Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 updates from Will Deacon:
 "The highlights this time are support for dynamically enabling and
  disabling Clang's Shadow Call Stack at boot and a long-awaited
  optimisation to the way in which we handle the SVE register state on
  system call entry to avoid taking unnecessary traps from userspace.

  Summary:

  ACPI:
   - Enable FPDT support for boot-time profiling
   - Fix CPU PMU probing to work better with PREEMPT_RT
   - Update SMMUv3 MSI DeviceID parsing to latest IORT spec
   - APMT support for probing Arm CoreSight PMU devices

  CPU features:
   - Advertise new SVE instructions (v2.1)
   - Advertise range prefetch instruction
   - Advertise CSSC ("Common Short Sequence Compression") scalar
     instructions, adding things like min, max, abs, popcount
   - Enable DIT (Data Independent Timing) when running in the kernel
   - More conversion of system register fields over to the generated
     header

  CPU misfeatures:
   - Workaround for Cortex-A715 erratum #2645198

  Dynamic SCS:
   - Support for dynamic shadow call stacks to allow switching at
     runtime between Clang's SCS implementation and the CPU's pointer
     authentication feature when it is supported (complete with scary
     DWARF parser!)

  Tracing and debug:
   - Remove static ftrace in favour of, err, dynamic ftrace!
   - Seperate 'struct ftrace_regs' from 'struct pt_regs' in core ftrace
     and existing arch code
   - Introduce and implement FTRACE_WITH_ARGS on arm64 to replace the
     old FTRACE_WITH_REGS
   - Extend 'crashkernel=' parameter with default value and fallback to
     placement above 4G physical if initial (low) allocation fails

  SVE:
   - Optimisation to avoid disabling SVE unconditionally on syscall
     entry and just zeroing the non-shared state on return instead

  Exceptions:
   - Rework of undefined instruction handling to avoid serialisation on
     global lock (this includes emulation of user accesses to the ID
     registers)

  Perf and PMU:
   - Support for TLP filters in Hisilicon's PCIe PMU device
   - Support for the DDR PMU present in Amlogic Meson G12 SoCs
   - Support for the terribly-named "CoreSight PMU" architecture from
     Arm (and Nvidia's implementation of said architecture)

  Misc:
   - Tighten up our boot protocol for systems with memory above 52 bits
     physical
   - Const-ify static keys to satisty jump label asm constraints
   - Trivial FFA driver cleanups in preparation for v1.1 support
   - Export the kernel_neon_* APIs as GPL symbols
   - Harden our instruction generation routines against instrumentation
   - A bunch of robustness improvements to our arch-specific selftests
   - Minor cleanups and fixes all over (kbuild, kprobes, kfence, PMU, ...)"

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (151 commits)
  arm64: kprobes: Return DBG_HOOK_ERROR if kprobes can not handle a BRK
  arm64: kprobes: Let arch do_page_fault() fix up page fault in user handler
  arm64: Prohibit instrumentation on arch_stack_walk()
  arm64:uprobe fix the uprobe SWBP_INSN in big-endian
  arm64: alternatives: add __init/__initconst to some functions/variables
  arm_pmu: Drop redundant armpmu->map_event() in armpmu_event_init()
  kselftest/arm64: Allow epoll_wait() to return more than one result
  kselftest/arm64: Don't drain output while spawning children
  kselftest/arm64: Hold fp-stress children until they're all spawned
  arm64/sysreg: Remove duplicate definitions from asm/sysreg.h
  arm64/sysreg: Convert ID_DFR1_EL1 to automatic generation
  arm64/sysreg: Convert ID_DFR0_EL1 to automatic generation
  arm64/sysreg: Convert ID_AFR0_EL1 to automatic generation
  arm64/sysreg: Convert ID_MMFR5_EL1 to automatic generation
  arm64/sysreg: Convert MVFR2_EL1 to automatic generation
  arm64/sysreg: Convert MVFR1_EL1 to automatic generation
  arm64/sysreg: Convert MVFR0_EL1 to automatic generation
  arm64/sysreg: Convert ID_PFR2_EL1 to automatic generation
  arm64/sysreg: Convert ID_PFR1_EL1 to automatic generation
  arm64/sysreg: Convert ID_PFR0_EL1 to automatic generation
  ...

7 files changed, 154 insertions, 45 deletions

diff --git a/tools/testing/selftests/arm64/abi/hwcap.c b/tools/testing/selftests/arm64/abi/hwcap.c
index 9f1a7b5c6193..9f255bc5f31c 100644
--- a/tools/testing/selftests/arm64/abi/hwcap.c
+++ b/tools/testing/selftests/arm64/abi/hwcap.c
@@ -33,6 +33,12 @@
  */
 typedef void (*sigill_fn)(void);
 
+static void cssc_sigill(void)
+{
+	/* CNT x0, x0 */
+	asm volatile(".inst 0xdac01c00" : : : "x0");
+}
+
 static void rng_sigill(void)
 {
 	asm volatile("mrs x0, S3_3_C2_C4_0" : : : "x0");
@@ -56,6 +62,12 @@ static void sve2_sigill(void)
 	asm volatile(".inst 0x4408A000" : : : "z0");
 }
 
+static void sve2p1_sigill(void)
+{
+	/* BFADD Z0.H, Z0.H, Z0.H */
+	asm volatile(".inst 0x65000000" : : : "z0");
+}
+
 static void sveaes_sigill(void)
 {
 	/* AESD z0.b, z0.b, z0.b */
@@ -119,6 +131,13 @@ static const struct hwcap_data {
 	bool sigill_reliable;
 } hwcaps[] = {
 	{
+		.name = "CSSC",
+		.at_hwcap = AT_HWCAP2,
+		.hwcap_bit = HWCAP2_CSSC,
+		.cpuinfo = "cssc",
+		.sigill_fn = cssc_sigill,
+	},
+	{
 		.name = "RNG",
 		.at_hwcap = AT_HWCAP2,
 		.hwcap_bit = HWCAP2_RNG,
@@ -126,6 +145,12 @@ static const struct hwcap_data {
 		.sigill_fn = rng_sigill,
 	},
 	{
+		.name = "RPRFM",
+		.at_hwcap = AT_HWCAP2,
+		.hwcap_bit = HWCAP2_RPRFM,
+		.cpuinfo = "rprfm",
+	},
+	{
 		.name = "SME",
 		.at_hwcap = AT_HWCAP2,
 		.hwcap_bit = HWCAP2_SME,
@@ -149,6 +174,13 @@ static const struct hwcap_data {
 		.sigill_fn = sve2_sigill,
 	},
 	{
+		.name = "SVE 2.1",
+		.at_hwcap = AT_HWCAP2,
+		.hwcap_bit = HWCAP2_SVE2P1,
+		.cpuinfo = "sve2p1",
+		.sigill_fn = sve2p1_sigill,
+	},
+	{
 		.name = "SVE AES",
 		.at_hwcap = AT_HWCAP2,
 		.hwcap_bit = HWCAP2_SVEAES,
diff --git a/tools/testing/selftests/arm64/abi/syscall-abi-asm.S b/tools/testing/selftests/arm64/abi/syscall-abi-asm.S
index b523c21c2278..acd5e9f3bc0b 100644
--- a/tools/testing/selftests/arm64/abi/syscall-abi-asm.S
+++ b/tools/testing/selftests/arm64/abi/syscall-abi-asm.S
@@ -153,7 +153,7 @@ do_syscall:
 	// Only set a non-zero FFR, test patterns must be zero since the
 	// syscall should clear it - this lets us handle FA64.
 	ldr	x2, =ffr_in
-	ldr	p0, [x2, #0]
+	ldr	p0, [x2]
 	ldr	x2, [x2, #0]
 	cbz	x2, 2f
 	wrffr	p0.b
@@ -298,7 +298,7 @@ do_syscall:
 	cbz	x2, 1f
 	ldr	x2, =ffr_out
 	rdffr	p0.b
-	str	p0, [x2, #0]
+	str	p0, [x2]
 1:
 
 	// Restore callee saved registers x19-x30
diff --git a/tools/testing/selftests/arm64/fp/fp-stress.c b/tools/testing/selftests/arm64/fp/fp-stress.c
index 4e62a9199f97..f8b2f41aac36 100644
--- a/tools/testing/selftests/arm64/fp/fp-stress.c
+++ b/tools/testing/selftests/arm64/fp/fp-stress.c
@@ -39,10 +39,12 @@ struct child_data {
 
 static int epoll_fd;
 static struct child_data *children;
+static struct epoll_event *evs;
+static int tests;
 static int num_children;
 static bool terminate;
 
-static void drain_output(bool flush);
+static int startup_pipe[2];
 
 static int num_processors(void)
 {
@@ -82,12 +84,36 @@ static void child_start(struct child_data *child, const char *program)
 		}
 
 		/*
+		 * Duplicate the read side of the startup pipe to
+		 * FD 3 so we can close everything else.
+		 */
+		ret = dup2(startup_pipe[0], 3);
+		if (ret == -1) {
+			fprintf(stderr, "dup2() %d\n", errno);
+			exit(EXIT_FAILURE);
+		}
+
+		/*
 		 * Very dumb mechanism to clean open FDs other than
 		 * stdio. We don't want O_CLOEXEC for the pipes...
 		 */
-		for (i = 3; i < 8192; i++)
+		for (i = 4; i < 8192; i++)
 			close(i);
 
+		/*
+		 * Read from the startup pipe, there should be no data
+		 * and we should block until it is closed.  We just
+		 * carry on on error since this isn't super critical.
+		 */
+		ret = read(3, &i, sizeof(i));
+		if (ret < 0)
+			fprintf(stderr, "read(startp pipe) failed: %s (%d)\n",
+				strerror(errno), errno);
+		if (ret > 0)
+			fprintf(stderr, "%d bytes of data on startup pipe\n",
+				ret);
+		close(3);
+
 		ret = execl(program, program, NULL);
 		fprintf(stderr, "execl(%s) failed: %d (%s)\n",
 			program, errno, strerror(errno));
@@ -112,12 +138,6 @@ static void child_start(struct child_data *child, const char *program)
 			ksft_exit_fail_msg("%s EPOLL_CTL_ADD failed: %s (%d)\n",
 					   child->name, strerror(errno), errno);
 		}
-
-		/*
-		 * Keep output flowing during child startup so logs
-		 * are more timely, can help debugging.
-		 */
-		drain_output(false);
 	}
 }
 
@@ -290,12 +310,12 @@ static void start_fpsimd(struct child_data *child, int cpu, int copy)
 {
 	int ret;
 
-	child_start(child, "./fpsimd-test");
-
 	ret = asprintf(&child->name, "FPSIMD-%d-%d", cpu, copy);
 	if (ret == -1)
 		ksft_exit_fail_msg("asprintf() failed\n");
 
+	child_start(child, "./fpsimd-test");
+
 	ksft_print_msg("Started %s\n", child->name);
 }
 
@@ -307,12 +327,12 @@ static void start_sve(struct child_data *child, int vl, int cpu)
 	if (ret < 0)
 		ksft_exit_fail_msg("Failed to set SVE VL %d\n", vl);
 
-	child_start(child, "./sve-test");
-
 	ret = asprintf(&child->name, "SVE-VL-%d-%d", vl, cpu);
 	if (ret == -1)
 		ksft_exit_fail_msg("asprintf() failed\n");
 
+	child_start(child, "./sve-test");
+
 	ksft_print_msg("Started %s\n", child->name);
 }
 
@@ -320,16 +340,16 @@ static void start_ssve(struct child_data *child, int vl, int cpu)
 {
 	int ret;
 
+	ret = asprintf(&child->name, "SSVE-VL-%d-%d", vl, cpu);
+	if (ret == -1)
+		ksft_exit_fail_msg("asprintf() failed\n");
+
 	ret = prctl(PR_SME_SET_VL, vl | PR_SME_VL_INHERIT);
 	if (ret < 0)
 		ksft_exit_fail_msg("Failed to set SME VL %d\n", ret);
 
 	child_start(child, "./ssve-test");
 
-	ret = asprintf(&child->name, "SSVE-VL-%d-%d", vl, cpu);
-	if (ret == -1)
-		ksft_exit_fail_msg("asprintf() failed\n");
-
 	ksft_print_msg("Started %s\n", child->name);
 }
 
@@ -341,12 +361,12 @@ static void start_za(struct child_data *child, int vl, int cpu)
 	if (ret < 0)
 		ksft_exit_fail_msg("Failed to set SME VL %d\n", ret);
 
-	child_start(child, "./za-test");
-
 	ret = asprintf(&child->name, "ZA-VL-%d-%d", vl, cpu);
 	if (ret == -1)
 		ksft_exit_fail_msg("asprintf() failed\n");
 
+	child_start(child, "./za-test");
+
 	ksft_print_msg("Started %s\n", child->name);
 }
 
@@ -375,11 +395,11 @@ static void probe_vls(int vls[], int *vl_count, int set_vl)
 /* Handle any pending output without blocking */
 static void drain_output(bool flush)
 {
-	struct epoll_event ev;
 	int ret = 1;
+	int i;
 
 	while (ret > 0) {
-		ret = epoll_wait(epoll_fd, &ev, 1, 0);
+		ret = epoll_wait(epoll_fd, evs, tests, 0);
 		if (ret < 0) {
 			if (errno == EINTR)
 				continue;
@@ -387,8 +407,8 @@ static void drain_output(bool flush)
 				       strerror(errno), errno);
 		}
 
-		if (ret == 1)
-			child_output(ev.data.ptr, ev.events, flush);
+		for (i = 0; i < ret; i++)
+			child_output(evs[i].data.ptr, evs[i].events, flush);
 	}
 }
 
@@ -401,10 +421,11 @@ int main(int argc, char **argv)
 {
 	int ret;
 	int timeout = 10;
-	int cpus, tests, i, j, c;
+	int cpus, i, j, c;
 	int sve_vl_count, sme_vl_count, fpsimd_per_cpu;
+	bool all_children_started = false;
+	int seen_children;
 	int sve_vls[MAX_VLS], sme_vls[MAX_VLS];
-	struct epoll_event ev;
 	struct sigaction sa;
 
 	while ((c = getopt_long(argc, argv, "t:", options, NULL)) != -1) {
@@ -465,6 +486,12 @@ int main(int argc, char **argv)
 				   strerror(errno), ret);
 	epoll_fd = ret;
 
+	/* Create a pipe which children will block on before execing */
+	ret = pipe(startup_pipe);
+	if (ret != 0)
+		ksft_exit_fail_msg("Failed to create startup pipe: %s (%d)\n",
+				   strerror(errno), errno);
+
 	/* Get signal handers ready before we start any children */
 	memset(&sa, 0, sizeof(sa));
 	sa.sa_sigaction = handle_exit_signal;
@@ -484,6 +511,11 @@ int main(int argc, char **argv)
 		ksft_print_msg("Failed to install SIGCHLD handler: %s (%d)\n",
 			       strerror(errno), errno);
 
+	evs = calloc(tests, sizeof(*evs));
+	if (!evs)
+		ksft_exit_fail_msg("Failed to allocated %d epoll events\n",
+				   tests);
+
 	for (i = 0; i < cpus; i++) {
 		for (j = 0; j < fpsimd_per_cpu; j++)
 			start_fpsimd(&children[num_children++], i, j);
@@ -497,6 +529,13 @@ int main(int argc, char **argv)
 		}
 	}
 
+	/*
+	 * All children started, close the startup pipe and let them
+	 * run.
+	 */
+	close(startup_pipe[0]);
+	close(startup_pipe[1]);
+
 	for (;;) {
 		/* Did we get a signal asking us to exit? */
 		if (terminate)
@@ -510,7 +549,7 @@ int main(int argc, char **argv)
 		 * useful in emulation where we will both be slow and
 		 * likely to have a large set of VLs.
 		 */
-		ret = epoll_wait(epoll_fd, &ev, 1, 1000);
+		ret = epoll_wait(epoll_fd, evs, tests, 1000);
 		if (ret < 0) {
 			if (errno == EINTR)
 				continue;
@@ -519,13 +558,40 @@ int main(int argc, char **argv)
 		}
 
 		/* Output? */
-		if (ret == 1) {
-			child_output(ev.data.ptr, ev.events, false);
+		if (ret > 0) {
+			for (i = 0; i < ret; i++) {
+				child_output(evs[i].data.ptr, evs[i].events,
+					     false);
+			}
 			continue;
 		}
 
 		/* Otherwise epoll_wait() timed out */
 
+		/*
+		 * If the child processes have not produced output they
+		 * aren't actually running the tests yet .
+		 */
+		if (!all_children_started) {
+			seen_children = 0;
+
+			for (i = 0; i < num_children; i++)
+				if (children[i].output_seen ||
+				    children[i].exited)
+					seen_children++;
+
+			if (seen_children != num_children) {
+				ksft_print_msg("Waiting for %d children\n",
+					       num_children - seen_children);
+				continue;
+			}
+
+			all_children_started = true;
+		}
+
+		ksft_print_msg("Sending signals, timeout remaining: %d\n",
+			       timeout);
+
 		for (i = 0; i < num_children; i++)
 			child_tickle(&children[i]);
 
diff --git a/tools/testing/selftests/arm64/mte/check_buffer_fill.c b/tools/testing/selftests/arm64/mte/check_buffer_fill.c
index 75fc482d63b6..1dbbbd47dd50 100644
--- a/tools/testing/selftests/arm64/mte/check_buffer_fill.c
+++ b/tools/testing/selftests/arm64/mte/check_buffer_fill.c
@@ -32,7 +32,7 @@ static int check_buffer_by_byte(int mem_type, int mode)
 	bool err;
 
 	mte_switch_mode(mode, MTE_ALLOW_NON_ZERO_TAG);
-	item = sizeof(sizes)/sizeof(int);
+	item = ARRAY_SIZE(sizes);
 
 	for (i = 0; i < item; i++) {
 		ptr = (char *)mte_allocate_memory(sizes[i], mem_type, 0, true);
@@ -69,7 +69,7 @@ static int check_buffer_underflow_by_byte(int mem_type, int mode,
 	char *und_ptr = NULL;
 
 	mte_switch_mode(mode, MTE_ALLOW_NON_ZERO_TAG);
-	item = sizeof(sizes)/sizeof(int);
+	item = ARRAY_SIZE(sizes);
 	for (i = 0; i < item; i++) {
 		ptr = (char *)mte_allocate_memory_tag_range(sizes[i], mem_type, 0,
 							    underflow_range, 0);
@@ -165,7 +165,7 @@ static int check_buffer_overflow_by_byte(int mem_type, int mode,
 	char *over_ptr = NULL;
 
 	mte_switch_mode(mode, MTE_ALLOW_NON_ZERO_TAG);
-	item = sizeof(sizes)/sizeof(int);
+	item = ARRAY_SIZE(sizes);
 	for (i = 0; i < item; i++) {
 		ptr = (char *)mte_allocate_memory_tag_range(sizes[i], mem_type, 0,
 							    0, overflow_range);
@@ -338,7 +338,7 @@ static int check_buffer_by_block(int mem_type, int mode)
 	int i, item, result = KSFT_PASS;
 
 	mte_switch_mode(mode, MTE_ALLOW_NON_ZERO_TAG);
-	item = sizeof(sizes)/sizeof(int);
+	item = ARRAY_SIZE(sizes);
 	cur_mte_cxt.fault_valid = false;
 	for (i = 0; i < item; i++) {
 		result = check_buffer_by_block_iterate(mem_type, mode, sizes[i]);
@@ -366,7 +366,7 @@ static int check_memory_initial_tags(int mem_type, int mode, int mapping)
 {
 	char *ptr;
 	int run, fd;
-	int total = sizeof(sizes)/sizeof(int);
+	int total = ARRAY_SIZE(sizes);
 
 	mte_switch_mode(mode, MTE_ALLOW_NON_ZERO_TAG);
 	for (run = 0; run < total; run++) {
@@ -404,7 +404,7 @@ int main(int argc, char *argv[])
 {
 	int err;
 	size_t page_size = getpagesize();
-	int item = sizeof(sizes)/sizeof(int);
+	int item = ARRAY_SIZE(sizes);
 
 	sizes[item - 3] = page_size - 1;
 	sizes[item - 2] = page_size;
diff --git a/tools/testing/selftests/arm64/mte/check_mmap_options.c b/tools/testing/selftests/arm64/mte/check_mmap_options.c
index a04b12c21ac9..17694caaff53 100644
--- a/tools/testing/selftests/arm64/mte/check_mmap_options.c
+++ b/tools/testing/selftests/arm64/mte/check_mmap_options.c
@@ -61,9 +61,8 @@ static int check_anonymous_memory_mapping(int mem_type, int mode, int mapping, i
 {
 	char *ptr, *map_ptr;
 	int run, result, map_size;
-	int item = sizeof(sizes)/sizeof(int);
+	int item = ARRAY_SIZE(sizes);
 
-	item = sizeof(sizes)/sizeof(int);
 	mte_switch_mode(mode, MTE_ALLOW_NON_ZERO_TAG);
 	for (run = 0; run < item; run++) {
 		map_size = sizes[run] + OVERFLOW + UNDERFLOW;
@@ -93,7 +92,7 @@ static int check_file_memory_mapping(int mem_type, int mode, int mapping, int ta
 {
 	char *ptr, *map_ptr;
 	int run, fd, map_size;
-	int total = sizeof(sizes)/sizeof(int);
+	int total = ARRAY_SIZE(sizes);
 	int result = KSFT_PASS;
 
 	mte_switch_mode(mode, MTE_ALLOW_NON_ZERO_TAG);
@@ -132,7 +131,7 @@ static int check_clear_prot_mte_flag(int mem_type, int mode, int mapping)
 {
 	char *ptr, *map_ptr;
 	int run, prot_flag, result, fd, map_size;
-	int total = sizeof(sizes)/sizeof(int);
+	int total = ARRAY_SIZE(sizes);
 
 	prot_flag = PROT_READ | PROT_WRITE;
 	mte_switch_mode(mode, MTE_ALLOW_NON_ZERO_TAG);
@@ -187,7 +186,7 @@ static int check_clear_prot_mte_flag(int mem_type, int mode, int mapping)
 int main(int argc, char *argv[])
 {
 	int err;
-	int item = sizeof(sizes)/sizeof(int);
+	int item = ARRAY_SIZE(sizes);
 
 	err = mte_default_setup();
 	if (err)
diff --git a/tools/testing/selftests/arm64/signal/testcases/TODO b/tools/testing/selftests/arm64/signal/testcases/TODO
index 110ff9fd195d..1f7fba8194fe 100644
--- a/tools/testing/selftests/arm64/signal/testcases/TODO
+++ b/tools/testing/selftests/arm64/signal/testcases/TODO
@@ -1,2 +1 @@
 - Validate that register contents are saved and restored as expected.
-- Support and validate extra_context.
diff --git a/tools/testing/selftests/arm64/signal/testcases/testcases.c b/tools/testing/selftests/arm64/signal/testcases/testcases.c
index e1c625b20ac4..d2eda7b5de26 100644
--- a/tools/testing/selftests/arm64/signal/testcases/testcases.c
+++ b/tools/testing/selftests/arm64/signal/testcases/testcases.c
@@ -1,5 +1,9 @@
 // SPDX-License-Identifier: GPL-2.0
 /* Copyright (C) 2019 ARM Limited */
+
+#include <ctype.h>
+#include <string.h>
+
 #include "testcases.h"
 
 struct _aarch64_ctx *get_header(struct _aarch64_ctx *head, uint32_t magic,
@@ -109,7 +113,7 @@ bool validate_reserved(ucontext_t *uc, size_t resv_sz, char **err)
 	bool terminated = false;
 	size_t offs = 0;
 	int flags = 0;
-	int new_flags;
+	int new_flags, i;
 	struct extra_context *extra = NULL;
 	struct sve_context *sve = NULL;
 	struct za_context *za = NULL;
@@ -117,6 +121,7 @@ bool validate_reserved(ucontext_t *uc, size_t resv_sz, char **err)
 		(struct _aarch64_ctx *)uc->uc_mcontext.__reserved;
 	void *extra_data = NULL;
 	size_t extra_sz = 0;
+	char magic[4];
 
 	if (!err)
 		return false;
@@ -194,11 +199,19 @@ bool validate_reserved(ucontext_t *uc, size_t resv_sz, char **err)
 			/*
 			 * A still unknown Magic: potentially freshly added
 			 * to the Kernel code and still unknown to the
-			 * tests.
+			 * tests.  Magic numbers are supposed to be allocated
+			 * as somewhat meaningful ASCII strings so try to
+			 * print as such as well as the raw number.
 			 */
+			memcpy(magic, &head->magic, sizeof(magic));
+			for (i = 0; i < sizeof(magic); i++)
+				if (!isalnum(magic[i]))
+					magic[i] = '?';
+
 			fprintf(stdout,
-				"SKIP Unknown MAGIC: 0x%X - Is KSFT arm64/signal up to date ?\n",
-				head->magic);
+				"SKIP Unknown MAGIC: 0x%X (%c%c%c%c) - Is KSFT arm64/signal up to date ?\n",
+				head->magic,
+				magic[3], magic[2], magic[1], magic[0]);
 			break;
 		}