--- Begin Message ---
Source: libi8x
Version: 0.0.5-1
Severity: important
User: [email protected]
Usertags: alignment
Hi!
I've been doing a full rebuild of the Debian archive, building all
source packages targeting armel and armhf using arm64 hardware. We are
planning in future to move all of our 32-bit armel/armhf builds to
using arm64 machines, so this rebuild is to identify packages that
might have problems with this configuration.
A feature of the arm64 kernel is that it does *not* support fixing up
code with broken alignment, so code that might have built and run OK
on our older armel/armhf build machines due to kernel fixups will now
fail.
When building your package, I've found a bus error (aka alignment
fault). The full log is online at
https://www.einval.com/debian/arm/rebuild-logs/armel/FAIL/libi8x_0.0.5-1_armel.log
for reference
I've done a quick bit of debugging to find the source of the
bug. Here's a gdb stacktrace and variable printout to demonstrate the
problem.
(sid-armel)steve@mjolnir:~/debian/build/libi8x/libi8x-0.0.5$ gdb
/home/steve/debian/build/libi8x/libi8x-0.0.5/tests/valid/.libs/test-corpus
tests/core
GNU gdb (Debian 8.2-1) 8.2
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License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
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Reading symbols from
/home/steve/debian/build/libi8x/libi8x-0.0.5/tests/valid/.libs/test-corpus...done.
[New LWP 5680]
Core was generated by
`/home/steve/debian/build/libi8x/libi8x-0.0.5/tests/valid/.libs/test-corpus'.
Program terminated with signal SIGBUS, Bus error.
#0 0xf7a9a0a8 in i8x_rb_read_int64_t (rb=rb@entry=0x1e57bc0,
result=0xff7f4af8, result@entry=0xff7f4af0)
at readbuf.c:158
158 I8X_RB_READ_FIXED_MULTI (64)
warning: File "/home/steve/debian/build/libi8x/libi8x-0.0.5/.gdbinit"
auto-loading has been declined by your `auto-load safe-path' set to
"$debugdir:$datadir/auto-load".
To enable execution of this file add
add-auto-load-safe-path
/home/steve/debian/build/libi8x/libi8x-0.0.5/.gdbinit
line to your configuration file "/home/steve/.gdbinit".
To completely disable this security protection add
set auto-load safe-path /
line to your configuration file "/home/steve/.gdbinit".
For more information about this security protection see the
"Auto-loading safe path" section in the GDB manual. E.g., run from the shell:
info "(gdb)Auto-loading safe path"
(gdb) bt
#0 0xf7a9a0a8 in i8x_rb_read_int64_t (rb=rb@entry=0x1e57bc0,
result=0xff7f4af8, result@entry=0xff7f4af0)
at readbuf.c:158
#1 0xf7a8d888 in i8x_code_read_operand (rb=0x1e57bc0, type=I8X_OPR_INT64,
operand=operand@entry=0x1e57988,
code=<optimized out>) at code.c:246
#2 0xf7a8e3a4 in i8x_code_unpack_bytecode (code=0x1e57908) at code.c:376
#3 i8x_code_init (code=0x1e57908) at code.c:757
#4 i8x_code_new (func=func@entry=0x1e57718, code=code@entry=0x1e57744) at
code.c:831
#5 0xf7a972d4 in i8x_bcf_init (func=0x1e57718) at function.c:143
#6 i8x_func_new_bytecode (note=<optimized out>, func=0xff7f4bf8) at
function.c:185
#7 0x0058ad1c in do_test (ctx=0x1dda150,
filename=0x1ddaec8
"corpus/i8c/0.0.3/32el/test_load_constant/test_output/0027-0001") at
valid/test-corpus.c:104
#8 0x0058b094 in ftw_callback (fpath=0x1ddaec8
"corpus/i8c/0.0.3/32el/test_load_constant/test_output/0027-0001",
sb=sb@entry=0xff7f6c50, typeflag=<optimized out>) at valid/test-corpus.c:142
#9 0xf7a023fc in process_entry (data=data@entry=0xff7f7290,
dir=dir@entry=0xff7f6d08,
name=name@entry=0x1e3f8fb "0027-0001", namlen=<optimized out>, d_type=8) at
ftw.c:464
#10 0xf7a0284c in ftw_dir (data=data@entry=0xff7f7290, st=0x8,
st@entry=0xff7f6d58,
old_dir=0xf7ae1968 <__stack_chk_guard>, old_dir@entry=0xff7f6e08) at
ftw.c:543
#11 0xf7a02584 in process_entry (data=data@entry=0xff7f7290,
dir=dir@entry=0xff7f6e08, name=<optimized out>,
name@entry=0x1e4adf3 "test_output", namlen=<optimized out>, d_type=4) at
ftw.c:461
#12 0xf7a0284c in ftw_dir (data=data@entry=0xff7f7290, st=0x4,
st@entry=0xff7f6e58,
old_dir=0xf7ae1968 <__stack_chk_guard>, old_dir@entry=0xff7f6f08) at
ftw.c:543
#13 0xf7a02584 in process_entry (data=data@entry=0xff7f7290,
dir=dir@entry=0xff7f6f08, name=<optimized out>,
name@entry=0x1df4333 "test_load_constant", namlen=<optimized out>,
d_type=4) at ftw.c:461
#14 0xf7a0284c in ftw_dir (data=data@entry=0xff7f7290, st=0x4,
st@entry=0xff7f6f58, old_dir=0xf7ae1968 <__stack_chk_guard>,
old_dir@entry=0xff7f7008) at ftw.c:543
#15 0xf7a02584 in process_entry (data=data@entry=0xff7f7290,
dir=dir@entry=0xff7f7008, name=<optimized out>,
name@entry=0x1debfe3 "32el", namlen=<optimized out>, d_type=4) at ftw.c:461
#16 0xf7a0284c in ftw_dir (data=data@entry=0xff7f7290, st=0x4,
st@entry=0xff7f7058,
old_dir=0xf7ae1968 <__stack_chk_guard>, old_dir@entry=0xff7f7108) at
ftw.c:543
#17 0xf7a02584 in process_entry (data=data@entry=0xff7f7290,
dir=dir@entry=0xff7f7108, name=<optimized out>,
name@entry=0x1de3f93 "0.0.3", namlen=<optimized out>, d_type=4) at ftw.c:461
#18 0xf7a0284c in ftw_dir (data=data@entry=0xff7f7290, st=0x4,
st@entry=0xff7f7158,
old_dir=0xf7ae1968 <__stack_chk_guard>, old_dir@entry=0xff7f7208) at
ftw.c:543
#19 0xf7a02584 in process_entry (data=data@entry=0xff7f7290,
dir=dir@entry=0xff7f7208, name=<optimized out>,
name@entry=0x1ddbf4b "i8c", namlen=<optimized out>, d_type=4) at ftw.c:461
#20 0xf7a0284c in ftw_dir (data=data@entry=0xff7f7290, st=0x4,
old_dir=0xf7ae1968 <__stack_chk_guard>,
old_dir@entry=0x0) at ftw.c:543
#21 0xf7a030b0 in ftw_startup (dir=<optimized out>, is_nftw=is_nftw@entry=0,
func=<optimized out>,
descriptors=<optimized out>, flags=flags@entry=0) at ftw.c:768
#22 0xf7a03248 in ftw64 (path=<optimized out>, func=<optimized out>,
descriptors=<optimized out>) at ftw.c:817
#23 0x0058b134 in i8x_validation_test (ctx=<optimized out>) at
valid/test-corpus.c:157
#24 0x0058b6e0 in i8x_validation_test_main () at libi8x-test.c:147
#25 0x0058aa24 in main (argc=<optimized out>, argv=<optimized out>) at
../libi8x-test/validation-test.h:32
(gdb) list
153 I8X_RB_READ_FIXED_MULTI_1 (int ## SIZE ## _t, bswap_ ## SIZE)
\
154 I8X_RB_READ_FIXED_MULTI_1 (uint ## SIZE ## _t, bswap_ ## SIZE)
155
156 I8X_RB_READ_FIXED_MULTI (16)
157 I8X_RB_READ_FIXED_MULTI (32)
158 I8X_RB_READ_FIXED_MULTI (64)
159
160 I8X_EXPORT i8x_err_e
161 i8x_rb_read_sleb128 (struct i8x_readbuf *rb, intptr_t *rp)
162 {
(gdb)
163 const char *ptr = rb->ptr;
164 intptr_t result = 0;
165 int shift = 0;
166
167 while (1)
168 {
169 uint8_t byte;
170 i8x_err_e err;
171
172 err = i8x_rb_read_uint8_t (rb, &byte);
(gdb) p tmp
$1 = <optimized out>
(gdb) p rb
$2 = (struct i8x_readbuf *) 0x1e57bc0
(gdb) p result
$3 = (int64_t *) 0xff7f4af8
(gdb) p *result
$4 = 42809880576
(gdb) p rb
$5 = (struct i8x_readbuf *) 0x1e57bc0
(gdb) p *rb
$6 = {_ob = {ops = 0xf7aaeec0 <i8x_readbuf_ops>, parent = 0x1e574b0, refcount =
{1, 0}, userdata = 0x0,
userdata_cleanup = 0x0, use_debug_allocator = true, is_moribund = false,
is_poisoned = false},
start = 0x1e0c141 "\017", limit = 0x1e0c14a "\001\002\004\006", ptr =
0x1e0c142 "",
byte_order = I8X_BYTE_ORDER_NATIVE}
Looks like rb->ptr is bogus, not aligned.
-- System Information:
Debian Release: 9.6
APT prefers stable-updates
APT policy: (500, 'stable-updates'), (500, 'stable-debug'), (500, 'stable')
Architecture: amd64 (x86_64)
Foreign Architectures: i386
Kernel: Linux 4.9.0-8-amd64 (SMP w/4 CPU cores)
Locale: LANG=en_GB.UTF-8, LC_CTYPE=en_GB.UTF-8 (charmap=UTF-8),
LANGUAGE=en_GB.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)
--- End Message ---
