WIP: random32: make siprand_state 4 longs instead of an array
I've met this strange error while making for allmodconfig:
scripts/kconfig/conf --syncconfig Kconfig
CALL scripts/checksyscalls.sh
CALL scripts/atomic/check-atomics.sh
DESCEND objtool
CC lib/random32.o
In file included from ./include/asm-generic/percpu.h:7,
from ./arch/x86/include/asm/percpu.h:390,
from ./arch/x86/include/asm/preempt.h:6,
from ./include/linux/preempt.h:78,
from ./include/linux/percpu.h:6,
from lib/random32.c:36:
lib/random32.c:323:30: error: structure variable 'net_rand_state' with 'latent_entropy' attribute has a non-integer field 'v'
323 | static DEFINE_PER_CPU(struct siprand_state, net_rand_state) __latent_entropy;
| ^~~~~~~~~~~~~
./include/linux/percpu-defs.h:95:38: note: in definition of macro 'DEFINE_PER_CPU_SECTION'
95 | __PCPU_ATTRS(sec) __weak __typeof__(type) name
| ^~~~
lib/random32.c:323:8: note: in expansion of macro 'DEFINE_PER_CPU'
323 | static DEFINE_PER_CPU(struct siprand_state, net_rand_state) __latent_entropy;
| ^~~~~~~~~~~~~~
make[2]: *** [lib/random32.o] Error 1
make[1]: *** [lib] Error 2
make: *** [__sub-make] Error 2
It goes away when the members of the struct are all individual
integers instead of an array of integers. We really don't care
since they're always used separately, let's change this.
diff --git a/lib/random32.c b/lib/random32.c
index 6fcb7a9..e09c7be 100644
--- a/lib/random32.c
+++ b/lib/random32.c
@@ -317,7 +317,10 @@ static void __init prandom_state_selftest(void)
*/
struct siprand_state {
- unsigned long v[4];
+ unsigned long v0;
+ unsigned long v1;
+ unsigned long v2;
+ unsigned long v3;
};
static DEFINE_PER_CPU(struct siprand_state, net_rand_state) __latent_entropy;
@@ -345,14 +348,14 @@ EXPORT_PER_CPU_SYMBOL(net_rand_noise);
*/
static inline u32 siprand_u32(struct siprand_state *s)
{
- unsigned long v0 = s->v[0], v1 = s->v[1], v2 = s->v[2], v3 = s->v[3];
+ unsigned long v0 = s->v0, v1 = s->v1, v2 = s->v2, v3 = s->v3;
unsigned long n = __this_cpu_read(net_rand_noise);
v3 ^= n;
PRND_SIPROUND(v0, v1, v2, v3);
PRND_SIPROUND(v0, v1, v2, v3);
v0 ^= n;
- s->v[0] = v0; s->v[1] = v1; s->v[2] = v2; s->v[3] = v3;
+ s->v0 = v0; s->v1 = v1; s->v2 = v2; s->v3 = v3;
return v1 + v3;
}
//EXPORT_SYMBOL(siprand_u32);
@@ -420,8 +423,8 @@ void prandom_seed(u32 entropy)
for_each_possible_cpu(i) {
struct siprand_state *state = per_cpu_ptr(&net_rand_state, i);
- unsigned long v0 = state->v[0], v1 = state->v[1];
- unsigned long v2 = state->v[2], v3 = state->v[3];
+ unsigned long v0 = state->v0, v1 = state->v1;
+ unsigned long v2 = state->v2, v3 = state->v3;
do {
v3 ^= entropy;
@@ -430,10 +433,10 @@ void prandom_seed(u32 entropy)
v0 ^= entropy;
} while (unlikely(!v0 || !v1 || !v2 || !v3));
- WRITE_ONCE(state->v[0], v0);
- WRITE_ONCE(state->v[1], v1);
- WRITE_ONCE(state->v[2], v2);
- WRITE_ONCE(state->v[3], v3);
+ WRITE_ONCE(state->v0, v0);
+ WRITE_ONCE(state->v1, v1);
+ WRITE_ONCE(state->v2, v2);
+ WRITE_ONCE(state->v3, v3);
}
}
EXPORT_SYMBOL(prandom_seed);
@@ -463,8 +466,8 @@ static int __init prandom_init_early(void)
v0 ^= i;
state = per_cpu_ptr(&net_rand_state, i);
- state->v[0] = v0; state->v[1] = v1;
- state->v[2] = v2; state->v[3] = v3;
+ state->v0 = v0; state->v1 = v1;
+ state->v2 = v2; state->v3 = v3;
}
return 0;
@@ -518,10 +521,10 @@ static void prandom_reseed(struct timer_list *unused)
* we write contains no zero words.
*/
state = per_cpu_ptr(&net_rand_state, i);
- WRITE_ONCE(state->v[0], v0 ? v0 : -1ul);
- WRITE_ONCE(state->v[1], v1 ? v1 : -1ul);
- WRITE_ONCE(state->v[2], v2 ? v2 : -1ul);
- WRITE_ONCE(state->v[3], v3 ? v3 : -1ul);
+ WRITE_ONCE(state->v0, v0 ? v0 : -1ul);
+ WRITE_ONCE(state->v1, v1 ? v1 : -1ul);
+ WRITE_ONCE(state->v2, v2 ? v2 : -1ul);
+ WRITE_ONCE(state->v3, v3 ? v3 : -1ul);
}
/* reseed every ~60 seconds, in [40 .. 80) interval with slack */
