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Subject: Re: [PATCHv3 0/2] Stackleak for arm64
To:     Will Deacon <will.deacon@arm.com>
Cc:     Alexander Popov <alex.popov@linux.com>,
        Kees Cook <keescook@chromium.org>,
        Mark Rutland <mark.rutland@arm.com>,
        Ard Biesheuvel <ard.biesheuvel@linaro.org>,
        kernel-hardening@lists.openwall.com,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
        Catalin Marinas <catalin.marinas@arm.com>, james.morse@arm.com
References: <1531341400-12077-1-git-send-email-alex.popov@linux.com>
 <20180720214154.2940-1-labbott@redhat.com> <20180724163807.GE25888@arm.com>
 <20180725114954.GD30289@arm.com>
From:   Laura Abbott <labbott@redhat.com>
Message-ID: <fbf890f6-7424-362e-95dd-223262e5f19e@redhat.com>
Date:   Wed, 25 Jul 2018 15:05:58 -0700
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On 07/25/2018 04:49 AM, Will Deacon wrote:
> Hi Laura,
> 
> On Tue, Jul 24, 2018 at 05:38:07PM +0100, Will Deacon wrote:
>> On Fri, Jul 20, 2018 at 02:41:52PM -0700, Laura Abbott wrote:
>>> This is the version of stackleak for arm64, hopefully ready for queueing
>>
>> Thanks. I'll push these into linux-next tomorrow, once I've had a chance
>> to test my conflict resolution in entry.S.
> 
> I've run into a couple of issues with this series:
> 
> 1. I had to install libmpc-dev to get GCC_PLUGINS to appear, otherwise the
>     hostcc check would silently fail. I guess that's a general observation,
>     but it might be nice to print a message about the missing dependencies.
> 
> 2. It breaks arm64 allmodconfig build. Log below.
> 
> Please can you take a look at the build failure? Otherwise, the patches
> look good to me.
> 
> Cheers,
> 
> Will
> 
> --->8
> 
> arch/arm64/kernel/sdei.c: In function ‘on_sdei_normal_stack’:
> arch/arm64/kernel/sdei.c:101:7: error: dereferencing pointer to incomplete type ‘struct stack_info’
>     info->low = low;
>         ^~
> arch/arm64/kernel/sdei.c:103:16: error: ‘STACK_TYPE_SDEI_NORMAL’ undeclared (first use in this function); did you mean ‘SCHED_NORMAL’?
>     info->type = STACK_TYPE_SDEI_NORMAL;
>                  ^~~~~~~~~~~~~~~~~~~~~~
>                  SCHED_NORMAL
> arch/arm64/kernel/sdei.c:103:16: note: each undeclared identifier is reported only once for each function it appears in
> arch/arm64/kernel/sdei.c: In function ‘on_sdei_critical_stack’:
> arch/arm64/kernel/sdei.c:121:16: error: ‘STACK_TYPE_SDEI_CRITICAL’ undeclared (first use in this function)
>     info->type = STACK_TYPE_SDEI_CRITICAL;
>                  ^~~~~~~~~~~~~~~~~~~~~~~~
> arch/arm64/kernel/sdei.c: At top level:
> arch/arm64/kernel/sdei.c:127:6: error: conflicting types for ‘_on_sdei_stack’
>   bool _on_sdei_stack(unsigned long sp,
>        ^~~~~~~~~~~~~~
> In file included from ./include/linux/arm_sdei.h:14:0,
>                   from arch/arm64/kernel/sdei.c:5:
> ./arch/arm64/include/asm/sdei.h:45:6: note: previous declaration of ‘_on_sdei_stack’ was here
>   bool _on_sdei_stack(unsigned long sp, struct stack_info *info);
>        ^~~~~~~~~~~~~~
> arch/arm64/kernel/sdei.c: In function ‘_on_sdei_stack’:
> arch/arm64/kernel/sdei.c:136:33: error: ‘info’ undeclared (first use in this function); did you mean ‘int’?
>    if (on_sdei_critical_stack(sp, info))
>                                   ^~~~
>                                   int
> arch/arm64/kernel/sdei.c:131:21: warning: unused variable ‘high’ [-Wunused-variable]
>    unsigned long low, high;
>                       ^~~~
> arch/arm64/kernel/sdei.c:131:16: warning: unused variable ‘low’ [-Wunused-variable]
>    unsigned long low, high;
>                  ^~~
> make[1]: *** [arch/arm64/kernel/sdei.o] Error 1
> make[1]: *** Waiting for unfinished jobs....
> make: *** [arch/arm64/kernel] Error 2
> 

Ugh this was a failure that I missed folding in, sorry about that

--- 8< ----

diff --git a/arch/arm64/kernel/sdei.c b/arch/arm64/kernel/sdei.c
index 7154fee1cb2b..a94a868f0532 100644
--- a/arch/arm64/kernel/sdei.c
+++ b/arch/arm64/kernel/sdei.c
@@ -13,6 +13,7 @@
  #include <asm/mmu.h>
  #include <asm/ptrace.h>
  #include <asm/sections.h>
+#include <asm/stacktrace.h>
  #include <asm/sysreg.h>
  #include <asm/vmap_stack.h>
  
@@ -125,11 +126,8 @@ bool on_sdei_critical_stack(unsigned long sp,
  }
  
  bool _on_sdei_stack(unsigned long sp,
-		unsigned long *stack_low,
-		unsigned long *stack_high)
+		struct stack_info *info)
  {
-	unsigned long low, high;
-
  	if (!IS_ENABLED(CONFIG_VMAP_STACK))
  		return false;