[PATCH] eal: zero out new added memory

[chengtcli@qq.com]

From: lic121 <lic121@chinatelecom.cn>

When RTE_MALLOC_DEBUG not configured, rte_zmalloc_socket() doens't
zero oute allocaed memory. Because memory are zeroed out when free
in malloc_elem_free(). But seems the initial allocated memory is
not zeroed out as expected.

This patch zero out initial allocated memory in
malloc_heap_add_memory().

With dpdk 20.11.5, "QLogic Corp. FastLinQ QL41000" probe triggers
this problem.
```
  Stack trace of thread 412780:
  #0  0x0000000000e5fb99 ecore_int_igu_read_cam (dpdk-testpmd)
  #1  0x0000000000e4df54 ecore_get_hw_info (dpdk-testpmd)
  #2  0x0000000000e504aa ecore_hw_prepare (dpdk-testpmd)
  #3  0x0000000000e8a7ca qed_probe (dpdk-testpmd)
  #4  0x0000000000e83c59 qede_common_dev_init (dpdk-testpmd)
  #5  0x0000000000e84c8e qede_eth_dev_init (dpdk-testpmd)
  #6  0x00000000009dd5a7 rte_pci_probe_one_driver (dpdk-testpmd)
  #7  0x00000000009734e3 rte_bus_probe (dpdk-testpmd)
  #8  0x00000000009933bd rte_eal_init (dpdk-testpmd)
  #9  0x000000000041768f main (dpdk-testpmd)
  #10 0x00007f41a7001b17 __libc_start_main (libc.so.6)
  #11 0x000000000067e34a _start (dpdk-testpmd)
```

Signed-off-by: lic121 <lic121@chinatelecom.cn>
---
 lib/librte_eal/common/malloc_heap.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/lib/librte_eal/common/malloc_heap.c b/lib/librte_eal/common/malloc_heap.c
index f4e20ea..1607401 100644
--- a/lib/librte_eal/common/malloc_heap.c
+++ b/lib/librte_eal/common/malloc_heap.c
@@ -96,11 +96,19 @@
 		void *start, size_t len)
 {
 	struct malloc_elem *elem = start;
+	void *ptr;
+	size_t data_len
+
 
 	malloc_elem_init(elem, heap, msl, len, elem, len);
 
 	malloc_elem_insert(elem);
 
+	/* Zero out new added memory. */
+	*ptr = RTE_PTR_ADD(elem, MALLOC_ELEM_HEADER_LEN);
+	data_len = elem->size - MALLOC_ELEM_OVERHEAD;
+	memset(ptr, 0, data_len);
+
 	elem = malloc_elem_join_adjacent_free(elem);
 
 	malloc_elem_free_list_insert(elem);
-- 
1.8.3.1