On Wed, May 01, 2019 at 01:04:51PM -0700, Sami Tolvanen wrote: > Although a syscall defined using SYSCALL_DEFINE0 doesn't accept > parameters, use the correct function type to avoid indirect call > type mismatches with Control-Flow Integrity checking.
Generally, this makes sense, but I'm not sure that this is complete. IIUC this introduces a new type mismatch with sys_ni_syscall() in some cases. We probably need that to use SYSCALL_DEFINE0(), and maybe have a ksys_ni_syscall() for in-kernel wrappers. Thanks, Mark. > > Signed-off-by: Sami Tolvanen <samitolva...@google.com> > --- > arch/arm64/include/asm/syscall_wrapper.h | 18 +++++++++--------- > 1 file changed, 9 insertions(+), 9 deletions(-) > > diff --git a/arch/arm64/include/asm/syscall_wrapper.h > b/arch/arm64/include/asm/syscall_wrapper.h > index a4477e515b798..507d0ee6bc690 100644 > --- a/arch/arm64/include/asm/syscall_wrapper.h > +++ b/arch/arm64/include/asm/syscall_wrapper.h > @@ -30,10 +30,10 @@ > } > \ > static inline long __do_compat_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__)) > > -#define COMPAT_SYSCALL_DEFINE0(sname) > \ > - asmlinkage long __arm64_compat_sys_##sname(void); \ > - ALLOW_ERROR_INJECTION(__arm64_compat_sys_##sname, ERRNO); \ > - asmlinkage long __arm64_compat_sys_##sname(void) > +#define COMPAT_SYSCALL_DEFINE0(sname) > \ > + asmlinkage long __arm64_compat_sys_##sname(const struct pt_regs > *__unused); \ > + ALLOW_ERROR_INJECTION(__arm64_compat_sys_##sname, ERRNO); > \ > + asmlinkage long __arm64_compat_sys_##sname(const struct pt_regs > *__unused) > > #define COND_SYSCALL_COMPAT(name) \ > cond_syscall(__arm64_compat_sys_##name); > @@ -62,11 +62,11 @@ > static inline long __do_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__)) > > #ifndef SYSCALL_DEFINE0 > -#define SYSCALL_DEFINE0(sname) \ > - SYSCALL_METADATA(_##sname, 0); \ > - asmlinkage long __arm64_sys_##sname(void); \ > - ALLOW_ERROR_INJECTION(__arm64_sys_##sname, ERRNO); \ > - asmlinkage long __arm64_sys_##sname(void) > +#define SYSCALL_DEFINE0(sname) > \ > + SYSCALL_METADATA(_##sname, 0); > \ > + asmlinkage long __arm64_sys_##sname(const struct pt_regs *__unused); > \ > + ALLOW_ERROR_INJECTION(__arm64_sys_##sname, ERRNO); > \ > + asmlinkage long __arm64_sys_##sname(const struct pt_regs *__unused) > #endif > > #ifndef COND_SYSCALL > -- > 2.21.0.593.g511ec345e18-goog >
