WeChat fail with SIGSEGV box64 cfree on RISCV

[zqb-all]

When trying WeChat, the following log repeatedly appears in the logs.

[BOX64] 44917|SIGSEGV @(nil) (???((nil))) (x64pc=0x300000b3/"box64/cfree + 0x13", rsp=0x3ff7bfe958), for accessing 0x3800000000 (code=2)
RAX:0x0000003800218070 RCX:0x0000003800218070 RDX:0x0000000000000008 RBX:0x0000003800218038 
RSP:0x0000003ff7bfe958 RBP:0x0000000000000000 RSI:0x0000003800218030 RDI:0x0000003800218030 
 R8:0x0000003800218080  R9:0x00000000000000a0 R10:0x000000000000b000 R11:0x000000010ca097c0 
R12:0x0000003800210288 R13:0x0000000000000002 R14:0x0000003800218080 R15:0x0000003800210280 ES:0x002b CS:0x0033 SS:0x002b DS:0x002b FS:0x0000 GS:0x0000 FSBASE=0x359e36d0 GSBASE=(nil)

The login process often gets stuck for a long time and may ultimately fail or succeed.

Here is the complete log:
box64_wechat_20260203.txt

I noticed that my issue is similar to issue 2429, and the error log contains "cfree," which also appears in issue 2911. I'm not sure if it's related.

Thanks in advance for any suggestions.

[ptitSeb]

You probably need a profile for the app with maaloc hack.
To try, create (or edit if present): ~/.box64rc
and add:

[WeChatAppEx]
BOX64_MALLOC_HACK=2

If this work, I can add it to the system-wide version distributed with box64, so it work automaticaly for everyone.

[zqb-all]

with BOX64_MALLOC_HACK=2 , login process still gets stuck.

no cfree error now, last log is

[0204/091719.862557:ERROR:ptracer.cc(47)] Unexpected registers size 264 != 512
[0204/091719.863344:WARNING:process_reader_linux.cc(400)] Couldn't initialize main thread.
[0204/091719.863688:WARNING:exception_snapshot_linux.cc(406)] thread ID 58581 not found in process
[0204/091719.866845:ERROR:process_snapshot_linux.cc(129)] thread not found 58581
[BOX64] 58581|Double SIGSEGV (code=1, pc=(nil), x64pc=0x30232e73, addr=0x120000c670, prot=00)!
[BOX64] Sigfault/Segbus while quitting, exiting silently

full log:
box64_wechat_malloc_hack_2.txt

[zqb-all]

Sorry, I forgot to enable -D RV64=1 during compilation.

Now, after compiling with -D RV64=1 -D CMAKE_BUILD_TYPE=RelWithDebInfo, it no longer gets stuck at the login screen for long periods.
Both with and without BOX64_MALLOC_HACK=2, I can enter the main WeChat interface. Although operations like scrolling up and down with the mouse wheel are somewhat laggy, basic message sending and receiving tasks can be completed.

According to the logs, there are different SIGSEGV whether BOX64_MALLOC_HACK=2 is set or not.

Without BOX64_MALLOC_HACK=2 :

[BOX64] 75282|SIGSEGV @0x3ff7eb70d4 (__libc_free(/usr/lib/riscv64-linux-gnu/libc.so.6)) (x64pc=0x300000a0/"box64/cfree", rsp=0x3ff7bfe980, stack=0x3ff7400000:0x3ff7c00000 own=(nil) fp=(nil)), for accessing 0x3800000000 (code=2/prot=0), db=(nil)((nil):(nil)/(nil):(nil)/???:clean, hash:0/0) handler=(nil)^M
RSP-0x20:0x0000003800218038 RSP-0x18:0x0000000000000001 RSP-0x10:0x0000000036df5dc0 RSP-0x08:0x0000000000000005^M
RSP+0x00:0x0000003f03714f77 RSP+0x08:0x0000000000000000 RSP+0x10:0x0000003800218070 RSP+0x18:0x0000003800218030^M
RAX:0x0000003800218070 RCX:0x0000003800218070 RDX:0x0000003800218038 RBX:0x0000003800218038 ^M
RSP:0x0000003ff7bfe980 RBP:0x0000000000000000 RSI:0x0000003800218038 RDI:0x0000003800218030 ^M
 R8:0x000000000000003f  R9:0x0000003800218038 R10:0x000000000000b000 R11:0x000000010ca097c0 ^M
R12:0x0000003800210288 R13:0x0000000000000002 R14:0x0000003800218080 R15:0x0000003800210280 ES:0x002b CS:0x0033 SS:0x002b DS:0x002b FS:0x0000 GS:0x0000 FSBASE=0x36def970 GSBASE=(nil)^M

With BOX64_MALLOC_HACK=2 :

[BOX64] 74342|SIGSEGV @0x3ff7efd0f2 (syscall(/usr/lib/riscv64-linux-gnu/libc.so.6)) (x64pc=0x30232e73/"box64/syscall(/usr/lib/riscv64-linux-gnu/libc.so.6) + 0x13", rsp=0x60a42740, stack=0x3ff7400000:0x3ff7c00000 own=(nil) fp=0x60a42808), for accessing 0xbadbad34baec6ef8 (code=1/prot=0), db=(nil)((nil):(nil)/(nil):(nil)/???:clean, hash:0/0) handler=(nil)^M
RSP-0x20:0xaaaaaaaaaaaaaaaa RSP-0x18:0xaaaaaaaaaaaaaaaa RSP-0x10:0xaaaaaaaaaaaaaaaa RSP-0x08:0xaaaaaaaaaaaaaaaa^M
RSP+0x00:0x000000010897dbb3 RSP+0x08:0xaaaaaaaaaaaaaaaa RSP+0x10:0x0000000000000000 RSP+0x18:0x0000000000000000^M
RAX:0x0000000000000000 RCX:0x000000000000000b RDX:0x0000000000012266 RBX:0x0000000060a42c30 ^M
RSP:0x0000000060a42740 RBP:0x0000000060a42808 RSI:0x0000000000012266 RDI:0x0000000000000129 ^M
 R8:0x0000000060a42c30  R9:0x0000000000000000 R10:0x0000000000000000 R11:0x0000000000000010 ^M
R12:0x0000000036f34908 R13:0x0000000060a42820 R14:0x000000000000000b R15:0x0000000000012266 ES:0x002b CS:0x0033 SS:0x002b DS:0x002b FS:0x0000 GS:0x0000 FSBASE=0x36df0b80 GSBASE=(nil)^M

Full log:

box64_wechat_20260204_without_mallochack2.txt
box64_wechat_20260204_with_mallochack2.txt

[ksco]

This is the K3 right? Would be good if SpacemiT could provide an SSH access to us.

[zqb-all]

This is the K3 right? Would be good if SpacemiT could provide an SSH access to us.

Yes, this is K3. I also hope that excellent projects like box64 can start using the K3 as soon as possible. I will discuss internally the possibility of providing access.

[ksco]

Thank you!