kernel.git/arch/x86/lib, branch linux-3.18.y

x86/boot: Fix early command-line parsing when matching at end

2018-07-11T13:42:24Z

commit 02afeaae9843733a39cd9b11053748b2d1dc5ae7 upstream. The x86 early command line parsing in cmdline_find_option_bool() is buggy. If it matches a specified 'option' all the way to the end of the command-line, it will consider it a match. For instance, cmdline = "foo"; cmdline_find_option_bool(cmdline, "fool"); will return 1. This is particularly annoying since we have actual FPU options like "noxsave" and "noxsaves" So, command-line "foo bar noxsave" will match *BOTH* a "noxsave" and "noxsaves". (This turns out not to be an actual problem because "noxsave" implies "noxsaves", but it's still confusing.) To fix this, we simplify the code and stop tracking 'len'. 'len' was trying to indicate either the NULL terminator *OR* the end of a non-NULL-terminated command line at 'COMMAND_LINE_SIZE'. But, each of the three states is *already* checking 'cmdline' for a NULL terminator. We _only_ need to check if we have overrun 'COMMAND_LINE_SIZE', and that we can do without keeping 'len' around. Also add some commends to clarify what is going on. Signed-off-by: Dave Hansen Signed-off-by: Borislav Petkov Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Brian Gerst Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: fenghua.yu@intel.com Cc: yu-cheng.yu@intel.com Link: http://lkml.kernel.org/r/20151222225238.9AEB560C@viggo.jf.intel.com Signed-off-by: Ingo Molnar Cc: Ben Hutchings Signed-off-by: Greg Kroah-Hartman

x86/decoder: Add new TEST instruction pattern

2017-11-30T08:35:49Z

commit 12a78d43de767eaf8fb272facb7a7b6f2dc6a9df upstream. The kbuild test robot reported this build warning: Warning: arch/x86/tools/test_get_len found difference at :ffffffff8103dd2c Warning: ffffffff8103dd82: f6 09 d8 testb $0xd8,(%rcx) Warning: objdump says 3 bytes, but insn_get_length() says 2 Warning: decoded and checked 1569014 instructions with 1 warnings This sequence seems to be a new instruction not in the opcode map in the Intel SDM. The instruction sequence is "F6 09 d8", means Group3(F6), MOD(00)REG(001)RM(001), and 0xd8. Intel SDM vol2 A.4 Table A-6 said the table index in the group is "Encoding of Bits 5,4,3 of the ModR/M Byte (bits 2,1,0 in parenthesis)" In that table, opcodes listed by the index REG bits as: 000 001 010 011 100 101 110 111 TEST Ib/Iz,(undefined),NOT,NEG,MUL AL/rAX,IMUL AL/rAX,DIV AL/rAX,IDIV AL/rAX So, it seems TEST Ib is assigned to 001. Add the new pattern. Reported-by: kbuild test robot Signed-off-by: Masami Hiramatsu Cc: Greg Kroah-Hartman Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman

x86-64: make csum_partial_copy_from_user() error handling consistent

2014-11-16T19:00:42Z

Al Viro pointed out that the x86-64 csum_partial_copy_from_user() is somewhat confused about what it should do on errors, notably it mostly clears the uncopied end result buffer, but misses that for the initial alignment case. All users should check for errors, so it's dubious whether the clearing is even necessary, and Al also points out that we should probably clean up the calling conventions, but regardless of any future changes to this function, the fact that it is inconsistent is just annoying. So make the __get_user() failure path use the same error exit as all the other errors do. Reported-by: Al Viro Cc: David Miller Cc: Andi Kleen Signed-off-by: Linus Torvalds

Merge branch 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2014-10-13T16:14:50Z

Pull x86 asm updates from Ingo Molnar: "The changes in this cycle were: - Speed up the x86 __preempt_schedule() implementation - Fix/improve low level asm code debug info annotations" * 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86: Unwind-annotate thunk_32.S x86: Improve cmpxchg8b_emu.S x86: Improve cmpxchg16b_emu.S x86/lib/Makefile: Remove the unnecessary "+= thunk_64.o" x86: Speed up ___preempt_schedule*() by using THUNK helpers

x86: Unwind-annotate thunk_32.S

2014-10-08T10:31:45Z

Signed-off-by: Jan Beulich Link: http://lkml.kernel.org/r/542291CA0200007800038085@mail.emea.novell.com Signed-off-by: Thomas Gleixner

x86: Improve cmpxchg8b_emu.S

2014-10-08T08:05:49Z

- don't include unneeded headers - drop redundant entry point label - complete unwind annotations - use .L prefix on local labels to not clutter the symbol table Signed-off-by: Jan Beulich Link: http://lkml.kernel.org/r/5422917E0200007800038081@mail.emea.novell.com Signed-off-by: Thomas Gleixner

x86: Improve cmpxchg16b_emu.S

2014-10-08T08:05:49Z

- don't include unneeded headers - don't open-code PER_CPU_VAR() - drop redundant entry point label - complete unwind annotations - use .L prefix on local label to not clutter the symbol table Signed-off-by: Jan Beulich Link: http://lkml.kernel.org/r/542290BC020000780003807D@mail.emea.novell.com Signed-off-by: Thomas Gleixner

x86/lib/Makefile: Remove the unnecessary "+= thunk_64.o"

2014-09-24T13:15:39Z

Trivial. We have "lib-y += thunk_$(BITS).o" at the start, no need to add thunk_64.o if !CONFIG_X86_32. Signed-off-by: Oleg Nesterov Acked-by: Andy Lutomirski Cc: Denys Vlasenko Cc: Peter Zijlstra Cc: Linus Torvalds Link: http://lkml.kernel.org/r/20140921184232.GB23727@redhat.com Signed-off-by: Ingo Molnar

x86: Speed up ___preempt_schedule*() by using THUNK helpers

2014-09-24T13:15:38Z

___preempt_schedule() does SAVE_ALL/RESTORE_ALL but this is suboptimal, we do not need to save/restore the callee-saved register. And we already have arch/x86/lib/thunk_*.S which implements the similar asm wrappers, so it makes sense to redefine ___preempt_schedule() as "THUNK ..." and remove preempt.S altogether. Signed-off-by: Oleg Nesterov Reviewed-by: Andy Lutomirski Cc: Denys Vlasenko Cc: Peter Zijlstra Cc: Linus Torvalds Link: http://lkml.kernel.org/r/20140921184153.GA23727@redhat.com Signed-off-by: Ingo Molnar

locking/rwlock, x86: Delete unused asm/rwlock.h and rwlock.S

2014-09-10T09:46:39Z

This patch removes the unused asm/rwlock.h and rwlock.S files. Signed-off-by: Waiman Long Signed-off-by: Peter Zijlstra (Intel) Link: http://lkml.kernel.org/r/1408037251-45918-3-git-send-email-Waiman.Long@hp.com Cc: Scott J Norton Cc: Borislav Petkov Cc: Daniel Borkmann Cc: David S. Miller Cc: Francesco Fusco Cc: Linus Torvalds Cc: Thomas Graf Signed-off-by: Ingo Molnar