diff mbox

[V4] ZBOOT: fix stack protector in compressed boot phase

Message ID 1522226296-3091-1-git-send-email-chenhc@lemote.com (mailing list archive)
State New, archived
Headers show

Commit Message

Huacai Chen March 28, 2018, 8:38 a.m. UTC 
Call __stack_chk_guard_setup() in decompress_kernel() is too late that
stack checking always fails for decompress_kernel() itself. So remove
__stack_chk_guard_setup() and initialize __stack_chk_guard before we
call decompress_kernel().

Original code comes from ARM but also used for MIPS and SH, so fix them
together. If without this fix, compressed booting of these archs will
fail because stack checking is enabled by default (>=4.16).

V1 -> V2: Fix build on ARM.
V2 -> V3: Fix build on SuperH.
V3 -> V4: Initialize __stack_chk_guard in C code as a constant.

Cc: stable@vger.kernel.org
Signed-off-by: Huacai Chen <chenhc@lemote.com>
---
 arch/arm/boot/compressed/head.S        | 4 ++++
 arch/arm/boot/compressed/misc.c        | 7 -------
 arch/mips/boot/compressed/decompress.c | 7 -------
 arch/mips/boot/compressed/head.S       | 4 ++++
 arch/sh/boot/compressed/head_32.S      | 8 ++++++++
 arch/sh/boot/compressed/head_64.S      | 4 ++++
 arch/sh/boot/compressed/misc.c         | 7 -------
 7 files changed, 20 insertions(+), 21 deletions(-)

Comments

Baruch Siach March 28, 2018, 8:41 a.m. UTC | #1 
Hi Huacai,

On Wed, Mar 28, 2018 at 04:38:16PM +0800, Huacai Chen wrote:
> Call __stack_chk_guard_setup() in decompress_kernel() is too late that
> stack checking always fails for decompress_kernel() itself. So remove
> __stack_chk_guard_setup() and initialize __stack_chk_guard before we
> call decompress_kernel().
> 
> Original code comes from ARM but also used for MIPS and SH, so fix them
> together. If without this fix, compressed booting of these archs will
> fail because stack checking is enabled by default (>=4.16).
> 
> V1 -> V2: Fix build on ARM.
> V2 -> V3: Fix build on SuperH.
> V3 -> V4: Initialize __stack_chk_guard in C code as a constant.
> 
> Cc: stable@vger.kernel.org
> Signed-off-by: Huacai Chen <chenhc@lemote.com>
> ---
>  arch/arm/boot/compressed/head.S        | 4 ++++
>  arch/arm/boot/compressed/misc.c        | 7 -------
>  arch/mips/boot/compressed/decompress.c | 7 -------
>  arch/mips/boot/compressed/head.S       | 4 ++++
>  arch/sh/boot/compressed/head_32.S      | 8 ++++++++
>  arch/sh/boot/compressed/head_64.S      | 4 ++++
>  arch/sh/boot/compressed/misc.c         | 7 -------
>  7 files changed, 20 insertions(+), 21 deletions(-)

This diffstat doesn't match the patch below. The patch touches no .S file.

baruch

> 
> diff --git a/arch/arm/boot/compressed/misc.c b/arch/arm/boot/compressed/misc.c
> index 16a8a80..e8fe51f 100644
> --- a/arch/arm/boot/compressed/misc.c
> +++ b/arch/arm/boot/compressed/misc.c
> @@ -128,12 +128,7 @@ asmlinkage void __div0(void)
>  	error("Attempting division by 0!");
>  }
>  
> -unsigned long __stack_chk_guard;
> -
> -void __stack_chk_guard_setup(void)
> -{
> -	__stack_chk_guard = 0x000a0dff;
> -}
> +const unsigned long __stack_chk_guard = 0x000a0dff;
>  
>  void __stack_chk_fail(void)
>  {
> @@ -150,8 +145,6 @@ decompress_kernel(unsigned long output_start, unsigned long free_mem_ptr_p,
>  {
>  	int ret;
>  
> -	__stack_chk_guard_setup();
> -
>  	output_data		= (unsigned char *)output_start;
>  	free_mem_ptr		= free_mem_ptr_p;
>  	free_mem_end_ptr	= free_mem_ptr_end_p;
> diff --git a/arch/mips/boot/compressed/decompress.c b/arch/mips/boot/compressed/decompress.c
> index fdf99e9..81df904 100644
> --- a/arch/mips/boot/compressed/decompress.c
> +++ b/arch/mips/boot/compressed/decompress.c
> @@ -76,12 +76,7 @@ void error(char *x)
>  #include "../../../../lib/decompress_unxz.c"
>  #endif
>  
> -unsigned long __stack_chk_guard;
> -
> -void __stack_chk_guard_setup(void)
> -{
> -	__stack_chk_guard = 0x000a0dff;
> -}
> +const unsigned long __stack_chk_guard = 0x000a0dff;
>  
>  void __stack_chk_fail(void)
>  {
> @@ -92,8 +87,6 @@ void decompress_kernel(unsigned long boot_heap_start)
>  {
>  	unsigned long zimage_start, zimage_size;
>  
> -	__stack_chk_guard_setup();
> -
>  	zimage_start = (unsigned long)(&__image_begin);
>  	zimage_size = (unsigned long)(&__image_end) -
>  	    (unsigned long)(&__image_begin);
> diff --git a/arch/sh/boot/compressed/misc.c b/arch/sh/boot/compressed/misc.c
> index 627ce8e..c15cac9 100644
> --- a/arch/sh/boot/compressed/misc.c
> +++ b/arch/sh/boot/compressed/misc.c
> @@ -104,12 +104,7 @@ static void error(char *x)
>  	while(1);	/* Halt */
>  }
>  
> -unsigned long __stack_chk_guard;
> -
> -void __stack_chk_guard_setup(void)
> -{
> -	__stack_chk_guard = 0x000a0dff;
> -}
> +const unsigned long __stack_chk_guard = 0x000a0dff;
>  
>  void __stack_chk_fail(void)
>  {
> @@ -130,8 +125,6 @@ void decompress_kernel(void)
>  {
>  	unsigned long output_addr;
>  
> -	__stack_chk_guard_setup();
> -
>  #ifdef CONFIG_SUPERH64
>  	output_addr = (CONFIG_MEMORY_START + 0x2000);
>  #else
diff mbox

Patch

diff --git a/arch/arm/boot/compressed/misc.c b/arch/arm/boot/compressed/misc.c
index 16a8a80..e8fe51f 100644
--- a/arch/arm/boot/compressed/misc.c
+++ b/arch/arm/boot/compressed/misc.c
@@ -128,12 +128,7 @@  asmlinkage void __div0(void)
 	error("Attempting division by 0!");
 }
 
-unsigned long __stack_chk_guard;
-
-void __stack_chk_guard_setup(void)
-{
-	__stack_chk_guard = 0x000a0dff;
-}
+const unsigned long __stack_chk_guard = 0x000a0dff;
 
 void __stack_chk_fail(void)
 {
@@ -150,8 +145,6 @@  decompress_kernel(unsigned long output_start, unsigned long free_mem_ptr_p,
 {
 	int ret;
 
-	__stack_chk_guard_setup();
-
 	output_data		= (unsigned char *)output_start;
 	free_mem_ptr		= free_mem_ptr_p;
 	free_mem_end_ptr	= free_mem_ptr_end_p;
diff --git a/arch/mips/boot/compressed/decompress.c b/arch/mips/boot/compressed/decompress.c
index fdf99e9..81df904 100644
--- a/arch/mips/boot/compressed/decompress.c
+++ b/arch/mips/boot/compressed/decompress.c
@@ -76,12 +76,7 @@  void error(char *x)
 #include "../../../../lib/decompress_unxz.c"
 #endif
 
-unsigned long __stack_chk_guard;
-
-void __stack_chk_guard_setup(void)
-{
-	__stack_chk_guard = 0x000a0dff;
-}
+const unsigned long __stack_chk_guard = 0x000a0dff;
 
 void __stack_chk_fail(void)
 {
@@ -92,8 +87,6 @@  void decompress_kernel(unsigned long boot_heap_start)
 {
 	unsigned long zimage_start, zimage_size;
 
-	__stack_chk_guard_setup();
-
 	zimage_start = (unsigned long)(&__image_begin);
 	zimage_size = (unsigned long)(&__image_end) -
 	    (unsigned long)(&__image_begin);
diff --git a/arch/sh/boot/compressed/misc.c b/arch/sh/boot/compressed/misc.c
index 627ce8e..c15cac9 100644
--- a/arch/sh/boot/compressed/misc.c
+++ b/arch/sh/boot/compressed/misc.c
@@ -104,12 +104,7 @@  static void error(char *x)
 	while(1);	/* Halt */
 }
 
-unsigned long __stack_chk_guard;
-
-void __stack_chk_guard_setup(void)
-{
-	__stack_chk_guard = 0x000a0dff;
-}
+const unsigned long __stack_chk_guard = 0x000a0dff;
 
 void __stack_chk_fail(void)
 {
@@ -130,8 +125,6 @@  void decompress_kernel(void)
 {
 	unsigned long output_addr;
 
-	__stack_chk_guard_setup();
-
 #ifdef CONFIG_SUPERH64
 	output_addr = (CONFIG_MEMORY_START + 0x2000);
 #else