[lwip-users] Pagefault while calling lwip_gethostbyname

[Karthik Vadambacheri Manian]

Hi All,

I am trying to invoke lwip_gethostbyname(const char *name) but
actually it results in a pagefault. On further investigation I found
that lwip_gethostbyname(const char *name) inturn calls
netconn_gethostbyname(const char *name, struct ip_addr *addr). Here a
variable by name 'msg' of struct dns_api_msg is defined and
initialized. Then the function do_gethostbyname(void *arg) is set as
the tcpip callback function with the previously declared variable msg
as the argument. During tcpip callback, this do_gethostbyname function
is called and inside the function it tries to dereference the members
of msg and it results in the pagefault. Also I tried to print the
address of the variable msg inside netconn_gethostbyname() and in
do_gethostbyname(), both of them result in the same address. But if we
try to dereference the members of msg in do_gethostbyname() I get a
page fault. Am I missing something here. Please let me know.

Thanks for your time,
karthik