On Fri, 30 Apr 2021 at 19:42, Eric W. Biederman <ebiederm@xxxxxxxxxxxx> wrote: > > Marco Elver <elver@xxxxxxxxxx> writes: > > > To help catch ABI breaks at compile-time, add compile-time assertions to > > verify the siginfo_t layout. Unlike other architectures, sparc64 is > > special, because it is one of few architectures requiring si_trapno. > > ABI breaks around that field would only be caught here. > > Arnd Bergman recently pointed out that we can move si_trapno into the > union and make it specific to a handful of signals. Like we do other > items in the union. > > Given that the code of perf_sigtrap is pretty much broken if si_trapno > needs to be filled out. I think we should make that change before > we set this ABI in stone like this. > > Otherwise this looks good. Thanks, that's reasonable -- I'll reply to the other thread in a few minutes. -- Marco > Eric > > > Link: https://lkml.kernel.org/r/m11rat9f85.fsf@xxxxxxxxxxxxxxxxx > > Suggested-by: Eric W. Biederman <ebiederm@xxxxxxxxxxxx> > > Signed-off-by: Marco Elver <elver@xxxxxxxxxx> > > --- > > arch/sparc/kernel/signal32.c | 34 ++++++++++++++++++++++++++++++++++ > > arch/sparc/kernel/signal_64.c | 33 +++++++++++++++++++++++++++++++++ > > 2 files changed, 67 insertions(+) > > > > diff --git a/arch/sparc/kernel/signal32.c b/arch/sparc/kernel/signal32.c > > index e9695a06492f..778ed5c26d4a 100644 > > --- a/arch/sparc/kernel/signal32.c > > +++ b/arch/sparc/kernel/signal32.c > > @@ -745,3 +745,37 @@ asmlinkage int do_sys32_sigstack(u32 u_ssptr, u32 u_ossptr, unsigned long sp) > > out: > > return ret; > > } > > + > > +/* > > + * Compile-time assertions for siginfo_t offsets. Check NSIG* as well, as > > + * changes likely come with new fields that should be added below. > > + */ > > +static_assert(NSIGILL == 11); > > +static_assert(NSIGFPE == 15); > > +static_assert(NSIGSEGV == 9); > > +static_assert(NSIGBUS == 5); > > +static_assert(NSIGTRAP == 6); > > +static_assert(NSIGCHLD == 6); > > +static_assert(NSIGSYS == 2); > > +static_assert(offsetof(compat_siginfo_t, si_signo) == 0x00); > > +static_assert(offsetof(compat_siginfo_t, si_errno) == 0x04); > > +static_assert(offsetof(compat_siginfo_t, si_code) == 0x08); > > +static_assert(offsetof(compat_siginfo_t, si_pid) == 0x0c); > > +static_assert(offsetof(compat_siginfo_t, si_uid) == 0x10); > > +static_assert(offsetof(compat_siginfo_t, si_tid) == 0x0c); > > +static_assert(offsetof(compat_siginfo_t, si_overrun) == 0x10); > > +static_assert(offsetof(compat_siginfo_t, si_status) == 0x14); > > +static_assert(offsetof(compat_siginfo_t, si_utime) == 0x18); > > +static_assert(offsetof(compat_siginfo_t, si_stime) == 0x1c); > > +static_assert(offsetof(compat_siginfo_t, si_value) == 0x14); > > +static_assert(offsetof(compat_siginfo_t, si_int) == 0x14); > > +static_assert(offsetof(compat_siginfo_t, si_ptr) == 0x14); > > +static_assert(offsetof(compat_siginfo_t, si_addr) == 0x0c); > > +static_assert(offsetof(compat_siginfo_t, si_trapno) == 0x10); > > +static_assert(offsetof(compat_siginfo_t, si_addr_lsb) == 0x14); > > +static_assert(offsetof(compat_siginfo_t, si_lower) == 0x18); > > +static_assert(offsetof(compat_siginfo_t, si_upper) == 0x1c); > > +static_assert(offsetof(compat_siginfo_t, si_pkey) == 0x18); > > +static_assert(offsetof(compat_siginfo_t, si_perf) == 0x14); > > +static_assert(offsetof(compat_siginfo_t, si_band) == 0x0c); > > +static_assert(offsetof(compat_siginfo_t, si_fd) == 0x10); > > diff --git a/arch/sparc/kernel/signal_64.c b/arch/sparc/kernel/signal_64.c > > index a0eec62c825d..c9bbf5f29078 100644 > > --- a/arch/sparc/kernel/signal_64.c > > +++ b/arch/sparc/kernel/signal_64.c > > @@ -556,3 +556,36 @@ void do_notify_resume(struct pt_regs *regs, unsigned long orig_i0, unsigned long > > user_enter(); > > } > > > > +/* > > + * Compile-time assertions for siginfo_t offsets. Check NSIG* as well, as > > + * changes likely come with new fields that should be added below. > > + */ > > +static_assert(NSIGILL == 11); > > +static_assert(NSIGFPE == 15); > > +static_assert(NSIGSEGV == 9); > > +static_assert(NSIGBUS == 5); > > +static_assert(NSIGTRAP == 6); > > +static_assert(NSIGCHLD == 6); > > +static_assert(NSIGSYS == 2); > > +static_assert(offsetof(siginfo_t, si_signo) == 0x00); > > +static_assert(offsetof(siginfo_t, si_errno) == 0x04); > > +static_assert(offsetof(siginfo_t, si_code) == 0x08); > > +static_assert(offsetof(siginfo_t, si_pid) == 0x10); > > +static_assert(offsetof(siginfo_t, si_uid) == 0x14); > > +static_assert(offsetof(siginfo_t, si_tid) == 0x10); > > +static_assert(offsetof(siginfo_t, si_overrun) == 0x14); > > +static_assert(offsetof(siginfo_t, si_status) == 0x18); > > +static_assert(offsetof(siginfo_t, si_utime) == 0x20); > > +static_assert(offsetof(siginfo_t, si_stime) == 0x28); > > +static_assert(offsetof(siginfo_t, si_value) == 0x18); > > +static_assert(offsetof(siginfo_t, si_int) == 0x18); > > +static_assert(offsetof(siginfo_t, si_ptr) == 0x18); > > +static_assert(offsetof(siginfo_t, si_addr) == 0x10); > > +static_assert(offsetof(siginfo_t, si_trapno) == 0x18); > > +static_assert(offsetof(siginfo_t, si_addr_lsb) == 0x20); > > +static_assert(offsetof(siginfo_t, si_lower) == 0x28); > > +static_assert(offsetof(siginfo_t, si_upper) == 0x30); > > +static_assert(offsetof(siginfo_t, si_pkey) == 0x28); > > +static_assert(offsetof(siginfo_t, si_perf) == 0x20); > > +static_assert(offsetof(siginfo_t, si_band) == 0x10); > > +static_assert(offsetof(siginfo_t, si_fd) == 0x14);
