signal: Implement SIL_FAULT_TRAPNO
Now that si_trapno is part of the union in _si_fault and available on
all architectures, add SIL_FAULT_TRAPNO and update siginfo_layout to
return SIL_FAULT_TRAPNO when the code assumes si_trapno is valid.
There is room for future changes to reduce when si_trapno is valid but
this is all that is needed to make si_trapno and the other members of
the the union in _sigfault mutually exclusive.
Update the code that uses siginfo_layout to deal with SIL_FAULT_TRAPNO
and have the same code ignore si_trapno in in all other cases.
v1: https://lkml.kernel.org/r/m1o8dvs7s7.fsf_-_@fess.ebiederm.org
v2: https://lkml.kernel.org/r/20210505141101.11519-6-ebiederm@xmission.com
Link: https://lkml.kernel.org/r/20210517195748.8880-2-ebiederm@xmission.com
Reviewed-by: Marco Elver <elver@google.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
diff --git a/kernel/signal.c b/kernel/signal.c
index 65888ae..597594e 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -1194,6 +1194,7 @@ static inline bool has_si_pid_and_uid(struct kernel_siginfo *info)
case SIL_TIMER:
case SIL_POLL:
case SIL_FAULT:
+ case SIL_FAULT_TRAPNO:
case SIL_FAULT_MCEERR:
case SIL_FAULT_BNDERR:
case SIL_FAULT_PKUERR:
@@ -2527,6 +2528,7 @@ static void hide_si_addr_tag_bits(struct ksignal *ksig)
{
switch (siginfo_layout(ksig->sig, ksig->info.si_code)) {
case SIL_FAULT:
+ case SIL_FAULT_TRAPNO:
case SIL_FAULT_MCEERR:
case SIL_FAULT_BNDERR:
case SIL_FAULT_PKUERR:
@@ -3214,6 +3216,10 @@ enum siginfo_layout siginfo_layout(unsigned sig, int si_code)
#endif
else if ((sig == SIGTRAP) && (si_code == TRAP_PERF))
layout = SIL_PERF_EVENT;
+#ifdef __ARCH_SI_TRAPNO
+ else if (layout == SIL_FAULT)
+ layout = SIL_FAULT_TRAPNO;
+#endif
}
else if (si_code <= NSIGPOLL)
layout = SIL_POLL;
@@ -3317,30 +3323,22 @@ void copy_siginfo_to_external32(struct compat_siginfo *to,
break;
case SIL_FAULT:
to->si_addr = ptr_to_compat(from->si_addr);
-#ifdef __ARCH_SI_TRAPNO
+ break;
+ case SIL_FAULT_TRAPNO:
+ to->si_addr = ptr_to_compat(from->si_addr);
to->si_trapno = from->si_trapno;
-#endif
break;
case SIL_FAULT_MCEERR:
to->si_addr = ptr_to_compat(from->si_addr);
-#ifdef __ARCH_SI_TRAPNO
- to->si_trapno = from->si_trapno;
-#endif
to->si_addr_lsb = from->si_addr_lsb;
break;
case SIL_FAULT_BNDERR:
to->si_addr = ptr_to_compat(from->si_addr);
-#ifdef __ARCH_SI_TRAPNO
- to->si_trapno = from->si_trapno;
-#endif
to->si_lower = ptr_to_compat(from->si_lower);
to->si_upper = ptr_to_compat(from->si_upper);
break;
case SIL_FAULT_PKUERR:
to->si_addr = ptr_to_compat(from->si_addr);
-#ifdef __ARCH_SI_TRAPNO
- to->si_trapno = from->si_trapno;
-#endif
to->si_pkey = from->si_pkey;
break;
case SIL_PERF_EVENT:
@@ -3401,30 +3399,22 @@ static int post_copy_siginfo_from_user32(kernel_siginfo_t *to,
break;
case SIL_FAULT:
to->si_addr = compat_ptr(from->si_addr);
-#ifdef __ARCH_SI_TRAPNO
+ break;
+ case SIL_FAULT_TRAPNO:
+ to->si_addr = compat_ptr(from->si_addr);
to->si_trapno = from->si_trapno;
-#endif
break;
case SIL_FAULT_MCEERR:
to->si_addr = compat_ptr(from->si_addr);
-#ifdef __ARCH_SI_TRAPNO
- to->si_trapno = from->si_trapno;
-#endif
to->si_addr_lsb = from->si_addr_lsb;
break;
case SIL_FAULT_BNDERR:
to->si_addr = compat_ptr(from->si_addr);
-#ifdef __ARCH_SI_TRAPNO
- to->si_trapno = from->si_trapno;
-#endif
to->si_lower = compat_ptr(from->si_lower);
to->si_upper = compat_ptr(from->si_upper);
break;
case SIL_FAULT_PKUERR:
to->si_addr = compat_ptr(from->si_addr);
-#ifdef __ARCH_SI_TRAPNO
- to->si_trapno = from->si_trapno;
-#endif
to->si_pkey = from->si_pkey;
break;
case SIL_PERF_EVENT: