Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc

Pull sparc fixes from David Miller:

 1) Finally make perf stack backtraces stable on sparc, several problems
    (mostly due to the context in which the user copies from the stack
    are done) contributed to this.

    From Rob Gardner.

 2) Export ADI capability if the cpu supports it.

 3) Hook up userfaultfd system call.

 4) When faults happen during user copies we really have to clean up and
    restore the FPU state fully.  Also from Rob Gardner

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc:
  tty/serial: Skip 'NULL' char after console break when sysrq enabled
  sparc64: fix FP corruption in user copy functions
  sparc64: Perf should save/restore fault info
  sparc64: Ensure perf can access user stacks
  sparc64: Don't set %pil in rtrap_nmi too early
  sparc64: Add ADI capability to cpu capabilities
  tty: serial: constify sunhv_ops structs
  sparc: Hook up userfaultfd system call

6 files changed, 39 insertions, 8 deletions

diff --git a/arch/sparc/kernel/head_64.S b/arch/sparc/kernel/head_64.S
index 3d61fcae7ee3..f2d30cab5b3f 100644
--- a/arch/sparc/kernel/head_64.S
+++ b/arch/sparc/kernel/head_64.S
@@ -946,6 +946,12 @@ ENTRY(__retl_one)
 	 mov	1, %o0
 ENDPROC(__retl_one)
 
+ENTRY(__retl_one_fp)
+	VISExitHalf
+	retl
+	 mov	1, %o0
+ENDPROC(__retl_one_fp)
+
 ENTRY(__ret_one_asi)
 	wr	%g0, ASI_AIUS, %asi
 	ret
@@ -958,6 +964,13 @@ ENTRY(__retl_one_asi)
 	 mov	1, %o0
 ENDPROC(__retl_one_asi)
 
+ENTRY(__retl_one_asi_fp)
+	wr	%g0, ASI_AIUS, %asi
+	VISExitHalf
+	retl
+	 mov	1, %o0
+ENDPROC(__retl_one_asi_fp)
+
 ENTRY(__retl_o1)
 	retl
 	 mov	%o1, %o0
diff --git a/arch/sparc/kernel/perf_event.c b/arch/sparc/kernel/perf_event.c
index 3091267c5cc3..6596f66ce112 100644
--- a/arch/sparc/kernel/perf_event.c
+++ b/arch/sparc/kernel/perf_event.c
@@ -1828,11 +1828,18 @@ static void perf_callchain_user_32(struct perf_callchain_entry *entry,
 void
 perf_callchain_user(struct perf_callchain_entry *entry, struct pt_regs *regs)
 {
+	u64 saved_fault_address = current_thread_info()->fault_address;
+	u8 saved_fault_code = get_thread_fault_code();
+	mm_segment_t old_fs;
+
 	perf_callchain_store(entry, regs->tpc);
 
 	if (!current->mm)
 		return;
 
+	old_fs = get_fs();
+	set_fs(USER_DS);
+
 	flushw_user();
 
 	pagefault_disable();
@@ -1843,4 +1850,8 @@ perf_callchain_user(struct perf_callchain_entry *entry, struct pt_regs *regs)
 		perf_callchain_user_64(entry, regs);
 
 	pagefault_enable();
+
+	set_fs(old_fs);
+	set_thread_fault_code(saved_fault_code);
+	current_thread_info()->fault_address = saved_fault_address;
 }
diff --git a/arch/sparc/kernel/rtrap_64.S b/arch/sparc/kernel/rtrap_64.S
index 39f0c662f4c8..d08bdaffdbfc 100644
--- a/arch/sparc/kernel/rtrap_64.S
+++ b/arch/sparc/kernel/rtrap_64.S
@@ -73,7 +73,13 @@ rtrap_nmi:	ldx			[%sp + PTREGS_OFF + PT_V9_TSTATE], %l1
 		andn			%l1, %l4, %l1
 		srl			%l4, 20, %l4
 		ba,pt			%xcc, rtrap_no_irq_enable
-		 wrpr			%l4, %pil
+		nop
+		/* Do not actually set the %pil here.  We will do that
+		 * below after we clear PSTATE_IE in the %pstate register.
+		 * If we re-enable interrupts here, we can recurse down
+		 * the hardirq stack potentially endlessly, causing a
+		 * stack overflow.
+		 */
 
 		.align			64
 		.globl			rtrap_irq, rtrap, irqsz_patchme, rtrap_xcall
diff --git a/arch/sparc/kernel/setup_64.c b/arch/sparc/kernel/setup_64.c
index f7b261749383..f3185e2b028b 100644
--- a/arch/sparc/kernel/setup_64.c
+++ b/arch/sparc/kernel/setup_64.c
@@ -380,7 +380,8 @@ static const char *hwcaps[] = {
 	 */
 	"mul32", "div32", "fsmuld", "v8plus", "popc", "vis", "vis2",
 	"ASIBlkInit", "fmaf", "vis3", "hpc", "random", "trans", "fjfmau",
-	"ima", "cspare", "pause", "cbcond",
+	"ima", "cspare", "pause", "cbcond", NULL /*reserved for crypto */,
+	"adp",
 };
 
 static const char *crypto_hwcaps[] = {
@@ -396,7 +397,7 @@ void cpucap_info(struct seq_file *m)
 	seq_puts(m, "cpucaps\t\t: ");
 	for (i = 0; i < ARRAY_SIZE(hwcaps); i++) {
 		unsigned long bit = 1UL << i;
-		if (caps & bit) {
+		if (hwcaps[i] && (caps & bit)) {
 			seq_printf(m, "%s%s",
 				   printed ? "," : "", hwcaps[i]);
 			printed++;
@@ -450,7 +451,7 @@ static void __init report_hwcaps(unsigned long caps)
 
 	for (i = 0; i < ARRAY_SIZE(hwcaps); i++) {
 		unsigned long bit = 1UL << i;
-		if (caps & bit)
+		if (hwcaps[i] && (caps & bit))
 			report_one_hwcap(&printed, hwcaps[i]);
 	}
 	if (caps & HWCAP_SPARC_CRYPTO)
@@ -485,7 +486,7 @@ static unsigned long __init mdesc_cpu_hwcap_list(void)
 		for (i = 0; i < ARRAY_SIZE(hwcaps); i++) {
 			unsigned long bit = 1UL << i;
 
-			if (!strcmp(prop, hwcaps[i])) {
+			if (hwcaps[i] && !strcmp(prop, hwcaps[i])) {
 				caps |= bit;
 				break;
 			}
diff --git a/arch/sparc/kernel/systbls_32.S b/arch/sparc/kernel/systbls_32.S
index cc23b62b6e38..78e80293cb6d 100644
--- a/arch/sparc/kernel/systbls_32.S
+++ b/arch/sparc/kernel/systbls_32.S
@@ -87,4 +87,4 @@ sys_call_table:
 /*335*/	.long sys_syncfs, sys_sendmmsg, sys_setns, sys_process_vm_readv, sys_process_vm_writev
 /*340*/	.long sys_ni_syscall, sys_kcmp, sys_finit_module, sys_sched_setattr, sys_sched_getattr
 /*345*/	.long sys_renameat2, sys_seccomp, sys_getrandom, sys_memfd_create, sys_bpf
-/*350*/	.long sys_execveat, sys_membarrier
+/*350*/	.long sys_execveat, sys_membarrier, sys_userfaultfd
diff --git a/arch/sparc/kernel/systbls_64.S b/arch/sparc/kernel/systbls_64.S
index f229468a7479..2549c2c3ec2f 100644
--- a/arch/sparc/kernel/systbls_64.S
+++ b/arch/sparc/kernel/systbls_64.S
@@ -88,7 +88,7 @@ sys_call_table32:
 	.word sys_syncfs, compat_sys_sendmmsg, sys_setns, compat_sys_process_vm_readv, compat_sys_process_vm_writev
 /*340*/	.word sys_kern_features, sys_kcmp, sys_finit_module, sys_sched_setattr, sys_sched_getattr
 	.word sys32_renameat2, sys_seccomp, sys_getrandom, sys_memfd_create, sys_bpf
-/*350*/	.word sys32_execveat, sys_membarrier
+/*350*/	.word sys32_execveat, sys_membarrier, sys_userfaultfd
 
 #endif /* CONFIG_COMPAT */
 
@@ -168,4 +168,4 @@ sys_call_table:
 	.word sys_syncfs, sys_sendmmsg, sys_setns, sys_process_vm_readv, sys_process_vm_writev
 /*340*/	.word sys_kern_features, sys_kcmp, sys_finit_module, sys_sched_setattr, sys_sched_getattr
 	.word sys_renameat2, sys_seccomp, sys_getrandom, sys_memfd_create, sys_bpf
-/*350*/	.word sys64_execveat, sys_membarrier
+/*350*/	.word sys64_execveat, sys_membarrier, sys_userfaultfd