This is a note to let you know that I've just added the patch titled sparc64: Don't bark so loudly about 32-bit tasks generating 64-bit fault addresses. to the 3.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: sparc64-don-t-bark-so-loudly-about-32-bit-tasks-generating-64-bit-fault-addresses.patch and it can be found in the queue-3.14 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From foo@baz Fri Aug 8 08:54:13 PDT 2014 From: "David S. Miller" <davem@xxxxxxxxxxxxx> Date: Tue, 6 May 2014 21:27:37 -0700 Subject: sparc64: Don't bark so loudly about 32-bit tasks generating 64-bit fault addresses. From: "David S. Miller" <davem@xxxxxxxxxxxxx> [ Upstream commit e5c460f46ae7ee94831cb55cb980f942aa9e5a85 ] This was found using Dave Jone's trinity tool. When a user process which is 32-bit performs a load or a store, the cpu chops off the top 32-bits of the effective address before translating it. This is because we run 32-bit tasks with the PSTATE_AM (address masking) bit set. We can't run the kernel with that bit set, so when the kernel accesses userspace no address masking occurs. Since a 32-bit process will have no mappings in that region we will properly fault, so we don't try to handle this using access_ok(), which can safely just be a NOP on sparc64. Real faults from 32-bit processes should never generate such addresses so a bug check was added long ago, and it barks in the logs if this happens. But it also barks when a kernel user access causes this condition, and that _can_ happen. For example, if a pointer passed into a system call is "0xfffffffc" and the kernel access 4 bytes offset from that pointer. Just handle such faults normally via the exception entries. Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- arch/sparc/mm/fault_64.c | 16 +--------------- 1 file changed, 1 insertion(+), 15 deletions(-) --- a/arch/sparc/mm/fault_64.c +++ b/arch/sparc/mm/fault_64.c @@ -281,18 +281,6 @@ static void noinline __kprobes bogus_32b show_regs(regs); } -static void noinline __kprobes bogus_32bit_fault_address(struct pt_regs *regs, - unsigned long addr) -{ - static int times; - - if (times++ < 10) - printk(KERN_ERR "FAULT[%s:%d]: 32-bit process " - "reports 64-bit fault address [%lx]\n", - current->comm, current->pid, addr); - show_regs(regs); -} - asmlinkage void __kprobes do_sparc64_fault(struct pt_regs *regs) { enum ctx_state prev_state = exception_enter(); @@ -322,10 +310,8 @@ asmlinkage void __kprobes do_sparc64_fau goto intr_or_no_mm; } } - if (unlikely((address >> 32) != 0)) { - bogus_32bit_fault_address(regs, address); + if (unlikely((address >> 32) != 0)) goto intr_or_no_mm; - } } if (regs->tstate & TSTATE_PRIV) { Patches currently in stable-queue which might be from davem@xxxxxxxxxxxxx are queue-3.14/sctp-fix-possible-seqlock-seadlock-in-sctp_packet_transmit.patch queue-3.14/sparc64-add-basic-validations-to-pud-pmd-_bad.patch queue-3.14/net-sendmsg-fix-null-pointer-dereference.patch queue-3.14/sparc64-ldc_connect-should-not-return-einval-when-handshake-is-in-progress.patch queue-3.14/sparc64-do-not-insert-non-valid-ptes-into-the-tsb-hash-table.patch queue-3.14/iovec-make-sure-the-caller-actually-wants-anything-in-memcpy_fromiovecend.patch queue-3.14/net-phy-re-apply-phy-fixups-during-phy_register_device.patch queue-3.14/sparc64-fix-hex-values-in-comment-above-pte_modify.patch queue-3.14/sparc64-don-t-bark-so-loudly-about-32-bit-tasks-generating-64-bit-fault-addresses.patch queue-3.14/sparc64-fix-argument-sign-extension-for-compat_sys_futex.patch queue-3.14/arch-sparc-math-emu-math_32.c-drop-stray-break-operator.patch queue-3.14/net-correctly-set-segment-mac_len-in-skb_segment.patch queue-3.14/sparc64-fix-executable-bit-testing-in-set_pmd_at-paths.patch queue-3.14/ip-make-ip-identifiers-less-predictable.patch queue-3.14/sparc64-fix-top-level-fault-handling-bugs.patch queue-3.14/sparc64-fix-huge-tsb-mapping-on-pre-ultrasparc-iii-cpus.patch queue-3.14/sparc64-give-more-detailed-information-in-pgd-pmd-_error-and-kill-pte_error.patch queue-3.14/bnx2x-fix-crash-during-tso-tunneling.patch queue-3.14/sparc64-don-t-use-_page_present-in-pte_modify-mask.patch queue-3.14/sparc64-make-itc_sync_lock-raw.patch queue-3.14/bbc-i2c-fix-bbc-i2c-envctrl-on-sunblade-2000.patch queue-3.14/sparc64-handle-32-bit-tasks-properly-in-compute_effective_address.patch queue-3.14/sunsab-fix-detection-of-break-on-sunsab-serial-console.patch queue-3.14/ip_tunnel-ipv4-fix-tunnels-with-local-any-remote-remote_ip.patch queue-3.14/net-sctp-inherit-auth_capable-on-init-collisions.patch queue-3.14/sparc64-fix-bugs-in-get_user_pages_fast-wrt.-thp.patch queue-3.14/sparc64-fix-huge-pmd-invalidation.patch queue-3.14/macvlan-initialize-vlan_features-to-turn-on-offload-support.patch queue-3.14/tcp-fix-integer-overflow-in-tcp-vegas.patch queue-3.14/inetpeer-get-rid-of-ip_id_count.patch queue-3.14/sparc64-use-ilog2_4mb-instead-of-constant-22.patch queue-3.14/bna-fix-performance-regression.patch queue-3.14/sparc64-add-membar-to-niagara2-memcpy-code.patch queue-3.14/sparc64-fix-range-check-in-kern_addr_valid.patch queue-3.14/sparc64-guard-against-flushing-openfirmware-mappings.patch queue-3.14/tcp-fix-integer-overflows-in-tcp-veno.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html