[opc] "i" (CPACF_KLMD)
: "cc", "memory", "0", "1");
}

/**
Expand All @@ -355,19 +362,21 @@ static inline void cpacf_klmd(unsigned long func, void *param,
static inline int cpacf_kmac(unsigned long func, void *param,
const u8 *src, long src_len)
{
register unsigned long r0 asm("0") = (unsigned long) func;
register unsigned long r1 asm("1") = (unsigned long) param;
register unsigned long r2 asm("2") = (unsigned long) src;
register unsigned long r3 asm("3") = (unsigned long) src_len;
union register_pair s;

s.even = (unsigned long)src;
s.odd = (unsigned long)src_len;
asm volatile(
" lgr 0,%[fc]\n"
" lgr 1,%[pba]\n"
"0: .insn rre,%[opc] << 16,0,%[src]\n"
" brc 1,0b\n" /* handle partial completion */
: [src] "+a" (r2), [len] "+d" (r3)
: [fc] "d" (r0), [pba] "a" (r1), [opc] "i" (CPACF_KMAC)
: "cc", "memory");
: [src] "+&d" (s.pair)
: [fc] "d" (func), [pba] "d" ((unsigned long)param),
[opc] "i" (CPACF_KMAC)
: "cc", "memory", "0", "1");

return src_len - r3;
return src_len - s.odd;
}

/**
Expand All @@ -385,22 +394,24 @@ static inline int cpacf_kmac(unsigned long func, void *param,
static inline int cpacf_kmctr(unsigned long func, void *param, u8 *dest,
const u8 *src, long src_len, u8 *counter)
{
register unsigned long r0 asm("0") = (unsigned long) func;
register unsigned long r1 asm("1") = (unsigned long) param;
register unsigned long r2 asm("2") = (unsigned long) src;
register unsigned long r3 asm("3") = (unsigned long) src_len;
register unsigned long r4 asm("4") = (unsigned long) dest;
register unsigned long r6 asm("6") = (unsigned long) counter;
union register_pair d, s, c;

d.even = (unsigned long)dest;
s.even = (unsigned long)src;
s.odd = (unsigned long)src_len;
c.even = (unsigned long)counter;
asm volatile(
" lgr 0,%[fc]\n"
" lgr 1,%[pba]\n"
"0: .insn rrf,%[opc] << 16,%[dst],%[src],%[ctr],0\n"
" brc 1,0b\n" /* handle partial completion */
: [src] "+a" (r2), [len] "+d" (r3),
[dst] "+a" (r4), [ctr] "+a" (r6)
: [fc] "d" (r0), [pba] "a" (r1), [opc] "i" (CPACF_KMCTR)
: "cc", "memory");
: [src] "+&d" (s.pair), [dst] "+&d" (d.pair),
[ctr] "+&d" (c.pair)
: [fc] "d" (func), [pba] "d" ((unsigned long)param),
[opc] "i" (CPACF_KMCTR)
: "cc", "memory", "0", "1");

return src_len - r3;
return src_len - s.odd;
}

/**
Expand All @@ -417,20 +428,21 @@ static inline void cpacf_prno(unsigned long func, void *param,
u8 *dest, unsigned long dest_len,
const u8 *seed, unsigned long seed_len)
{
register unsigned long r0 asm("0") = (unsigned long) func;
register unsigned long r1 asm("1") = (unsigned long) param;
register unsigned long r2 asm("2") = (unsigned long) dest;
register unsigned long r3 asm("3") = (unsigned long) dest_len;
register unsigned long r4 asm("4") = (unsigned long) seed;
register unsigned long r5 asm("5") = (unsigned long) seed_len;
union register_pair d, s;

d.even = (unsigned long)dest;
d.odd = (unsigned long)dest_len;
s.even = (unsigned long)seed;
s.odd = (unsigned long)seed_len;
asm volatile (
" lgr 0,%[fc]\n"
" lgr 1,%[pba]\n"
"0: .insn rre,%[opc] << 16,%[dst],%[seed]\n"
" brc 1,0b\n" /* handle partial completion */
: [dst] "+a" (r2), [dlen] "+d" (r3)
: [fc] "d" (r0), [pba] "a" (r1),
[seed] "a" (r4), [slen] "d" (r5), [opc] "i" (CPACF_PRNO)
: "cc", "memory");
: [dst] "+&d" (d.pair)
: [fc] "d" (func), [pba] "d" ((unsigned long)param),
[seed] "d" (s.pair), [opc] "i" (CPACF_PRNO)
: "cc", "memory", "0", "1");
}

/**
Expand All @@ -443,19 +455,19 @@ static inline void cpacf_prno(unsigned long func, void *param,
static inline void cpacf_trng(u8 *ucbuf, unsigned long ucbuf_len,
u8 *cbuf, unsigned long cbuf_len)
{
register unsigned long r0 asm("0") = (unsigned long) CPACF_PRNO_TRNG;
register unsigned long r2 asm("2") = (unsigned long) ucbuf;
register unsigned long r3 asm("3") = (unsigned long) ucbuf_len;
register unsigned long r4 asm("4") = (unsigned long) cbuf;
register unsigned long r5 asm("5") = (unsigned long) cbuf_len;
union register_pair u, c;

u.even = (unsigned long)ucbuf;
u.odd = (unsigned long)ucbuf_len;
c.even = (unsigned long)cbuf;
c.odd = (unsigned long)cbuf_len;
asm volatile (
" lghi 0,%[fc]\n"
"0: .insn rre,%[opc] << 16,%[ucbuf],%[cbuf]\n"
" brc 1,0b\n" /* handle partial completion */
: [ucbuf] "+a" (r2), [ucbuflen] "+d" (r3),
[cbuf] "+a" (r4), [cbuflen] "+d" (r5)
: [fc] "d" (r0), [opc] "i" (CPACF_PRNO)
: "cc", "memory");
: [ucbuf] "+&d" (u.pair), [cbuf] "+&d" (c.pair)
: [fc] "K" (CPACF_PRNO_TRNG), [opc] "i" (CPACF_PRNO)
: "cc", "memory", "0");
}

/**
Expand All @@ -466,15 +478,15 @@ static inline void cpacf_trng(u8 *ucbuf, unsigned long ucbuf_len,
*/
static inline void cpacf_pcc(unsigned long func, void *param)
{
register unsigned long r0 asm("0") = (unsigned long) func;
register unsigned long r1 asm("1") = (unsigned long) param;

asm volatile(
" lgr 0,%[fc]\n"
" lgr 1,%[pba]\n"
"0: .insn rre,%[opc] << 16,0,0\n" /* PCC opcode */
" brc 1,0b\n" /* handle partial completion */
:
: [fc] "d" (r0), [pba] "a" (r1), [opc] "i" (CPACF_PCC)
: "cc", "memory");
: [fc] "d" (func), [pba] "d" ((unsigned long)param),
[opc] "i" (CPACF_PCC)
: "cc", "memory", "0", "1");
}

/**
Expand All @@ -487,14 +499,14 @@ static inline void cpacf_pcc(unsigned long func, void *param)
*/
static inline void cpacf_pckmo(long func, void *param)
{
register unsigned long r0 asm("0") = (unsigned long) func;
register unsigned long r1 asm("1") = (unsigned long) param;

asm volatile(
" lgr 0,%[fc]\n"
" lgr 1,%[pba]\n"
" .insn rre,%[opc] << 16,0,0\n" /* PCKMO opcode */
:
: [fc] "d" (r0), [pba] "a" (r1), [opc] "i" (CPACF_PCKMO)
: "cc", "memory");
: [fc] "d" (func), [pba] "d" ((unsigned long)param),
[opc] "i" (CPACF_PCKMO)
: "cc", "memory", "0", "1");
}

/**
Expand All @@ -512,21 +524,23 @@ static inline void cpacf_kma(unsigned long func, void *param, u8 *dest,
const u8 *src, unsigned long src_len,
const u8 *aad, unsigned long aad_len)
{
register unsigned long r0 asm("0") = (unsigned long) func;
register unsigned long r1 asm("1") = (unsigned long) param;
register unsigned long r2 asm("2") = (unsigned long) src;
register unsigned long r3 asm("3") = (unsigned long) src_len;
register unsigned long r4 asm("4") = (unsigned long) aad;
register unsigned long r5 asm("5") = (unsigned long) aad_len;
register unsigned long r6 asm("6") = (unsigned long) dest;
union register_pair d, s, a;

d.even = (unsigned long)dest;
s.even = (unsigned long)src;
s.odd = (unsigned long)src_len;
a.even = (unsigned long)aad;
a.odd = (unsigned long)aad_len;
asm volatile(
" lgr 0,%[fc]\n"
" lgr 1,%[pba]\n"
"0: .insn rrf,%[opc] << 16,%[dst],%[src],%[aad],0\n"
" brc 1,0b\n" /* handle partial completion */
: [dst] "+a" (r6), [src] "+a" (r2), [slen] "+d" (r3),
[aad] "+a" (r4), [alen] "+d" (r5)
: [fc] "d" (r0), [pba] "a" (r1), [opc] "i" (CPACF_KMA)
: "cc", "memory");
: [dst] "+&d" (d.pair), [src] "+&d" (s.pair),
[aad] "+&d" (a.pair)
: [fc] "d" (func), [pba] "d" ((unsigned long)param),
[opc] "i" (CPACF_KMA)
: "cc", "memory", "0", "1");
}

#endif /* _ASM_S390_CPACF_H */

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