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* [PATCH] x86_64: Don't confuse noapic with noapictimerAndi Kleen2006-01-11
| | | | | | | Handling common prefixes is tricky. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] x86_64: don't copy command line twiceJan Beulich2006-01-11
| | | | | | | | | ... reducing the amount of changes Xen has to do. Signed-Off-By: Jan Beulich <jbeulich@novell.com> Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] i386/x86-64: make setup_early_printk() usage consistentJan Beulich2006-01-11
| | | | | | | | | | The explicit and implicit calls to setup_early_printk() were passing inconsistent arguments. Signed-Off-By: Jan Beulich <jbeulich@novell.com> Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] i386: Move DOUBLEFAULT config to arch/i386/KconfigAndi Kleen2006-01-11
| | | | | | | It has no business being elsewhere and x86-64 doesn't need/want it. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] x86_64: Allow kernel page tables upto the end of memoryAndi Kleen2006-01-11
| | | | | | | | | | | Previously they would be only allocated before the kernel text at 1MB. This limited the maximum supported memory to 128GB. Now allow the e820 allocator to put them everywhere. Try to put them beyond any DMA zones to avoid filling them up. This should free some GFP_DMA memory compared to earlier kernels. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] x86_64: Use safe_smp_processor_id in MCE handlerAndi Kleen2006-01-11
| | | | | | | | | | hard_smp_processor_id would return the local APIC id instead of the Linux processor id. On big systems they are often not identical. safe_smp_processor_id is just a wrapper around it that does the necessary conversions. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] x86_64: Some housekeeping in local APIC codeAndi Kleen2006-01-11
| | | | | | | | | | | | | | Remove support for obsolete hardware and cleanup. - Remove checks for non integrated APICs - Replace apic_write_around with apic_write. - Remove apic_read_around - Remove APIC version reads used by old workarounds - Remove old workaround for Simics - Fix indentation Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] x86_64: Display meaningful part of filename during BUG()Jan Beulich2006-01-11
| | | | | | | | | | | | When building in a separate objtree, file names produced by BUG() & Co. can get fairly long; printing only the first 50 characters may thus result in (almost) no useful information. The following change makes it so that rather the last 50 characters of the filename get printed. Signed-Off-By: Jan Beulich <jbeulich@novell.com> Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] x86_64: Reduce screen space needed by stack traceJan Beulich2006-01-11
| | | | | | | | | | | Especially under Xen, where the console cannot be adjusted to more than 25 lines, it is fairly important that the information displayed during a panic is as compact as possible. Below adjustments work towards that. Signed-Off-By: Jan Beulich <jbeulich@novell.com> Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] x86_64: Fix get_cmos_time()Jan Beulich2006-01-11
| | | | | | | | | | | | | Due to a broken condition, the body of the loop that is intended to wait for the Update-In-Progress bit to get set and then cleared again was never entered; in fact, the entire loop was optimized out by the compiler. Here is a change to fix the condition (and to also move the initialization of locals out of the spin lock protected region). Signed-Off-By: Jan Beulich <jbeulich@novell.com> Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] x86_64: No need to export get_cmos_time anymoreAndi Kleen2006-01-11
| | | | | | | | | | | It was only needed for APM Pointed out by Jan Beulich Cc: jbeulich@novell.com Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] x86_64: Remove unused AMD K8 C stepping flagAndi Kleen2006-01-11
| | | | | | | | | X86_FEATURE_K8_C was a synthetic Linux CPUID flag that was used for some code optimizations in Opteron C stepping or later. But support for pre C stepping optimizations has been removed, so this isn't needed anymore. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] i386: Move phys_proc_id/early intel workaround to correct function.Andi Kleen2006-01-11
| | | | | | | | | | early_cpu_detect only runs on the BP, but this code needs to run on all CPUs. Looks like a mismerge somewhere. Also add a warning comment. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] x86_64: sparse warning cleanupsStephen Hemminger2006-01-11
| | | | | | | | Fix some trivial sparse warnings in x86_64 code. Signed-off-by: Stephen Hemminger <shemminger@osdl.org> Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] x86_64: Move NUMA page_to_pfn/pfn_to_page functions out of lineAndi Kleen2006-01-11
| | | | | | | | | | | | Saves about ~18K .text in defconfig There would be more optimization potential, but that's for later. Suggestion originally from Bill Irwin. Fix from Andy Whitcroft. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] x86_64: Remove unused segmentsAndi Kleen2006-01-11
| | | | | | | | | | | They used to be used by the reboot code, but not anymore. Noticed by Jan Beulich Cc: JBeulich@novell.com Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] x86_64: ioapic virtual wire mode fixVivek Goyal2006-01-11
| | | | | | | | | | | | | | | | | | | o Currently, during kexec reboot, IOAPIC is re-programmed back to virtual wire mode if there was an i8259 connected to it. This enables getting timer interrupts in second kernel in legacy mode. o After putting into virtual wire mode, IOAPIC delivers the i8259 interrupts to CPU0. This works well for kexec but not for kdump as we might crash on a different CPU and second kernel will not see timer interrupts. o This patch modifies the redirection table entry to deliver the timer interrupts to the cpu we are rebooting (instead of hardcoding to zero). This ensures that second kernel receives timer interrupts even on a non-boot cpu. Signed-off-by: Vivek Goyal <vgoyal@in.ibm.com> Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] x86_64: Inclusion of ScaleMP vSMP architecture patches - vsmp_archRavikiran G Thirumalai2006-01-11
| | | | | | | | | | | | | | | Introduce vSMP arch to the kernel. This patch: 1. Adds CONFIG_X86_VSMP 2. Adds machine specific macros for local_irq_disabled, local_irq_enabled and irqs_disabled 3. Writes to the vSMP CTL device to indicate kernel compiled with CONFIG_VSMP Signed-off-by: Ravikiran Thirumalai <kiran@scalemp.com> Signed-off-by: Shai Fultheim <shai@scalemp.com> Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] x86_64: Memorize location of i8259 for reboots.Eric W. Biederman2006-01-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently we attempt to restore virtual wire mode on reboot, which only works if we can figure out where the i8259 is connected. This is very useful when we are kexec another kernel and likely helpful to an peculiar BIOS that make assumptions about how the system is setup. Since the acpi MADT table does not provide the location where the i8259 is connected we have to look at the hardware to figure it out. Most systems have the i8259 connected the local apic of the cpu so won't be affected but people running Opteron and some serverworks chipsets should be able to use kexec now. In addition this patch removes the hard coded assumption that the io_apic that delivers isa interrups is always known to the kernel as io_apic 0. There does not appear to be anything to guarantee that assumption is true. And From: Vivek Goyal <vgoyal@in.ibm.com> A minor fix to the patch which remembers the location of where i8259 is connected. Now counter i has been replaced by apic. counter i is having some junk value which was leading to non-detection of i8259 connected to IOAPIC. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Vivek Goyal <vgoyal@in.ibm.com> Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] x86_64: allow setting RF in EFLAGSChuck Ebbert2006-01-11
| | | | | | | | | | Setting RF (resume flag) allows a debugger to resume execution after a code breakpoint without tripping the breakpoint again. It is reset by the CPU after executing one instruction. Signed-off-by: Chuck Ebbert <76306.1226@compuserve.com> Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] x86_64: "invalid operand" -> "invalid opcode"Chuck Ebbert2006-01-11
| | | | | | | | The manual says Int 6 is "invalid opcode", not "invalid operand". Signed-off-by: Chuck Ebbert <76306.1226@compuserve.com> Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] x86_64: Sparse warnings fix.Luiz Fernando Capitulino2006-01-11
| | | | | | | | | | | Fixes the following sparse warnings: arch/x86_64/kernel/mce_amd.c:321:29: warning: Using plain integer as NULL pointer arch/x86_64/kernel/mce_amd.c:410:41: warning: Using plain integer as NULL pointer Signed-off-by: Luiz Capitulino <lcapitulino@mandriva.com.br> Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] x86_64: Remove useless KDB vectorAndi Kleen2006-01-11
| | | | | | | | It was set as an NMI, but the NMI bit always forces an interrupt to end up at vector 2. So it was never used. Remove. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] x86_64: Tell user to enable GART_IOMMU when neededAndi Kleen2006-01-11
| | | | | Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] x86_64: Fix warning in nmi.c on uniprocessor kernelsAndi Kleen2006-01-11
| | | | | | | | | | | | | Fix CC arch/x86_64/kernel/nmi.o linux/arch/x86_64/kernel/nmi.c: In function ???check_nmi_watchdog???: linux/arch/x86_64/kernel/nmi.c:155: warning: statement with no effect on Uniprocessor builds. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] x86_64: Allocate PDAs in the local nodeRavikiran G Thirumalai2006-01-11
| | | | | | | | | | | | Patch uses a static PDA array early at boot and reallocates processor PDA with node local memory when kmalloc is ready, just before pda_init. The boot_cpu_pda is needed since the cpu_pda is used even before pda_init for that cpu is called (to set the static per-cpu areas offset table etc) Signed-off-by: Ravikiran Thirumalai <kiran@scalex86.org> Signed-off-by: Shai Fultheim <shai@scalex86.org> Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] x86_64: Node local pda take 2 -- cpu_pda preparationRavikiran G Thirumalai2006-01-11
| | | | | | | | | | Helper patch to change cpu_pda users to use macros to access cpu_pda instead of the cpu_pda[] array. Signed-off-by: Ravikiran Thirumalai <kiran@scalex86.org> Signed-off-by: Shai Fultheim <shai@scalex86.org> Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] x86_64: Early initialization of cpu_to_nodeRavikiran Thirumalai2006-01-11
| | | | | | | | | | | | | | | | | | | | | | | | Patch enables early intialization of cpu_to_node. apicid_to_node is built by reading the SRAT table, from acpi_numa_init with ACPI_NUMA and k8_scan_nodes with K8_NUMA. x86_cpu_to_apicid is built by parsing the ACPI MADT table, from acpi_boot_init. We combine these two tables and setup cpu_to_node. Early intialization helps the static per_cpu_areas in getting pages from correct node. Change since last release: Do not initialize early init_cpu_to_node for faking node cases. Patch tested on TYAN dual core 4P board with K8 only, ACPI_NUMA. Tested on EM64T NUMA. Also tested with numa=off, numa=fake, and running a kernel compiled with NUMA on a regular EM64 2 way SMP. Signed-off-by: Alok N Kataria <alokk@calsoftinc.com> Signed-off-by: Ravikiran Thirumalai <kiran@scalex86.org> Signed-off-by: Shai Fultheim <shai@scalex86.org> Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] x86_64: Fix up white space in time.cAndi Kleen2006-01-11
| | | | | | | | | No functional changes. And remove one redundant prototype. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] x86_64: Use standard __always_inline in vsyscall.cAndi Kleen2006-01-11
| | | | | | | Replacing the old home brewn __force_inline. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] i386: Replace broken serialize_cpu in microcode driver with correct ↵Andi Kleen2006-01-11
| | | | | | | | | | | | | | | sync_core Passing random input values in eax to cpuid is not a good idea because the CPU will GPF for unknown ones. Use the correct x86-64 version that exists for a longer time too. This also adds a memory barrier to prevent the optimizer from reordering. Cc: tigran@veritas.com Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] x86_64: On Intel CPUs don't do an additional CPU sync before RDTSCAndi Kleen2006-01-11
| | | | | | | | | | | RDTSC serialization using cpuid is not needed for Intel platforms. This increases gettimeofday performance. Cc: vojtech@suse.cz Cc: rohit.seth@intel.com Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] x86_64: Support alternative() in vsyscallsAndi Kleen2006-01-11
| | | | | | | | | The real vsyscall .text addresses are not mapped when the alternative() replacement runs early, so use some black magic to access them using the direct mapping. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] x86_64: Don't try to synchronize the TSC over CPUs on Intel CPUs at ↵Andi Kleen2006-01-11
| | | | | | | | | | | | | boot. They already do this in hardware and the Linux algorithm actually adds errors. Cc: mingo@elte.hu Cc: rohit.seth@intel.com Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] x86_64: x86_64 write apic id fixVivek Goyal2006-01-11
| | | | | | | | | | | | | o Apic id is in most significant 8 bits of APIC_ID register. Current code is trying to write apic id to least significant 8 bits. This patch fixes it. o This fix enables booting uni kdump capture kernel on a cpu with non-zero apic id. Signed-off-by: Vivek Goyal <vgoyal@in.ibm.com> Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] x86_64: Remove duplicate exportsBrian Gerst2006-01-11
| | | | | | | | Remove exports that are already exported from the object's source file. Signed-off-by: Brian Gerst <bgerst@didntduck.org> Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] x86_64: unexport pci_*_consistentBrian Gerst2006-01-11
| | | | | | | | These functions are inlines and shouldn't be exported. Signed-off-by: Brian Gerst <bgerst@didntduck.org> Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] x86_64: Make it clear in machine checks that it's an hardware problemAndi Kleen2006-01-11
| | | | | | | Hopefully the users will take the hint. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] x86_64: Clean up copy_*_userAndi Kleen2006-01-11
| | | | | | | | | | | - Remove optimization for old B stepping Opteron - Make the fast path for copies with a multiple of eight length faster. - Minor instruction rearrangement to hopefully avoid a pipeline stall or two. - Add comment about errata to consider. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] x86_64: Use function pointers to call DMA mapping functionsMuli Ben-Yehuda2006-01-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | AK: I hacked Muli's original patch a lot and there were a lot of changes - all bugs are probably to blame on me now. There were also some changes in the fall back behaviour for swiotlb - in particular it doesn't try to use GFP_DMA now anymore. Also all DMA mapping operations use the same core dma_alloc_coherent code with proper fallbacks now. And various other changes and cleanups. Known problems: iommu=force swiotlb=force together breaks needs more testing. This patch cleans up x86_64's DMA mapping dispatching code. Right now we have three possible IOMMU types: AGP GART, swiotlb and nommu, and in the future we will also have Xen's x86_64 swiotlb and other HW IOMMUs for x86_64. In order to support all of them cleanly, this patch: - introduces a struct dma_mapping_ops with function pointers for each of the DMA mapping operations of gart (AMD HW IOMMU), swiotlb (software IOMMU) and nommu (no IOMMU). - gets rid of: if (swiotlb) return swiotlb_xxx(); - PCI_DMA_BUS_IS_PHYS is now checked against the dma_ops being set This makes swiotlb faster by avoiding double copying in some cases. Signed-Off-By: Muli Ben-Yehuda <mulix@mulix.org> Signed-Off-By: Jon D. Mason <jdmason@us.ibm.com> Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] x86_64: Reject SRAT tables that don't cover all memoryAndi Kleen2006-01-11
| | | | | | | | | | | | Broken BIOS on Iwill 8way systems reports these and it causes the bootmem allocator to crash. Add a sanity check if all the PXMs in the SRAT table cover all memory as reported by e820. If the sanity check fails the SRAT is rejected and the code will fall back to discover the NUMA topology using the K8 northbridge registers when applicable. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] x86_64: Add idle notifiersAndi Kleen2006-01-11
| | | | | | | | | | | | | | | | | | | | | | | | This adds a new notifier chain that is called with IDLE_START when a CPU goes idle and IDLE_END when it goes out of idle. The context can be idle thread or interrupt context. Since we cannot rely on MONITOR/MWAIT existing the idle end check currently has to be done in all interrupt handlers. They were originally inspired by the similar s390 implementation. They have a variety of applications: - They will be needed for CONFIG_NO_IDLE_HZ - They can be used for oprofile to fix up the missing time in idle when performance counters don't tick. - They can be used for better C state management in ACPI - They could be used for microstate accounting. This is just infrastructure so far, no users. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] x86_64: Clean up some printks in NUMA codeAndi Kleen2006-01-11
| | | | | Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] x86_64: Fix up coding style in numa.cAndi Kleen2006-01-11
| | | | | | | No functional changes Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] x86_64: Fix off by one in IOMMU checkAndi Kleen2006-01-11
| | | | | | | | | | | Fix off by one when checking if the machine has enougn memory to need IOMMU This caused the IOMMUs to be needlessly enabled for mem=4G Based on a patch from Jon Mason Signed-off-by: jdmason@us.ibm.com Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] x86_64: Handle missing local APIC timer interrupts on C3 stateVenkatesh Pallipadi2006-01-11
| | | | | | | | | | | | Whenever we see that a CPU is capable of C3 (during ACPI cstate init), we disable local APIC timer and switch to using a broadcast from external timer interrupt (IRQ 0). Patch below adds the code for x86_64. Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] i386: Handle missing local APIC timer interrupts on C3 stateVenkatesh Pallipadi2006-01-11
| | | | | | | | | | | | | Whenever we see that a CPU is capable of C3 (during ACPI cstate init), we disable local APIC timer and switch to using a broadcast from external timer interrupt (IRQ 0). This is needed because Intel CPUs stop the local APIC timer in C3. This is currently only enabled for Intel CPUs. Patch below adds the code for i386 and also the ACPI hunk. Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] i386/x86-64: Remove sub jiffy profile timer supportVenkatesh Pallipadi2006-01-11
| | | | | | | | | | | | | | | | | Remove the finer control of local APIC timer. We cannot provide a sub-jiffy control like this when we use broadcast from external timer in place of local APIC. Instead of removing this only on systems that may end up using broadcast from external timer (due to C3), I am going the "I'm feeling lucky" way to remove this fully. Basically, I am not sure about usefulness of this code today. Few other architectures also don't seem to support this today. If you are using profiling and fine grained control and don't like this going away in normal case, yell at me right now. Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] x86_64: Report hardware breakpoints in user space when triggered by ↵John Blackwood2006-01-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | the kernel I would like to throw out a suggestion for a possible change in the way that the debug register traps are handled in do_debug() when the trap occurs in kernel-mode. In the x86_64 version of do_debug(), the code will skip around sending a SIGTRAP to the current task if the trap occurred while in kernel mode. On the i386-side of things, if the access happens to occur in kernel mode (say during a read(2) of user's buffer that matches the address of a debug register trap), then the do_debug() routine for i386 will go ahead and call send_sigtrap() and send the SIGTRAP signal. The send_sigtrap() code will also set the info.si_addr to NULL in this case (even though I don't understand why, since the SIGTRAP siginfo processing doesn't use the si_addr field...). So I would like to suggest that the x86_64 do_debug() routine also follow this type of behavior and have it go ahead and send the SIGTRAP signal to the current task, even if the debug register trap happens to have occurred in kernel mode. I have taken a stab at a patch for this change below. (It includes the i386-ish change for setting si_addr to NULL when the trap occurred in kernel mode.) It seems like a useful feature to be able to 'watch' a user location that might also be modified in the kernel via a system service call, and have the debugger report that information back to the user, rather than to just silently ignore the trap. Additionally, I realize that users that pull in a kernel debugger such as KGDB into their kernel might want to remove this change below when they add in KGDB support. However, they could alternatively look at the current task's thread.debugreg[] values to see if the trap occurred due to KGDB or instead because of a user-space debugger trap, and still honor the user SIGTRAP processing (instead of the KGDB breakpoint processing) if the trap matches up with the thread.debugreg[] registers. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] x86_64: Convert page fault error codes to symbolic constants.Andi Kleen2006-01-11
| | | | | | | | | | Much better to deal with these than with the magic numbers. And remove the comment describing the bits - kernel source is no replacement for an architecture manual. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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