adi_v5_jtag: avoid RAM exhaustion by limiting jtag queue size 48/4948/3
authorBohdan Tymkiv <bhdt@cypress.com>
Tue, 26 Feb 2019 09:45:40 +0000 (11:45 +0200)
committerAndreas Fritiofson <andreas.fritiofson@gmail.com>
Fri, 18 Oct 2019 08:20:49 +0000 (09:20 +0100)
Issue has been found when I tried to read 64 MiB QSPI flash bank.
Bank is memory mapped, default_flash_read() is used for 'flash read_bank'
command. OpenOCD consumed as much as 6.8 GiB of RAM during this
process. Investigation showed that this happens because JTAG queue
is not limited in any way. OpenOCD queues 16 millions of AP reads
allocating all corresponding data structures.

Most of this memory is allocated in:
cmd_queue_alloc (commands.c) - 4.2 GiB
dap_cmd_new (adi_v5_jtag.c) - 2.25GiB

This patch implements a pool of "struct dap_cmd" objects using
linked list. Objects are taken from a pool in "dap_cmd_new()" and
returned to the pool when they are not needed. Size of the pool
is limited to 64K of objects, JTAG queue is forcibly executed
when this limit is reached.

Checked with Valgrind and Clang analyzer - no new warnings.

Change-Id: I5aaaecce5ed71414f7965a2598f49742f6a6b2b5
Signed-off-by: Bohdan Tymkiv <bhdt@cypress.com>
Reviewed-on: http://openocd.zylin.com/4948
Tested-by: jenkins
Reviewed-by: Matthias Welwarsky <matthias@welwarsky.de>
src/target/adi_v5_jtag.c
src/target/arm_adi_v5.h
src/target/arm_dap.c

index a3867e1..df81134 100644 (file)
@@ -139,6 +139,13 @@ struct dap_cmd {
        uint8_t outvalue_buf[4];
 };
 
+#define MAX_DAP_COMMAND_NUM 65536
+
+struct dap_cmd_pool {
+       struct list_head lh;
+       struct dap_cmd cmd;
+} dap_cmd_pool;
+
 static void log_dap_cmd(const char *header, struct dap_cmd *el)
 {
 #ifdef DEBUG_WAIT
@@ -153,34 +160,75 @@ static void log_dap_cmd(const char *header, struct dap_cmd *el)
 #endif
 }
 
-static struct dap_cmd *dap_cmd_new(uint8_t instr,
+static int jtag_limit_queue_size(struct adiv5_dap *dap)
+{
+       if (dap->cmd_pool_size < MAX_DAP_COMMAND_NUM)
+               return ERROR_OK;
+
+       return dap_run(dap);
+}
+
+static struct dap_cmd *dap_cmd_new(struct adiv5_dap *dap, uint8_t instr,
                uint8_t reg_addr, uint8_t RnW,
                uint8_t *outvalue, uint8_t *invalue,
                uint32_t memaccess_tck)
 {
-       struct dap_cmd *cmd;
 
-       cmd = (struct dap_cmd *)calloc(1, sizeof(struct dap_cmd));
-       if (cmd != NULL) {
-               INIT_LIST_HEAD(&cmd->lh);
-               cmd->instr = instr;
-               cmd->reg_addr = reg_addr;
-               cmd->RnW = RnW;
-               if (outvalue != NULL)
-                       memcpy(cmd->outvalue_buf, outvalue, 4);
-               cmd->invalue = (invalue != NULL) ? invalue : cmd->invalue_buf;
-               cmd->memaccess_tck = memaccess_tck;
+       struct dap_cmd_pool *pool = NULL;
+
+       if (list_empty(&dap->cmd_pool)) {
+               pool = calloc(1, sizeof(struct dap_cmd_pool));
+               if (pool == NULL)
+                       return NULL;
+       } else {
+               pool = list_first_entry(&dap->cmd_pool, struct dap_cmd_pool, lh);
+               list_del(&pool->lh);
        }
 
+       INIT_LIST_HEAD(&pool->lh);
+       dap->cmd_pool_size++;
+
+       struct dap_cmd *cmd = &pool->cmd;
+       INIT_LIST_HEAD(&cmd->lh);
+       cmd->instr = instr;
+       cmd->reg_addr = reg_addr;
+       cmd->RnW = RnW;
+       if (outvalue != NULL)
+               memcpy(cmd->outvalue_buf, outvalue, 4);
+       cmd->invalue = (invalue != NULL) ? invalue : cmd->invalue_buf;
+       cmd->memaccess_tck = memaccess_tck;
+
        return cmd;
 }
 
-static void flush_journal(struct list_head *lh)
+static void dap_cmd_release(struct adiv5_dap *dap, struct dap_cmd *cmd)
+{
+       struct dap_cmd_pool *pool = container_of(cmd, struct dap_cmd_pool, cmd);
+       if (dap->cmd_pool_size > MAX_DAP_COMMAND_NUM)
+               free(pool);
+       else
+               list_add(&pool->lh, &dap->cmd_pool);
+
+       dap->cmd_pool_size--;
+}
+
+static void flush_journal(struct adiv5_dap *dap, struct list_head *lh)
 {
        struct dap_cmd *el, *tmp;
 
        list_for_each_entry_safe(el, tmp, lh, lh) {
                list_del(&el->lh);
+               dap_cmd_release(dap, el);
+       }
+}
+
+static void jtag_quit(struct adiv5_dap *dap)
+{
+       struct dap_cmd_pool *el, *tmp;
+       struct list_head *lh = &dap->cmd_pool;
+
+       list_for_each_entry_safe(el, tmp, lh, lh) {
+               list_del(&el->lh);
                free(el);
        }
 }
@@ -273,7 +321,7 @@ static int adi_jtag_dp_scan(struct adiv5_dap *dap,
        struct dap_cmd *cmd;
        int retval;
 
-       cmd = dap_cmd_new(instr, reg_addr, RnW, outvalue, invalue, memaccess_tck);
+       cmd = dap_cmd_new(dap, instr, reg_addr, RnW, outvalue, invalue, memaccess_tck);
        if (cmd != NULL)
                cmd->dp_select = dap->select;
        else
@@ -415,7 +463,7 @@ static int jtagdp_overrun_check(struct adiv5_dap *dap)
                                * To complete the READ, we just keep polling RDBUFF
                                * until the WAIT condition clears
                                */
-                               tmp = dap_cmd_new(JTAG_DP_DPACC,
+                               tmp = dap_cmd_new(dap, JTAG_DP_DPACC,
                                                DP_RDBUFF, DPAP_READ, NULL, NULL, 0);
                                if (tmp == NULL) {
                                        retval = ERROR_JTAG_DEVICE_ERROR;
@@ -459,7 +507,7 @@ static int jtagdp_overrun_check(struct adiv5_dap *dap)
                                }
 
                                /* we're done with this command, release it */
-                               free(tmp);
+                               dap_cmd_release(dap, tmp);
 
                                if (retval != ERROR_OK)
                                        goto done;
@@ -479,7 +527,7 @@ static int jtagdp_overrun_check(struct adiv5_dap *dap)
        }
 
        /* we're done with the journal, flush it */
-       flush_journal(&dap->cmd_journal);
+       flush_journal(dap, &dap->cmd_journal);
 
        /* check for overrun condition in the last batch of transactions */
        if (found_wait) {
@@ -494,7 +542,7 @@ static int jtagdp_overrun_check(struct adiv5_dap *dap)
                /* restore SELECT register first */
                if (!list_empty(&replay_list)) {
                        el = list_first_entry(&replay_list, struct dap_cmd, lh);
-                       tmp = dap_cmd_new(JTAG_DP_DPACC,
+                       tmp = dap_cmd_new(dap, JTAG_DP_DPACC,
                                          DP_SELECT, DPAP_WRITE, (uint8_t *)&el->dp_select, NULL, 0);
                        if (tmp == NULL) {
                                retval = ERROR_JTAG_DEVICE_ERROR;
@@ -545,8 +593,8 @@ static int jtagdp_overrun_check(struct adiv5_dap *dap)
        }
 
  done:
-       flush_journal(&replay_list);
-       flush_journal(&dap->cmd_journal);
+       flush_journal(dap, &replay_list);
+       flush_journal(dap, &dap->cmd_journal);
        return retval;
 }
 
@@ -595,7 +643,7 @@ static int jtagdp_transaction_endcheck(struct adiv5_dap *dap)
        }
 
  done:
-       flush_journal(&dap->cmd_journal);
+       flush_journal(dap, &dap->cmd_journal);
        return retval;
 }
 
@@ -618,7 +666,11 @@ static int jtag_check_reconnect(struct adiv5_dap *dap)
 static int jtag_dp_q_read(struct adiv5_dap *dap, unsigned reg,
                uint32_t *data)
 {
-       int retval =  adi_jtag_dp_scan_u32(dap, JTAG_DP_DPACC, reg,
+       int retval = jtag_limit_queue_size(dap);
+       if (retval != ERROR_OK)
+               return retval;
+
+       retval =  adi_jtag_dp_scan_u32(dap, JTAG_DP_DPACC, reg,
                        DPAP_READ, 0, dap->last_read, 0, NULL);
        dap->last_read = data;
        return retval;
@@ -627,7 +679,11 @@ static int jtag_dp_q_read(struct adiv5_dap *dap, unsigned reg,
 static int jtag_dp_q_write(struct adiv5_dap *dap, unsigned reg,
                uint32_t data)
 {
-       int retval =  adi_jtag_dp_scan_u32(dap, JTAG_DP_DPACC,
+       int retval = jtag_limit_queue_size(dap);
+       if (retval != ERROR_OK)
+               return retval;
+
+       retval =  adi_jtag_dp_scan_u32(dap, JTAG_DP_DPACC,
                        reg, DPAP_WRITE, data, dap->last_read, 0, NULL);
        dap->last_read = NULL;
        return retval;
@@ -650,7 +706,11 @@ static int jtag_ap_q_bankselect(struct adiv5_ap *ap, unsigned reg)
 static int jtag_ap_q_read(struct adiv5_ap *ap, unsigned reg,
                uint32_t *data)
 {
-       int retval = jtag_check_reconnect(ap->dap);
+       int retval = jtag_limit_queue_size(ap->dap);
+       if (retval != ERROR_OK)
+               return retval;
+
+       retval = jtag_check_reconnect(ap->dap);
        if (retval != ERROR_OK)
                return retval;
 
@@ -668,7 +728,11 @@ static int jtag_ap_q_read(struct adiv5_ap *ap, unsigned reg,
 static int jtag_ap_q_write(struct adiv5_ap *ap, unsigned reg,
                uint32_t data)
 {
-       int retval = jtag_check_reconnect(ap->dap);
+       int retval = jtag_limit_queue_size(ap->dap);
+       if (retval != ERROR_OK)
+               return retval;
+
+       retval = jtag_check_reconnect(ap->dap);
        if (retval != ERROR_OK)
                return retval;
 
@@ -725,4 +789,5 @@ const struct dap_ops jtag_dp_ops = {
        .queue_ap_abort      = jtag_ap_q_abort,
        .run                 = jtag_dp_run,
        .sync                = jtag_dp_sync,
+       .quit                = jtag_quit,
 };
index 6e2d8a1..ee04d41 100644 (file)
@@ -234,6 +234,12 @@ struct adiv5_dap {
        /* dap transaction list for WAIT support */
        struct list_head cmd_journal;
 
+       /* pool for dap_cmd objects */
+       struct list_head cmd_pool;
+
+       /* number of dap_cmd objects in the pool */
+       size_t cmd_pool_size;
+
        struct jtag_tap *tap;
        /* Control config */
        uint32_t dp_ctrl_stat;
index fbcfe0d..0f29578 100644 (file)
@@ -59,6 +59,7 @@ static void dap_instance_init(struct adiv5_dap *dap)
                dap->ap[i].csw_default = CSW_AHB_DEFAULT;
        }
        INIT_LIST_HEAD(&dap->cmd_journal);
+       INIT_LIST_HEAD(&dap->cmd_pool);
 }
 
 const char *adiv5_dap_name(struct adiv5_dap *self)