Patchwork sparc: Fix user_addr_max() definition.

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Submitter David Miller
Date May 24, 2012, 8:57 p.m.
Message ID <20120524.165728.2124546768664666818.davem@davemloft.net>
Download mbox | patch
Permalink /patch/161203/
State Accepted
Delegated to: David Miller
Headers show

Comments

David Miller - May 24, 2012, 8:57 p.m.
We need to use TASK_SIZE because for 64-bit tasks the value
of STACK_TOP actually sits in the middle of the address space
so we'll get false-negatives.

Adjust the TASK_SIZE definition on sparc64 to accomodate this,
in the context in which user_addr_max() is used we have the
test_thread_flag() definition available but not the one for
test_tsk_thread_flag().

Signed-off-by: David S. Miller <davem@davemloft.net>
---

Some glibc testsuite failures for 64-bit showed me that
STACK_TOP isn't the right thing to use here because of
how we place the 64-bit process stack in the middle
of the address space.

Committed to master.

 arch/sparc/include/asm/processor_64.h |    4 +++-
 arch/sparc/include/asm/uaccess.h      |    2 +-
 2 files changed, 4 insertions(+), 2 deletions(-)

Patch

diff --git a/arch/sparc/include/asm/processor_64.h b/arch/sparc/include/asm/processor_64.h
index e713db2..6ca7709 100644
--- a/arch/sparc/include/asm/processor_64.h
+++ b/arch/sparc/include/asm/processor_64.h
@@ -42,7 +42,9 @@ 
 #define TASK_SIZE_OF(tsk) \
 	(test_tsk_thread_flag(tsk,TIF_32BIT) ? \
 	 (1UL << 32UL) : ((unsigned long)-VPTE_SIZE))
-#define TASK_SIZE	TASK_SIZE_OF(current)
+#define TASK_SIZE \
+	(test_thread_flag(TIF_32BIT) ? \
+	 (1UL << 32UL) : ((unsigned long)-VPTE_SIZE))
 #ifdef __KERNEL__
 
 #define STACK_TOP32	((1UL << 32UL) - PAGE_SIZE)
diff --git a/arch/sparc/include/asm/uaccess.h b/arch/sparc/include/asm/uaccess.h
index 20c2acb..0167d26 100644
--- a/arch/sparc/include/asm/uaccess.h
+++ b/arch/sparc/include/asm/uaccess.h
@@ -7,7 +7,7 @@ 
 #endif
 
 #define user_addr_max() \
-	(segment_eq(get_fs(), USER_DS) ? STACK_TOP : ~0UL)
+	(segment_eq(get_fs(), USER_DS) ? TASK_SIZE : ~0UL)
 
 extern long strncpy_from_user(char *dest, const char __user *src, long count);