Messages in this thread | | | Date | Mon, 4 Mar 2019 06:23:32 -0600 | From | Segher Boessenkool <> | Subject | Re: [PATCH 2/6] ptrace: introduce ptrace_syscall_enter to consolidate PTRACE_SYSEMU handling |
| |
On Mon, Mar 04, 2019 at 10:46:43AM +0000, Sudeep Holla wrote: > On Mon, Mar 04, 2019 at 08:03:47AM +0000, Haibo Xu (Arm Technology China) wrote: > > On 2019/3/1 2:32, Sudeep Holla wrote: > > > +long ptrace_syscall_enter(struct pt_regs *regs) > > > +{ > > > +#ifdef TIF_SYSCALL_EMU > > > + if (test_thread_flag(TIF_SYSCALL_EMU)) { > > > + if (tracehook_report_syscall_entry(regs)); > > > > Shall we remove the semi-colon at end of the above line? > > Added intentionally to keep GCC happy.
GCC warns because the user explicitly asked for it, with __must_check. If you want to do things with an "if" like this, you should write e.g.
if (tracehook_report_syscall_entry(regs)) /* * We can ignore the return code here, because of * X and Y and Z. */ ;
Or it probably is nicer to use a block:
if (tracehook_report_syscall_entry(regs)) { /* * We can ignore the return code here, because of * X and Y and Z. */ }
The point is, you *always* should have a nice fat comment if you are ignoring the return code of a __must_check function.
Segher
| |