diff options
| author | Ken Chen <kenneth.w.chen@intel.com> | 2005-06-21 14:40:31 -0700 |
|---|---|---|
| committer | Tony Luck <tony.luck@intel.com> | 2005-06-21 14:40:31 -0700 |
| commit | 0393eed5c3220c9c3823a09a2d02329b8ff08b45 (patch) | |
| tree | c465ee4c3a0322a4e6533f4e1ec0968b8b254907 /arch/ia64 | |
| parent | 52a0de2cd2d3da8f90d88e2eccb63d0cadd6ae26 (diff) | |
[IA64] fix nested_dtlb_miss handler for hugetlb address
The nested_dtlb_miss handler currently does not handle fault from
hugetlb address correctly. It walks the page table assuming PAGE_SIZE.
Thus when taking a fault triggered from hugetlb address, it would not
calculate the pgd/pmd/pte address correctly and thus result an incorrect
invocation of ia64_do_page_fault(). In there, kernel will signal SIGBUS
and application dies (The faulting address is perfectly legal and we
have a valid pte for the corresponding user hugetlb address as well).
This patch fix the described kernel bug. Since nested_dtlb_miss is a
rare event and a slow path anyway, I'm making the change without #ifdef
CONFIG_HUGETLB_PAGE for code readability. Tony, please apply.
Signed-off-by: Ken Chen <kenneth.w.chen@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Diffstat (limited to 'arch/ia64')
| -rw-r--r-- | arch/ia64/kernel/ivt.S | 13 |
1 files changed, 9 insertions, 4 deletions
diff --git a/arch/ia64/kernel/ivt.S b/arch/ia64/kernel/ivt.S index d9c05d53435..2bc085a73e3 100644 --- a/arch/ia64/kernel/ivt.S +++ b/arch/ia64/kernel/ivt.S @@ -405,17 +405,22 @@ ENTRY(nested_dtlb_miss) * r30: continuation address * r31: saved pr * - * Clobbered: b0, r18, r19, r21, psr.dt (cleared) + * Clobbered: b0, r18, r19, r21, r22, psr.dt (cleared) */ rsm psr.dt // switch to using physical data addressing mov r19=IA64_KR(PT_BASE) // get the page table base address shl r21=r16,3 // shift bit 60 into sign bit + mov r18=cr.itir ;; shr.u r17=r16,61 // get the region number into r17 + extr.u r18=r18,2,6 // get the faulting page size ;; cmp.eq p6,p7=5,r17 // is faulting address in region 5? - shr.u r18=r16,PGDIR_SHIFT // get bits 33-63 of faulting address + add r22=-PAGE_SHIFT,r18 // adjustment for hugetlb address + add r18=PGDIR_SHIFT-PAGE_SHIFT,r18 ;; + shr.u r22=r16,r22 + shr.u r18=r16,r18 (p7) dep r17=r17,r19,(PAGE_SHIFT-3),3 // put region number bits in place srlz.d @@ -428,7 +433,7 @@ ENTRY(nested_dtlb_miss) (p6) dep r17=r18,r19,3,(PAGE_SHIFT-3) // r17=PTA + IFA(33,42)*8 (p7) dep r17=r18,r17,3,(PAGE_SHIFT-6) // r17=PTA + (((IFA(61,63) << 7) | IFA(33,39))*8) cmp.eq p7,p6=0,r21 // unused address bits all zeroes? - shr.u r18=r16,PMD_SHIFT // shift L2 index into position + shr.u r18=r22,PMD_SHIFT // shift L2 index into position ;; ld8 r17=[r17] // fetch the L1 entry (may be 0) ;; @@ -436,7 +441,7 @@ ENTRY(nested_dtlb_miss) dep r17=r18,r17,3,(PAGE_SHIFT-3) // compute address of L2 page table entry ;; (p7) ld8 r17=[r17] // fetch the L2 entry (may be 0) - shr.u r19=r16,PAGE_SHIFT // shift L3 index into position + shr.u r19=r22,PAGE_SHIFT // shift L3 index into position ;; (p7) cmp.eq.or.andcm p6,p7=r17,r0 // was L2 entry NULL? dep r17=r19,r17,3,(PAGE_SHIFT-3) // compute address of L3 page table entry |