tools/perf: Fix compilation issues

All changes were backported from v4.20.1 kernel

tools/include/linux/compiler.h

 #ifndef _TOOLS_LINUX_COMPILER_H_
 #define _TOOLS_LINUX_COMPILER_H_
 
+#ifdef __GNUC__
+#include <linux/compiler-gcc.h>
+#endif
+
+#ifndef __compiletime_error
+# define __compiletime_error(message)
+#endif
+
 /* Optimization barrier */
 /* The "volatile" is due to gcc bugs */
 #define barrier() __asm__ __volatile__("": : :"memory")
@@ -9,6 +17,15 @@
 # define __always_inline	inline __attribute__((always_inline))
 #endif
 
+#ifndef noinline
+#define noinline
+#endif
+
+/* Are two types/vars the same type (ignoring qualifiers)? */
+#ifndef __same_type
+# define __same_type(a, b) __builtin_types_compatible_p(typeof(a), typeof(b))
+#endif
+
 #ifdef __ANDROID__
 /*
  * FIXME: Big hammer to get rid of tons of:

tools/perf/bench/numa.c

@@ -1572,13 +1572,13 @@ static int __bench_numa(const char *name)
 		"GB/sec,", "total-speed",	"GB/sec total speed");
 
 	if (g->p.show_details >= 2) {
-		char tname[32];
+		char tname[14 + 2 * 10 + 1];
 		struct thread_data *td;
 		for (p = 0; p < g->p.nr_proc; p++) {
 			for (t = 0; t < g->p.nr_threads; t++) {
-				memset(tname, 0, 32);
+				memset(tname, 0, sizeof(tname));
 				td = g->threads + p*g->p.nr_threads + t;
-				snprintf(tname, 32, "process%d:thread%d", p, t);
+				snprintf(tname, sizeof(tname), "process%d:thread%d", p, t);
 				print_res(tname, td->speed_gbs,
 					"GB/sec",	"thread-speed", "GB/sec/thread speed");
 				print_res(tname, td->system_time_ns / 1e9,

tools/perf/builtin-top.c

@@ -642,6 +642,7 @@ repeat:
 			if (errno == EINTR)
 				continue;
 			/* Fall trhu */
+			__fallthrough;
 		default:
 			c = getc(stdin);
 			tcsetattr(0, TCSAFLUSH, &save);

tools/perf/tests/parse-events.c

@@ -1779,15 +1779,14 @@ static int test_pmu_events(void)
 	}
 
 	while (!ret && (ent = readdir(dir))) {
-#define MAX_NAME 100
 		struct evlist_test e;
-		char name[MAX_NAME];
+		char name[2 * NAME_MAX + 1 + 12 + 3];
 
 		/* Names containing . are special and cannot be used directly */
 		if (strchr(ent->d_name, '.'))
 			continue;
 
-		snprintf(name, MAX_NAME, "cpu/event=%s/u", ent->d_name);
+		snprintf(name, sizeof(name), "cpu/event=%s/u", ent->d_name);
 
 		e.name  = name;
 		e.check = test__checkevent_pmu_events;
@@ -1795,11 +1794,10 @@ static int test_pmu_events(void)
 		ret = test_event(&e);
 		if (ret)
 			break;
-		snprintf(name, MAX_NAME, "%s:u,cpu/event=%s/u", ent->d_name, ent->d_name);
+		snprintf(name, sizeof(name), "%s:u,cpu/event=%s/u", ent->d_name, ent->d_name);
 		e.name  = name;
 		e.check = test__checkevent_pmu_events_mix;
 		ret = test_event(&e);
-#undef MAX_NAME
 	}
 
 	closedir(dir);

tools/perf/util/header.c

@@ -3185,6 +3185,7 @@ int perf_event__process_event_update(struct perf_tool *tool __maybe_unused,
 	case PERF_EVENT_UPDATE__SCALE:
 		ev_scale = (struct event_update_event_scale *) ev->data;
 		evsel->scale = ev_scale->scale;
+		__fallthrough;
 	case PERF_EVENT_UPDATE__CPUS:
 		ev_cpus = (struct event_update_event_cpus *) ev->data;
 

tools/perf/util/intel-pt-decoder/intel-pt-decoder.c

@@ -22,6 +22,7 @@
 #include <errno.h>
 #include <stdint.h>
 #include <inttypes.h>
+#include <linux/compiler.h>
 
 #include "../cache.h"
 #include "../util.h"
@@ -1676,6 +1677,7 @@ static int intel_pt_walk_psb(struct intel_pt_decoder *decoder)
 		switch (decoder->packet.type) {
 		case INTEL_PT_TIP_PGD:
 			decoder->continuous_period = false;
+			__fallthrough;
 		case INTEL_PT_TIP_PGE:
 		case INTEL_PT_TIP:
 			intel_pt_log("ERROR: Unexpected packet\n");
@@ -1729,6 +1731,7 @@ static int intel_pt_walk_psb(struct intel_pt_decoder *decoder)
 			decoder->pge = false;
 			decoder->continuous_period = false;
 			intel_pt_clear_tx_flags(decoder);
+			__fallthrough;
 		case INTEL_PT_TNT:
 			decoder->have_tma = false;
 			intel_pt_log("ERROR: Unexpected packet\n");
@@ -1769,6 +1772,7 @@ static int intel_pt_walk_to_ip(struct intel_pt_decoder *decoder)
 		switch (decoder->packet.type) {
 		case INTEL_PT_TIP_PGD:
 			decoder->continuous_period = false;
+			__fallthrough;
 		case INTEL_PT_TIP_PGE:
 		case INTEL_PT_TIP:
 			decoder->pge = decoder->packet.type != INTEL_PT_TIP_PGD;

tools/perf/util/intel-pt-decoder/intel-pt-pkt-decoder.c

@@ -17,6 +17,7 @@
 #include <string.h>
 #include <endian.h>
 #include <byteswap.h>
+#include <linux/compiler.h>
 
 #include "intel-pt-pkt-decoder.h"
 
@@ -498,6 +499,7 @@ int intel_pt_pkt_desc(const struct intel_pt_pkt *packet, char *buf,
 	case INTEL_PT_FUP:
 		if (!(packet->count))
 			return snprintf(buf, buf_len, "%s no ip", name);
+		__fallthrough;
 	case INTEL_PT_CYC:
 	case INTEL_PT_VMCS:
 	case INTEL_PT_MTC:

tools/perf/util/strfilter.c

@@ -269,6 +269,8 @@ static int strfilter_node__sprint(struct strfilter_node *node, char *buf)
 		len = strfilter_node__sprint_pt(node->l, buf);
 		if (len < 0)
 			return len;
+
+		__fallthrough;
 	case '!':
 		if (buf) {
 			*(buf + len++) = *node->p;

tools/perf/util/string.c

@@ -21,6 +21,8 @@ s64 perf_atoll(const char *str)
 		case 'b': case 'B':
 			if (*p)
 				goto out_err;
+
+			__fallthrough;
 		case '\0':
 			return length;
 		default:

tools/perf/util/thread_map.c

@@ -93,7 +93,7 @@ struct thread_map *thread_map__new_by_uid(uid_t uid)
 {
 	DIR *proc;
 	int max_threads = 32, items, i;
-	char path[256];
+	char path[NAME_MAX + 1 + 6];
 	struct dirent *dirent, **namelist = NULL;
 	struct thread_map *threads = thread_map__alloc(max_threads);