By comparing the address of the initial 'name' field instead of the
addresses of the objects themselves, a small amount of type safety is
added back, vs just casting to void.
In the event that some other kind of object is passed in as 't',
which happens to have a 'name' field of the right type, the construct
would be (undesirably) accepted but it would almost certainly evaluate
to false at runtime.
Prior to this commit, cache flushing for ARM native code was done only in
the assembler code asm_thumb_end_pass()/asm_arm_end_pass(), at the last
pass of the assembler. But this misses flushing the cache when loading
native code from an .mpy file, ie in persistentcode.c.
The change here makes sure the cache is always flushed/cleaned/invalidated
when assigning native code on ARM architectures.
This problem was found running tests/micropython/import_mpy_native_gc.py on
the mimxrt port.
Signed-off-by: Damien George <damien@micropython.org>
asan considers that memcmp(p, q, N) is permitted to access N bytes at each
of p and q, even for values of p and q that have a difference earlier.
Accessing additional values is frequently done in practice, reading 4 or
more bytes from each input at a time for efficiency, so when completing
"non_exist<TAB>" in the repl, this causes a diagnostic:
==16938==ERROR: AddressSanitizer: global-buffer-overflow on
address 0x555555cd8dc8 at pc 0x7ffff726457b bp 0x7fffffffda20 sp 0x7fff
READ of size 9 at 0x555555cd8dc8 thread T0
#0 0x7ffff726457a (/usr/lib/x86_64-linux-gnu/libasan.so.5+0xb857a)
#1 0x555555b0e82a in mp_repl_autocomplete ../../py/repl.c:301
#2 0x555555c89585 in readline_process_char ../../lib/mp-readline/re
#3 0x555555c8ac6e in readline ../../lib/mp-readline/readline.c:513
#4 0x555555b8dcbd in do_repl /home/jepler/src/micropython/ports/uni
#5 0x555555b90859 in main_ /home/jepler/src/micropython/ports/unix/
#6 0x555555b90a3a in main /home/jepler/src/micropython/ports/unix/m
#7 0x7ffff619a09a in __libc_start_main ../csu/libc-start.c:308
#8 0x55555595fd69 in _start (/home/jepler/src/micropython/ports/uni
0x555555cd8dc8 is located 0 bytes to the right of global variable
'import_str' defined in '../../py/repl.c:285:23' (0x555555cd8dc0) of
size 8
'import_str' is ascii string 'import '
Signed-off-by: Jeff Epler <jepler@gmail.com>
