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https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
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82e844a653
The same getuser/putuser error paths are used regardless of whether AC is set. In non-exception failure cases, this results in an unnecessary CLAC. Fixes the following warnings: arch/x86/lib/getuser.o: warning: objtool: .altinstr_replacement+0x18: redundant UACCESS disable arch/x86/lib/putuser.o: warning: objtool: .altinstr_replacement+0x18: redundant UACCESS disable Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/bc14ded2755ae75bd9010c446079e113dbddb74b.1563413318.git.jpoimboe@redhat.com
106 lines
2 KiB
ArmAsm
106 lines
2 KiB
ArmAsm
/* SPDX-License-Identifier: GPL-2.0 */
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/*
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* __put_user functions.
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*
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* (C) Copyright 2005 Linus Torvalds
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* (C) Copyright 2005 Andi Kleen
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* (C) Copyright 2008 Glauber Costa
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*
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* These functions have a non-standard call interface
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* to make them more efficient, especially as they
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* return an error value in addition to the "real"
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* return value.
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*/
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#include <linux/linkage.h>
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#include <asm/thread_info.h>
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#include <asm/errno.h>
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#include <asm/asm.h>
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#include <asm/smap.h>
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#include <asm/export.h>
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/*
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* __put_user_X
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*
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* Inputs: %eax[:%edx] contains the data
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* %ecx contains the address
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*
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* Outputs: %eax is error code (0 or -EFAULT)
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*
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* These functions should not modify any other registers,
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* as they get called from within inline assembly.
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*/
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#define ENTER mov PER_CPU_VAR(current_task), %_ASM_BX
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.text
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ENTRY(__put_user_1)
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ENTER
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cmp TASK_addr_limit(%_ASM_BX),%_ASM_CX
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jae bad_put_user
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ASM_STAC
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1: movb %al,(%_ASM_CX)
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xor %eax,%eax
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ASM_CLAC
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ret
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ENDPROC(__put_user_1)
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EXPORT_SYMBOL(__put_user_1)
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ENTRY(__put_user_2)
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ENTER
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mov TASK_addr_limit(%_ASM_BX),%_ASM_BX
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sub $1,%_ASM_BX
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cmp %_ASM_BX,%_ASM_CX
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jae bad_put_user
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ASM_STAC
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2: movw %ax,(%_ASM_CX)
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xor %eax,%eax
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ASM_CLAC
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ret
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ENDPROC(__put_user_2)
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EXPORT_SYMBOL(__put_user_2)
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ENTRY(__put_user_4)
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ENTER
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mov TASK_addr_limit(%_ASM_BX),%_ASM_BX
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sub $3,%_ASM_BX
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cmp %_ASM_BX,%_ASM_CX
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jae bad_put_user
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ASM_STAC
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3: movl %eax,(%_ASM_CX)
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xor %eax,%eax
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ASM_CLAC
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ret
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ENDPROC(__put_user_4)
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EXPORT_SYMBOL(__put_user_4)
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ENTRY(__put_user_8)
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ENTER
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mov TASK_addr_limit(%_ASM_BX),%_ASM_BX
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sub $7,%_ASM_BX
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cmp %_ASM_BX,%_ASM_CX
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jae bad_put_user
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ASM_STAC
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4: mov %_ASM_AX,(%_ASM_CX)
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#ifdef CONFIG_X86_32
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5: movl %edx,4(%_ASM_CX)
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#endif
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xor %eax,%eax
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ASM_CLAC
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RET
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ENDPROC(__put_user_8)
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EXPORT_SYMBOL(__put_user_8)
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bad_put_user_clac:
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ASM_CLAC
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bad_put_user:
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movl $-EFAULT,%eax
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RET
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_ASM_EXTABLE_UA(1b, bad_put_user_clac)
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_ASM_EXTABLE_UA(2b, bad_put_user_clac)
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_ASM_EXTABLE_UA(3b, bad_put_user_clac)
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_ASM_EXTABLE_UA(4b, bad_put_user_clac)
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#ifdef CONFIG_X86_32
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_ASM_EXTABLE_UA(5b, bad_put_user_clac)
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#endif
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