[PATCH] x86/power/64: Use char arrays for asm function names

[PATCH] x86/power/64: Use char arrays for asm function names

[Kees Cook]

This switches the hibernate_64.S function names into character arrays
to match other areas of the kernel where this is done (e.g., linker
scripts). Specifically this fixes a compile-time error noticed by the
future CONFIG_FORTIFY_SOURCE routines that complained about PAGE_SIZE
being copied out of the "single byte" core_restore_code variable.

Additionally drops the "acpi_save_state_mem" exern which does not
appear to be used anywhere else in the kernel.

Cc: Daniel Micay <danielmicay@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
---
 arch/x86/include/asm/suspend_64.h | 5 ++---
 arch/x86/power/hibernate_64.c     | 6 +++---
 2 files changed, 5 insertions(+), 6 deletions(-)

diff --git a/arch/x86/include/asm/suspend_64.h b/arch/x86/include/asm/suspend_64.h
index 6136a18152af..2bd96b4df140 100644
--- a/arch/x86/include/asm/suspend_64.h
+++ b/arch/x86/include/asm/suspend_64.h
@@ -42,8 +42,7 @@ struct saved_context {
 	set_debugreg((thread)->debugreg##register, register)
 
 /* routines for saving/restoring kernel state */
-extern int acpi_save_state_mem(void);
-extern char core_restore_code;
-extern char restore_registers;
+extern char core_restore_code[];
+extern char restore_registers[];
 
 #endif /* _ASM_X86_SUSPEND_64_H */
diff --git a/arch/x86/power/hibernate_64.c b/arch/x86/power/hibernate_64.c
index 6a61194ffd58..2cc419990ab7 100644
--- a/arch/x86/power/hibernate_64.c
+++ b/arch/x86/power/hibernate_64.c
@@ -147,7 +147,7 @@ static int relocate_restore_code(void)
 	if (!relocated_restore_code)
 		return -ENOMEM;
 
-	memcpy((void *)relocated_restore_code, &core_restore_code, PAGE_SIZE);
+	memcpy((void *)relocated_restore_code, core_restore_code, PAGE_SIZE);
 
 	/* Make the page containing the relocated code executable */
 	pgd = (pgd_t *)__va(read_cr3()) + pgd_index(relocated_restore_code);
@@ -292,8 +292,8 @@ int arch_hibernation_header_save(void *addr, unsigned int max_size)
 
 	if (max_size < sizeof(struct restore_data_record))
 		return -EOVERFLOW;
-	rdr->jump_address = (unsigned long)&restore_registers;
-	rdr->jump_address_phys = __pa_symbol(&restore_registers);
+	rdr->jump_address = (unsigned long)restore_registers;
+	rdr->jump_address_phys = __pa_symbol(restore_registers);
 	rdr->cr3 = restore_cr3;
 	rdr->magic = RESTORE_MAGIC;
 
-- 
2.7.4


-- 
Kees Cook
Pixel Security

Re: [PATCH] x86/power/64: Use char arrays for asm function names

[Rafael J. Wysocki]

On Tuesday, May 09, 2017 02:00:51 PM Kees Cook wrote:
> This switches the hibernate_64.S function names into character arrays
> to match other areas of the kernel where this is done (e.g., linker
> scripts). Specifically this fixes a compile-time error noticed by the
> future CONFIG_FORTIFY_SOURCE routines that complained about PAGE_SIZE
> being copied out of the "single byte" core_restore_code variable.
> 
> Additionally drops the "acpi_save_state_mem" exern which does not
> appear to be used anywhere else in the kernel.
> 
> Cc: Daniel Micay <danielmicay@gmail.com>
> Signed-off-by: Kees Cook <keescook@chromium.org>

Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Or I can queue this up if that's preferred.

> ---
>  arch/x86/include/asm/suspend_64.h | 5 ++---
>  arch/x86/power/hibernate_64.c     | 6 +++---
>  2 files changed, 5 insertions(+), 6 deletions(-)
> 
> diff --git a/arch/x86/include/asm/suspend_64.h b/arch/x86/include/asm/suspend_64.h
> index 6136a18152af..2bd96b4df140 100644
> --- a/arch/x86/include/asm/suspend_64.h
> +++ b/arch/x86/include/asm/suspend_64.h
> @@ -42,8 +42,7 @@ struct saved_context {
>  	set_debugreg((thread)->debugreg##register, register)
>  
>  /* routines for saving/restoring kernel state */
> -extern int acpi_save_state_mem(void);
> -extern char core_restore_code;
> -extern char restore_registers;
> +extern char core_restore_code[];
> +extern char restore_registers[];
>  
>  #endif /* _ASM_X86_SUSPEND_64_H */
> diff --git a/arch/x86/power/hibernate_64.c b/arch/x86/power/hibernate_64.c
> index 6a61194ffd58..2cc419990ab7 100644
> --- a/arch/x86/power/hibernate_64.c
> +++ b/arch/x86/power/hibernate_64.c
> @@ -147,7 +147,7 @@ static int relocate_restore_code(void)
>  	if (!relocated_restore_code)
>  		return -ENOMEM;
>  
> -	memcpy((void *)relocated_restore_code, &core_restore_code, PAGE_SIZE);
> +	memcpy((void *)relocated_restore_code, core_restore_code, PAGE_SIZE);
>  
>  	/* Make the page containing the relocated code executable */
>  	pgd = (pgd_t *)__va(read_cr3()) + pgd_index(relocated_restore_code);
> @@ -292,8 +292,8 @@ int arch_hibernation_header_save(void *addr, unsigned int max_size)
>  
>  	if (max_size < sizeof(struct restore_data_record))
>  		return -EOVERFLOW;
> -	rdr->jump_address = (unsigned long)&restore_registers;
> -	rdr->jump_address_phys = __pa_symbol(&restore_registers);
> +	rdr->jump_address = (unsigned long)restore_registers;
> +	rdr->jump_address_phys = __pa_symbol(restore_registers);
>  	rdr->cr3 = restore_cr3;
>  	rdr->magic = RESTORE_MAGIC;
>  
> 

Re: [PATCH] x86/power/64: Use char arrays for asm function names

[Ingo Molnar]

* Rafael J. Wysocki <rjw@rjwysocki.net> wrote:

> On Tuesday, May 09, 2017 02:00:51 PM Kees Cook wrote:
> > This switches the hibernate_64.S function names into character arrays
> > to match other areas of the kernel where this is done (e.g., linker
> > scripts). Specifically this fixes a compile-time error noticed by the
> > future CONFIG_FORTIFY_SOURCE routines that complained about PAGE_SIZE
> > being copied out of the "single byte" core_restore_code variable.
> > 
> > Additionally drops the "acpi_save_state_mem" exern which does not
> > appear to be used anywhere else in the kernel.
> > 
> > Cc: Daniel Micay <danielmicay@gmail.com>
> > Signed-off-by: Kees Cook <keescook@chromium.org>
> 
> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> 
> Or I can queue this up if that's preferred.

LGTM too!

Acked-by: Ingo Molnar <mingo@kernel.org>

Thanks,

	Ingo

Re: [PATCH] x86/power/64: Use char arrays for asm function names

[Pavel Machek]

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On Tue 2017-05-09 14:00:51, Kees Cook wrote:
> This switches the hibernate_64.S function names into character arrays
> to match other areas of the kernel where this is done (e.g., linker
> scripts). Specifically this fixes a compile-time error noticed by the
> future CONFIG_FORTIFY_SOURCE routines that complained about PAGE_SIZE
> being copied out of the "single byte" core_restore_code variable.

Can we get equivalent fix for suspend_32.h?

									Pavel

-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

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