Commit 80e3dc47 authored by Nick Mathewson's avatar Nick Mathewson 🤹
Browse files

Use more memory poisoning and better asserts around ewma code 

Attempt to diagnose 32464; fixes 33290.
parent 5298113d

changes/ticket33290

0 → 100644
+4 −0
Original line number Diff line number Diff line 
  o Minor features (diagnostic):

    - Improve assertions and add some memory-poisoning code to try to track

      down possible causes of a rare crash (32564) in the EWMA code.

      Closes ticket 33290.

src/core/or/circuitmux.c

+6 −2
Original line number Diff line number Diff line
@@ -79,6 +79,8 @@ 
#include "core/or/destroy_cell_queue_st.h"

#include "core/or/or_circuit_st.h"



#include "lib/crypt_ops/crypto_util.h"



/*

 * Private typedefs for circuitmux.c

 */
@@ -973,7 +975,10 @@ circuitmux_detach_circuit,(circuitmux_t *cmux, circuit_t *circ)) 
    /* Now remove it from the map */

    HT_REMOVE(chanid_circid_muxinfo_map, cmux->chanid_circid_map, hashent);



    /* Free the hash entry */

    /* Wipe and free the hash entry */

    // This isn't sensitive, but we want to be sure to know if we're accessing

    // this accidentally.

    memwipe(hashent, 0xef, sizeof(hashent));

    tor_free(hashent);

  }

}
@@ -1334,4 +1339,3 @@ circuitmux_compare_muxes, (circuitmux_t *cmux_1, circuitmux_t *cmux_2)) 
    return 0;

  }

}

src/core/or/circuitmux_ewma.c

+8 −3
Original line number Diff line number Diff line
@@ -147,7 +147,9 @@ TO_EWMA_POL_DATA(circuitmux_policy_data_t *pol) 
{

  if (!pol) return NULL;

  else {

    tor_assert(pol->magic == EWMA_POL_DATA_MAGIC);

    tor_assertf(pol->magic == EWMA_POL_DATA_MAGIC,

                "Mismatch: %"PRIu32" != %"PRIu32,

                pol->magic, EWMA_POL_DATA_MAGIC);

    return DOWNCAST(ewma_policy_data_t, pol);

  }

}
@@ -162,7 +164,9 @@ TO_EWMA_POL_CIRC_DATA(circuitmux_policy_circ_data_t *pol) 
{

  if (!pol) return NULL;

  else {

    tor_assert(pol->magic == EWMA_POL_CIRC_DATA_MAGIC);

    tor_assertf(pol->magic == EWMA_POL_CIRC_DATA_MAGIC,

                "Mismatch: %"PRIu32" != %"PRIu32,

                pol->magic, EWMA_POL_CIRC_DATA_MAGIC);

    return DOWNCAST(ewma_policy_circ_data_t, pol);

  }

}
@@ -295,6 +299,7 @@ ewma_free_cmux_data(circuitmux_t *cmux, 
  pol = TO_EWMA_POL_DATA(pol_data);



  smartlist_free(pol->active_circuit_pqueue);

  pol->base_.magic = 0xDEAD901C;

  tor_free(pol);

}
@@ -361,7 +366,7 @@ ewma_free_circ_data(circuitmux_t *cmux, 
  if (!pol_circ_data) return;



  cdata = TO_EWMA_POL_CIRC_DATA(pol_circ_data);



  cdata->base_.magic = 0xDEADC14C;

  tor_free(cdata);

}