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6228 commits

Author SHA1 Message Date
Ian Campbell b93d51dc62 x86, xen: record and display initiator of each multicall when debugging
Store the caller for each multicall so we can report it on failure.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-16 08:56:11 +01:00
Jeremy Fitzhardinge 9033304a15 x86, xen: short-circuit tests for dom0
When testing for a dom0/initial/privileged domain, make sure the
predicate evaluates to a compile-time 0 if CONFIG_XEN_DOM0 isn't
enabled.  This will make most of the dom0 code evaporate without
much more effort.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-16 08:55:50 +01:00
Ingo Molnar 7032e86967 Merge branches 'x86/paravirt', 'x86/pat', 'x86/setup-v2', 'x86/subarch', 'x86/uaccess' and 'x86/urgent' into x86/core 2009-02-13 09:47:32 +01:00
Ingo Molnar f268fe7333 Merge branch 'x86/mm' into x86/core 2009-02-13 09:47:24 +01:00
Ingo Molnar a56cdcb662 Merge branches 'x86/acpi', 'x86/asm', 'x86/cpudetect', 'x86/crashdump', 'x86/debug', 'x86/defconfig', 'x86/doc', 'x86/header-fixes', 'x86/headers' and 'x86/minor-fixes' into x86/core 2009-02-13 09:46:36 +01:00
Ingo Molnar 881c47760b Merge branch 'x86/cleanups' into x86/core 2009-02-13 09:45:42 +01:00
Ingo Molnar ab639f3593 Merge branch 'core/percpu' into x86/core 2009-02-13 09:45:09 +01:00
Ingo Molnar f8a6b2b9ce Merge branch 'linus' into x86/apic
Conflicts:
	arch/x86/kernel/acpi/boot.c
	arch/x86/mm/fault.c
2009-02-13 09:44:22 +01:00
john stultz b13e24644c x86, hpet: fix for LS21 + HPET = boot hang
Between 2.6.23 and 2.6.24-rc1 a change was made that broke IBM LS21
systems that had the HPET enabled in the BIOS, resulting in boot hangs
for x86_64.

Specifically commit b8ce335906, which
merges the i386 and x86_64 HPET code.

Prior to this commit, when we setup the HPET timers in x86_64, we did
the following:

	hpet_writel(HPET_TN_ENABLE | HPET_TN_PERIODIC | HPET_TN_SETVAL |
                    HPET_TN_32BIT, HPET_T0_CFG);

However after the i386/x86_64 HPET merge, we do the following:

	cfg = hpet_readl(HPET_Tn_CFG(timer));
	cfg |= HPET_TN_ENABLE | HPET_TN_PERIODIC |
			HPET_TN_SETVAL | HPET_TN_32BIT;
	hpet_writel(cfg, HPET_Tn_CFG(timer));

However on LS21s with HPET enabled in the BIOS, the HPET_T0_CFG register
boots with Level triggered interrupts (HPET_TN_LEVEL) enabled. This
causes the periodic interrupt to be not so periodic, and that results in
the boot time hang I reported earlier in the delay calibration.

My fix: Always disable HPET_TN_LEVEL when setting up periodic mode.

Signed-off-by: John Stultz <johnstul@us.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-13 09:15:46 +01:00
Thomas Gleixner 7ad9de6ac8 x86: CPA avoid repeated lazy mmu flush
Impact: Flush the lazy MMU only once

Pending mmu updates only need to be flushed once to bring the
in-memory pagetable state up to date.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2009-02-12 23:11:58 +01:00
Thomas Gleixner 34b0900d32 x86: warn if arch_flush_lazy_mmu_cpu is called in preemptible context
Impact: Catch cases where lazy MMU state is active in a preemtible context

arch_flush_lazy_mmu_cpu() has been changed to disable preemption so
the checks in enter/leave will never trigger. Put the preemtible()
check into arch_flush_lazy_mmu_cpu() to catch such cases.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2009-02-12 23:11:58 +01:00
Jeremy Fitzhardinge d85cf93da6 x86/paravirt: make arch_flush_lazy_mmu/cpu disable preemption
Impact: avoid access to percpu vars in preempible context

They are intended to be used whenever there's the possibility
that there's some stale state which is going to be overwritten
with a queued update, or to force a state change when we may be
in lazy mode.  Either way, we could end up calling it with
preemption enabled, so wrap the functions in their own little
preempt-disable section so they can be safely called in any
context (though preemption should never be enabled if we're actually
in a lazy state).

(Move out of line to avoid #include dependencies.)
    
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2009-02-12 23:11:58 +01:00
Ingo Molnar d88316c243 x86, 32-bit: refactor find_low_pfn_range()
Impact: cleanup

Make the max_low_pfn logic a bit more standard between
lowmem_pfn_init() and highmem_pfn_init().

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-12 15:21:17 +01:00
Ingo Molnar 4769843bc2 x86, 32-bit: clean up find_low_pfn_range()
Impact: cleanup

Split find_low_pfn_range() into two functions:

 - lowmem_pfn_init()
 - highmem_pfn_init()

The former gets called if all of RAM fits into lowmem,
otherwise we call highmem_pfn_init().

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-12 15:21:16 +01:00
Ingo Molnar 3023533de4 x86: fix warning in find_low_pfn_range()
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-12 15:21:15 +01:00
Ingo Molnar bd282422fe x86, defconfig: turn off CONFIG_SCSI_ISCSI_ATTRS=y
It was enabled by mistake - iscsi is not included in a typical
default PC, and no other architecture has it built-in (=y) either.

Turn it off.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-12 13:06:43 +01:00
Ingo Molnar 556831063b x86, defconfig: turn off CONFIG_ENABLE_WARN_DEPRECATED
deprecation warnings have become rather noisy lately:

drivers/i2c/i2c-core.c: In function ‘i2c_new_device’:
drivers/i2c/i2c-core.c:283: warning: ‘i2c_attach_client’ is deprecated (declared at include/linux/i2c.h:434)
drivers/i2c/i2c-core.c: In function ‘i2c_del_adapter’:
drivers/i2c/i2c-core.c:646: warning: ‘detach_client’ is deprecated (declared at include/linux/i2c.h:154)
drivers/i2c/i2c-core.c: In function ‘i2c_register_driver’:
drivers/i2c/i2c-core.c:713: warning: ‘detach_client’ is deprecated (declared at include/linux/i2c.h:154)
drivers/i2c/i2c-core.c: In function ‘__detach_adapter’:
drivers/i2c/i2c-core.c:780: warning: ‘detach_client’ is deprecated (declared at include/linux/i2c.h:154)
drivers/i2c/i2c-core.c: At top level:
drivers/i2c/i2c-core.c:876: warning: ‘i2c_attach_client’ is deprecated (declared at drivers/i2c/i2c-core.c:827)
drivers/i2c/i2c-core.c:876: warning: ‘i2c_attach_client’ is deprecated (declared at drivers/i2c/i2c-core.c:827)
drivers/i2c/i2c-core.c:904: warning: ‘i2c_detach_client’ is deprecated (declared at drivers/i2c/i2c-core.c:879)
drivers/i2c/i2c-core.c:904: warning: ‘i2c_detach_client’ is deprecated (declared at drivers/i2c/i2c-core.c:879)

So turn it off for now - these reminders can obscure critical warnings.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-12 12:53:50 +01:00
Ingo Molnar dd5fc55449 x86, defconfig: update the 64-bit defconfig
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-12 12:48:48 +01:00
Ingo Molnar bc8bd002b8 x86, defconfig: update the 32-bit defconfig
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-12 12:43:52 +01:00
Suresh Siddha be03d9e802 x86, pat: fix warn_on_once() while mapping 0-1MB range with /dev/mem
Jeff Mahoney reported:

> With Suse's hwinfo tool, on -tip:
> WARNING: at arch/x86/mm/pat.c:637 reserve_pfn_range+0x5b/0x26d()

reserve_pfn_range() is not tracking the memory range below 1MB
as non-RAM and as such is inconsistent with similar checks in
reserve_memtype() and free_memtype()

Rename the pagerange_is_ram() to pat_pagerange_is_ram() and add the
"track legacy 1MB region as non RAM" condition.

And also, fix reserve_pfn_range() to return -EINVAL, when the pfn
range is RAM. This is to be consistent with this API design.

Reported-and-tested-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-12 08:27:27 +01:00
Jeremy Fitzhardinge 4f06b0436b x86/cpa: make sure cpa is safe to call in lazy mmu mode
Impact: fix race leading to crash under KVM and Xen

The CPA code may be called while we're in lazy mmu update mode - for
example, when using DEBUG_PAGE_ALLOC and doing a slab allocation
in an interrupt handler which interrupted a lazy mmu update.  In this
case, the in-memory pagetable state may be out of date due to pending
queued updates.  We need to flush any pending updates before inspecting
the page table.  Similarly, we must explicitly flush any modifications
CPA may have made (which comes down to flushing queued operations when
flushing the TLB).

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Acked-by: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Stable Kernel <stable@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-12 08:27:26 +01:00
Randy Dunlap 58105ef185 x86: UV: fix header struct usage
Impact: Fixes warning

Fix uv.h struct usage:

arch/x86/include/asm/uv/uv.h:16: warning: 'struct mm_struct' declared inside parameter list
arch/x86/include/asm/uv/uv.h:16: warning: its scope is only this definition or declaration, which is probably not what you want

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2009-02-11 17:17:29 -08:00
H. Peter Anvin 7445250927 x86: merge sys_rt_sigreturn between 32 and 64 bits
Impact: cleanup

With the recent changes in the 32-bit code to make system calls which
use struct pt_regs take a pointer, sys_rt_sigreturn() have become
identical between 32 and 64 bits, and both are empty wrappers around
do_rt_sigreturn().  Remove both wrappers and rename both to
sys_rt_sigreturn().

Cc: Brian Gerst <brgerst@gmail.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2009-02-11 16:31:40 -08:00
Brian Gerst b12bdaf11f x86: use regparm(3) for passed-in pt_regs pointer
Some syscalls need to access the pt_regs structure, either to copy
user register state or to modifiy it.  This patch adds stubs to load
the address of the pt_regs struct into the %eax register, and changes
the syscalls to take the pointer as an argument instead of relying on
the assumption that the pt_regs structure overlaps the function
arguments.

Drop the use of regparm(1) due to concern about gcc bugs, and to move
in the direction of the eventual removal of regparm(0) for asmlinkage.

Signed-off-by: Brian Gerst <brgerst@gmail.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2009-02-11 14:00:56 -08:00
Jaswinder Singh Rajput ba1511bf7f x86: kernel/mpparse.c fix compilation warnings
arch/x86/kernel/mpparse.c: In function ‘smp_scan_config’:
 arch/x86/kernel/mpparse.c:696: warning: format ‘%08lx’ expects type ‘long unsigned int’, but argument 3 has type ‘phys_addr_t’
 arch/x86/kernel/mpparse.c: In function ‘update_mp_table’:
 arch/x86/kernel/mpparse.c:1014: warning: format ‘%lx’ expects type ‘long unsigned int’, but argument 2 has type ‘phys_addr_t’

Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-11 21:01:08 +01:00
Jaswinder Singh Rajput 7651194fb7 x86: mm/init_32.c fix compilation warning
arch/x86/mm/init_32.c: In function ‘find_low_pfn_range’:
 arch/x86/mm/init_32.c:696: warning: format ‘%u’ expects type ‘unsigned int’, but

Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-11 21:00:47 +01:00
Linus Torvalds 94dba89533 Merge branch 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  timers: fix TIMER_ABSTIME for process wide cpu timers
  timers: split process wide cpu clocks/timers, fix
  x86: clean up hpet timer reinit
  timers: split process wide cpu clocks/timers, remove spurious warning
  timers: split process wide cpu clocks/timers
  signal: re-add dead task accumulation stats.
  x86: fix hpet timer reinit for x86_64
  sched: fix nohz load balancer on cpu offline
2009-02-11 08:24:32 -08:00
Linus Torvalds 9ce04f9238 Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  ptrace, x86: fix the usage of ptrace_fork()
  i8327: fix outb() parameter order
  x86: fix math_emu register frame access
  x86: math_emu info cleanup
  x86: include correct %gs in a.out core dump
  x86, vmi: put a missing paravirt_release_pmd in pgd_dtor
  x86: find nr_irqs_gsi with mp_ioapic_routing
  x86: add clflush before monitor for Intel 7400 series
  x86: disable intel_iommu support by default
  x86: don't apply __supported_pte_mask to non-present ptes
  x86: fix grammar in user-visible BIOS warning
  x86/Kconfig.cpu: make Kconfig help readable in the console
  x86, 64-bit: print DMI info in the oops trace
2009-02-11 08:23:22 -08:00
Ingo Molnar 17993b49b1 x86: make hibernation always-possible
This commit:

  aced3ce: x86/Voyager: remove HIBERNATION Kconfig quirk

Made hibernation only available on UP - instead of making it available
on all of x86. Fix it.

Reported-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-11 17:20:51 +01:00
Markus Metzger 9f339e7028 x86, ptrace, mm: fix double-free on race
Ptrace_detach() races with __ptrace_unlink() if the traced task is
reaped while detaching. This might cause a double-free of the BTS
buffer.

Change the ptrace_detach() path to only do the memory accounting in
ptrace_bts_detach() and leave the buffer free to ptrace_bts_untrace()
which will be called from __ptrace_unlink().

The fix follows a proposal from Oleg Nesterov.

Reported-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Markus Metzger <markus.t.metzger@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-11 15:44:20 +01:00
Ravikiran G Thirumalai c5c606d9dc x86: cleanup, rename CONFIG_X86_NON_STANDARD to CONFIG_X86_EXTENDED_PLATFORM
Patch to rename the CONFIG_X86_NON_STANDARD to CONFIG_X86_EXTENDED_PLATFORM.

The new name represents the subarches better. Also, default this to 'y'
so that many of the sub architectures that were not easily visible now
become visible.

Also re-organize the extended architecture platform and non standard
platform list alphabetically as suggested by Ingo.

Signed-off-by: Ravikiran Thirumalai <kiran@scalex86.org>
Signed-off-by: Shai Fultheim <shai@scalex86.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-11 14:17:40 +01:00
Brian Gerst 9c8bb6b534 x86: drop -fno-stack-protector annotations after pt_regs fixes
Now that no functions rely on struct pt_regs being passed by value,
various "no stack protector" annotations can be dropped.

Signed-off-by: Brian Gerst <brgerst@gmail.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-11 12:40:45 +01:00
Brian Gerst 253f29a4ae x86: pass in pt_regs pointer for syscalls that need it
Some syscalls need to access the pt_regs structure, either to copy
user register state or to modifiy it.  This patch adds stubs to load
the address of the pt_regs struct into the %eax register, and changes
the syscalls to regparm(1) to receive the pt_regs pointer as the
first argument.

Signed-off-by: Brian Gerst <brgerst@gmail.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-11 12:40:45 +01:00
Brian Gerst aa78bcfa01 x86: use pt_regs pointer in do_device_not_available()
The generic exception handler (error_code) passes in the pt_regs
pointer and the error code (unused in this case).  The commit
"x86: fix math_emu register frame access" changed this to pass by
value, which doesn't work correctly with stack protector enabled.
Change it back to use the pt_regs pointer.

Signed-off-by: Brian Gerst <brgerst@gmail.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-11 12:40:44 +01:00
Ingo Molnar 891393745a Merge commit 'v2.6.29-rc4' into x86/cleanups 2009-02-11 11:38:55 +01:00
Tejun Heo 5c79d2a517 x86: fix x86_32 stack protector bugs
Impact: fix x86_32 stack protector

Brian Gerst found out that %gs was being initialized to stack_canary
instead of stack_canary - 20, which basically gave the same canary
value for all threads.  Fixing this also exposed the following bugs.

* cpu_idle() didn't call boot_init_stack_canary()

* stack canary switching in switch_to() was being done too late making
  the initial run of a new thread use the old stack canary value.

Fix all of them and while at it update comment in cpu_idle() about
calling boot_init_stack_canary().

Reported-by: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-11 11:33:49 +01:00
Ingo Molnar 160d8dac12 x86, apic: make generic_apic_probe() generally available
Impact: build fix

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-11 11:27:39 +01:00
Ingo Molnar d5b5a232b2 Merge branch 'x86/apic' of git://git.kernel.org/pub/scm/linux/kernel/git/jeremy/xen into x86/apic 2009-02-11 10:49:40 +01:00
Alok Kataria 0e81cb59c7 x86, apic: fix initialization of wakeup_cpu
With refactoring of wake_cpu macros the 32bit code in tip doesn't
execute generic_apic_probe if CONFIG_X86_32_NON_STANDARD is not set.

Even on a x86 STANDARD cpu we need to execute the generic_apic_probe
function, as we rely on this function to execute the update_genapic
quirk which initilizes apic->wakeup_cpu.

Failing to do so results in we making a call to a null function in do_boot_cpu.

The stack trace without the patch goes like this.

Booting processor 1 APIC 0x1 ip 0x6000
BUG: unable to handle kernel NULL pointer dereference at (null)
IP: [<(null)>] (null)
*pdpt = 0000000000839001 *pde = 0000000000c97067 *pte = 0000000000000163
Oops: 0000 [#1] SMP
last sysfs file:
Modules linked in:

Pid: 1, comm: swapper Not tainted (2.6.29-rc4-tip #18) VMware Virtual Platform
EIP: 0062:[<00000000>] EFLAGS: 00010293 CPU: 0
EIP is at 0x0
EAX: 00000001 EBX: 00006000 ECX: c077ed00 EDX: 00006000
ESI: 00000001 EDI: 00000001 EBP: ef04cf40 ESP: ef04cf1c
 DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 006a
Process swapper (pid: 1, ti=ef04c000 task=ef050000 task.ti=ef04c000)
Stack:
 c0644e52 00000000 ef04cf24 ef04cf24 c064468d c0886dc0 00000000 c0702aea
 ef055480 00000001 00000101 dead4ead ffffffff ffffffff c08af530 00000000
 c0709715 ef04cf60 ef04cf60 00000001 00000000 00000000 dead4ead ffffffff
Call Trace:
 [<c0644e52>] ? native_cpu_up+0x2de/0x45b
 [<c064468d>] ? do_fork_idle+0x0/0x19
 [<c0645c5e>] ? _cpu_up+0x88/0xe8
 [<c0645d20>] ? cpu_up+0x42/0x4e
 [<c07e7462>] ? kernel_init+0x99/0x14b
 [<c07e73c9>] ? kernel_init+0x0/0x14b
 [<c040375f>] ? kernel_thread_helper+0x7/0x10
Code:  Bad EIP value.
EIP: [<00000000>] 0x0 SS:ESP 006a:ef04cf1c

I think we should call generic_apic_probe unconditionally for 32 bit now.

Signed-off-by: Alok N Kataria <akataria@vmware.com>
Acked-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-11 10:48:14 +01:00
Steven Rostedt f47a454db9 tracing, x86: fix constraint for parent variable
The constraint used for retrieving and restoring the parent function
pointer is incorrect. The parent variable is a pointer, and the
address of the pointer is modified by the asm statement and not
the pointer itself. It is incorrect to pass it in as an output
constraint since the asm will never update the pointer.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-11 10:06:13 +01:00
Steven Rostedt e3944bfac9 tracing, x86: fix fixup section to return to original code
Impact: fix to prevent a kernel crash on fault

If for some reason the pointer to the parent function on the
stack takes a fault, the fix up code will not return back to
the original faulting code. This can lead to unpredictable
results and perhaps even a kernel panic.

A fault should not happen, but if it does, we should simply
disable the tracer, warn, and continue running the kernel.
It should not lead to a kernel crash.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
2009-02-10 13:07:13 -05:00
Clemens Ladisch b52af40923 i8327: fix outb() parameter order
In i8237A_resume(), when resetting the DMA controller, the parameters to
dma_outb() were mixed up.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
[ cleaned up the file a tiny bit. ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-10 13:13:23 +01:00
Tejun Heo 60a5317ff0 x86: implement x86_32 stack protector
Impact: stack protector for x86_32

Implement stack protector for x86_32.  GDT entry 28 is used for it.
It's set to point to stack_canary-20 and have the length of 24 bytes.
CONFIG_CC_STACKPROTECTOR turns off CONFIG_X86_32_LAZY_GS and sets %gs
to the stack canary segment on entry.  As %gs is otherwise unused by
the kernel, the canary can be anywhere.  It's defined as a percpu
variable.

x86_32 exception handlers take register frame on stack directly as
struct pt_regs.  With -fstack-protector turned on, gcc copies the
whole structure after the stack canary and (of course) doesn't copy
back on return thus losing all changed.  For now, -fno-stack-protector
is added to all files which contain those functions.  We definitely
need something better.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-10 00:42:01 +01:00
Tejun Heo ccbeed3a05 x86: make lazy %gs optional on x86_32
Impact: pt_regs changed, lazy gs handling made optional, add slight
        overhead to SAVE_ALL, simplifies error_code path a bit

On x86_32, %gs hasn't been used by kernel and handled lazily.  pt_regs
doesn't have place for it and gs is saved/loaded only when necessary.
In preparation for stack protector support, this patch makes lazy %gs
handling optional by doing the followings.

* Add CONFIG_X86_32_LAZY_GS and place for gs in pt_regs.

* Save and restore %gs along with other registers in entry_32.S unless
  LAZY_GS.  Note that this unfortunately adds "pushl $0" on SAVE_ALL
  even when LAZY_GS.  However, it adds no overhead to common exit path
  and simplifies entry path with error code.

* Define different user_gs accessors depending on LAZY_GS and add
  lazy_save_gs() and lazy_load_gs() which are noop if !LAZY_GS.  The
  lazy_*_gs() ops are used to save, load and clear %gs lazily.

* Define ELF_CORE_COPY_KERNEL_REGS() which always read %gs directly.

xen and lguest changes need to be verified.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-10 00:42:00 +01:00
Tejun Heo d9a89a26e0 x86: add %gs accessors for x86_32
Impact: cleanup

On x86_32, %gs is handled lazily.  It's not saved and restored on
kernel entry/exit but only when necessary which usually is during task
switch but there are few other places.  Currently, it's done by
calling savesegment() and loadsegment() explicitly.  Define
get_user_gs(), set_user_gs() and task_user_gs() and use them instead.

While at it, clean up register access macros in signal.c.

This cleans up code a bit and will help future changes.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-10 00:41:58 +01:00
Tejun Heo f0d96110f9 x86: use asm .macro instead of cpp #define in entry_32.S
Impact: cleanup

Use .macro instead of cpp #define where approriate.  This cleans up
code and will ease future changes.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-10 00:41:57 +01:00
Tejun Heo d627ded5ab x86: no stack protector for vdso
Impact: avoid crash on vsyscall

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-10 00:41:56 +01:00
Tejun Heo 5d707e9c8e stackprotector: update make rules
Impact: no default -fno-stack-protector if stackp is enabled, cleanup

Stackprotector make rules had the following problems.

* cc support test and warning are scattered across makefile and
  kernel/panic.c.

* -fno-stack-protector was always added regardless of configuration.

Update such that cc support test and warning are contained in makefile
and -fno-stack-protector is added iff stackp is turned off.  While at
it, prepare for 32bit support.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-10 00:41:54 +01:00
Tejun Heo 76397f72fb x86: stackprotector.h misc update
Impact: misc udpate

* wrap content with CONFIG_CC_STACK_PROTECTOR so that other arch files
  can include it directly

* add missing includes

This will help future changes.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-10 00:41:29 +01:00
Ingo Molnar 92e2d50846 Merge branch 'x86/urgent' into core/percpu
Conflicts:
	arch/x86/kernel/acpi/boot.c
2009-02-10 00:41:02 +01:00