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author | Linus Torvalds <torvalds@linux-foundation.org> | 2020-02-06 07:12:11 +0000 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-02-06 07:12:11 +0000 |
commit | e310396bb8d7db977a0e10ef7b5040e98b89c34c (patch) | |
tree | 461357ada35c637292884f0af1dc9fc41c0203ff /tools/bootconfig/main.c | |
parent | Merge tag 'io_uring-5.6-2020-02-05' of git://git.kernel.dk/linux-block (diff) | |
parent | bootconfig: Show the number of nodes on boot message (diff) | |
download | linux-dev-e310396bb8d7db977a0e10ef7b5040e98b89c34c.tar.xz linux-dev-e310396bb8d7db977a0e10ef7b5040e98b89c34c.zip |
Merge tag 'trace-v5.6-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing updates from Steven Rostedt:
- Added new "bootconfig".
This looks for a file appended to initrd to add boot config options,
and has been discussed thoroughly at Linux Plumbers.
Very useful for adding kprobes at bootup.
Only enabled if "bootconfig" is on the real kernel command line.
- Created dynamic event creation.
Merges common code between creating synthetic events and kprobe
events.
- Rename perf "ring_buffer" structure to "perf_buffer"
- Rename ftrace "ring_buffer" structure to "trace_buffer"
Had to rename existing "trace_buffer" to "array_buffer"
- Allow trace_printk() to work withing (some) tracing code.
- Sort of tracing configs to be a little better organized
- Fixed bug where ftrace_graph hash was not being protected properly
- Various other small fixes and clean ups
* tag 'trace-v5.6-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (88 commits)
bootconfig: Show the number of nodes on boot message
tools/bootconfig: Show the number of bootconfig nodes
bootconfig: Add more parse error messages
bootconfig: Use bootconfig instead of boot config
ftrace: Protect ftrace_graph_hash with ftrace_sync
ftrace: Add comment to why rcu_dereference_sched() is open coded
tracing: Annotate ftrace_graph_notrace_hash pointer with __rcu
tracing: Annotate ftrace_graph_hash pointer with __rcu
bootconfig: Only load bootconfig if "bootconfig" is on the kernel cmdline
tracing: Use seq_buf for building dynevent_cmd string
tracing: Remove useless code in dynevent_arg_pair_add()
tracing: Remove check_arg() callbacks from dynevent args
tracing: Consolidate some synth_event_trace code
tracing: Fix now invalid var_ref_vals assumption in trace action
tracing: Change trace_boot to use synth_event interface
tracing: Move tracing selftests to bottom of menu
tracing: Move mmio tracer config up with the other tracers
tracing: Move tracing test module configs together
tracing: Move all function tracing configs together
tracing: Documentation for in-kernel synthetic event API
...
Diffstat (limited to 'tools/bootconfig/main.c')
-rw-r--r-- | tools/bootconfig/main.c | 354 |
1 files changed, 354 insertions, 0 deletions
diff --git a/tools/bootconfig/main.c b/tools/bootconfig/main.c new file mode 100644 index 000000000000..47f488458328 --- /dev/null +++ b/tools/bootconfig/main.c @@ -0,0 +1,354 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Boot config tool for initrd image + */ +#include <stdio.h> +#include <stdlib.h> +#include <sys/types.h> +#include <sys/stat.h> +#include <fcntl.h> +#include <unistd.h> +#include <string.h> +#include <errno.h> + +#include <linux/kernel.h> +#include <linux/bootconfig.h> + +int pr_output = 1; + +static int xbc_show_array(struct xbc_node *node) +{ + const char *val; + int i = 0; + + xbc_array_for_each_value(node, val) { + printf("\"%s\"%s", val, node->next ? ", " : ";\n"); + i++; + } + return i; +} + +static void xbc_show_compact_tree(void) +{ + struct xbc_node *node, *cnode; + int depth = 0, i; + + node = xbc_root_node(); + while (node && xbc_node_is_key(node)) { + for (i = 0; i < depth; i++) + printf("\t"); + cnode = xbc_node_get_child(node); + while (cnode && xbc_node_is_key(cnode) && !cnode->next) { + printf("%s.", xbc_node_get_data(node)); + node = cnode; + cnode = xbc_node_get_child(node); + } + if (cnode && xbc_node_is_key(cnode)) { + printf("%s {\n", xbc_node_get_data(node)); + depth++; + node = cnode; + continue; + } else if (cnode && xbc_node_is_value(cnode)) { + printf("%s = ", xbc_node_get_data(node)); + if (cnode->next) + xbc_show_array(cnode); + else + printf("\"%s\";\n", xbc_node_get_data(cnode)); + } else { + printf("%s;\n", xbc_node_get_data(node)); + } + + if (node->next) { + node = xbc_node_get_next(node); + continue; + } + while (!node->next) { + node = xbc_node_get_parent(node); + if (!node) + return; + if (!xbc_node_get_child(node)->next) + continue; + depth--; + for (i = 0; i < depth; i++) + printf("\t"); + printf("}\n"); + } + node = xbc_node_get_next(node); + } +} + +/* Simple real checksum */ +int checksum(unsigned char *buf, int len) +{ + int i, sum = 0; + + for (i = 0; i < len; i++) + sum += buf[i]; + + return sum; +} + +#define PAGE_SIZE 4096 + +int load_xbc_fd(int fd, char **buf, int size) +{ + int ret; + + *buf = malloc(size + 1); + if (!*buf) + return -ENOMEM; + + ret = read(fd, *buf, size); + if (ret < 0) + return -errno; + (*buf)[size] = '\0'; + + return ret; +} + +/* Return the read size or -errno */ +int load_xbc_file(const char *path, char **buf) +{ + struct stat stat; + int fd, ret; + + fd = open(path, O_RDONLY); + if (fd < 0) + return -errno; + ret = fstat(fd, &stat); + if (ret < 0) + return -errno; + + ret = load_xbc_fd(fd, buf, stat.st_size); + + close(fd); + + return ret; +} + +int load_xbc_from_initrd(int fd, char **buf) +{ + struct stat stat; + int ret; + u32 size = 0, csum = 0, rcsum; + + ret = fstat(fd, &stat); + if (ret < 0) + return -errno; + + if (stat.st_size < 8) + return 0; + + if (lseek(fd, -8, SEEK_END) < 0) { + printf("Failed to lseek: %d\n", -errno); + return -errno; + } + + if (read(fd, &size, sizeof(u32)) < 0) + return -errno; + + if (read(fd, &csum, sizeof(u32)) < 0) + return -errno; + + /* Wrong size, maybe no boot config here */ + if (stat.st_size < size + 8) + return 0; + + if (lseek(fd, stat.st_size - 8 - size, SEEK_SET) < 0) { + printf("Failed to lseek: %d\n", -errno); + return -errno; + } + + ret = load_xbc_fd(fd, buf, size); + if (ret < 0) + return ret; + + /* Wrong Checksum, maybe no boot config here */ + rcsum = checksum((unsigned char *)*buf, size); + if (csum != rcsum) { + printf("checksum error: %d != %d\n", csum, rcsum); + return 0; + } + + ret = xbc_init(*buf); + /* Wrong data, maybe no boot config here */ + if (ret < 0) + return 0; + + return size; +} + +int show_xbc(const char *path) +{ + int ret, fd; + char *buf = NULL; + + fd = open(path, O_RDONLY); + if (fd < 0) { + printf("Failed to open initrd %s: %d\n", path, fd); + return -errno; + } + + ret = load_xbc_from_initrd(fd, &buf); + if (ret < 0) + printf("Failed to load a boot config from initrd: %d\n", ret); + else + xbc_show_compact_tree(); + + close(fd); + free(buf); + + return ret; +} + +int delete_xbc(const char *path) +{ + struct stat stat; + int ret = 0, fd, size; + char *buf = NULL; + + fd = open(path, O_RDWR); + if (fd < 0) { + printf("Failed to open initrd %s: %d\n", path, fd); + return -errno; + } + + /* + * Suppress error messages in xbc_init() because it can be just a + * data which concidentally matches the size and checksum footer. + */ + pr_output = 0; + size = load_xbc_from_initrd(fd, &buf); + pr_output = 1; + if (size < 0) { + ret = size; + printf("Failed to load a boot config from initrd: %d\n", ret); + } else if (size > 0) { + ret = fstat(fd, &stat); + if (!ret) + ret = ftruncate(fd, stat.st_size - size - 8); + if (ret) + ret = -errno; + } /* Ignore if there is no boot config in initrd */ + + close(fd); + free(buf); + + return ret; +} + +int apply_xbc(const char *path, const char *xbc_path) +{ + u32 size, csum; + char *buf, *data; + int ret, fd; + + ret = load_xbc_file(xbc_path, &buf); + if (ret < 0) { + printf("Failed to load %s : %d\n", xbc_path, ret); + return ret; + } + size = strlen(buf) + 1; + csum = checksum((unsigned char *)buf, size); + + /* Prepare xbc_path data */ + data = malloc(size + 8); + if (!data) + return -ENOMEM; + strcpy(data, buf); + *(u32 *)(data + size) = size; + *(u32 *)(data + size + 4) = csum; + + /* Check the data format */ + ret = xbc_init(buf); + if (ret < 0) { + printf("Failed to parse %s: %d\n", xbc_path, ret); + free(data); + free(buf); + return ret; + } + printf("Apply %s to %s\n", xbc_path, path); + printf("\tNumber of nodes: %d\n", ret); + printf("\tSize: %u bytes\n", (unsigned int)size); + printf("\tChecksum: %d\n", (unsigned int)csum); + + /* TODO: Check the options by schema */ + xbc_destroy_all(); + free(buf); + + /* Remove old boot config if exists */ + ret = delete_xbc(path); + if (ret < 0) { + printf("Failed to delete previous boot config: %d\n", ret); + return ret; + } + + /* Apply new one */ + fd = open(path, O_RDWR | O_APPEND); + if (fd < 0) { + printf("Failed to open %s: %d\n", path, fd); + return fd; + } + /* TODO: Ensure the @path is initramfs/initrd image */ + ret = write(fd, data, size + 8); + if (ret < 0) { + printf("Failed to apply a boot config: %d\n", ret); + return ret; + } + close(fd); + free(data); + + return 0; +} + +int usage(void) +{ + printf("Usage: bootconfig [OPTIONS] <INITRD>\n" + " Apply, delete or show boot config to initrd.\n" + " Options:\n" + " -a <config>: Apply boot config to initrd\n" + " -d : Delete boot config file from initrd\n\n" + " If no option is given, show current applied boot config.\n"); + return -1; +} + +int main(int argc, char **argv) +{ + char *path = NULL; + char *apply = NULL; + bool delete = false; + int opt; + + while ((opt = getopt(argc, argv, "hda:")) != -1) { + switch (opt) { + case 'd': + delete = true; + break; + case 'a': + apply = optarg; + break; + case 'h': + default: + return usage(); + } + } + + if (apply && delete) { + printf("Error: You can not specify both -a and -d at once.\n"); + return usage(); + } + + if (optind >= argc) { + printf("Error: No initrd is specified.\n"); + return usage(); + } + + path = argv[optind]; + + if (apply) + return apply_xbc(path, apply); + else if (delete) + return delete_xbc(path); + + return show_xbc(path); +} |