On Thu, Jul 11, 2019 at 01:24:29AM +0530, Bhupesh Sharma wrote:
> Currently the kexec_file_load() support for arm64 doesn't allow
> handling zlib compressed (i.e. Image.gz) image.
>
> Since most distributions use 'make zinstall' rule inside
> 'arch/arm64/boot/Makefile' to install the arm64
> Image.gz compressed file inside the boot destination directory (for e.g.
> /boot), currently we cannot use kexec_file_load() to load vmlinuz (or
> Image.gz):
>
> # file /boot/vmlinuz
> /boot/vmlinuz: gzip compressed data, was "Image", <..snip..>, max
> compression, from Unix, original size 21945120
>
> Now, since via kexec_file_load() we pass the 'fd' of Image.gz
> (compressed file) via the following command line ...
>
> # kexec -s -l /boot/vmlinuz-`uname -r` --initrd=/boot/initramfs-`uname
> -r`.img --reuse-cmdline
>
> ... kernel returns -EINVAL error value, as it is not able to locate
> the magic number =0x644d5241, which is expected in the 64-byte header
> of the decompressed kernel image.
>
> We can fix this in user-space kexec-tools, which handles an
> 'Image.gz' being passed via kexec_file_load(), using an approach
> as follows:
>
> a). Copy the contents of Image.gz to a temporary file.
> b). Decompress (gunzip-decompress) the contents inside the
> temporary file.
> c). Pass the 'fd' of the temporary file to the kernel space. So
> basically the kernel space still gets a decompressed kernel
> image to load via kexec-tools
>
> I tested this patch for the following three use-cases:
>
> 1. Uncompressed Image file:
> #kexec -s -l Image --initrd=/boot/initramfs-`uname -r`.img --reuse-cmdline
>
> 2. Signed Image file:
> #kexec -s -l Image.signed --initrd=/boot/initramfs-`uname -r`.img --reuse-cmdline
>
> 3. zlib compressed Image.gz file:
> #kexec -s -l /boot/vmlinuz-`uname -r` --initrd=/boot/initramfs-`uname -r`.img --reuse-cmdline
>
> Signed-off-by: Bhupesh Sharma <bhsharma@xxxxxxxxxx>
> ---
> kexec/arch/arm64/Makefile | 3 +-
> kexec/arch/arm64/kexec-arm64.c | 1 +
> kexec/arch/arm64/kexec-arm64.h | 7 ++
> kexec/arch/arm64/kexec-image-arm64.c | 4 +-
> kexec/arch/arm64/kexec-zImage-arm64.c | 199 ++++++++++++++++++++++++++++++++++
> kexec/kexec.c | 12 ++
> 6 files changed, 223 insertions(+), 3 deletions(-)
> create mode 100644 kexec/arch/arm64/kexec-zImage-arm64.c
>
> diff --git a/kexec/arch/arm64/Makefile b/kexec/arch/arm64/Makefile
> index 9d9111caa8ed..d27c8ee1b5e7 100644
> --- a/kexec/arch/arm64/Makefile
> +++ b/kexec/arch/arm64/Makefile
> @@ -15,7 +15,8 @@ arm64_KEXEC_SRCS += \
> kexec/arch/arm64/kexec-arm64.c \
> kexec/arch/arm64/kexec-elf-arm64.c \
> kexec/arch/arm64/kexec-uImage-arm64.c \
> - kexec/arch/arm64/kexec-image-arm64.c
> + kexec/arch/arm64/kexec-image-arm64.c \
> + kexec/arch/arm64/kexec-zImage-arm64.c
>
> arm64_UIMAGE = kexec/kexec-uImage.c
>
> diff --git a/kexec/arch/arm64/kexec-arm64.c b/kexec/arch/arm64/kexec-arm64.c
> index 2992bce8139f..eb3a3a37307c 100644
> --- a/kexec/arch/arm64/kexec-arm64.c
> +++ b/kexec/arch/arm64/kexec-arm64.c
> @@ -71,6 +71,7 @@ struct file_type file_type[] = {
> {"vmlinux", elf_arm64_probe, elf_arm64_load, elf_arm64_usage},
> {"Image", image_arm64_probe, image_arm64_load, image_arm64_usage},
> {"uImage", uImage_arm64_probe, uImage_arm64_load, uImage_arm64_usage},
> + {"zImage", zImage_arm64_probe, zImage_arm64_load, zImage_arm64_usage},
> };
>
> int file_types = sizeof(file_type) / sizeof(file_type[0]);
> diff --git a/kexec/arch/arm64/kexec-arm64.h b/kexec/arch/arm64/kexec-arm64.h
> index cc3419f4c10f..628de79b7f70 100644
> --- a/kexec/arch/arm64/kexec-arm64.h
> +++ b/kexec/arch/arm64/kexec-arm64.h
> @@ -38,11 +38,18 @@ int image_arm64_probe(const char *kernel_buf, off_t kernel_size);
> int image_arm64_load(int argc, char **argv, const char *kernel_buf,
> off_t kernel_size, struct kexec_info *info);
> void image_arm64_usage(void);
> +
> int uImage_arm64_probe(const char *buf, off_t len);
> int uImage_arm64_load(int argc, char **argv, const char *buf, off_t len,
> struct kexec_info *info);
> void uImage_arm64_usage(void);
>
> +int zImage_arm64_probe(const char *kernel_buf, off_t kernel_size);
> +int zImage_arm64_load(int argc, char **argv, const char *kernel_buf,
> + off_t kernel_size, struct kexec_info *info);
> +void zImage_arm64_usage(void);
> +
> +
> off_t initrd_base;
> off_t initrd_size;
>
> diff --git a/kexec/arch/arm64/kexec-image-arm64.c b/kexec/arch/arm64/kexec-image-arm64.c
> index 685a99352e39..aa8f2e22d72b 100644
> --- a/kexec/arch/arm64/kexec-image-arm64.c
> +++ b/kexec/arch/arm64/kexec-image-arm64.c
> @@ -114,6 +114,6 @@ exit:
> void image_arm64_usage(void)
> {
> printf(
> -" An ARM64 binary image, compressed or not, big or little endian.\n"
> -" Typically an Image, Image.gz or Image.lzma file.\n\n");
> +" An ARM64 binary image, uncompressed, big or little endian.\n"
> +" Typically an Image file.\n\n");
> }
> diff --git a/kexec/arch/arm64/kexec-zImage-arm64.c b/kexec/arch/arm64/kexec-zImage-arm64.c
> new file mode 100644
> index 000000000000..2b83ef6bdffd
> --- /dev/null
> +++ b/kexec/arch/arm64/kexec-zImage-arm64.c
> @@ -0,0 +1,199 @@
> +/*
> + * ARM64 kexec zImage (Image.gz) support.
> + *
> + * Several distros use 'make zinstall' rule inside
> + * 'arch/arm64/boot/Makefile' to install the arm64
> + * Image.gz compressed file inside the boot destination
> + * directory (for e.g. /boot).
> + *
> + * Currently we cannot use kexec_file_load() to load vmlinuz
> + * (or Image.gz).
> + *
> + * To support Image.gz, we should:
> + * a). Copy the contents of Image.gz to a temporary file.
> + * b). Decompress (gunzip-decompress) the contents inside the
> + * temporary file.
> + * c). Pass the 'fd' of the temporary file to the kernel space.
> + *
> + * So basically the kernel space still gets a decompressed
> + * kernel image to load via kexec-tools.
> + */
> +
> +#define _GNU_SOURCE
> +
> +#include <errno.h>
> +#include <fcntl.h>
> +#include <limits.h>
> +#include <stdlib.h>
> +#include "crashdump-arm64.h"
> +#include "image-header.h"
> +#include "kexec.h"
> +#include "kexec-arm64.h"
> +#include "kexec-syscall.h"
> +#include "kexec-zlib.h"
> +#include "arch/options.h"
> +
> +#define FILENAME_IMAGE "/tmp/ImageXXXXXX"
> +
> +/* Returns:
> + * -1 : in case of error/invalid format (not a valid Image.gz format.
> + * fd: File descriptor of the temp file containing the decompressed
> + * Image.
> + */
> +int zImage_arm64_probe(const char *kernel_buf, off_t kernel_size)
> +{
> + int kernel_fd = 0;
> + char *fname = NULL;
> + char *kernel_uncompressed_buf = NULL;
> + const struct arm64_image_header *h;
> +
> + if (!is_zlib_file(kernel_buf, &kernel_size)) {
> + dbgprintf("%s: Not an zImage file (Image.gz).\n", __func__);
> + return -1;
> + }
> +
> + if (!(fname = strdup(FILENAME_IMAGE))) {
> + dbgprintf("%s: Can't duplicate strings %s\n", __func__,
> + fname);
> + return -1;
> + }
> +
> + if ((kernel_fd = mkstemp(fname)) < 0) {
> + dbgprintf("%s: Can't open file %s\n", __func__,
> + fname);
> + return -1;
> + }
> +
> + kernel_uncompressed_buf =
> + (char *) calloc(kernel_size, sizeof(off_t));
> + if (!kernel_uncompressed_buf) {
> + dbgprintf("%s: Can't calloc %ld bytes\n",
> + __func__, kernel_size);
> + return -ENOMEM;
> + }
> +
> + /* slurp in the input kernel */
> + dbgprintf("%s: ", __func__);
> + kernel_uncompressed_buf = slurp_decompress_file(kernel_buf,
> + &kernel_size);
> +
> + /* check for correct header magic */
> + if (kernel_size < sizeof(struct arm64_image_header)) {
> + dbgprintf("%s: No arm64 image header.\n", __func__);
> + return -1;
> + }
> +
> + h = (const struct arm64_image_header *)(kernel_uncompressed_buf);
> +
> + if (!arm64_header_check_magic(h)) {
> + dbgprintf("%s: Bad arm64 image header.\n", __func__);
> + return -1;
> + }
> +
> + if (write(kernel_fd, kernel_uncompressed_buf,
> + kernel_size) != kernel_size) {
> + dbgprintf("%s: Can't write the uncompressed file %s\n",
> + __func__, fname);
> + return -1;
> + }
I think that kernel_fd needs to also be closed in
error cases to avoid a leak.
> +
> + close(kernel_fd);
What if the contents of the file whose name is fdname is replaced at this
moment?
> +
> + /* Open the tmp file again, this time in O_RDONLY mode, as
> + * opening the file in O_RDWR and calling kexec_file_load()
> + * causes the kernel to return -ETXTBSY
> + */
> + kernel_fd = open(fname, O_RDONLY);
> + if (kernel_fd == -1) {
> + dbgprintf("%s: Failed to open file %s\n",
> + __func__, fname);
> + return -1;
> + }
I think that fname is leaked here and in error cases.
> +
> + return kernel_fd;
> +}
> +
> +int zImage_arm64_load(int argc, char **argv, const char *kernel_buf,
> + off_t kernel_size, struct kexec_info *info)
> +{
> + const struct arm64_image_header *header;
> + unsigned long kernel_segment;
> + int result;
> +
> + if (info->file_mode) {
> + if (arm64_opts.initrd) {
> + info->initrd_fd = open(arm64_opts.initrd, O_RDONLY);
> + if (info->initrd_fd == -1) {
> + fprintf(stderr,
> + "Could not open initrd file %s:%s\n",
> + arm64_opts.initrd, strerror(errno));
> + result = EFAILED;
> + goto exit;
> + }
> + }
> +
> + if (arm64_opts.command_line) {
> + info->command_line = (char *)arm64_opts.command_line;
> + info->command_line_len =
> + strlen(arm64_opts.command_line) + 1;
> + }
> +
> + return 0;
> + }
> +
> + header = (const struct arm64_image_header *)(kernel_buf);
> +
> + if (arm64_process_image_header(header))
> + return EFAILED;
> +
> + kernel_segment = arm64_locate_kernel_segment(info);
> +
> + if (kernel_segment == ULONG_MAX) {
> + dbgprintf("%s: Kernel segment is not allocated\n", __func__);
> + result = EFAILED;
> + goto exit;
> + }
> +
> + dbgprintf("%s: kernel_segment: %016lx\n", __func__, kernel_segment);
> + dbgprintf("%s: text_offset: %016lx\n", __func__,
> + arm64_mem.text_offset);
> + dbgprintf("%s: image_size: %016lx\n", __func__,
> + arm64_mem.image_size);
> + dbgprintf("%s: phys_offset: %016lx\n", __func__,
> + arm64_mem.phys_offset);
> + dbgprintf("%s: vp_offset: %016lx\n", __func__,
> + arm64_mem.vp_offset);
> + dbgprintf("%s: PE format: %s\n", __func__,
> + (arm64_header_check_pe_sig(header) ? "yes" : "no"));
> +
> + /* create and initialize elf core header segment */
> + if (info->kexec_flags & KEXEC_ON_CRASH) {
> + result = load_crashdump_segments(info);
> + if (result) {
> + dbgprintf("%s: Creating eflcorehdr failed.\n",
> + __func__);
> + goto exit;
> + }
> + }
> +
> + /* load the kernel */
> + add_segment_phys_virt(info, kernel_buf, kernel_size,
> + kernel_segment + arm64_mem.text_offset,
> + arm64_mem.image_size, 0);
> +
> + /* load additional data */
> + result = arm64_load_other_segments(info, kernel_segment
> + + arm64_mem.text_offset);
> +
> +exit:
> + if (result)
> + fprintf(stderr, "kexec: load failed.\n");
> + return result;
> +}
> +
> +void zImage_arm64_usage(void)
> +{
> + printf(
> +" An ARM64 zImage, compressed, big or little endian.\n"
> +" Typically an Image.gz or Image.lzma file.\n\n");
> +}
> diff --git a/kexec/kexec.c b/kexec/kexec.c
> index 8ca3b457cac8..bc6ab3dbd10b 100644
> --- a/kexec/kexec.c
> +++ b/kexec/kexec.c
> @@ -1206,8 +1206,20 @@ static int do_kexec_file_load(int fileind, int argc, char **argv,
> kernel_buf = slurp_decompress_file(kernel, &kernel_size);
>
> for (i = 0; i < file_types; i++) {
> +#ifdef __aarch64__
> + /* handle Image.gz like cases */
> + if (is_zlib_file(kernel, &kernel_size)) {
> + if ((ret = file_type[i].probe(kernel, kernel_size)) >= 0) {
> + kernel_fd = ret;
> + break;
> + }
> + } else
> + if (file_type[i].probe(kernel_buf, kernel_size) >= 0)
> + break;
> +#else
> if (file_type[i].probe(kernel_buf, kernel_size) >= 0)
> break;
> +#endif
> }
>
> if (i == file_types) {
> --
> 2.7.4
>
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