Merge branch 'siginfo-si_trapno-for-v5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace

Pull siginfo si_trapno updates from Eric Biederman:
 "The full set of si_trapno changes was not appropriate as a fix for the
  newly added SIGTRAP TRAP_PERF, and so I postponed the rest of the
  related cleanups.

  This is the rest of the cleanups for si_trapno that reduces it from
  being a really weird arch special case that is expect to be always
  present (but isn't) on the architectures that support it to being yet
  another field in the _sigfault union of struct siginfo.

  The changes have been reviewed and marinated in linux-next. With the
  removal of this awkward special case new code (like SIGTRAP TRAP_PERF)
  that works across architectures should be easier to write and
  maintain"

* 'siginfo-si_trapno-for-v5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
  signal: Rename SIL_PERF_EVENT SIL_FAULT_PERF_EVENT for consistency
  signal: Verify the alignment and size of siginfo_t
  signal: Remove the generic __ARCH_SI_TRAPNO support
  signal/alpha: si_trapno is only used with SIGFPE and SIGTRAP TRAP_UNK
  signal/sparc: si_trapno is only used with SIGILL ILL_ILLTRP
  arm64: Add compile-time asserts for siginfo_t offsets
  arm: Add compile-time asserts for siginfo_t offsets
  sparc64: Add compile-time asserts for siginfo_t offsets

1 files changed, 44 insertions, 18 deletions

diff --git a/kernel/signal.c b/kernel/signal.c
index 52b6abec0ff8..65a54118ac9e 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -1213,7 +1213,7 @@ static inline bool has_si_pid_and_uid(struct kernel_siginfo *info)
 	case SIL_FAULT_MCEERR:
 	case SIL_FAULT_BNDERR:
 	case SIL_FAULT_PKUERR:
-	case SIL_PERF_EVENT:
+	case SIL_FAULT_PERF_EVENT:
 	case SIL_SYS:
 		ret = false;
 		break;
@@ -1681,7 +1681,6 @@ void force_sigsegv(int sig)
 }
 
 int force_sig_fault_to_task(int sig, int code, void __user *addr
-	___ARCH_SI_TRAPNO(int trapno)
 	___ARCH_SI_IA64(int imm, unsigned int flags, unsigned long isr)
 	, struct task_struct *t)
 {
@@ -1692,9 +1691,6 @@ int force_sig_fault_to_task(int sig, int code, void __user *addr
 	info.si_errno = 0;
 	info.si_code  = code;
 	info.si_addr  = addr;
-#ifdef __ARCH_SI_TRAPNO
-	info.si_trapno = trapno;
-#endif
 #ifdef __ia64__
 	info.si_imm = imm;
 	info.si_flags = flags;
@@ -1704,16 +1700,13 @@ int force_sig_fault_to_task(int sig, int code, void __user *addr
 }
 
 int force_sig_fault(int sig, int code, void __user *addr
-	___ARCH_SI_TRAPNO(int trapno)
 	___ARCH_SI_IA64(int imm, unsigned int flags, unsigned long isr))
 {
 	return force_sig_fault_to_task(sig, code, addr
-				       ___ARCH_SI_TRAPNO(trapno)
 				       ___ARCH_SI_IA64(imm, flags, isr), current);
 }
 
 int send_sig_fault(int sig, int code, void __user *addr
-	___ARCH_SI_TRAPNO(int trapno)
 	___ARCH_SI_IA64(int imm, unsigned int flags, unsigned long isr)
 	, struct task_struct *t)
 {
@@ -1724,9 +1717,6 @@ int send_sig_fault(int sig, int code, void __user *addr
 	info.si_errno = 0;
 	info.si_code  = code;
 	info.si_addr  = addr;
-#ifdef __ARCH_SI_TRAPNO
-	info.si_trapno = trapno;
-#endif
 #ifdef __ia64__
 	info.si_imm = imm;
 	info.si_flags = flags;
@@ -1823,6 +1813,39 @@ int force_sig_ptrace_errno_trap(int errno, void __user *addr)
 	return force_sig_info(&info);
 }
 
+/* For the rare architectures that include trap information using
+ * si_trapno.
+ */
+int force_sig_fault_trapno(int sig, int code, void __user *addr, int trapno)
+{
+	struct kernel_siginfo info;
+
+	clear_siginfo(&info);
+	info.si_signo = sig;
+	info.si_errno = 0;
+	info.si_code  = code;
+	info.si_addr  = addr;
+	info.si_trapno = trapno;
+	return force_sig_info(&info);
+}
+
+/* For the rare architectures that include trap information using
+ * si_trapno.
+ */
+int send_sig_fault_trapno(int sig, int code, void __user *addr, int trapno,
+			  struct task_struct *t)
+{
+	struct kernel_siginfo info;
+
+	clear_siginfo(&info);
+	info.si_signo = sig;
+	info.si_errno = 0;
+	info.si_code  = code;
+	info.si_addr  = addr;
+	info.si_trapno = trapno;
+	return send_sig_info(info.si_signo, &info, t);
+}
+
 int kill_pgrp(struct pid *pid, int sig, int priv)
 {
 	int ret;
@@ -2572,7 +2595,7 @@ static void hide_si_addr_tag_bits(struct ksignal *ksig)
 	case SIL_FAULT_MCEERR:
 	case SIL_FAULT_BNDERR:
 	case SIL_FAULT_PKUERR:
-	case SIL_PERF_EVENT:
+	case SIL_FAULT_PERF_EVENT:
 		ksig->info.si_addr = arch_untagged_si_addr(
 			ksig->info.si_addr, ksig->sig, ksig->info.si_code);
 		break;
@@ -3257,11 +3280,14 @@ enum siginfo_layout siginfo_layout(unsigned sig, int si_code)
 				layout = SIL_FAULT_PKUERR;
 #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_PERF_EVENT;
+			else if (IS_ENABLED(CONFIG_SPARC) &&
+				 (sig == SIGILL) && (si_code == ILL_ILLTRP))
+				layout = SIL_FAULT_TRAPNO;
+			else if (IS_ENABLED(CONFIG_ALPHA) &&
+				 ((sig == SIGFPE) ||
+				  ((sig == SIGTRAP) && (si_code == TRAP_UNK))))
 				layout = SIL_FAULT_TRAPNO;
-#endif
 		}
 		else if (si_code <= NSIGPOLL)
 			layout = SIL_POLL;
@@ -3383,7 +3409,7 @@ void copy_siginfo_to_external32(struct compat_siginfo *to,
 		to->si_addr = ptr_to_compat(from->si_addr);
 		to->si_pkey = from->si_pkey;
 		break;
-	case SIL_PERF_EVENT:
+	case SIL_FAULT_PERF_EVENT:
 		to->si_addr = ptr_to_compat(from->si_addr);
 		to->si_perf_data = from->si_perf_data;
 		to->si_perf_type = from->si_perf_type;
@@ -3460,7 +3486,7 @@ static int post_copy_siginfo_from_user32(kernel_siginfo_t *to,
 		to->si_addr = compat_ptr(from->si_addr);
 		to->si_pkey = from->si_pkey;
 		break;
-	case SIL_PERF_EVENT:
+	case SIL_FAULT_PERF_EVENT:
 		to->si_addr = compat_ptr(from->si_addr);
 		to->si_perf_data = from->si_perf_data;
 		to->si_perf_type = from->si_perf_type;