On Mon, Dec 22, 2025 at 07:47:25PM +0800, Jinjie Ruan wrote: > The generic syscall entry code has the following form, which use > the input syscall work flag and syscall number: > > | syscall_trace_enter(struct pt_regs *regs, long syscall, > | unsigned long work) > | > | syscall_exit_work(struct pt_regs *regs, unsigned long work) > > In preparation for moving arm64 over to the generic entry code, > refactor syscall_trace_enter/exit() to also pass thread flags, and > get syscall number by syscall_get_nr() helper. > > No functional changes. > > Reviewed-by: Kevin Brodsky <[email protected]> > Signed-off-by: Jinjie Ruan <[email protected]> > --- > arch/arm64/include/asm/syscall.h | 4 ++-- > arch/arm64/kernel/ptrace.c | 25 ++++++++++++++++--------- > arch/arm64/kernel/syscall.c | 5 +++-- > 3 files changed, 21 insertions(+), 13 deletions(-) > > diff --git a/arch/arm64/include/asm/syscall.h > b/arch/arm64/include/asm/syscall.h > index 5e4c7fc44f73..cef1d9ce6e1b 100644 > --- a/arch/arm64/include/asm/syscall.h > +++ b/arch/arm64/include/asm/syscall.h > @@ -120,7 +120,7 @@ static inline int syscall_get_arch(struct task_struct > *task) > return AUDIT_ARCH_AARCH64; > } > > -int syscall_trace_enter(struct pt_regs *regs); > -void syscall_trace_exit(struct pt_regs *regs); > +int syscall_trace_enter(struct pt_regs *regs, long syscall, unsigned long > flags); > +void syscall_trace_exit(struct pt_regs *regs, unsigned long flags); > > #endif /* __ASM_SYSCALL_H */ > diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c > index f333791ffba6..79762ff33945 100644 > --- a/arch/arm64/kernel/ptrace.c > +++ b/arch/arm64/kernel/ptrace.c > @@ -2407,9 +2407,8 @@ static void report_syscall_exit(struct pt_regs *regs) > } > } > > -int syscall_trace_enter(struct pt_regs *regs) > +int syscall_trace_enter(struct pt_regs *regs, long syscall, unsigned long > flags) > { > - unsigned long flags = read_thread_flags(); > int ret; > > if (flags & (_TIF_SYSCALL_EMU | _TIF_SYSCALL_TRACE)) { > @@ -2422,19 +2421,27 @@ int syscall_trace_enter(struct pt_regs *regs) > if (secure_computing() == -1) > return NO_SYSCALL; > > - if (test_thread_flag(TIF_SYSCALL_TRACEPOINT)) > - trace_sys_enter(regs, regs->syscallno); > + /* Either of the above might have changed the syscall number */ > + syscall = syscall_get_nr(current, regs);
I understand that you're gradually making the arch code more similar to the core code so that we can switch over to it, but I'm struggling to understand why syscall_trace_enter() takes the 'syscall' argument. Even the core code just seems to use it as a local variable, which it overrides before it ever uses it. What am I missing? Will
