powerpc/fsl-booke: Fix InstructionTLBError execute permission check

In CONFIG_PTE_64BIT the PTE format has unique permission bits for user and supervisor execute. However on !CONFIG_PTE_64BIT we overload the supervisor bit to imply user execute with _PAGE_USER set. This allows us to use the same permission check mask for user or supervisor code on !CONFIG_PTE_64BIT. However, on CONFIG_PTE_64BIT we map _PAGE_EXEC to _PAGE_BAP_UX so we need a different permission mask based on the fault coming from a kernel address or user space. Without unique permission masks we see issues like the following with modules: Unable to handle kernel paging request for instruction fetch Faulting instruction address: 0xf938d040 Oops: Kernel access of bad area, sig: 11 [#1] Signed-off-by: Li Yang <[email protected]> Signed-off-by: Jin Qing <[email protected]> Signed-off-by: Kumar Gala <[email protected]>
yshchan · May 17, 2010 · 78e2e68 · 78e2e68
1 parent 4c5ddd5
commit 78e2e68
Showing 1 changed file with 10 additions and 3 deletions.
diff --git a/arch/powerpc/kernel/head_fsl_booke.S b/arch/powerpc/kernel/head_fsl_booke.S
@@ -639,22 +639,29 @@ interrupt_base:
 	rlwinm	r12,r12,0,16,1
 	mtspr	SPRN_MAS1,r12
 
+	/* Make up the required permissions for kernel code */
+#ifdef CONFIG_PTE_64BIT
+	li	r13,_PAGE_PRESENT | _PAGE_BAP_SX
+	oris	r13,r13,_PAGE_ACCESSED@h
+#else
+	li	r13,_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_EXEC
+#endif
 	b	4f
 
 	/* Get the PGD for the current thread */
 3:
 	mfspr	r11,SPRN_SPRG_THREAD
 	lwz	r11,PGDIR(r11)
 
-4:
-	/* Make up the required permissions */
+	/* Make up the required permissions for user code */
 #ifdef CONFIG_PTE_64BIT
-	li	r13,_PAGE_PRESENT | _PAGE_EXEC
+	li	r13,_PAGE_PRESENT | _PAGE_BAP_UX
 	oris	r13,r13,_PAGE_ACCESSED@h
 #else
 	li	r13,_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_EXEC
 #endif
 
+4:
 	FIND_PTE
 	andc.	r13,r13,r11		/* Check permission */