--- zzzz-none-000/linux-3.10.107/tools/net/bpf_jit_disasm.c	2017-06-27 09:49:32.000000000 +0000
+++ scorpion-7490-727/linux-3.10.107/tools/net/bpf_jit_disasm.c	2021-02-04 17:41:59.000000000 +0000
@@ -22,9 +22,14 @@
 #include <string.h>
 #include <bfd.h>
 #include <dis-asm.h>
+#include <regex.h>
+#include <fcntl.h>
 #include <sys/klog.h>
 #include <sys/types.h>
-#include <regex.h>
+#include <sys/stat.h>
+
+#define CMD_ACTION_SIZE_BUFFER		10
+#define CMD_ACTION_READ_ALL		3
 
 static void get_exec_path(char *tpath, size_t size)
 {
@@ -43,8 +48,7 @@
 	free(path);
 }
 
-static void get_asm_insns(uint8_t *image, size_t len, unsigned long base,
-			  int opcodes)
+static void get_asm_insns(uint8_t *image, size_t len, int opcodes)
 {
 	int count, i, pc = 0;
 	char tpath[256];
@@ -88,32 +92,78 @@
 	bfd_close(bfdf);
 }
 
-static char *get_klog_buff(int *klen)
+static char *get_klog_buff(unsigned int *klen)
 {
-	int ret, len = klogctl(10, NULL, 0);
-	char *buff = malloc(len);
+	int ret, len;
+	char *buff;
+
+	len = klogctl(CMD_ACTION_SIZE_BUFFER, NULL, 0);
+	buff = malloc(len);
+	if (!buff)
+		return NULL;
+
+	ret = klogctl(CMD_ACTION_READ_ALL, buff, len);
+	if (ret < 0) {
+		free(buff);
+		return NULL;
+	}
 
-	assert(buff && klen);
-	ret = klogctl(3, buff, len);
-	assert(ret >= 0);
 	*klen = ret;
+	return buff;
+}
 
+static char *get_flog_buff(const char *file, unsigned int *klen)
+{
+	int fd, ret, len;
+	struct stat fi;
+	char *buff;
+
+	fd = open(file, O_RDONLY);
+	if (fd < 0)
+		return NULL;
+
+	ret = fstat(fd, &fi);
+	if (ret < 0 || !S_ISREG(fi.st_mode))
+		goto out;
+
+	len = fi.st_size + 1;
+	buff = malloc(len);
+	if (!buff)
+		goto out;
+
+	memset(buff, 0, len);
+	ret = read(fd, buff, len - 1);
+	if (ret <= 0)
+		goto out_free;
+
+	close(fd);
+	*klen = ret;
 	return buff;
+out_free:
+	free(buff);
+out:
+	close(fd);
+	return NULL;
+}
+
+static char *get_log_buff(const char *file, unsigned int *klen)
+{
+	return file ? get_flog_buff(file, klen) : get_klog_buff(klen);
 }
 
-static void put_klog_buff(char *buff)
+static void put_log_buff(char *buff)
 {
 	free(buff);
 }
 
-static int get_last_jit_image(char *haystack, size_t hlen,
-			      uint8_t *image, size_t ilen,
-			      unsigned long *base)
+static unsigned int get_last_jit_image(char *haystack, size_t hlen,
+				       uint8_t *image, size_t ilen)
 {
 	char *ptr, *pptr, *tmp;
 	off_t off = 0;
 	int ret, flen, proglen, pass, ulen = 0;
 	regmatch_t pmatch[1];
+	unsigned long base;
 	regex_t regex;
 
 	if (hlen == 0)
@@ -124,6 +174,8 @@
 	assert(ret == 0);
 
 	ptr = haystack;
+	memset(pmatch, 0, sizeof(pmatch));
+
 	while (1) {
 		ret = regexec(&regex, ptr, 1, pmatch, 0);
 		if (ret == 0) {
@@ -136,9 +188,11 @@
 
 	ptr = haystack + off - (pmatch[0].rm_eo - pmatch[0].rm_so);
 	ret = sscanf(ptr, "flen=%d proglen=%d pass=%d image=%lx",
-		     &flen, &proglen, &pass, base);
-	if (ret != 4)
+		     &flen, &proglen, &pass, &base);
+	if (ret != 4) {
+		regfree(&regex);
 		return 0;
+	}
 
 	tmp = ptr = haystack + off;
 	while ((ptr = strtok(tmp, "\n")) != NULL && ulen < ilen) {
@@ -162,38 +216,55 @@
 	assert(ulen == proglen);
 	printf("%d bytes emitted from JIT compiler (pass:%d, flen:%d)\n",
 	       proglen, pass, flen);
-	printf("%lx + <x>:\n", *base);
+	printf("%lx + <x>:\n", base);
 
 	regfree(&regex);
 	return ulen;
 }
 
-int main(int argc, char **argv)
+static void usage(void)
 {
-	int len, klen, opcodes = 0;
-	char *kbuff;
-	unsigned long base;
-	uint8_t image[4096];
+	printf("Usage: bpf_jit_disasm [...]\n");
+	printf("       -o          Also display related opcodes (default: off).\n");
+	printf("       -f <file>   Read last image dump from file or stdin (default: klog).\n");
+	printf("       -h          Display this help.\n");
+}
 
-	if (argc > 1) {
-		if (!strncmp("-o", argv[argc - 1], 2)) {
+int main(int argc, char **argv)
+{
+	unsigned int len, klen, opt, opcodes = 0;
+	static uint8_t image[32768];
+	char *kbuff, *file = NULL;
+
+	while ((opt = getopt(argc, argv, "of:")) != -1) {
+		switch (opt) {
+		case 'o':
 			opcodes = 1;
-		} else {
-			printf("usage: bpf_jit_disasm [-o: show opcodes]\n");
-			exit(0);
+			break;
+		case 'f':
+			file = optarg;
+			break;
+		default:
+			usage();
+			return -1;
 		}
 	}
 
 	bfd_init();
 	memset(image, 0, sizeof(image));
 
-	kbuff = get_klog_buff(&klen);
-
-	len = get_last_jit_image(kbuff, klen, image, sizeof(image), &base);
-	if (len > 0 && base > 0)
-		get_asm_insns(image, len, base, opcodes);
+	kbuff = get_log_buff(file, &klen);
+	if (!kbuff) {
+		fprintf(stderr, "Could not retrieve log buffer!\n");
+		return -1;
+	}
 
-	put_klog_buff(kbuff);
+	len = get_last_jit_image(kbuff, klen, image, sizeof(image));
+	if (len > 0)
+		get_asm_insns(image, len, opcodes);
+	else
+		fprintf(stderr, "No JIT image found!\n");
 
+	put_log_buff(kbuff);
 	return 0;
 }