1 files changed, 302 insertions, 0 deletions
diff --git a/kexec/firmware_memmap.c b/kexec/firmware_memmap.c
new file mode 100644
index 0000000..457c3dc
--- /dev/null
+++ b/kexec/firmware_memmap.c
@@ -0,0 +1,302 @@
+/*
+ * firmware_memmap.c: Read /sys/firmware/memmap
+ *
+ * Created by: Bernhard Walle (bernhard.walle@gmx.de)
+ * Copyright (C) SUSE LINUX Products GmbH, 2008. All rights reserved
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation (version 2 of the License).
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+#define _GNU_SOURCE /* for ULLONG_MAX without C99 */
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <dirent.h>
+#include <unistd.h>
+#include <limits.h>
+#include <errno.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+
+#include "firmware_memmap.h"
+#include "kexec.h"
+
+/*
+ * If the system is too old for ULLONG_MAX or LLONG_MAX, define it here.
+ */
+#ifndef ULLONG_MAX
+#    define ULLONG_MAX (~0ULL)
+#endif /* ULLONG_MAX */
+
+#ifndef LLONG_MAX
+#    define LLONG_MAX (~0ULL >> 1)
+#endif /* LLONG_MAX */
+
+
+/**
+ * The full path to the sysfs interface that provides the memory map.
+ */
+#define FIRMWARE_MEMMAP_DIR  "/sys/firmware/memmap"
+
+/**
+ * Parses a file that only contains one number. Typical for sysfs files.
+ *
+ * @param[in] filename the name of the file that should be parsed
+ * @return the value that has been read or ULLONG_MAX on error.
+ */
+static unsigned long long parse_numeric_sysfs(const char *filename)
+{
+	FILE *fp;
+	char linebuffer[BUFSIZ];
+	unsigned long long retval = ULLONG_MAX;
+
+	fp = fopen(filename, "r");
+	if (!fp) {
+		fprintf(stderr, "Opening \"%s\" failed: %s\n",
+			filename, strerror(errno));
+		return ULLONG_MAX;
+	}
+
+	if (!fgets(linebuffer, BUFSIZ, fp))
+		goto err;
+
+	linebuffer[BUFSIZ-1] = 0;
+
+	/* let strtoll() detect the base */
+	retval = strtoll(linebuffer, NULL, 0);
+
+err:
+	fclose(fp);
+
+	return retval;
+}
+
+/**
+ * Reads the contents of a one-line sysfs file to buffer. (This function is
+ * not threadsafe.)
+ *
+ * @param[in] filename the name of the file that should be read
+ *
+ * @return NULL on failure, a pointer to a static buffer (that should be copied
+ *         with strdup() if the caller plans to use it after next function call)
+ */
+static char *parse_string_sysfs(const char *filename)
+{
+	FILE *fp;
+	static char linebuffer[BUFSIZ];
+	char *end;
+
+	fp = fopen(filename, "r");
+	if (!fp) {
+		fprintf(stderr, "Opening \"%s\" failed: %s\n",
+			filename, strerror(errno));
+		return NULL;
+	}
+
+	if (!fgets(linebuffer, BUFSIZ, fp)) {
+		fclose(fp);
+		return NULL;
+	}
+
+	linebuffer[BUFSIZ-1] = 0;
+
+	/* truncate trailing newline(s) */
+	end = linebuffer + strlen(linebuffer) - 1;
+	while (*end == '\n')
+		*end-- = 0;
+
+	fclose(fp);
+
+	return linebuffer;
+
+}
+
+static int parse_memmap_entry(const char *entry, struct memory_range *range)
+{
+	char filename[PATH_MAX];
+	char *type;
+	int ret;
+
+	/*
+	 * entry/start
+	 */
+	ret = snprintf(filename, PATH_MAX, "%s/%s", entry, "start");
+	if (ret < 0 || ret >= PATH_MAX) {
+		fprintf(stderr, "snprintf failed: %s\n", strerror(errno));
+		return -1;
+	}
+
+	filename[PATH_MAX-1] = 0;
+
+	range->start = parse_numeric_sysfs(filename);
+	if (range->start == ULLONG_MAX)
+		return -1;
+
+	/*
+	 * entry/end
+	 */
+	ret = snprintf(filename, PATH_MAX, "%s/%s", entry, "end");
+	if (ret < 0 || ret >= PATH_MAX) {
+		fprintf(stderr, "snprintf failed: %s\n", strerror(errno));
+		return -1;
+	}
+
+	filename[PATH_MAX-1] = 0;
+
+	range->end = parse_numeric_sysfs(filename);
+	if (range->end == ULLONG_MAX)
+		return -1;
+
+	/*
+	 * entry/type
+	 */
+	ret = snprintf(filename, PATH_MAX, "%s/%s", entry, "type");
+	if (ret < 0 || ret >= PATH_MAX) {
+		fprintf(stderr, "snprintf failed: %s\n", strerror(errno));
+		return -1;
+	}
+
+	filename[PATH_MAX-1] = 0;
+
+	type = parse_string_sysfs(filename);
+	if (!type)
+		return -1;
+
+	if (strcmp(type, "System RAM") == 0)
+		range->type = RANGE_RAM;
+	else if (strcmp(type, "ACPI Tables") == 0)
+		range->type = RANGE_ACPI;
+	else if (strcmp(type, "Unusable memory") == 0)
+		range->type = RANGE_RESERVED;
+	else if (strcmp(type, "reserved") == 0)
+		range->type = RANGE_RESERVED;
+	else if (strcmp(type, "Reserved") == 0)
+		range->type = RANGE_RESERVED;
+	else if (strcmp(type, "Unknown E820 type") == 0)
+		range->type = RANGE_RESERVED;
+	else if (strcmp(type, "ACPI Non-volatile Storage") == 0)
+		range->type = RANGE_ACPI_NVS;
+	else if (strcmp(type, "Uncached RAM") == 0)
+		range->type = RANGE_UNCACHED;
+	else if (strcmp(type, "Persistent Memory (legacy)") == 0)
+		range->type = RANGE_PRAM;
+	else if (strcmp(type, "Persistent Memory") == 0)
+		range->type = RANGE_PMEM;
+	else {
+		fprintf(stderr, "Unknown type (%s) while parsing %s. Please "
+			"report this as bug. Using RANGE_RESERVED now.\n",
+			type, filename);
+		range->type = RANGE_RESERVED;
+	}
+
+	return 0;
+}
+
+/* documentation: firmware_memmap.h */
+int compare_ranges(const void *first, const void *second)
+{
+	const struct memory_range *first_range = first;
+	const struct memory_range *second_range = second;
+
+	/*
+	 * don't use the "first_range->start - second_range->start"
+	 * notation because unsigned long long might overflow
+	 */
+	if (first_range->start > second_range->start)
+		return 1;
+	else if (first_range->start < second_range->start)
+		return -1;
+	else /* first_range->start == second_range->start */
+		return 0;
+}
+
+/* documentation: firmware_memmap.h */
+int have_sys_firmware_memmap(void)
+{
+	int ret;
+	struct stat mystat;
+
+	ret = stat(FIRMWARE_MEMMAP_DIR, &mystat);
+	if (ret != 0)
+		return 0;
+
+	return S_ISDIR(mystat.st_mode);
+}
+
+/* documentation: firmware_memmap.h */
+int get_firmware_memmap_ranges(struct memory_range *range, size_t *ranges)
+{
+	DIR *firmware_memmap_dir = NULL;
+	struct dirent *dirent;
+	int i = 0;
+
+	/* argument checking */
+	if (!range || !ranges) {
+		fprintf(stderr, "%s: Invalid arguments.\n", __FUNCTION__);
+		return -1;
+	}
+
+	/* open the directory */
+	firmware_memmap_dir = opendir(FIRMWARE_MEMMAP_DIR);
+	if (!firmware_memmap_dir) {
+		perror("Could not open \"" FIRMWARE_MEMMAP_DIR "\"");
+		goto error;
+	}
+
+	/* parse the entries */
+	while ((dirent = readdir(firmware_memmap_dir)) != NULL) {
+		int ret;
+		char full_path[PATH_MAX];
+
+		/* array overflow check */
+		if ((size_t)i >= *ranges) {
+			fprintf(stderr, "The firmware provides more entries "
+				"allowed (%zd). Please report that as bug.\n",
+				*ranges);
+			goto error;
+		}
+
+		/* exclude '.' and '..' */
+		if (dirent->d_name[0] && dirent->d_name[0] == '.') {
+			continue;
+		}
+
+		snprintf(full_path, PATH_MAX, "%s/%s", FIRMWARE_MEMMAP_DIR,
+			dirent->d_name);
+		full_path[PATH_MAX-1] = 0;
+		ret = parse_memmap_entry(full_path, &range[i]);
+		if (ret < 0) {
+			goto error;
+		}
+
+		i++;
+	}
+
+	/* close the dir as we don't need it any more */
+	closedir(firmware_memmap_dir);
+
+	/* update the number of ranges for the caller */
+	*ranges = i;
+
+	/* and finally sort the entries with qsort */
+	qsort(range, *ranges, sizeof(struct memory_range), compare_ranges);
+
+	return 0;
+
+error:
+	if (firmware_memmap_dir) {
+		closedir(firmware_memmap_dir);
+	}
+	return -1;
+}
+