signal/sparc: si_trapno is only used with SIGILL ILL_ILLTRP

While reviewing the signal handlers on sparc it became clear that
si_trapno is only set to a non-zero value when sending SIGILL with
si_code ILL_ILLTRP.

Add force_sig_fault_trapno and send SIGILL ILL_ILLTRP with it.

Remove the define of __ARCH_SI_TRAPNO and remove the always zero
si_trapno parameter from send_sig_fault and force_sig_fault.

v1: https://lkml.kernel.org/r/m1eeers7q7.fsf_-_@fess.ebiederm.org
v2: https://lkml.kernel.org/r/20210505141101.11519-7-ebiederm@xmission.com
Link: https://lkml.kernel.org/r/87mtqnxx89.fsf_-_@disp2133Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>

arch/sparc/include/uapi/asm/siginfo.h

@@ -8,9 +8,6 @@
 
 #endif /* defined(__sparc__) && defined(__arch64__) */
 
-
-#define __ARCH_SI_TRAPNO
-
 #include <asm-generic/siginfo.h>
 
 

arch/sparc/kernel/process_64.c

@@ -518,7 +518,7 @@ void synchronize_user_stack(void)
 
 static void stack_unaligned(unsigned long sp)
 {
-	force_sig_fault(SIGBUS, BUS_ADRALN, (void __user *) sp, 0);
+	force_sig_fault(SIGBUS, BUS_ADRALN, (void __user *) sp);
 }
 
 static const char uwfault32[] = KERN_INFO \

arch/sparc/kernel/sys_sparc_32.c

@@ -151,7 +151,7 @@ sparc_breakpoint (struct pt_regs *regs)
 #ifdef DEBUG_SPARC_BREAKPOINT
         printk ("TRAP: Entering kernel PC=%x, nPC=%x\n", regs->pc, regs->npc);
 #endif
-	force_sig_fault(SIGTRAP, TRAP_BRKPT, (void __user *)regs->pc, 0);
+	force_sig_fault(SIGTRAP, TRAP_BRKPT, (void __user *)regs->pc);
 
 #ifdef DEBUG_SPARC_BREAKPOINT
 	printk ("TRAP: Returning to space: PC=%x nPC=%x\n", regs->pc, regs->npc);

arch/sparc/kernel/sys_sparc_64.c

@@ -514,7 +514,7 @@ asmlinkage void sparc_breakpoint(struct pt_regs *regs)
 #ifdef DEBUG_SPARC_BREAKPOINT
         printk ("TRAP: Entering kernel PC=%lx, nPC=%lx\n", regs->tpc, regs->tnpc);
 #endif
-	force_sig_fault(SIGTRAP, TRAP_BRKPT, (void __user *)regs->tpc, 0);
+	force_sig_fault(SIGTRAP, TRAP_BRKPT, (void __user *)regs->tpc);
 #ifdef DEBUG_SPARC_BREAKPOINT
 	printk ("TRAP: Returning to space: PC=%lx nPC=%lx\n", regs->tpc, regs->tnpc);
 #endif

arch/sparc/kernel/traps_32.c

@@ -102,7 +102,7 @@ void do_hw_interrupt(struct pt_regs *regs, unsigned long type)
 	if(regs->psr & PSR_PS)
 		die_if_kernel("Kernel bad trap", regs);
 
-	force_sig_fault(SIGILL, ILL_ILLTRP,
+	force_sig_fault_trapno(SIGILL, ILL_ILLTRP,
 			       (void __user *)regs->pc, type - 0x80);
 }
 
@@ -116,7 +116,7 @@ void do_illegal_instruction(struct pt_regs *regs, unsigned long pc, unsigned lon
 	       regs->pc, *(unsigned long *)regs->pc);
 #endif
 
-	send_sig_fault(SIGILL, ILL_ILLOPC, (void __user *)pc, 0, current);
+	send_sig_fault(SIGILL, ILL_ILLOPC, (void __user *)pc, current);
 }
 
 void do_priv_instruction(struct pt_regs *regs, unsigned long pc, unsigned long npc,
@@ -124,7 +124,7 @@ void do_priv_instruction(struct pt_regs *regs, unsigned long pc, unsigned long n
 {
 	if(psr & PSR_PS)
 		die_if_kernel("Penguin instruction from Penguin mode??!?!", regs);
-	send_sig_fault(SIGILL, ILL_PRVOPC, (void __user *)pc, 0, current);
+	send_sig_fault(SIGILL, ILL_PRVOPC, (void __user *)pc, current);
 }
 
 /* XXX User may want to be allowed to do this. XXX */
@@ -145,7 +145,7 @@ void do_memaccess_unaligned(struct pt_regs *regs, unsigned long pc, unsigned lon
 #endif
 	send_sig_fault(SIGBUS, BUS_ADRALN,
 		       /* FIXME: Should dig out mna address */ (void *)0,
-		       0, current);
+		       current);
 }
 
 static unsigned long init_fsr = 0x0UL;
@@ -291,7 +291,7 @@ void do_fpe_trap(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 		else if (fsr & 0x01)
 			code = FPE_FLTRES;
 	}
-	send_sig_fault(SIGFPE, code, (void __user *)pc, 0, fpt);
+	send_sig_fault(SIGFPE, code, (void __user *)pc, fpt);
 #ifndef CONFIG_SMP
 	last_task_used_math = NULL;
 #endif
@@ -305,7 +305,7 @@ void handle_tag_overflow(struct pt_regs *regs, unsigned long pc, unsigned long n
 {
 	if(psr & PSR_PS)
 		die_if_kernel("Penguin overflow trap from kernel mode", regs);
-	send_sig_fault(SIGEMT, EMT_TAGOVF, (void __user *)pc, 0, current);
+	send_sig_fault(SIGEMT, EMT_TAGOVF, (void __user *)pc, current);
 }
 
 void handle_watchpoint(struct pt_regs *regs, unsigned long pc, unsigned long npc,
@@ -327,13 +327,13 @@ void handle_reg_access(struct pt_regs *regs, unsigned long pc, unsigned long npc
 	printk("Register Access Exception at PC %08lx NPC %08lx PSR %08lx\n",
 	       pc, npc, psr);
 #endif
-	force_sig_fault(SIGBUS, BUS_OBJERR, (void __user *)pc, 0);
+	force_sig_fault(SIGBUS, BUS_OBJERR, (void __user *)pc);
 }
 
 void handle_cp_disabled(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 			unsigned long psr)
 {
-	send_sig_fault(SIGILL, ILL_COPROC, (void __user *)pc, 0, current);
+	send_sig_fault(SIGILL, ILL_COPROC, (void __user *)pc, current);
 }
 
 void handle_cp_exception(struct pt_regs *regs, unsigned long pc, unsigned long npc,
@@ -343,13 +343,13 @@ void handle_cp_exception(struct pt_regs *regs, unsigned long pc, unsigned long n
 	printk("Co-Processor Exception at PC %08lx NPC %08lx PSR %08lx\n",
 	       pc, npc, psr);
 #endif
-	send_sig_fault(SIGILL, ILL_COPROC, (void __user *)pc, 0, current);
+	send_sig_fault(SIGILL, ILL_COPROC, (void __user *)pc, current);
 }
 
 void handle_hw_divzero(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 		       unsigned long psr)
 {
-	send_sig_fault(SIGFPE, FPE_INTDIV, (void __user *)pc, 0, current);
+	send_sig_fault(SIGFPE, FPE_INTDIV, (void __user *)pc, current);
 }
 
 #ifdef CONFIG_DEBUG_BUGVERBOSE

arch/sparc/kernel/traps_64.c

@@ -107,7 +107,7 @@ void bad_trap(struct pt_regs *regs, long lvl)
 		regs->tpc &= 0xffffffff;
 		regs->tnpc &= 0xffffffff;
 	}
-	force_sig_fault(SIGILL, ILL_ILLTRP,
+	force_sig_fault_trapno(SIGILL, ILL_ILLTRP,
 			       (void __user *)regs->tpc, lvl);
 }
 
@@ -201,8 +201,7 @@ void spitfire_insn_access_exception(struct pt_regs *regs, unsigned long sfsr, un
 		regs->tpc &= 0xffffffff;
 		regs->tnpc &= 0xffffffff;
 	}
-	force_sig_fault(SIGSEGV, SEGV_MAPERR,
-			(void __user *)regs->tpc, 0);
+	force_sig_fault(SIGSEGV, SEGV_MAPERR, (void __user *)regs->tpc);
 out:
 	exception_exit(prev_state);
 }
@@ -237,7 +236,7 @@ void sun4v_insn_access_exception(struct pt_regs *regs, unsigned long addr, unsig
 		regs->tpc &= 0xffffffff;
 		regs->tnpc &= 0xffffffff;
 	}
-	force_sig_fault(SIGSEGV, SEGV_MAPERR, (void __user *) addr, 0);
+	force_sig_fault(SIGSEGV, SEGV_MAPERR, (void __user *) addr);
 }
 
 void sun4v_insn_access_exception_tl1(struct pt_regs *regs, unsigned long addr, unsigned long type_ctx)
@@ -321,7 +320,7 @@ void spitfire_data_access_exception(struct pt_regs *regs, unsigned long sfsr, un
 	if (is_no_fault_exception(regs))
 		return;
 
-	force_sig_fault(SIGSEGV, SEGV_MAPERR, (void __user *)sfar, 0);
+	force_sig_fault(SIGSEGV, SEGV_MAPERR, (void __user *)sfar);
 out:
 	exception_exit(prev_state);
 }
@@ -385,13 +384,13 @@ void sun4v_data_access_exception(struct pt_regs *regs, unsigned long addr, unsig
 	 */
 	switch (type) {
 	case HV_FAULT_TYPE_INV_ASI:
-		force_sig_fault(SIGILL, ILL_ILLADR, (void __user *)addr, 0);
+		force_sig_fault(SIGILL, ILL_ILLADR, (void __user *)addr);
 		break;
 	case HV_FAULT_TYPE_MCD_DIS:
-		force_sig_fault(SIGSEGV, SEGV_ACCADI, (void __user *)addr, 0);
+		force_sig_fault(SIGSEGV, SEGV_ACCADI, (void __user *)addr);
 		break;
 	default:
-		force_sig_fault(SIGSEGV, SEGV_MAPERR, (void __user *)addr, 0);
+		force_sig_fault(SIGSEGV, SEGV_MAPERR, (void __user *)addr);
 		break;
 	}
 }
@@ -568,7 +567,7 @@ static void spitfire_ue_log(unsigned long afsr, unsigned long afar, unsigned lon
 		regs->tpc &= 0xffffffff;
 		regs->tnpc &= 0xffffffff;
 	}
-	force_sig_fault(SIGBUS, BUS_OBJERR, (void *)0, 0);
+	force_sig_fault(SIGBUS, BUS_OBJERR, (void *)0);
 }
 
 void spitfire_access_error(struct pt_regs *regs, unsigned long status_encoded, unsigned long afar)
@@ -2069,8 +2068,7 @@ void do_mcd_err(struct pt_regs *regs, struct sun4v_error_entry ent)
 	/* Send SIGSEGV to the userspace process with the right signal
 	 * code
 	 */
-	force_sig_fault(SIGSEGV, SEGV_ADIDERR, (void __user *)ent.err_raddr,
-			0);
+	force_sig_fault(SIGSEGV, SEGV_ADIDERR, (void __user *)ent.err_raddr);
 }
 
 /* We run with %pil set to PIL_NORMAL_MAX and PSTATE_IE enabled in %pstate.
@@ -2184,7 +2182,7 @@ bool sun4v_nonresum_error_user_handled(struct pt_regs *regs,
 	}
 	if (attrs & SUN4V_ERR_ATTRS_PIO) {
 		force_sig_fault(SIGBUS, BUS_ADRERR,
-				(void __user *)sun4v_get_vaddr(regs), 0);
+				(void __user *)sun4v_get_vaddr(regs));
 		return true;
 	}
 
@@ -2340,8 +2338,7 @@ static void do_fpe_common(struct pt_regs *regs)
 			else if (fsr & 0x01)
 				code = FPE_FLTRES;
 		}
-		force_sig_fault(SIGFPE, code,
-				(void __user *)regs->tpc, 0);
+		force_sig_fault(SIGFPE, code, (void __user *)regs->tpc);
 	}
 }
 
@@ -2395,8 +2392,7 @@ void do_tof(struct pt_regs *regs)
 		regs->tpc &= 0xffffffff;
 		regs->tnpc &= 0xffffffff;
 	}
-	force_sig_fault(SIGEMT, EMT_TAGOVF,
-			(void __user *)regs->tpc, 0);
+	force_sig_fault(SIGEMT, EMT_TAGOVF, (void __user *)regs->tpc);
 out:
 	exception_exit(prev_state);
 }
@@ -2415,8 +2411,7 @@ void do_div0(struct pt_regs *regs)
 		regs->tpc &= 0xffffffff;
 		regs->tnpc &= 0xffffffff;
 	}
-	force_sig_fault(SIGFPE, FPE_INTDIV,
-			(void __user *)regs->tpc, 0);
+	force_sig_fault(SIGFPE, FPE_INTDIV, (void __user *)regs->tpc);
 out:
 	exception_exit(prev_state);
 }
@@ -2612,7 +2607,7 @@ void do_illegal_instruction(struct pt_regs *regs)
 			}
 		}
 	}
-	force_sig_fault(SIGILL, ILL_ILLOPC, (void __user *)pc, 0);
+	force_sig_fault(SIGILL, ILL_ILLOPC, (void __user *)pc);
 out:
 	exception_exit(prev_state);
 }
@@ -2632,7 +2627,7 @@ void mem_address_unaligned(struct pt_regs *regs, unsigned long sfar, unsigned lo
 	if (is_no_fault_exception(regs))
 		return;
 
-	force_sig_fault(SIGBUS, BUS_ADRALN, (void __user *)sfar, 0);
+	force_sig_fault(SIGBUS, BUS_ADRALN, (void __user *)sfar);
 out:
 	exception_exit(prev_state);
 }
@@ -2650,7 +2645,7 @@ void sun4v_do_mna(struct pt_regs *regs, unsigned long addr, unsigned long type_c
 	if (is_no_fault_exception(regs))
 		return;
 
-	force_sig_fault(SIGBUS, BUS_ADRALN, (void __user *) addr, 0);
+	force_sig_fault(SIGBUS, BUS_ADRALN, (void __user *) addr);
 }
 
 /* sun4v_mem_corrupt_detect_precise() - Handle precise exception on an ADI
@@ -2697,7 +2692,7 @@ void sun4v_mem_corrupt_detect_precise(struct pt_regs *regs, unsigned long addr,
 		regs->tpc &= 0xffffffff;
 		regs->tnpc &= 0xffffffff;
 	}
-	force_sig_fault(SIGSEGV, SEGV_ADIPERR, (void __user *)addr, 0);
+	force_sig_fault(SIGSEGV, SEGV_ADIPERR, (void __user *)addr);
 }
 
 void do_privop(struct pt_regs *regs)
@@ -2712,8 +2707,7 @@ void do_privop(struct pt_regs *regs)
 		regs->tpc &= 0xffffffff;
 		regs->tnpc &= 0xffffffff;
 	}
-	force_sig_fault(SIGILL, ILL_PRVOPC,
-			(void __user *)regs->tpc, 0);
+	force_sig_fault(SIGILL, ILL_PRVOPC, (void __user *)regs->tpc);
 out:
 	exception_exit(prev_state);
 }

arch/sparc/kernel/unaligned_32.c

@@ -278,5 +278,5 @@ asmlinkage void user_unaligned_trap(struct pt_regs *regs, unsigned int insn)
 {
 	send_sig_fault(SIGBUS, BUS_ADRALN,
 		       (void __user *)safe_compute_effective_address(regs, insn),
-		       0, current);
+		       current);
 }

arch/sparc/mm/fault_32.c

@@ -83,7 +83,7 @@ static void __do_fault_siginfo(int code, int sig, struct pt_regs *regs,
 		show_signal_msg(regs, sig, code,
 				addr, current);
 
-	force_sig_fault(sig, code, (void __user *) addr, 0);
+	force_sig_fault(sig, code, (void __user *) addr);
 }
 
 static unsigned long compute_si_addr(struct pt_regs *regs, int text_fault)

arch/sparc/mm/fault_64.c

@@ -176,7 +176,7 @@ static void do_fault_siginfo(int code, int sig, struct pt_regs *regs,
 	if (unlikely(show_unhandled_signals))
 		show_signal_msg(regs, sig, code, addr, current);
 
-	force_sig_fault(sig, code, (void __user *) addr, 0);
+	force_sig_fault(sig, code, (void __user *) addr);
 }
 
 static unsigned int get_fault_insn(struct pt_regs *regs, unsigned int insn)

include/linux/sched/signal.h

@@ -329,6 +329,7 @@ int force_sig_pkuerr(void __user *addr, u32 pkey);
 int force_sig_perf(void __user *addr, u32 type, u64 sig_data);
 
 int force_sig_ptrace_errno_trap(int errno, void __user *addr);
+int force_sig_fault_trapno(int sig, int code, void __user *addr, int trapno);
 
 extern int send_sig_info(int, struct kernel_siginfo *, struct task_struct *);
 extern void force_sigsegv(int sig);

kernel/signal.c

@@ -1808,6 +1808,22 @@ 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);
+}
+
 int kill_pgrp(struct pid *pid, int sig, int priv)
 {
 	int ret;
@@ -3243,6 +3259,9 @@ enum siginfo_layout siginfo_layout(unsigned sig, int si_code)
 #endif
 			else if ((sig == SIGTRAP) && (si_code == TRAP_PERF))
 				layout = SIL_PERF_EVENT;
+			else if (IS_ENABLED(CONFIG_SPARC) &&
+				 (sig == SIGILL) && (si_code == ILL_ILLTRP))
+				layout = SIL_FAULT_TRAPNO;
 #ifdef __ARCH_SI_TRAPNO
 			else if (layout == SIL_FAULT)
 				layout = SIL_FAULT_TRAPNO;