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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-19 02:56:35 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-19 02:56:35 +0000 |
commit | eba0cfa6b0bef4f2e73c8630a7efa3944df8b0f8 (patch) | |
tree | 74c37eede1f0634cc5de1c63c934edaa1630c6bc /kexec/firmware_memmap.c | |
parent | Initial commit. (diff) | |
download | kexec-tools-upstream/1%2.0.27.tar.xz kexec-tools-upstream/1%2.0.27.zip |
Adding upstream version 1:2.0.27.upstream/1%2.0.27upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'kexec/firmware_memmap.c')
-rw-r--r-- | kexec/firmware_memmap.c | 302 |
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; +} + |