[PATCH 4/5] arm64: Scatter the logic of reading of kernel file into each probe

Pingfan Liu piliu at redhat.com
Thu May 4 19:54:36 PDT 2023


As more complicated capsule kernel format occurs like zboot, where the
compressed kernel is stored as a payload. The straight forward
decompression can not meet the demand.

So reading in the kernel file in a probe method and decide how to unfold
the content by the method itself.

Signed-off-by: Pingfan Liu <piliu 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/kexec-elf-arm64.c    |  7 ++++-
 kexec/arch/arm64/kexec-image-arm64.c  |  6 +++-
 kexec/arch/arm64/kexec-uImage-arm64.c | 17 ++++++++---
 kexec/arch/arm64/kexec-zImage-arm64.c | 13 ++++-----
 kexec/kexec.c                         | 42 ++++++++++++++++++---------
 kexec/kexec.h                         |  2 ++
 6 files changed, 60 insertions(+), 27 deletions(-)

diff --git a/kexec/arch/arm64/kexec-elf-arm64.c b/kexec/arch/arm64/kexec-elf-arm64.c
index 9238dd5..cedf3c6 100644
--- a/kexec/arch/arm64/kexec-elf-arm64.c
+++ b/kexec/arch/arm64/kexec-elf-arm64.c
@@ -16,11 +16,13 @@
 #include "kexec-elf.h"
 #include "kexec-syscall.h"
 
-int elf_arm64_probe(const char *kernel_buf, off_t kernel_size, struct kexec_info *info)
+int elf_arm64_probe(const char *kern_fname, off_t kernel_size, struct kexec_info *info)
 {
 	struct mem_ehdr ehdr;
+	char *kernel_buf;
 	int result;
 
+	kernel_buf = slurp_file(kern_fname, &kernel_size);
 	result = build_elf_exec_info(kernel_buf, kernel_size, &ehdr, 0);
 
 	if (result < 0) {
@@ -34,8 +36,11 @@ int elf_arm64_probe(const char *kernel_buf, off_t kernel_size, struct kexec_info
 		goto on_exit;
 	}
 
+	info->kernel_fd = open(kern_fname, O_RDONLY);
+	info->kernel_buf = kernel_buf;
 	result = 0;
 on_exit:
+	free(kernel_buf);
 	free_elf_info(&ehdr);
 	return result;
 }
diff --git a/kexec/arch/arm64/kexec-image-arm64.c b/kexec/arch/arm64/kexec-image-arm64.c
index 84aca72..90cd40a 100644
--- a/kexec/arch/arm64/kexec-image-arm64.c
+++ b/kexec/arch/arm64/kexec-image-arm64.c
@@ -14,10 +14,12 @@
 #include "kexec-syscall.h"
 #include "arch/options.h"
 
-int image_arm64_probe(const char *kernel_buf, off_t kernel_size, struct kexec_info *info)
+int image_arm64_probe(const char *kern_fname, off_t kernel_size, struct kexec_info *info)
 {
 	const struct arm64_image_header *h;
+	char *kernel_buf;
 
+	kernel_buf = slurp_file(kern_fname, &kernel_size);
 	if (kernel_size < sizeof(struct arm64_image_header)) {
 		dbgprintf("%s: No arm64 image header.\n", __func__);
 		return -1;
@@ -29,6 +31,8 @@ int image_arm64_probe(const char *kernel_buf, off_t kernel_size, struct kexec_in
 		dbgprintf("%s: Bad arm64 image header.\n", __func__);
 		return -1;
 	}
+	info->kernel_fd = open(kern_fname, O_RDONLY);
+	info->kernel_buf = kernel_buf;
 
 	return 0;
 }
diff --git a/kexec/arch/arm64/kexec-uImage-arm64.c b/kexec/arch/arm64/kexec-uImage-arm64.c
index f5b94c8..cce1c76 100644
--- a/kexec/arch/arm64/kexec-uImage-arm64.c
+++ b/kexec/arch/arm64/kexec-uImage-arm64.c
@@ -3,26 +3,35 @@
  */
 #include <stdint.h>
 #include <string.h>
+#include <stdlib.h>
+#include <fcntl.h>
 #include <sys/types.h>
 #include <image.h>
 #include <kexec-uImage.h>
 #include "../../kexec.h"
 #include "kexec-arm64.h"
 
-int uImage_arm64_probe(const char *buf, off_t len, struct kexec_info *info)
+int uImage_arm64_probe(const char *kern_fname, off_t len, struct kexec_info *info)
 {
 	int ret;
+	char *kernel_buf;
 
-	ret = uImage_probe_kernel(buf, len, IH_ARCH_ARM64);
+	kernel_buf = slurp_file(kern_fname, &len);
+	ret = uImage_probe_kernel(kernel_buf, len, IH_ARCH_ARM64);
 
 	/*  0 - valid uImage.
 	 * -1 - uImage is corrupted.
 	 *  1 - image is not a uImage.
 	 */
-	if (!ret)
+	if (!ret) {
+		info->kernel_fd = open(kern_fname, O_RDONLY);
+		info->kernel_buf = kernel_buf;
 		return 0;
-	else
+	}
+	else {
+		free(kernel_buf);
 		return -1;
+	}
 }
 
 int uImage_arm64_load(int argc, char **argv, const char *buf, off_t len,
diff --git a/kexec/arch/arm64/kexec-zImage-arm64.c b/kexec/arch/arm64/kexec-zImage-arm64.c
index 7877741..450a915 100644
--- a/kexec/arch/arm64/kexec-zImage-arm64.c
+++ b/kexec/arch/arm64/kexec-zImage-arm64.c
@@ -40,7 +40,7 @@
  * fd : File descriptor of the temp file containing the decompressed
  *      Image.
  */
-int zImage_arm64_probe(const char *kernel_buf, off_t kernel_size, struct kexec_info *info)
+int zImage_arm64_probe(const char *kernel, off_t kernel_size, struct kexec_info *info)
 {
 	int ret = -1;
 	int fd = 0;
@@ -49,7 +49,7 @@ int zImage_arm64_probe(const char *kernel_buf, off_t kernel_size, struct kexec_i
 	char *kernel_uncompressed_buf = NULL;
 	const struct arm64_image_header *h;
 
-	if (!is_zlib_file(kernel_buf, &kernel_size)) {
+	if (!is_zlib_file(kernel, &kernel_size)) {
 		dbgprintf("%s: Not an zImage file (Image.gz).\n", __func__);
 		return -1;
 	}
@@ -69,7 +69,7 @@ int zImage_arm64_probe(const char *kernel_buf, off_t kernel_size, struct kexec_i
 
 	/* slurp in the input kernel */
 	dbgprintf("%s: ", __func__);
-	kernel_uncompressed_buf = slurp_decompress_file(kernel_buf,
+	kernel_uncompressed_buf = slurp_decompress_file(kernel,
 							&kernel_size);
 
 	/* check for correct header magic */
@@ -108,13 +108,12 @@ int zImage_arm64_probe(const char *kernel_buf, off_t kernel_size, struct kexec_i
 		ret = -1;
 		goto fail_bad_header;
 	}
-
+	info->kernel_fd = kernel_fd;
+	info->kernel_buf = kernel_uncompressed_buf;
 	unlink(fname);
-
-	free(kernel_uncompressed_buf);
 	free(fname);
 
-	return kernel_fd;
+	return 0;
 
 fail_bad_header:
 	free(kernel_uncompressed_buf);
diff --git a/kexec/kexec.c b/kexec/kexec.c
index 116fb4a..dbd24aa 100644
--- a/kexec/kexec.c
+++ b/kexec/kexec.c
@@ -720,12 +720,13 @@ static int my_load(const char *type, int fileind, int argc, char **argv,
 		return -1;
 	}
 	kernel = argv[fileind];
+#ifndef __aarch64__
 	/* slurp in the input kernel */
 	kernel_buf = slurp_decompress_file(kernel, &kernel_size);
 
 	dbgprintf("kernel: %p kernel_size: %#llx\n",
 		  kernel_buf, (unsigned long long)kernel_size);
-
+#endif
 	if (get_memory_ranges(&info.memory_range, &info.memory_ranges,
 		info.kexec_flags) < 0 || info.memory_ranges == 0) {
 		fprintf(stderr, "Could not get memory layout\n");
@@ -742,13 +743,17 @@ static int my_load(const char *type, int fileind, int argc, char **argv,
 			return -1;
 		} else {
 			/* make sure our file is really of that type */
+
 #ifndef __aarch64__
 			if (file_type[i].probe(kernel_buf, kernel_size) < 0)
 				guess_only = 1;
 #else
-			if (file_type[i].probe(kernel_buf, kernel_size, &info) < 0)
+			if (file_type[i].probe(kernel_buf, kernel_size, &info) < 0) {
 				guess_only = 1;
-
+			} else {
+				if (info.kernel_buf != NULL)
+					kernel_buf = info.kernel_buf;
+			}
 #endif
 		}
 	}
@@ -758,8 +763,11 @@ static int my_load(const char *type, int fileind, int argc, char **argv,
 			if (file_type[i].probe(kernel_buf, kernel_size) == 0)
 				break;
 #else
-			if (file_type[i].probe(kernel_buf, kernel_size, &info) == 0)
+			if (file_type[i].probe(kernel, kernel_size, &info) >= 0) {
+				if (info.kernel_buf != NULL)
+					kernel_buf = info.kernel_buf;
 				break;
+			}
 #endif
 		}
 		if (i == file_types) {
@@ -1289,6 +1297,8 @@ static int do_kexec_file_load(int fileind, int argc, char **argv,
 
 	info.file_mode = 1;
 	info.initrd_fd = -1;
+	info.kernel_fd = -1;
+	info.kernel_buf = NULL;
 
 	if (!is_kexec_file_load_implemented())
 		return EFALLBACK;
@@ -1301,6 +1311,7 @@ static int do_kexec_file_load(int fileind, int argc, char **argv,
 
 	kernel = argv[fileind];
 
+#ifndef __aarch64__
 	kernel_fd = open(kernel, O_RDONLY);
 	if (kernel_fd == -1) {
 		fprintf(stderr, "Failed to open file %s:%s\n", kernel,
@@ -1310,21 +1321,24 @@ static int do_kexec_file_load(int fileind, int argc, char **argv,
 
 	/* slurp in the input kernel */
 	kernel_buf = slurp_decompress_file(kernel, &kernel_size);
+#endif
 
 	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, &info)) >= 0) {
-				kernel_fd = ret;
-				break;
-			}
-		} else
-			if (file_type[i].probe(kernel_buf, kernel_size, &info) >= 0)
+#ifndef __aarch64__
+		if (file_type[i].probe(kernel_buf, kernel_size) >= 0)
 				break;
 #else
-		if (file_type[i].probe(kernel_buf, kernel_size) >= 0)
+		if (file_type[i].probe(kernel, kernel_size, &info) >= 0) {
+			if (info.kernel_fd != -1) {
+				close(kernel_fd);
+				kernel_fd = info.kernel_fd;
+			}
+			if (info.kernel_buf != NULL) {
+				free(kernel_buf);
+				kernel_buf = info.kernel_buf;
+			}
 			break;
+		}
 #endif
 	}
 
diff --git a/kexec/kexec.h b/kexec/kexec.h
index 6e8430e..3349d16 100644
--- a/kexec/kexec.h
+++ b/kexec/kexec.h
@@ -164,7 +164,9 @@ struct kexec_info {
 	unsigned long file_mode :1;
 
 	/* Filled by kernel image processing code */
+	int kernel_fd;
 	int initrd_fd;
+	char *kernel_buf;
 	char *command_line;
 	int command_line_len;
 
-- 
2.31.1




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