Re: Linux 6.18-rc6

["David Wang" <00107082@163.com>]

At 2025-11-17 18:33:58, "Linus Torvalds" <torvalds@linux-foundation.org> wrote:
>On Mon, 17 Nov 2025 at 00:20, David Wang <00107082@163.com> wrote:
>>
>> After upgrade to 6.18-rc6, all my golang programs start to crash, even Go compiler crashes;
>> and when I started bisect, `make vmlinux` crashes too.
>
>Funky funky. Certainly doesn't happen here.
>
>> I am running bisect with 6.18-rc5 now, any chance this has already caught/fixed?
>
>Please do run the bisect (obviously you'll have to build using a
>kernel that works for you), I am not aware of anybody reporting
>anything like this.

Hi,

Bisect narrowed it down to 
[adfb6609c6809e107ded9a1cd46f519c882e64ea] mm/huge_memory: initialise the tags of the huge zero folio

It seems happen to program build with older version of go, mine is 1.18.4;   and I cannot reproduce it with go1.25.4.

When I upgraded to 6.18-rc6,  go1.18.4 compiler/program would crash with,

    fatal error: arena already initialized
    
    runtime stack:
    runtime.throw({0x9ea9fe?, 0x0?})
	    /usr/local/go/src/runtime/panic.go:992 +0x71 fp=0x7ffdf458a248 sp=0x7ffdf458a218 pc=0x435ab1
    runtime.(*mheap).sysAlloc(0xddec20, 0x0?)
	    /usr/local/go/src/runtime/malloc.go:749 +0x2e9 fp=0x7ffdf458a2e0 sp=0x7ffdf458a248 pc=0x40dee9
    ...


And when I `make vmlinux`, I got something like this :
	  AR      vmlinux.a
	  LD      vmlinux.o
	  GEN     .vmlinux.objs
	  MODPOST vmlinux.symvers
	  CC      .vmlinux.export.o
	  UPD     include/generated/utsversion.h
	  CC      init/version-timestamp.o
	  KSYMS   .tmp_vmlinux0.kallsyms.S
	  AS      .tmp_vmlinux0.kallsyms.o
	  LD      .tmp_vmlinux1
	  NM      .tmp_vmlinux1.syms
	  KSYMS   .tmp_vmlinux1.kallsyms.S
	  AS      .tmp_vmlinux1.kallsyms.o
	.tmp_vmlinux1.kallsyms.S:361542:19: internal compiler error: Aborted
	361542 |         .byte 0x00, 0x99, 0xe9  /* T__pfx___x64_sys_inotify_add_watch */
	       |                   ^
	0x7f983a551def ???
		./signal/../sysdeps/unix/sysv/linux/x86_64/libc_sigaction.c:0
	0x7f983a5a695c __pthread_kill_implementation
		./nptl/pthread_kill.c:44
	0x7f983a551cc1 __GI_raise
		../sysdeps/posix/raise.c:26
	0x7f983a53a4ab __GI_abort
		./stdlib/abort.c:73
	0x7f983a53bca7 __libc_start_call_main
		../sysdeps/nptl/libc_start_call_main.h:58
	0x7f983a53bd64 __libc_start_main_impl
		../csu/libc-start.c:360
	Please submit a full bug report, with preprocessed source (by using -freport-bug).
	Please include the complete backtrace with any bug report.
	See <file:///usr/share/doc/gcc-14/README.Bugs> for instructions.
	make[2]: *** [scripts/Makefile.vmlinux:72: vmlinux.unstripped] Error 1
	make[1]: *** [/home/linan/codes/linux-kernel/linux/Makefile:1242: vmlinux] Error 2
	make: *** [Makefile:248: __sub-make] Error 2
$ gcc --version
gcc (Debian 14.2.0-19) 14.2.0

(It dose not always happens, sometimes I don't get this crash and It dose not always err on same line.)

And nothing abnormal shows up in kernel message.

Revert adfb6609c6809e107ded9a1cd46f519c882e64ea can fix my crashing go programs.



FYI
David