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2009-01-27Merge branch 'tj-percpu' of ↵Ingo Molnar
git://git.kernel.org/pub/scm/linux/kernel/git/tj/misc into core/percpu Conflicts: arch/x86/kernel/setup_percpu.c Semantic conflict: arch/x86/kernel/cpu/common.c Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-27Merge branch 'linus' into core/percpuIngo Molnar
Conflicts: arch/x86/kernel/setup_percpu.c
2009-01-27x86: clean up indentation in setup_per_cpu_areas()Tejun Heo
Impact: cosmetic cleanup Signed-off-by: Tejun Heo <tj@kernel.org>
2009-01-27x86: fix build breakage on voyageJames Bottomley
Impact: build fix x86_cpu_to_apicid and x86_bios_cpu_apicid aren't defined for voyage. Earlier patch forgot to conditionalize early percpu clearing. Fix it. Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2009-01-27x86: load new GDT after setting up boot cpu per-cpu areaBrian Gerst
Impact: sync 32 and 64-bit code Merge load_gs_base() into switch_to_new_gdt(). Load the GDT and per-cpu state for the boot cpu when its new area is set up. Signed-off-by: Brian Gerst <brgerst@gmail.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2009-01-27x86: remove extra barriers from load_gs_base()Brian Gerst
Impact: optimization mb() generates an mfence instruction, which is not needed here. Only a compiler barrier is needed, and that is handled by the memory clobber in the wrmsrl function. Signed-off-by: Brian Gerst <brgerst@gmail.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2009-01-27x86: initialize per-cpu GDT segment in per-cpu setupBrian Gerst
Impact: cleanup Rename init_gdt() to setup_percpu_segment(), and move it to setup_percpu.c. Signed-off-by: Brian Gerst <brgerst@gmail.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2009-01-27x86: make Voyager use x86 per-cpu setup.Brian Gerst
Impact: standardize all x86 platforms on same setup code With the preceding changes, Voyager can use the same per-cpu setup code as all the other x86 platforms. Signed-off-by: Brian Gerst <brgerst@gmail.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2009-01-27x86: don't assume boot cpu is #0Brian Gerst
Impact: minor cleanup Signed-off-by: Brian Gerst <brgerst@gmail.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2009-01-27x86: move this_cpu_offsetBrian Gerst
Impact: Small cleanup Define BOOT_PERCPU_OFFSET and use it for this_cpu_offset and __per_cpu_offset initializers. Signed-off-by: Brian Gerst <brgerst@gmail.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2009-01-27x86: only compile setup_percpu.o on SMPBrian Gerst
Impact: Minor build optimization Signed-off-by: Brian Gerst <brgerst@gmail.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2009-01-27x86: move apic variables to apic.cBrian Gerst
Impact: Code movement Move the variable definitions to apic.c. Ifdef the copying of the two early per-cpu variables, since Voyager doesn't use them. Signed-off-by: Brian Gerst <brgerst@gmail.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2009-01-27x86: always page-align per-cpu area start and sizeBrian Gerst
Impact: cleanup The way the code is written, align is always PAGE_SIZE. Simplify the code by removing the align variable. Signed-off-by: Brian Gerst <brgerst@gmail.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2009-01-27x86: move setup_cpu_local_masks()Brian Gerst
Impact: Code movement, no functional change. Move setup_cpu_local_masks() to kernel/cpu/common.c, where the masks are defined. Signed-off-by: Brian Gerst <brgerst@gmail.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2009-01-27x86: move 64-bit NUMA codeBrian Gerst
Impact: Code movement, no functional change. Move the 64-bit NUMA code from setup_percpu.c to numa_64.c Signed-off-by: Brian Gerst <brgerst@gmail.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2009-01-27x86: merge setup_per_cpu_maps() into setup_per_cpu_areas()Brian Gerst
Impact: minor optimization Eliminates the need for two loops over possible cpus. Signed-off-by: Brian Gerst <brgerst@gmail.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2009-01-26Merge branch 'i2c-for-linus' of git://jdelvare.pck.nerim.net/jdelvare-2.6Linus Torvalds
* 'i2c-for-linus' of git://jdelvare.pck.nerim.net/jdelvare-2.6: i2c: Warn on deprecated binding model use eeprom: More consistent symbol names eeprom: Move 93cx6 eeprom driver to /drivers/misc/eeprom spi: Move at25 (for SPI eeproms) to /drivers/misc/eeprom i2c: Move old eeprom driver to /drivers/misc/eeprom i2c: Move at24 to drivers/misc/eeprom i2c: Quilt tree has moved i2c: Delete many unused adapter IDs i2c: Delete 10 unused driver IDs
2009-01-26Merge git://git.kernel.org/pub/scm/linux/kernel/git/sam/kbuild-fixesLinus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/sam/kbuild-fixes: kbuild: fix kbuild.txt typos kbuild: print usage with no arguments in scripts/config Revert "kbuild: strip generated symbols from *.ko"
2009-01-26eeprom: More consistent symbol namesJean Delvare
Now that all EEPROM drivers live in the same place, let's harmonize their symbol names. Also fix eeprom's dependencies, it definitely needs sysfs, and is no longer experimental after many years in the kernel tree. Signed-off-by: Jean Delvare <khali@linux-fr.org> Acked-by: Wolfram Sang <w.sang@pengutronix.de> Cc: David Brownell <dbrownell@users.sourceforge.net>
2009-01-26Merge branch 'core-fixes-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: debugobjects: add and use INIT_WORK_ON_STACK rcu: remove duplicate CONFIG_RCU_CPU_STALL_DETECTOR relay: fix lock imbalance in relay_late_setup_files oprofile: fix uninitialized use of struct op_entry rcu: move Kconfig menu softlock: fix false panic which can occur if softlockup_thresh is reduced rcu: add __cpuinit to rcu_init_percpu_data()
2009-01-26Merge branch 'timers-fixes-for-linus' of ↵Linus Torvalds
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: hrtimers: fix inconsistent lock state on resume in hres_timers_resume time-sched.c: tick_nohz_update_jiffies should be static locking, hpet: annotate false positive warning kernel/fork.c: unused variable 'ret' itimers: remove the per-cpu-ish-ness
2009-01-26Merge branch 'x86-fixes-for-linus' of ↵Linus Torvalds
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: (29 commits) xen: unitialised return value in xenbus_write_transaction x86: fix section mismatch warning x86: unmask CPUID levels on Intel CPUs, fix x86: work around PAGE_KERNEL_WC not getting WC in iomap_atomic_prot_pfn. x86: use standard PIT frequency xen: handle highmem pages correctly when shrinking a domain x86, mm: fix pte_free() xen: actually release memory when shrinking domain x86: unmask CPUID levels on Intel CPUs x86: add MSR_IA32_MISC_ENABLE bits to <asm/msr-index.h> x86: fix PTE corruption issue while mapping RAM using /dev/mem x86: mtrr fix debug boot parameter x86: fix page attribute corruption with cpa() Revert "x86: signal: change type of paramter for sys_rt_sigreturn()" x86: use early clobbers in usercopy*.c x86: remove kernel_physical_mapping_init() from init section fix: crash: IP: __bitmap_intersects+0x48/0x73 cpufreq: use work_on_cpu in acpi-cpufreq.c for drv_read and drv_write work_on_cpu: Use our own workqueue. work_on_cpu: don't try to get_online_cpus() in work_on_cpu. ...
2009-01-26x86: fix section mismatch warningRakib Mullick
Here function vmi_activate calls a init function activate_vmi , which causes the following section mismatch warnings: LD arch/x86/kernel/built-in.o WARNING: arch/x86/kernel/built-in.o(.text+0x13ba9): Section mismatch in reference from the function vmi_activate() to the function .init.text:vmi_time_init() The function vmi_activate() references the function __init vmi_time_init(). This is often because vmi_activate lacks a __init annotation or the annotation of vmi_time_init is wrong. WARNING: arch/x86/kernel/built-in.o(.text+0x13bd1): Section mismatch in reference from the function vmi_activate() to the function .devinit.text:vmi_time_bsp_init() The function vmi_activate() references the function __devinit vmi_time_bsp_init(). This is often because vmi_activate lacks a __devinit annotation or the annotation of vmi_time_bsp_init is wrong. WARNING: arch/x86/kernel/built-in.o(.text+0x13bdb): Section mismatch in reference from the function vmi_activate() to the function .devinit.text:vmi_time_ap_init() The function vmi_activate() references the function __devinit vmi_time_ap_init(). This is often because vmi_activate lacks a __devinit annotation or the annotation of vmi_time_ap_init is wrong. Fix it by marking vmi_activate() as __init too. Signed-off-by: Rakib Mullick <rakib.mullick@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-26x86: unmask CPUID levels on Intel CPUs, fixIngo Molnar
Impact: fix boot hang on pre-model-15 Intel CPUs rdmsrl_safe() does not work in very early bootup code yet, because we dont have the pagefault handler installed yet so exception section does not get parsed. rdmsr_safe() will just crash and hang the bootup. So limit the MSR_IA32_MISC_ENABLE MSR read to those CPU types that support it. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-26x86: work around PAGE_KERNEL_WC not getting WC in iomap_atomic_prot_pfn.Eric Anholt
In the absence of PAT, PAGE_KERNEL_WC ends up mapping to a memory type that gets UC behavior even in the presence of a WC MTRR covering the area in question. By swapping to PAGE_KERNEL_UC_MINUS, we can get the actual behavior the caller wanted (WC if you can manage it, UC otherwise). This recovers the 40% performance improvement of using WC in the DRM to upload vertex data. Signed-off-by: Eric Anholt <eric@anholt.net> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-01-25x86: use standard PIT frequencyIngo Molnar
the RDC and ELAN platforms use slighly different PIT clocks, resulting in a timex.h hack that changes PIT_TICK_RATE during build time. But if a tester enables any of these platform support .config options, the PIT will be miscalibrated on standard PC platforms. So use one frequency - in a subsequent patch we'll add a quirk to allow x86 platforms to define different PIT frequencies. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-23x86, mm: fix pte_free()Peter Zijlstra
On -rt we were seeing spurious bad page states like: Bad page state in process 'firefox' page:c1bc2380 flags:0x40000000 mapping:c1bc2390 mapcount:0 count:0 Trying to fix it up, but a reboot is needed Backtrace: Pid: 503, comm: firefox Not tainted 2.6.26.8-rt13 #3 [<c043d0f3>] ? printk+0x14/0x19 [<c0272d4e>] bad_page+0x4e/0x79 [<c0273831>] free_hot_cold_page+0x5b/0x1d3 [<c02739f6>] free_hot_page+0xf/0x11 [<c0273a18>] __free_pages+0x20/0x2b [<c027d170>] __pte_alloc+0x87/0x91 [<c027d25e>] handle_mm_fault+0xe4/0x733 [<c043f680>] ? rt_mutex_down_read_trylock+0x57/0x63 [<c043f680>] ? rt_mutex_down_read_trylock+0x57/0x63 [<c0218875>] do_page_fault+0x36f/0x88a This is the case where a concurrent fault already installed the PTE and we get to free the newly allocated one. This is due to pgtable_page_ctor() doing the spin_lock_init(&page->ptl) which is overlaid with the {private, mapping} struct. union { struct { unsigned long private; struct address_space *mapping; }; spinlock_t ptl; struct kmem_cache *slab; struct page *first_page; }; Normally the spinlock is small enough to not stomp on page->mapping, but PREEMPT_RT=y has huge 'spin'locks. But lockdep kernels should also be able to trigger this splat, as the lock tracking code grows the spinlock to cover page->mapping. The obvious fix is calling pgtable_page_dtor() like the regular pte free path __pte_free_tlb() does. It seems all architectures except x86 and nm10300 already do this, and nm10300 doesn't seem to use pgtable_page_ctor(), which suggests it doesn't do SMP or simply doesnt do MMU at all or something. Signed-off-by: Peter Zijlstra <a.p.zijlsta@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu> Cc: <stable@kernel.org>
2009-01-23x86, xen: fix hardirq.h merge falloutIngo Molnar
Impact: build fix This build error: arch/x86/xen/suspend.c:22: error: implicit declaration of function 'fix_to_virt' arch/x86/xen/suspend.c:22: error: 'FIX_PARAVIRT_BOOTMAP' undeclared (first use in this function) arch/x86/xen/suspend.c:22: error: (Each undeclared identifier is reported only once arch/x86/xen/suspend.c:22: error: for each function it appears in.) triggers because the hardirq.h unification removed an implicit fixmap.h include - on which arch/x86/xen/suspend.c depended. Add the fixmap.h include explicitly. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-23x86: make irq_cpustat_t fields conditionalBrian Gerst
Impact: shrink size of irq_cpustat_t when possible Signed-off-by: Brian Gerst <brgerst@gmail.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2009-01-23x86: merge hardirq_{32,64}.h into hardirq.hBrian Gerst
Impact: cleanup Signed-off-by: Brian Gerst <brgerst@gmail.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2009-01-23x86: sync hardirq_{32,64}.hBrian Gerst
Impact: better code generation and removal of unused field for 32bit In general, use the 64-bit version. Signed-off-by: Brian Gerst <brgerst@gmail.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2009-01-23x86: remove include of apic.h from hardirq_64.hBrian Gerst
Impact: cleanup APIC definitions aren't needed here. Remove the include and fix up the fallout. tj: added include to mce_intel_64.c. Signed-off-by: Brian Gerst <brgerst@gmail.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2009-01-23x86: remove idle_timestamp from 32bit irq_cpustat_tBrian Gerst
Impact: bogus irq_cpustat field removed idle_timestamp is left over from the removed irqbalance code. Signed-off-by: Brian Gerst <brgerst@gmail.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2009-01-22debugobjects: add and use INIT_WORK_ON_STACKThomas Gleixner
Impact: Fix debugobjects warning debugobject enabled kernels spit out a warning in hpet code due to a workqueue which is initialized on stack. Add INIT_WORK_ON_STACK() which calls init_timer_on_stack() and use it in hpet. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2009-01-22x86: unmask CPUID levels on Intel CPUsH. Peter Anvin
Impact: Fixes crashes with misconfigured BIOSes on XSAVE hardware Avuton Olrich reported early boot crashes with v2.6.28 and bisected it down to dc1e35c6e95e8923cf1d3510438b63c600fee1e2 ("x86, xsave: enable xsave/xrstor on cpus with xsave support"). If the CPUID limit bit in MSR_IA32_MISC_ENABLE is set, clear it to make all CPUID information available. This is required for some features to work, in particular XSAVE. Reported-and-bisected-by: Avuton Olrich <avuton@gmail.com> Tested-by: Avuton Olrich <avuton@gmail.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2009-01-21x86: add MSR_IA32_MISC_ENABLE bits to <asm/msr-index.h>H. Peter Anvin
Impact: None (new bit definitions currently unused) Add bit definitions for the MSR_IA32_MISC_ENABLE MSRs to <asm/msr-index.h>. Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2009-01-21x86: fix PTE corruption issue while mapping RAM using /dev/memSuresh Siddha
Beschorner Daniel reported: > hwinfo problem since 2.6.28, showing this in the oops: > Corrupted page table at address 7fd04de3ec00 Also, PaX Team reported a regression with this commit: > commit 9542ada803198e6eba29d3289abb39ea82047b92 > Author: Suresh Siddha <suresh.b.siddha@intel.com> > Date: Wed Sep 24 08:53:33 2008 -0700 > > x86: track memtype for RAM in page struct This commit breaks mapping any RAM page through /dev/mem, as the reserve_memtype() was not initializing the return attribute type and as such corrupting the PTE entry that was setup with the return attribute type. Because of this bug, application mapping this RAM page through /dev/mem will die with "Corrupted page table at address xxxx" message in the kernel log and also the kernel identity mapping which maps the underlying RAM page gets converted to UC. Fix this by initializing the return attribute type before calling reserve_ram_pages_type() Reported-by: PaX Team <pageexec@freemail.hu> Reported-and-tested-by: Beschorner Daniel <Daniel.Beschorner@facton.com> Tested-and-Acked-by: PaX Team <pageexec@freemail.hu> 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>
2009-01-21x86: make UV support configurableNick Piggin
Make X86 SGI Ultraviolet support configurable. Saves about 13K of text size on my modest config. text data bss dec hex filename 6770537 1158680 694356 8623573 8395d5 vmlinux 6757492 1157664 694228 8609384 835e68 vmlinux.nouv Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-21x86: mtrr fix debug boot parameterThomas Renninger
while looking at: http://bugzilla.kernel.org/show_bug.cgi?id=11541 I realized that the mtrr.show param cannot work, because the code is processed much too early. This patch: - Declares mtrr.show as early_param - Stays consistent with the previous param (which I doubt that it ever worked), so mtrr.show=1 would still work - Declares mtrr_show as initdata Signed-off-by: Thomas Renninger <trenn@suse.de> Acked-by: Jan Beulich <jbeulich@novell.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-21x86: fix page attribute corruption with cpa()Suresh Siddha
Impact: fix sporadic slowdowns and warning messages This patch fixes a performance issue reported by Linus on his Nehalem system. While Linus reverted the PAT patch (commit 58dab916dfb57328d50deb0aa9b3fc92efa248ff) which exposed the issue, existing cpa() code can potentially still cause wrong(page attribute corruption) behavior. This patch also fixes the "WARNING: at arch/x86/mm/pageattr.c:560" that various people reported. In 64bit kernel, kernel identity mapping might have holes depending on the available memory and how e820 reports the address range covering the RAM, ACPI, PCI reserved regions. If there is a 2MB/1GB hole in the address range that is not listed by e820 entries, kernel identity mapping will have a corresponding hole in its 1-1 identity mapping. If cpa() happens on the kernel identity mapping which falls into these holes, existing code fails like this: __change_page_attr_set_clr() __change_page_attr() returns 0 because of if (!kpte). But doesn't set cpa->numpages and cpa->pfn. cpa_process_alias() uses uninitialized cpa->pfn (random value) which can potentially lead to changing the page attribute of kernel text/data, kernel identity mapping of RAM pages etc. oops! This bug was easily exposed by another PAT patch which was doing cpa() more often on kernel identity mapping holes (physical range between max_low_pfn_mapped and 4GB), where in here it was setting the cache disable attribute(PCD) for kernel identity mappings aswell. Fix cpa() to handle the kernel identity mapping holes. Retain the WARN() for cpa() calls to other not present address ranges (kernel-text/data, ioremap() addresses) Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Cc: <stable@kernel.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-21x86: make x86_32 use tlb_64.c, build fix, clean up X86_L1_CACHE_BYTESIngo Molnar
Fix: arch/x86/mm/tlb.c:47: error: ‘CONFIG_X86_INTERNODE_CACHE_BYTES’ undeclared here (not in a function) The CONFIG_X86_INTERNODE_CACHE_BYTES symbol is only defined on 64-bit, because vsmp support is 64-bit only. Define it on 32-bit too - where it will always be equal to X86_L1_CACHE_BYTES. Also move the default of X86_L1_CACHE_BYTES (which is separate from the more commonly used L1_CACHE_SHIFT kconfig symbol) from 128 bytes to 64 bytes. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-21Merge branch 'x86/mm' into core/percpuIngo Molnar
Conflicts: arch/x86/mm/fault.c
2009-01-21x86: uv cleanup, build fixIngo Molnar
Fix: arch/x86/mm/srat_64.c: In function ‘acpi_numa_processor_affinity_init’: arch/x86/mm/srat_64.c:141: error: implicit declaration of function ‘get_uv_system_type’ arch/x86/mm/srat_64.c:141: error: ‘UV_X2APIC’ undeclared (first use in this function) arch/x86/mm/srat_64.c:141: error: (Each undeclared identifier is reported only once arch/x86/mm/srat_64.c:141: error: for each function it appears in.) A couple of UV definitions were moved to asm/uv/uv.h, but srat_64.c did not include that header. Add it. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-21x86, mm: move tlb.c to arch/x86/mm/Ingo Molnar
Impact: cleanup Now that it's unified, move the (SMP) TLB flushing code from arch/x86/kernel/ to arch/x86/mm/, where it belongs logically. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-21Merge branch 'cpus4096' into core/percpuIngo Molnar
Conflicts: arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c arch/x86/kernel/tlb_32.c Merge it here because both the cpumask changes and the ongoing percpu work is touching the TLB code. The percpu changes take precedence, as they eliminate tlb_32.c altogether. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-21Revert "x86: signal: change type of paramter for sys_rt_sigreturn()"Ingo Molnar
This reverts commit 4217458dafaa57d8e26a46f5d05ab8c53cf64191. Justin Madru bisected this commit, it was causing weird Firefox crashes. The reason is that GCC mis-optimizes (re-uses) the on-stack parameters of the calling frame, which corrupts the syscall return pt_regs state and thus corrupts user-space register state. So we go back to the slightly less clean but more optimization-safe method of getting to pt_regs. Also add a comment to explain this. Resolves: http://bugzilla.kernel.org/show_bug.cgi?id=12505 Reported-and-bisected-by: Justin Madru <jdm64@gawab.com> Tested-by: Justin Madru <jdm64@gawab.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-21x86: use early clobbers in usercopy*.cAndi Kleen
Impact: fix rare (but currently harmless) miscompile with certain configs and gcc versions Hugh Dickins noticed that strncpy_from_user() was miscompiled in some circumstances with gcc 4.3. Thanks to Hugh's excellent analysis it was easy to track down. Hugh writes: > Try building an x86_64 defconfig 2.6.29-rc1 kernel tree, > except not quite defconfig, switch CONFIG_PREEMPT_NONE=y > and CONFIG_PREEMPT_VOLUNTARY off (because it expands a > might_fault() there, which hides the issue): using a > gcc 4.3.2 (I've checked both openSUSE 11.1 and Fedora 10). > > It generates the following: > > 0000000000000000 <__strncpy_from_user>: > 0: 48 89 d1 mov %rdx,%rcx > 3: 48 85 c9 test %rcx,%rcx > 6: 74 0e je 16 <__strncpy_from_user+0x16> > 8: ac lods %ds:(%rsi),%al > 9: aa stos %al,%es:(%rdi) > a: 84 c0 test %al,%al > c: 74 05 je 13 <__strncpy_from_user+0x13> > e: 48 ff c9 dec %rcx > 11: 75 f5 jne 8 <__strncpy_from_user+0x8> > 13: 48 29 c9 sub %rcx,%rcx > 16: 48 89 c8 mov %rcx,%rax > 19: c3 retq > > Observe that "sub %rcx,%rcx; mov %rcx,%rax", whereas gcc 4.2.1 > (and many other configs) say "sub %rcx,%rdx; mov %rdx,%rax". > Isn't it returning 0 when it ought to be returning strlen? The asm constraints for the strncpy_from_user() result were missing an early clobber, which tells gcc that the last output arguments are written before all input arguments are read. Also add more early clobbers in the rest of the file and fix 32-bit usercopy.c in the same way. Signed-off-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com> [ since this API is rarely used and no in-kernel user relies on a 'len' return value (they only rely on negative return values) this miscompile was never noticed in the field. But it's worth fixing it nevertheless. ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-21x86: rename tlb_64.c to tlb.cTejun Heo
Impact: file rename tlb_64.c is now the tlb code for both 32 and 64. Rename it to tlb.c. Signed-off-by: Tejun Heo <tj@kernel.org>
2009-01-21x86: make x86_32 use tlb_64.cTejun Heo
Impact: less contention when issuing invalidate IPI, cleanup Make x86_32 use the same tlb code as 64bit. The 64bit code uses multiple IPI vectors for tlb shootdown to reduce contention. This patch makes x86_32 allocate the same 8 IPIs as x86_64 and share the code paths. Note that the usage of asmlinkage is inconsistent for x86_32 and 64 and calls for further cleanup. This has been noted with a FIXME comment in tlb_64.c. Signed-off-by: Tejun Heo <tj@kernel.org>
2009-01-21x86: prepare for tlb mergeTejun Heo
Impact: clean up, ipi vector number reordering for x86_32 Make the following changes to prepare for tlb merge. * reorder x86_32 ip vectors * adjust tlb_32.c and tlb_64.c such that their logics coincide exactly - on spurious invalidate ipi, tlb_32 acks the irq - tlb_64 now has proper memory barriers around clearing flush_cpumask (no change in generated code) * unexport flush_tlb_page from tlb_32.c, there's no user * use unsigned int for cpu id * drop unnecessary includes from tlb_64.c Signed-off-by: Tejun Heo <tj@kernel.org>