[PATCHv7 1/5] kexec/arm64: Simplify the code for zImage
Pingfan Liu
piliu at redhat.com
Wed Aug 2 19:41:48 PDT 2023
Inside zimage_probe(), it uncompresses the kernel and performs some
check, similar to image_probe(). Taking a close look, the uncompressing
has already executed before the image probe is called. What is missing
here is to provide a fd, pointing to an uncompressed kernel image.
This patch creates a memfd based on the result produced by
slurp_decompress_file(), and finally simplify the logical of the probe
for aarch64.
The credit goes to the Dave Young, who contributes the original code.
Signed-off-by: Pingfan Liu <piliu at redhat.com>
Co-authored-by: Dave Young <dyoung at redhat.com>
To: kexec at lists.infradead.org
Cc: horms at verge.net.au
Cc: ardb at kernel.org
Cc: jeremy.linton at arm.com
---
kexec/arch/arm64/Makefile | 3 +-
kexec/arch/arm64/kexec-arm64.c | 1 -
kexec/arch/arm64/kexec-arm64.h | 6 -
kexec/arch/arm64/kexec-image-arm64.c | 2 +-
kexec/arch/arm64/kexec-zImage-arm64.c | 226 --------------------------
kexec/kexec.c | 42 +++--
6 files changed, 26 insertions(+), 254 deletions(-)
delete mode 100644 kexec/arch/arm64/kexec-zImage-arm64.c
diff --git a/kexec/arch/arm64/Makefile b/kexec/arch/arm64/Makefile
index d27c8ee..9d9111c 100644
--- a/kexec/arch/arm64/Makefile
+++ b/kexec/arch/arm64/Makefile
@@ -15,8 +15,7 @@ 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-zImage-arm64.c
+ kexec/arch/arm64/kexec-image-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 ec6df4b..a830ec7 100644
--- a/kexec/arch/arm64/kexec-arm64.c
+++ b/kexec/arch/arm64/kexec-arm64.c
@@ -74,7 +74,6 @@ 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 5eb9fc0..d29b1b3 100644
--- a/kexec/arch/arm64/kexec-arm64.h
+++ b/kexec/arch/arm64/kexec-arm64.h
@@ -44,12 +44,6 @@ 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);
-
-
extern off_t initrd_base;
extern off_t initrd_size;
diff --git a/kexec/arch/arm64/kexec-image-arm64.c b/kexec/arch/arm64/kexec-image-arm64.c
index aa8f2e2..a196747 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, uncompressed, big or little endian.\n"
+" An ARM64 binary image, compressed or not, 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
deleted file mode 100644
index 6ee82ff..0000000
--- a/kexec/arch/arm64/kexec-zImage-arm64.c
+++ /dev/null
@@ -1,226 +0,0 @@
-/*
- * 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 ret = -1;
- int fd = 0;
- 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 ((fd = mkstemp(fname)) < 0) {
- dbgprintf("%s: Can't open file %s\n", __func__,
- fname);
- ret = -1;
- goto fail_mkstemp;
- }
-
- 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);
- ret= -ENOMEM;
- goto fail_calloc;
- }
-
- /* 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__);
- ret = -1;
- goto fail_bad_header;
- }
-
- h = (const struct arm64_image_header *)(kernel_uncompressed_buf);
-
- if (!arm64_header_check_magic(h)) {
- dbgprintf("%s: Bad arm64 image header.\n", __func__);
- ret = -1;
- goto fail_bad_header;
- }
-
- if (write(fd, kernel_uncompressed_buf,
- kernel_size) != kernel_size) {
- dbgprintf("%s: Can't write the uncompressed file %s\n",
- __func__, fname);
- ret = -1;
- goto fail_bad_header;
- }
-
- close(fd);
-
- /* 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);
- ret = -1;
- goto fail_bad_header;
- }
-
- unlink(fname);
-
- free(kernel_uncompressed_buf);
- free(fname);
-
- return kernel_fd;
-
-fail_bad_header:
- free(kernel_uncompressed_buf);
-
-fail_calloc:
- if (fd >= 0)
- close(fd);
-
- unlink(fname);
-
-fail_mkstemp:
- free(fname);
-
- return ret;
-}
-
-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 36bb2ad..d132eb5 100644
--- a/kexec/kexec.c
+++ b/kexec/kexec.c
@@ -638,6 +638,21 @@ char *slurp_decompress_file(const char *filename, off_t *r_size)
return kernel_buf;
}
+static int copybuf_memfd(const char *kernel_buf, size_t size)
+{
+ int fd, count;
+
+ fd = memfd_create("kernel", MFD_ALLOW_SEALING);
+ if (fd == -1)
+ return fd;
+
+ count = write(fd, kernel_buf, size);
+ if (count < 0)
+ return -1;
+
+ return fd;
+}
+
static void update_purgatory(struct kexec_info *info)
{
static const uint8_t null_buf[256];
@@ -1290,31 +1305,22 @@ static int do_kexec_file_load(int fileind, int argc, char **argv,
kernel = argv[fileind];
- kernel_fd = open(kernel, O_RDONLY);
- if (kernel_fd == -1) {
- fprintf(stderr, "Failed to open file %s:%s\n", kernel,
+ /* slurp in the input kernel */
+ kernel_buf = slurp_decompress_file(kernel, &kernel_size);
+ if (!kernel_buf) {
+ fprintf(stderr, "Failed to decompress file %s:%s\n", kernel,
strerror(errno));
return EFAILED;
}
-
- /* slurp in the input kernel */
- kernel_buf = slurp_decompress_file(kernel, &kernel_size);
+ kernel_fd = copybuf_memfd(kernel_buf, kernel_size);
+ if (kernel_fd < 0) {
+ fprintf(stderr, "Failed to copy decompressed buf\n");
+ return EFAILED;
+ }
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) {
--
2.31.1
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