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  1. 20 Nov, 2009 1 commit
    • Thomas Gleixner's avatar
      x86: Prevent GCC 4.4.x (pentium-mmx et al) function prologue wreckage · 746357d6
      Thomas Gleixner authored 
      When the kernel is compiled with -pg for tracing GCC 4.4.x inserts
stack alignment of a function _before_ the mcount prologue if the
-march=pentium-mmx is set and -mtune=generic is not set. This breaks
the assumption of the function graph tracer which expects that the
mcount prologue

       push %ebp
       mov  %esp, %ebp

is the first stack operation in a function because it needs to modify
the function return address on the stack to trap into the tracer
before returning to the real caller.

The generated code is:

        push   %edi
        lea    0x8(%esp),%edi
        and    $0xfffffff0,%esp
        pushl  -0x4(%edi)
        push   %ebp
        mov    %esp,%ebp

so the tracer modifies the copy of the return address which is stored
after the stack alignment and therefor does not trap the return which
in turn breaks the call chain logic of the tracer and leads to a
kernel panic.

Aside of the fact that the generated code is horrible for no good
reason other -march -mtune options generate the expected:

        push   %ebp
        mov    %esp,%ebp
        and    $0xfffffff0,%esp

which does the same and keeps everything intact.

After some experimenting we found out that this problem is restricted
to gcc4.4.x and to the following -march settings:

i586, pentium, pentium-mmx, k6, k6-2, k6-3, winchip-c6, winchip2, c3,
geode

By adding -mtune=generic the code generator produces always the
expected code.

So forcing -mtune=generic when CONFIG_FUNCTION_GRAPH_TRACER=y is not
pretty, but at the moment the only way to prevent that the kernel
trips over gcc-shrooms induced code madness.

Most distro kernels have CONFIG_X86_GENERIC=y anyway which forces
-mtune=generic as well so it will not impact those.

References: http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42109
	    http://lkml.org/lkml/2009/11/19/17Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
LKML-Reference: <alpine.LFD.2.00.0911200206570.24119@localhost.localdomain>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>,
Cc: Jeff Law <law@redhat.com>
Cc: gcc@gcc.gnu.org
Cc: David Daney <ddaney@caviumnetworks.com>
Cc: Andrew Haley <aph@redhat.com>
Cc: Richard Guenther <richard.guenther@gmail.com>
Cc: stable@kernel.org
      746357d6
  3. 16 Nov, 2009 1 commit
    • Prarit Bhargava's avatar
      x86: AMD Northbridge: Verify NB's node is online · 303fc087
      Prarit Bhargava authored 
      Fix panic seen on some IBM and HP systems on 2.6.32-rc6:

 BUG: unable to handle kernel NULL pointer dereference at (null)
 IP: [<ffffffff8120bf3f>] find_next_bit+0x77/0x9c
  [...]
  [<ffffffff8120bbde>] cpumask_next_and+0x2e/0x3b
  [<ffffffff81225c62>] pci_device_probe+0x8e/0xf5
  [<ffffffff812b9be6>] ? driver_sysfs_add+0x47/0x6c
  [<ffffffff812b9da5>] driver_probe_device+0xd9/0x1f9
  [<ffffffff812b9f1d>] __driver_attach+0x58/0x7c
  [<ffffffff812b9ec5>] ? __driver_attach+0x0/0x7c
  [<ffffffff812b9298>] bus_for_each_dev+0x54/0x89
  [<ffffffff812b9b4f>] driver_attach+0x19/0x1b
  [<ffffffff812b97ae>] bus_add_driver+0xd3/0x23d
  [<ffffffff812ba1e7>] driver_register+0x98/0x109
  [<ffffffff81225ed0>] __pci_register_driver+0x63/0xd3
  [<ffffffff81072776>] ? up_read+0x26/0x2a
  [<ffffffffa0081000>] ? k8temp_init+0x0/0x20 [k8temp]
  [<ffffffffa008101e>] k8temp_init+0x1e/0x20 [k8temp]
  [<ffffffff8100a073>] do_one_initcall+0x6d/0x185
  [<ffffffff8108d765>] sys_init_module+0xd3/0x236
  [<ffffffff81011ac2>] system_call_fastpath+0x16/0x1b

I put in a printk and commented out the set_dev_node()
call when and got this output:

 quirk_amd_nb_node: current numa_node = 0x0, would set to val & 7 = 0x0
 quirk_amd_nb_node: current numa_node = 0x0, would set to val & 7 = 0x1
 quirk_amd_nb_node: current numa_node = 0x0, would set to val & 7 = 0x2
 quirk_amd_nb_node: current numa_node = 0x0, would set to val & 7 = 0x3

I.e. the issue appears to be that the HW has set val to a valid
value, however, the system is only configured for a single
node -- 0, the others are offline.

Check to see if the node is actually online before setting
the numa node for an AMD northbridge in quirk_amd_nb_node().
Signed-off-by: default avatarPrarit Bhargava <prarit@redhat.com>
Cc: bhavna.sarathy@amd.com
Cc: jbarnes@virtuousgeek.org
Cc: andreas.herrmann3@amd.com
LKML-Reference: <20091112180933.12532.98685.sendpatchset@prarit.bos.redhat.com>
[ v2: clean up the code and add comments ]
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      303fc087
  5. 11 Nov, 2009 1 commit
  7. 10 Nov, 2009 3 commits
  9. 08 Nov, 2009 1 commit
  11. 06 Nov, 2009 1 commit
  13. 04 Nov, 2009 1 commit
    • Stefani Seibold's avatar
      x86, fs: Fix x86 procfs stack information for threads on 64-bit · 89240ba0
      Stefani Seibold authored 
      This patch fixes two issues in the procfs stack information on
x86-64 linux.

The 32 bit loader compat_do_execve did not store stack
start. (this was figured out by Alexey Dobriyan).

The stack information on a x64_64 kernel always shows 0 kbyte
stack usage, because of a missing implementation of the KSTK_ESP
macro which always returned -1.

The new implementation now returns the right value.
Signed-off-by: default avatarStefani Seibold <stefani@seibold.net>
Cc: Americo Wang <xiyou.wangcong@gmail.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
LKML-Reference: <1257240160.4889.24.camel@wall-e>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      89240ba0
  15. 03 Nov, 2009 2 commits
  17. 02 Nov, 2009 2 commits
  19. 29 Oct, 2009 1 commit
  21. 28 Oct, 2009 1 commit
  23. 27 Oct, 2009 1 commit
  25. 26 Oct, 2009 3 commits
    • Jan Beulich's avatar
      x86-64: Fix register leak in 32-bit syscall audting · 81766741
      Jan Beulich authored 
      Restoring %ebp after the call to audit_syscall_exit() is not
only unnecessary (because the register didn't get clobbered),
but in the sysenter case wasn't even doing the right thing: It
loaded %ebp from a location below the top of stack (RBP <
ARGOFFSET), i.e. arbitrary kernel data got passed back to user
mode in the register.
Signed-off-by: default avatarJan Beulich <jbeulich@novell.com>
Acked-by: default avatarRoland McGrath <roland@redhat.com>
Cc: <stable@kernel.org>
LKML-Reference: <4AE5CC4D020000780001BD13@vpn.id2.novell.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      81766741
    • Jiri Slaby's avatar
      x86: crash_dump: Fix non-pae kdump kernel memory accesses · 72ed7de7
      Jiri Slaby authored 
      Non-PAE 32-bit dump kernels may wrap an address around 4G and
poke unwanted space. ptes there are 32-bit long, and since
pfn << PAGE_SIZE may exceed this limit, high pfn bits are
cropped and wrong address mapped by kmap_atomic_pfn in
copy_oldmem_page.

Don't allow this behavior in non-PAE kdump kernels by checking
pfns passed into copy_oldmem_page. In the case of failure,
userspace process gets EFAULT.

[v2]
- fix comments
- move ifdefs inside the function
Signed-off-by: default avatarJiri Slaby <jirislaby@gmail.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Simon Horman <horms@verge.net.au>
Cc: Paul Mundt <lethal@linux-sh.org>
LKML-Reference: <1256551903-30567-1-git-send-email-jirislaby@gmail.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      72ed7de7
    • Rusty Russell's avatar
      x86: Side-step lguest problem by only building cmpxchg8b_emu for pre-Pentium · ae1b22f6
      Rusty Russell authored 
      Commit 79e1dd05 "x86: Provide an alternative() based
cmpxchg64()" broke lguest, even on systems which have cmpxchg8b
support.  The emulation code gets used until alternatives get
run, but it contains native instructions, not their paravirt
alternatives.

The simplest fix is to turn this code off except for 386 and 486
builds.
Reported-by: default avatarJohannes Stezenbach <js@sig21.net>
Signed-off-by: default avatarRusty Russell <rusty@rustcorp.com.au>
Acked-by: default avatarH. Peter Anvin <hpa@zytor.com>
Cc: lguest@ozlabs.org
Cc: Arjan van de Ven <arjan@infradead.org>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
LKML-Reference: <200910261426.05769.rusty@rustcorp.com.au>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      ae1b22f6
  27. 23 Oct, 2009 1 commit
  29. 21 Oct, 2009 1 commit
  31. 16 Oct, 2009 5 commits
    • Robin Holt's avatar
      x86, UV: Fix and clean up bau code to use uv_gpa_to_pnode() · 1d21e6e3
      Robin Holt authored 
      Create an inline function to extract the pnode from a global
physical address and then convert the broadcast assist unit to
use the newly created uv_gpa_to_pnode function.

The open-coded code was wrong as well - it might explain a
few of our unexplained bau hangs.
Signed-off-by: default avatarRobin Holt <holt@sgi.com>
Acked-by: default avatarCliff Whickman <cpw@sgi.com>
Cc: linux-mm@kvack.org
Cc: Jack Steiner <steiner@sgi.com>
LKML-Reference: <20091016112920.GZ8903@sgi.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      1d21e6e3
    • Roland Dreier's avatar
      x86: Don't print number of MCE banks for every CPU · 93ae5012
      Roland Dreier authored 
      The MCE initialization code explicitly says it doesn't handle
asymmetric configurations where different CPUs support different
numbers of MCE banks, and it prints a big warning in that case.

Therefore, printing the "mce: CPU supports <x> MCE banks"
message into the kernel log for every CPU is pure redundancy
that clutters the log significantly for systems with lots of
CPUs.
Signed-off-by: default avatarRoland Dreier <rolandd@cisco.com>
LKML-Reference: <adaeip473qt.fsf@cisco.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      93ae5012
    • Robin Holt's avatar
      x86, UV: Fix information in __uv_hub_info structure · 036ed8ba
      Robin Holt authored 
      A few parts of the uv_hub_info structure are initialized
incorrectly.

 - n_val is being loaded with m_val.
 - gpa_mask is initialized with a bytes instead of an unsigned long.
 - Handle the case where none of the alias registers are used.

Lastly I converted the bau over to using the uv_hub_info->m_val
which is the correct value.

Without this patch, booting a large configuration hits a
problem where the upper bits of the gnode affect the pnode
and the bau will not operate.
Signed-off-by: default avatarRobin Holt <holt@sgi.com>
Acked-by: default avatarJack Steiner <steiner@sgi.com>
Cc: Cliff Whickman <cpw@sgi.com>
Cc: stable@kernel.org
LKML-Reference: <20091015224946.396355000@alcatraz.americas.sgi.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      036ed8ba
    • Ingo Molnar's avatar
      x86: Document linker script ASSERT() quirk · a5912f6b
      Ingo Molnar authored 
      Older binutils breaks if ASSERT() is used without a sink
for the output.

For example 2.14.90.0.6 is known to be broken, the link
fails with:

  LD      .tmp_vmlinux1
  ld:arch/x86/kernel/vmlinux.lds:678: parse error

Document this quirk in all three files that use it.

  See:    http://marc.info/?l=linux-kbuild&m=124930110427870&w=2
  See[2]: d2ba8b21 ("x86: Fix assert syntax in vmlinux.lds.S")

Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Roland McGrath <roland@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
LKML-Reference: <4AD6523D.5030909@zytor.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      a5912f6b
    • Linus Torvalds's avatar
      Linux 2.6.32-rc5 · 012abeea
      Linus Torvalds authored
      012abeea
  33. 15 Oct, 2009 14 commits
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