Messages in this thread Patch in this message | | | Date | Sun, 17 Mar 2019 00:02:39 +0300 | From | Alexey Dobriyan <> | Subject | [PATCH 2/4] x86, putuser: copy pasta into 32 and 64-bit versions |
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I'm going to rewrite 64-bit version to use normal x86_64 calling convention.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> ---
arch/x86/lib/Makefile | 3 - arch/x86/lib/putuser_64.S | 103 ++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 105 insertions(+), 1 deletion(-)
--- a/arch/x86/lib/Makefile +++ b/arch/x86/lib/Makefile @@ -21,7 +21,8 @@ clean-files := inat-tables.c obj-$(CONFIG_SMP) += msr-smp.o cache-smp.o lib-y := delay.o misc.o cmdline.o cpu.o -lib-y += usercopy_$(BITS).o usercopy.o getuser.o putuser.o +lib-y += usercopy_$(BITS).o usercopy.o getuser.o +lib-y += putuser_$(BITS).o lib-y += memcpy_$(BITS).o lib-$(CONFIG_RWSEM_XCHGADD_ALGORITHM) += rwsem.o lib-$(CONFIG_INSTRUCTION_DECODER) += insn.o inat.o insn-eval.o similarity index 100% rename from arch/x86/lib/putuser.S rename to arch/x86/lib/putuser_32.S new file mode 100644 --- /dev/null +++ b/arch/x86/lib/putuser_64.S @@ -0,0 +1,103 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * __put_user functions. + * + * (C) Copyright 2005 Linus Torvalds + * (C) Copyright 2005 Andi Kleen + * (C) Copyright 2008 Glauber Costa + * + * These functions have a non-standard call interface + * to make them more efficient, especially as they + * return an error value in addition to the "real" + * return value. + */ +#include <linux/linkage.h> +#include <asm/thread_info.h> +#include <asm/errno.h> +#include <asm/asm.h> +#include <asm/smap.h> +#include <asm/export.h> + + +/* + * __put_user_X + * + * Inputs: %eax[:%edx] contains the data + * %ecx contains the address + * + * Outputs: %eax is error code (0 or -EFAULT) + * + * These functions should not modify any other registers, + * as they get called from within inline assembly. + */ + +#define ENTER mov PER_CPU_VAR(current_task), %_ASM_BX +#define EXIT ASM_CLAC ; \ + ret + +.text +ENTRY(__put_user_1) + ENTER + cmp TASK_addr_limit(%_ASM_BX),%_ASM_CX + jae bad_put_user + ASM_STAC +1: movb %al,(%_ASM_CX) + xor %eax,%eax + EXIT +ENDPROC(__put_user_1) +EXPORT_SYMBOL(__put_user_1) + +ENTRY(__put_user_2) + ENTER + mov TASK_addr_limit(%_ASM_BX),%_ASM_BX + sub $1,%_ASM_BX + cmp %_ASM_BX,%_ASM_CX + jae bad_put_user + ASM_STAC +2: movw %ax,(%_ASM_CX) + xor %eax,%eax + EXIT +ENDPROC(__put_user_2) +EXPORT_SYMBOL(__put_user_2) + +ENTRY(__put_user_4) + ENTER + mov TASK_addr_limit(%_ASM_BX),%_ASM_BX + sub $3,%_ASM_BX + cmp %_ASM_BX,%_ASM_CX + jae bad_put_user + ASM_STAC +3: movl %eax,(%_ASM_CX) + xor %eax,%eax + EXIT +ENDPROC(__put_user_4) +EXPORT_SYMBOL(__put_user_4) + +ENTRY(__put_user_8) + ENTER + mov TASK_addr_limit(%_ASM_BX),%_ASM_BX + sub $7,%_ASM_BX + cmp %_ASM_BX,%_ASM_CX + jae bad_put_user + ASM_STAC +4: mov %_ASM_AX,(%_ASM_CX) +#ifdef CONFIG_X86_32 +5: movl %edx,4(%_ASM_CX) +#endif + xor %eax,%eax + EXIT +ENDPROC(__put_user_8) +EXPORT_SYMBOL(__put_user_8) + +bad_put_user: + movl $-EFAULT,%eax + EXIT +END(bad_put_user) + + _ASM_EXTABLE_UA(1b, bad_put_user) + _ASM_EXTABLE_UA(2b, bad_put_user) + _ASM_EXTABLE_UA(3b, bad_put_user) + _ASM_EXTABLE_UA(4b, bad_put_user) +#ifdef CONFIG_X86_32 + _ASM_EXTABLE_UA(5b, bad_put_user) +#endif
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