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2012-03-09x86: Use enum instead of literals for trap valuesKees Cook1-0/+25
The traps are referred to by their numbers and it can be difficult to understand them while reading the code without context. This patch adds enumeration of the trap numbers and replaces the numbers with the correct enum for x86. Signed-off-by: Kees Cook <keescook@chromium.org> Link: http://lkml.kernel.org/r/20120310000710.GA32667@www.outflux.net Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2011-08-10x86-64: Rework vsyscall emulation and add vsyscall= parameterAndy Lutomirski1-2/+0
There are three choices: vsyscall=native: Vsyscalls are native code that issues the corresponding syscalls. vsyscall=emulate (default): Vsyscalls are emulated by instruction fault traps, tested in the bad_area path. The actual contents of the vsyscall page is the same as the vsyscall=native case except that it's marked NX. This way programs that make assumptions about what the code in the page does will not be confused when they read that code. vsyscall=none: Trying to execute a vsyscall will segfault. Signed-off-by: Andy Lutomirski <luto@mit.edu> Link: http://lkml.kernel.org/r/8449fb3abf89851fd6b2260972666a6f82542284.1312988155.git.luto@mit.edu Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2011-06-07x86-64: Emulate legacy vsyscallsAndy Lutomirski1-0/+4
There's a fair amount of code in the vsyscall page. It contains a syscall instruction (in the gettimeofday fallback) and who knows what will happen if an exploit jumps into the middle of some other code. Reduce the risk by replacing the vsyscalls with short magic incantations that cause the kernel to emulate the real vsyscalls. These incantations are useless if entered in the middle. This causes vsyscalls to be a little more expensive than real syscalls. Fortunately sensible programs don't use them. The only exception is time() which is still called by glibc through the vsyscall - but calling time() millions of times per second is not sensible. glibc has this fixed in the development tree. This patch is not perfect: the vread_tsc and vread_hpet functions are still at a fixed address. Fixing that might involve making alternative patching work in the vDSO. Signed-off-by: Andy Lutomirski <luto@mit.edu> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Jesper Juhl <jj@chaosbits.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Arjan van de Ven <arjan@infradead.org> Cc: Jan Beulich <JBeulich@novell.com> Cc: richard -rw- weinberger <richard.weinberger@gmail.com> Cc: Mikael Pettersson <mikpe@it.uu.se> Cc: Andi Kleen <andi@firstfloor.org> Cc: Brian Gerst <brgerst@gmail.com> Cc: Louis Rilling <Louis.Rilling@kerlabs.com> Cc: Valdis.Kletnieks@vt.edu Cc: pageexec@freemail.hu Link: http://lkml.kernel.org/r/e64e1b3c64858820d12c48fa739efbd1485e79d5.1307292171.git.luto@mit.edu [ Removed the CONFIG option - it's simpler to just do it unconditionally. Tidied up the code as well. ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-01-12KVM: Handle async PF in a guest.Gleb Natapov1-0/+1
When async PF capability is detected hook up special page fault handler that will handle async page fault events and bypass other page faults to regular page fault handler. Also add async PF handling to nested SVM emulation. Async PF always generates exit to L1 where vcpu thread will be scheduled out until page is available. Acked-by: Rik van Riel <riel@redhat.com> Signed-off-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-05-03x86: Merge simd_math_error() into math_error()Brian Gerst1-1/+1
The only difference between FPU and SIMD exceptions is where the status bits are read from (cwd/swd vs. mxcsr). This also fixes the discrepency introduced by commit adf77bac, which fixed FPU but not SIMD. Signed-off-by: Brian Gerst <brgerst@gmail.com> LKML-Reference: <1269176446-2489-3-git-send-email-brgerst@gmail.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-07-19x86: Remove unused patch_espfix_desc()Akinobu Mita1-3/+1
patch_espfix_desc() is not used after commit dc4c2a0aed3b09f6e255bd5c3faa50fe6e0b2ded Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> LKML-Reference: <20090718150955.GB11294@localhost.localdomain> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-06-10Merge branch 'x86-xen-for-linus' of ↵Linus Torvalds1-0/+3
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'x86-xen-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (42 commits) xen: cache cr0 value to avoid trap'n'emulate for read_cr0 xen/x86-64: clean up warnings about IST-using traps xen/x86-64: fix breakpoints and hardware watchpoints xen: reserve Xen start_info rather than e820 reserving xen: add FIX_TEXT_POKE to fixmap lguest: update lazy mmu changes to match lguest's use of kvm hypercalls xen: honour VCPU availability on boot xen: add "capabilities" file xen: drop kexec bits from /sys/hypervisor since kexec isn't implemented yet xen/sys/hypervisor: change writable_pt to features xen: add /sys/hypervisor support xen/xenbus: export xenbus_dev_changed xen: use device model for suspending xenbus devices xen: remove suspend_cancel hook xen/dev-evtchn: clean up locking in evtchn xen: export ioctl headers to userspace xen: add /dev/xen/evtchn driver xen: add irq_from_evtchn xen: clean up gate trap/interrupt constants xen: set _PAGE_NX in __supported_pte_mask before pagetable construction ...
2009-06-10Merge branch 'x86-mm-for-linus' of ↵Linus Torvalds1-0/+1
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (22 commits) x86: fix system without memory on node0 x86, mm: Fix node_possible_map logic mm, x86: remove MEMORY_HOTPLUG_RESERVE related code x86: make sparse mem work in non-NUMA mode x86: process.c, remove useless headers x86: merge process.c a bit x86: use sparse_memory_present_with_active_regions() on UMA x86: unify 64-bit UMA and NUMA paging_init() x86: Allow 1MB of slack between the e820 map and SRAT, not 4GB x86: Sanity check the e820 against the SRAT table using e820 map only x86: clean up and and print out initial max_pfn_mapped x86/pci: remove rounding quirk from e820_setup_gap() x86, e820, pci: reserve extra free space near end of RAM x86: fix typo in address space documentation x86: 46 bit physical address support on 64 bits x86, mm: fault.c, use printk_once() in is_errata93() x86: move per-cpu mmu_gathers to mm/init.c x86: move max_pfn_mapped and max_low_pfn_mapped to setup.c x86: unify noexec handling x86: remove (null) in /sys kernel_page_tables ...
2009-05-08xen/x86-64: fix breakpoints and hardware watchpointsJeremy Fitzhardinge1-0/+3
Native x86-64 uses the IST mechanism to run int3 and debug traps on an alternative stack. Xen does not do this, and so the frames were being misinterpreted by the ptrace code. This change special-cases these two exceptions by using Xen variants which run on the normal kernel stack properly. Impact: avoid crash or bad data when IST trap is invoked under Xen Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
2009-04-14x86: avoid multiple declaration of kstack_depth_to_printJaswinder Singh Rajput1-1/+0
Impact: cleanup asm/stacktrace.h is more appropriate so removing other 2 declarations. Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com> Cc: Neil Horman <nhorman@tuxdriver.com> LKML-Reference: <1239695308.3033.34.camel@ht.satnam> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-30x86/mm: further cleanups of fault.c's include file sectionIngo Molnar1-0/+1
Impact: cleanup Eliminate more than 20 unnecessary #include lines in fault.c Also fix include file dependency bug in asm/traps.h. (this was masked before, by implicit inclusion) Signed-off-by: Ingo Molnar <mingo@elte.hu> LKML-Reference: <tip-56aea8468746e673a4bf50b6a13d97b2d1cbe1e8@git.kernel.org> Acked-by: H. Peter Anvin <hpa@linux.intel.com>
2009-02-11x86: use pt_regs pointer in do_device_not_available()Brian Gerst1-1/+1
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>
2009-02-10x86: fix math_emu register frame accessTejun Heo1-2/+2
do_device_not_available() is the handler for #NM and it declares that it takes a unsigned long and calls math_emu(), which takes a long argument and surprisingly expects the stack frame starting at the zero argument would match struct math_emu_info, which isn't true regardless of configuration in the current code. This patch makes do_device_not_available() take struct pt_regs like other exception handlers and initialize struct math_emu_info with pointer to it and pass pointer to the math_emu_info to math_emulate() like normal C functions do. This way, unless gcc makes a copy of struct pt_regs in do_device_not_available(), the register frame is correctly accessed regardless of kernel configuration or compiler used. This doesn't fix all math_emu problems but it at least gets it somewhat working. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-18x86: traps.c declare functions before they get usedJaswinder Singh1-2/+9
Impact: cleanup In asm/traps.h :- do_double_fault : added under X86_64 sync_regs : added under X86_64 math_error : moved out from X86_32 as it is common for both 32 and 64 bit math_emulate : moved from X86_32 as it is common for both 32 and 64 bit smp_thermal_interrupt : added under X86_64 mce_threshold_interrupt : added under X86_64 Signed-off-by: Jaswinder Singh <jaswinder@infradead.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-22x86: Fix ASM_X86__ header guardsH. Peter Anvin1-3/+3
Change header guards named "ASM_X86__*" to "_ASM_X86_*" since: a. the double underscore is ugly and pointless. b. no leading underscore violates namespace constraints. Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2008-10-22x86, um: ... and asm-x86 moveAl Viro1-0/+81
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: H. Peter Anvin <hpa@zytor.com>