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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 <leoli@freescale.com>
Signed-off-by: Jin Qing <b24347@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
This commit is contained in:
Li Yang 2010-05-07 16:38:34 +08:00 committed by Kumar Gala
parent 4c5ddd5269
commit 78e2e68a2b
1 changed files with 10 additions and 3 deletions
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13
arch/powerpc/kernel/head_fsl_booke.S
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@ -639,6 +639,13 @@ 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 */
@ -646,15 +653,15 @@ interrupt_base:
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 */