ftrace: Synchronize the initialization of ftrace_opsgrafted

There's some internal state that ftrace_ops needs to have set, but since
it can be declared outside of the ftrace.c code, it calls
ftrace_ops_init() on the ops in every global function. The issue is that
if two tasks call it on the same ops at the same time it is possible to
have the initialization of one corrupt the initialization of the other
call.

Create a ops_mutex to use to synchronize every initialization of the
ftrace_ops. The mutex is taken within checking the ftrace_ops flag that
states it was initializied but the flag is checked again after the mutex
has been taken. Checking first outside the mutex allows it to shortcut
having to take the mutex. But then the check needs to be done again after
the mute is taken in case of races.

Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260902095501.6b59af20@gandalf.local.home
Fixes: f04f24fb7e48d ("ftrace, kprobes: Fix a deadlock on ftrace_regex_lock")
Reported-by: sashiko-bot@kernel.org
Close: https://lore.kernel.org/all/20260829025528.49A831F000E9@smtp.kernel.org/
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

1 files changed, 289 insertions, 0 deletions

diff --git a/tools/firmware/ihex2fw.c b/tools/firmware/ihex2fw.c
new file mode 100644
index 000000000..2ebed4768
--- /dev/null
+++ b/tools/firmware/ihex2fw.c
@@ -0,0 +1,289 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Parser/loader for IHEX formatted data.
+ *
+ * Copyright © 2008 David Woodhouse <dwmw2@infradead.org>
+ * Copyright © 2005 Jan Harkes <jaharkes@cs.cmu.edu>
+ */
+
+#include <stdint.h>
+#include <arpa/inet.h>
+#include <stdio.h>
+#include <errno.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/mman.h>
+#include <fcntl.h>
+#include <string.h>
+#include <unistd.h>
+#include <stdlib.h>
+#define _GNU_SOURCE
+#include <getopt.h>
+
+
+#define __ALIGN_KERNEL_MASK(x, mask)	(((x) + (mask)) & ~(mask))
+#define __ALIGN_KERNEL(x, a)		__ALIGN_KERNEL_MASK(x, (typeof(x))(a) - 1)
+#define ALIGN(x, a)			__ALIGN_KERNEL((x), (a))
+
+struct ihex_binrec {
+	struct ihex_binrec *next; /* not part of the real data structure */
+        uint32_t addr;
+        uint16_t len;
+        uint8_t data[];
+};
+
+/**
+ * nybble/hex are little helpers to parse hexadecimal numbers to a byte value
+ **/
+static uint8_t nybble(const uint8_t n)
+{
+	if      (n >= '0' && n <= '9') return n - '0';
+	else if (n >= 'A' && n <= 'F') return n - ('A' - 10);
+	else if (n >= 'a' && n <= 'f') return n - ('a' - 10);
+	return 0;
+}
+
+static uint8_t hex(const uint8_t *data, uint8_t *crc)
+{
+	uint8_t val = (nybble(data[0]) << 4) | nybble(data[1]);
+	*crc += val;
+	return val;
+}
+
+static int process_ihex(uint8_t *data, ssize_t size);
+static void file_record(struct ihex_binrec *record);
+static int output_records(int outfd);
+
+static int sort_records = 0;
+static int wide_records = 0;
+static int include_jump = 0;
+
+static int usage(void)
+{
+	fprintf(stderr, "ihex2fw: Convert ihex files into binary "
+		"representation for use by Linux kernel\n");
+	fprintf(stderr, "usage: ihex2fw [<options>] <src.HEX> <dst.fw>\n");
+	fprintf(stderr, "       -w: wide records (16-bit length)\n");
+	fprintf(stderr, "       -s: sort records by address\n");
+	fprintf(stderr, "       -j: include records for CS:IP/EIP address\n");
+	return 1;
+}
+
+int main(int argc, char **argv)
+{
+	int infd, outfd;
+	struct stat st;
+	uint8_t *data;
+	int opt;
+
+	while ((opt = getopt(argc, argv, "wsj")) != -1) {
+		switch (opt) {
+		case 'w':
+			wide_records = 1;
+			break;
+		case 's':
+			sort_records = 1;
+			break;
+		case 'j':
+			include_jump = 1;
+			break;
+		default:
+			return usage();
+		}
+	}
+
+	if (optind + 2 != argc)
+		return usage();
+
+	if (!strcmp(argv[optind], "-"))
+		infd = 0;
+	else
+		infd = open(argv[optind], O_RDONLY);
+	if (infd == -1) {
+		fprintf(stderr, "Failed to open source file: %s",
+			strerror(errno));
+		return usage();
+	}
+	if (fstat(infd, &st)) {
+		perror("stat");
+		return 1;
+	}
+	data = mmap(NULL, st.st_size, PROT_READ, MAP_SHARED, infd, 0);
+	if (data == MAP_FAILED) {
+		perror("mmap");
+		return 1;
+	}
+
+	if (!strcmp(argv[optind+1], "-"))
+		outfd = 1;
+	else
+		outfd = open(argv[optind+1], O_TRUNC|O_CREAT|O_WRONLY, 0644);
+	if (outfd == -1) {
+		fprintf(stderr, "Failed to open destination file: %s",
+			strerror(errno));
+		return usage();
+	}
+	if (process_ihex(data, st.st_size))
+		return 1;
+
+	return output_records(outfd);
+}
+
+static int process_ihex(uint8_t *data, ssize_t size)
+{
+	struct ihex_binrec *record;
+	size_t record_size;
+	uint32_t offset = 0;
+	uint32_t data32;
+	uint8_t type, crc = 0, crcbyte = 0;
+	int i, j;
+	int line = 1;
+	int len;
+
+	i = 0;
+next_record:
+	/* search for the start of record character */
+	while (i < size) {
+		if (data[i] == '\n') line++;
+		if (data[i++] == ':') break;
+	}
+
+	/* Minimum record length would be about 10 characters */
+	if (i + 10 > size) {
+		fprintf(stderr, "Can't find valid record at line %d\n", line);
+		return -EINVAL;
+	}
+
+	len = hex(data + i, &crc); i += 2;
+	if (wide_records) {
+		len <<= 8;
+		len += hex(data + i, &crc); i += 2;
+	}
+	record_size = ALIGN(sizeof(*record) + len, 4);
+	record = malloc(record_size);
+	if (!record) {
+		fprintf(stderr, "out of memory for records\n");
+		return -ENOMEM;
+	}
+	memset(record, 0, record_size);
+	record->len = len;
+
+	/* now check if we have enough data to read everything */
+	if (i + 8 + (record->len * 2) > size) {
+		fprintf(stderr, "Not enough data to read complete record at line %d\n",
+			line);
+		return -EINVAL;
+	}
+
+	record->addr  = hex(data + i, &crc) << 8; i += 2;
+	record->addr |= hex(data + i, &crc); i += 2;
+	type = hex(data + i, &crc); i += 2;
+
+	for (j = 0; j < record->len; j++, i += 2)
+		record->data[j] = hex(data + i, &crc);
+
+	/* check CRC */
+	crcbyte = hex(data + i, &crc); i += 2;
+	if (crc != 0) {
+		fprintf(stderr, "CRC failure at line %d: got 0x%X, expected 0x%X\n",
+			line, crcbyte, (unsigned char)(crcbyte-crc));
+		return -EINVAL;
+	}
+
+	/* Done reading the record */
+	switch (type) {
+	case 0:
+		/* old style EOF record? */
+		if (!record->len)
+			break;
+
+		record->addr += offset;
+		file_record(record);
+		goto next_record;
+
+	case 1: /* End-Of-File Record */
+		if (record->addr || record->len) {
+			fprintf(stderr, "Bad EOF record (type 01) format at line %d",
+				line);
+			return -EINVAL;
+		}
+		break;
+
+	case 2: /* Extended Segment Address Record (HEX86) */
+	case 4: /* Extended Linear Address Record (HEX386) */
+		if (record->addr || record->len != 2) {
+			fprintf(stderr, "Bad HEX86/HEX386 record (type %02X) at line %d\n",
+				type, line);
+			return -EINVAL;
+		}
+
+		/* We shouldn't really be using the offset for HEX86 because
+		 * the wraparound case is specified quite differently. */
+		offset = record->data[0] << 8 | record->data[1];
+		offset <<= (type == 2 ? 4 : 16);
+		goto next_record;
+
+	case 3: /* Start Segment Address Record */
+	case 5: /* Start Linear Address Record */
+		if (record->addr || record->len != 4) {
+			fprintf(stderr, "Bad Start Address record (type %02X) at line %d\n",
+				type, line);
+			return -EINVAL;
+		}
+
+		memcpy(&data32, &record->data[0], sizeof(data32));
+		data32 = htonl(data32);
+		memcpy(&record->data[0], &data32, sizeof(data32));
+
+		/* These records contain the CS/IP or EIP where execution
+		 * starts. If requested output this as a record. */
+		if (include_jump)
+			file_record(record);
+		goto next_record;
+
+	default:
+		fprintf(stderr, "Unknown record (type %02X)\n", type);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static struct ihex_binrec *records;
+
+static void file_record(struct ihex_binrec *record)
+{
+	struct ihex_binrec **p = &records;
+
+	while ((*p) && (!sort_records || (*p)->addr < record->addr))
+		p = &((*p)->next);
+
+	record->next = *p;
+	*p = record;
+}
+
+static uint16_t ihex_binrec_size(struct ihex_binrec *p)
+{
+	return p->len + sizeof(p->addr) + sizeof(p->len);
+}
+
+static int output_records(int outfd)
+{
+	unsigned char zeroes[6] = {0, 0, 0, 0, 0, 0};
+	struct ihex_binrec *p = records;
+
+	while (p) {
+		uint16_t writelen = ALIGN(ihex_binrec_size(p), 4);
+
+		p->addr = htonl(p->addr);
+		p->len = htons(p->len);
+		if (write(outfd, &p->addr, writelen) != writelen)
+			return 1;
+		p = p->next;
+	}
+	/* EOF record is zero length, since we don't bother to represent
+	   the type field in the binary version */
+	if (write(outfd, zeroes, 6) != 6)
+		return 1;
+	return 0;
+}