• Brian King's avatar
    powerpc: Check for valid hugepage size in hugetlb_get_unmapped_area · 48f797de
    Brian King authored
    It looks like most of the hugetlb code is doing the correct thing if
    hugepages are not supported, but the mmap code is not.  If we get into
    the mmap code when hugepages are not supported, such as in an LPAR
    which is running Active Memory Sharing, we can oops the kernel.  This
    fixes the oops being seen in this path.
    
    oops: Kernel access of bad area, sig: 11 [#1]
    SMP NR_CPUS=1024 NUMA pSeries
    Modules linked in: nfs(N) lockd(N) nfs_acl(N) sunrpc(N) ipv6(N) fuse(N) loop(N)
    dm_mod(N) sg(N) ibmveth(N) sd_mod(N) crc_t10dif(N) ibmvscsic(N)
    scsi_transport_srp(N) scsi_tgt(N) scsi_mod(N)
    Supported: No
    NIP: c000000000038d60 LR: c00000000003945c CTR: c0000000000393f0
    REGS: c000000077e7b830 TRAP: 0300   Tainted: G
    (2.6.27.5-bz50170-2-ppc64)
    MSR: 8000000000009032 <EE,ME,IR,DR>  CR: 44000448  XER: 20000001
    DAR: c000002000af90a8, DSISR: 0000000040000000
    TASK = c00000007c1b8600[4019] 'hugemmap01' THREAD: c000000077e78000 CPU: 6
    GPR00: 0000001fffffffe0 c000000077e7bab0 c0000000009a4e78 0000000000000000
    GPR04: 0000000000010000 0000000000000001 00000000ffffffff 0000000000000001
    GPR08: 0000000000000000 c000000000af90c8 0000000000000001 0000000000000000
    GPR12: 000000000000003f c000000000a73880 0000000000000000 0000000000000000
    GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000010000
    GPR20: 0000000000000000 0000000000000003 0000000000010000 0000000000000001
    GPR24: 0000000000000003 0000000000000000 0000000000000001 ffffffffffffffb5
    GPR28: c000000077ca2e80 0000000000000000 c00000000092af78 0000000000010000
    NIP [c000000000038d60] .slice_get_unmapped_area+0x6c/0x4e0
    LR [c00000000003945c] .hugetlb_get_unmapped_area+0x6c/0x80
    Call Trace:
    [c000000077e7bbc0] [c00000000003945c] .hugetlb_get_unmapped_area+0x6c/0x80
    [c000000077e7bc30] [c000000000107e30] .get_unmapped_area+0x64/0xd8
    [c000000077e7bcb0] [c00000000010b140] .do_mmap_pgoff+0x140/0x420
    [c000000077e7bd80] [c00000000000bf5c] .sys_mmap+0xc4/0x140
    [c000000077e7be30] [c0000000000086b4] syscall_exit+0x0/0x40
    Instruction dump:
    fac1ffb0 fae1ffb8 fb01ffc0 fb21ffc8 fb41ffd0 fb61ffd8 fb81ffe0 fbc1fff0
    fbe1fff8 f821fef1 f8c10158 f8e10160 <7d49002e> f9010168 e92d01b0 eb4902b0
    Signed-off-by: default avatarBrian King <brking@linux.vnet.ibm.com>
    Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
    48f797de
hugetlbpage.c 20 KB