Hi Simon,
Thanks for your review.
On Thu, Jul 11, 2019 at 3:38 PM Simon Horman <horms@xxxxxxxxxxxx> wrote:
>
> 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.
Right.
> > +
> > + close(kernel_fd);
>
> What if the contents of the file whose name is fdname is replaced at this
> moment?
Normally that wouldn't happen, but I will check this more carefully
and fix in v2.
> > +
> > + /* 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.
Right. Will fix this in v2.
Thanks,
Bhupesh
> > +
> > + 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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