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tools/bootconfig: Align the bootconfig applied initrd image size to 4

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Align the bootconfig applied initrd image size to 4. To fill the gap,
the bootconfig command uses null characters in between the bootconfig
data and the footer. This will expands the footer size but don't change
the checksum.
Thus the block image of the initrd file with bootconfig is as follows.

[initrd][bootconfig][(pad)][size][csum]["#BOOTCONFIG\n"]

Link: https://lkml.kernel.org/r/160576522046.320071.8550680670010950634.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
This commit is contained in:
Masami Hiramatsu 2020-11-19 14:53:40 +09:00 committed by Steven Rostedt (VMware)
parent a995e6bc05
commit e1cef2d4c3
3 changed files with 43 additions and 25 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
include/linux/bootconfig.h
View File

@ -12,6 +12,9 @@
#define BOOTCONFIG_MAGIC "#BOOTCONFIG\n"
#define BOOTCONFIG_MAGIC_LEN 12
#define BOOTCONFIG_ALIGN_SHIFT 2
#define BOOTCONFIG_ALIGN (1 << BOOTCONFIG_ALIGN_SHIFT)
#define BOOTCONFIG_ALIGN_MASK (BOOTCONFIG_ALIGN - 1)
/* XBC tree node */
struct xbc_node {

59
tools/bootconfig/main.c
View File

@ -337,12 +337,13 @@ static int delete_xbc(const char *path)
static int apply_xbc(const char *path, const char *xbc_path)
{
char *buf, *data, *p;
size_t total_size;
struct stat stat;
u32 size, csum;
char *buf, *data;
int ret, fd;
const char *msg;
int pos;
u32 size, csum;
int pos, pad;
int ret, fd;
ret = load_xbc_file(xbc_path, &buf);
if (ret < 0) {
@ -352,13 +353,12 @@ static int apply_xbc(const char *path, const char *xbc_path)
size = strlen(buf) + 1;
csum = checksum((unsigned char *)buf, size);
/* Prepare xbc_path data */
data = malloc(size + 8);
/* Backup the bootconfig data */
data = calloc(size + BOOTCONFIG_ALIGN +
sizeof(u32) + sizeof(u32) + BOOTCONFIG_MAGIC_LEN, 1);
if (!data)
return -ENOMEM;
strcpy(data, buf);
*(u32 *)(data + size) = size;
*(u32 *)(data + size + 4) = csum;
memcpy(data, buf, size);
/* Check the data format */
ret = xbc_init(buf, &msg, &pos);
@ -399,24 +399,35 @@ static int apply_xbc(const char *path, const char *xbc_path)
pr_err("Failed to get the size of %s\n", path);
goto out;
}
ret = write(fd, data, size + 8);
if (ret < size + 8) {
/* To align up the total size to BOOTCONFIG_ALIGN, get padding size */
total_size = stat.st_size + size + sizeof(u32) * 2 + BOOTCONFIG_MAGIC_LEN;
pad = ((total_size + BOOTCONFIG_ALIGN - 1) & (~BOOTCONFIG_ALIGN_MASK)) - total_size;
size += pad;
/* Add a footer */
p = data + size;
*(u32 *)p = size;
p += sizeof(u32);
*(u32 *)p = csum;
p += sizeof(u32);
memcpy(p, BOOTCONFIG_MAGIC, BOOTCONFIG_MAGIC_LEN);
p += BOOTCONFIG_MAGIC_LEN;
total_size = p - data;
ret = write(fd, data, total_size);
if (ret < total_size) {
if (ret < 0)
ret = -errno;
pr_err("Failed to apply a boot config: %d\n", ret);
if (ret < 0)
goto out;
goto out_rollback;
}
/* Write a magic word of the bootconfig */
ret = write(fd, BOOTCONFIG_MAGIC, BOOTCONFIG_MAGIC_LEN);
if (ret < BOOTCONFIG_MAGIC_LEN) {
if (ret < 0)
ret = -errno;
pr_err("Failed to apply a boot config magic: %d\n", ret);
goto out_rollback;
}
ret = 0;
if (ret >= 0)
goto out_rollback;
} else
ret = 0;
out:
close(fd);
free(data);

6
tools/bootconfig/test-bootconfig.sh
View File

@ -9,6 +9,7 @@ else
TESTDIR=.
fi
BOOTCONF=${TESTDIR}/bootconfig
ALIGN=4
INITRD=`mktemp ${TESTDIR}/initrd-XXXX`
TEMPCONF=`mktemp ${TESTDIR}/temp-XXXX.bconf`
@ -59,7 +60,10 @@ echo "Show command test"
xpass $BOOTCONF $INITRD
echo "File size check"
xpass test $new_size -eq $(expr $bconf_size + $initrd_size + 9 + 12)
total_size=$(expr $bconf_size + $initrd_size + 9 + 12 + $ALIGN - 1 )
total_size=$(expr $total_size / $ALIGN)
total_size=$(expr $total_size \* $ALIGN)
xpass test $new_size -eq $total_size
echo "Apply command repeat test"
xpass $BOOTCONF -a $TEMPCONF $INITRD