Here's the 95% CPU loop.

(gdb) fin
Run till exit from #0  strfind (haystack=<value optimized out>, hslen=4096, needle=0x408844 "\r\n\r\n", ndlen=4) at uhttpd-utils.c:83
0x00402428 in uh_mainloop (conf=0x7fb38f04, serv_fds={fds_bits = {8, 0 <repeats 31 times>}}, max_fd=4) at uhttpd.c:390
390	uhttpd.c: No such file or directory.
	in uhttpd.c
Value returned is $2 = 0x0
(gdb) s
402	in uhttpd.c
(gdb) 
uh_tcp_recv (cl=0x41e008, buf=0x41a5a0 "", len=0) at uhttpd-utils.c:171
171	uhttpd-utils.c: No such file or directory.
	in uhttpd-utils.c
(gdb) 
166	in uhttpd-utils.c
(gdb) 
171	in uhttpd-utils.c
(gdb) 
181	in uhttpd-utils.c
(gdb) 
uh_mainloop (conf=0x7fb38f04, serv_fds={fds_bits = {8, 0 <repeats 31 times>}}, max_fd=4) at uhttpd.c:375
375	uhttpd.c: No such file or directory.
	in uhttpd.c
(gdb) 
405	in uhttpd.c
(gdb) 
378	in uhttpd.c
(gdb) 
382	in uhttpd.c
(gdb) 
378	in uhttpd.c
(gdb) 
382	in uhttpd.c
(gdb) 
378	in uhttpd.c
(gdb) 
381	in uhttpd.c
(gdb) 
385	in uhttpd.c
(gdb) 
388	in uhttpd.c
(gdb) 
uh_tcp_peek (cl=0x41e008, buf=0x41a5a0 "", len=4095) at uhttpd-utils.c:152
152	uhttpd-utils.c: No such file or directory.
	in uhttpd-utils.c
(gdb) 
153	in uhttpd-utils.c
(gdb) 
uh_tcp_recv (cl=0x41e008, buf=0x41a5a0 "", len=4095) at uhttpd-utils.c:171
171	in uhttpd-utils.c
(gdb) 
166	in uhttpd-utils.c
(gdb) 
171	in uhttpd-utils.c
(gdb) 
181	in uhttpd-utils.c
(gdb) 
184	in uhttpd-utils.c
(gdb) 
188	in uhttpd-utils.c
(gdb) 
190	in uhttpd-utils.c
(gdb) 
195	in uhttpd-utils.c
(gdb) 
uh_tcp_peek (cl=0x41e008, buf=0x41a5a0 "", len=<value optimized out>) at uhttpd-utils.c:156
156	in uhttpd-utils.c
(gdb) 
163	in uhttpd-utils.c
(gdb) 
uh_mainloop (conf=0x7fb38f04, serv_fds={fds_bits = {8, 0 <repeats 31 times>}}, max_fd=4) at uhttpd.c:390
390	uhttpd.c: No such file or directory.
	in uhttpd.c
(gdb) 
strfind (haystack=0x41a5a0 "", hslen=4096, needle=0x408844 "\r\n\r\n", ndlen=4) at uhttpd-utils.c:87
87	uhttpd-utils.c: No such file or directory.
	in uhttpd-utils.c
(gdb)