Re: [REVIEW][PATCH 3/9] signal/powerpc: Call _exception_pkey directly from bad_key_fault_exception

[Stephen Rothwell]

Hi Eric,

On Tue, 18 Sep 2018 19:58:44 +0200 "Eric W. Biederman"  
wrote:
>
> This removes the need for other code paths to deal with pkey exceptions.
> 
> Signed-off-by: "Eric W. Biederman" 

Straight forward expansion.

Reviewed-by: Stephen Rothwell 

-- 
Cheers,
Stephen Rothwell


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[REVIEW][PATCH 3/9] signal/powerpc: Call _exception_pkey directly from bad_key_fault_exception

[Eric W. Biederman]

This removes the need for other code paths to deal with pkey exceptions.

Signed-off-by: "Eric W. Biederman" 
---
 arch/powerpc/mm/fault.c | 12 +++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c
index e5725fa96a48..5afc1ee55043 100644
--- a/arch/powerpc/mm/fault.c
+++ b/arch/powerpc/mm/fault.c
@@ -145,7 +145,17 @@ static noinline int bad_area(struct pt_regs *regs, 
unsigned long address)
 static int bad_key_fault_exception(struct pt_regs *regs, unsigned long address,
int pkey)
 {
-   return __bad_area_nosemaphore(regs, address, SEGV_PKUERR, pkey);
+   /*
+* If we are in kernel mode, bail out with a SEGV, this will
+* be caught by the assembly which will restore the non-volatile
+* registers before calling bad_page_fault()
+*/
+   if (!user_mode(regs))
+   return SIGSEGV;
+
+   _exception_pkey(SIGSEGV, regs, SEGV_PKUERR, address, pkey);
+
+   return 0;
 }
 
 static noinline int bad_access(struct pt_regs *regs, unsigned long address)
-- 
2.17.1