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

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

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--