Re: kern/59608: compat_linux should ignore LINUX_CLONE_SYSVSEM and handle stack grows down

[mc36 <csmate%nop.hu@localhost>]

hi,

resending the patch, just in case.... without it, one cannot have a recent java running:

nb# /emul/linux/jdk-26/bin/java
[0.021s][warning][os,thread] Failed to start thread "VM Periodic Task Thread" - pthread_create failed (EINVAL) for attributes: stacksize: 1024k, guardsize: 4k, detached.
[0.083s][warning][os,thread] Failed to start thread "VM Thread" - pthread_create failed (EINVAL) for attributes: stacksize: 1024k, guardsize: 4k, detached.
Error occurred during initialization of VM
Cannot create VM thread. Out of system resources.
nb#


steps to reproduce:

- have the latest netbsd-11-beta up and running

- extract a rootfs (i used https://deb.debian.org/debian/dists/sid/main/installer-amd64/current/images/cdrom/initrd.gz ) to /emul/linux

- extract the latest jvm (i used https://download.java.net/java/early_access/jdk26/14/GPL/openjdk-26-ea+14_linux-x64_bin.tar.gz ) there


so please merge to have this fixed....

all the best,

csaba



On 8/28/25 17:15, mc36 wrote:
> The following reply was made to PR kern/59608; it has been noted by GNATS.
>
> From: mc36 <csmate%nop.hu@localhost>
> To: gnats-bugs%netbsd.org@localhost, mc36%freemail.hu@localhost, netbsd-bugs%netbsd.org@localhost,
>   kern-bug-people%netbsd.org@localhost
> Cc:
> Subject: Re: kern/59608: compat_linux should ignore LINUX_CLONE_SYSVSEM and
>   assume stack grows down
> Date: Thu, 28 Aug 2025 17:05:00 +0200
>
>   This is a multi-part message in MIME format.
>   --------------pmG9mb0CegYxhSB01l81wBsR
>   Content-Type: text/plain; charset=UTF-8; format=flowed
>   Content-Transfer-Encoding: 7bit
>   
>   hi,
>   
>   just a quick up on this, as maybe i should clarified that glibc blindly uses the
>   
>   clone_sysvsem: https://codebrowser.dev/glibc/glibc/nptl/pthread_create.c.html#279
>   
>   and, since there is a clone3 syscall now, that returns einval because of the flag,
>   
>   https://codebrowser.dev/glibc/glibc/sysdeps/unix/sysv/linux/clone-internal.c.html#47
>   
>   so the fallback never reaches, rendering multithreading unusable in binary emulation...
>   
>   
>   
>   the (updated, reattached) patch addresses the flag to slip through the checks,
>   
>   and later gets ignored, and then points the stack pointer to the proper location,
>   
>   restoring the pthread_create functionality... applying the patch to the 11-beta
>   
>   (and seemingly 10-daily also needs this) passes the simple test code i sent earlier.
>   
>   awaiting your feedback on merging if you find it appropriate... :)
>   
>   ps: this time i added the ifdef to check the stack-grows-up/down behavior....
>   
>   all the best,
>   
>   csaba
>   
>   
>   
>   
>   
>   On 8/25/25 21:20, gnats-admin%netbsd.org@localhost wrote:
>   > Thank you very much for your problem report.
>   > It has the internal identification `kern/59608'.
>   > The individual assigned to look at your
>   > report is: kern-bug-people.
>   >
>   >> Category:       kern
>   >> Responsible:    kern-bug-people
>   >> Synopsis:       compat_linux should ignore LINUX_CLONE_SYSVSEM and assume stack grows down
>   >> Arrival-Date:   Mon Aug 25 19:20:00 +0000 2025
>   >
>   
>   --------------pmG9mb0CegYxhSB01l81wBsR
>   Content-Type: text/x-patch; charset=UTF-8; name="netbsd-clone3.patch"
>   Content-Disposition: attachment; filename="netbsd-clone3.patch"
>   Content-Transfer-Encoding: base64
>   
>   LS0tIHNyYy5iYWQvc3lzL2NvbXBhdC9saW51eC9jb21tb24vbGludXhfc2NoZWQuaAkyMDI0
>   LTA5LTI4IDIxOjM1OjU2LjAwMDAwMDAwMCArMDIwMAorKysgc3JjLm9rL3N5cy9jb21wYXQv
>   bGludXgvY29tbW9uL2xpbnV4X3NjaGVkLmgJMjAyNS0wOC0yNSAyMDo0ODoxMC41MzExMTU3
>   MzggKzAyMDAKQEAgLTg1LDcgKzg1LDcgQEAKICAgICBMSU5VWF9DTE9ORV9WTSB8IExJTlVY
>   X0NMT05FX0ZTIHwgTElOVVhfQ0xPTkVfRklMRVMgfCBcCiAgICAgTElOVVhfQ0xPTkVfU0lH
>   SEFORCB8IExJTlVYX0NMT05FX1RIUkVBRCB8IExJTlVYX0NMT05FX1ZGT1JLIHwgXAogICAg
>   IExJTlVYX0NMT05FX1BBUkVOVF9TRVRUSUQgfCBMSU5VWF9DTE9ORV9DSElMRF9DTEVBUlRJ
>   RCB8IFwKLSAgICBMSU5VWF9DTE9ORV9DSElMRF9TRVRUSUQgfCBMSU5VWF9DTE9ORV9TRVRU
>   TFMpCisgICAgTElOVVhfQ0xPTkVfQ0hJTERfU0VUVElEIHwgTElOVVhfQ0xPTkVfU0VUVExT
>   IHwgTElOVVhfQ0xPTkVfU1lTVlNFTSkKIAogI2RlZmluZSBMSU5VWF9DTE9ORV9VTklNUExF
>   TUVOVEVEX0ZMQUdTICggXAogICAgIExJTlVYX0NMT05FX05FV05TIHwgTElOVVhfQ0xPTkVf
>   TkVXVVRTIHwgTElOVVhfQ0xPTkVfTkVXSVBDIHwgXAotLS0gc3JjLmJhZC9zeXMvY29tcGF0
>   L2xpbnV4L2NvbW1vbi9saW51eF9zY2hlZC5jCTIwMjQtMTAtMDMgMTQ6NTY6NDkuMDAwMDAw
>   MDAwICswMjAwCisrKyBzcmMub2svc3lzL2NvbXBhdC9saW51eC9jb21tb24vbGludXhfc2No
>   ZWQuYwkyMDI1LTA4LTI3IDA5OjAzOjU2LjU3MTMzODI4NSArMDIwMApAQCAtMjMwLDcgKzIz
>   MCwxMSBAQAogICAgLy8gWFhYOiBjbG9uZTMgaGFzIHN0YWNrc2l6ZSwgaW5zdGVhZCBpbXBs
>   ZW1lbnQgY2xvbmUgYXMgYSBjbG9uZTMKICAgIC8vIHdyYXBwZXIuCiAgICBTQ0FSRygmY2xv
>   bmVfYXJncywgZmxhZ3MpID0gZmxhZ3M7CisjaWZkZWYgX19NQUNISU5FX1NUQUNLX0dST1dT
>   X1VQCiAgICBTQ0FSRygmY2xvbmVfYXJncywgc3RhY2spID0gKHZvaWQgKikodWludHB0cl90
>   KWNsX2FyZ3Muc3RhY2s7CisjZWxzZQorCVNDQVJHKCZjbG9uZV9hcmdzLCBzdGFjaykgPSAo
>   dm9pZCAqKSgodWludHB0cl90KWNsX2FyZ3Muc3RhY2sgKyAodWludHB0cl90KWNsX2FyZ3Mu
>   c3RhY2tfc2l6ZSk7CisjZW5kaWYKICAgIFNDQVJHKCZjbG9uZV9hcmdzLCBwYXJlbnRfdGlk
>   cHRyKSA9CiAgICAgICAgKHZvaWQgKikoaW50cHRyX3QpY2xfYXJncy5wYXJlbnRfdGlkOwog
>   ICAgU0NBUkcoJmNsb25lX2FyZ3MsIHRscykgPQo=
>   
>   --------------pmG9mb0CegYxhSB01l81wBsR--
>   
--- src.bad/sys/compat/linux/common/linux_sched.h	2024-09-28 21:35:56.000000000 +0200
+++ src.ok/sys/compat/linux/common/linux_sched.h	2025-08-25 20:48:10.531115738 +0200
@@ -85,7 +85,7 @@
     LINUX_CLONE_VM | LINUX_CLONE_FS | LINUX_CLONE_FILES | \
     LINUX_CLONE_SIGHAND | LINUX_CLONE_THREAD | LINUX_CLONE_VFORK | \
     LINUX_CLONE_PARENT_SETTID | LINUX_CLONE_CHILD_CLEARTID | \
-    LINUX_CLONE_CHILD_SETTID | LINUX_CLONE_SETTLS)
+    LINUX_CLONE_CHILD_SETTID | LINUX_CLONE_SETTLS | LINUX_CLONE_SYSVSEM)
 
 #define LINUX_CLONE_UNIMPLEMENTED_FLAGS ( \
     LINUX_CLONE_NEWNS | LINUX_CLONE_NEWUTS | LINUX_CLONE_NEWIPC | \
--- src.bad/sys/compat/linux/common/linux_sched.c	2024-10-03 14:56:49.000000000 +0200
+++ src.ok/sys/compat/linux/common/linux_sched.c	2025-09-11 08:10:27.302327397 +0200
@@ -230,7 +230,11 @@
 	// XXX: clone3 has stacksize, instead implement clone as a clone3
 	// wrapper.
 	SCARG(&clone_args, flags) = flags;
+#ifdef __MACHINE_STACK_GROWS_UP
 	SCARG(&clone_args, stack) = (void *)(uintptr_t)cl_args.stack;
+#else
+	SCARG(&clone_args, stack) = (void *)((uintptr_t)cl_args.stack + (uintptr_t)cl_args.stack_size);
+#endif
 	SCARG(&clone_args, parent_tidptr) =
 	    (void *)(intptr_t)cl_args.parent_tid;
 	SCARG(&clone_args, tls) =