Re: [RFC] entry: Untangle the return value of syscall_enter_from_user_mode from syscall NR
From: Thomas Gleixner <tglx@kernel.org>
Date: 2026-07-06 08:17:14
Also in:
linux-doc, linux-riscv, linux-s390, lkml, loongarch
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.