On Tue, Mar 17, 2026 at 9:20 AM Jinjie Ruan <[email protected]> wrote:
> Refactor the system call exit path to align with the generic entry > framework. This consolidates thread flag checking, rseq handling, and > syscall tracing into a structure that mirrors the generic > syscall_exit_to_user_mode_work() implementation. > > [Rationale] > The generic entry code employs a hierarchical approach for > syscall exit work: > > 1. syscall_exit_to_user_mode_work(): The entry point that handles > rseq and checks if further exit work (tracing/audit) is required. > > 2. syscall_exit_work(): Performs the actual tracing, auditing, and > ptrace reporting. > > [Changes] > - Rename and Encapsulate: Rename syscall_trace_exit() to > syscall_exit_work() and make it static, as it is now an internal > helper for the exit path. > > - New Entry Point: Implement syscall_exit_to_user_mode_work() to > replace the manual flag-reading logic in el0_svc_common(). This > function now encapsulates the rseq_syscall() call and the > conditional execution of syscall_exit_work(). > > - Simplify el0_svc_common(): Remove the complex conditional checks > for tracing and CONFIG_DEBUG_RSEQ at the end of the syscall path, > delegating this responsibility to the new helper. > > - Helper Migration: Move has_syscall_work() to asm/syscall.h > to allow its reuse across ptrace.c and syscall.c. > > - Clean up RSEQ: Remove the explicit IS_ENABLED(CONFIG_DEBUG_RSEQ) > check in the caller, as rseq_syscall() is already a no-op when the > config is disabled. > > Cc: Will Deacon <[email protected]> > Cc: Catalin Marinas <[email protected]> > Reviewed-by: Kevin Brodsky <[email protected]> > Signed-off-by: Jinjie Ruan <[email protected]> Reviewed-by: Linus Walleij <[email protected]> Yours, Linus Walleij
