[PATCH 0/4] kexec/arm64: Add support for zlib compressed kernel images (Image.gz)

[PATCH 0/4] kexec/arm64: Add support for zlib compressed kernel images (Image.gz)

[Bhupesh Sharma]

This patchset adds the support for zlib compressed kernel images
(Image.gz) for arm64 kexec-tools.

This was discussed a bit with the arm64 kernel maintainers (see [0]) and
after discussing the pros and cons of adding this support in
kernel-space v/s in user-space, we decided it makes more sense to add
this support to the user-space kexec-tools.

Note that this series adds support for unsigned arm64 Image.gz files
only as signing an Image.gz type file is not a easy implementation from
kexec-tools p-o-v. Also even standard signing tools like sbsign fail to
recongize the Image.gz format:

 $ sbsign --key certs/signing_key.pem  --cert certs/signing_key.pem Image.gz
   Invalid DOS header magic

... because that gzip file isn't a PE32+ that can be loaded by UEFI.
So I will work on the same in coming days and try to send a RFC
patchset for the same later on.

[0]. http://lists.infradead.org/pipermail/kexec/2019-June/023156.html

Bhupesh Sharma (4):
  kexec/kexec.c: Add the missing close() for fd used for
    kexec_file_load()
  kexec-uImage-arm64.c: Fix return value of uImage_arm64_probe()
  kexec/kexec-zlib.h: Add 'is_zlib_file()' helper function
  kexec/arm64: Add support for handling zlib compressed (Image.gz) image

 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-uImage-arm64.c |  13 ++-
 kexec/arch/arm64/kexec-zImage-arm64.c | 199 ++++++++++++++++++++++++++++++++++
 kexec/kexec-zlib.h                    |   1 +
 kexec/kexec.c                         |  14 +++
 kexec/zlib.c                          |  32 ++++++
 9 files changed, 270 insertions(+), 4 deletions(-)
 create mode 100644 kexec/arch/arm64/kexec-zImage-arm64.c

-- 
2.7.4


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[PATCH 1/4] kexec/kexec.c: Add the missing close() for fd used for kexec_file_load()

[Bhupesh Sharma]

In kexec/kexec.c, we open() the kernel Image file and pass this file
descriptor to the kexec_file_load() system call, but never call a
corresponding close().

Fix the same via this patch.

Signed-off-by: Bhupesh Sharma <bhsharma@redhat.com>
---
 kexec/kexec.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/kexec/kexec.c b/kexec/kexec.c
index 32ae56c8f1c3..8ca3b457cac8 100644
--- a/kexec/kexec.c
+++ b/kexec/kexec.c
@@ -1234,6 +1234,8 @@ static int do_kexec_file_load(int fileind, int argc, char **argv,
 	if (ret != 0)
 		fprintf(stderr, "kexec_file_load failed: %s\n",
 					strerror(errno));
+
+	close(kernel_fd);
 	return ret;
 }
 
-- 
2.7.4


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[PATCH 2/4] kexec-uImage-arm64.c: Fix return value of uImage_arm64_probe()

[Bhupesh Sharma]

Commit bf06cf2095e1 ("kexec/uImage: probe to identify a corrupted image"),
defined the 'uImage_probe_kernel()' function return values and
correspondingly ;uImage_arm64_probe()' returns the same (0 -> If the
image is valid 'type' image, -1 -> If the image is corrupted and
1 -> If the image is not a uImage).

This causes issues because, in later patches we introduce zImage
support for arm64, and since it is probed after uImage, the return
values from 'uImage_arm64_probe()' needs to be fixed to make sure
that kexec will not return with an invalid error code.

Now, 'uImage_arm64_probe()' returns the following values instead:
  0 - valid uImage.
 -1 - uImage is corrupted.
  1 - image is not a uImage.

Signed-off-by: Bhupesh Sharma <bhsharma@redhat.com>
---
 kexec/arch/arm64/kexec-uImage-arm64.c | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/kexec/arch/arm64/kexec-uImage-arm64.c b/kexec/arch/arm64/kexec-uImage-arm64.c
index 126ea9c2555b..c4669131b667 100644
--- a/kexec/arch/arm64/kexec-uImage-arm64.c
+++ b/kexec/arch/arm64/kexec-uImage-arm64.c
@@ -11,7 +11,18 @@
 
 int uImage_arm64_probe(const char *buf, off_t len)
 {
-	return uImage_probe_kernel(buf, len, IH_ARCH_ARM64);
+	int ret;
+
+	ret = uImage_probe_kernel(buf, len, IH_ARCH_ARM64);
+
+	/*  0 - valid uImage.
+	 * -1 - uImage is corrupted.
+	 *  1 - image is not a uImage.
+	 */
+	if (!ret)
+		return 0;
+	else
+		return -1;
 }
 
 int uImage_arm64_load(int argc, char **argv, const char *buf, off_t len,
-- 
2.7.4


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[PATCH 3/4] kexec/kexec-zlib.h: Add 'is_zlib_file()' helper function

[Bhupesh Sharma]

This patch adds 'is_zlib_file()' helper function which can be
used to quickly determine with the passed kernel image is a zlib
compressed kernel image.

This is specifically useful for arm64 zImage (or Image.gz) support,
which is introduced by later patches in this patchset.

Signed-off-by: Bhupesh Sharma <bhsharma@redhat.com>
---
 kexec/kexec-zlib.h |  1 +
 kexec/zlib.c       | 32 ++++++++++++++++++++++++++++++++
 2 files changed, 33 insertions(+)

diff --git a/kexec/kexec-zlib.h b/kexec/kexec-zlib.h
index 43c107bf4a72..16300f294759 100644
--- a/kexec/kexec-zlib.h
+++ b/kexec/kexec-zlib.h
@@ -6,5 +6,6 @@
 
 #include "config.h"
 
+int is_zlib_file(const char *filename, off_t *r_size);
 char *zlib_decompress_file(const char *filename, off_t *r_size);
 #endif /* __KEXEC_ZLIB_H */
diff --git a/kexec/zlib.c b/kexec/zlib.c
index 95b608059d41..34d5ca566769 100644
--- a/kexec/zlib.c
+++ b/kexec/zlib.c
@@ -23,6 +23,32 @@ static void _gzerror(gzFile fp, int *errnum, const char **errmsg)
 	}
 }
 
+int is_zlib_file(const char *filename, off_t *r_size)
+{
+	gzFile fp;
+	int errnum;
+	const char *msg;
+
+	if (!filename)
+		goto out;
+
+	fp = gzopen(filename, "rb");
+	if (fp == 0) {
+		_gzerror(fp, &errnum, &msg);
+		dbgprintf("Cannot open `%s': %s\n", filename, msg);
+		goto out;
+	}
+
+	if (gzdirect(fp))
+		/* It's not in gzip format */
+		goto out;
+
+	/* It's in gzip format */
+	return 1;
+out:
+	return 0;
+}
+
 char *zlib_decompress_file(const char *filename, off_t *r_size)
 {
 	gzFile fp;
@@ -84,6 +110,12 @@ fail:
 	return buf;
 }
 #else
+
+int is_zlib_file(const char *filename, off_t *r_size)
+{
+	return 0;
+}
+
 char *zlib_decompress_file(const char *UNUSED(filename), off_t *UNUSED(r_size))
 {
 	return NULL;
-- 
2.7.4


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[PATCH 4/4] kexec/arm64: Add support for handling zlib compressed (Image.gz) image

[Bhupesh Sharma]

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@redhat.com>
---
 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;
+	}
+
+	close(kernel_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);
+		return -1;
+	}
+
+	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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Re: [PATCH 3/4] kexec/kexec-zlib.h: Add 'is_zlib_file()' helper function

[Simon Horman]

On Thu, Jul 11, 2019 at 01:24:28AM +0530, Bhupesh Sharma wrote:
> This patch adds 'is_zlib_file()' helper function which can be
> used to quickly determine with the passed kernel image is a zlib
> compressed kernel image.
> 
> This is specifically useful for arm64 zImage (or Image.gz) support,
> which is introduced by later patches in this patchset.
> 
> Signed-off-by: Bhupesh Sharma <bhsharma@redhat.com>
> ---
>  kexec/kexec-zlib.h |  1 +
>  kexec/zlib.c       | 32 ++++++++++++++++++++++++++++++++
>  2 files changed, 33 insertions(+)
> 
> diff --git a/kexec/kexec-zlib.h b/kexec/kexec-zlib.h
> index 43c107bf4a72..16300f294759 100644
> --- a/kexec/kexec-zlib.h
> +++ b/kexec/kexec-zlib.h
> @@ -6,5 +6,6 @@
>  
>  #include "config.h"
>  
> +int is_zlib_file(const char *filename, off_t *r_size);
>  char *zlib_decompress_file(const char *filename, off_t *r_size);
>  #endif /* __KEXEC_ZLIB_H */
> diff --git a/kexec/zlib.c b/kexec/zlib.c
> index 95b608059d41..34d5ca566769 100644
> --- a/kexec/zlib.c
> +++ b/kexec/zlib.c
> @@ -23,6 +23,32 @@ static void _gzerror(gzFile fp, int *errnum, const char **errmsg)
>  	}
>  }
>  
> +int is_zlib_file(const char *filename, off_t *r_size)
> +{
> +	gzFile fp;
> +	int errnum;
> +	const char *msg;
> +
> +	if (!filename)
> +		goto out;
> +
> +	fp = gzopen(filename, "rb");

Does fp need to be closed somewhere to avoid a leak?

> +	if (fp == 0) {
> +		_gzerror(fp, &errnum, &msg);
> +		dbgprintf("Cannot open `%s': %s\n", filename, msg);
> +		goto out;
> +	}
> +
> +	if (gzdirect(fp))
> +		/* It's not in gzip format */
> +		goto out;
> +
> +	/* It's in gzip format */
> +	return 1;
> +out:
> +	return 0;
> +}
> +
>  char *zlib_decompress_file(const char *filename, off_t *r_size)
>  {
>  	gzFile fp;
> @@ -84,6 +110,12 @@ fail:
>  	return buf;
>  }
>  #else
> +
> +int is_zlib_file(const char *filename, off_t *r_size)
> +{
> +	return 0;
> +}
> +
>  char *zlib_decompress_file(const char *UNUSED(filename), off_t *UNUSED(r_size))
>  {
>  	return NULL;
> -- 
> 2.7.4
> 

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Re: [PATCH 4/4] kexec/arm64: Add support for handling zlib compressed (Image.gz) image

[Simon Horman]

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@redhat.com>
> ---
>  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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Re: [PATCH 4/4] kexec/arm64: Add support for handling zlib compressed (Image.gz) image

[Bhupesh Sharma]

Hi Simon,

Thanks for your review.

On Thu, Jul 11, 2019 at 3:38 PM Simon Horman <horms@verge.net.au> 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@redhat.com>
> > ---
> >  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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Re: [PATCH 3/4] kexec/kexec-zlib.h: Add 'is_zlib_file()' helper function

[Bhupesh Sharma]

Hi Simon,

On Thu, Jul 11, 2019 at 3:28 PM Simon Horman <horms@verge.net.au> wrote:
>
> On Thu, Jul 11, 2019 at 01:24:28AM +0530, Bhupesh Sharma wrote:
> > This patch adds 'is_zlib_file()' helper function which can be
> > used to quickly determine with the passed kernel image is a zlib
> > compressed kernel image.
> >
> > This is specifically useful for arm64 zImage (or Image.gz) support,
> > which is introduced by later patches in this patchset.
> >
> > Signed-off-by: Bhupesh Sharma <bhsharma@redhat.com>
> > ---
> >  kexec/kexec-zlib.h |  1 +
> >  kexec/zlib.c       | 32 ++++++++++++++++++++++++++++++++
> >  2 files changed, 33 insertions(+)
> >
> > diff --git a/kexec/kexec-zlib.h b/kexec/kexec-zlib.h
> > index 43c107bf4a72..16300f294759 100644
> > --- a/kexec/kexec-zlib.h
> > +++ b/kexec/kexec-zlib.h
> > @@ -6,5 +6,6 @@
> >
> >  #include "config.h"
> >
> > +int is_zlib_file(const char *filename, off_t *r_size);
> >  char *zlib_decompress_file(const char *filename, off_t *r_size);
> >  #endif /* __KEXEC_ZLIB_H */
> > diff --git a/kexec/zlib.c b/kexec/zlib.c
> > index 95b608059d41..34d5ca566769 100644
> > --- a/kexec/zlib.c
> > +++ b/kexec/zlib.c
> > @@ -23,6 +23,32 @@ static void _gzerror(gzFile fp, int *errnum, const char **errmsg)
> >       }
> >  }
> >
> > +int is_zlib_file(const char *filename, off_t *r_size)
> > +{
> > +     gzFile fp;
> > +     int errnum;
> > +     const char *msg;
> > +
> > +     if (!filename)
> > +             goto out;
> > +
> > +     fp = gzopen(filename, "rb");
>
> Does fp need to be closed somewhere to avoid a leak?

Right. Will fix this in v2.

v2 will be soon on its way.

Thanks,
Bhupesh

> > +     if (fp == 0) {
> > +             _gzerror(fp, &errnum, &msg);
> > +             dbgprintf("Cannot open `%s': %s\n", filename, msg);
> > +             goto out;
> > +     }
> > +
> > +     if (gzdirect(fp))
> > +             /* It's not in gzip format */
> > +             goto out;
> > +
> > +     /* It's in gzip format */
> > +     return 1;
> > +out:
> > +     return 0;
> > +}
> > +
> >  char *zlib_decompress_file(const char *filename, off_t *r_size)
> >  {
> >       gzFile fp;
> > @@ -84,6 +110,12 @@ fail:
> >       return buf;
> >  }
> >  #else
> > +
> > +int is_zlib_file(const char *filename, off_t *r_size)
> > +{
> > +     return 0;
> > +}
> > +
> >  char *zlib_decompress_file(const char *UNUSED(filename), off_t *UNUSED(r_size))
> >  {
> >       return NULL;
> > --
> > 2.7.4
> >

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