From: Thomas Gleixner <tglx@kernel.org>
To: "Michal Suchánek" <msuchanek@suse.de>,
"Peter Zijlstra" <peterz@infradead.org>
Cc: "Jonathan Corbet" <corbet@lwn.net>,
"Shuah Khan" <skhan@linuxfoundation.org>,
"Huacai Chen" <chenhuacai@kernel.org>,
"WANG Xuerui" <kernel@xen0n.name>,
"Madhavan Srinivasan" <maddy@linux.ibm.com>,
"Michael Ellerman" <mpe@ellerman.id.au>,
"Nicholas Piggin" <npiggin@gmail.com>,
"Christophe Leroy (CS GROUP)" <chleroy@kernel.org>,
"Paul Walmsley" <pjw@kernel.org>,
"Palmer Dabbelt" <palmer@dabbelt.com>,
"Albert Ou" <aou@eecs.berkeley.edu>,
"Alexandre Ghiti" <alex@ghiti.fr>,
"Heiko Carstens" <hca@linux.ibm.com>,
"Vasily Gorbik" <gor@linux.ibm.com>,
"Alexander Gordeev" <agordeev@linux.ibm.com>,
"Christian Borntraeger" <borntraeger@linux.ibm.com>,
"Sven Schnelle" <svens@linux.ibm.com>,
"Andy Lutomirski" <luto@kernel.org>,
"Ingo Molnar" <mingo@redhat.com>,
"Borislav Petkov" <bp@alien8.de>,
"Dave Hansen" <dave.hansen@linux.intel.com>,
x86@kernel.org, "H. Peter Anvin" <hpa@zytor.com>,
"Andrew Donnellan" <andrew+kernel@donnellan.id.au>,
"Mark Rutland" <mark.rutland@arm.com>,
"Michal Suchánek" <msuchanek@suse.de>,
"Arnd Bergmann" <arnd@arndb.de>,
"Jiaxun Yang" <jiaxun.yang@flygoat.com>,
"Ryan Roberts" <ryan.roberts@arm.com>,
"Greg Kroah-Hartman" <gregkh@linuxfoundation.org>,
"Mukesh Kumar Chaurasiya" <mkchauras@linux.ibm.com>,
"Shrikanth Hegde" <sshegde@linux.ibm.com>,
"Zong Li" <zong.li@sifive.com>, "Nam Cao" <namcao@linutronix.de>,
"Deepak Gupta" <debug@rivosinc.com>,
"Lukas Gerlach" <lukas.gerlach@cispa.de>,
"Rui Qi" <qirui.001@bytedance.com>, "Kees Cook" <kees@kernel.org>,
linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org,
loongarch@lists.linux.dev, linuxppc-dev@lists.ozlabs.org,
linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org
Subject: Re: [RFC] entry: Untangle the return value of syscall_enter_from_user_mode from syscall NR
Date: Mon, 06 Jul 2026 10:16:57 +0200 [thread overview]
Message-ID: <87ik6sjzwm.ffs@fw13> (raw)
In-Reply-To: <akVRcPsD_R_CE1qW@kunlun.suse.cz>
On Wed, Jul 01 2026 at 19:42, Michal Suchánek wrote:
>
> if (unlikely(work & SYSCALL_WORK_SYSCALL_TRACEPOINT))
> - syscall = trace_syscall_enter(regs, syscall);
> + *syscall = trace_syscall_enter(regs, *syscall);
>
> - syscall_enter_audit(regs, syscall);
> + syscall_enter_audit(regs, *syscall);
>
> - return ret ? : syscall;
> + return 0;
That breaks trace_syscall_enter() because the probes/BPF muck attached
ot that can:
1) set the return code
2) set syscall to -1L
That works correctly today, but with your sloppy hackery the low level
x86 code falls into sys_ni_syscall() which sets the return code to
-ENOSYS.
prev parent reply other threads:[~2026-07-06 8:17 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-07-01 17:42 [RFC] entry: Untangle the return value of syscall_enter_from_user_mode from syscall NR Michal Suchánek
2026-07-01 18:29 ` H. Peter Anvin
2026-07-02 9:30 ` Michal Suchánek
2026-07-02 21:49 ` Thomas Gleixner
2026-07-03 6:26 ` Sven Schnelle
2026-07-03 9:25 ` Peter Zijlstra
2026-07-03 9:27 ` Thomas Gleixner
2026-07-03 9:59 ` Sven Schnelle
2026-07-03 10:57 ` Peter Zijlstra
2026-07-03 11:17 ` Sven Schnelle
2026-07-03 11:25 ` Michal Suchánek
2026-07-03 11:39 ` Sven Schnelle
2026-07-04 17:18 ` H. Peter Anvin
2026-07-06 5:27 ` Sven Schnelle
2026-07-04 17:23 ` H. Peter Anvin
2026-07-02 8:12 ` Sven Schnelle
2026-07-02 9:12 ` Michal Suchánek
2026-07-02 12:01 ` Sven Schnelle
2026-07-02 12:13 ` Michal Suchánek
2026-07-03 6:16 ` Sven Schnelle
2026-07-02 11:24 ` Thomas Gleixner
2026-07-02 11:45 ` Michal Suchánek
2026-07-02 20:45 ` Thomas Gleixner
2026-07-03 7:53 ` Michal Suchánek
2026-07-03 9:34 ` Thomas Gleixner
2026-07-06 8:16 ` Thomas Gleixner [this message]
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