[J][PATCH 1/2] s390/kexec_file: move kernel image size check

[frank.heimes at canonical.com]

From: Sven Schnelle <svens at linux.ibm.com>

BugLink: https://bugs.launchpad.net/bugs/1959984

In preparation of adding support for command lines with variable
sizes on s390, the check whether the new kernel image is at least HEAD_END
bytes long isn't correct. Move the check to kexec_file_add_components()
so we can get the size of the parm area and check the size there.

The '.org HEAD_END' directive can now also be removed from head.S. This
was used in the past to reserve space for the early sccb buffer, but with
commit 9a5131b87cac1 ("s390/boot: move sclp early buffer from fixed address
in asm to C") this is no longer required.

Signed-off-by: Sven Schnelle <svens at linux.ibm.com>
Reviewed-by: Heiko Carstens <hca at linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor at linux.ibm.com>
(cherry picked from commit 277c8389386e2ccb8417afe4e36f67fc5dcd735d)
Signed-off-by: Frank Heimes <frank.heimes at canonical.com>
---
 arch/s390/boot/head.S                 |  2 --
 arch/s390/include/asm/setup.h         |  1 -
 arch/s390/kernel/machine_kexec_file.c | 25 ++-----------------------
 3 files changed, 2 insertions(+), 26 deletions(-)

diff --git a/arch/s390/boot/head.S b/arch/s390/boot/head.S
index 40f4cff538b8..f3a8dba7dd5d 100644
--- a/arch/s390/boot/head.S
+++ b/arch/s390/boot/head.S
@@ -383,5 +383,3 @@ SYM_DATA_START(parmarea)
 	.byte	0
 	.org	PARMAREA+__PARMAREA_SIZE
 SYM_DATA_END(parmarea)
-
-	.org	HEAD_END
diff --git a/arch/s390/include/asm/setup.h b/arch/s390/include/asm/setup.h
index b6606ffd85d8..121e1a8c41d7 100644
--- a/arch/s390/include/asm/setup.h
+++ b/arch/s390/include/asm/setup.h
@@ -11,7 +11,6 @@
 #include <linux/build_bug.h>
 
 #define PARMAREA		0x10400
-#define HEAD_END		0x11000
 
 /*
  * Machine features detected in early.c
diff --git a/arch/s390/kernel/machine_kexec_file.c b/arch/s390/kernel/machine_kexec_file.c
index a81d6c43b9b6..6944d9abee1e 100644
--- a/arch/s390/kernel/machine_kexec_file.c
+++ b/arch/s390/kernel/machine_kexec_file.c
@@ -235,7 +235,8 @@ void *kexec_file_add_components(struct kimage *image,
 	if (ret)
 		goto out;
 
-	if (image->cmdline_buf_len >= ARCH_COMMAND_LINE_SIZE) {
+	if (image->kernel_buf_len < PARMAREA + sizeof(struct parmarea) ||
+	    image->cmdline_buf_len >= ARCH_COMMAND_LINE_SIZE) {
 		ret = -EINVAL;
 		goto out;
 	}
@@ -324,25 +325,3 @@ int arch_kexec_apply_relocations_add(struct purgatory_info *pi,
 	}
 	return 0;
 }
-
-int arch_kexec_kernel_image_probe(struct kimage *image, void *buf,
-				  unsigned long buf_len)
-{
-	/* A kernel must be at least large enough to contain head.S. During
-	 * load memory in head.S will be accessed, e.g. to register the next
-	 * command line. If the next kernel were smaller the current kernel
-	 * will panic at load.
-	 */
-	if (buf_len < HEAD_END)
-		return -ENOEXEC;
-
-	return kexec_image_probe_default(image, buf, buf_len);
-}
-
-int arch_kimage_file_post_load_cleanup(struct kimage *image)
-{
-	vfree(image->arch.ipl_buf);
-	image->arch.ipl_buf = NULL;
-
-	return kexec_image_post_load_cleanup_default(image);
-}
-- 
2.25.1