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 3.4-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-3.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.
>From foo@baz Thu Aug 7 22:33:35 PDT 2014
From: "David S. Miller" <[email protected]>
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" <[email protected]>
[ 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 <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
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
@@ -282,18 +282,6 @@ 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)
{
struct mm_struct *mm = current->mm;
@@ -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 [email protected] are
queue-3.4/sparc64-add-membar-to-niagara2-memcpy-code.patch
queue-3.4/ip-make-ip-identifiers-less-predictable.patch
queue-3.4/sunsab-fix-detection-of-break-on-sunsab-serial-console.patch
queue-3.4/tcp-fix-integer-overflow-in-tcp-vegas.patch
queue-3.4/tcp-fix-integer-overflows-in-tcp-veno.patch
queue-3.4/sparc64-fix-huge-tsb-mapping-on-pre-ultrasparc-iii-cpus.patch
queue-3.4/sparc64-handle-32-bit-tasks-properly-in-compute_effective_address.patch
queue-3.4/macvlan-initialize-vlan_features-to-turn-on-offload-support.patch
queue-3.4/inetpeer-get-rid-of-ip_id_count.patch
queue-3.4/arch-sparc-math-emu-math_32.c-drop-stray-break-operator.patch
queue-3.4/sparc64-do-not-insert-non-valid-ptes-into-the-tsb-hash-table.patch
queue-3.4/sparc64-fix-argument-sign-extension-for-compat_sys_futex.patch
queue-3.4/bbc-i2c-fix-bbc-i2c-envctrl-on-sunblade-2000.patch
queue-3.4/sparc64-guard-against-flushing-openfirmware-mappings.patch
queue-3.4/sparc64-ldc_connect-should-not-return-einval-when-handshake-is-in-progress.patch
queue-3.4/sparc64-fix-top-level-fault-handling-bugs.patch
queue-3.4/sparc64-don-t-bark-so-loudly-about-32-bit-tasks-generating-64-bit-fault-addresses.patch
queue-3.4/net-sendmsg-fix-null-pointer-dereference.patch
queue-3.4/net-sctp-inherit-auth_capable-on-init-collisions.patch
queue-3.4/sparc64-make-itc_sync_lock-raw.patch
queue-3.4/sctp-fix-possible-seqlock-seadlock-in-sctp_packet_transmit.patch
queue-3.4/iovec-make-sure-the-caller-actually-wants-anything-in-memcpy_fromiovecend.patch
queue-3.4/net-correctly-set-segment-mac_len-in-skb_segment.patch
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