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  1. 04 9月, 2009 1 次提交
    • P
      kmemleak: Don't scan uninitialized memory when kmemcheck is enabled · 8e019366
      由 Pekka Enberg 提交于 
      Ingo Molnar reported the following kmemcheck warning when running both
kmemleak and kmemcheck enabled:

  PM: Adding info for No Bus:vcsa7
  WARNING: kmemcheck: Caught 32-bit read from uninitialized memory
  (f6f6e1a4)
  d873f9f600000000c42ae4c1005c87f70000000070665f666978656400000000
   i i i i u u u u i i i i i i i i i i i i i i i i i i i i i u u u
           ^

  Pid: 3091, comm: kmemleak Not tainted (2.6.31-rc7-tip #1303) P4DC6
  EIP: 0060:[<c110301f>] EFLAGS: 00010006 CPU: 0
  EIP is at scan_block+0x3f/0xe0
  EAX: f40bd700 EBX: f40bd780 ECX: f16b46c0 EDX: 00000001
  ESI: f6f6e1a4 EDI: 00000000 EBP: f10f3f4c ESP: c2605fcc
   DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068
  CR0: 8005003b CR2: e89a4844 CR3: 30ff1000 CR4: 000006f0
  DR0: 00000000 DR1: 00000000 DR2: 00000000 DR3: 00000000
  DR6: ffff4ff0 DR7: 00000400
   [<c110313c>] scan_object+0x7c/0xf0
   [<c1103389>] kmemleak_scan+0x1d9/0x400
   [<c1103a3c>] kmemleak_scan_thread+0x4c/0xb0
   [<c10819d4>] kthread+0x74/0x80
   [<c10257db>] kernel_thread_helper+0x7/0x3c
   [<ffffffff>] 0xffffffff
  kmemleak: 515 new suspected memory leaks (see
  /sys/kernel/debug/kmemleak)
  kmemleak: 42 new suspected memory leaks (see /sys/kernel/debug/kmemleak)

The problem here is that kmemleak will scan partially initialized
objects that makes kmemcheck complain. Fix that up by skipping
uninitialized memory regions when kmemcheck is enabled.
Reported-by: NIngo Molnar <mingo@elte.hu>
Acked-by: NIngo Molnar <mingo@elte.hu>
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>
      8e019366
  3. 03 9月, 2009 35 次提交
  5. 02 9月, 2009 1 次提交
    • D
      KEYS: Add a keyctl to install a process's session keyring on its parent [try #6] · ee18d64c
      由 David Howells 提交于 
      Add a keyctl to install a process's session keyring onto its parent.  This
replaces the parent's session keyring.  Because the COW credential code does
not permit one process to change another process's credentials directly, the
change is deferred until userspace next starts executing again.  Normally this
will be after a wait*() syscall.

To support this, three new security hooks have been provided:
cred_alloc_blank() to allocate unset security creds, cred_transfer() to fill in
the blank security creds and key_session_to_parent() - which asks the LSM if
the process may replace its parent's session keyring.

The replacement may only happen if the process has the same ownership details
as its parent, and the process has LINK permission on the session keyring, and
the session keyring is owned by the process, and the LSM permits it.

Note that this requires alteration to each architecture's notify_resume path.
This has been done for all arches barring blackfin, m68k* and xtensa, all of
which need assembly alteration to support TIF_NOTIFY_RESUME.  This allows the
replacement to be performed at the point the parent process resumes userspace
execution.

This allows the userspace AFS pioctl emulation to fully emulate newpag() and
the VIOCSETTOK and VIOCSETTOK2 pioctls, all of which require the ability to
alter the parent process's PAG membership.  However, since kAFS doesn't use
PAGs per se, but rather dumps the keys into the session keyring, the session
keyring of the parent must be replaced if, for example, VIOCSETTOK is passed
the newpag flag.

This can be tested with the following program:

	#include <stdio.h>
	#include <stdlib.h>
	#include <keyutils.h>

	#define KEYCTL_SESSION_TO_PARENT	18

	#define OSERROR(X, S) do { if ((long)(X) == -1) { perror(S); exit(1); } } while(0)

	int main(int argc, char **argv)
	{
		key_serial_t keyring, key;
		long ret;

		keyring = keyctl_join_session_keyring(argv[1]);
		OSERROR(keyring, "keyctl_join_session_keyring");

		key = add_key("user", "a", "b", 1, keyring);
		OSERROR(key, "add_key");

		ret = keyctl(KEYCTL_SESSION_TO_PARENT);
		OSERROR(ret, "KEYCTL_SESSION_TO_PARENT");

		return 0;
	}

Compiled and linked with -lkeyutils, you should see something like:

	[dhowells@andromeda ~]$ keyctl show
	Session Keyring
	       -3 --alswrv   4043  4043  keyring: _ses
	355907932 --alswrv   4043    -1   \_ keyring: _uid.4043
	[dhowells@andromeda ~]$ /tmp/newpag
	[dhowells@andromeda ~]$ keyctl show
	Session Keyring
	       -3 --alswrv   4043  4043  keyring: _ses
	1055658746 --alswrv   4043  4043   \_ user: a
	[dhowells@andromeda ~]$ /tmp/newpag hello
	[dhowells@andromeda ~]$ keyctl show
	Session Keyring
	       -3 --alswrv   4043  4043  keyring: hello
	340417692 --alswrv   4043  4043   \_ user: a

Where the test program creates a new session keyring, sticks a user key named
'a' into it and then installs it on its parent.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NJames Morris <jmorris@namei.org>
      ee18d64c
  7. 01 9月, 2009 1 次提交
  9. 26 8月, 2009 2 次提交
    • Y
      x86: Fix vSMP boot crash · 295594e9
      由 Yinghai Lu 提交于 
      2.6.31-rc7 does not boot on vSMP systems:

[    8.501108] CPU31: Thermal monitoring enabled (TM1)
[    8.501127] CPU 31 MCA banks SHD:2 SHD:3 SHD:5 SHD:6 SHD:8
[    8.650254] CPU31: Intel(R) Xeon(R) CPU           E5540  @ 2.53GHz stepping 04
[    8.710324] Brought up 32 CPUs
[    8.713916] Total of 32 processors activated (162314.96 BogoMIPS).
[    8.721489] ERROR: parent span is not a superset of domain->span
[    8.727686] ERROR: domain->groups does not contain CPU0
[    8.733091] ERROR: groups don't span domain->span
[    8.737975] ERROR: domain->cpu_power not set
[    8.742416]

Ravikiran Thirumalai bisected it to:

| commit 2759c328
| x86: don't call read_apic_id if !cpu_has_apic

The problem is that on vSMP systems the CPUID derived
initial-APICIDs are overlapping - so we need to fall
back on hard_smp_processor_id() which reads the local
APIC.

Both come from the hardware (influenced by firmware
though) so it's a tough call which one to trust.

Doing the quirk expresses the vSMP property properly
and also does not affect other systems, so we go for
this solution instead of a revert.
Reported-and-Tested-by: NRavikiran Thirumalai <kiran@scalex86.org>
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Cyrill Gorcunov <gorcunov@gmail.com>
Cc: Shai Fultheim <shai@scalex86.org>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
LKML-Reference: <4A944D3C.5030100@kernel.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
      295594e9
    • H
      x86, xen: Initialize cx to suppress warning · 7adb4df4
      由 H. Peter Anvin 提交于 
      Initialize cx before calling xen_cpuid(), in order to suppress the
"may be used uninitialized in this function" warning.
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
      7adb4df4