Messages in this thread | | | From | Michael Ellerman <> | Subject | Re: [PATCH v3] powerpc/ptrace: replace ptrace_report_syscall() with a tracehook call | Date | Thu, 22 Nov 2018 08:17:25 +1100 |
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Hi Dmitry,
Thanks for the patch.
"Dmitry V. Levin" <ldv@altlinux.org> writes: > From: Elvira Khabirova <lineprinter@altlinux.org> > > Arch code should use tracehook_*() helpers as documented > in include/linux/tracehook.h, > ptrace_report_syscall() is not expected to be used outside that file. > > Co-authored-by: Dmitry V. Levin <ldv@altlinux.org> > Fixes: 5521eb4bca2d ("powerpc/ptrace: Add support for PTRACE_SYSEMU") > Signed-off-by: Elvira Khabirova <lineprinter@altlinux.org> > Signed-off-by: Dmitry V. Levin <ldv@altlinux.org> > --- > > v3: add a descriptive comment > v2: explicitly ignore tracehook_report_syscall_entry() return code > > arch/powerpc/kernel/ptrace.c | 7 ++++++- > 1 file changed, 6 insertions(+), 1 deletion(-) > > diff --git a/arch/powerpc/kernel/ptrace.c b/arch/powerpc/kernel/ptrace.c > index afb819f4ca68..e84220d91bbd 100644 > --- a/arch/powerpc/kernel/ptrace.c > +++ b/arch/powerpc/kernel/ptrace.c > @@ -3266,7 +3266,12 @@ long do_syscall_trace_enter(struct pt_regs *regs) > user_exit(); > > if (test_thread_flag(TIF_SYSCALL_EMU)) { > - ptrace_report_syscall(regs); > + /* > + * A nonzero return code from tracehook_report_syscall_entry() > + * tells us to prevent the syscall execution, but we are not > + * going to execute it anyway. > + */ > + (void) tracehook_report_syscall_entry(regs);
Unfortunately the (void) cast doesn't work to suppress the must check warning.
arch/powerpc/kernel/ptrace.c:3274:3: error: ignoring return value of 'tracehook_report_syscall_entry', declared with attribute warn_unused_result [-Werror=unused-result]
AFAIK we don't have a way to suppress that.
I guess we should rewrite it to only call tracehook_report_syscall_entry() once, like x86 does.
I'll try and get a patch for that done & tested.
cheers
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