runtime: constrain ticks_per_slot in block harness

- Fixes bug where slots_per_year parameter differs between bank
  and genesis config (U.B. in the SVM)
- Fixes bug where slots_per_year is taken from epoch context even
  though it can be fully derived from genesis config
- Constrains ticks_per_slot (a hardcoded genesis parameter) to
  reasonable values, which would otherwise cause invalid floating
  points (denormals, infinite values) in epoch bounaries

Author: riptl

src/flamenco/rewards/fd_rewards.c

@@ -1,4 +1,5 @@
 #include "fd_rewards.h"
+#include <cfloat>
 #include <math.h>
 
 #include "../runtime/fd_acc_mgr.h"
@@ -17,9 +18,7 @@
 /* https://github.com/anza-xyz/agave/blob/7117ed9653ce19e8b2dea108eff1f3eb6a3378a7/sdk/src/inflation.rs#L85 */
 static double
 total( fd_inflation_t const * inflation, double year ) {
-  if ( FD_UNLIKELY( year == 0.0 ) ) {
-    FD_LOG_ERR(( "inflation year 0" ));
-  }
+  if( FD_UNLIKELY( year < DBL_EPSILON ) ) FD_LOG_ERR(( "invalid inflation year parameter (corrupt genesis config?)" ));
   double tapered = inflation->initial * pow( (1.0 - inflation->taper), year );
   return (tapered > inflation->terminal) ? tapered : inflation->terminal;
 }
@@ -88,6 +87,11 @@ static double
 slot_in_year_for_inflation( fd_bank_t const * bank ) {
   fd_epoch_schedule_t const * epoch_schedule = fd_bank_epoch_schedule_query( bank );
   ulong num_slots = get_inflation_num_slots( bank, epoch_schedule, fd_bank_slot_get( bank ) );
+  FD_LOG_DEBUG(( "slot_in_year_for_inflation:"
+                 " num_slots=%lu"
+                 " slots_per_year=%g",
+                 num_slots,
+                 fd_bank_slots_per_year_get( bank ) ));
   return (double)num_slots / (double)fd_bank_slots_per_year_get( bank );
 }
 
@@ -441,7 +445,17 @@ calculate_previous_epoch_inflation_rewards( fd_bank_t const *
   rewards->foundation_rate              = foundation( fd_bank_inflation_query( bank ), slot_in_year );
   rewards->prev_epoch_duration_in_years = epoch_duration_in_years( bank, prev_epoch );
   rewards->validator_rewards            = (ulong)(rewards->validator_rate * (double)prev_epoch_capitalization * rewards->prev_epoch_duration_in_years);
-  FD_LOG_DEBUG(( "Rewards %lu, Rate %.16f, Duration %.18f Capitalization %lu Slot in year %.16f", rewards->validator_rewards, rewards->validator_rate, rewards->prev_epoch_duration_in_years, prev_epoch_capitalization, slot_in_year ));
+  FD_LOG_DEBUG(( "calculate_previous_epoch_inflation_rewards:"
+                 " slot_in_year=%g"
+                 " valdiator_rewards=%lu"
+                 " validator_rate=%g"
+                 " prev_epoch_duration_in_years=%g"
+                 " prev_epoch_capitalization=%lu",
+                 slot_in_year,
+                 rewards->validator_rewards,
+                 rewards->validator_rate,
+                 rewards->prev_epoch_duration_in_years,
+                 prev_epoch_capitalization ));
 }
 
 /* https://github.com/anza-xyz/agave/blob/cbc8320d35358da14d79ebcada4dfb6756ffac79/programs/stake/src/lib.rs#L29 */
@@ -998,6 +1012,11 @@ fd_distribute_partitioned_epoch_rewards( fd_bank_t *               bank,
   ulong distribution_starting_block_height = epoch_rewards->starting_block_height;
   ulong distribution_end_exclusive         = fd_epoch_rewards_get_exclusive_ending_block_height( epoch_rewards );
 
+  if( block_height < distribution_starting_block_height ) {
+    fd_bank_epoch_rewards_end_locking_query( bank );
+    return;
+  }
+
   fd_epoch_schedule_t const * epoch_schedule = fd_bank_epoch_schedule_query( bank );
   ulong                       epoch          = fd_bank_epoch_get( bank );
 

src/flamenco/runtime/tests/fd_block_harness.c

@@ -238,6 +238,13 @@ fd_solfuzz_pb_block_ctx_destroy( fd_solfuzz_runner_t * runner ) {
   fd_progcache_clear( runner->progcache_admin );
 }
 
+static double
+years_as_slots( double years,
+                ulong  tick_duration_ns,
+                ulong  ticks_per_slot ) {
+  return years * SECONDS_PER_YEAR * (1e9 / (double)tick_duration_ns) / (double)ticks_per_slot;
+}
+
 /* Sets up block execution context from an input test case to execute
    against the runtime.  Returns block_info on success and NULL on
    failure. */
@@ -296,7 +303,15 @@ fd_solfuzz_pb_block_ctx_create( fd_solfuzz_runner_t *                runner,
 
   fd_bank_genesis_creation_time_set( bank, test_ctx->epoch_ctx.genesis_creation_time );
 
-  fd_bank_slots_per_year_set( bank, test_ctx->epoch_ctx.slots_per_year );
+  double slots_per_year = years_as_slots( 1.0, 6250000, test_ctx->epoch_ctx.ticks_per_slot );
+  if( FD_UNLIKELY( test_ctx->epoch_ctx.ticks_per_slot <    1 ||
+                   test_ctx->epoch_ctx.ticks_per_slot > 1000 ||
+                   slots_per_year<1000. ||
+                   slots_per_year>10e9 ) ) {
+    FD_LOG_ERR(( "invalid ticks_per_slot value: %lu", test_ctx->epoch_ctx.ticks_per_slot ));
+  }
+
+  fd_bank_slots_per_year_set( bank, slots_per_year );
 
   fd_bank_parent_signature_cnt_set( bank, test_ctx->slot_ctx.parent_signature_count );