commit af24ee9ea8 upstream.
Commit 493f3358cb added this call to
xfs_fs_geometry() in order to avoid passing kernel stack data back
to user space:
+ memset(geo, 0, sizeof(*geo));
Unfortunately, one of the callers of that function passes the
address of a smaller data type, cast to fit the type that
xfs_fs_geometry() requires. As a result, this can happen:
Kernel panic - not syncing: stack-protector: Kernel stack is corrupted
in: f87aca93
Pid: 262, comm: xfs_fsr Not tainted 2.6.38-rc6-493f3358cb2+ #1
Call Trace:
[<c12991ac>] ? panic+0x50/0x150
[<c102ed71>] ? __stack_chk_fail+0x10/0x18
[<f87aca93>] ? xfs_ioc_fsgeometry_v1+0x56/0x5d [xfs]
Fix this by fixing that one caller to pass the right type and then
copy out the subset it is interested in.
Note: This patch is an alternative to one originally proposed by
Eric Sandeen.
Reported-by: Jeffrey Hundstad <jeffrey.hundstad@mnsu.edu>
Signed-off-by: Alex Elder <aelder@sgi.com>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Tested-by: Jeffrey Hundstad <jeffrey.hundstad@mnsu.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
commit 1b1f693d7a upstream.
As reported by Thomas Pollet, the rdma page counting can overflow. We
get the rdma sizes in 64-bit unsigned entities, but then limit it to
UINT_MAX bytes and shift them down to pages (so with a possible "+1" for
an unaligned address).
So each individual page count fits comfortably in an 'unsigned int' (not
even close to overflowing into signed), but as they are added up, they
might end up resulting in a signed return value. Which would be wrong.
Catch the case of tot_pages turning negative, and return the appropriate
error code.
Reported-by: Thomas Pollet <thomas.pollet@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Andy Grover <andy.grover@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
commit 114279be21 upstream.
Note: this patch targets 2.6.37 and tries to be as simple as possible.
That is why it adds more copy-and-paste horror into fs/compat.c and
uglifies fs/exec.c, this will be cleanuped later.
compat_copy_strings() plays with bprm->vma/mm directly and thus has
two problems: it lacks the RLIMIT_STACK check and argv/envp memory
is not visible to oom killer.
Export acct_arg_size() and get_arg_page(), change compat_copy_strings()
to use get_arg_page(), change compat_do_execve() to do acct_arg_size(0)
as do_execve() does.
Add the fatal_signal_pending/cond_resched checks into compat_count() and
compat_copy_strings(), this matches the code in fs/exec.c and certainly
makes sense.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Cc: Moritz Muehlenhoff <jmm@debian.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
commit 3c77f84572 upstream.
Brad Spengler published a local memory-allocation DoS that
evades the OOM-killer (though not the virtual memory RLIMIT):
http://www.grsecurity.net/~spender/64bit_dos.c
execve()->copy_strings() can allocate a lot of memory, but
this is not visible to oom-killer, nobody can see the nascent
bprm->mm and take it into account.
With this patch get_arg_page() increments current's MM_ANONPAGES
counter every time we allocate the new page for argv/envp. When
do_execve() succeds or fails, we change this counter back.
Technically this is not 100% correct, we can't know if the new
page is swapped out and turn MM_ANONPAGES into MM_SWAPENTS, but
I don't think this really matters and everything becomes correct
once exec changes ->mm or fails.
Reported-by: Brad Spengler <spender@grsecurity.net>
Reviewed-and-discussed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Moritz Muehlenhoff <jmm@debian.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
commit 9f260e0efa upstream.
Since the socket address is just being used as a unique identifier, its
inode number is an alternative that does not leak potentially sensitive
information.
CC-ing stable because MITRE has assigned CVE-2010-4565 to the issue.
Signed-off-by: Dan Rosenberg <drosenberg@vsecurity.com>
Acked-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Cc: Moritz Muehlenhoff <jmm@debian.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
commit fdac1e0697 upstream.
If the user-provided len is less than the expected offset, the
IRLMP_ENUMDEVICES getsockopt will do a copy_to_user() with a very large
size value. While this isn't be a security issue on x86 because it will
get caught by the access_ok() check, it may leak large amounts of kernel
heap on other architectures. In any event, this patch fixes it.
Signed-off-by: Dan Rosenberg <drosenberg@vsecurity.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Cc: Moritz Muehlenhoff <jmm@debian.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
commit 4e085e76cb upstream.
Unconditional use of skb->dev won't work here,
try to fetch the econet device via skb_dst()->dev
instead.
Suggested by Eric Dumazet.
Reported-by: Nelson Elhage <nelhage@ksplice.com>
Tested-by: Nelson Elhage <nelhage@ksplice.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Cc: Moritz Muehlenhoff <jmm@debian.org>
[jmm: Slightly adapted for 2.6.32]
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
commit 22e76c849d upstream.
We were using nlmsg_find_attr() to look up the bytecode by attribute when
auditing, but then just using the first attribute when actually running
bytecode. So, if we received a message with two attribute elements, where only
the second had type INET_DIAG_REQ_BYTECODE, we would validate and run different
bytecode strings.
Fix this by consistently using nlmsg_find_attr everywhere.
Signed-off-by: Nelson Elhage <nelhage@ksplice.com>
Signed-off-by: Thomas Graf <tgraf@infradead.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
[jmm: Slightly adapted to apply against 2.6.32]
Cc: Moritz Muehlenhoff <jmm@debian.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
commit 88f8a5e3e7 upstream.
Structure sockaddr_tipc is copied to userland with padding bytes after
"id" field in union field "name" unitialized. It leads to leaking of
contents of kernel stack memory. We have to initialize them to zero.
Signed-off-by: Vasiliy Kulikov <segooon@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Cc: Moritz Muehlenhoff <jmm@debian.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
commit 954032d252 upstream.
This was noticed by users who performed more than 2^32 lock operations
and hence made this counter overflow (eventually leading to
use-after-free's). Setting rq_client to NULL here means that it won't
later get auth_domain_put() when it should be.
Appears to have been introduced in 2.5.42 by "[PATCH] kNFSd: Move auth
domain lookup into svcauth" which moved most of the rq_client handling
to common svcauth code, but left behind this one line.
Cc: Neil Brown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
commit 5b41395fcc upstream.
When writing a contiguous set of blocks, two indirect blocks could be
needed depending on how the blocks are aligned, so we need to increase
the number of credits needed by one.
[ Also fixed a another bug which could further underestimate the
number of journal credits needed by 1; the code was using integer
division instead of DIV_ROUND_UP() -- tytso]
Signed-off-by: Yongqiang Yang <xiaoqiangnk@gmail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
commit 67286640f6 upstream.
packet_getname_spkt() doesn't initialize all members of sa_data field of
sockaddr struct if strlen(dev->name) < 13. This structure is then copied
to userland. It leads to leaking of contents of kernel stack memory.
We have to fully fill sa_data with strncpy() instead of strlcpy().
The same with packet_getname(): it doesn't initialize sll_pkttype field of
sockaddr_ll. Set it to zero.
Signed-off-by: Vasiliy Kulikov <segooon@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Cc: Moritz Muehlenhoff <jmm@debian.org>
[jmm: Backported to 2.6.32]
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
commit fe10ae5338 upstream.
Sometimes ax25_getname() doesn't initialize all members of fsa_digipeater
field of fsa struct, also the struct has padding bytes between
sax25_call and sax25_ndigis fields. This structure is then copied to
userland. It leads to leaking of contents of kernel stack memory.
Signed-off-by: Vasiliy Kulikov <segooon@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Cc: Moritz Muehlenhoff <jmm@debian.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
commit 18b429e74e upstream.
Omit pkt_hdr preamble when dumping transmitted packet as hex-dump;
we can pull this up because the frame has already been sent, and
dumping it is the last thing we do with it before freeing it.
Also include the size, vpi, and vci in the debug as is done on
receive.
Use "port" consistently instead of "device" intermittently.
Signed-off-by: Philip Prindeville <philipp@redfish-solutions.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
commit 44cff8a9ee upstream.
Handle the rare case where a directory metadata block is uncompressed and
corrupted, leading to a kernel oops in directory scanning (memcpy).
Normally corruption is detected at the decompression stage and dealt with
then, however, this will not happen if:
- metadata isn't compressed (users can optionally request no metadata
compression), or
- the compressed metadata block was larger than the original, in which
case the uncompressed version was used, or
- the data was corrupt after decompression
This patch fixes this by adding some sanity checks against known maximum
values.
Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
powerpc: Fix default_machine_crash_shutdown #ifdef botch
Commit: c2be05481f upstream
crash_kexec_wait_realmode() is defined only if CONFIG_PPC_STD_MMU_64
and CONFIG_SMP, but is called if CONFIG_PPC_STD_MMU_64 even if !CONFIG_SMP.
Fix the conditional compilation around the invocation.
Reported-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
cc: Anton Blanchard <anton@samba.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Upstream commit: 44d60c0f5c
The different families have a different max size for the ucode patch,
adjust size checking to the family we're running on. Also, do not
vzalloc the max size of the ucode but only the actual size that is
passed on from the firmware loader.
Cc: <stable@kernel.org>
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
commit 6d152e23ad upstream.
Like Herbert's change from a few days ago:
66c46d741e gro: Reset dev pointer on reuse
this may not be necessary at this point, but we should still clean up
the skb->skb_iif. If not we may end up with an invalid valid for
skb->skb_iif when the skb is reused and the check is done in
__netif_receive_skb.
Signed-off-by: Andy Gospodarek <andy@greyhouse.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Brandon Philips <bphilips@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
commit 66c46d741e upstream.
On older kernels the VLAN code may zero skb->dev before dropping
it and causing it to be reused by GRO.
Unfortunately we didn't reset skb->dev in that case which causes
the next GRO user to get a bogus skb->dev pointer.
This particular problem no longer happens with the current upstream
kernel due to changes in VLAN processing.
However, for correctness we should still reset the skb->dev pointer
in the GRO reuse function in case a future user does the same thing.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Brandon Philips <bphilips@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
commit fb82c0ff27 upstream.
The gdbserial protocol handler should return an empty packet instead
of an error string when ever it responds to a command it does not
implement.
The problem cases come from a debugger client sending
qTBuffer, qTStatus, qSearch, qSupported.
The incorrect response from the gdbstub leads the debugger clients to
not function correctly. Recent versions of gdb will not detach correctly as a result of this behavior.
Backport-request-by: Frank Pan <frankpzh@gmail.com>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Dongdong Deng <dongdong.deng@windriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
commit b769f49463 upstream.
Was: [PATCH] sound/oss/midi_synth: prevent underflow, use of
uninitialized value, and signedness issue
The offset passed to midi_synth_load_patch() can be essentially
arbitrary. If it's greater than the header length, this will result in
a copy_from_user(dst, src, negative_val). While this will just return
-EFAULT on x86, on other architectures this may cause memory corruption.
Additionally, the length field of the sysex_info structure may not be
initialized prior to its use. Finally, a signed comparison may result
in an unintentionally large loop.
On suggestion by Takashi Iwai, version two removes the offset argument
from the load_patch callbacks entirely, which also resolves similar
issues in opl3. Compile tested only.
v3 adjusts comments and hopefully gets copy offsets right.
Signed-off-by: Dan Rosenberg <drosenberg@vsecurity.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
commit 67c5c6cb81 upstream.
struct aunhdr has 4 padding bytes between 'pad' and 'handle' fields on
x86_64. These bytes are not initialized in the variable 'ah' before
sending 'ah' to the network. This leads to 4 bytes kernel stack
infoleak.
This bug was introduced before the git epoch.
Signed-off-by: Vasiliy Kulikov <segoon@openwall.com>
Acked-by: Phil Blundell <philb@gnu.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
commit 6a8ab06077 upstream.
Structures ip6t_replace, compat_ip6t_replace, and xt_get_revision are
copied from userspace. Fields of these structs that are
zero-terminated strings are not checked. When they are used as argument
to a format string containing "%s" in request_module(), some sensitive
information is leaked to userspace via argument of spawned modprobe
process.
The first bug was introduced before the git epoch; the second was
introduced in 3bc3fe5e (v2.6.25-rc1); the third is introduced by
6b7d31fc (v2.6.15-rc1). To trigger the bug one should have
CAP_NET_ADMIN.
Signed-off-by: Vasiliy Kulikov <segoon@openwall.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
commit 961ed183a9 upstream.
'buffer' string is copied from userspace. It is not checked whether it is
zero terminated. This may lead to overflow inside of simple_strtoul().
Changli Gao suggested to copy not more than user supplied 'size' bytes.
It was introduced before the git epoch. Files "ipt_CLUSTERIP/*" are
root writable only by default, however, on some setups permissions might be
relaxed to e.g. network admin user.
Signed-off-by: Vasiliy Kulikov <segoon@openwall.com>
Acked-by: Changli Gao <xiaosuo@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
commit 42eab94fff upstream.
Structures ipt_replace, compat_ipt_replace, and xt_get_revision are
copied from userspace. Fields of these structs that are
zero-terminated strings are not checked. When they are used as argument
to a format string containing "%s" in request_module(), some sensitive
information is leaked to userspace via argument of spawned modprobe
process.
The first bug was introduced before the git epoch; the second is
introduced by 6b7d31fc (v2.6.15-rc1); the third is introduced by
6b7d31fc (v2.6.15-rc1). To trigger the bug one should have
CAP_NET_ADMIN.
Signed-off-by: Vasiliy Kulikov <segoon@openwall.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
commit 78b7987676 upstream.
Structures ipt_replace, compat_ipt_replace, and xt_get_revision are
copied from userspace. Fields of these structs that are
zero-terminated strings are not checked. When they are used as argument
to a format string containing "%s" in request_module(), some sensitive
information is leaked to userspace via argument of spawned modprobe
process.
The first and the third bugs were introduced before the git epoch; the
second was introduced in 2722971c (v2.6.17-rc1). To trigger the bug
one should have CAP_NET_ADMIN.
Signed-off-by: Vasiliy Kulikov <segoon@openwall.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
commit 1309d7afbe upstream.
This patch fixes information leakage to the userspace by initializing
the data buffer to zero.
Reported-by: Peter Huewe <huewe.external@infineon.com>
Signed-off-by: Peter Huewe <huewe.external@infineon.com>
Signed-off-by: Marcel Selhorst <m.selhorst@sirrix.com>
[ Also removed the silly "* sizeof(u8)". If that isn't 1, we have way
deeper problems than a simple multiplication can fix. - Linus ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
commit 272b62c1f0 upstream.
When a hole spans across page boundaries, the next write forces
a read of the block. This could end up reading existing garbage
data from the disk in ocfs2_map_page_blocks. This leads to
non-zero holes. In order to avoid this, mark the writes as new
when the holes span across page boundaries.
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.de>
Signed-off-by: jlbec <jlbec@evilplan.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
commit 43629f8f5e upstream.
Struct ca is copied from userspace. It is not checked whether the "device"
field is NULL terminated. This potentially leads to BUG() inside of
alloc_netdev_mqs() and/or information leak by creating a device with a name
made of contents of kernel stack.
Signed-off-by: Vasiliy Kulikov <segoon@openwall.com>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
commit d846f71195 upstream.
Struct tmp is copied from userspace. It is not checked whether the "name"
field is NULL terminated. This may lead to buffer overflow and passing
contents of kernel stack as a module name to try_then_request_module() and,
consequently, to modprobe commandline. It would be seen by all userspace
processes.
Signed-off-by: Vasiliy Kulikov <segoon@openwall.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
commit c4c896e147 upstream.
struct sco_conninfo has one padding byte in the end. Local variable
cinfo of type sco_conninfo is copied to userspace with this uninizialized
one byte, leading to old stack contents leak.
Signed-off-by: Vasiliy Kulikov <segoon@openwall.com>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
commit 982134ba62 upstream.
The normal mmap paths all avoid creating a mapping where the pgoff
inside the mapping could wrap around due to overflow. However, an
expanding mremap() can take such a non-wrapping mapping and make it
bigger and cause a wrapping condition.
Noticed by Robert Swiecki when running a system call fuzzer, where it
caused a BUG_ON() due to terminally confusing the vma_prio_tree code. A
vma dumping patch by Hugh then pinpointed the crazy wrapped case.
Reported-and-tested-by: Robert Swiecki <robert@swiecki.net>
Acked-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
commit b03f24567c upstream.
There's no reason to write quota info in dquot_commit(). The writing is a
relict from the old days when we didn't have dquot_acquire() and
dquot_release() and thus dquot_commit() could have created / removed quota
structures from the file. These days dquot_commit() only updates usage counters
/ limits in quota structure and thus there's no need to write quota info.
This also fixes an issue with journaling filesystem which didn't reserve
enough space in the transaction for write of quota info (it could have been
dirty at the time of dquot_commit() because of a race with other operation
changing it).
Reported-and-tested-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
commit 7da6443aca upstream.
This patch fixes a debugging failure with which looks like this:
UBIFS error (pid 32313): dbg_check_space_info: free space changed from 6019344 to 6022654
The reason for this failure is described in the comment this patch adds
to the code. But in short - 'c->freeable_cnt' may be different before
and after re-mounting, and this is normal. So the debugging code should
make sure that free space calculations do not depend on 'c->freeable_cnt'.
A similar issue has been reported here:
http://lists.infradead.org/pipermail/linux-mtd/2011-April/034647.html
This patch should fix it.
For the -stable guys: this patch is only relevant for kernels 2.6.30
onwards.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
commit 54acbaaa52 upstream.
Thanks to coverity which spotted that UBIFS will oops if 'kmalloc()'
in 'read_pnode()' fails and we dereference a NULL 'pnode' pointer
when we 'goto out'.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
commit 8b229c7676 upstream.
This fix makes the 'dbg_check_old_index()' function return
immediately if debugging is disabled, instead of executing
incorrect 'goto out' which causes UBIFS to:
1. Allocate memory
2. Read the flash
On every commit. OK, we do not commit that often, but it is
still silly to do unneeded I/O anyway.
Credits to coverity for spotting this silly issue.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
commit f62d816fc4 upstream.
When the chip is still asleep when ath9k_start is called,
ath9k_hw_configpcipowersave can trigger a data bus error.
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
commit 84ac7cdbdd upstream.
On laptops with core i5/i7, there were reports that after resume
graphics workloads were performing poorly on a specific AP, while
the other cpu's were ok. This was observed on a 32bit kernel
specifically.
Debug showed that the PAT init was not happening on that AP
during resume and hence it contributing to the poor workload
performance on that cpu.
On this system, resume flow looked like this:
1. BP starts the resume sequence and we reinit BP's MTRR's/PAT
early on using mtrr_bp_restore()
2. Resume sequence brings all AP's online
3. Resume sequence now kicks off the MTRR reinit on all the AP's.
4. For some reason, between point 2 and 3, we moved from BP
to one of the AP's. My guess is that printk() during resume
sequence is contributing to this. We don't see similar
behavior with the 64bit kernel but there is no guarantee that
at this point the remaining resume sequence (after AP's bringup)
has to happen on BP.
5. set_mtrr() was assuming that we are still on BP and skipped the
MTRR/PAT init on that cpu (because of 1 above)
6. But we were on an AP and this led to not reprogramming PAT
on this cpu leading to bad performance.
Fix this by doing unconditional mtrr_if->set_all() in set_mtrr()
during MTRR/PAT init. This might be unnecessary if we are still
running on BP. But it is of no harm and will guarantee that after
resume, all the cpu's will be in sync with respect to the
MTRR/PAT registers.
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
LKML-Reference: <1301438292-28370-1-git-send-email-eric@anholt.net>
Signed-off-by: Eric Anholt <eric@anholt.net>
Tested-by: Keith Packard <keithp@keithp.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
