diff mbox series

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

Message ID 20220217083045.931758-2-frank.heimes@canonical.com
State New
Headers show
Series Long kernel command line on s390x (LP: 1960580) | expand

Commit Message

Frank Heimes Feb. 17, 2022, 8:30 a.m. UTC 
From: Sven Schnelle <svens@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@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
(cherry picked from commit 277c8389386e2ccb8417afe4e36f67fc5dcd735d)
Signed-off-by: Frank Heimes <frank.heimes@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(-)

Comments

Krzysztof Kozlowski Feb. 17, 2022, 8:47 a.m. UTC | #1 
On 17/02/2022 09:30, frank.heimes@canonical.com wrote:
> From: Sven Schnelle <svens@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@linux.ibm.com>
> Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
> (cherry picked from commit 277c8389386e2ccb8417afe4e36f67fc5dcd735d)
> Signed-off-by: Frank Heimes <frank.heimes@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)
> -{

This should stay. It was not part of original commit.

> -	vfree(image->arch.ipl_buf);
> -	image->arch.ipl_buf = NULL;
> -
> -	return kexec_image_post_load_cleanup_default(image);
> -}


Best regards,
Krzysztof
Tim Gardner Feb. 17, 2022, 1:05 p.m. UTC | #2 
On 2/17/22 1:47 AM, Krzysztof Kozlowski wrote:
> On 17/02/2022 09:30, frank.heimes@canonical.com wrote:
>> From: Sven Schnelle <svens@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@linux.ibm.com>
>> Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
>> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
>> (cherry picked from commit 277c8389386e2ccb8417afe4e36f67fc5dcd735d)

This is a backport.

>> Signed-off-by: Frank Heimes <frank.heimes@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)
>> -{
> 
> This should stay. It was not part of original commit.
> 
>> -	vfree(image->arch.ipl_buf);
>> -	image->arch.ipl_buf = NULL;
>> -
>> -	return kexec_image_post_load_cleanup_default(image);
>> -}
> 
> 
> Best regards,
> Krzysztof
>
Frank Heimes Feb. 17, 2022, 6:58 p.m. UTC | #3 
interesting...
a simple cherry-pick does indeed not work properly ...

I've created a backport, that only adds a bit more context, content-wise
it's the same

re-submit it soon as v2

(apologize)


On Thu, Feb 17, 2022 at 2:05 PM Tim Gardner <tim.gardner@canonical.com>
wrote:

>
>
> On 2/17/22 1:47 AM, Krzysztof Kozlowski wrote:
> > On 17/02/2022 09:30, frank.heimes@canonical.com wrote:
> >> From: Sven Schnelle <svens@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@linux.ibm.com>
> >> Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
> >> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
> >> (cherry picked from commit 277c8389386e2ccb8417afe4e36f67fc5dcd735d)
>
> This is a backport.
>
> >> Signed-off-by: Frank Heimes <frank.heimes@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)
> >> -{
> >
> > This should stay. It was not part of original commit.
> >
> >> -    vfree(image->arch.ipl_buf);
> >> -    image->arch.ipl_buf = NULL;
> >> -
> >> -    return kexec_image_post_load_cleanup_default(image);
> >> -}
> >
> >
> > Best regards,
> > Krzysztof
> >
>
> --
> -----------
> Tim Gardner
> Canonical, Inc
>
diff mbox series

Patch

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);
-}