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2009-06-20x86, 64-bit: Clean up user address maskingLinus Torvalds1-1/+1
The discussion about using "access_ok()" in get_user_pages_fast() (see commit 7f8189068726492950bf1a2dcfd9b51314560abf: "x86: don't use 'access_ok()' as a range check in get_user_pages_fast()" for details and end result), made us notice that x86-64 was really being very sloppy about virtual address checking. So be way more careful and straightforward about masking x86-64 virtual addresses: - All the VIRTUAL_MASK* variants now cover half of the address space, it's not like we can use the full mask on a signed integer, and the larger mask just invites mistakes when applying it to either half of the 48-bit address space. - /proc/kcore's kc_offset_to_vaddr() becomes a lot more obvious when it transforms a file offset into a (kernel-half) virtual address. - Unify/simplify the 32-bit and 64-bit USER_DS definition to be based on TASK_SIZE_MAX. This cleanup and more careful/obvious user virtual address checking also uncovered a buglet in the x86-64 implementation of strnlen_user(): it would do an "access_ok()" check on the whole potential area, even if the string itself was much shorter, and thus return an error even for valid strings. Our sloppy checking had hidden this. So this fixes 'strnlen_user()' to do this properly, the same way we already handled user strings in 'strncpy_from_user()'. Namely by just checking the first byte, and then relying on fault handling for the rest. That always works, since we impose a guard page that cannot be mapped at the end of the user space address space (and even if we didn't, we'd have the address space hole). Acked-by: Ingo Molnar <mingo@elte.hu> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Nick Piggin <npiggin@suse.de> Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-10x86: MSR: add methods for writing of an MSR on several CPUsBorislav Petkov1-6/+92
Provide for concurrent MSR writes on all the CPUs in the cpumask. Also, add a temporary workaround for smp_call_function_many which skips the CPU we're executing on. Bart: zero out rv struct which is allocated on stack. CC: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Borislav Petkov <borislav.petkov@amd.com> Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
2009-06-10x86: MSR: add a struct representation of an MSRBorislav Petkov2-14/+14
Add a struct representing a 64bit MSR pair consisting of a low and high register part and convert msr_info to use it. Also, rename msr-on-cpu.c to msr.c. Side note: Put the cpumask.h include in __KERNEL__ space thus fixing an allmodconfig build failure in the headers_check target. CC: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
2009-03-12x86: memcpy, clean upIngo Molnar1-55/+81
Impact: cleanup Make this file more readable by bringing it more in line with the usual kernel style. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-12x86-64: remove unnecessary spill/reload of rbx from memcpyJan Beulich1-7/+0
Impact: micro-optimization This should slightly improve its performance. Signed-off-by: Jan Beulich <jbeulich@novell.com> LKML-Reference: <49B8F641.76E4.0078.0@novell.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-13x86: use _types.h headers in asm where availableJeremy Fitzhardinge1-1/+1
In general, the only definitions that assembly files can use are in _types.S headers (where available), so convert them. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
2009-01-21x86: use early clobbers in usercopy*.cAndi Kleen2-4/+4
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>
2008-10-28Merge commit 'v2.6.28-rc2' into core/lockingIngo Molnar5-69/+67
Conflicts: arch/um/include/asm/system.h
2008-10-11Merge branch 'x86/unify-cpu-detect' into x86-v28-for-linus-phase4-DIngo Molnar2-3/+7
Conflicts: arch/x86/kernel/cpu/common.c arch/x86/kernel/signal_64.c include/asm-x86/cpufeature.h
2008-09-11x86: some lock annotations for user copy paths, v3Ingo Molnar1-0/+1
- add annotation back to clear_user() - change probe_kernel_address() to _inatomic*() method Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-11x86: some lock annotations for user copy paths, v2Nick Piggin2-15/+5
- introduce might_fault() - handle the atomic user copy paths correctly [ mingo@elte.hu: move might_sleep() outside of in_atomic(). ] Signed-off-by: Nick Piggin <npiggin@suse.de> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-10x86: some lock annotations for user copy pathsNick Piggin2-1/+10
copy_to/from_user and all its variants (except the atomic ones) can take a page fault and perform non-trivial work like taking mmap_sem and entering the filesyste/pagecache. Unfortunately, this often escapes lockdep because a common pattern is to use it to read in some arguments just set up from userspace, or write data back to a hot buffer. In those cases, it will be unlikely for page reclaim to get a window in to cause copy_*_user to fault. With the new might_lock primitives, add some annotations to x86. I don't know if I caught all possible faulting points (it's a bit of a maze, and I didn't really look at 32-bit). But this is a starting point. Boots and runs OK so far. Signed-off-by: Nick Piggin <npiggin@suse.de> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-04x86: drop -funroll-loops for csum_partial_64.cAndi Kleen1-3/+0
Impact: performance optimization I did some rebenchmarking with modern compilers and dropping -funroll-loops makes the function consistently go faster by a few percent. So drop that flag. Thanks to Richard Guenther for a hint. Signed-off-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2008-08-27Merge branch 'x86/urgent' into x86/cpuH. Peter Anvin1-10/+12
Conflicts: arch/x86/kernel/cpu/cyrix.c
2008-08-25x86: msr-on-cpu: remove unnecessary level of abstractionH. Peter Anvin1-42/+36
Remove an unnecessary level of abstraction in the msr-on-cpu library. Although this duplicates some code, the duplicated code is less than the additional code, and this way should be faster. Additionally, change the order of the functions to make the regular structure of this file more obvious. Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2008-08-25Merge branch 'x86/urgent' into x86/cleanupsH. Peter Anvin1-10/+12
2008-08-25x86: msr: propagate errors from smp_call_function_single()H. Peter Anvin1-10/+12
Propagate error (-ENXIO) from smp_call_function_single(). These errors can happen when a CPU is unplugged while the MSR driver is open. Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2008-08-18x86: make movsl_mask definition non-CPU specificThomas Petazzoni1-0/+7
movsl_mask is currently defined in arch/x86/kernel/cpu/intel.c, which contains code specific to Intel CPUs. However, movsl_mask is used in the non-CPU specific code in arch/x86/lib/usercopy_32.c, which breaks the compilation when support for Intel CPUs is compiled out. This patch solves this problem by moving movsl_mask's definition close to its users in arch/x86/lib/usercopy_32.c. Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com> Cc: michael@free-electrons.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-15x86: coding style fixes to arch/x86/lib/string_32.cPaolo Ciarrocchi1-21/+21
Before: total: 21 errors, 0 warnings, 237 lines checked After: total: 0 errors, 0 warnings, 237 lines checked paolo@paolo-desktop:~/linux.trees.git$ md5sum /tmp/string_32.o.* c55d059ef1612b32a8bb2771a72ae0d5 /tmp/string_32.o.after c55d059ef1612b32a8bb2771a72ae0d5 /tmp/string_32.o.before Signed-off-by: Paolo Ciarrocchi <paolo.ciarrocchi@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-15x86: coding style fixes to arch/x86/lib/strstr_32.cPaolo Ciarrocchi1-3/+3
Before: total: 3 errors, 0 warnings, 31 lines checked After: total: 0 errors, 0 warnings, 31 lines checked paolo@paolo-desktop:~/linux.trees.git$ md5sum /tmp/strstr_32.o.* c96006ec3387862e5bacb139207a3098 /tmp/strstr_32.o.after c96006ec3387862e5bacb139207a3098 /tmp/strstr_32.o.before Signed-off-by: Paolo Ciarrocchi <paolo.ciarrocchi@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-30x86: wrong register was used in align macroVitaly Mayatskikh2-3/+2
New ALIGN_DESTINATION macro has sad typo: r8d register was used instead of ecx in fixup section. This can be considered as a regression. Register ecx was also wrongly loaded with value in r8d in copy_user_nocache routine. Signed-off-by: Vitaly Mayatskikh <v.mayatskih@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-15Merge branch 'generic-ipi' into generic-ipi-for-linusIngo Molnar1-4/+4
Conflicts: arch/powerpc/Kconfig arch/s390/kernel/time.c arch/x86/kernel/apic_32.c arch/x86/kernel/cpu/perfctr-watchdog.c arch/x86/kernel/i8259_64.c arch/x86/kernel/ldt.c arch/x86/kernel/nmi_64.c arch/x86/kernel/smpboot.c arch/x86/xen/smp.c include/asm-x86/hw_irq_32.h include/asm-x86/hw_irq_64.h include/asm-x86/mach-default/irq_vectors.h include/asm-x86/mach-voyager/irq_vectors.h include/asm-x86/smp.h kernel/Makefile Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-14Merge branch 'auto-ftrace-next' into tracing/for-linusIngo Molnar3-2/+65
Conflicts: arch/x86/kernel/entry_32.S arch/x86/kernel/process_32.c arch/x86/kernel/process_64.c arch/x86/lib/Makefile include/asm-x86/irqflags.h kernel/Makefile kernel/sched.c Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-10x86: fix compile error in current tip.gitJeremy Fitzhardinge2-3/+3
Gas 2.15 complains about 32-bit registers being used in lea. AS arch/x86/lib/copy_user_64.o /local/scratch-2/jeremy/hg/xen/paravirt/linux/arch/x86/lib/copy_user_64.S: Assembler messages: /local/scratch-2/jeremy/hg/xen/paravirt/linux/arch/x86/lib/copy_user_64.S:188: Error: `(%edx,%ecx,8)' is not a valid 64 bit base/index expression /local/scratch-2/jeremy/hg/xen/paravirt/linux/arch/x86/lib/copy_user_64.S:257: Error: `(%edx,%ecx,8)' is not a valid 64 bit base/index expression AS arch/x86/lib/copy_user_nocache_64.o /local/scratch-2/jeremy/hg/xen/paravirt/linux/arch/x86/lib/copy_user_nocache_64.S: Assembler messages: /local/scratch-2/jeremy/hg/xen/paravirt/linux/arch/x86/lib/copy_user_nocache_64.S:107: Error: `(%edx,%ecx,8)' is not a valid 64 bit base/index expression Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Cc: Vitaly Mayatskikh <v.mayatskih@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-09x86: fix copy_user on x86Vitaly Mayatskikh2-435/+275
Switch copy_user_generic_string(), copy_user_generic_unrolled() and __copy_user_nocache() from custom tail handlers to generic copy_user_tail_handle(). Signed-off-by: Vitaly Mayatskikh <v.mayatskih@gmail.com> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-09x86: introduce copy_user_handle_tail() routineVitaly Mayatskikh1-0/+23
Introduce generic C routine for handling necessary tail operations after protection fault in copy_*_user on x86. Signed-off-by: Vitaly Mayatskikh <v.mayatskih@gmail.com> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-09x86: merge putuser asm functions.Glauber Costa3-97/+10
putuser_32.S and putuser_64.S are merged into putuser.S. Signed-off-by: Glauber Costa <gcosta@redhat.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-09x86: use macros from asm.h.Glauber Costa2-41/+43
In putuser_32.S and putuser_64.S, replace things like .quad, .long, and explicit references to [r|e]ax for the apropriate macros in asm/asm.h. Signed-off-by: Glauber Costa <gcosta@redhat.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-09x86: don't use word-size specifiers in putuser files.Glauber Costa2-21/+21
Remove them where unambiguous. Signed-off-by: Glauber Costa <gcosta@redhat.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-09x86: replace function headers by macros.Glauber Costa1-18/+14
In putuser_64.S, do it the i386 way, and replace the code in beginning and end of functions with macros, since it's always the same thing. Save lines. Signed-off-by: Glauber Costa <gcosta@redhat.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-09x86: change testing logic in putuser_64.S.Glauber Costa1-21/+12
Instead of operating over a register we need to put back into normal state afterwards (the memory position), just sub from rbx, which is trashed anyway. We can save a few instructions. Also, this is the i386 way. Signed-off-by: Glauber Costa <gcosta@redhat.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-09x86: pass argument to putuser_64 functions in ax register.Glauber Costa1-4/+4
This is consistent with i386 usage. Signed-off-by: Glauber Costa <gcosta@redhat.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-09x86: clobber rbx in putuser_64.S.Glauber Costa1-9/+9
Instead of clobbering r8, clobber rbx, which is the i386 way. Signed-off-by: Glauber Costa <gcosta@redhat.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-09x86: don't save ebx in putuser_32.S.Glauber Costa1-11/+2
Clobber it in the inline asm macros, and let the compiler do this for us. Signed-off-by: Glauber Costa <gcosta@redhat.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-09x86: merge getuser asm functions.Glauber Costa3-85/+10
getuser_32.S and getuser_64.S are merged into getuser.S. Signed-off-by: Glauber Costa <gcosta@redhat.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-09x86: use _ASM_PTR instead of explicit word-size pointers.Glauber Costa2-7/+7
Switch .long and .quad with _ASM_PTR in getuser*.S. Signed-off-by: Glauber Costa <gcosta@redhat.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-09x86: introduce __ASM_REG macro.Glauber Costa2-30/+31
There are situations in which the architecture wants to use the register that represents its word-size, whatever it is. For those, introduce __ASM_REG in asm.h, along with the first users _ASM_AX and _ASM_DX. They have users waiting for it, namely the getuser functions. Signed-off-by: Glauber Costa <gcosta@redhat.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-09x86: don't use word-size specifiers on getuser_64.Glauber Costa1-14/+14
The instructions access registers, so the size is unambiguous. Signed-off-by: Glauber Costa <gcosta@redhat.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-09x86: rename threadinfo to TI.Glauber Costa3-10/+10
This is for consistency with i386. Signed-off-by: Glauber Costa <gcosta@redhat.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-09x86: adapt x86_64 getuser functions.Glauber Costa1-21/+12
Instead of doing a sub after the addition, use the offset directly at the memory operand of the mov instructions. This is the way i386 do. Signed-off-by: Glauber Costa <gcosta@redhat.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-09x86: don't use word-size specifiers.Glauber Costa1-12/+12
Since the instructions refer to registers, they'll be able to figure it out. Signed-off-by: Glauber Costa <gcosta@redhat.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-09x86: don't clobber r8 nor use rcx.Glauber Costa1-21/+21
There's really no reason to clobber r8 or pass the address in rcx. We can safely use only two registers (which we already have to touch anyway) to do the job. Signed-off-by: Glauber Costa <gcosta@redhat.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-09x86: integrate delay functions.Glauber Costa3-135/+6
delay_32.c, delay_64.c are now equal, and are integrated into delay.c. Signed-off-by: Glauber Costa <gcosta@redhat.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-09x86: explicitly use edx in const delay function.Glauber Costa2-3/+10
For x86_64, we can't just use %0, as it would generate a mul against rdx, which is not really what we want (note the ">> 32" in x86_64 version). Using a u64 variable with a shift in i386 generates bad code, so the solution is to explicitly use %%edx in inline assembly for both. Signed-off-by: Glauber Costa <gcosta@redhat.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-09x86: use rdtscll in read_current_timer for i386.Glauber Costa1-1/+1
This way we achieve the same code for both arches. Signed-off-by: Glauber Costa <gcosta@redhat.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-09x86: provide delay loop for x86_64.Glauber Costa1-4/+40
This is for consistency with i386. We call use_tsc_delay() at tsc initialization for x86_64, so we'll be always using it. Signed-off-by: Glauber Costa <gcosta@redhat.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-09x86: don't use size specifiers.Glauber Costa1-2/+2
Remove the "l" from inline asm at arch/x86/lib/delay_32.c. It is not needed. Signed-off-by: Glauber Costa <gcosta@redhat.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-26smp_call_function: get rid of the unused nonatomic/retry argumentJens Axboe1-4/+4
It's never used and the comments refer to nonatomic and retry interchangably. So get rid of it. Acked-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-06-25Merge branch 'linus' into x86/delayIngo Molnar2-28/+22
Conflicts: arch/x86/kernel/tsc_32.c Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-23Merge branch 'linus' into tracing/ftraceIngo Molnar2-28/+22
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