| Date | Thu, 01 Jul 2010 10:42:51 -0700 | From | Greg KH <> | Subject | [081/200] powerpc/fsl-booke: Fix InstructionTLBError execute permission check |
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2.6.34-stable review patch. If anyone has any objections, please let me know.
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From: Li Yang <leoli@freescale.com>
commit 78e2e68a2b79f394b7cd61e07987a8a89af907f7 upstream.
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> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
--- arch/powerpc/kernel/head_fsl_booke.S | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-)
--- a/arch/powerpc/kernel/head_fsl_booke.S +++ b/arch/powerpc/kernel/head_fsl_booke.S @@ -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 */
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