[BUG] tools/mkimage is broken on macos arm64
Sergey V. Lobanov
sergey at lobanov.in
Wed Dec 1 00:06:14 CET 2021
I’ve found that u-boot mkimage doesn’t work on macos arm64 due to ASLR mechanism.
Jessica, do you have any idea how to rewrite INIT_SECTION define to make it compatible with ASLR mechanism?
(It is related to commit https://github.com/u-boot/u-boot/commit/3b142045e8a7f0ab17b6099e9226296af45967d0 )
LLDB uses undocumented way to disable ASLR that is why mkimage works under LLDB (https://stackoverflow.com/questions/23897963/documented-way-to-disable-aslr-on-os-x )
On modern MacOS systems it is the only way to disable ASLR (use lldb or just use the code from LLDB to disable ASBR)
sergey at Sergeys-MacBook-Air tools % lldb ./mkimage
(lldb) target create "./mkimage"
Current executable set to '/Volumes/OpenWrt/u-boot/tools/mkimage' (arm64).
(lldb) settings set target.disable-aslr false
(lldb) r -f a b
Process 46167 launched: '/Volumes/OpenWrt/u-boot/tools/mkimage' (arm64)
BEFORE INIT
AFTER INIT
1
3
0x100045e48
mkimage was compiled with optimization - stepping may behave oddly; variables may not be available.
Process 46167 stopped
* thread #1, queue = 'com.apple.main-thread', stop reason = EXC_BAD_ACCESS (code=1, address=0x100045e48)
frame #0: 0x0000000102a9cecc mkimage`imagetool_get_type(type=8) at imagetool.c:27:27 [opt]
24
25 for (curr = start; curr != end; curr++) {
26 fprintf(stderr, "%p\n", curr);
-> 27 fprintf(stderr, "%p\n", *curr);
28
29 // sleep(100000);
30 if ((*curr)->check_image_type) {
Target 0: (mkimage) stopped.
(lldb) exit
Quitting LLDB will kill one or more processes. Do you really want to proceed: [Y/n] y
******With ASLR it generates segfault
sergey at Sergeys-MacBook-Air tools % lldb ./mkimage
(lldb) target create "./mkimage"
Current executable set to '/Volumes/OpenWrt/u-boot/tools/mkimage' (arm64).
(lldb) r -f a b
Process 46172 launched: '/Volumes/OpenWrt/u-boot/tools/mkimage' (arm64)
BEFORE INIT
AFTER INIT
1
3
0x100045e48
0x100044560
0x100045e50
0x100044780
0x100045e58
0x1000447d8
sh: dtc: command not found
/Volumes/OpenWrt/u-boot/tools/mkimage: Can't open b.tmp: No such file or directory
Process 46172 exited with status = 255 (0x000000ff)
> On 30 Nov 2021, at 18:02, Sergey V. Lobanov <sergey at lobanov.in> wrote:
>
> I added some printf debugs to imagetool.c and recompiled with debug symbols:
>
> struct image_type_params *imagetool_get_type(int type)
> {
> struct image_type_params **curr;
> fprintf(stderr, "BEFORE INIT\n");
> INIT_SECTION(image_type);
> + fprintf(stderr, "AFTER INIT\n");
>
> + fprintf(stderr, "1\n");
> struct image_type_params **start = __start_image_type;
> struct image_type_params **end = __stop_image_type;
> + fprintf(stderr, "3\n");
>
> for (curr = start; curr != end; curr++) {
> + fprintf(stderr, "%p\n", curr);
>
> if ((*curr)->check_image_type) {
> if (!(*curr)->check_image_type(type))
> return *curr;
> }
> }
> return NULL;
> }
>
> % ./mkimage -f aaa bbb
> BEFORE INIT
> AFTER INIT
> 1
> 3
> 0x100041e48
> zsh: segmentation fault (core dumped) ./mkimage -f aaa bbb
>
> % lldb ./mkimage -c /cores/core.95889
> (lldb) target create "./mkimage" --core "/cores/core.95889”
> ...
>
> (lldb) bt all
> mkimage was compiled with optimization - stepping may behave oddly; variables may not be available.
> * thread #1, stop reason = signal SIGSTOP
> * frame #0: 0x00000001048ec168 mkimage`imagetool_get_type(type=<unavailable>) at imagetool.c:27:8 [opt]
> frame #1: 0x000000010490c008 mkimage`main(argc=<unavailable>, argv=<unavailable>) at mkimage.c:357:12 [opt]
> frame #2: 0x000000018c2f5430 libdyld.dylib`start + 4
> (lldb) f 0
> frame #0: 0x00000001048ec168 mkimage`imagetool_get_type(type=<unavailable>) at imagetool.c:27:8 [opt]
> 24 for (curr = start; curr != end; curr++) {
> 25 fprintf(stderr, "%p\n", curr);
> 26
> -> 27 if ((*curr)->check_image_type) {
> 28 if (!(*curr)->check_image_type(type))
> 29 return *curr;
>
>
> And the most interesting thing, mkimage doesn’t segfault if it is launched under lldb:
>
> % lldb ./mkimage
> (lldb) target create "./mkimage"
> Current executable set to '/Volumes/u-boot/tools/mkimage' (arm64).
> (lldb) r -f aaa bbb
> Process 95950 launched: '/Volumes/u-boot/tools/mkimage' (arm64)
> BEFORE INIT
> AFTER INIT
> 1
> 3
> 0x100041e48
> 0x100041e50
> 0x100041e58
> sh: dtc: command not found
> /Volumes/u-boot/tools/mkimage: Can't open bbb.tmp: No such file or directory
>
>
>
>
>> On 30 Nov 2021, at 14:49, Sergey V. Lobanov <sergey at lobanov.in> wrote:
>>
>> Hello,
>>
>> I have observed that u-boot mkimage is broken on macos arm64, it generates segfault every time.
>>
>> Reproducing:
>>
>> My MacOS environment:
>> % sw_vers
>> ProductName: macOS
>> ProductVersion: 11.6
>> BuildVersion: 20G165
>>
>> % uname -s -r -m
>> Darwin 20.6.0 arm64
>>
>> 1. Build on macos arm64
>> % export CPATH=/opt/homebrew/opt/openssl at 1.1/include
>> % export LIBRARY_PATH=/opt/homebrew/opt/openssl at 1.1/lib
>> % make tools
>>
>> 2. Versions
>> % git log | head -n 1
>> commit ade37460a944aed36ae6ee634c4d4a9a22690461
>>
>> % ./mkimage -V
>> mkimage version 2022.01-rc3
>>
>> 3. Run
>> % ./mkimage -f aaa bbb
>> zsh: segmentation fault ./mkimage -f aaa bbb
>>
>> (Diagnostics related to the segfault attached)
>>
>> The same story for Mac homebrew’s version:
>>
>> % mkimage -V
>> mkimage version 2021.10
>> % mkimage -f aaa bbb
>> zsh: segmentation fault mkimage -f aaa bbb
>>
>>
>> If do the same on normal Linux host, everything is ok (no segfault):
>>
>> $ uname -s -r -m
>> Linux 4.19.0-18-amd64 x86_64
>>
>> $ ./mkimage -V
>> mkimage version 2022.01-rc3
>>
>> $ ./mkimage -f aaa bbb
>> FATAL ERROR: Couldn't open "aaa": No such file or directory
>> ./mkimage: Can't open bbb.tmp: No such file or directory
>>
>>
>> <mkimage_2021-11-30-132645_Sergeys-MacBook-Air.crash.txt>
>
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